key: cord-0034081-fwtrahj9
authors: nan
title: Abstracts of the 9th Congress of the International Pediatric Nephrology Association, August 30–September 4, 1992, Jerusalem, Israel
date: 1992
journal: Pediatr Nephrol
DOI: 10.1007/bf00874026
sha: 50626dff4f0b32a62f1fd4c62583effa71cd6b50
doc_id: 34081
cord_uid: fwtrahj9

nan

Welcome to the Ninth Congress of the International Pediatric Nephrology Association in Jerusalem.

We have attempted to cover the wide array of pediatric nephrology issues in a number of state of the art lectures, symposia, oral free communications and poster presentations which will be followed hopefully by lively discussions.

We are deeply grateful to our senior colleagues and the international scientific council all over the globe who were kind enough to review the submitted abstracts and grade them on their scientific merits. In accordance with the suggestions of the IPNA council the vast majority of free communications are to be presented in poster sessions and only a few have been selected for oral presentation.

Much of the data, views and ideas, are innovative. Much of the information is confirmatory and aiL presentations are intended to contribute to the advancement and understanding of nephrology in the pediatric age group.

To the select body of former IPNA presidents, the council members and secretary, to the international scientific committee and to our many friends who have given us both help and advice in the construction of the scientific program, and last but not least to the authors of the papers to be presented -our heartfelt thanks. Although urinary tract obstruction is an important cause of renal failure in infants and children, its pathophysiology remains poorly understood.

Experimental studies indicate that severe fetal urinary tract obstruction can result in irreversible maldevelopment of the kidney (dysplasia), and less severe obstruction can impair renal growth.

Unilateral ureteral obstruction (UUO) causes immediate changes in renal oncegene expression, as well as early perivascular expression of SGP-2, a gene associated with "programmed" cell death, or apoptosis (I). It is likely that these events are enhanced in early development, thereby contributing to the increased susceptibility of the maturing kidney to obstruction.

Studies in the developing guinea pig showed that chronic partial UUO causes a more severe reduction in ipsilateral glomerular filtration rate (GFR) the younger the animal at the time of obstruction, whereas the adaptive increase in GFR of the contralateral kidney is also greatest in the youngest animals (2) . This exaggerated counterbalance in early development is presumably due to the unique characteristics of the maturing kidney.

Removal of the opposite kidney at the time of ureteral constriction in the neonatal guinea pig prevents the renal functional deterioration of the kidney with ipsilateral UUO (3) . The initial response to UUO is an increase in renal pelvic hydrostatic pressure, which is transmitted to Bowman's space and contributes to the decrease in glomerular filtration rate.

In the neonatal guinea pig with chronic partial UUO, the decrease in GFR is due also to a reduction in the ultrafiltration coefficient (4) .

Many animal studies have demonstrated the importance of renal vasoconstriction in the renal dysfunction resulting from UUO or bilateral ureteral obstruction (BUO).

Renal blood tiow (RBF) in guinea pigs with ipsilateral partial UUO from the time of birth fails to increase with age, as occurs with normal maturation (3) . Angiotensin II plays a central role in mediating vasoconstriction in the obstructed kidney, and is particularly important in the developing kidney, in which the activity of the renin-angiotensin system is normally increased.

Over 50 years ago, Beckwith (5) demonstrated that extracts of kidneys from rats with UUO induce hypertension when injected into normal animals.

Moreover, inhibition of angiotensin II formation by administration of enalapril to neonatal guinea pigs with UUO prevents the decrease in RBF of the ipsilateral kidney (6) , an effect that can be duplicated by inhibition of angiotensin II receptors with DuP 753.

Chronic administration of enalapril also prevents the reduction in glomerular volume resulting from ipsilateral UUO (7) .

In both kidneys of 1 month-old rats subjected to complete UUO at birth, immunoreactive renin is redistributed along the afferent glomerular arterioles in a pattern similar to that of the fetus , rather than being confined to the normal juxtaglomerular region (8) .

However, although renal renin content is increased in the obstructed kidney, it is suppressed in the opposite kidney.

This suggests storage of active renin in the obstructed kidney, and inactive renin in the opposite kidney.

Renin gene expression is also increased in the obstructed kidney, an effect that is modulated by renal nerve activity (9) . In contrast, UUO in the adult rat does not result in redistribution of renal microvascular renin or an increase in renin gene expression, underscoring the importance of maturation in determining the response to UUO (I0) .

Preliminary studies also indicate that angiotensin II receptor gene expression (AT1 subtype) is increased in the rat kidney subjected to ipsilateral neonatal UUO (II) . Moreover, renin secretion by the obstructed kidney is also enhanced, and this is the result of recruitment of greater numbers of renin-secreting cells (12). Thus, cellular and molecular studies further support a role for the renal renin-angiotensin system in mediating the vasoconstriction resulting from UUO.

Since RBF depends on the net balance of vasoconstrictors and vasodilators, it is necessary to consider their respective contributions to renal vascular tone.

Some of the vasoactive compounds may be released by infiltrating leukocytes as well as by the glomeruli themselves (13).

These include prostaglandins and thromboxanes, which may in turn be synthesized in response to increased local renin release.

Additional vasodilators that are produced by the obstructed kidney include atrial natriuretic peptfde and nitric oxide. Interestingly, renal synthesis of nitric oxide appears to be increased in response to UUO and decreased by BUO (14, 15) . In contrast, expression of the kallikrein gene is suppressed by ipsilateral UUO (16) .

Renal blood flow to the obstructed kidney is therefore determined by the complex interrelationships of multiple hormonal and paracrine systems.

Most importantly, the rapidly growing maturing kidney appears to be even more susceptible to these interactions than that of the adult.

i. Conner, J., Buttyan, R., Olsson, C.A., D'Agati, V., O'Toole, K., and Sawczuk, I.S. (1991 ) Kidney Int. 39, 1098 -1103 Kidney development is driven by multiple cellcell interactions. At onset of development, the kidney rudiment is composed of a mesenchyme and an epithelium, the ureter bud. The mesenchyme stimulates the ureter epithelium to grow and branch into the mesenchyme, and the ureter bud cells Stimulate a part of the mesenchyme to form a new epithelium. This new epithelium will gradually develop into the distal and proximal tubules and into the different epithelial cells of the glomerulus (i) . The newly formed epithelial cells will stimulate both the differentiation of the stroma and the ingrowth of blood vessels. The different types of cells gradually begin to produce extracellular matrix components typical for each tissue compartment (2) (3) (4) (5) .

The molecular basis of the different types of inductive interactions during renal development that have remained largely unexplained. The best studied event so far is the conversion of the mesenchyme into tubular and glomerular epithelium.

When the mesenchyme converts into a new epithelium, a large number of genes typical for epithelial cells will gradually be expressed. One of the earliest events is an increased cell proliferation (6) (7) . The expression of the c-myc protooncogene correlates with cell proliferation. The cells also express the N-myc protoonco~ene at early stages, but N-myc expression is more transient than c-myc expression. Taken together, these studies suggest that c-myc could be involved in proliferation, while N-myc together with other transcription factors could be controlling the conversion of the mesenchyme into epithelium. One possibility is that N-myc stimulates genes important for epithelial cell morphogenesis (7) . At later stages, when the cells convert into a polarized epithelium, the expression of cell adhesion proteins typical for epithelial cells (laminin, E-cadherin) increases. The laminin isoform produced by developing kidney epithelial cells has the chain composition A-BI-B2. The cells also produce the a6bl integrin. Antibody perturbation experiments suggest that this integrin is required for the development of kidney tubules and it could act by binding to the carboxyterminal ends of laminin A-BI-B2 (2) (3) (4) (5) . It would thus be important to identify transcription factors that stimulate synthesis of laminin chains and their receptors.

The principal secondary glomerulonephritides of childhood are vasculitis, mainly Schonlein Henoch purpura, and systemic lupus erythematosus. Probably these form about 5% of unselected patients with glomerular disease in children, but a much larger and variable proportion of referral practice in University or other tertiary centres.

Lupus nephritis in childhood usually presents after the age of i0, and presentation under 5 years is very rare. More males (F:M ratio 4.5:1) are affected than in adult-onset cases, but the ratio is the same in p~epubertal and pubertal children. The incidence of clinically evident renal disease is greater at onset than in adults (82%, the usually presentation being with proteinuria, 50% with a nephrotic syndrome. Half the children show WHO class IV nephritis in renal biopsies. Neuropsychiatric lupus is present at onset in 30%, may complicate 50% at some point, and remains a major problem. Prognosis has improved greatly over the past 30 years, at least in part the result of immunosuppressive treatment.

Treatment of the initial phase may be guided by the severity of the renal biopsy appearances, more aggressive treatment including cytotoxic agents, i.v. methylprednisolone and perhaps plasma exchange, although the value of exchange is not established. Controversy persists as to the most effective cytotoxic treatment in the acute phase, both oral and i.v. cyclophosphamide and azathioprine being used in different units. In the chronic maintenance phase, it seems established both clinically and histologically that addition of a cytotoxic agent improves outcome, but again the drug and route of administration are contentious. Azathioprine has the advantage of being safe for pregnancy and not gonadotoxic, whilst intravenous cyclophosphamide has been demonstrated to improve results over prednisolone alone in controlled trials, and has advantages in non-compliant patients. No trial comparing the two regimes has been done, and one is needed.

Today children much less commonly go into renal failure, and the main causes of actual death (15% of patients over i0 years) are now infections and extra renal manifestations of lupus, principally neurological. Morbidity of the disease and the treatment remains a major problem, especially when treatment exacerabtes complications of the disease itself such as infections, osteonecrosis, thrombosis, vascular disease and possbly neoplasia.

The immunopathology of lupus continues to excite much interest and investigation, and attention has turned away from the idea of glomerular deposition of preformed circulating complexes towards binding of anti-DNA and other autoantibodies directly to glomerular cells and matrix, possibly through antigen bridging by DNA itself, or by histones. Attention has also turned to events in the interstitium of the kidney in lupus, in view of the extensive interstitial infiltrate and the correlation between outcome and interstitial histological events.

There have been few advances in our understanding of Schonlein Henoch purpura, and the role (if any) of the IgA so constantly deposited in the glomerular mesangium in this and idiopathic IgA nephropathy remains unknown 30 years after its first description. This IgA distinguishes SHP from almost all other forms of vasculitis in C 3O which (apart from occasional post infectious or tumor-associated cases) immunoglobulins and complement are absent from the glomeruli. Anecdotes of transformation and familial coincidence of IgA nephrpathy and SHP nephritis have supported the identity of these two conditions: however some differences remain, in particular the fact that autoantibodies against a number of autoantigens are present in IgA nephropathy, but surprisingly absent in the systemic form of IgA-associated nephropathy-SHP nephritis.

We have examined recently the very long term outcome (mean followup 23.4 years)of a group of children first seen in London and Birmingham from 1962 to 1969. Some patients renal status deteriorated between 5 and 20 years of evolution, and 16/44 pregnancies were complicated by hypertension; thus some supervision of patients with SHP nephritis is necessary almost indefinitely.

The treatment of SHP nephritis remains controversial:

it seems clear that the great majority of patients neither require nor benefit from treatment. However the severe forms, especially those with extensive crescent formation, may respond to immunosuppressive treatment, inlcuding i.v. methylprednisolone and perhaps plasma exchange, although the evidence remains anecdotal.

Other fo;ms of vasculitis such as Wegener's granuloma or microscopic polyarteritis are rare in childhood; Kawasaki disease almost never gives rise to associated glomerulonephritis.

After a long period during which few new data on renal vasculitides emerged, better understanding of the immunopathology has emerged. Evidence of susceptibility based on race and NLA typing suggests an inherited component. The prominent perivascular and interstitial cellular infiltration with macrophages and monocytes suggests that delayed hypersensitivity reactions may play a role with T cells sensitised against vascular components a critical event.

Of particular interest have been descriptions of autoantibody systems in vasculitis, which seem to be specific to vasculitis and therefore diagnosticallyuseful.

The anti-neutrophil cytoplasmic antibodies (ANCA) have been intensely studied in recent years, and whether pathogenetically significant as well as useful in diagnosis and prognosis remains a matter for debate. The possibility certainly exists that these antibodies directed against neutrophil granular components such as proteinase 3 and myeloperoxidase can not only react with their ligand on the neutrophils and activate them, but also perhaps react with myeloperoxidase fixed on endothelial cells. In parallel, anti endothelial cell antibodies have been described, but the antigens on the endothelial cells with which they react are not yet identified and their role (if any) in pathogenesis remains even more obscure.

Clinical classifications of renal vasculitis remain controversial, especially whether or not Wegener's granuloma represents a different disease from renal microscopic polyarteritis.

Some support for their being two individual conditions comes from the finding that the majority of cases of wegener's granuloma show ANCA directed against proteinase 3 (C-ANCA), whereas the majority of those patients thought to have polyarteritis show P-ANCA patterns, mainly the result of anti-myeloperoxidase antibodies but also other targets such as elastase. However there are exceptions to these findings in every series. In SHP nephritis, IgA isotype ANCA have been found by some workers but not by others. There is now good evidence that fluorescence negative crescetic nephritis is usually ANCA poitive and represents a renal-limited form of vasculitis.

There are some suggestions that vasculitis is becoming more common, but increased awareness and the availability of ANCA have undoubtedly increased awareness of the disease. In children, those with vasculitis other than SHP nephritis are often suspected at least initially of having this much commoner syndrome.

The prognosis for patients of all ages with renal vasculitis has improved with judicious use of intense immunosuppression, but they may suffer infectious of other complications of treatment, and even die of them, even though they have recovered or retained renal function. Transmembrane signalling refers to the process whereby a hormone or other ligand binds to the external surface of the cell and without necessarily penetrating the cell membrane elidits a physiologic response specific for that hormone or cell type. Five major signal transduction systems have been well characterized in responses of the kidney. These include -adenylate cyclase (e.g. vasopressln-V2 receptor stimulation of hydro-osmotic water flow in the collecting tubule). -guanylate cyclase (e.g. atrial natriuretic peptide receptor coupling to vasorelaxation in the glomerulus or inhibition of sodium reabsorption in the medullary collecting tubule).

-inositol phospholipid hydrolysis (e.g. angiotensin II receptor coupling to mesangial contractile response).

-ion channel activation (e.g. leukotriene modulated apical sodium channel activation).

-tyrosine kinase signalling (pleotropic effects of epidermal growth factor receptor activation in the glomerulus and along the tubule).

For each of these signalling systems, ligand binding specificity is conferred by the extracellular ligand-binding domain of the receptor. Following receptor occupancy, the signal is transduced across the cell membrane resulting in a cascade of biochemical events that eventuates in the cellular physiologic response.

The current presentation will focus specifically on transmembrane signal transduction via receptor tyrosine kinases. These have been shown to subserve both mitogenic (e.g. activation of nuclear proto-oncogenes, proliferation, hypertrophy and transformation) as well as metabolic (e.g, eicosanoid production, modulation of solute transport) responses. Two specific examples will be discussed to illustrate the role of receptor tyrosine kinases in modulation of renal function. These are the role of the fibroblast growth factor receptor in nephrogenesis and the role of the epidermal growth factor receptor in the modulation of eicosanoid production.

The family of fibroblast growth factors and their receptors have been shown to be causally involved in mesodermal development and in differentiation of cells of mesenchymal origin. In situ hybridization studies have revealed a temporally and spatially~estricted pattern of expression of different members of the fibroblast growth factor receptor family during mouse kidney development. This has motivated studies to isolateregulatory elements from genomic DNA in an effort to identify transcription activating factors responsible for differential expression. Using information gleaned from these studies, it will be possible to probe individual steps in nephrogenesis and in particular the response to newly described epithelial morphogens (e.g. epimorphin and hepatocyte growth factors among others).

Epidermal growth factor action has traditionally been thought of in terms of growth and development responses. While these are of crucial importance in the developing kidney, there also appears to be an important role for this growth factor receptor in modulation of glomerular function in the mature kidney. This modulation of glomerular hemodynamics and glomerular cell proliferation appears to occur through the action of arachidonic acid metabolites. Site directed mutagenesis approaches have clarified the structural specificities within the EGF receptor for coupling to activation of phospholipase A2. More recently, with the availability of the gene encoding cytosolic phosphelipase A2, it has been possible to discern in greater detail the modulation of phospholipase A2 at both the transcriptional as well as post-translational level in response to EGF and other mitogens. These new findings and insights will be reviewed.

Finally, it is important to note that numerous disease states can now be understood in terms of perturbations in normal transmembrane signalling pathways. Examples include acute cyclosporine nephrotoxicity, glomerular hyperfiltration in diabetes mellitns, nephrogenic diabetes insipidus among others. Past, Present & Future of Renal Replacement Therapy (RRT) in Children. Fine, Richard N., Dept. of Pediatrics, State University of New York at Stony Brook, New York, USA.

Although chronic dialysis and renal transplantation became available as RRT for adults in the early 1960s, it was not until the late 1960s and early 1970s that specific programs directed toward pediatric patients requiring RRT evolved in North America and Europe.

Initially, specific equipment was not available to undertake dialysis in all the various pediatric age groups.

In addition, limited experience led some individuals to question the anticipated quality of life resulting from RRT in pediatric patients. The psychosocial consequences of RRT were considered to be so overwhelming for the patient and family that the wisdom of embarking on therapy was seriously in doubt.

Nonetheless, during the decade of the 1970s the technical obstacles were resolved, specific pediatric RRT programs evolved and a generation of pediatric nephrologists were trained to provide RRT children with end-stage renal disease (ESRD).

Although the technical capability to perform intermittent peritoneal dialysis (IPD) was available, hemodialysis (HD) was the dialytic modality of choice for pediatric patients until the 1980s when continuous ambulatory peritoneal dialysis (CAPD) and subsequently automated peritoneal dialysis (APD) were developed.

The availability of RRT for pediatric patients focussed attention on specific consequences of uremia that heretofore had received minimal clinical attention.

Specifically, renal osteodystrophy (ROD), growth retardation, anemia and mental development were identified as clinical consequences requiring significant attention.

An adequate vascular access was required in order to proceed with chronic HD.

Initially, external shunts were used which frequently clotted creating anxiety regarding the availability of additional patent vessels.

The development of the internal fistula was a major advance in providing long-term vascular access and alleviating the anxiety of potential shunt malfunction.

As with adult recipients, allograft rejection was the major cause of allograft loss; however, noncompliance with immunosuppressive drug therapy in pediatric patients was identified as a significant contribution to late (>6 months) allograft dysfunction and allograft loss.

A major issue in the early 1970s was the advisability of offerring RRT to infants and young children (<5 years of age).

The persistance of growth retardation and the side effects resulting from cortieosteroid therapy were identified as major adverse consequences of renal transplantation.

Recurrence of the original disease in the allograft was an undesirable phenomenon that shed light on the pathogenesis of the disease affecting the native kidneys in some instances.

The decade of the 1980s produced remarkable advances in therapeutic modalities of RRT in children.

Allograft survival rates markedly improved with the introduction of cyclosporine.

Home dialysis utilizing CAPD and/or APD became the dialytic modality of choice for pediatric patients.

Because of the latter, infants and young children were no longer considered suboptimal candidates for RRT.

Growth retardation was minimized with the use of recombinant human growth hormone (rhGH) and the clinical consequences of anemia were eliminated with the availability of recombinant human erythropoietin (rHuEpo).

The use of pediatric cadaver donor (CD) kidneys was identified as an adverse risk factor for allograft outcome.

The incidence of mental retardation as a consequence of uremia in infancy was reduced following the identification of the possible relationshi p between aluminium intake and abnormal neurologic development.

Reduction in the use of aluminum containing phosphate binders also resulted in the disappearance of aluminum related bone disease.

Currently, the outlook of the pediatric patient requiring RRT is significantly brighter than in the past.

Dialysis can be performed at home thereby minimizing disruption in the patients' social and educational activities.

Renal osteodystrophy is avoidable with the newer Vitamin D analogues; the clinical consequences of anemia can be eliminated with rHuEpo; and the patients' growth potential can be realized with the use of rhGH.

Non-compliance with immunosuppressive drugs remains a major obstacle to long-term allograft function.

I believe that dialysis will be used less frequently in the future as a therapeutic modality of RRT.

The judicious use of Vitamin D analogues to avoid ROD, rHuEpo to prevent anemia and rhGH to prevent growth retardation will extend the period of conservative management until pre-emptive transplantation can be undertaken.

CD allograft survival rates will continue to improve thereby eliminating the need for liverelated donor transplantation.

Specific manipulation of the immune system will minimize the need for continuous immunosuppressive drug therapy.

The latter will be exceedingly important for the pediatric patient because non-compliance will be minimized as a potential cause of long-term allograft dysfunction.

Leon G. Fine and JiIi T. Norman Department of Medicine, University College and Middlesex School of Medicine, London, U.K, It has become evident that all of the major peptide growth factors are produced in the kidney. Their putative sites of production are:-*Epidermal Growth factor (EGF) Thick limb of Henle's Loop; *Transforming growth factor a(TGF ~x ) Uncertain -? resident macrophages. *Transferring growth factor fl (TGFfl) Coltecting duct, proximal tubule *Insulin-like growth factor I (IGF-1)

Medullary Collecting duct *Insulin-like growth factor 1I (IGFJI) Diffuse in foetal kidney *Platelet-derived growth factor (TDGF) Mesangial ceils, collecting duct *Fibroblast growth factors. Uncertain

In addition a variety of other cytokines (interleukins, tumour necrosis factor etc) contribute to the array of growth-regulatory molecules available to pm~Jcipate in the response of the kidney to injury. There are also unidentified factors released by renal tubular cell lines in response to changes in No* and K + concentrations which may turn out to be normal growth factors with specific roles in renal regulation.

Acute Renal Injury leads to dedifferentiation of tubular cells or mild necrosis depending upon the severity of injury~ Regeneration of tubular epithelium must be driven by a mitogenic stimulus. Thus far only EGF has been studied systematically. In this context Renal EGF expression is decreased after acute tubular necrosis but the EGF receptor is up-regulated in viable cells. Immuno-detectable EGF is increased in cells which normally do not express the growth factor (eg proximal tubule) suggesting that enhanced EGF binding plays a role in the mitogenesis. The source of this EGF is not clear but is probably from the circulation. TGF ~x may also activate EGF receptors and this may arise from infiltrating cells. Exogenous EGF has been shown to accelerate recovery from acute tubular necrosis in the rat. However, in recent studies (Killion, Canfield, Norman, Fine and Rosenthal, Abstr. Am Soc Urol 1992) autotransplanted, ischemic pig kidneys failed to recover at an accelerated rate if exposed to EGF during the 72 hour period of cold-ischemia despite evidence of a mitogenic response to the EGF. The utility of EGF in a clinical setting remains uncertain. Future evaluation of TFG ~x, insulin like growth factors and PDGF alone or in combination may provide alternatives for therapy.

The multiplicity of factors which contribute to glomerular and interstitial fibrosis, tubular atrophy and hypertrophy and vascular obliteration will be extremely difficult to unravel. Current research has focused upon demonstrating whether or not the expression of given growth factor or cytokine is increased in a certain disease and upon where this expression localizes in the kidney. Almost all reported results are positive. In the glomerulus there is increased expression of PDGF, TGFfl and possibly IGF-1 in various models of renal disease. Likewise early evidence suggests increased PDGF expression in the interstitium in many diseases in which this compartment is involved. Because prognosis in many forms of human disease shows a closer relationship with the degree of interstitial scarring and tubular atrophy than with glomerular scarring, the mechanisms underlying the former process need to be investigated. Existing possibilities include damage to peritubularcapillaries or absorption of filtered protein both of which could induce tubular damage and atrophy. Since tubular cells express growth factors (EGF, IGF-1, PDGF, IL6, GM-CSF) it is not difficult to conceive of how such injury may set up paracrine stimuli to cause fibroblast proliferation extracellular matrix deposition and attraction of monocytes macrophages and polymorphs into the interstitial compartment.

A challenge for future research on both glomerular and interstitial injury will be to define the spatial and temporal cascades which lead to the recruitment of a large array of growth factors and cytokines into areas of injury and which ultimately lead to scarring and loss of function.

On the basis of extensive in vivo and in vitro studies in human and animal models of ADPKD and ARPKD, it appears that tubular cyst formation and progressive enlargement are related to increased epithelial cell proliferation and abnormal fluid secretion. Recent data suggest roles for abnormal growth factor responses and solute pump activity in these processes in cystic epithelia.

In ADPKD cystic epithelial cells studies in vitro, epidermal growth factor (EGF) appears to be an important autocdne regulator of inappropriate epithelial cell growth. ADPKD cyst epithelial synthesize and secrete EGF into cyst fluid and are mitogenically hypersensitive to the growth factor. ADPKD epithelial cells demonstrate high affinity EGF-receptors on apical membranes, where they are in direct contact with cyst-fluid EGF. Similarly, in human and murine models of ARPKD, abnormal quantitative (increased amount) and qualitative (apical membrane location) of EGF-receptor expression has been reported. In ADPKD cystic epithelial in vitro, abnormalities in NaKATPase expression appear to mediate tubular fluid secretion. A complete reversal of Na + pump polarity has been demonstrated, with active apical NaKATPase activity driving vectorial transport of Na + in a net basal to apical direction. In murine models of ARPKD additional abnormalities of NaKATPase expression have been demonstrated. Increased Na + pump activity and apical NaKATPase expression have been noted in cystic collecting duct epithelium in a marked exaggeration of normal tubular developmental profiles. Thus, both abnormal growth factor responses and altered Na pump activity appear to be features of the cystic epithelial phenotype in both ADPKD and ARPKD.

Advances in both "reverse genetics" and study of the cellular biology of cystic epithelia will converge in the near future to clearly delineate the molecular pathophysiology of ADPKD and ARPKD. Urolithiasis in children, although a world-wide problem, has received scant attention until recent years.

Previously believed to be due primarily to urinary tract infections, anatomical abnormalities of the genitourinary tract or hereditary metabolic disorders, it is now known that most children have urolithiasis in association with idiopathic hyperexcretion of lithogenic salts or underexcretion of natural inhibitors of urinary crystallization.

The prevalance and pathogenesis of urolithiasis varies greatly among regions and climates; however, the potential for long-term morbidity and renal injury exists in all populations.

In order to mitigate the consequences of urinary stones in children, we must identify children at risk, correctly diagnose urinary excretory abnormalities and treat stone episodes with therapeutic modalities possessing a low risk-benefit ratio. This symposium will address each of these challenging areas and present new information that will be useful to pediatric nephrologists and urologists.

DIAGNOSIS: Hypercalciuria has been identified as the most common abnormality in both children and adults with urolithiasis.

Normal values for older children have also been used in neonates and infants.

Professor Willem Proesmans will present studies clearly showing that urinary calcium excretion in infancy differs from older children. These data raise questions concerning previous reviews utilizing normal values from older children, that ascribe hypercalciuria as the etiology of nephrocalcinosis during infancy.

In addition, Professor Ernst Leumann will discuss normal oxalate excretion in early life and provide useful diagnostic criteria for assessing urinary stone patients. GENETIC RISK:

It has long been known that urinary stone disease frequently affects multiple family members of consecutive generations.

Professor Giuseppe Bianchi will present exciting new data concerning cell membrane markers for urolithiasis. Implications for the identification of children at risk for urinary stones will be discussed.

THERAPY: Application for non-invasive lithotripsy techniques has had particular appeal for pediatric patients who may have a life-time of risk for recurrent urinary stones. Dr. Dieter Latal will describe an extensive pediatric lithotripsy experience and offer therapeutic recommendations for children with urolithiasis.

Concern is now being raised about potential toxic effects of shock-wave therapy.

Dr. Sharon Andreoli will present experimental data evaluating tissue injury from shock-waves. As evidenced by these discussions, pediatric nephrologists and urologists are becoming increasingly sophisticated in their diagnosis and management of children with urolithiasis. Data on urinary calcium excretion in the young infant are scanty. We studied the urinary calcium/creatinine ratio in 102 healthy newborns. Were included babies born after uneventful pregnancies with a gestational age of 38 to 41 wks. Urine samples were collected twice in each newborn, one o~n day 4 (to avoid the influence of peripartal factors) the other on day 5 (most mothers leave the maternity hospital on day 6).

There were 52 boys and 50 girls; 64 were breast fed, 36 received formula feeding and 2 both types of milk. In 47 cases, the mother had received vitamin D during her pregnancy. Altogether, 185 urine samples were analysed. The median urinary calcium (Uca) concentration was 1.2 mg/dl (range 0.2 -30) or 0.3 mmol/I (range 0.05 -7.5). Median urinary calcium/creatinine ratio (Uca/cr) was 0.06 mE/mE (range 0.005 -2.3) or 0.18 mmol/mmol (range 0.15 -6.6).

!. Role of gender : Uca and UcaJcr values were similar in boys and girls. 2. Role of milk : formula fed babies had a median Uca of 0.6 mg/dl (0.15 mmol/I) and an median Uca/cr of 0.04 ram/mE (0.10 mmol/mmol) whereas breast fed children had a median Uca of 1.4 mg/dl (0.35 mmol/I) and a median Uca/cr of 0.08 mE/mE (0.24 mmol/mmol) : these differences are statistically significant (p<0.001). 3. Influence of Vit D supplementation : Uca and Uca/cr values did not differ between the babies of the mothers with vitamin supplementation as compared to those without. 4. Surprinsingly, there were significant differences between the samples collected on day 4 as compared to those obtained on day 5. Mean Uca/cr was 0.05 mE/mE (0.14 mmol/mmol) on day 4 and 0.068 mE/mE (0.19 mmol/mmol) on day 5 (p<0.00t).

In conclusion, healthy newborn babies have extremely variable urinary calcium excretions (expressed as calcium/creatinine ratio on samples). The data obtained in this study show no differences between boys and girls and no differences according to whether or not the mothers had been given vitamin D supplements during pregnancy. Yet, the Uca and Uca/cr values are significantly higher in the breast fed than in the formula fed babies.

S-1.3

Umversi~ Chil~en's Hospit~, Stem~eas~se 75,'CH-8II3~ Zurich, S~tzerl~d Nephrocalcinosls and urolithiasis are increasingly recogoized in paedistrie patients. Since any elevation Of urinary oxalate (Ox) concentration contributes considerably more to calcium oxalate (CaOx) saturation and hence to the risk of CaOx deposition than does calcium, attention is focussed on urinary Ox. Reliable methods (enzymatic and HPLC) are now available. Urines are best collected into bottles containing 6 N HC1 in order to attain pH <2.Neglecting acidification or using older eolorimetric methods may yield spurious results. Ox excreEion in 24 h urines obtained in over 400 normal children aged 2-15 yea~s (1) showed similar mean values for the different age grmups (range 0.30-0.39, mean 0.33 mmol per 1.73 m 2 surface area (SA)). These values are close to those (0.30 +/-0.08 SD) reported in adults (2) . For infants, data are scarce. Eleven preterm infants aged 4-8 days (mean birth weight 2.1 kg) excreted between 0.06 and 0.40 mmol per 1.73 m ~ SA (mean 0.19) . Ox excretion thus parallels SA, the upper limit of normal being 0.5 mmol (45 mg)/24 h per 1.73 m ~. Since accurately timed urine collections are difficult to obtain, data for Ox are usually related to urinary creatinine (Cr). These ratios, being log normally distributed, are far higher in infants than in older children (3, 4) . This decrease through-ouE childhood is to be expected since Cr excretion is proportional to weight and not to SA (3), e.g. a 5 kg infant would excrebe 1/7 of adult oxalate yet 1/20 of adult crestinine. During the first ten days of life Ox/Cr ratios are rising and then remain constant up to two months. Higher ratios are seen in preterm infants than in term infants. This is accentuated after ten days by formula feeding as compared to breastmilk feeding, as is sho~n below:

Geometric mean molar Ox/Cr ratios (total number: lOl infants): (range for the whole group: 51-522 mmol/mol or 0.04-0.42 g Ox/g Cr).

Urinary Ox/Cr ratlos in healthy infants are as high as those seen in paed. pat. (age >l year) with primary hyperoxsluria. However, ratios do not overlap ~hen reference values are consulted thst are appropriate for age and the method used. Does Ox excretion in infants put them at higher risk of renal calcifications than adults? Neither the urinary Ox concentration nor the urinary CaOx saturation are necessarily higher. However, CsOx saturation (which depends on many other lithogenie and inhibitory substances) may easily exceed normal values under certain conditions, e.g. parenteral nutrition or dehydration. More work is needed in this field. Nephrol. 1990; 4:493-497 C 35 S-1.4 

Giuseppe Bianchi and Giuseppe Vezzoli, Chair of di Nephrology, University of Milan and Division of Nephrology Dialysis and Hypertension, Scientific Institute H San Raffaele, Milan.

Urolithiasis is an heterogeneous disorder in terms of chemical composition, metabolic background and etiology. Familial factors are certainly involved in causing renal stones. However, the genetic-biochemical mechanisms underlying this familial predisposition are not clear. The scope of this presentation is to discuss the available results on the cell membrane ion transport systems, measured in idiopathic hypercalciuria and hyperoxaluria, which are known to be important causes of stone formation. We have limited the discussion to these two conditions as, to our knowledge, they are the only ones where certain aspects of cell membrane function have been studied in detail.

The establishment of a possible link between a given cellular biochemical mechanism and a complex phenotypic trait such as hypercalciuria and hyperoxaluria would help in the detection of candidate protein abnormality(ies) or gene(s). This would be an appropriate approach in identifying the familial and genetic factors involved in stone formation, which at present are completely unknown.

Idiopathic hypercalciuria is defined as a 24 hour calcium excretion above 0.1 mmoles per kg body weight, in the absence of known causes. It is detected in about 40% of patients with calcium stones. Even when known causes are excluded, Ca intestinal hyperabsorption or impaired renal tubular reabsorption or increased bone resorption seem to play a different role in each patient. The distinction among these three different causes is crucial since treatment varies according to the primary mechanism. Certrain diagnostic tests may be of help but cannot eliminate uncertainty. The reasons for this uncertainty lie in the complex feedback mechanisms regulating calcium metabolism and renal excretion, which make it difficult to distinguish between primary and secondary events. If genetic factors are involved in causing this disorder, an abnormality in calcium transport across the cell membrane is a likely mechanism. However, we should measure calcium transport across the membrane of a cell which is not affected by the mechanisms (hormonal, humoral etc....) involved in calcium homeostasis. Erythrocytes are an appropriate candidates, providing the genetic mechanism involved in calcium transport across the plasma membrane is similar to that regulating calcium transport across the plasma membrane of the ceils (tubular, intestinal ..) directly involved in favouring an increased urinary calcium excretion.

We previously studied the renal abnormalities in ion handling causing a genetic form of hypertension in a rat strain and we showed many similarities between tubular cell and erythrocyte abnormalities. Therefore assuming that a genetic abnormality in ceil membrane calcium handling is present in human idiopathic hypercaiciuria, this abnormality must also be found in other cells.

We measured Ca-MgATPase activity and other Na transport systems across erythrocyte membrane. Compared to healthy controls the patients with hypercalciuria had increased Ca-MgATPase activity and Na-K pump activity. In patients with a history of kidney stones and controls there was a highly significant positive correlation between 24 hour Ca excretion and the activity of erythrocyte Ca-MgATPase (but not Na-K pump). Erythrocyte Ca-MgATPase and Na transports were not altered in the patients with secondary forms of hypercalciuria. Familial studies showed a significant positive correlation between mean values in parents and offspring for both Ca-MgATPase and urinary calcium excretion. These correlations were not found when tested between the two parents. These findings were in agreement with the hypothesis that the Ca-MgATPase abnormality represents an inherited defect of cellular Ca transport, related to the causes of idiopathic hypercalciuria. How can these findings help in detecting the genetic-molecular mechanisms of idiopathic hypercalciuria?

The genes coding for the different isoforms of Ca-MgATPases have been sequenced and DNA polymorphism can be studied within the patient groups with different values of Ca-MgATPase activity (which is due to changes in CaATPase component). Alternatively there are strains of rats with genetically determined forms hypercalciuria. We are studying the F2 population obtained by crossing hypercalciuric and normocalciuric animals in the attempt Io establish associations between DNA markers and urinary calcium excretion. As many of these markers have already been physically mapped in the rat chromosomes by synteny we can identify the region of the human chromosomes which is genetically associated with an increase in urinary calcium excretion. Therefore these methods can also be appliedto studies in humans.

Idiopathic hyperoxaluria occurs in 20-50% of patients with calcium-oxalate stones. Even though the dietary content of oxalate is important in determining the excretion, genetic factors must be involved in causing the variability of urinary oxalate in the individual patients maintained on a diet with a fixed amount of oxalate. Oxalate transport in erythrocytes may be evaluated as self exchange through plasma membrane. Borsatti and coll. found a more rapid oxalate trasport was found in the 70% of the patients with idiopathic Ca-oxalate urolithiasis. In spite of its high frequence in urolithiasis the defect was not correlated with urine oxalate excretion, but was associated to a faster excretion of oxalate after an oral load. In the patients with primary hyperparathyroidism or genetic defect of oxalate metabolism enzymes, oxalate transport was not altered. In the families with urolithiasis the alteration of oxalate self exchange appeared to be genetically determined and segregated as an autosomal, monogenic, dominant trait with complete penetrance and variable expressivity. The inhibition of the transport by stilbenes showed that it occurred through membrane anion channel (band 3). Moreover, glycosaminoglyeans corrected the erythrocyte defect and reduced urine oxalate excretion. These findings suggest that in patients with urolithiasis there may be a defect in the cellular synthesis of glycosaminoglycans. This may cause a defect in the inhibition of protein kinase phosphorilation function and an increased phosphorilated state of band 3 and of its transport activity. There is evidence of an anion exchanger encoded by the same gene as that of erythrocyte band 3 in basolateral membrane of alpha intercalated cells of the collecting tubule. As this cell seoerned H +, the defect of th 9 anion exchanger may partly justify the alterations in urine acidification found in idiopathic urolithiasis. A difficult regulation of cellular pH was also shown in the lymphocytes of the patients with urolithizsis and hypercalcuria, who had low cytoplasmatic pH, but the cause of the alteration was not clear.

In conclusion blood cell alterations have been demonstrated in some forms of urolithiasis and these may be very useful intermediate phenotypes for the detection of the gene(s) involved in the causes of this renal disorder.

S-1.5

Extra corporeal shock wave lithotripsy (ESWL) has changed the management of urolithiasis in children entirely. Second and third generation lithotriptors permit universal treatment of renal and ureteric stones in children independent of age and size. A very small focal area facilitates accurate stone fragmentation without substantial tissue trauma. With the use of a large aperture, pain-free treatment without anesthesia becomes possible, through minimal compliance even at arotmd 4 years of age. Continuous ultrasound visualization not only avoids exposure to radiation but, due to the fact that the state of fragment-ation is well evaluable at any stage, also permits optimum energy application on an individual basis. ESWL is particularly effective in children since the energy flow meets with less interposing tissue.

From 1986 to 1992, 77 ureterorenal units in 70 children aged between 4 months to 15 years with 81 renal (size > 1.5era in 13 eases) and 30 ureteric stones were treated with 3rd-generation fithotriptors utilizing combined ultrasound and x-ray location systems. General anesthesia was needed in only 19% of the patients. Fragmentation was achieved in 95%, the stone-free rate after 3 months was 90%, and the re-treatment rate 1.5%. Stone fragmentation in children is excellent and fragment elimination surprisingly smooth as compared with that in adults.

The few cases, unresponsive to lithotripsy can be managed by endourologic surgery. Extremely thin endoscopes (4.8 Charr) combined with intracorporeal laser-based contact lithotripsy achieve a high success rate at low morbidity. Being the least invasive treatment, ESWL is the primary choice for treating urolithiasis in chi/dren. Although ESWL is g~nerally thought to be safe, several reports suggest that ESWL causes several acute adverse effects and may lead to chronic complications. Stone dissolution occurs as a result of the mechanical stresses generating by shock waves but these forces also induce acute and chronic tissue injury.

ESWL is thought to induce acute structural and morphologic changes in the treated kidney in the majority of patients receiving ESWL.

The Studies with cultured renal tubular epithelial cells in vitro have also demonstrated several adverse effects of shock waves including decreased viability, decreased ATP content and cell lysis.

Viability, ATP content and cell lysis were mildly affected after 50 shocks, moderately affected after 500 shocks, and severely altered following 1500 shocks. Although the mechanisms of renal injury resulting from ESWL are poorly understood, several possibilities exist including the mechanical forces that result in sheer stress and acoustic cavitation.

In addition, reactive oxygen molecules which are produced as a by product of acoustic cavitation may also play a role in the pathogenesis of renal injury. We and others have detected reactive oxygen molecules including the hydroxyl radical during ESWL.

Once the adverse effect of ESWL are defined and once the mechanism(s) of injury are understood strategies to prevent such injury can be formulated, REGULATION OF THE RENAL Na,K-ATPase BY PROSTAGLANDINS. R. Cohen-Luria, G. Rimon and A. Moran*, Departments of Physiology and Pharmacology, Faculty of Health Sciences, Ben-Gurion university of the Negev, Beer-Sheva, Israel. Prostaglandins of the E series induce diuresis and natrittresis. This effect is mainly attributes to inhibition of the antidiuretic hormone (AVP)-induced cAMP production in the cortical collecting ducts. In the present study a direct effect of PGE2 on ouabain binding and Na,K-ATPase activity in a clone of MDCK cells (established renal cell line that expresses properties of the renal collecting duct) is presented. Incubation of the cells with low concentrations (pM) of PGE2 produced a concomitant inhibition of Na,K-ATPase activity in the cell homogenate and reduction in ouabain binding to the intact cells. The half maximal concentrations of PGE2 for reduction of ouabain binding and inhibition of Na, K-ATPase activity were similar (IC50 of about 0.1 pM). Ten nanomolar of PGE2 caused maximal inhibition. At this concentration the activity of the Na,K-ATPase and ouabain binding was reduced by about 40-50%. The inhibition was apparent within 10 minutes of incubation of the cells with PGE2. Scatchard analysis of ouabain binding demonstrated that PGE2 treatment reduced the number of ouabain binding sites without a change in the dissociation constant (Kd = 366+-38 and 372247 nM; Bmax = 1.103-+0.114 and 0.557-+0.094 pmol/mg (P<0.01), for control and PGE2 pretreated cells, respectively). Ten nanomolar of PGE1 or PGF2a, (a concentration 10.000 fold the IC50 for PGE2) did not affect ouabain binding or Na,K-ATPase activity, suggesting that the inhibition of the Na,K-ATPase is rather specific to a PGE2 receptor. Treatment of the cells with NaF caused a dose dependent decrease in ouabain binding (40 and 80% for 13 and 50 mM NaF, respectively). Hence, it is conceivable that the mechanism of action of Na,K-ATPase inhibition involves activation of G proteins. Three lines of evidences indicate that an increase in intracellular cAMP is involved in the inhibition of ouabain binding: a. forskolin, a stimulator of the adenylate cyclase; b. di-butyryl-or 8-bromo-cAMP, permeable cAMP analogues; c. theophilline, IBMX and RO-20174, phosphodiesterase inhibitors. These agents inhibited ouabain binding similarly to the effect achieved by PGE2, in a dose dependent manner. The simultaneous addition of these agents with PGE2 did not have an additive inhibitory effect on ouabain binding, suggesting that cAMP is a possible mediator in this regulatory process of PGE2 on the Na, K-ATPase in these cells. The data are consistent with the notion that the mechanism of the diuretic/natriuretic effect of PGE2 in the collecting tubule, in addition to the inhibition of AVP activity, may result from a direct reduction in the number of the Na,K-ATPase active units via a prostaglandin receptor. We have previously demonstrated the existence of an inverse relationship between changes in [Pi] i, related to age or brought about by alterations in Pi supply, and changes in Na § cotransport. However, age related differences in [Pi]i alone could not explain the high rates of renal Pi transport observed during growth (Barac-Nieto et al. Am. J. Physiol. 261:F153, 1991) . We have therefore explored the possibility that GH contributes to the high rates of renal Pi transport by a mechanism independent of changes in [Pi]~. Net renal tubular transport of Pi (TPi) was measured in vivo, and the NMR-visible [Pi]i was measured in perfused kidneys of 8-week-old genetically GH-deficient dwarf rats (Harlan Olac, Bicester, England) , and in dwarf rats treated with GH (i00 ~g /day twice a day s.c., for 3 days). In addition, we evaluated the effect of insulin-like growth factor 1 (IGFI, i0 "8 M) on 32p uptake (TPi) Thus, in the whole animal, changes in TPi due to GH occur in the absence of significant changes in [Pi] }. In OK cells, the effect of IGFI on TPi is independent of changes in [Pi] ~ and is additive to that of low [Pi] ~.

Decrease in [Pi] ~ produced by incubation of OH cells in Pi-free medium was associated with 2-fold increases (P<0.05) in the pools of phosphodiesters, which are products of phospholipid metabolism, and of a 1~C-labeled metabolite of araehidonic acid (AA) that coelutes with synthetic 20-HETE. Inhibition of phospholipid catabolism via the monooxygenase P450 pathway (using ketoconazole i0 ~g/ml or SKF-525A 33 ~g/ml) reduced Na § cotransport by 70% (P<0.01), and 20-HETE (10 "6 M), a major product of P450 hydroxylase pathway in the proximal tubule, stimulated Na § cotransport by 200• (P<0.05 Cell imaging is a powerful new technology which permits to observe the changes in living cells in five dimensions: three dimensions of space, a dimension of time and a dimension of concentration of key components inside the cell. Recently confocal microscopy became a major too( in cells imaging. In confocal microscopy a fluorophore is loaded into cells, excited by a laser beam at the optimal wavelength and the emitted photons are detected by a photomultiplier. Between the celt and the detector there is an opaque plate with a small pinhole. Only photons that are at the focal distance form the pinhole can reach the detector. The usage of a pinhole (of variable diameters) permits an optical sectioning of a living and functional cells. Using conventional and confocal microscopy of nerve terminals, bone cells and pheochromocytoma cells, we shall illustrate the following apperatures of cell imaging. (.

Three dimensional reconstruction of cell shape of living and functional nerve terminals and of osteoblasts.

Imaging of intraceltular calcium in selected intracellular locations. Different synaptic boutons of the same cell exhibit different calcium behaviour.

Coordinated fluctuations and oscillations in intracettuler calcium concentration ([Ca] ,n).

[Ca]~~ is one of the main determinants of exocytofic secretion and thus of synaptic transmission in the nervous system. At rest its level is not constant but undergoes coordinated fluctuation of a large fraction of the terminal. These fluctuations have an oscillating behavJour, with a frequency of 0.5 Hz and 0.05 Hz.

Regulation of intracellular calc|um by extracellular ATP.

Variance analysis and new algorithms of cell imaging. 6 .

A study of cell-cell communication by fluorescence recovery after photobleaching.

Supported by the Israel Academy of Sciences and Humanities, the Muscular Dystrophy Association and the United States-Israel 8inational Science Foundation. Chronic: peritoneal dialysis (CPD) has been used extensively in children for more than I0 years. It is a proven method of dialytic therapy for the pediatric population, especially the very young child. However, there are complications encountered in CAPD/CCPD which are a challenge to the physician. The longterm complications directly related to CPD are addressed. Infect ions Many patients have exit-site infections (ESI) and scrne of these persist in spite of therapy.

Pseudomonas ESIs are particularly refractory to therapy. A persistent ESI can progress to peritonitis and certain bacterial infections can result in type I membrane failure (loss of ultrafiltration). Peritoneal adhesions can be a consequence of peritonitis and result in bowel obstruction. Sclerosing encapsulating peritonitis is a devastating chronic complication, which is fortunately rare in children. Hernias This is a problem which appears to be more prevalent in infants, however it occurs in all age groups.

In male infants the tunica vaginalis can be patent, which results in an indirect inguinal hernia. Inguinal hernias can be associated with labial or scrotal edema. The distinction between the two can be difficult, yet is inportant, as the hernia will require surgical repair, whereas genital edema may self-correct with a change in dialysis schedule.

Other types of hernias are incisional, the site of catheter placement, or r~nbilical. Because of the risk of bowel strangulation, they should be repaired. Pancreat it is Dialysis fluid can gain access to the lesser sac Of the peritoneal cavity via the epiploic fore, hen. Factors which can potentially irritate the pancreas ere: hypertonic dialysate, calciem in the dialysate, toxic by-products of the dialysis bag or tubing, or recurrent infection. Some episodes have resulted in pseudocyst formation. Discontinuation Of CPD is necessary. Psychologic Reactions T~ quality of life on CpD is an improve_went compared to hemodialysis. The children ere able to remain at home, attend school regularly, and participate in many sports. However, this improved lifestyle requires extra work, and this in turn adds extra stress on the patient or the family. Fatigue, or even depression, can evolve. For the older patient CPD may affect their body-image. In those patients who already have a growth disturbance, the problems related to body-image are compounded. Therefore, the children need encouragement while coping with these chronic psychological stresses secondary to CPD.

The following complications are related indirectly to CPD, since the uremic state per se can cause similar complications. Renal Osteodystrophy CPD does not prevent bone disease. Maintenance of normal sert~n ealci~n and phosphorous levels are necessary, and this requires supplemental calcit~n, vitamin D and phosphate binders. Renal osteodystrophy (ROD) can be more serious in younger children and can result in bone deformity. Children in whom ROD has been prevented usually are those who have the best growth velocity. Lipid Disorders Patients with chronic renal failure may already have an e~evated sermon cholesterol and triglyceride level. Continuous absOrptioN of ~ glucose will stimulate insulin'secretion which alters lipid met ~boliem. Perturbations in lipid levels are serious, since these patients will eventually receive a renal transplant, which will further increase the risk of at herogenesis. Growth and Nutrition Growth failure is common to children with chronic renal failure. CPD does not appear to correct the growth failure. In spite of adequate nutrition, there are other reasons for poor growth. There is hope that growth hormone therapy will ameliorate this serious problem.

CPD will remain as one of the preferred dialytic modes of therapy for children with ESRD. Most of the longterm complications can be prevented or reduced.

Such improvements will provide better overall therapy, and thus improved health for th~ children. Hemodialysis prescription in children needs on the one hand to choice the type of dialysis modality and on the other hand to determine the dialysis dosis prescription. Today, the dialysis modality is based on the recent technology advancements : conventionnal or highly permeable membranes (hydraulic and molecular permeabilities, area, biocompatibility), acetate or bicarbonate or buffer free (biofiltration, BF) dialysate, ultrafiltration control, diffusive (HD) or convective (hemofiltration, HF) or diffusive and convective (hemodiafiltration, HDF) epuration, ultrafiltration (UF) rate and/or sodium (NaD) dialysate modelling, compartimental epuration against water (NaD modelling) or phosphate (bicarbonate modelling) cellular sequestration. The first goal is dialysis tolerance specially weight loss over session : low extracorporeal blood volume (capillary membranes), UF control (volumetric) dialysate composition (NaD level and bicarbonate as buffer) and only for a few patients UF rate and NaD modelling can be used. The second choice is guided by the quality of epuration. A highly permeable membrane allows the combination of diffusive (low molecular weight compounds like urea) and convective (higher molecular weight compounds, middle molecular uremic toxins or B2 microglobulin) blood epuration during the same session time (HDF). Most of these membranes have high biocompatibility, only some of these ones are sterilisated without ethylen exyde. But despite a larger range of molecular weight compounds epuration (ie B2 microglobulin) and increement of cardiovascular stability (HF effect) conventionnal HDF with highly permeable membranes is only occasionnaly performed in children (expensiveness of these management). Perhaps on line HDF (restitution solution directly elaborated from the dialysate) will give a new chance to this very efficient (quality of epuration and tolerance) dialysis modality. Use of highly permeable membranes requires enhancement of dialysate purity (to limit retrofiltration adverse effects i e endotoxia) adjustment of dialysate composition (to limit buffer or calcium intoxication) and monitoring of the risk of fast epuration (osmotic syndrom). Today, dialysis dosis prescription is based on the normalized whole body urea clearance determinated by the ratio : urea cleared volume (KT) over urea volume of distribution (V). The goal is the adjustment of KT/V for the protein catabolic rate (PCRn nutrition and catabolism) to obtain a low urea time average concentration (TAC urea lower than 20mmol/l). Adaptation of the quality of epuration (KT/V, TAC urea) to the quality of nutrition (caloric versus protein intake, PCRn) offers to each dialysed child the highest chance to low dialysis morbidity or even mortality. Single pool urea kinetic modelling is the simplest way for calculation of : KT/V (delivered dialysis deals), PCRn (quality of nutrition, caloric versus protein intake) and TAC urea (dialysis adequacy). Because of the real but only relative inaccuracy of the single pool model, partial dialysate collection, direct calculation, percent reduction of urea over time, two hours post-session urea level (to avoid error of postdialysis urea rebound) and two pool urea kinetic modelling are proposed. Each of these calculations (except total dialysate collection) are approximations and so the results are more informative in the follow up of each patient as in the comparison of different patients. HD prescription in children has to choice the best technology modality adapted to each patient with respect of his cost. Assessment of the adequacy of HD in children has not only to take into account biological calculations (KT/V) but also to refer to clinical results (acute tolerance, long term morbidity). Infants with chronic renal failure and end-stage renal disease (ESRD) have attracted a great deal of attention from the pediatric nephrology community because of the high risk nature of these patients. Technological advances and increasing clinical expertise in the fields of dialysis and transplantation has maintained the controversy as to which of these techniques might be considered the optimum form of therapy in this population.

Multiple experiences substantiate the fact that the combination of peritoneal dialysis and intensive nutritional support regularly result in success in terms of growth in even the newborn infant with ESRD. Brewer recently described a prolonged experience with 14 infants who were treated with bng-term peritoneal dialysis and nasogastric tube feeding in which 4 patients had significant catch-up linear growth, defined by an increase of [.0 height standard deviation score (SDS) or more, and g patients either maintained or increased their height SDS to within the normal range. However, "complications" associated with this method of renal support can include delayed cognitive development, especially in those who develop RSRD in the first few months of Life, an aversion to oral feeding and a prolonged re!Jance on tube feeding. We described 5 cases in which i~tervention by a behavioral psychologist was necessary to assist the ultimate conversion to completely oral feedings while other children require intervention by an occupational therapist due to the infant's continued exhibition of immature oral motor patterns. Fina[Ly~ the 199l report of the United States Renal Data System (USRDS) establishes the 2-year patienL survival rat~ for the youngest dialysis patients (0-4 years) to be only 69%. The reasons for the high mortality rate a,e not completely understood, although there is suspicion that it might be related, in part, to an acquired alteration of the immune system (e.g. hypogammagiobuiinemia). A better uIlder~La,tdi,, Z uf ure~ kinetic modeling and its application in individualized prescriptions for dialysis and continued research on the altered immune status of the infant ~eceiving peritoneal dialysis is likely to modify both morbidity and mortality rates.

Clinical experience, predominantly gained in single centers, also supports the belief that early kidney transplantation (6-12 months of age) can be associated with good long-term patient and graft survival. Improvement in patient height, head circumferences and cognitive development may also result. Najariall st. al. reported 5-year patient and graft survival for infants receiving cyelosporine [o be i00% and 82%, respectively. A significant improvement in head circumference (OFC) SDS and cognitive development was also found in the 17 patients who were younger than 12 months of age when undergoing transplantation.

The mean OFC SDS at Lime of transplant was -1.9, whereas one year after transplant the mean OFt SDS had increased to -0.3 (p ~ 0.001).

Six infants had abnormal mental development prior co transplantation while all L5 infants re-evaluated following transplantation had normal mental development. Despite these excellent results, multicenter data continue to demonstrate signi-ficant[y poorer results in terms of graft and patient survival in the youngest recipients (O-i yr.) . The 1992 report (unpublished) of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) fou~d that very y$ung recipient age ( ~ 24 months) is associated with diminished graft survival in both cadaver (3- year graft survival: 45%) and five donor (3 year graft survival: 73%) transplants. The mortality rate of the youngest age group was also significantly greater than that found in any other age category.

In summary, peritoneal dialysis and renal transplantation are two forms of renal replacement therapy which complement one another and together form the optimum therapy for infants with ESRD. While long-term peritoneal dialysis is available to infants of any age, transplantation in children 6-12 months of age is also possible. In most cases~ however~ transplantation should probably he reserved for those patients who are do~Dg p@orly on diaSys~% or who are not achieving growth a~o/or ueve• mltestones. It is yet to determined whether and when infants should be grafted. Arguments pro and contra the delay of kidney transplantation will be pointed out. Criteria for optimal treatment should include patient and graft survival but have to stress somatic and psychosocial development. The graft survivals compare unfavourably to the results obtained in older children, especially in infants, which could be explained by the hightened non-specific immune reactivity in small children. Data on dialysis treatment in very small children are rare. In our own experience 2 children < 2 out of 4 years died on CAPD. Multicenter studies including all children with CAPD/CCPD reported a 1 year survival rate of 90%, which is comparable to the results of kidney transplantation. Other parameters like growth and mental development as well as the psychosocial strain on the child and his family have to be considered. In infants growth rates can be normalized by aggressive nutrition, i.e. nasogastric tube feeding. Daily subcutaneous application of growth hormone can achieve normal growth rates in older children on dialysis. Erythropoietin treatment eliminates the necessity of blood transfusions. New aspects with high dosages of calcitriol will improve the renal osteodystrophy. Conclusion: Renal transplantation in small children remains a challenge for pediatric nephrologists and the optimal timing of renal transplantation in small children depends on multiple preconditions. Recent progress with dialysis treatment may shift the balance towards continuous peritoneal dialysis, at least for children less than one year of age.

S-4.0 HEMOLYTIC UREMIC SYNDROME (HUS) ACUTE RENAL FAILURE (ARF).Introduction to the symposium. A.Iaina~ E.Liberman. Department of Nephrology. Tel Aviv Med.Ctr. ISRAEL.

The HUS is classically defined by the lriad of microangiopathic hemolytic anemia,thrombocytopenia and acute nephropathy.The syndrome affects patients of all ages but most are infants and children under of 4 years o[ age.The deliniation of the RUS was first made in 1955.Since then many cases have been reported fromendemic regions (Argentina,South Africa, The Netherlands,California, Bangladesh) .In these places the HUS is by far the most important cause of ARF in children. A retrospective study of flUS in Minne~ota,between 1979 Minne~ota,between -1988 demonstrated a mean anual increase of the disease from 5/mil child-years to 20/mil child--years. There is a tendency to classify HUS to primary and secondary forms.Primary HUS occurs predominantly in children,while secondary forms are common in the adult population.Three important variants of primary HUS were described:pro~otypic farm (85 X) mainly after infections,recurrent form (with platelet abnormalities) and familial form (either hypocomplementemin,platelet biochemical dysfunction or botb).An epidemiologic study in the State of Washington indicate a 25% incidence of HUS among children younger than I0 years with E.Coli 0157:H7 gastroenteritis.Other possible infection agents associated with HUS include:bacterial:shigella, salmonella,B hemoliticus streptococci, clostridium, yersinia;viral agents:coxackie,arboviruses, echoviruses,EBV.Otber: mycoplasma,leptospira. Pathophysiology. Two main pathophysiologic aproaches to the syndrome:the central event is damage to the vascular endothelium caused by the etiologic agent, or its toxin (verotoxin),leading to coagulation, fibrin formation in the lumina and capillary walls, mechanical damage to the RBCs with or without consumption of the platelets. Accordig to a second hypothesis,the damage to the glomerular endothelial cells,the RBCs and platelets caused by the same etiologic factor concomittantly. Symptomatology.After few days of prodromal phase, the onset of the disease is characterized by diarhea,fever,extreme pallor,purpura or bruising, lethargy and ARF.

[n 15 % hyperiension,seizeares and coma. ARF. The ARF in children with HUS varies between 2.2-53 X in different published series. There are three main categories of bystologic changes.The most common is the glomeruloendothelial injury seen in the epidemic HHS in infant and young children,clinically associated with hemolytic anemia and with only mild or no hypertension.A second form with cortical necrosis and severe renal insufficiency,w~th unfavorable renal outcom. A third form is the vascular type with severe interlobular arteries~appearance of lamelar anion skin like bodies and occlnssive lumen trombi.This variant is common in sporadic cases of older children and adults.Severe hypertension is very common. The hemathologic changes are less prominent.Some tines combined forms were described. Treatment When ARF is present dialytic therapy is mandatory.The most popular and successful mode of dialysi~ is peritoneal dialysis. Plasma infusions in patients with recurrent or familial HUS have been used,however in the typica] form of HUS plasma administration is still controversial.Preliminary observations suggest possible role for i.v.fg therapy. Outcome. The outcome of prototypica] farms improves,85Z recovers even when ARF is present.The mortality rate is below 5X ( 30 % 2 decades ago ). Many of those patients with the familial or the recurrent type who survive after the acute disease remain with renal function impairement and hypertension.Renal transplanted patients recieving Cyclo~por[n A may develop a recurrent episode of HUS.

Based on clinicial observations, it has been proposed that the irm~ture kidney is resistant to an anoxic insult. To test this hypothesis, tubule suspensions frcm inm~ture rats (8 days old) and mature rats (8 weeks old) were harvested after collagenase perfusion and exposed to either 45 or 60 minutes of anoxia. I/~ release was used as a measure of tubule oell injury and was approximately 10% in uninjured tubules frc~ both inm~ture and adult animals. In tubule segments obtained from mature rats, I/~ release was 35% and 45% after 45 and 60 minutes of anoxia, respectively. In coni0arison , tubules obtained from inm~ture rats had significantly (P < 0.01) less cell injury as demonstrated by LDH release of 20% and 25% after 45 or 60 minutes of anoxia. Similarly cellular ATP levels were markedly reduced in the adult tubules to levels which were 10% or less of control values. In comparison, however, cellular ATP levels were reduced to only 50% of control values in the in~ature tubules. These data would suggest that the inmature renal tubule is less susceptible to anoxia and that the preservation of cellular ATP is an important mechanism related to the maintenance of cellular integrity in inm~ture tubules.

Heat shock proteins are a group of highly conserved proteins which have been demonstrated to have cytoprotectant effects and to be involved in cellular rescue following a variety of noxious stimuli. Sublethal ischemia induce~ a variety of structural changes including the loss of apical brush border, cytoskeletal disintegration, and a redistribution of membrane proteins into a non-polar configuration. To determine if heat shock proteins might be involved in restoration of cellular integrity following an isc/lemic insult, we examined the induction, elaboration and distribution of HSP-72 in rat kidneys at 15 minutes, 2, 6 and 24 hours after 45 minutes of renal ischemia. The ischemic injury resulted in a marked induction of HSP-72 mRNA which peaked at 2 hours and declined to near basal levels by 24 hours of reflow. A small amount of constitutive HSP-72 was present in soluble, but not microsomal fraction of proteins obtained from uninjured kidneys. After 15 minutes of reflow, there was a shift from the soluble to mic~l fraction and frc~ 2 to 24 hours of reflow HSP-72 increased in quantity both in the microsfm~l and soluble fractions. Localization of HSP-72 by confocal microscopy demonstrated that the protein is restricted to the apical domain at 15 minutes, is dispersed throughout the cytoplasm in a vesicular pattern at 2 and 6 hours reflow and has migrated away from the apical domain toward the basolateral domain by 24 hours. These studies indicate that heat shock response is induced by an ischemic renal injury and the elaboration and localization of these proteins are consistent with the recovery of cellular structure and polarity after an ischemic insult. The specific pattern of localization suggests that HSP-72 may interact with misplaced or daz~aged membrane proteins or with cyteskeletal elements to assist in the stabilization, repair and repolarization of epithelial cells.

of Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, ISRAEL.

Thrombotic microangiopathy is the histopathological lesion common to HUS, thrombotic thrombocytopenic purpura and postpartum renal failure. While thrombi may involve multiple organs outside the kidney, such as brain, heart, gut and liver, the most significant Clinical problem is almost invariably acute renal failure. The reason for this remarkable predilection and the exact pathophysiological mechanisms responsible for kidney failure remain elusive. Although the etiologies for thrombotic m3croangiopathy are diverse (including bacterial toxins, chemotherapy, vasculitis, estrogens, cancer and radiation), a common denominator appears to be vascular and endothelial damage, with or without thrombosis, leading to renal hypoparfusion. While intraglomeruli thrombi are typical findings, tubular necrosis and atrophy are most often associated with severe, sometimes irreversible, renal failure. This discussion reviews recent knowledge suggesting that intrarenal regional hypoxia may play a major role in the vulnerability of the kidney to hypoperfusion.

The price land mammals pay for the ability to concentrate their urine is a renal medulla that is perpetually hypoxic. Renal medullary hypoxia derives from the countercurrent mechanism that permits not only solutes to be concentrated along a corticopapillary gradient but also oxygen to difi'u~e from the descending to the ascending branches of the vasa recta. In this region, the medullary thick ascending limb of Henle's loop (mTAL) avidly consumes oxygen for sodium chloride transport, necessary for the generation of concentration gradients. The net result is that renal medullary pO 2 falls to very low levels. In this hypoxic environment, the mTALs are particularly susceptible to excessive workload and may be a prime target of injury. By contrast, in the cortex, glomerular filtration and bulk reabsorption of solutes along the proximal tubule are supported by an exceptionally generous blood flow, which equals nearly a quarter of the total cardiac output. Because of high tissue perfusion, over the metabolic needs of tubules, cortical pO2 is generally high. Nonetheless, in this region, medullary rays (which are expansions of the renal medulla into the cortex) receive a substantial portion of their oxygen supply from desaturated blood ascending from the renal medulla and may also be particularly vulnerable to hypoxic injury, during renal hypoperfusion

Medullary oxygen balance appears to be regulated by multiple paracrine homeostatic mechanisms. Prostaglandin E2, released by the renal medulla in response to regional hypoxia, induces local vasodilatation and reduces transport work by the toTAL, thus reestablishing medullary oxygen balance. Adenosine, liberated from the breakdown of cellular ATP. -increases medullary blood flow while decreasing GFR, distal solute delivery and reabsorption workload, thus restoring medullary oxygen sufficiency. The endothelial-derived relaxing factor nitric oxide appears to play a major role in assuring basal tone of active intrarenal and medullary vasodilatation.

Endothelial damage interferes with these paracrine mechanisms and predisposes to focal hypoxic injury at sites of strategic importance for overall renal function. Most at risk for hypoxic damage are the mTALs and the st~igllt portion of the proximal tubule ($3), i, the outer medulla end in the medullary rays. Injury to Henle's loop may be particularly detrimental to renal function, because of activation of tubuloglomerular feedback and intraluminal obstruction by cast precipitation of Tamm-Horsfall protein (exclusively released by toTALs). Intrarenal hypoxia may play an important role in the susceptibility of the kidney to endothelial insults.

Broadly speaking the haemolytic uraemic syndromes (HUS) can be divided into diarrhoea-associated (D+) and non-diarrhoeal forms.

The aetiology of D § HUS in North America and Europe is infection by verocytotoxin-producing Escherichia coli (VTEC) in at least 80% of cases, whereas in the Asian sub-continent it is commonly associated with Shigella dysenteriae. The exotoxins from these organisms are similar, suggesting that they have an important role in the pathogenesis of the syndrome. Human renal cortex bears receptors for these toxins. However, it has not been shown that the endothelial injury of D+ HUS is directly caused by the cytopathic effects of Shiga or verocytoxins (VT).

In both VTEC and Shigella related BUS there is growing evidence that neutrophils (N) play a role in the pathogenesis.

Following infection, there is a rise in peripheral blood N count in those patients who subsequently develop HUS, and the N count at the time of diagnosis correlates positively with adverse outcome. Moreover , in HUS patients plasma concentrations of elastase are higher than the expected from the neutrophil count alone and also correlate with poor prognosis. Elastase is an important neutrophil-derived proteinase which is released from the primary granules during polymorph activation at the same time as oxygen-derived free radicals. There is indirect evidence suggestive of tissue exposure to oxygen-derived free radicals in HUS. For example, erythrocyte membrane phospholipid concentrations are abnormal and there is depletion of arachidonic acid.

Plasma lipids have been shown to contain an increased proportion of the diene-conjugated form of linoleic acid, a marker of lipid per0xidatien. This would fit with the hypothesis that oxidative injury is induced by neutrophil activation, but does not constitute proof.

There are no known pathways by which the exotoxins VT or Shiga alone promote a neutrophil response or direct it against renal blood vessels. However, endotoxin (lipopolysaccharide, LPS) absorbed across damaged colonic mueosa could be responsible in a model resembling the generalised Schwartzman reaction. In such models either two separate, or a single continuous injection of LPS causes glomerular thrombosis in rabbits. The importance of neutrophils is shown by the observations that neutropenia induced by Busulphan prevents the reaction, and that transfer of activated neutrophils from a LPS treated animal can induce vascular lesions in a recipient.

LPS stimulates monocytes to release the cytokines Interleukin-1 and Tumour-Necrosis-Factor which in turn up-regulate adhesion molecule expression on endothelium.

It also causes "priming" of neutrophils to increase both their adhesiveness and respiratory burst. Neutrophils probably require a second signal to become activated and release their proteinases and oxygen radicals.

Potential stimulants include Platelet-Activating-Factor, the urinary excretion of which has recently been shown to be increased in D+ HUS. In vitro experiments which explore the role of neutrophils in inducing endothelial damage show that both elastase and oxidants are required together. This synergism is also essential for causing a reduction in glomerular filtration rate in an isolated perfused kidney model.

The LPS-neutrophil hypothesis for D+ HUS is attractive but incomplete. Although there is evidence of LPS exposure in children with Sbigella dyaenteriae, this has not been reported so far in VTEC induced disease. Moreover, D+ HUS differs significantly from endotoxic shock in which capillary damage is widely distributed. The propensity for renovascular damage needs explanation. A fruitful area for future research is likely to be the interaction between LPS-neutrophil pathways and endothelium which has been sublethally damaged by VT or Shiga exotoxins. C 44 S-5.0 GENETIC RENAL DISEASES Chairpersons: Marie-Claire Paris) and Clifford E. Kashtan (University of Minnesota, Minneapolis, MN) Inherited diseases of the kidney and urinary tract have fascinated pediatric nephrologists for many years, although with few exceptions, explanations of the pathogenesis of these disorders have eluded us. Recent advances in Jnoiecular genetic technology have made available new tools with which to investigate genetic renal diseases and, in some instances, important insights have already been achieved. In this symposium we will discuss four genetic renal diseases representing a broad spectrum of pathologic processes. We chose not to include cystic diseases of the kidney as they will be addressed in a state-of-theart lecture by Dr. Avner.

We will begin this morning's talks with Dr. Corrine Antignac of the H6pital Necker-Enfants Malades in Paris, who will discuss Alport syndrome and mutations in the gene COL4AS, which encodes the alpha 5 chain of type IV collagen. This gene was cloned in 1989 in the laboratory of Karl Tryggvason at the University of Oulu, and since then a variety of mutations in the gene have been identified in families with Alport syndrome. The discovery of the COL4A5 gene will enhance diagnosis and genetic counseling in families with hereditary nephritis. A challenge for the future will be to explain how defects in the alpha 5 chain of type IV collagen lead to kidney failure, sensorineural deafness, and the ocular abnormalities of Alport syndrome.

Dr. Antignac will be followed by Dr. Jerry Pe!fetier from McGiH University in Montreal. Dr. Pelletier will present results of his studies of the Wilms tumor suppressor gene, WT1, in patients with Denys-Drash syndrome, the triad of XY gonadal dysgenesis, Wilms tumor and renal failure due to diffuse mesangial sclerosis. The significance of Dr. Pelletier's work extends far beyond this clinical entity, as WT1 appears to play an important role in the normal developmen~ and matur~tior~ of the kidneys and gonads.

Our third speaker will be Dr. Nine Knoers of the University of Nijmegen in the Netherlands. Dr. Knoers' subject will be the pathogenesis of nephrogenic diabetes insipidus (NDI), as well as progress in the mapping and isolation of the NDI gene. Clearly an understanding of this disorder will contribute greatly to our comprehension of the processes of urinary concentration and dilution.

The final topic in this symposium will be primary hyperoxaluria, to be presented by the team of Dr. Jcn Scheinman of Duke University and Dr. Avi Katz from Jerusalem. They will discuss the pathogenesis of the disorder as well as therapeutic approaches. Oxalosis, the terminal manifestation of primary hyperoxaturia, should now be considered amenable to therapy, and in many cases should be a preventable condition.

We hope this symposium will excite and interest you and demonstrate the significant advances that have taken place in the area of genetic renal disease in recent years. Alport syndrome (AS) is an inherited disorder characterized by progressive hematuric nephritis with typical ultrastructural changes of the glomerular basement membrane (GBM) -such as combined thinning and thickening with splitting of the lamina densa -and sensorineural deafness. Ocular changes, lenticonus anterior and macular changes may be found. The association of AS with diffuse esophageal leiomyomatosis (DL) has been reported in a few cases. AS is a phenotypically heterogeneous disease, with two predominant clinica~ypes :juvenile-onset end stage ren~_l disease (ESRD), and adult-onset ESRD with or without deafness. An altered composition of the Alport GBM has been suspected based on the observation that Goodpasture autoantibodies fail to bind to Alport GBM, and that a minority of AS transplanted patients developped anti-GBM glomerulonephritis, with failure of these antibodies to bind to Alport GBM. The absence of ~3 and ~4 (IV) collagen chains from some AS GBM by immunohistochemical studies adds substantial evidence that AS is a type IV collagen disease. AS appears to be inherited as a dominant X-linked trait in most cases, as shown by pedigree analysis and linkage studies, the data of which enabled mapping the AS locus tO Xq 22. Recently, a gene (COL4AS) coding for a previously unknown basement membrane type IV collagen chain, has been cloned and mapped to Xq22, whereas genes coding for ~3 and c~4 chains were mapped to chromosome 2. COL4A5 structural defects found in 3 of 18 Utah kindreds identified COL4A5 as the relevant gene for X-linked AS. To date, 10 different deletions or major rearrangements of the COL4A5 gene have been reported by different groups and 18 others have been found in our laboratory by conventional Southern blotting using COL4A5 probes covering the whole cDNA. The deletion detection rate varies from 5%, to 16% in our series. in 2 instances, the COL4A5 gene is completely deleted. In others cases, the breakpoints of the deletions are either intra-or extragenic.Abnormal junction fragment allowing the detection of female carriers are present in ihalf cases. In addition, 10 single base mutations in various COL4A5 regions have been reported, identified by various techniques, either by Southern blotting when the mutation removes a restriction site, or by single strand conformation polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE) or direct sequencing. All deletions have been found in patients with juvenile onset AS, whereas point mutations could be associated with the different phenotypes -juvenile onset ESRD, adult onset ESRD with or without deafness -could be found in patients with point mutations. COL4A5 mutations have been described in 6 among 12 patients with post-transplant anti-GBM glomerulonephritis. They consisted in 2 complete deletions, 3 intragenic deletions involving the 3' part of COL4A5 and a point mutation in a splicing site. These mutations lead, at least, to the absence of the NC1 domain of the o~5(IV) chain bearing target epitopes of alloantibodies. These findings strongly suggest that such mutations could represent risk factors for the occurence of post-transplant anti-GBM giomerulonephritis. However, other factors than the genetic defect itself seem to intervene in determining this complication. We looked for COL4A5 mutations in 6 patients with the association of AS and DL. All of them have a deletion in the 5' part of the COL4A5 gene, extending beyond its 5' end for at least 700 bp. These findings demonstrate that the same gene (COL4A5) is involved in classical AS and in AS associated with DL and suggest that DL might be due to the alteration of a second gene involved in the smooth muscle cell proliferation and located upstream of the COL4A5 gene. The Wilms' tumor suppressor gene, WT1, residing at chromosome 1 lp13, has recently been cloned and characterized. The predicted WT1 polypetide shows several features characteristic of transcription factors (nuclear localization, four contiguous Cys2-His2 zinc finger domains, and an amino terminus rich in proline and glutamine residues). This gene is highly expressed in the developing glomerular epithelium, fetal gonads, as well as the Sertoli celis of the testis and granulosa cells of the ovaries. Recent results have implicated WT1 in some cases of hereditary Wilms' tumor as well as in development of the genital system.

Denys-Drash syndrome is a rare human condition in which severe urogenital abberations result in renal failure, intersex disorders, and Wilms' tumor. To investigate the possible role of WT1 in the etiology of Denys-Drash syndrome, we have analyzed the coding exons of WT1 for possible germline mutations. In fourteen independent cases of Denys-Drash syndrome, point mutations within the DNA binding domain of one WT1 gene copy were identified by single-strand conformational polymorphism (SSCP). These mutations directly affect DNA sequence recognition. In three families analyzed, the mutations were shown to arise de novo. Four Wilms' tumors and one granulosa cell tumor from individuals with Denys-Drash syndrome demonstrated reduction to homozygosity for the mutated WT1 Mlele. In one case of Denys-Drash, a mutation within an intron was detected which affected splicing of the WT1 mRNA. These results indicate that mutations within the WT1 gene are responsible for the constellation of phenotypes associated with Denys-Drash syndrome. In addition, they implicate a key role for the WT1 gene product in development of the urogenital system. C 45 S-5.3 PRIMARY HYPEROXALURIA Jon L Scheinman. Avi Ka~z. Duke U. Durham NC, and Jerusalem Primary hyperoxaluria is caused by metabolic errors in amino acid matabolism: Type I (PH1, AGT deficiency) in liver trans-amination of glyoxylate, causing buildup of glycollic acid and oxalate. The defect may be absolute, partial, or due to misplaced enzyme. Type II results from absent conversion of hydroxypyruvate to D-glycerate, increasing L-glycerate through LDH and NADH, shifting the NAD:NADH balance, finally increasing oxidation of glyoxylate to oxalate. Most important for nephrolithiasis is the total oxalate excretion and intratubular urine supersaturation. In view of the multiple possible pathways for glycollate and glyoxylate metabolism, and the uncertain effect of pyridoxine (B6) on these pathways, a simple enzymatic diagnosis may inadequate to dictate therapy. Even continued massive hyperoxaluria can be tolerated when GFR is high, urine dilute, and urine calcium low. This strategy has allowed prevention of renal failure and successful LRD transplantation, with agressive dialysis to avert early crystallization. Even in infants and children presenting with nephrocalcinosis and ESRD, a 50% long-term success has continued, with mortality usually due to denial of early re-transplant. Older patients, treated soon after the onset of-ESRD, have even better results.

In PH1, with the primary defect in liver, liver transplantation offers the promise of cure, at the cost of 20% 1-year mortality in the most experienced series, far greater in occasional centers. Even in this most successful center, only 65% of these patients had good renal function at 1 year. Therefore, until "cure" is more reliable, it is advantageous to select the patient who might benefit most from this risk. Neither presentation nor hepatic AGT analysis predicts certain failure of kidney transplant, with successful kidney transplants performed in children with severe presentation, absent AGT, and even after failure of a first graft. In designing a patient-oriented strategy, there are crucial questions to be answered:

-Does the patient have an error in oxalate metabolism? If urinary excretion of oxalate and glycollate are not definitive, as in ESRD, plasma glycollate may allow diagnosis of PHI. Liver biopsy is innocuous enough to justify a definitive diagnosis.

-Can oxalate generation be altered? B6-sensitivity may be considerably delayed, and require large doses. Several patients have been found only long after successful renal transplantation to have only moderate oxalate excretion. We are concerned that a patient may receive a liver/kidney transplant for a process that may be essentially resolved. Plasma oxalate, related to creatinine, before and after institution of B6, may reveal pyridoxine response. The current plasma oxalate methods are only questionably satisfactory. If some patients have such massive oxalate generation that kidney transplant is doomed, plasma oxalate/creatinine ratio may allow that prediction. After renal transplantation, periodic urinary oxalate determination is appropriate, as marked changes can occur, which reflect the risk of nephrocalcinosis.

-Is there a mass of deposited oxalate that can leave tissue stores and add to endogenous production, to present an insurmountable load to the new kidney?. Visible deposits may be obvious. Length of time on dialysis (especially CAPD) makes that risk certain. Bone/bone marrow biopsy may prove predictive. If agressive (almost daily) hemodialysis cannot be maintained until transplant, this situation may only have potential success with combined liver/kidney transplant. In the patient with a failing first kidney transplant, another is feasible if ESRD and body oxalate deposition are not allowed to progress. Results of kidney transplantation will continue to improve if it is performed prior to ESRD, and if agressive removal (hydration, dialysis) of oxalate is performed during allograft dysfunction.

-Is it possible to plan a (living related or unrelated) kidney transplant, thus carying out the exacting preparation and intertransplant protocol? We have little evidence of successful cadaver kidney transplants performed after dialysis is required, so that the risk liver/kidney transpl~t m.ay be reasonable.

-Can the pauent mmntam a rigid program of massive hydration and medications to inhibit CaOxalate supersaturation? The patient with relatively routine transplant management might preserve a liver/kidney transplant. For PH1 success in kidney transplant, some patients cannot achieve the degree of compliance required, that skirts the edge of hypocalcemia, and allows no lapses. They may be better served by the more agressive approach.

The lack of correlation between the course of the original disease, the results of transplantation, and the degree of enzymatic deficiency, all support the involvement of other genetic and environmental factors. Areas to explore include the activity of other enzymes affecting oxalate synthesis, variations in CaOxalate supersaturation, abnormalities in intestinal and renal oxalate transport, and nutritional or climatic factors. is that which primarily addresses the patient, not only the enzymatic machinery. Nehrogenic diabetes insipidus (NDI) is a rare inherited disorder characterized by insensitivity of the distal nephron to the antidiuretic effect of vasopressin. AS a consequence, the kidney loses its ability to concentrate urine. The clinical features of the disease are polyuria, polydipsia, life-threatening dehydration, fever, anorexia and failure to thrive. Without treatment severe dehydration of the brain may lead to mental retardation. In most cases, NDI is inherited in an X-linked fashion. Linkage analyses have shown that the NDI locus is located in the subtelomeric region of the X chromosome long arm, at band Xq28. Although the molecular pathogenesis Of X-linked NDI is unknown at present, the renal vasopressin V2 receptor has been considered as the possible site of the underlying defect. This V2 receptor is bound to the adenylate cyclase complex resulting in an increase of cyclic AMP and can thus be distinguished from the vasopressin type 1 receptor, which is coupled to a phosphoinositide specific phospolipase and intracellular Ca 2+ mobilization. There is convincing evidence that the vasopressin type 1 receptor is intact in NDI. Firstly, NDI patients show normal vasoconstrictive responses after administration of vasopressin. Secondly, binding of vasopressin to type 1 receptors on thrombocytes isolated from NDI patients appeared to be normal; that is, binding characteristics (binding affinity and maximum binding capacity) in NDI patients were identical to those in normal control individuals. To test the hypothesis that the defect in NDI might be at the level of the vasopressin type 2 receptor, V2 receptor activity has been examined in somatic cell hybrid cell lines,, using a functional assay based on the increase of cAMP after addition of Arg-vasopressin to the medium. A hamster/human hybrid cell line, which contained as the sole human component the Xqter region, displayed Vz receptor activity while the hamster control cell line did not, indicating that a functional gene for the Vz receptor is located in the Xqter region. This observation has led us to a strategy to clone the NDI gene by analyzing cloned DNA fragments from Xqter for V2 receptor activity in a complementation assay system. This chromosomal region of interest, however, is still about 12 million base pairs long. By extending the linkage analysis in NDI families we were able to further refine the genetic localization of the NDI gene, thus reducing the region to be analyzed for V2 receptor activity with 75%. Also more somatic cell hybrids with different breakpoints in Xq28 were tested for V2 receptor activity. This has resulted in a further 50% reduction of the X-chromosomal region to be analyzed. Now about 1,5 million base pairs have to be screened for the V2 receptor geneo It is now straightforward to use yeast artificial chromosomes (I~ACs) located in the region of interest varying in length between 100.000 and 1.000.000 base pairs, for transfectien in a Vz receptor deficient cell line. The genetic localization of the NDI gene is up to now entirely compatible with the physical mapping of the V~ receptor gene. This strengthens the assumption that both genes are identical and lends further support to the NDI gene isolation strategy outlined here.

The efficacy and safety of ciclosporin in idiopathic nephrotic syndrome of childhood. B. von Graffenried, M.D., Sandoz Pharma Ltd., . Basle, Switzerland i. Patients 195 children (~ 15 y.) were treated with ciclosporin (Sandimmun | , SIM) for inducing remission of idiopathic nephrotic syndrome and/or for maintaining steroid-induced remission. 113 patients had minimal change nephropathy, M~C (mean age 8.4 y.; 83m/30f; mean disease duration 4.4 y.; 24% steroidresistant, SR; 76% steroid-dependent, SD; 68% pretreated with cytostatic agents); 82 pat. had focal segmental glomerulosclerosis, FSGS (mean age 9.0 y.; 45m/37f; mean disease duration 3.1 y.; 77% SR -23% SD;

62% pretreated with cytostatic agents). In total, 90 pat. were steroid-resistant, SR, and 104 pat. were steroid-dependent, SD (in 1 pat. steroidstatus was unknown). 2. Induction of remission with SIM (n = 127) In SD-patients (n = 37), complete remissions (CR) were achieved in 84% and partial remissions (PR) in 8%. In SR-pat. treated with SIM alone (n = 46), CR occurred in 9% and PR in 17%. In SR patients treated with SIM + pzednisone (mean dose 12.6 mg/d, n = 44), responder rate was clearly higher (CR 25%, PR 27%). Results were similar between patients pretreated or not pretreated with cytostatic agents. Time until remission was 1 month (median). Mean SIM-doses 6.0 mg/kg/d. There were no relevant differences in SIM dosages or SIM blood levels between responders and failures. Patients who went into complete remission had full normalization of proteinuria, serum albumin and cholesterol and disappearance of oedema. Relapse rate and time until relapse varied with the type of treatment strategy chosen. CR was maintained for 6 months in 67% if SIM was continued, but in only 20% after abrupt stop of therapy. There were no relevant differences in relapse rate between MCNand FSGS -, and between SR -and SD -patients.

3. Maintenance of steroid-induced remissions (n= 92) After induction of complete remission with steroids in SD patients, SIM (5.3 mg/kg/d) was able to maintain remission for at least 1 month after withdrawal of steroids in 84% (75% complete withdrawal, 9% reduction to ~ i0 mg alternate day prednisone). Steroid-free remissions were maintained for 6 months in 72% if SIM was continued, but in only 20% after stop of SIM.

Catch-up growth was observed upon steroid withdrawal. 4. Tolerability/safety SIM was discontinued because of adverse events in i0 patients (5.1%), mostly because of renal dysfunction (8 pat.) . In most cases, these patients already had abnormal renal function at baseline and were treatment failures. In MCN, mean creatinine at end of SIM-therapy was 6.7% above baseline, and 11% had increases above 50% over baseline. These changes were reversible after stop of SIM. In FSGS, mean % increase of creatinine over baseline was 16% at end of therapy, and increases above 50% over baseline were seen in 24%. After stopping SIM, reversibility was achieved with the exception of 3 SR-patients in whom end-stage renal failure developped. In renal biopsies, moderate interstitial fibrosis without arteriolopathy was seen in 3/34 patients with MCN. In 2/12 patients with FSGS, SIM-nephropathy was suspected. The most frequent adverse events were hypertrichosis (27%), gingival hyperplasia (18%) and hypertension (10%). Incidence and severity of infections were not a problem. No malignancy occurred. 5. Conclusion SIM is very effective in inducing remission and maintaining these despite withdrawal of steroids in steroid-dependent nephrotic syndrome, but is less effective in steroid-resistant forms. In the latter, efficacy is improved when combining SIM with low dose steroids. SIM ~an be recommended in children not responding to conventional therapy or in whom such treatment, although effective, has induced relevant side effects. Steroid resistant INS carries a poor prognosis since, after a follow-up of 10 years, about half of the patients progress to endstage renal failure. Immunosuppressive agents may be efficient but there is no study showing a clear-cut beneficial effect of alkylating agents as the remission rate after such treatment is close to the rate of spontaneous remission. Recently, CsA has been administrated to steroid resistant patients with conflicting results. Retrospective cumu]ative analysis shows that the combination of CsA with prednisone, even at low doses, appears to improve the chance of remission from 15 to 25% of cases.

In March 1988, the. French Society of Pediatric Nephrology started an open study on the effects of CsA in association with prednisone in children with steroid resistant INS. Sixty-one children, 29 girls and 32 boys, aged 1 month to 14 years 6 months at the onset of nephrotic syndrome,were included in the study. They all had failed to respond to daily prednisone therapy 60 mg/m 2 for 1 month followed by three methylprednisolone pulses 1 g/l,73m 2 every other day. All patients (pts) had a creatinine clearance higher than 50 ml/mn/l,73 m 2 and had had the disease for more than 2 years. Eight pts had previously received chlorambucil, 4 pts cyclophosphamide et 1 pt mechloretamine without beneficial effect. Renal biopsy had shown minimal change disease (MCD) in 41 pts and focal and segmental glomerular sclerosis (FSGS) in 19. CsA, 150-200 mg/m 2, was given in combination with prednisone, 30 mg/m 2, for 1 month and with alternate day prednisone, 30 mg/m 2, thereafter for 5 months. Prednisone was then gradually decreased and discontinued at the end of the 9th month and CsA was then similarly decreased and discontinued after one year.

Twenty-seven children entered into complete remission, 14 of them within the first month of therapy, 4 within the second month, 3 within the third month and the remaining 6 between the fourth and sixth months. One pt relapsed when prednisone was tapered to alternate day, 10 relapsed while receiving CsA alone 25 to 185 mg/m2/day and 2 relapsed after CsA had been withdrawn. At latest examination, 5 pts who had relapsed became steroid sensitive, 20 pts were in complete remiss.~on including 9 who were still receiving CsA and 11 pts in whom CsA had been withdrawn, one non compliant pt was in partial remission and only one pt, who had relapsed, was nephrotic.

Four children were in partial remission after 6 months of therapy. One pt was still receiving CsA and in partial remission at lastest examination. CsA was withdrawn after 10 to 13 months in the remaining 3 pts. Two of them were in partial remission 2 to 3 years after discontinuation of CsA while the third pt had progressed to renal failure.

Thirty children failed to respond to the treatment. Four pts experienced a decrease of renal function while receiving CsA. Three of them further deteriorated despite CsA withdrawal. At latest follow-up, 10 to 48 months after initiation of therapy, one pt was in complete remission following a course of chlorambucil, 3 pts were in partial remission, 13 pts had a persistent nephrotic syndrome and 13 pts had progressed to renal failure including 8 with terminal renal failure. Three of these pts have been successfully transplanted.

Among the side effects of treatment, 20 pts developed hypertension, 27 hypertrichosis, 15 gum hypertrophy, 9 gastrointestinal manifestations, 3 headhaches and 1 gynecomastia.

The response to CsA and prednisone was not related with the histological findings since, among the 27 pts who responded to the treatment, 20 had MCD and 7 FSGS, whereas among the 30 pts who failed to respond, 20 had MCD and 10 had FSGS.

In conclusion, CsA in association with prednisone induced a complete remission in 44% of 61 children with steroid resistant INS. Remission was observed in 48% of pts with MCD and 37% of pts with FSGS. Among the pts who responded to the treatment, 18% became steroid sensitive, 33% were still in remission 5 months to 3 years after cessation of treatment and none had progressed to renal failure. Conversely, 43% of the pts who failed to respond to CsA progressed to renal failure. In recent years a role has emerged for cyclosporine-A in the treatment of nephrotic syndrome. As yet, the precise mode of action of cyclosporine in this disorder is the subject of vivid debate. Cyclospodne is a potent suppressor of Tcell derived lymphokines which could play a role in the permeability of the glomerular basement membrane under pathological conditions. On the other hand, CsA is known to exert distinct effects on renal perfusion and filtration through constriction of the afferent glomerular arteriole which could contribute to cyclosporine's antiproteinuric action by reducing net ultraflltration pressure.

We studied renal hemodynamics and glomerular basement membrane permeability in 26 patients with nephrotic syndrome (minimal change disease (MCD,n=8); membranous glomerulopathy (MG,n=8); membranoproliferative glomerulonephritis (MPGN,n = 5) and focal segmental glomerulosclerosis (FSGS,n = 5). Cyclosporine was taken at meal-times in two separate doses (6 mg/kg per day). Subsequent maintenance CsA therapy was adjusted to achieve trough levels of immunoassayable CsA in plasma around 50 ng/ml. Each patient was studied twice, at the start of the trial and following three months of treatment with CsA. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined by a constant infusion technique, by measuring the renal clearances of ~l-iothalamate and ~3~l-orthoiodohippurate (Amersham, UK) respectively. Basement membrane permeability was measured by means of the fractional clearance of polydisperse neutral dextrans. In the urine and plasma samples used for the measurement of dextrans we also measured albumin, IgG and IgG 4 concentrations. To analyze the size selective properties of the glomerular barrier we used a heteroporous model of the glomerular capillary wall as described by Deen. In this model the major portion of the capillary wall is perforated by restrictive cylindrical pores of identical radius (re). In addition this model assumes a parallel "shunt pathway" that does not discriminate on the basis of dextran size and through which a small fraction of the filtrate volume (~) passes. The membrane barrier to dextrans is fully characterized by r o, to,, and Kf, where K~ is the product of effective hydraulic permeability and glomerular capillary surface area.

In our patients with MCD the antiproteinuric effects of low,lose c~;closporine were most striking as a complete remission was obtained in five out of eight patients. Before cyclosporine, in the baseline untreated state the proteinuria was highly selective. The fractional clearance of large dextrans with radii > 40 A was comparable to that in normals. In contrast, the sieving of small dextrans was hindered. We could explain the abnormal sieving of small dextrans in this condition by a reduction in Kf. The marked reduction in protein excretion observed in MCD after cyclosporine was due to restoration of charge selective, of the giomerular basement membrane as measured by IgG/IgG 4 clearances. The hampered sieving of small dextrans was improved by cyclospodne although values did not reach the level observed in normal controls. Calculation of membrane parameters indicated that the raised fractional clearance of small dextrans can be accounted for by a rise of Kf. Such effects are difficult to reconcile with a vasoconstrictory effect of cyclosporine.

Cyclosporine also had a pronounced effect on proteinuria in patients with MG N. However its mode of action on the diseased glomerular bai'rier was different from that in minimal change disease. Before cyclosporine, in the untreated state, proteinuria was non-selective and the clearance of iothalamate, the fractional clearance of uncharged dextrans with a radius between 28-38 A and filtration fraction were depressed significantly below values in our healthy volunteers. In contrast, the passage of dextrans with radius > 54 A was increased. This can be explained by a loss of intrinsic ultrafiltration capacity (depressed Kf) and decreased barrier size selectivity. We calculated Kf to be depressed threefold and the fraction of filtrate permeating the shunt pathway (~o) to be increased fivefold. In contrast to the effects of cyclosporine on charqe selectivity in patients with minimal change disease, the antiproteinuric action of cyclosporine in membranous glomerulopathy was the result of an increase in size selectivity of the glomerular filtration barrier. Blood pressure and GFR did not change significantly, although ERPF fell markedly. The fractional clearance of dextrans measuring 28-32 A rose and that of large dextrans (50-58 A) fell. Our computations revealed that the changes in glomerular sieving induced by CsA can be accounted for by a rise in K~ and a pronounced diminution of filtrate passing through the "shunt" pathway ~o.

In FSGS and MPGN, proteinuria was non-selective from the onset and remained so after treatment. No effect of cyclosporine on proteinuria was observed in these patients. Following CsA, renal hemodynamics were severely disturbed in FSGS and MPGN patients with both GFR and ERPF dropping markedly and renal vascular resistance rising. In all patients in which CsA was discontinued proteinuria returned promptly. At present it is unclear wether a lasting remission can be obtained with longer treatment and prolonged treatment with low doses of CsA (2 to 4 mg/kg/day) is required to maintain remission. It remains to be demonstrated that these lower doses are free of long-term nephrotoxic side effects as evident morphological changes were observed at doses as low as 5 mg/kg/day. Therefore caution is in order for the long-term use of CsA in diseases with a relatively benign course, such as MCD and MG.

We conclude that in membranous glomerulopathy cyclosporine exerts its effects on proteinuria mainly through a change in the permeability characteristics of the glomerular basement membrane resulting in a decrease in shunt-flow, despite increased filtration fraction. In minimal change disease cyclosporine decreases proteinuria through an increased charge selectivity and appears to increase Kf. The massive proteinuria often associated with this and other glomerular lesions has been shown to be deleterious to renal function and increase the progression to end stage renal disease (ESRD).

The pathogenesis of the proteinuria appears to be immune mediated. Elevated levels of the cytokine, interleukin-2 (11-2) have been demonstrated in patients with the nephrotic syndrome.

The addition of cyclosporine in nephrotic patients has correlated wfth a decrease in 11-2 levels and a clinical remission.

Although cyclosporine has been effective in reducing the proteinuria of the nephrotic syndrome, the benefits are not observed universally.

Children are known to metabolize cyclosporine more rapidly and therefore, they require more frequent and higher doses than the standard doses used in adults (5mg/kg/d). Thus, careful monitoring of blood levels and titrating the cyclosporine dose to maintain a steady level may prove helpful in nephrotic patients.

Additionally, adjusting the CSA dose to the in vitro immunoresponsiveness of a patient has proven beneficial in an adult transplant population.

Immune monitoring may be applied to the nephrotic population. However, caution should be exercised when using higher cyclosporine doses in patients with lower serum cholesterol levels because of the risks of inducing nephrotoxicity. ~le have shown that severe hypercholesterolemia has been correlated with a poor prognosis in a subset of children with FSGS. We have also reported that patients with nephrotic range proteinuria who did not respond to standard doses of cycl osporine demonstrated severe hypercholesterolemia.

The distribution of cyclosporine in the blood is dependent upon the various lipoproteins to which it is bound.

It has been suggested that the entry of cyclosporine into the target cell is linked with the low density lipoprotein receptor.

The tissue distribution of both cyclosporine and the LDL receptor are similar.

Thus, hyperlipidemia prevents cyclosporine from reaching its target tissue.

Data will be presented on how this inhibition can be overcome by titrating the cyclosporine dose with serum cholesterol level in a nephrotic population without inducing nephrotoxicity.

Since the toxicity of cyclosporine is dose related an alternative approach will -be necessary in patients with lower cholesterol levels. Another strategy to improve the efficacy of cyclosporine would be to utilize combination drug therapy.

Rapamycin has been shown in vitro to synergize with cyclosporine.

In vivo use of nifedipine in transplanted patients has been shown to improve graft survival possibly by decreasing cyclosporine-induced perfusion injury.

Thus, combination therapy may improve cyclosporine efficacy and reduce the risks of nephrotoxicity. 

For years now, sonography plays a major role among the imaging modalities of the urinary tract (UT) of children. Radiologists and pediatricians appreciate this procedure because it is easy to perform and a non irradiating technique. The fields of applications of ultrasound in pediatric nephro-urology are wide (table i). Antenatal ultrasound has become the most frequent way of discovering renal abnormalities. This has brought many changes in the work-up and management of nephro-uropathies. At birth, the anomaly has first to be confirmed and postnatal ultrasound is the first procedure to be performed. Its result decides whether further investigations are necessary. Ultrasound has also become the main (and usually the only) screening method of nephro-uropathies in patients ar risk; these nephro-uropathies include malformations possibly associated to other anomalies (i.e. vertebral malformations), tumors in patients at risk of developping benign (i.e. angiomyolipoma in Tuberous Sclerosis) or malignant tumors (i.e. gongenital aniridia and Wilm's tumor), or patients with familial history of polycystic kidney disease. Sonography is usually the first procedure performed in the work-up of urinary tract infection. It is the best method to show underlying malformations, parenchymal thickness and thickening of pelvic and ureteral wall in cases of pyelitis or ureteritis. Yet, ultrasound underestimates the presence of vesico-ureteral reflux and the number of renal scars and therefor complementaries imaging procedures are mandatory (cystogram, isotopes, .... ). Once the work-up has been completed and treatment established, ultrasound is helpful in assessing renal growth. As mentionned above, US is used in the work-up of abdominal and especially renal tumors. It helps to characterize the type of tumor, to detect the presence of adenopathies and to evaluate vascular involvment thanks to color doppler imaging. In case of large or/and invading tumors, other modalities (CT, IRM) will be necessary to evaluate tumoral extent. Sonography helps to determine the origin of hematuria and is a good method to demonstrate urolithiasis and lithiasis-related disease. In case of acute renal failure US differentiates between parenchymal and collecting system diseases. Associated to color doppler imaging, it verifies the patency of renal vessels. US can be used to follow chronic renal disease, be it related to reflux nephropathy or to congenital disease. After renal graft, for years now, US has been used to evaluate the graft and related diseases. Finally, US is the method of choice to follow post-operative or endoscopic procedures in order and to detect complications.

The role of US is continuously extending and color doppler imaging has added new applications. As for other radio logical procedures, there are now typical sonographic appearances that by themselves lead to specific diagnosis (i.e. nephrocalcinosis). The role of US is further imporLant because clinicians rely on its to decide whether further examinations are necessary. Therefor, the examinator should be well trained and experienced. Good knowledge of normal, atypical and abnormal characteristics of the kidney sonography is necessary in order to obtain best results.

In conclusion, US has the central role in the work-up of nephro-uropathies. Constant improvements in its accuracy are obtained thanks to growing experience and newer equipment. S-7,2

Voiding eystourethrography (VCUG) is one of the important imaging procedures for evaluation of the urinary tract in children. Its main indications are urinary tract hffectlon and clarification of an anomaly of the urinary tract on fetal sereanhag in the neonate. VCUG is, in these cases, often the first imaging examination. The most important pathological findings include veslco-ureteral reflux (VUR) and bladder outlet obstruction. VUR is present in about 35-40% of ehi/dren with infection, and is one of the findings which will determine whether treatment will be medical or surgical. Bladder outflow obstruction, mahfly posterior ureteral valves in the male and extopic ureterocele in both sexes has its characteristic findings on the VCUG and is an indication for surgery. We perform additional imaging procedures such as urography, ultrasonography and nuclear scanning of the kidneys as deemed necessary according to an algorithm developed in oar hospital.

To conclude: The VCUG is an indispensable examination in the evaluation of the urinary tract in children. The degree of reflux when present and the exquisite anatomical details of congenital anomalies of the lower urinary tract can best be determined by this method. views of the kidneys should always be obtained. The addition of the oblique views increases the sensitivity in detecting renal abnormalities (59 to 83%).

-Results can be expressed as relative or absolute function. The absolute function is more adequate than the relative one to follow individual renal function in progressive diseases. In order to get reliable absolute values, functional studies must be undertaken 6 to 8 hours after the injection of the radiopharmaceutical.

FOR DMSA SCANNING -DMSA scanningis indicated for: (1) diagnosis end follow-up of patients with reflux nephropathy (RN);

(2) diagnosis of absent, small and/or ectopic kidneys;

(3) diagnosis of an occult duplex kidney; (4) diagnosis of a normal kidney in a child with urinary tract infec tion; (5) The ability to define the entire retroperitoneum is a huge advantage for C.T.

The three components of the retro-peritoneum are (1) the anterior pararenal space, As early as the 1920s, investigators learned that high protein diets fed experimental animals resulted in proteJnuria and renal disease. In the early 1980s, a role for dietary protein restriction in delayir~g the deterioration of renal function was suggested by Brenner and his colleagues. In animal models of progressive renal disease, the important glomerular change that leads to loss of renal function is glomerular sclerosis. The underlying mechanisms that result in glomerular sclerosis include hemodynamic changes in the glomerulus, increased glomeru~ar metabolism, local hypercoagulability, mesangial macromolecular deposition, and hyperlipidemia, in a model proposed by Fogo and Ichikawa, all the factors above, either individually or in concert with others, stimulate the production/release of glomerular growth promoters, which in turn induce glomerular hypertrophy and mesangial matrix production and accumulation causing glomerular sclerosis. Preliminary evidence is now accumulating that dietary protein restriction may indeed alter the production and/or release of locally derived growth factors. Systemic hypertension and increased intraglomerular capillary pressure have been shown to result in progressive glomerular damage and glomerulosclerosis. Studies have shown that dietary protein restriction results in a fall in glomerular filtration rate and a reduction in intraglomerular capillary pressure. This, too, could have a salutary effect on progression of renal disease. The mechanism by which dietary protein could influence glomerular capillary pressure is unproven, Tubulointerstitial injury has been proposed as a mechanism leading to progressive renal injury. This m~y be mediated through increased oxygen consumption by remnant nephrons, thereby increasing the susceptibility of remnant tissue to oxidant injury. Increased ammonia production of remnant nephrons has been associated with complement activation and interstitial inflammation leading to progressive injury. Here too the mechanism(s) by which protein restriction could alter tubulointerstitial injury is(are) unknown.

There is substantial animal model and human data to suggest that dietary protein restriction could have a benefit in slowing the progression of renal disease and retarding the development of glomerular sclerosis. The precise mechanism(s) is still a matter of debate and is under intense study. The alternative is to use patients as their own controls, which raises the obvious question of improved overall management and observer bias towads the study, and changes in pubertal status must be recognised.

Further con]olicating factors in either form of trial are differences in energy intake, parathyroid hormone (PTH) levels, degree of protein restriction and the use or non-use of the essential amino acids and histidine or their keto analogues.

It is also critical to assess the value of control of salt depletion and acidosis as discussed elsewhere in this symposium.

Within our own population, we chose a group of ten children with GFR less than 50~ and raised PTH levels who had been for at least two years on a controlled protein and phosphorus diet, appropriate salt and bicarbonate, vitamin D and energy intake aimed at least at 100~ of recorrmended daily allowance (RDA).

They were corrmenced on a strict low protein, low phosphate diet with added keto acid analogues.

Thus, the only dietary variables in this study were the amount and type 1 of protein and phosphate intake.

As previously reported ", during a three year period they maintained good compliance, normalised intact PTH levels, improved biochemistry, improved cholesterol and triglyceride levels, growth, bone disease and had a reduced rate of fall of GFR. Seven of these children have been maintained for a further period of t~ years on this diet and have maintained these improvements.

In view of our own observation and on assessment of other work, we believe there are substantial benefits in a diet based on low protein and phosphate intake. An obvious question to ask is whether early dietary intervention is important.

Our policy is to divide children with renal insufficiency into three groups: A -GFR greater than 66~, iess than 100~, B -GFR 33~ to 66~ and C -GFR less than 33~.

Group A is advised to avoid foods high in protein and phosphate and group B advised to take a diet with substantial reduction in protein and phosphate with added vitamin D. Group C patients are placed on the strict low protein/ phosphate diet described above.

We have observed that infants with significant chronic renal failure with early strict dietary intervention grow and maintain GFR much better than historical controls with less dietary intervention.

We believe a randomised controlled study in the infant age group to study the effects of a low protein diet is desirable, provided that phosphate is controlled and PTH noPrnalised in both the study and control population. After a run-in period of 6 months 203 children were stratified according to their renal disease and progression of disease during the run-in period and randomized for a low protein intake amounting to the WHO safe levels for age (0.8l.lg/kg/day) or free protein intake. Protein and energy intake were calculated from dietary diaries (at least 4/year: weighing method). Additionally, protein-intake was estimated from urea-excretion. 145 children finished their second year after randomization, i00 were male and 45 female. Mean age at randomization was 10.6 • 4.4 years and mean GFR 35.6 • 14.5 ml/min/l.73m 2. Their renal diseases were: glomerulopathy n=24, uropathy and hypo/dysplasia n=91, hereditary and congenital diseases n=28 and cystinosis n=2. Patients with a loss of GFR > l.Sml during the run-in period were stratified as "progressive' diseases and patients with a loss of GFR < 1.5ml were called "nonprogressive' diseases. Children with 'progressive' as compared to children with 'non-progressive' diseases differed significantly at start concerning age (11.8 vs. 9.4 years), GFR (31.0• vs. 40.4• ml/min/l.73m 2) and the incidence of adequately treated hypertension (20% vs. 9%). There was no correlation between GFR at start and loss of GFR during the run-in period or during the study period. The percentage of patients needing renal replacement therapy during the first two years after randomization was 23% in children with 'progressive' diseases and 1.4% in children with 'non-progressive" diseases. Stratification according to the progression of disease during the runin period eliminated the effect of stratification for renal diseases. Therefore, patients were analysed in groups according to progression rate and randomization only ('progressive' diet n=37 vs. control n=37 and 'non-progressive' diet n=32 vs. control n=39).

Mean protein intake of the diet group figured at 120• of the recommendations vs. 184• in the control group. Energy intake was equal in both groups (diet: 84• control: 90• Two third of patients randomized for the diet group demonstrated an excellent compliance. At randomization SDS for height for chronological age was -0.94• and body weight figured at 103.8• of ideal body weight per height. Lowering of protein intake with adequate energy intake did not show any unfavourable effect on growth and weight gain. The loss of GFR/2years was not significantly different in the diet group as compared to the control group ('progressive' diseases: -10. 3 The effect of low protei n diets to slow progression of renal disease in rats with reduced renal function has been unequivocally established~ It has been equivocally demonstrated~in adult patients with reduced renal function, using the method of meta analysis applied to six controlled clinical trials~ The end point used for the analysis was "renal death"; there has not been an agreed upon method for measuring progression~ Studies that evaluate low protein diet therapy in children with reduced. renal function are too few to dra~ any conclusions from analyses limited to these results~ However, ~uidelines for treating children can be developed from the total experience of diet therapy~ A low bat adequate protein diet for normal children and adults is one that provides adequate calories and has a protein:energy (P:E) ratio of 8% (FAO/ WHO/UNU, 1985)~ This is well below the P:E ratio (~15%) of the diet of many individuals in western cultures in which animal protein and phosphorus are abundant~ The recommendations exceed the P:E ratio (4-6%) of many diets proposed as treatment for patients with reduced renal function~ The trials analyzed by meta analysis compared diets at or below recommendation with diets above recommendations (10-12% P:E ratios)~ There is little evidence that diets below the recommended level for normal are more effective than diets meeting, "but not exceeding, the recommended levels and some question as to whether they are safe~ There is no evidence that diets with higher P:E ratios have any advantage and they may accelerate progression, either because of their protein, phospherus, and/or high saturated fat eontent, A safe recommendation is to prescribe a diet that meets, but does not significantly exceed, the recommendations for normal and to monitor the patient's SUN/SCr ratio for shifts in dietary protein~ Close dietary monitoring usually improves control of blood pressure and of hyperparathyroidism and these measures appear to slow progression independent of dietary protein intake~ Measuring progression in children has proved difficulto We have validated a method that is accurate and practical for measuring OFR serially in adults and children to quantify the rate of progression (AGFR/time)o This should facilitate evaluating proposed therapies that might slow progression in patients using clinical trial methodology~ Dietary protein prescriptions that are below recommended levels (less than 8% P:E ratio) require close monitoring for patient adherence and for evidence of undernutrition~ These prescriptions are difficult for patients to follow and expensive to monitor~ Evidence ti]aL such diets are safe and effective should be convincing before such therapies are used for general clinical practice~ S-8.5

The Effect of Acidosis, Salt and Water on Growth and Nutrition in Children with Chronic Renal Failure Steven J~ Wassner, Department of Pediatrics, The Penn State University Children's Hospital, Hershey, PA, U~S~A~ In addition to decreased glomerular function, abnormalities in tubular function are often important in the clinical care of infants and children with chronic renal disease~ Prominent~ among the tubular abnormalities is the development of acidosis due to both defective bicarbonate reabsorption and diminished hydrogen ion secretion. .Irrespective of GFR, acidosis has a specific effect upon protein metabolism and growth. Children with renal tubular acidosis and normal GFR's are growth retarded~ Growth.rates improve when they are treated with adequate amounts of sodium bicarbonate~ Zn both humans and laboratory animals, metabolic acidosis is associated with poor linear growth and weight gain, diminished nitrogen balance and increased rates of myofibrillar (muscle) protein degradation~ The change in nitrogen balance is due to an increase in protein degradation without any effect on protein synthesis. In rats and humans with chronic renal failure, repair of acidosis improves muscle protein degradation and nitrogen balance. These changes are due to altered levels of the enzyme branched-chain ketoacid decarboxylase (BCKD). The ketoacid of leucine, a-ketoisocaproate, inhibits protein degradation within muscle~ Acidosis stimulates the activity of BCKD, increasing the degradation of ketoleucine, thus lowering ketoleucine levels and stimulating muscle protein degrada-tion~ Both sodium and chloride depletion are associated with diminished growth and weight gain~ Salt loss may be unassociated with acidosis and these individuals often demonstrate volume contraction with the development of compensatory metabolic a!kalosis~ When sodium was removed from the parenteral alimentation mixtures administered to debilitated adults, nitrogen balance rapidly diminished~ Isolated chloride deficiency (the chloride depletion syndrome) was responsible for decreased growth in infants with normal renal funetion~ In our laboratory we have been able to demonstrate that either isolated sodium or chloride depletion lead to the same alterations in growth and protein turnover: decreased length and weight gain~ diminished nitrogen balance and within muscle, decreased protein synthesis rates and abnormal muscle RNA contenL Unlike the abnormalities seen in acidosis, the effect of either sodium or chloride deficiency are restricted to synthesis and muscle protein degradation rates are unaffeeted~ Protein turnover studies were performed in rats made either sodium or chloride deficient by feeding them synthetic, low-sodium or chloride formulas and distilled water. Control rats were supplemented with sodium chloride~ Sodium or chloride deficient animals demonstrated marked urinary conservation of the test compound while excretion of the counter ion was equal to that of the control group~ Protein turnover rates were determined using the epitrochlearis muscle preparation with and without the addition of insulin to the bathing media. Both sodium and chloride deficiency decreased protein synthesis by approximately 20%. Total muscle RNA content was decreased to an equivalent degree suggesting that sodium or chloride deficiency act by decreasing the capacity for protein synthesis. Other organs were also affected by salt depletion with liver weights being proportionally smaller while kidney weights were either normal or increased as a percentage of body weight~ When sodium depleted rats were salt repleted they rapidly regained weight and restored protein synthesis and RNA levels, but body length did not entirely catch up to that of the control animals. As yet, the cause of these alterations is unknown but the similarity between both sodium and chloride suggest that the defect may be better related to alteration in volume than in the specific electrolyte defic-iency~ Clinical correlation for both acidosis and salt depletion suggest that at least some of the growth abnormalities seen in renal failure can be related to abnormal acid-base and electrolyte metabolism~ This can be particularly important for infants with renal disease since they are fed defined diets with limited salt content. These infants are also most likely to demonstrate those structural anomalies associated with the development of acidosis and salt loss~ In these infants, when growth is subnormal the provision of additional dietary sodium chloride may lead to increased weight and length gain. Hyperparathyroidism remains one of the major causes of morbidity in children with renal failure. Pathologically increased secretion of parathyroid hormone (PTH) is the result of parathyroid gland hypertrophy and decreased sensitivity of parathyroid cells to extracellular calcium. The mechanism by which extracellular calcium suppresses PTH secretion is not clear. We and others have described a paradoxical relationship in parathyroid cells between calcium, the second messenger diacylglycerol, protein kinase C activity and PTH secretion. In bovine parathyroid cells the pharmacological activator of protein kinase C, phorbol myristate acetate (PMA) increases PTH secretion at high extracellular calcium where endogenous diacylglycerol (DG) formation is enhanced and PTH secretion is suppressed. Similarly, enhancement of endogenous parathyroid DG by inhibition of its metabolism with R59 022 resulted in inhibition of PTH secretion. To explore this relationship, we investigated the role of the endogenous sphingoid bases, sphingosine and sphinganine as potential inhibitory second messengers. These compounds are pharmacological inhibiters of protein kinase C and are formed in cells in the pathways of formation and degradation of sphingomyelin referred to as the sphingomyelin cycle. Our initial studies demonstrated that these sphingoid bases inhibited PTH secretion when added to bovine parathyroid cells. Moreover, sphinganine in bovine parathyroid cells was enhanced when parathyroid cells were incubated in high extracellular calcium. Ceramide, an intermediate compound in the formation of sphingosine from sphingomyelin similarly suppressed PTH secretion. Studies of the control of the enzyme sphingomyelinase in parathyroid cells demonstrated that DG but not PMA enhanced sphingomyelinase activity as demonstrated by ceramide formation. This differential effect of DG vs. PMA on ceramide formation was consistent with the lack of activation of protein kinase C and PTH secretion seen with increases in endogenous DG in bovine parathyroid cells. Ceramide formation was also enhanced at high extracellular calcium as compared to low extracellular calcium. In further studies, incubation of bovine parathyroid cells with HgC12 and p-hydroxymercuribenzoate, inhibitors of neutral sphingomyelinase blocked the ability of high extracellular calcium to inhibit PTH secretion and decreased parathyroid ceramide in cells incubated at high extracellular calcium. These effects were found to be reversible with incubation in fresh media without the inhibitors. We next studied the effect of inhibition of the glycosphingolipid biosynthetic pathway with D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), an inhibitor of the enzyme glucosylceramide synthase. Inhibition of this enzyme would be expected to increase ceramide and its products by blocking its metabolism to the glycosphingolipids. Our studies demonstrated that PDMP increases ceramide formation in bovine parathyroid cells and inhibits PTH secretion in a time and dose dependent manner. These results were also reversible after incubation overnight in fresh media. In summary, these studies are consistent with the hypothesis that parathyroid cells responffto high extracellular calcium with activation of a novel second messenger pathway, the sphingomyelin cycle. Inhibitory second messengers generated by this pathway contribute to the physiologic ability of high extracellular calcium to suppress PTH secretion and possibly explains the paradoxical relationship between DG formation and protein kinase C activity in this tissue. Secondary hyperparathyroidism (sHPT) in patients with renal failure remains a therapeutic challenge. Inappropriate renal synthesis of 1,25(OH)2D 3 is thought to play a major role in the genesis of renal sHPT. The primary aim of calcitriol treatment in uremic patients with sHPT is suppression of parathyroid overactivity. Parathyroid cells have receptors for 1,25(OH)2D 3 and 1,25(OH)2D 3 suppresses parathyroid cell activity through several mechanisms: (i) shifting the increased calcium set-point towards normal, (ii) reducing gene transcription for pre-pro-PTH and (iii) inhibition of parathyroid cell proliferation. Recently pulsatile administration of calcitriol by i.v. injection (Delmez, JCI 83, 1989) and-per os (Klaus et al., Lancet 337, 1991 , Tsukamoto et al., Nephron 57, 1992 has been shown to be effective for treatment of renal sHPT. The temporal relationship between oral administration of calcitriol and the nadir of 1,84iPTH concentration was examined in 9 adult patients and 6 children with renal failure of various degrees. A single oral pulse of calcitriol (2 ug) caused a delayed, but long lasting decrease of 1,84iFrH, which persists even after 1,25(OH)2D 3 plasma levels had returned to baseline (peak 1,25(OH)2D 3 plasma levels at 6-12h); 1,84iPTH levels were decreased significantly after 24h, the time to reach nadir (42-64% of baseline) ranging from 12-96h in adults as well as in children. Only a modest, but not statistically significant increase of serum calcium was noted; therefore it seems to be unlikely that the decrease in 1,84iPTH levels is explained by a rise in serum-calcium. These results are in agreement with experimental studies in uremic rats, in which a prolonged decrease in mRNA for pre-pro-PTH was noted after a bolus injection of calcitriol. When the same dose was administered either as a bolus or as a constant infusion by osmotic minipump, the former mode of administration was more efficacious (Reichel et ai., EDTA 1992). The increased effect of 1,84PTH suppression by 1,25(OH)2D 3 bolus might be related (i) to higher peak plasma concentration of 1,25(OH)2D 3 (associated with increased 1,25(OH)2D 3 receptor occupancy) and (ii) to upregulation of 1,25(OH)2D 3 receptor expression, as shown in growth plate chondrocytes in vitro (Klaus et al., IPNA 1992) . These experimental results confirm findings of our pilot study in 21 dialysis patients, who had elevated 1,84iPTH levels (12-200pmol/I, normal 1-6 pmol/1) despite daily oral calcitriol. Pulsatile oral calcitriol thrice weekly (0,5-3 g) decreased 1-84iFFH serum levels by 68.4% within 12 weeks. Hypercalcemic episodes, the most severe side effect of calcitriol therapy, can be decreased or even be avoided, when caletriol pulse therapy is discontinued, after FrH has fallen below a threshold level. In this context, it is of note, that after administration of 2ug calcitriol to healthy volunteers increased urinary elacium excretion rates return to pretreatment values within 2-3 days. After discontinuation of calcitriol, suppression of 1,84iPTH plasma levels persists for variable periods of time. We conclude, that pulsatile oral calcitriol is effective and safe for treatment of renal sHFr. The selection of optimal schedules with respect to time and dose of administration of calcitriol in the treatment of sHFr is currently under investigation.

Supported by Deutsche Forschungsgemeinschaft, grant K1 630/1-2. Hypercalcemia occurs frequently in solid-organ malignancies, and is termed humoral hypercalcemia of malignancy (HHM). 80% of the cases of HHM are from elaboration of a factor that resembles the actions of parathormone (PTH): hypercalcemia, hypophosphatemia with phosphaturia, and increased nephrogenous cAMP excretion. However, circulating levels of PTH and 1,25-dihydroxyvitamin~ are reduced. In 1987-88, three laboratories announced the isolation of the putative HHM factor, and recently, the gene structure has been determined. HHM factor is now called parathyroid hormone related protein (PTH-rp) since it has a striking structural homology with PTH in the first 13 amino acids of the N-terminus. Interestingly, after this portion of the molecule, the two protein sequences diverge completely. The PTH-rp protein structure is rich in sequences that might lead[e post-translational processing with multiple secreted forms.

The gene for PTH-rp resides on human chromosome 12. PTH-rp expression has been demonstrated in a variety of malignant tissues and their cells. Importantly, PTH-rp expression has been seen in normal tissue as well, including fetal parathyroid gland, keratinecytes, placenta, brain, lactating breast tissue, fetal liver, gravid uterus, and bone cells. The non-malignant expression of the PTH-rp gene may therefore be involved in normal regulatory processes in humans and in nonmalignant states, and serves as the basis of this presentation. Such states include keratinocyte differentiation and proliferation, mineral transport by the placenta, and perhaps regulation of intestinal vascular smooth muscle tone. Pathophysiologic, non-malignant states include idiopathic infantile hypercalcemia (IIH).

The normal physiology of PTH-rp will be emphasized by review of experiments that focus on the role of PTH-rp in ~r~t~nncyte different~tion~ their ~Vole in placental transport of minerals and in placental regulation of vitamin D metabolism, and their role in normal bone cell metabolism in children.

The abnormal, non-malignant pathophysiology of PTH-rp will be discussed by evidence supporting a role for this peptide hormone in the pathophysiology of IIH.

As is commonly seen in malignant disorders which express a novel protein with unexpected biologic effects, such proteins are commonly part of heretofore unexplained but normal physiologic processes. This is certainly true for PTH-rp. 1,25(OH)2D3 exerts its biological actions via activation of a nuclear receptor and is a major regulator of the calcium (Ca) metabolism at classical target organs as intestine, kidney and bone. 1,25(OH)2D3 also modulates the synthesis and secretion of PTH. Some rapid effects of 1,2S(OH)2D3 are independent of the genomic pathways and may require activation of a second messenger system. Recently 1,2S(OH)2D3 was shown to play an important role in the regulation of cell proliferation and differentiation in human and animal hematopoietic, cancer and epidermal derived cell lines. This large spectrum of activities led to the development and clinical application of vitamin D analogues with unique cell or organ specific actions.

24,25(OH)2D3 is a naturally occurring metabolite with a special role in bone metabolism. 24,2S(OH)2D 3 was shown to prevent the hypercalcemic effect of vitamin D derivatives in patients with renal insufficiency and in rats with reduced renal mass. In rats with intact kidney function and after 5/6 nephrectomy 24,25(OH)2D S was shown to suppress the levels of pre-pro-PTHmRNA, but this effect is far smaller when compared with that of 1,25(OH)2D3. In short and long term studies performed in rats with reduced renal mass, 24,2S(OH)2D3 in combination with 1,25(OH)2D3 suppressed the osteoclastic bone resorption associated with secondary hyperparathyroidism, but independent on the degree of suppression of PTH. The long term study in the above model showed that the combined therapy also significantly promoted bone formation.

A controlled multicenter study conducted by Popovtzer et al evaluated the effect of 24,25(OH)2D3 combined with I~OH)D3 as compared with 1 ~OH)D3 alone in hemodialysis patients. Analysis of transiliac bone biopsies following 13 months of treatment revealed that combined therapy markedly decreased the bone turnover and resorption, and suppressed the osteoclastic parameters. In contrast, treatment with 1 ~OH)D3 alone resulted in an increase in the bone volume without changes in the bone resorptive parameters. The results of this study suggest a therapeutic role for 24,25(OH)2D 3 with 1 ~OH)2D3 in uremic osteodystrophy.

1,2S(OH)222oxaD 3 (22 oxacalcitriol, OCT) was shown to be more effective than 1,25(OH)2D 3 in suppressing cell growth and differentiation in leukemia cell lines, in contrast, this derivative was found to bind less avidly to the chicken intestinal receptor. A low calcemic activity of OCT related to less effective stimulation of the intestinal Ca absorption and bone Ca mobilization as compared to 1,25(OH)2D 3 was confirmed in mice and rats. Studies by Brown have demonstrated that exposure of parathyroid cells to a single dose of OCT results in 60-80% suPPression of pre-pro-PTHmRNA. Thus OCT can provide an important tool in suppressing secondary hyperparathyroidism without the limitation of the hypercalcemic action of I~2S(OH) 2D3. 1,25(OH)222ene24homoD 3 (calcipotriol MC903), a recently developed analogue with a low calcemic activity but with a potency similar to that of I~25(OH)2D3 on the modulation of cell proliferation and differentiation, was shown to be effective in psoriasis, a hyperproliferative state with disturbed maturation of the epidermal cells. The analogue 1,2S (OH)216ene23yneD3 was found to be 7-fold more potent than 1,25(OH)2D3 with respect to inhibition of cell proliferation and differentiation of HL60 promyelocytes. In contrast it has only 2% of the intestinal Ca stimulatory activity and 3% of bone Ca mobilization potential of 1,2S(OH)2D S. These selective properties may enable 1,2S(OH)216ene23yneD 3 to become a therapeutic alternative in leukemia.

The factors affecting the biological activity and the selectivity of nonhypercalcemic vitamin D 3 analogues include: i) their affinity for the vitamin D receptor; 2) their affinity for serum vitamin D binding protein; 3) their biochemical structure. Thus analogues with strong binding to the nuclear receptor are very potent inhibitors of cell differentiation and proliferation. These analogues, however, have a low affinity for the vitamin D binding protein and their effect in vivo activity on Ca absorption and bone homeostasis will be almost negligible.

Conclusion: Expansion of clinical and experimental knowledge on 24,25(OH)2D 3 and the rapid development of other metabolites provide novel therapeutic options. 24,2S(OH)2D 3 in combination with IGhydroxylated metabolites is a potent suppressor of osteoclastic bone resorption in secondary hyperparathyroidism. OCT suppresses PTH synthesis and secretion like 1,2S (OH)2D3, but without its calcemic effect. MC903 and 1,25(0H)2 16ene23ypeD 3 selectively affect cell growth and therefore may be effective on conditions such as leukemia and psoriasis. It is known that urinary tract infection (UTI) may cause renal scarring; for this to occur, it has been thought that vesicoureteric reflux (VUR) must be present and therefore, the scarring has been referred to as reflux nephropat.hy (RN). The present symposium deals with the pathogenetic mechanisms concerning adhesion of bacteria, their capacity to elicit an inflammatory response, the reliability of diagnosing VUR by voiding cystourethrography (VCU), and the functional and morphological consequences of recurrent symtomatic U;I'I, i.e. pyelonephritis (PN). The adhesion of pathogenic bacteria to urinary tract epithelium is mediated by a specific interaction between adhesins on the bacterial surface and receptors on the epithelial cell surface. E. coli strains which cause symptomatic infection are characterised by their capacity to adhere to mucosal surfaces in this way. Competitive blocking of bacterial adhesion by receptor analogues has proved successful in an experimental model and it is possible that certain foodstuffs may contain naturally occurring inhibitors of bacterial adhesion. Further, information is now available regarding the mechanisms by which attaching bacteria elicit a mucosal inflammatory response. Bacteria stimulate epithelial cells to secrete various cytokines (eg. IL-6 and IL-8). 1L-6 activates hepatic production of C-reactive protein and acts as a pyrogen, thereby contributing to the systemic response in acute PN, while IL-8 recruits neutrophils to the urinary tract. In adults with RN, proteinuria associated with segmental glomerular sclerosis (SGS) is known to have a poor prognosis.

Proteinuria and SGS was found in approximately one third of a group of children with RN. Other histological features were increased glomerular size and parahilar and subendothelial hyaline deposits. These changes correlated inversely with renal size and glomerular filtration rate (GFR). Renal functional damage may occur at the time of the initial episode of acute PN, particularly in young children. Decreased GFR was found mainly in children with small or scarred kidneys and was not related to the presence or degree of VUR. Similarly, progressive deterioration of renal function occurred mainly in children with small kidneys and, again, was not related to VUR. The lack of correlation between VUR and renal functional damage might be explained, at least partially, by the unreliability of VCU in the diagnosis of VUR, particularly in children under 2 years of age. Approximately 30% of such children not showing VUR at first VCU were shown to have VUR at repeat investigation 6 months later.

In summary, this symposium clarifies some of the mechanisms (in particular bacterial adherence and mucosal cytokine production) by which UTI leads to renal scarring. Techniques for blocking adhesion hold out the hope of successful prevention and therapy in the future. While it seems likely that UTI can cause renal functional damage in the absence of VUR, it is clear that VCU underestimates the prevalence of VUR, particularly in young children. Children with scarred or small kidneys should have regular measurement of GFR. Finally, microproteinuria, in children as in adults, is associated with the development of SGS and its presence indicates a poor prognosis. Adhesion of pathogenic bacteria to mucosal surfaces is essential for the survival of the organisms because it confers on the pathogen the ability to withstand cleansing mechanisms and to overcome nutrient deprivation, resulting in growth advantages and enhanced toxicity. It is mediated by a specific intern&ion between (macro) molecules, termed adhesins, on the bacterial surfaces, that combine with complementary structures, termed receptors, on the animal cell surfaces. Three types of adhesin-receptor interactions have been described. One type involves protein (or lectin)carbohydrate interactions whereby bacterial lectins, expressed in fimbrial or nonfimbrial forms, bind the organisms to corresponding carbohydrates presented on the animal cell surfaces as glycoproteins and glycolipids. The other type includes protein-protein interactions mediated by specific regions of bacterial surface proteins that bind the bacteria to components of the extracellular matrix (e.g. fibronectin) or to the superfamily integrins on animal cell surfaces. The third type involves hydrophobic interactions in which a hydrophobin consisting of proteins or glycolipids (e.g. lipotheicoic acid) binds Lhe bacteria to hydrophobic regions of animal cell surface constituents. The knowledge gained from the molecular mechanisms of bacterial adhesion have served to design antiadhesive therapy as a new approach for the prevention of bacterial infections at the earliest step of the infectious process. One approach deals with the application of soluble inhibitors resembling the adhesion site of the receptor molecule in an attempt to block competitively the attachment of the bacteria to the mucosal surfaces. This so called "receptor therapy" by receptor analogues was documented in experimental infections using Escherichia coli that express either mannose or di-galactose specific fimbrial adhesins. It has been demonstrated that urinary tract infections caused by these organisms can be prevented by challenging the animals with bacteria suspended in solutions supplemented with the sugars specific for the bacterial adhesins. Another approach is based on the observations showing that sublethal concentrations of antibiotics suppress the expression of bacterial adhesins. It is an attractive approach because sublethal concentrations of antibiotics may reach mucosal surfaces intermittently during a typical course of therapy and interfere with the ability of the bacteria to colonize these surfaces. Last but not least, is the idea that inhibitors of bacterial adhesion may be found in certain diets. Especially are the recent findings showing that cranberry juice, a widely recommended juice for the treatment of (or prevention of recurrent) urinary tract infections, contains inhibitors of adhesins expressed by E. coli, ;':c most c,mmo, bactmia causing t~rinary tract infecnons. Uropathogenic E.coli adheres to mucosal surfaces via two fimbrial adhesins (designated MS and MR) protruding from the bacterial surface. Cranberry and blueberry juices from vaccinium berries contain two compounds that inhibit the E.coli adhesins. One is fructose, a constituent of all juices; it inhibits the MS fimbrial adhesin. The other inhibitor is a high molecular weight polymeric compound of unknown nature, found only in cranberry and blueberry juices and inhibits the MR adhesins of E.coli. This material was a more potent inhibitor of the activity of MR adhesins produced by urinary isolates including pyelonephritogenic isolates of E.coli than of those expressed by fecal isolates including diarrheal isolates. It is possible that the claimed beneficiary effect of cranberry juice is due to its antiadhesive agents which act in the gut (the source of uropathogens), in the bladder, or both by preventing colonization of these sites. In summary, a single clone of bacterial pathogen contains genetic information coding for multiple type of adhesins each of which exhibits distinct receptor specificity. The organisms also contain genetic information that enable them to switch on and off the expression of each type of adhesin at relatively high frequency so that one at a time one single adhesin is expressed. It appears now that in order to effectively prevent infection, the antiadhesion therapy should include agents which inhibit all the types of adhesins expressed by the bacterial pathogen. Infections of the urinary tract give rise to an inflammatory response. Granulocytes are recruited to the site of infection and are detected as pyuria. Localized inflammation of the bladder gives rise to dysuria and frequency. Systemic involvement can be detected as fever, elevated acute" phase reactants and elevated blood leukocyte counts. Indeed, the site and severity of the host infiammatory response is a major determinant of the symptoms of acute urinary tract infection. Pye!onephritis is commonly diagnosed as bacteriuria, fever, elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in combination with signs of renal involvement such as reduced renal concentrating capacity. Bacteria differ in the capacity to elicit the host response. This has been most extensively analyzed for Escherichia coli, which give rise to the majority of febrile infections in childhood. Febrile infections are caused by a subset of E.coli strains, which attach to the urinary tract mucosa, contain certain types of lipopolysaccharides and capsular polysaccharides, make iron binding proteins and are resistant to the bactericidal effect of serum. This association between certain bacteria and severe infections suggested that the virulent E.coli strains are more inflammatogenic than other bacteria. We have recently analyzed the mechanisms whereby attaching E.coli may induce a mucosal and systemic inflammatory response in the host.

Adherence was initially thought to be a colonization factor for the urinary tract. By attaching bacteria would resist elimination with the urine flow, and establish persisting bacteriuria. If so, a higher adhesive capacity would be expected to be found among strains causing asymptomatic bacteriuria which are carried by the individual host for extended periods of time. In contrast, adhesive capacity characterizes strains which cause symptomatic infections; especially acute pyelonephritis.

The systemic response during acute pyelonephritis resembles the spectrum of activities of cytokines such as Interieukin-6 (IL-6) and . We have demonstrated that these cytokines are synthesized in the urinary tract in response to E.coli infection. IL-6 is secreted into the urine within minutes to hours of colonization of the human urinary tract, and continues to be produced for as long as bacteriuria persists. Elevated serum IL-6 levels are mainly found in patients with acute pyelonepbritis. We therefore propose that IL-6 acts as a mediator from the local site of infection to systemic sites, and that spread of IL-6 from the urinary tract mucosa to the blood stream contributes to the induction of fever, CRP and ESR in acute pyelonephritis. IL-6 is, however, not known to be involved in granulocyte recruitment. On the contrary, experimental evidence has suggested that the IL-6 activation is independent of the neutrophil response. IL-8 is a wellknown chemoattractant for neutrophils. We recently demonstrated that IL-8 is secreted into the urine in response to E.coli infection. In animals, the neutrophil response coincided with the clearance of infection. It remains to be shown whether the individuals with potent IL-8 and neutrophil responses clear infection better than others.

In summary attaching E.coli bacteria elicit a mucosal cytokine response which consists among other of IL-6 and IL-8. IL-6 may contribute to the induction of symptoms such as fever, and to the acute phase response connected with acute pyelonephritis. IL-8 may on the other hand recruit granulocytes to the site of infection, and contribute to the eventual clearance of bacteria from the local site. Voiding cystourethrography (VCU) is regarded as the "gold standard" for the detection of vesicoureteric reflux (VUR) in infants and children. However, the reliability and reproducibility of VCUs have not previously been sufficiently evaluated.

We undertook a retrospective study of 92 children (185 ureters) in whom the VCU was repeated within a 6 month period; the group comprised 56. girls and 36 boys; 57 children were less than 2 years of age and 35 children 2 years and over. Children with neurogenic bladder or obstructive uropathy were excluded. Major indications for repeat investigation were VUR on initial study in 57, upper tract abnormality (by ultrasound, DMSA scan or intravenous urography) in 16, recurrent urinary tract infection (UTI) in 2, miscellaneous in 17. 42/92 children had identical findings or1 repeat VCU ( concordance rate 46%); in 136/185 ureters (i.e. 74%) identical or near-identical (i.e. +/-1 grade) degrees of VUR were found. In cases where the two VCUs gave different results, the discrepancies were due to the demonstration of both higher and lower grades of VUR on the second examination. 23 children with no VUR at initial VCU had repeat investigation; major indications for repeat VCU were upper tract abnormalities in 13, recurrent UTI in 5, miscellaneous in 5. 9 (i.e. 35%; [10% of the total group]) were shown to have VUR on the second examination. It is noteworthy that 8 of these 9 children were less than 2 years old at the time of the second study and that 3 of them have been subsequently shown to have persistently abnormal DMSA scans.

These data demonstrate the unreliability of VCUs, particularly in children under the age of two years, Reflex high-pressure voiding in response to rapid filling is common in the infant bladder; the resultant failure of adequate bladder filling may explain the high incidence of false-neqative VCUs in the under 2 year age group.

It may be prudent, in the management of infants with either UTI or upper tract abnormality with no demonstrable VUR, to consider repeating the VCU and certainly to give antibiotic prophylaxis. C 58 8-10.4 In previous studies on renal function in children with recurrent pyelonephritis (PN) we have shown that children with early onset PN (<3 years of age) are those who have a reduced GFR and that GFR is reduced irrespective of the presence or degree of vesicoureteric reflux (VUR). Furthermore we have shown that the number of PN episodes is of importance for the reduction in GFR but not the number of urinary tract infections.

In the present study renal function and radiology was followed up in 161 children with recurrent PN, with or without VUR and with or without scarred or small kidneys. The patients were followed for 1-21 years. Renal function was evaluated as the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), determined by clearances of inulin and PAH. 37 of 105 children, with originally normal kidneys, developed small or scarred kidneys and 22 of these 37 children had grade >3 VUR and 13 of 29 children with originally scarred kidneys developed small kidneys. 14 of the 37 children developed renal parenchymal damage after the age of 4-5 years. GFR was already <-2 SD of that of controls in 51% of the patients at the first renal function test and in 53% at the latest investigation. 69% of these patients with a GFR <-2 SD had small or parenchymally reduced kidneys and most of them were patients having their first PN before the age of 3 years. Patients with small kidneys had a lower GFR than those with normal-sized kidneys, whether scarred or not. The low GFR and the further reduction was related to kidney size and not to the presence or degree of VUR. In individual patients, however, the rate of progression could not be predicted from the radiological findings.

Patients with bilateral small kidneys seemed, however, to show the greatest drop in GFR during follow-up. A significant drop in GFR was also seen in patients with grade >3 refluxes operated on bilaterally and these patients also had a lower GFR at last investigation compared to those patients not operated on.

In conclusion the renal functional damage seems to occur early on during the disease and seems to be related to kidney size, and a further slow progression with reduction in renal function occurs but seems to be difficult to predict from the radiological changes in individual patients. Therefore, patients with recurrent PN should be followed regularly by GFR determined by an accurate method. Little is known about the early development of proteinuria and the glomerular changes in childhood, and to elucidate this renal biopsies were obtained from 24 patients with RN aged 5.2-18.8 years.

Urinary total protein was measured by Coomassie blue dye binding and expressed as protein (mg)/creatinine (bmol) ratios (Up/Uc) in early morning urine.

SGS was observed in 8 biopsies and traced through serial sections to a hilar origin in every case [I] . Up/Uc was elevated in 9 patients, and correlated strongly with the % glomeruli affected by SGS (p<0.0001).

We also observed parahilar hyaline deposits in 17 biopsies, and subendothelial hyaline deposits in the hilar arterioles in all cases [I] . These vascular changes, which had not previously been reported in humans with RN, may be analogous to those reported experimentally in rats following subtotal nephrectemy.

We subsequently quantified the glomerular and vascular alterations morphometrically by computerized digitometry [2] .

Similar measurements were made in biopsies from 19 controls comprising recurrent haematuria (13) and nephrotic syndrome (6) without significant structural abnormalities.

In RN patients renal parenchymal surface area was measured from IVU tracings, and total and split renal function was determined by 99mTc-DTPA slope clearance and renography.

The mean cross-sectional area of patients'

glomeruli was double that of controls. Glomerular size correlated with the amount of proteinuria and inversely with both renal size and GFR. Compared with controls, the hilar arterioles in RN were thicker, had more intramural hyaline deposits and lumens which, while actually increased in calibre, were narrower when related to glomerular size.

The increased glomerular size and proteinuria are consistent with hyperfiltration.

We have previously demonstrated a close association between parahilar hyaline deposits and hilar SGS in the nephrotic syndrome [3] .

The comparative incidence of these lesions and of the insudative hilar vascular deposits suggests a sequence beginning with subendothelial injury and culminating in SGS.

Microproteinuria is a useful marker for the development of SGS and should be monitored regularly in all patients with RN. Few, if any, question today the existence of a nephropathy associated with the Human Immunodeficiency Virus (HIV) infection, and referred to as HIVN or HIVAN. This nephropathy may develop at any stage of the infection, prior to or following the appearance of the full Syndrome of Acquired Immunodeficiency (AIDS). HIVN is consistently identified by excessive proteinuria or albuminuria (Albustix ~i+, total protein/excretion ~100mg/mZ/day or protein:creatinine ratio > 0.13) identified on repeat occasions at least two weeks apart in the absence of fever.

Other findings associated may include a Nephrotic Syndrome, normal blood pressure, enlarged and hyperechoic kidneys, rapid progression to End Stage Renal Disease, and no response to conventional treatment. In HIV+ patients with abnormal protein excretion, urinary tract infection, GU anomalies, and non-HIVN renal disorders need to be searched for.

Ideally, patients presenting with renal disease and who live in an area endemic for HIV infection, should be suspected of having HIVN and studied accordingly.

The A renal biopsy is recommended when HIVN is diagnosed clinically in order to further define the diagnosis, prognosis, and for potential therapeutic decisions. Currently we are studying the natural history, clinical presentation and outcome of HIVN in children. When only those infants and children identified through their HIV+ mothers were included, we followed prospectively 149 patients between January 1981 and De~,T~e~ 1990.

Of those, 28 (18.8%) developed HIVN.

When all HIV+/AIDS children seen during the same perio4 d~ time were included, of a total of 398 patients, 55 (14%) developed HIVN.

Diagnosis of AIDS was made in 42 cases.

Mode of transmission of HIV was perinatal in 96% of the patients. Mean age at onset of nephropathy was 30 months (range 0.03-179). Proteinuria was intermittent in 23 patients (42%) and persistent in 32 (58%). Edema and/or hypealbuminemia was present in 34 (62%). 13 (24%) developed renal insufficiency and three underwent dialysis.

Time from onset of HIVN to chronic renal failure was 9 ~ 6 months (range !-22%. 27 patients {d9%) z::; ~-~ fre~ nen-rgn~l ca-se9. Prognosis of HIVN depends on histologic changes.

In general, Black North American and Haitian adults and children evidence a worse course in their renal disease than their Caucasian counterparts.

Adults who develop HIVN follow a rapid downhill course and die sooner than those without renal involvement. Anti-retroviral treatment hopefully will slow down the progress of the nephropathy and the irreversible course toward death;

such anecdotal and brief observations have been reported but well designed studies are needed to further define and maybe confirm these observations. Doses of all drugs should be modified in accordance with manufacturer's recommendations. This is particularly true and difficult for anti-retroviral medications due to the paucity of information on their pharmacokinetics in Chronic Renal Failure and End Stage Renal Disease. Hemodialysis has yielded relatively poor results among adults with HIVN.

Peritoneal dialysis has been well tolerated by children and adults.

Renal transplantation has been used with great caution and mixed results.

Further studies should be undertaken in order to identify the various processes specifically leading to HIVN in children, and the best potential measures for its prevention or treatment.

S-t1.3

According to the last report of the European Center for Epidernilogical Monitoring of AIDS (1), Spain is the country having the highest incidence of cases. Analysis of pediatric AIDS surveillance revealed that 395 cases of pediatrics AiDS have been registered in Spain until the end of 1992. This accounts for about 3% of all cases of AIDS, a percentage higher than the cumulative pediatric percentage of 2% observed in USA and the rest of Europe. The continous increase in the relative percentage of these cases in Spain indicates rapid spread of the disease in this group. All cases of pediatric AIDS in Spain are whites.

Although renal disease is not considered a common clinical manifestation of AIDS, aproximately 10% of the adults and 7% of pediatric AIDS patients are affected, To assess the situation of childhood HIV-associated nephropathy (HIVAN) in Spain, a survey of Spanish divisions of Pediatric Nephrology was undertaken in 1990 (2) . Three children with renal disease were identified. Clinically all three had proteinuria, two hematuria and none renal failure, One was found to have focal and segmental glomeruloesclerosis. Only one was alive and free of proteinuria after treatment with prednisone.

To know the actual prevalence of renal disease in HIV-infected children two years later, we performed a new survey to 15 Spanish hospitals with divisions in Pediatric Nephrology, The questionaire included a retrospective analysis of their experience with HIV infected children and renal manifestations, Several aspects of clinical presentations were assessed. Clinical renal disease was considered when one o more of the following manifestations were present: -persistent urinary excretion (found on more than two occasions during a period of at least four weeks) of more than 0.1 g of protein per square meter of body surface area per day, an AIbustix reading above 1+, or a urinary protein/creatinine ratio greater than 0,1 -heavy proteinuria was diagnosed when there was persistent excretion of more than 1 g, of protein/m2/24 h, an Albustix reading above 2+, or a urinary protein/creatinine ratio greater than 1,5,

The thirteen centers (80%) that responded to the questionaire controlled 694 HIV-infected children (Class P-0: 454, Class P-l: 98, Class P-2: 142), Ten of them had screening program to detect renal disease in HIV infected children since 1989. Of the resDonders 11 had diagnosed no new patient with HIVAN or HIV infected patients with clinical renal disease in the last two years, since the first survey, Only two centers, from Madrid and Asturias respectively reported two new cases, one each, with clinical manifestations of HIV infection and renal disease, but without histologic confirmation the first one. They were two white girls, 24 and 2 months old respectively with proteinuria but without hematuria, chronic renal failure neither hypertension. The patient from Madrid died from infectious cause eleven months after diagnosis. The infant from Asturias, who decesed as a result of pneumocystic pneumonia at the time of diagnosis, showed in the necropsia focal and segmental glomeruloescterosis as typical changes of HIVAN Inmunofluorescence and ultraestructural studies were not performed, Our present report draws attention to the fact that the occurrence of HIVAN in the pediatric population in Spain is rare, This low incidence suggests that unrecognized factors, such as race, may be important in the development of renal disease. HIV associated nephropathy, clinically manifested as heavy proteinuria and progressive renal insufficiency, pathologically is characterized by regularly occurring glomerular and tubular abnormalities.

The glomeruli are enlarged, and a variable number are affected with segmental sclerosis most commonly in early stages of evolution; extensive or localized capillary wall collapse may be associated.

There is both hypertrophy and hyperplasia of visceral epithelial cells which are coarsely vacuolated and contain protein reabsorption droplets.

Tubules are microcystically dilated, filled with precipitates of filtered plasma proteins which are in continuity with similar precipitates in Bowman's space of the same nephron.

Tubular cell necrosis is regularly foun~, even in the absence of nephrotoxin exposure or clinically evident renal hypoperfusion.

There are numerous ultrastructural cellular abnormalities, most commonly widespread tubulo-reticular structures.

This unique combination of structural alterations occurs regardless of the clinical manifestations of HIV infection and is not infrequently the initial indication of this viral disorder.

Unlike other forms of renal disease in HIV infection, HIV associated nephropathy is almost exclusively limited to blacks.

Affected patients had acquired HIV-infection by all manners of transmission.

The reason(s) for this racial predilection are unknown, although it explains the seemingly contradictory reports of its absence in certain geographic areas.

The pathogenesis of this nephropathy is currently under investigation, both in humans and in some experimental models.

Few rhesus monkeys with simian immunodeficiency viral infection have developed segmental glomerulosclerosis.

The full combined lesion has been produced in mice transgenio for HIV genes; viral protein was identified in sclerotic qlomeruli in these animals, suggesting a role for viral genome in the genesis of this disorder.

In humans, there is conflicting evidence on the role of direct viral infection of renal cells in pathogenesis.

In some studies, HIV genome has been documented in glomerular and tubular epithelium by tissue in situ hybridization, whereas in others it has not. Additional suggested mechanisms of renal injury include infection with Mycoplasma fermentans and alterations in renal hemodynamics.

Finally, glomerular enlargement, a feature common in AIDS patients is suggested to be predecessor of focal segmental glomerulosclerosis. Normal acidification comprizes the almost complete reclamation of filtered HCO3-, the titration of buffers such as HPO42and the excretion of NH 4 +. The first process amounts to some 4.5 mol/day, the second to 20-30 mmol/day, and the NH4+ excretion is variable depending largely on the acid base status (20-500 mmol/day). Since the early work of Pitts and Alexander [1] it has been clear that the task of renal tubular acidification is accomplished by Na+-dependent H+-secretion. It took 31 more years untiLMurer et al. [2] eventually proved this concept by demonstrating Na+/H+ exchange. This exchanger is responsible for more than 90% of the tubular reabsorption of HCO3-. It is present in the luminal membrane proximal tubule (PT), mostly in the Sl-segment, and in the thick ascending limb of the loop of Henle (TAL). Many of the regulatory properties of this exchanger have been unravelled [3] . It is upregulated by a fall in cytoso{ic pH, by hormones such as PTH and ang}otensin {{, and it is inhibited by amiloride-like compounds such as EIPA. This exchanger seems to occur in several forms. One present in fibroblasts has recently been cloned [4] , and it appears likely that this "housekeeping", i.e. pH-regulatory system, is present in many if not every cell. The luminal membrane Na +/H+-exchanger is a close relative and is currently cloned by Pouyssegur and collaborators. In essence proximal tubule acidification can be described as the secondary active reabsorption of NaHCO 3. For this to occur, a HCO3--export system in the basolateral membrane must also be present. This seems to be a Na +(HCO3-) 3 carrier [5] . This transporter is inhibited by stilbenes, which are known to interact with the band 3 protein (HCO3"/CI--exchange) of red blood cells. Due to its 2 extra negative charges this system is vcltage depgndent. This explains why high plasma K + concentration impedes HCO 3-reabsorption and hence causes systemic acidosis. Apart from its predominant role in HCO3"-reabsorption the PT is also the main site of NH4+ production. This process becomes highly relevant in chronic metabolic acidosis, inasmuch as an increased delivery of glutamine is metabolized essentially to NH 4+, CO 2 and H20. Glutamine is delivered from the liver for the sake of a reduced urea production. This saves HCO 3" in the liver and hence corrects metabolic acidosis, but shifts the burden of N-metabolism and excretion from the liver to the kidney. NH 4 + produced by the PT is secreted in the collecting tubule (CD).

The main task of the TAL in renal tubule acid excretion is the continuation of HCO 3-reabsorption. This occurs via Na+/H + exchange in the luminal membrane and basolateral exit of HCO 3" probably via basola-~ra; ;;~+(HCO3-) 3 exchange [6] . i[ should be clear tnat the rate ot HCO 3" reabsorption in this nephron segment amounts to only 10% of the filtered load. The TAL segment is also relevant inasmuch as it is the main site for accumulation of NH 4 + in the interstitium of kidney me-du{{a. This occurs via NH4+ reabsorption through the furosemide-sensitire Na + 2CI-K +-carrier [7] .

In the CD four processes are of relevance for the issue of acid base balance: H+-secretion by (i.) a vacuolar type of H +-ATPase, located in the luminal membrane of A-cells [8] ; (ii.) H+-secretion by a omeprazol sensitive H+/K+-ATPase [9] ; (iii.) HCO3--secretion by B-cells in states of metabolic alkalosis; and (iv.) NH4+-secretion in states of metabolic acidosis. The mutual relevance of the first two processes are under investigation. Abundant data favors the existence of the vacuolar type proton pump in the luminal membrane of A-type cells, but more recent data also shows compelling evidence for a H+/K+-pump as it is present in the oxyntic cells of stomach. Both pumps can reduce tubule lumen pH to well below 4.5. HCO3--secretion, in the state of metabolic alkalosis, has been looked at as a mirror-type remodelling of the A-cell. This view probably will not hold inasmuch as the luminal HCO3--exporter is immunologically not identical to the basoiateral band-3-type exchanger present in the A-cell. Also the H +-pump, claimed to be present in B-type cells is as yet poorly characterized. The fourth task is the shortcircuiting of NH4 + in the kidney medulla. This secretory process is poorly understood at present. It is likely that NH4+ is taken up via basolateral K + channels.

Recent data have also cast some light on the interplay of K + and H + homeostasis in the kidney: (i,) The Na+(HCO3")3 exchanger in the proximal tubule helps to explain the K + induced changes in acid base balance (c.f. above). (ii.) The existence of a distal tubule H+/K+-AT-Pase might explain the hypokalemia of distal tubule renal acidosis. (iii.) The pH-sensitivity of distal tubule K+-channels in the luminal membrane explain the increased urinary K + losses in alkalos}s [ However, the increase in HC03 reabsorption was less in the newborn than in the adult.

Proximal fractional reabsorption of HCO3 was suppressed in both age groups but more so in the newborn.

With volume expansion there was further decrement in proximal fractional HCO3 reabsorption with increasing HCO3 loads, but this decrement with yolume expansion was less in the newborn than in the adult.

Thus, increased back leak is not the major reason for the lower bicarbonate reabsorption with increasing HCO3 loads, since if it were, volume expansion should have produced a greater, not a lesser decrement in bicarbonate reabsorption in the newborn compared to the adult.

When carbonic anhydrase was inhibited with acetazolamide, differences between newborns and adults were diminished. Raising filtered HCO3 loads significantly suppressed proximal C1 reabsorption in both age groups but the sum of C1 + HC03 reabsorption did not change nor did Na reabsorption.

These results indicate that in both mature and immature nephrons the proximal tubule apical membrane proton pump and basolateral membrane CI/HCO3 exchanger account for the load dependency of proximal HCO3 reabsorption.

The proton pump responsible for the increments in bicarbonate reabsorption during HCO3 loading is most likely H+,ATPase rather than the Na+/H+ antiporter since in the latter case parallel changes in sodium and bicarbonate reabserption would be expected to occur.

In addition, renal carbonic anhydrase activity in the immature proximal tube is sufficient to permit maximal HC03 reabsorption at physiologic filtered HCO3 loads; however at high HC03 loads the activity of the enzyme in the immature nephron is not sufficient to allow as much HC03 reabsorption as it does in the mature nephron. The distal renal tubular acidosis (RTA) syndromes are usually characterized by the presence of a hyperchloremic type of metabolic acidosis often associated to either hypokalemia (classic RTA) or hyperkalemia (hyperkalemic types of RTA). Some patients, however, have subtle defects in urinary acidification not manifested by hyperchloremic metabolic acidosis. The identification and classification of the various types of RTA is best approached from a mechanistic point of view and should take into consideration the site of the nephron responsible for the defect in acidification.

In considering the pathophysiological basis of distal RTA, it is best to view this in the context of normal mechanisms of H+ secretion in the collecting duct which .is largely mediated by an apical membrane H+ ATPase. Also of relevance to the understanding of distal RTA is an understanding of axial heterogeneity in the distal nephron.

The cortical collecting tubule possesses three cell types: a principal cell which absorbs Na+ and secretes K+, a type A intercalated cell which secretes H+, and a type B intercalated cell which secretes HCO3-. This allows the cortical collecting tubule to secrete either acid or base, in response to changes in dietary acid. In addition, this allows H+ secretion from the cortical collecting tubule to be regulated by changes in transepithelial voltage secondary to changes in Na+ transport. The medullary collecting tubule, on the other hand, appears to secrete only H+ ions and there is no net Na+ transport or K+ secretion. In states of chronic K+ deprivation, this ~gmen[ is c~pable u[ abso~biny K+, mull ~ikely us;rig the apical membrane H+/K+ ATPase. Whether a defect in this pump can explain the development of hypokalemic distal RTA will be considered.

A classification of distal RTA based on the deranged cellular mechanism of urinary acidification will be presented. Some of the proposed mechanisms are represented by relatively well defined clinical entities whereas others remain theoretical. P a t i e n t survival and graft survival after the 1st t r a n s p l a n t a t i o n were similar to p a t i e n t s w i t h o t h e r p r i m a r y renal diseases. c c e s s f u l p r e g n a n c y after start of RRT; almost all p r e g n a n c i e s occurred after t r a n s p l a n t a t i o n , The p e r c e n t a g e s of neonatal deaths and m a l f o r m a t i o n s w e r e not d i f f e r e n t from p r e g n a n c i e s of h e a l t h y mothers. M e a n g e s t a t i o n a l age and m e a n b i r t h w e i g h t w e r e reduced, however, Measurement of GFR is essential in the assessment of renal function and the progression of renal disease as well as in the evaluation of renal response to therapeutic maneuvers. "Ideal markers" for GFR should be completely filtered by the glomerulus without tubular secretion or reabsorption and should have no extrarenal metabolism. In addition they should be easily, accurately and inexpensively quantifiable in small amounts of blood and urine. No single marker fits all these criteria, and few meet enough criteria to be used for research studies, especially in clinical trials where multiple centers are participating. In pediatrics, an ideal GFR method should also preclude the need to collect urine, since accurate urine collection is technically difficult, especially in children who have bladder anomalies or who have undergone urinary diversion. The urinary clearance of exogenous inulin has been the "gold standard" for GFR in research studies. Inulin clearance by the infusate method without urine collection has been equally accurate and reliable in children, but inulin is not easy to prepare, its constant infusion is laborious, and from time to time it is difficult to obtain commercially in the USA. Other methods are desirable for multicenter studies. Neither timed urinary creatinine clearance (usually 24 hours) nor estimation of ereatinine clearance from serum creatinine and patient height or weight is accurate or reproducible enough to be an acceptable research alternative. Newer methodologies, such as the plasma and renal clearance of single injections of radionuclides (e.g. Tc~-DTPA and CrS*-EDTA) and the clearance of radiographic contrast agents, like iothalamate, have been used successfully as research tools, mostly in single center studies. In 1990, the SPNSG began a controlled multicenter trial of growth hormone therapy for children with chronic renal insufficiency (GFR 10-40 ml/min/1.73m2). This study required accurate assessment of GFR at 0, 3, 12 and 24 months of study in each patient at 20-25 different centers. The clearance of nonradioactive iothalamate by the infusate method (GFR,o) was chosen as the best available method. Conditions of the test were standardized to be performed the same way by a research nurse in each center. After a priming dose, iothalamate was infused continuously at a rate equal to the estimated urinary excretion rate to maintain a steady state serum concentration near 1 mg/dt. The infusion continued for 5 hours in all children except those < 3 y.o. with estimated GFR < 35 ml/min/1.73m 2, in whom the infusion was continued for 8-12 hours to be sure steady state was achieved. Hydration with non-sodium containing fluids delivered at 3-10 ml/kg/hr was maintained during the study. Serum samples were obtained hourly during the last 3 hours of study, when patients were expected to be at steady state. Samples of infusate and serum were mailed on dry ice to a central lab, where the concentration of iothalamate was measured by HPLC. Results were rejected if the 3 serum values did not reflect a steady state, the serum iothalamate concentration was > 1.5 mg/dl, or the infusate concentration was <70% of predicted value. During the last 2 years, 112 GFR,o studies have been performed in 57 children, ages 2-15 years (mean 6.5 years), at 21 centers. Absolute GFR~o ranged from 2.5-35 ml/min. 14 studies (13%) were rejected for technical reasons, usually because an error was made in calculating or measuring the iothalamate dose (7/14) or the wrong infusion rate (3/14) was used. Errors occurred at 11 different centers (52%), usually during the first few studies performed by that center. Only 2 patients (3%) required more than one repeat study to obtain a technically acceptable result. One family refused a repeat study, but continued with regularly scheduled studies. In general, these studies was acceptable to both nurses and patients, despite being labor intensive and invasive. The GFR~o is an accurate, reproducible method, even at the lower ranges of absolute GFR, and can be standardized for pediatric multicenter trials. Although the GFRIo is the current method of choice for studies of the SPNSG, a less expensive, noncontinuous infusion method is still desirable for future studies. 4) Heredo-familial diseases (73 cases (9.9%), mainly policystic kidney disease, nephronoptisis and Alport Syndrome. 5) Others: 56 (7.6%).

The incidence of CRF by reflux nephropaty and hemolytic uremic syndrome was higher in Argentine compared with the incidence in Colombia and Venezuela; while the incidence of focal and ~:~ glomerulo-sclerosis was higher in Venezuela.

patients (aprox. 13%) either died without rehabilitation or were lost of follow up. 242 patients (33) % went into end stage renal disease and were included in dialysis, either hemodialysis (HD) (144 cases-59.5%-) or continuos ambulatory peritoneal dialysis (CAPD) (96 cases -39.7%-). HD was de modality of dialysis more used in Argentina (85.4%) of the cases, while CAPD has been used in Venezuela and Colombia in about 90% of the patients. During the studied period iii children were transplanted. 64% from live donors and 38% received cadaveric kidneys.

This study is the first report on CRF in children in Latin American countries and shows results about incidence, etiology, etc. of chronic renal failure and rehabilitation aspects of ESRD in children in this geographical area of the world. S-13.5 Multicenter controlled trial in nephrotic Syndrome in Japanese children Hiroshi Ito*, Norishige Yoshikawa** * Dept. of Nephrology National Children's Hospital ** Dept. of Pediatrics, Kobe University

In order to prevent frequent relapse and serious side effects of steroid in nephrotic syndrome (NS), we conducted a prospective multicenter controlled trial in Japanese children with NS. I. Traditional Chinese Medicine (Sairei-to) study The study was designed to test whether Sairei-to (ST), in combination with prednisolone (PSL), prevent or lessen the frequency of relapses in children with steroid sensitive NS. One hundred and fifty-eight patients with a first attack of idiopathic NS entered the trial between January 1987 and December 1989.

They were randomized into control (A) (PSL only) or Sairei-to (B) (PSL + ST] groups.

The same PSL regimen was used for two groups at the first attack and subsequent relapse.

Patients with steroid resistant (20) and with drop-out (5) were taken out of the study.

One hundred and thirty-three patients with steroid sensitive NS (69 of group A, and 64 of group B) completed the 2 year study period.

Number of frequent relapser was 25 out of 69 (36%) in group A and 17 out of 64 (27%) in group B.

Number of relapses in the second year was 0.50 + 0.86 in group A and 0.25 + 0.51 in group B (P<0.~5).

Cumulative seroid -dosage at the second year was 92 + 171 mg/kg in group A, and 33 + 60 mg/kg in group B (P<0.05). No patients have any serious side-effects of ST. Above data suggests that ST reduces the incidence of frequent relapse with no side effects in children with steroid-sensitive NS, and its use results in lower steroid dosage in those patients. II. Long-term steroid trial

The study was designed to assess the preventive effect of initial long-term steroid therapy on subsequent relapse in children with id'iopathic NS.

They were randomized into control and trial groups.

In the control group (A), PSL was given with ISKDC regimen for 8 weeks.

In the trial group (B), PSL was given with the starting dose of 2 mg/kg/day for 4 weeks, followed by 2 mg/kg every other day for 8 weeks.

Then, PSL was tapered by 0.5 mg/k 9, every 2 weeks and was off after 6 weeks.

At the subsequent relapse, in both groups, PSL was given with the dose of 2 mg/kg/day until the urine was negative for 3 days, after which the same dosage was given every other day for 2 weeks.

Then it was tapered by 0.5 mg/kg every 2 weeks and was off after 6 weeks.

The patients received ST in the whole study.

One hundred and forty-four patients with a first attack of idiopathic NS entered the trial between January 1990 and November 1991.

Patients with steroid resistant (15), and with drop-out (ii) were taken out of the study.

One hundred and eighteen steroid sensitive patients (58 in group A, 60 in group B) were followed up for a mean of i0.0 + 6.0 months. The percentage of frequent relapsers was assessed in each group by life-table method.

During 12 months of follow-up, they were not statistically different between 2 groups.

Above preliminary data suggests that initial longer steroid therapy is not more effective than conventional steroid therapy to decrease the number of frequent relapsers. In a prospective therapeutic trial, renal growth and function, the incidence of new renal scars or other morphological change, and the incidence of urinary tract infections (UTI) have been evaluated for 5 years in children with dilating vesico-ureteric reflux (VUR) under medical and after surgical management. Based on patient characteristics at entry and events associated with an i, ncreased risk, we give recommendations for an individual patient handling.

PATIENTS AND METHODS: 321 children younger than l l years with primary VUR grades 111 or IV (international grading) into one or both ureters and with a history of UTI were randomized to medical and surgical management stratified for sex, age groups, VUR grade, presence of .'enal scan'ing, interval since last UTI, and treating centre. After randomization, 15 patients (3 med., 12 surg.) did not follow the allocated treatment. Thus, 306 patients (73 males, 233 females) were treated according to their randomization, 155 medically and 151 surgically.

Voiding cystourethrographies. The severity of VUR in x-rays was graded by a panel of three radiologists.

All children entered with intravenous urography (IVU), and follow-up IVUs were planned 6, 18 and 54 months after entry. All fihns were assessed by at least 3 observers. Renal length, parenchymal thickness at upper and lower poles and at lateral zones, and the size of projected renal area (PPA) of each kidney were measured acc. to Jorulf et al. (1978) and Claesson et al. (19g 1) . For renal scarring, Hodson's definition (1959) was used. Thinning of renal parenchyma was defined as redaction of parenchymal thickness by at least --2.5 SDS with normal underlying calyces.

After .9~-mTc-DMSA injection, the relative uptake percentage was measured for each kidney.

Medical management consisted of antibk)tic prophylaxis with attention to fluid intake, bowel function and regular complete micturition as long as the VUR persisted. In the surgicaI group, identical medical management was applied until 6 months after openuion.

To detect UTI during follow-up, urine culttu'es were performed regularly with dipslide. When such a culture indicated bacteriuria or when symptoms of UTI including unexplained fever occurred, the patient was reexamined. For a diagnosis of acute pyeloneph.'itis (PN), significant bacteriuria, lever of at least 38.5~ without evidence of another infectkms disease, or loin resp. back pain, or general fatigue was required. Additional determination of Creactive protein (cut off 30 rag/l) or sedimentation rate (cut off 25ram/h) was used to strenghten the diagnosis when possible.

1. Risk of new renal scars Without significant differences betweeu the treatment groups, the incidence of new scars within 5 years (39 children) was 22ck in the 97 children entering the study under the a~e of 2 years, compared with 7% of the 122 recruited between 2 and 5 years, and 10c/c thereafter 187 patients).

VUR was present in all the renal traits de,mloping new scars. From the 39 children with new scars+ 30 bekmged to the 175 with bilaterally dihtting VUR and 34 to the 195 with uui-or bilateral grade IV VUR at entry.

Among the renal charactcrislics at entry, parenchymal thinning ( 13 out of 52 children, compared with 26 out of 254) and relative DMSA uptake of less than 45% (24 out of 155 kidneys, c(nnparcd with 19 out of 445) were associated with an increased risk of new scars.

Half of the children with P_~N during follow-up developed new morphological changes. However, fl'om the 39 children with new scars. 23 had documented UTI between two weeks prior to entry and the end of the 5 year follow-up.

In the surgical group (237 operated ureters), postoperative obstruction was clearly ass(x:iated with renal scarring (6 out of 10 exposed kidneys vs. 15 out of 227 kidneys without surgical complicatkm).

While the incidence of all syml~tomatic recurrences was not different in the two treatment groups, the number of children with PN was significantly smaller after surgical (15 out of 151) than under medical management (33 out of 155"). The incidence of UTt was nmch higher in infants than in children older than 2 years, particularly in boys. The influence of surgery as isolated event can be doctmrented for -the time until 6 i:nonths after allocation, during which all the patients received the same medical management, including antibiotic prophylaxis. After surgery, recurrences of PN dropped from 0.014 per patient month to 0.003. In comparis(m, in the medical group the 0top of the UTI incidence was somewhat smaller (0.034 to 0.0t 1). From all 85 episodes of PN, only 14 occurred in children without VUR documented in the ne• voiding cystourography (66 with VUR, 5 with questionable result). Ob'dously the disappearance of VUR, regardless whether occurring spontaneously or after surgery, is protecting to a high degree against PN.

3. Risk of post-surgic:d obstruction 86 patients had bilateral and 65 unilateral surgery (total of 237 ureters). Ten ureters (in 10 patients) were postoperatively obstructed (6.6% of the patients, 4.2% of the ureters). 7 of these children needed re-operation, all on the left side and in young children (mean 2 years).

Our data lead to the following reconm~endations for the individual management of children with dilati.g primary VUR:

Surgery deserves preference in children with a history of recurrent acute PN in spite of adequate medical management including antibiotic prophylaxis, and in children with anticipated bad compliance.

In all other patients, mecial martagement is equivalent to surgical.

Particularly close observation regardless of medical or surgical management is necessary in children with bilaterally dilating VUR, with renal parenchymal thimfing, with tmilateraHy or bilaterally small kidneys and/or with a relative DMSA uptake of < 45%.

In case of surgical ulanagement particuhu" care during the operation is required on the left side and in children younger than 2 years.

Preferences of informed parents and children have to be observed in any child.

S-14.1 CONGENITAL NEPHROTIC SYNDROME O. Koskimies and C. Ho]mberg Children's Hospit~, U~versi~ of Helsinki, SF-00290, HelsinkJ Finland Nephrotic syndrome ( NS ) detected soon after birth can be acquired, idiopathic or part of another syndrome. The acquired forms are most often due to syphilis or intrauterine toxoplasmosis, rubella, or cytomegalovirus infection, or due to thrombotic complications. The idiopathic forms of NS,are the congenital nephrotic syndrome of the Finnish type ( CNF ) or diffuse mesangial sclerosis. In addition, congenital NS has been reported to occur associated with brain malformations, with gonadal dysgenesis ( Drash syndrome ) and with other rare syndromes; in addition some cases cannot yet be classified ( I ).

A total of 41 infants with congenital NS were diagnosed in Finland during the years 1985 -June 1995. Of them32 were considered to have typical CNF and the rest were classified as having "probable CNF" ( 2 ), or "syndromic forms of NS" ( 7 ) . Nine ( 22% ) patients have died, 5 already during early infancy with severe neurological and/or cardiac disease and the rest during dialysis,usually because of infection and cardiac failure.

A total of 24 patients with CNF and 2 with other congenital NS have undergone renal transplantation. Three patients developed post-transplantation NS and renal insufficiency, with eventual loss of graft -one of them has recieved new renal transplant. One child developed NS without signs of renal insufficiency and one patient has slowly deteriorating renal function without other symptoms. Thus problems were encountered in 5/26 ( 19% ) children, while the rest are symptomless, grow and lead normal life.

Familial cases are seen also in other types besides CNF suggesting recessive mode of inheritance ( I ). Some patients with severe multiorgan involvement seem to be incompatible with life, while most patients with CNF grow and develop normally after renal transplantation. Since the original studies of Risdon (1968) , Striker and Schainuck (1970) , it has been recognized that chronic TI disease is the best histological correlate of GFR and ultimate prognosis in patients with primary glomerular diseases. The basis of this relationship remains unclear although several possibilities have been proposed. This presentation will focus on one central hypothesis: (1) proteinuria per se initiates acute TI injury; (2) inflammatory monocytes/macrophages (Mo) actively participate in renal fibrogenesis; (3) progressive tubular atrophy and interstitial fibrosis causes a declining GFR.

In clinical studies, severe sustained non-selective proteinuria is a bad prognostic indicator. In experimental nephrotic syndrome induced by puromycin aminonucleoside (PAN) proteinuria was shown to correlate with TI inflammation dominated by M~. Reduction of proteinuria by dietary protein-restriction attenuated TI disease. This relationship was confirmed in rat models of overload-proteinuria. Tubular cell injury appears to be an early and important feature which may be induced by urinary proteins for a variety of reasons: (1) release of lysosomal enzymes; (2) complement-mediated; (3) release of reactive oxygen metabolites; (4) tubular obstruction; (5) direct tubular toxicity; (6) lipoprotein-mediated. Ischemia may amplify the damage. Not all urinary proteins are detrimental: albumin may not be harmful, accounting for the absence of TI disease in patients with minimal lesion nephrotic syndrome. Tubular injury may then trigger events leading directly to interstitial Mo recruitment and fibrosis while the tubule itself regenerates or atrophies.

Mo are an important subset of the interstitial inflammatory cells present in all human glomerular diseases and experimental models with non-selective proteinuria. Mo depletion can attenuate interstitial fibrosis suggesting that M~ play a key role in fibrogenesis. Occasionally, TBM antibodies or immune complexes ]nay iniLiate the Mo influx but in most situations humoral mechanisms are absent and the mechanisms of M~ recruitment are unclear. Proposed pathways include: (1) T-cell mediated. In this context the expression of MHC class II antigens, ICAM-1, and antigen presentation by proximal tubular cells may be important; (2) complement-dependent; (3) chemoattractantdependent.

In PAN and protein-overload models, T-cells and complement proteins are not required. Increased renal mRNA levels for monocyte chemoattractant protein (MCP-1) suggests that MCP-1 may play a role in PAN nephrosis. In overload-proteinuria a urinary neutral lipid with M~ chemoattractant properties has been identified. A cDNA for Rantes, another Mo cbemoattractant, has been isolated from murine tubular cells but its role is presently unknown.

It is likely that tubular cells and interstitial fibroblasts synthesize most of the matrix proteins which accumulate during progressive TI fibrosis while M~ play an important role as a source of fibrogenic cytokines, especially TGFt~I. In PAN nephrosis, increased renal mRNA levels for TGFgl coincide with increased mRNA levels for interstitial matrix proteins (procollagens I and III, fibronectin) and basement membrane proteins (procollagen IV, laminin). Persistent nephrotic syndrome induced by multiple injections of PAN sustains the increase in these mRNA levels and results in progressive TI matrix accumulation. Treatment of acute PAN rats with a low protein diet or lipid-lowering drugs normalizes TGFfll and matrix mRNA levels. In both the acute and chronic models, matrix degradation may also be decreased by the production of the tissue inhibitor of metalloproteinases (TIMP). Although additional studies are needed, correlation analysis suggests that Mo may be a source of TGFfll and TIMP.

Reduction of GFR by TI fibrosis may be due to (1) generation of atubular glomeruli; (2) obliteration of intertubular glomeruli; or (3) release of vasoactive substances. In patients with chronic nephrotic syndrome, proteinuria and TI pathology correlate with a bad prognosis. Associations at several levels have been proposed.

Oedema formation in the neohrotic syndrome -Why does sodium retention occur?

In 1917 Epstein recognised the close association between proteinuria, hypoproteinaemia and the development of oedema (1) . For a variety of reasons, most notably the recognition that in many cases of nephrosis the glomeruli looked normal by light microscopy, he subsequently pursued the possibility that alteration in the structure of plasma proteins might be the primary event in pathogenesis. This approach did not prove fruitful. The now traditional view was articulated by Bradley and Tyson in 1948 (2): proteinuria ~resulted from changes in the glomerular filter, hypoproteinaemia developed as a consequence, transudation of salt and water into the interstitium followed, oedema and a fall in plasma volume were the result. The fall in plasma volume led to activation of neural and humeral responses designed to preserve that volume, inducing the kidney -an innocent bystander in this regard -to retain sodium. Is this view correct?

In children with minimal change disease a clinical picture of hypotension, poor peripheral perfusion and relative polycythaemia is well recognised and is alleviated by volume expansion. In adults a picture of circulatory collapse, leading to acute renal failure or death, has been described and attributed to hypovolaemia in the absence of other obvious cause. In some instances the infusion of albumin into nephrotic patients has produced gratifying natriuresis and diuresis. These observations support the view that in some circumstances plasma volume may indeed be reduced in nephrosis, but is a tendency towards contraction of plasma volume a general mechanism driving renal sodium retention in the nephrotic state? The evidence is not compelling, and there is reason to believe that in nephrosis there may be an intrinsic renal avidity for sodium.

In the nephrotic individual actively retaining sodium the traditional hypothesis would predict, amongst other things, that plasma volume would be reduced (or possibly normal), that the renin-angiotensin-aldosterone system would be activated, and that inhibition of that system would tend to be natriuretic.

Measurement of plasma volume in the nephrotic syndrome is a difficult and controversial field. Interpretation of many studies is hampered by methodological imperfections and lack of attention to the need to make observations at a time of continuing sodium retention. However, the most meticulous work suggests that in adult nephrotics plasma volume is more commonly elevated than depressed (3) . In groups of sodium-retaining nephrotic patients activation of the renin-angiotensinaldosterone system is not a consistent tinding, and sequential studies of individual patients do not reveal a convincing relationship between the propensity to retain sodium and plasma levels of renin or aldosterone. Infusion of the angiotensin II antagonist saralasin or administration of the angiotensin converting enzyme inhibitor captopril do not induce natriuresis. These findings have led to dissatisfaction with the traditional hypothesis and to the suggestion that there might be an intrinsic renal abnormality of sodium excretion. Strong,direct evidence implicating an intrarenal abnormality has come from the study of an animal model. Puromycin aminonucleoside (PAN) acts directly on the kidney to induce heavy proteinuria, hypoproteinaemia and oedema when administered systemically to rats. [chikawa et al (4) used this property of PAN to create a unilateral model of the nephrotic syndrome. They perfused one kidney with the chemical, leaving the contralateral kidney as an unexposed control, Despite the fact that both organs shared the same systemic milieu, heavy proteinuria and reduced sodium excretion subsequently developed only in the kidney that had been exposed to PAN. Micropuncture suggested that the depression of sodium excretion resulted either from altered behaviour of tubule segments beyond the distal convolution, or from altered behaviour of deep nephrons inaccessible to surface micropuncture, Firth and Ledingham (5) examined the behaviour during isolated perfusion of the kidney taken from a rat rendered nephrotic by previous exposure to PAN. In this preparation the immediate influences of renal nerves and circulatory substances were clearly eliminated. Despite this the kidney of the nephrotic animal excreted considerably less sodium than a normal control at any given arterial pressure. The reason for this was not clear. The tendency to sodium retention was not overcome by high concentrations of ouabain, acetazolamide, frusemide, hydroflumethiazide, benzamil or atrial natriuretic peptide. An underlying metabolic abnormality was suggested by (a) the finding of increased oxygen consumption in organs taken from nephrotic animals, and (b) the observation that cooling to 8 -10~ rendered sodium handling by the isolated nephrotic organ virtually identical to that by similarly cooted control. degradation products, has been demonstrated (2,6). The fibrinolytic system has been little studied in nephrotic children.

Therefore, we analysed plasma levels of tissue plasminogen activator (tPA), the major protein of the fibrinolytic system, and its inhibitors (PAI), in 31 children with idiopathic nephrosis. The release of tPA from endothelium following ischemia (venous occlusion test) was studied in 4 cases. In addition, we studied plasma levels of D Dimers, presently considered as one of the most reliable criteria of prethrombotic states. At the time of blood sampling, mean plasma albumin level was 14 • 5 g/dl (4-23), factor V 165 • 44 % (~ 120 % in 90 % of cases), fibrinogen 6.1 • 2.2 g/l (~ 4.5 g/l in 77 %), AT III activity 75 • 33 % (< 70 % in 59 %). tPA antigen concentration (normal range : 3~i0 ng/ml) was < 3 ng/ml in 24 % of cases, PAl activity (normal range : 0-12.5 UI/ml) was > 12.5 UI/ml in 79 % of cases, and PAI-I antigen (normal range : 4-43 ng/ml) was > 43 ng/ml in 52 % of cases. In the 4 cases studied, decreased fibrinolytic activity, insufficient release of tPA and increased PAI activity were observed after venous occlusion. D Dimers concentration (normal < 400 ng/ml) was < 400 ng/ml in i0 out of 30 children (33 %), 400 to i000 ng/ml in 15 (56 %), 1040 to 5000 ng/ml in 5 (17 %). No Significant correlation was observed between plasma levels of tPA, PAI and D Dimers, and of albumin.

In conclusion, defect of tPA production and increased concentration of PAI may participate to the thrombotic risk in nephrotic children. Raised D Dimers levels confirm intravascular fibrin formation. Although no correlations could ever be established between coagulation anomalies aLd the occurence of thromboses, our attitude for prophylaxis is as follows : besides simple measures (mobilization, correction of hemoconcentration and hypovolemia by IV albumin), we recommend vitamin K antagonist treatment if plasma albumin level is below 20 g/l, with fibrinogen level over 6 g/1 and AT III level below 70 %. D Dimers levels over i000 ng/ml probably also have to be considered as a criteria for anticoagulant treatment. Questionnaires on enteral feeding in infants with severe CRF were sent to two other centers of Pediatric Nephrology. The following information was collected: primary renal diseases, age at start and duration of enteral feeding and its modalities; -type and duration of disorders subsequent to the end of tube-feeding -family attitude toward tube-feeding both at beginning and after it had been stopped. Data on 13 children with severe CRF (7 female and 6 male) were available. Mean age at start of tubefeeding:

12 months (range: 5 days-50 months). Average duration of enteral feeding: 21.6 months (range 9-32 mos.).

Nine children started before 1 year of age (mean age: 4.1 mos; SD 3.4) . Upon shifting to oral alimentation, 70 % of children showed important problems , which lasted always more than 6 months and, in 1 case, as long as 3 years.

The most common problems were incapability to chew and swallow. Tube-feeding may be necessary in a group of infants and children with CRF. However, the frequency and importance of subsequent disorders must always be considered before it is started.

is an aminoacid that is formed during muscolar catabolism.

It is not re-utilized and is excreted immodified in urine. Thfs excretion must increase during catabolic status. Two of the Authors previously demonstrated good correlation between 3-MeHis urinary daily excretion and 3-MeHis/creatinine ratio in a morning sample. This solves the problems of urine collection in infants.

In order to evaluate the effect of a low protein diet (70 % of RDA), we studied the variation of 3-MeHis/creatinine urinary ratio after the protein intake was modified from 100% to 70 % RDA, while energy intake remained substantially unchanged.

The study was carried out on a 10-month-old girl '~ with a creatinine clearance of i0 ml/min/l.73 sqm, who was still on a meat-free diet. This eliminated any possible bias for esogenous 3-MeHis. GFR remained stable thoroughout all the study. Two periods were identified: a control period in which a 100% RDA for energy and protein diet was suDDlied for one week, followed by an experimental period in which protein intake was reduced to 70 % RDA for one more week. Urine was collected in the last three days of each period. The study was repeated twice. No significant difference in 3-MeHis urinary excretion was observed during the two periods.

are not yet completely available, but preliminary data suggest that a catabolic effect is not induced by a diet with reduced protein intake. The control of serum phosphorus levels and the administration of active vitamin D sterol are the main agents utilized for the treatment and prevention of renal bone disease in patients with chronic renal failure.

At present, calcium containing phosphate binders and calcitriol are widely recommended for the control of renal bone disease in dialyzed children. However, hypercalcemia occurs in 20-30% of patients, therefore, aluminum containing binders are still required.

The recommended dosages of AIhydroxide are associated with the development of increased Al-body burden and therefore such agents must be used with caution.

In addition, the simultaneous administration of Al-containing binders and sodium citrate enhances intestinal A1 absorption and should not be used concomitantly.

Daily calcitriol therapy was associated with persistent or progressive bone disease in children treated with CAPD/CCPD. The intravenous use of calcitriol is impractical for CAPD/CCPD patients. We have performed pharmacokinetics studies with calcitriol after a single dose (4.0 ug/70 kg) given intravenously (IV), intraperitoneal (IP) and oral (PO) in 6 dialyzed patients. Such studies demonstrated greater bioavailability of the sterol after the IV route, but the area under the curve for calcitriol were not different between the oral and the IP routes; this was due to adherence of the sterol to the plastic component of the peritoneal dialysis system. By modifying the IP administration of calcitriol by direct instillation in the peritoneal cavity a greater bioavailability of the sterol was obtained. The longterm therapeutic implications of such manoeuver on the control of secondary hyperparathyrcidism remains to be determined.

In vitro studies suggest the "set-point" for calcium regulated PTH release is shifted to the right in parathyroid glands of patients with secondary hyperparathyroidism.

However, this issue has not been carefully evaluated in humans. We studied 13 dialyzed patients aged 15 • 2 yrs on peritoneal dialysis for 23 i 14 mos and 20 volunteers.

All subjects received a 2 hr intravenous infusion of ~aicium gluconate (2-8 mg/kg/hr) and sodium citrate (28-102 mg/kg/hr) on consecutive days to evaluate PTH response to changes in serum ionized calcium (iCa). Serum iPTH (IRMA) and iCa were measured at 30, 15 and 0 minutes prior to and every i0 minutes during infusions.

Sigmoidal curves were constructed by using the four parameter model. The set-point was calculated as the serum iCa necessary to achieve the mid-point between maximum and minimum PTH concentrations.

The set-point was 1.24 • 0.06 and 1.20 • 0.04 mmol/L, NS) in patients and volunteers respectively.

Serum iCa reached higher levels in normal volunteers despite identical infusion rates and PTH suppression occurred earlier in normal volunteers.

These findings suggest a difference in the sensitivity of the parathyroid glands to acute changes in iCa levels between dialyzed and normal volunteers.

Intermittent therapy with calcitriol has been shown io control secondary hyperparathyroidism in patients with end-stage renal disease. However, the difference between the different routes of calcitriol administration on rhe control of PTH secretion remains to be determined. We have randomly assigned 21 patients aged xx • xx to either oral (PO, n=9} or intraperitoneal (IP, n=12) calcitrisl therapy.

All patients have bone biopsy proven secondary hyperparathyroidism.

Calcitriol was given at initial dose of 1.0 ug in both treatment groups thrice weekly in the morning.

Calcium carbonate was the main phosphate binder and the dialysate calcium level was 3.5 mEq/L. Serum Ca, PO4, Alk. P'tase and PTH (IRMA) were measured before treatment and at monthly intervals thereafter. After 4 months in the study, S-Ca levels increased from 9.1 • i.i to 9.7 • 1.0 mg/dl (p <0.05) in the IP group and from 8.9 • 1.2 to 9.3 Z 1.2 mg/dl (NS) in the PO group.

S-PTH levels decreased by 44 f 86% from baseline (p <0.05) and S-Alk. P'tase decreased by 35 • 29 % (p <0.05) in the IP group respectively.

On the other hand, PTH and Alk/ P'tase levels did not change from baseline in the PO group. These preliminary observations suggest that IP calcitriol is more effective than PO for the control of secondary hyperparathyroidism when given in similar dosage thrice weekly in dialyzed children.

However, further long-term follow-up is warranted. Uremia is a condition for resistance to growth hormone (GH). The GH production rate from the pituitary gland is normal when calculated by the deconvolution method from the growth hormone serum night profile. But, renal metabolic clearance rate of GH, measured by steady state infusion technique, is significantly reduced in children and adults with chronic renal failure (CRF). This results in an increased serum half life of GH and an elevated integrated serum~ GH concentration.

Although the GH serum concentration is high, the action of GH at the target organs is, at least partially, diminished. This seems to be the consequence of a reduced availability of IGF-I, which acts as mediator substance of GH: In uremia, the high-affinity GH binding protein (GHBP) activity in the circulation is reduced. GHBP most likely reflects the receptor status for GH at target organs, and one might conclude that it is low in uremia. In accordance with this view, we have found a reduced mRNA concentration of the GH receptor in liver tissue of uremic rats. As a consequence, the renal production rate of IGF-I is found to be reduced in uremic rats and men. In addition, the serum concentration of the main carrier protein of IGF-I, IGFBP-3 is increased as a consequence of the reduced renal clearance of the low molecular fragments of IGFBP-3. Low production rate and high binding capacity of IGF-I result in a reduced availability of free active IGF-I indicated by a low bioactivity of IGF-I in uremic serum. The resistance of GH can be overcome by the treatment with recombinant human (rh) GH in doses of about 1 IU/kg/week. In prepubertal children with CRF, without or with dialysis treatment, rhGH significantly increases growth velocity. This effect is most expressed during the first treatment year but, a significantly higher growth velocity in comparison to the pretreatment growth velocity is also seen during the following treatment years. While oxygen is vital to aerobic cells, some metabolites of oxygen are toxic to cells. These reactive oxygen metabolites have been recently suggested to mediate the pathophysiological processes of a wide spectrum of renal diseases, including acute tubular necrosis, glomerulonephritis, nephrotic syndrome and progressive renal failure. Thus, investigators observed a protective effect of antioxidants when they were given exogenously in a number of experimental settings. Of note, in this regard, manifestations of a particular disease are determined by the dynamic balance between the pathogenic insult and the host's defense mechanisms. To determine the functional importance of intrinsic antioxidant .enzymes (AOE), therefore, we conducted a series of studies. Our early studies indicated 1) that exposure of the kidney to a short-term ischemiareperfusion leads to an acquisition of a significant renal resistance against reperfusion injury by raising AOE activities, whereas 2) ECF volume depletion, by depressing the AOE activities, predisposes the kidney to nephrotoxic injury, e.g., one with contrast medium. To further scrutinize the functional significance of the regulation of intrinsic renal AOE systems, we have recently conducted a series of in vivo and in vitro studies focusing on the therapeutic mechanism of glucocorticoids in oxidant-induced renal injury.

In vitro studies demonstrated that significantly higher than those in untreated controls, while glutathione peroxidase activity was unaffected. Northern blot analysis using a bovine Mn-SOD cDNA probe revealed that Mn-SOD mRNA was increased 4-7 fold in MP-treated cells over that in untreated controls. When these cells were exposed to superoxide anion by incubating cells with xanthine + xanthine oxidase, the levels of specific membrane lipid peroxidation products, i.e., phosphatidylcholine-, and phosphatidylethanolamine-hydroperoxides in MP-treated cells were only 10-25% those of controls. Moreover, the degree of cell damage following incubation with X + XO, assessed by 51Cr release, was significantly and substantially attenuated in MP-treated cells.

In summary, the increase in AOE was found in the protected lesions of the animal model of minimal change disease. Increased AOE could be identified in cultured glomerular cells which were protected. Inoculation of AOE produced a similar protection in experimental animals. Increased AOE could be demonstrated in the protected lesions of these animals.

The results therefore indicate that glucocorticoid induces functionally important antioxidant enzymes within the glomerulus. The capacity of glucocorticoid to induce antioxidant enzymes may underlie its well-known anti-inflammatory and anti-bacteriocidal actions.

Sequence analysis of Mn-SOD DNA revealed that within the regulatory region immediately upstream to the coding exon there is at least one sequence relevant to the core exanucleotide consistent with the glucocorticoid response lesions of these animals.

The results therefore indicate that glucocorticoid induces functionally important antioxidant enzymes within the glomerulus. The capacity of glucocorticoid to induce antioxidant enzymes may underlie its well-known anti-inflammatory and anti=bacteriocidal actions.

Sequence analysis of Mn-SOD DNA revealed that within the regulatory region immediately upstream to the coding exon there is at least one sequence relevant to the core e• consistent with the glucocorticoid response element, indicating that the glucocorticoidinduced upregulation of Mn-SOD activity involves enhanced transcription of the Mn-SOD gene. Systemic lupus erythematosus (SLE) is a classical immoral mediated autoimmune disease with multifactoriai etiology. Several animal models of SLE exist in which the disease is induced, among others, by genetic factors (NZB/W, MRL/lpr, BxSB). We herewith report the induction of experimental SLE in naive mice by active immunization with pathogenic anfi-DNA idiotype (i6/61d) (PNAS 85:2260, 88, J. Autoimmun~ty: 1; 683, 88). The disease is characterized by accelerated ESR, leukopenia, proteinttria, alopecia, production of autoantibodies such as anti-ds DNA anti-cardiolipin and anti-SM and glomerular immune complex deposit!on entailing mouse 16/61d.

The disease was induced also by immunization with anti-16/61d Ab (Eur J. Immunol 19: 729, 89), by other antoantibodies carrying the 16/61d (Stand J Immunol 31: 45, 90) and with transfer of Th cell lines reacting with 16/6 (Clin Im ImmunopathoI 60: 471, 1991).

Monoclonal antibodies generated from mice with the experimental SLE were employed to generate SLE (Int. lmmunol 2: 225, 89) and anti-phospholipid syndrome (PNAS 88: 3069, 91) production has been found to be associated with lower GFR (J.C. I. 1986 ,72,1439 -Fed,Proc. 1983 ,,42, 3058-A.J.P. 1986 251.F581-K.I. 1986 . By blocking the TXAz synthesis or effects it is possible to ameliorate the renal function, at least partially (Prot Leukot Mad, 1986 ,21,29, J.C.I,1983 ,72, 1439 -A.J,P. 186, 251, F581-A,J.P. 1986 ,250,F282 -J.C,I. 1985 ,75,1242 . It must be mentlonned that the actions of TXAa do not seem to be limited only to GFR but also to macromolecules permeability and progression of glomerular damage. Increased in glomerular TXAz may be associated with increased proteinuria (A.J.P. 1987 ,128, 45 -Clin Nephrol, 1988 ,30,276-J.C.I. 1985 The price land mammals pay for the ability to concentrate their urine is a renal medulla that is perpetually hypoxic. Two factors are responsible for the poor oxygenation of the renal medulla; first, as a byproduct of the countercurrent mechanism that permits solutes to be concentrated along a codicopapillary gradient, oxygen diffuses directly from the descending to the ascending branches of the vasa recta. Second, in this region, lhe medullary thick ascending limb of Henle's loop (mTAL) avidly consumes oxygen for sodium chloride transport, necessary for the generalion of concentration gradients. The net result is that the pO 2 in the depths of this region falls to very low levels, in the range of 10 mmHg. In this hypoxic environment, cells of the toTALs are particularly susceptible to excessive workload and may be a prime target of injury in renal insults. By contrast, in the cortex, glomerular filtration and bulk reabsorption of solute along the proximal tubule are supported by an exceptionally generous blood flow, which equals nearly a quarter of the total cardiac output. As the result of high tissue perfusion, over the metabolic needs of tubules, cortical pO2 is generally high, averaging 50 mmHg. In this region, however, the medullary rays (which are expansions of the renal medulla into the codex) receive a substantial portion of their oxygen supply from desaturated blood ascending from the renal medulla and may also be particularly vulnerable to hypoxic injury during renal hypoperfusion.

Medullary oxygen balance appears to be regulated by multiple paracdne homeostatic mechanisms. For instance, prostaglandin E2, released by the renal medulla in response to regional hypoxia, induces local vasodilatation and reduces transpod work by the toTAL, thus reestablishing medullary oxygen balance. Likewise, adenosine, liberated from the breakdown of cellular ATP in circumstances of deficient oxygenation, acts upon intrarenal adenosine receptors to increase medullary blood flow while decreasing GFR and distal solute delivery (a major determinant of reabsorption workload in mTALs), thus restoring medullary oxygen sufficiency. Local release of the endothelial-derived relaxing factor nitric oxide may also play an important role in assuring a basal active medullary vasodilation. Interference with these paracrine mechanisms may predispose to focal hypoxic injury at sites of strategic importance for overall renal function.

Hypoxic injury to tubular cells represents an earliest event in acute renal failure. Although important advances have been made at the cellular level in understanding hypoxic injury (e.g., loss of cell polarity, production of free radicals, calcium entry and the activation of genes for protection or regeneration), the basic mechanisms responsible for organ failure remain elusive. The renal medulla, working on the brink of anoxia and site of concentration for many toxins, may be an important target for the synergistic events of hypoperfusion and nephrotoxic exposure that almost invadably precedes human acute renal failure. The renal structures most at risk for hypoxic damage in vivo are the thick ascending limb and the straight portion of the proximal tuhulP. (in the n.t~r medu!!~ ~qd in. the medullary rays). Injury to the Henle's loop may be padiculady detrimental to renal function, because of activation of tubuloglomerular feedback (there is little chance for correcting deficient salt reabsorption between the mTAL and the macula densa) and because of intraluminal obstruction by cast precipitation of Tamm-Horsfall protein, exclusively released by damaged toTALs.

The synergism between renal hypoperfusion and toxic insults derives from several factors including increased intrarenal concentration of toxins, drug interference with renal protective mechanisms, coprecipitation of Tamm-Horsfall protein with toxins (such as Bence-Jones protein, myoglobin or contrast material), enhanced tubuloglomerular feedback, and synergy at the cellular levels such as increased oxygen demand by toxic membrane damage and toxic-induced mitochondrial dysfunction. Renal medullary hypoxia may play an important role in the susceptibility of the kidney to acute renal failure from synergistic hypoxic and toxic insults Recent developments during the past decades point to an important role of locally acting factors in the regulation of cell growth, inflammatory responses and kidney function. These factors are produced locally, e.g. they act near their sites of synthesis at specific receptors ("local hormones"). They act either I~y an autocrine, paracrine, or as intracrine mechanism. Up to now there is no generally accepted cla.~sification of locally acting factors, but besides eicosanoids (prostaglandins, leukotriens), histamine, bradykinin, the large group of growth factors and endothclin belong to that group. Circulating hormones can be measured in plasma, often simply be immunological methods and in general rite concentrations measured represent their biological activity. Therefore studies in man are possible and valuable. However, it is not clear, whether this statement is also true for locally produced and locally acting factors. One can speculate that measurements of locally produced and locally acting factors in plasma or urine does not represent their biological significance. Therefore, the production, biological effects and their responses via binding at specific receptors has been elegantly studic~ in cell culture systems. Studies in patients are more difficult, particularly from a methododieal point of view. Endothelin 1-21 (ET-I) belongs to a family of locally produced regulatory peptides with potent vasoconstrictor activity. In the kidney ET-1 exerts profound effects, e.g. increase in vascular resistance, decreases in glomerular filtration rate and renal plasma flow, and decrease in sodium reabsorption via reducing filtered load and through inhibition of Na*-K*-ATPase. Besides these potent renal effects ET has been discussed as an important factor in the pathogenesis of glomerular inflammation, cyclosporine ncphrotoxicity, and postischemic renal injury (1) . It has also been suggested that ET-I mediates hemodynamically induced acute renal failure (2) . Elevated urinary excretion of ET has been reported in patients with renal diseases (3) and in children with hemolytic uremic syndrome (4) . To study the biological significance of ET-1 in children with renal disemses, we measued urinary ET-1 excretion using a specific antibody to ET-1 (RPA 555, Amersham, Braunschweig, Germany). Urinary ET-I excretion in 60 children and adolescents averaged 0.46+0.13 pmol/kg body weight per day (mean_+SD). It was constant during childhood and adolescence (4-8 year, n:20, 0.49+0.13 pmol/kg per day, 9-12 years, n:20, 0.44+ 0.12, 13-18 years n:20, 0.45_+0.15. Compared to these normal controls elevated urinary excretions of ET-1 were found in children with idiopathic hypercalciuria (n:7, 1.72_+0.83 pmul/kg per day, chronic renal failure (n:14, 1.30+1.08), and following renal transplantation (n:8, 1.00+ 0.56; all groups P<0.01). However, ET-I excretion was unchanged in children with idiopathic steroid sensitve nephrotic syndrome (n: 0.33+0.19) and with stable chronic giomerulonephritis (n:8, 0.39-+0.14). ET-1 was elevated in two children with hemolytic uremic syndrome (3.95 and 0.88 pmol/kg per day). Urinary ET-I concentrations were similar in controls and in various patient groups. ET-1 excretion correlated positively with urine flow rate in normal controls (r: 0.70) and in all patients studied (r: 0.85). Eight healthy volunteers (23-27 years old, 4 female, 4 male) were studied before and after oral water load (20 ml/kg) to investigate the effect of ET-I excretion on urine flow rate. Urine was collected following overnight dehydration and 2 and 4 hours after water load. Urine flow rose tenfold in response to water load and urine concentration of ET-I fell only by 60% (from 27.3+5.3 fmol/ml to 10.1+ 2.6 fmol/ml after 2 h, and to 10.7-+4.5 fmol/ml after 4 h). ET-I excretion rose from 11.1+4.7 fmol/kg per h to 53.2 _+16.8 and 40.3_+13.8, respectively. These results indicate that urinary ET-1 excretion depends at least in part on urine flow rate. This is in contrast to earlier results (3) . Therefore the interpretetlon and the biological significance of elevated ET-1 excretion in renal diseases is difficult. References: Rfldiqer Waldherr De~t of Pathology~ University of Heidelberg, Im Neuenheimer Feld 220, D-6900 Heidelberg, ~y Cytokines and growth factors are supposed to play an important role as mediators of inflanm~tion and as progression factors in various renal diseases. Most studies on the expression of cytokines~ growth factors and their receptors in the kidney have been performed in animals, particularly rodents, and in call culture experiInents. However, the extrapolation of these findings m~st be interpreted with caution and it is difficlllt to know to what extent these results are applicable to humans in view of the well-known species differences. The only possibility is to examine biopsy tissue. Although the apparent shortcomings and limitations of investigating renal biopsies are the facts that only a certain stage of the disease can be evaluated phenotypically and early lesions are frequently missed, it is absolutely necessary to validate experimental results in human material. We therefore looked for the expression of some these factors in kidney biopsies from patients with allograft rejection, mesangial IgA-glomerulonephritis (IgA-GN) and ANCA-positive (anti-neutrophil cytoplasm antibodies) GN (Wegener's diseasef microscopic polyangiitis) by means of irmm/nocytochemistry (using polyclonal or monoolonal antibodies), in situ hybridization (using radioactive labelled riboprobes) and the polymerase chain reaction (PCR). Allograft biopsies from 45 renal transplant patients were classified into three groups according to clinical and histological criteria: acute cellular rejection (ACR; n=25), chronic rejection (C~rR; n=8) and no rejection (NOR; n=12). Numerous infiltrating calls expressing IL-I$, TNF-~, TNF-#, IFN-y and IL-2Rec (Ii-2 receptor) were detected in all cases of ACR, whereas in patients with NoR or with ChrR only sporadic cells were noted. A marked immunoreactivity of Ii-2 was observed in mononuclear infiltrating calls in ACR. In contrast, Ii-2 positive calls were only occasionally detected in C~lrR and constantly absent in NoR. TNF-Rec and IFN-yRec were expressed by interstitial mononuclear cells as well as by glomerular and arterial e/idothelium in cases with ACR, and to a minor degree in NoR and in C~rR. The strong i~m,,~nostaining of IFN-TRec in tubular epithelium correlated with the neoexpression of MHC class II antigens. PDGF (AB, BB), PDGF-~Rec and TGF-B irmm/noreactivity was observed in infiltrating calls, fibroblasts and arterial endothelium. In addition, in C~R a marked staining of myofibroblasts was observed in arterial vessels. The results obtained at the protein level were confirmed by hybridizing tissue sections with 55Slabelled IL-I~, TNF-a and PDBF-~Rec riboprobes. Our findings indicate that a scenario of cytokines and growth factors is produced in situ in ACR reflecting marked inmmLnological activation. IL-2 seems the most reliable marker to differentiate ACR from other abnormalities. The low detection of these factors in NoR suggests that even in the absence of ACR a silent ~ological process may operate. The strong expression of PDGF and TGF-~ in ChR indicates that both factors play a pivotal role in the development of vascular lesions. In IgA-(IN (n=30), an increased mesangial PDGF-AB/BB reactivity was present in 17/30 cases. Cor~pared to the constitutively low expression of PDGF-~Rec on mesangial calls in normal renal tissue (n=5), we detected a markedly increased positivity in cases with mesangial proliferation. No change in the expression of PDGF-~Rec was observed. Mesangial expansion was associated with an increased expression of TGF-~, particularly of TGF-~3, and IL-6. TNF-o, IL-I~, IFN-y, IL-2, IL-2Rec and IFN-u positive interstitial cells were only occasionally noted in a few cases. Tubular IFN-yRec expression correlated with ~C class II positivity. These results suggest that PELF, TGF-~ and IL-6 may contribute to the development of mesangial proliferation and sclerosis in IgA-G~. In ANCA-positive GN (n=32), cases with active lesions (crescents, necroses, infiltrates, acute vasculitis) disclosed numerous infiltrating calls positive for TNF-~ and IL-I# at these sites. The production of the cytokines in situ was confirmed by in situ hybridization and PCR of the remaining biopsy tissue (n=6). TNF-Rec was expressed by infiltrating calls and endothelial calls of interstititial capillaries and larger vessels. Interstitial infiltrates were also positive for IL-2Rec, IFN-?, IFN-yRec, TGF-~, PDGF and PDGF-~Rec. PDGF and TGF-B reactivity was increased in endothelial calls. In contrast, patients with inactive or scleresing lesions showed only scattered positive calls. We conclude that the production of these cytokines in situ plays an i~rtant role in the induction of the inflarmnatory process and the development of the histological lesions in ANCA-positive GN.

S-17.3

Several growth factors with stimulatory or inhibitory effects on proliferation of renal epithelial and mesangial cells have been reported. We selectively focus on EGF and TGF-8, which, based on cell culture and animal studies, appear to have particular importance in glomerular cell proliferation or stimulation of extracellular matrix synthesis.

Glomerular expression of those growth factors and the role in human glomerular diseases were studied using immunocytochemical techniques and in situ hybridization. EGF EGF (6 kD polypeptide) and EGF-receptor(EGF-R) have been identified in a number o~ normal human tissues and human malignancies. Human EGF is derived from a 12 kD precursor, prepro-EGF. Studies by Salido et al. (1) have shown that prepro-EGF mRNA and EGF are predominantly localized to the thick ascending limb of Henle and the distal convoluted tubules in animals' kidney. We demonstrated the glomerular localizatiofi of EGF and EGF-R in normal and nephritic human kidneys (2) . By radioimmunoassay, EGF-immunoreactive material was 3-to 5-fold higher in the glomerular fraction than in the tubular fraction obtained from normal human kidneys. Immunofluorescence and immunoelectron microscopy with a monoclonal antibody revealed EGF was localized along the glomerular capillary walls in some of tissues from normal subjects and patients with proliferative or non-proliferative type of glomerular diseases.

In some tissues, EGF was detected only after pretreatment with acid-urea (3) to unmask a hidden epitope.

EGF-R was occasinally co-localized with EGF. There was no obvious difference in EGF and EGF-R expression in glomeruli derived from normal or diseased state.

Expression of TGF-BI in normal and diseased human kidneys was examined by immunohistochemical staining and in situ hybridization.

The presence of mature TGF-B along the glomerular basement membrane (GBM) and in the mesangium was revealed after acid-urea treatment of the tissue sections. The latency-associated peptide (LAP) of natural TGF-B was localized to mesagnium, sclerotic areas and immune deposits of nephritic tissues. Mesangial staining of TGF-B-LAP was significantly correlated with the mesangial matrix increase in mesangial proliferative types of glomerulonephritis.

In situ hybridization revealed TGF-~I mRNA expression by glomerular cells.

The cells with positive signals were numerous, compared with intraglomerular monocyte-macrophages which were identified with a monoclonal antibody. These data suggest that, in line with the observation in experimental nephritis (4), glomerular expression of TGF-B is enhanced in human glomerular diseases, and may contribute to the mesangial matrix increase.

S-17.4

An aberrant renal dooaminergic system may dlay a role in the oathogenesis of some forms of hyDertension because some forms of hypertension are deoendent or agpravated by so]ium loading and because DA is imoortant in aiding the oroanism to eliminate "excess" sodium. In normotensive animals, the natriuretic effect of DA is due to both hemodynarlic and tubular factors. '!hen intrarenal 9A subserves a paracrine function at renal D I receotors, the natriuretic action i~ nrobabIv due entirely to its tubular effects by inhibitii~g Ha+F1+'exchange and!!a+/X + ATPase activity in sqecific neDhron se9ments. These actions are meaiated by second messengers generated as a conseouence of stimulatory actions on adenylyl cyclase (AC), nhosnholi~ase C and ohosnholiDase A 2 activities.

Both human and animal models of hyqertension are renorted to have decreased renal qA nroduction and/or oost-first messenger defects. The Dahl salt sensitive rat, x.!hich has a decreased ability to generate renal DA and the spontaneously hypertensive rat (SHR), !vhich has no such limitation, have a defective coupling of a DI receptor to a G protein/AC comolex. This coupling defect is: (1) genetic~since it is present before the onset of hypertension and co-segregates with the hypertensive ohenotyoe (2) receptor sQecific since it is not shared by other humoral agents (3) organ and neohron segment selective since it is found in proximal tubules but not in cortical collecting ducts or in the brain striatum. A consequence of the defective DA receptor/AC couolina in SHR is a decreased ability of D I agonists to inhibit'Na+/H + exchange activity and a resistance to the natriuretic effect of DA and D 1 agonists. This resistance in SHR is due mainly to a decreased cAMP oroduction, although with maturation, a ~ost cA!IP defect is acquired.

Since the defect in cAMP nroduction or sodium transport in SHR is not due to "defective" G-binding protein or enzyme response, Ire have initiated studies to determine if a renal D 1 receotor is abnormal. A high and low affinity D I binding sites are seen in normotensive rat (!!KY) but only a lo!~ affinity binding site is seen in membrane bound or solubilized receptor of SliR. The affinity of DA aqonists to their recentor is decreased in SHR ~qith some chemical classes having a greater reduction in their affinity than others. Renal proximal tubular D 1 receptor(s) of SHR is also resistant to alkylation of sulfhydryl grouos. Hoelever, no mutation has been demonstrated in the sequence (3rd loon to the carboxyterminus) of the two DA recentor genes linked to AC stimulation (DIA and ~IB) that are expressed in proximal tubules.

Conclusion: There is defect in a D I receptor-linked to AC stimulation in the renal proximal tubule of SHR. !!hether the defect is in the nrimary or tertiary structure of the receptor remains to be demonstrated. The long term outcome of 221 consecutive kidney grafts performed from 1973 to the 1 st january 1982 in the Enfants Malades hospital is reported in this study. For this cohort of patients graft survival was 48% at 10 years and 35% at 15 years. Patient survival was 85% at 10 years and 70% at 15 years. Presence of cytotoxic antibodies against more than 50% of the panel, and poor HLA matching was associated with a lower graft survival. One hundred and six patients had a functioning graft after 10 years, but on the 1 st january 1992, there were only 83 remaining, 22 other patients had another graft functioning again, 48 were waiting a second or a third graft on dialysis, 49 died and 12 were lost to follow up. Focusing on the 106 patients who had a functioning graft after 10 years, 14 went back to dialysis in the following years and 9 died (2 cancers, 2 hepatitis cirrhosis, 2 cystinosis, 1 septicemia, 1 pancreatitis, 1 cause unknown). At last examination 10 to 19 years after grafting 68% of the 83 functioning graft had a s. creatinine < 120 i.tmol/I, 20% between 120 and 250 and 11% > 250 ~tmol/l. Forty one patients had a graft biopsy after 10 years, 17 of them had glomerular lesions (11 allograft nephropathy, 4 recurrent MPGN and 2 de novo membranous nephritis), 26 had normal parenchyma or mild interstitial fibrosis and 19 normal vessels or mild arteritis. Several kinds of complications occured in patients after 10 years of grafting, they were mainly related to the i. s. treatment. Bone complications were related to corticosteroid : osteoporosis was detected in 34% of patients on X rays, but according to densitometry 46% patients had severe osteoporosis and only 17% might be considered to have normal bone density. Bone osteonecrosis was observed in 22 patients, 3 of the 11 with femoral head necrosis needed a surgical prothesis, but the incidence of this complication decreased after 1978 date of a decrease of corticosteroids in the protocol. Infectious complications were rather rare : 7 urinary tract infections + pyelonephritis, 2 salmonellosis, 2 septicemia, 1 otitis, 1 lung tuberculosis, 4 cutaneous mycosis, 5 herpes zoster, 2 varicella and 2 CMV infection were observed in 284 patient/year. B hepatitis was a matter of concern in these patients, 31 of 106 were HBs positive 10 years after grafting, 19 of them with Hbe antigen present, at last examination 17 had persistant cytolysis, 10 of 11 who underwent a liver biopsy had severe lesions, 1 had portal hypertension, 2 died from liver failure and 1 from hepatocarcinoma. The other patient with a malignancy died from a bladder sarcoma following the long term prescription of cyclophosphamide. C hepatitis serology was positive in 9 of 85 patients, 8 of the 9 were also bearing HBs antigen and only 2 of these patients had silent hepatitis. Late urological complications were rather rare : 9 had a lithiasis and 1 had an ureteral stenosis. A nervous break down was observed in 4 patients and 1 of them attempted suicide. A particular mention has to be made about the 12 patients with cystinosis who developed different extra renal complications of the disease (4 encephalopathy, 5 diabetes, 1 portal hypertension). The mean adult height of these patients was 155,7 cm _+ 10,1 in male, and 149,5 cm _+ 9,5 in female that is to say -3 SD and -2,2 SD respectively. Rehabilitation study showed that of the 106 patients who reached 10 years of grafting 43 had a full time employment, 5 had a part time or at home job, 31 were continuing studies or vocational training, 18 were unemployed and 9 were unable to work. Of the 83 patients with informative data on this point, 43 were living in their own home, of whom 22 had a marital life, while 38 were living with their parents and 2 in institution. Ten children were born from mother or father with a functioning graft and except for prematurity, these children now 1 to 9 years old are developing normally. Considering the clear improvement in patient survival during the last decade and the progresses in prevention and treatment of complications, the long term results of kidney transplantation in children will brobably improve in the future.

S-18.2

The effect of pre-transplant transfusions on graft survival in patients treated with cyclosporlne is controversial. Graft survival rates in 66 children in out center who received living related donor transplants (LRT) after donor-specific transfusions (DST) and were treated with prednisone and azathioprine were 74% and 60% at 5 and 10 years, respectively. Subsequently, 21 children received LRT after DST and were treated with , sequential therapy including cyelosporine; graft survival at 2 years was 85%. These results are no better than those obtained in children treated with eyelosporine and no DST in other centers. A beneficial effect of either DST or random donor transfusions on graft survival in recipients of 1-haplotype LRT treated with cyclosporhae was noted in one large multicenter study (South Eastern Organ Procurement Foundation), but not in another (Collaborative Transplant Study).

The effect of transfusions on cadaver graft survival was evaluated in three large studies. The differences in 1 year graft survival rates between transfused & non-transfused patients treated with cyclosporine were 7%, P<0.01 (UCLA Transplant Registry), 5% P<0.001 (UNOS Registry Data), and 3%, P<NS (Collaborative Transplant Study). There was no transfusion effect in patients in the UCLA study who received grafts with no mismatches at the DR locus. The data suggests that transfusions exert a slight beneficial effect on cadaver grafts survival but little or no effect on living related graft survival. Preformed natural antibodies (PNA) against donor-incompatible blood group antigen(s) represent the major barrier against ABO-incompatible human organ transplantation. Kidney as well as heart allografting across major ABO-incompatibility leads to rapid loss of the transplant from vascular rejection in the vast majority of cases. However, this is not always the case: Starzl et al. reported the case of a group B to groupAliving donor kmdney still perfectly functioning 24 years later.

It is a well known phenomenon that the PNA titer drops after ABO-incompatible transplantation due to binding of these antibodies in the graft; they reappear in the circulation after graft nephrectomy when binding in the transplant is no longer possible. Indirect immunofluorescence studies clearly demonstrate binding of these PNA on endothelium of the glomeruli and peritubular capillaries of the kidney. This leads to endothelial swelling and mononuclear and polymorphonuclear leukocyte adherence to the endothelium of the glomerular and peritubular capillaries as a primary step to intravascular coagulation and thrombosis of these vessels.

Preoperative elimination of the PNA from the recipient's serum is therefore a prerequisite for successful AB0-incompatible renal transplants. The most effective procedures to accomplish this are plasmapheresis and/or immunoadsorption.

Some investigators believe that A2 to 0 cadaver renal transplants are at minor risk compared with A1 to 0. Bowever, the results obtained in this subgroup do not confirm this hypothesis.

In the experience performed at the Cliniques Bniversitaires Saint Luc in Brussels, thirty seven patients received 38 ABO-incompatible renal silografts (one patient received 2 A~0 inco~,,patib]e kidney transplants successively). All patients received living donor kidney transplants except the first who inadvertently received an ABO-ineompatible cadaver graft. The source of the living donor transplants was the mother in 19 cases, the father in 8 cases, the spouse in 7 cases~ a sister in 2 cases and an uncle in 1 case.

The donor-recipient ABO incompatibilities were A1 to o in 16 cases including the cadaver transplant A2 to 0 in 4 cases, A1 to B in 4 cases, B to 0 in 9 cases, AIB to B in 1 case, A3B to B in 1 case, AIB to A1 in 1 case, AIB to 0 in 1 case and B to A1 in 1 case.

Plasmaphereses were performed preoperatively on days -5, -2 and -1 in all the patients but the first one who received a cadaver graft. Immnnodepression in the first cases was achieved with a triple drug therapy consisting of ALG, Imuran and Steroids. Thereafter some patients received a triple drug therapy consisting of ALG, Csa and steroids while in the last series, a quadruple drug therapy was used consisting of ATG, Csa, Imuran and steroids.

The overall results are better in the series of related living donor transplants, the best results being obtained in the 18 cases of mother to child kidneys. Some patients are now approaching I0 years graft survival.

All long-term functioning ABO-incompatible transplants retain their function nothwithstanding the presence of specific isoantihodies directed at the ABO antigens of the graft endothelium, a phenomenon to which we called specific attention and for which F.H.Bach proposed the name of "accommodation". This phenomenon bears important prospects for the possible solution of the xenotransplantation problem where the barrier also consists of natural preformed antibodies in the recipient against the donor species in discordant xenotrsnsplants. 15-deoxyspergualin is a guanine derivative which acts primarily on accessory cell function in the immune response. It has been shown to successfully reverse acute rejection episodes. Prostaglandin analogs inhibit T cell mitogenesis, IL-2 production, and cytotoxic T cell activity.

A randomized double blind study found that misoprostol in combination with CsA and prednisone improved human renal transplant function and reduced the incidence of acute rejection. Lipooxygenase inhibitors inhibit T and NK cell activity. Experimental studies suggest that they may be effective in reducing rejection activity. Other agents that may have efficacy include ieflunomide and azaspirene. The latter produces effects similar to total lymphodial radiation, specifically induction of non-sDecific suppresser cells. Bioloqical immunosuppressive agents include both polyclonal and monoclonal (Moab) antibodies.

The Moab OKT3 has been in general use for more than I0 years. OKT3 reacts with the CD3 epsilon component, and is quite effective in abrogating rejection.

Its side effect profile, resulting from T cell activation and lymphokine release, is quite significant.

New Moabs are being developed. TIOB9 and BMA031 are Moabs directed against the T cell receptor rather than the CD3 complex and are effective in both rejection reversal and induction therapy.

Their side effect profiles are mild.

Other Moabs with promise include those directed against subsets of T cells, such as those against the IL-2 receptor on activated T lymphocytes, or those against the CD4 antigen on the helper-inducer subset of T cells. A Moab against tumor necrosis factor alpha significantly decreases the side effect profile of OKT3, and may be immunosuppressive as well, by decreasing the production of other lymphokines.

Moabs directed against accessory adhesion molecules such as the intercellular adhesion molecule-i (ICAM-I) also has promise in abrogating rejection.

Moabs may also be used to profuse renal allografts at the time of surgery; antibodies against the leukocyte common antigen (CD45) result in significantly less allograft rejection in pilot studies.

It is likely that combinations of new pharmacological and biological agents may result in markedly improved immunosuppression and possibly even tolerance with minimal side effects.

S-19.1

In patients not differentiated by age of onset of IDDM the incidence of diabetic nephropathy (DN) rises dramatically from the lOth to 15th year following onset of diabetes. However, given the same duration of IDDM, the prevalence of DN is less in patients whose age of onset of IDDM is before as compared to after puberty. This difference is not seen when patients are matched for post-pubertal duration of IDDM or for attained age. A similar relationship to age of onset of IDDM holds for the prevalence of diabetic retinopathy. These observations have suggested that the prepubertal years of ]DDM may be protected from the development of microvascular complications such as nephropathy and retinopathy.

To assess the impact of age of onset of IDDM on glomerular structure we compared these morphometric parameters in renal biopsy specimens from two groups of diabetic patients (groups 1 and 3) with similar duration of IDDM but with age of onset of IDDM before vs after 15 years: glomerular basement membrane (GBM) width, mesangial volume fraction (VvMes), and periperal GBM filtration surface density (SvPGBM). The duration of IDDM was the same in each group, 9-15 years (12+2"), but the age of onset of IDDM was before age 15 in group 1 (4.55:3 years) and at or after age 15 in group 3 (23.65:4 years). None of the IDDM patients had microalbuminuria or any laboratory or clinical features of DN. Data from each diabetic group was compared with control values (groups 2 and 4) derived from normal donor kidneys matched with the IDDM patients for age at time of biopsy. "p--<0.03 vs age-matched controls Patients in each of the diabetic groups developed a comparable increase in GBM width and VvMes. These data suggest that age of onset cf IDDM does not impact on the development of critical glomerular lesions of DN such as increased mesangial volume fraction; moreover the data do not provide a nephropathologic basis for the apparent protection of the prepubertal years from development of the microvascular con-olication of diabetic nephropathy.

S-19.2

Clinically apparent diabetic nephropathy is defined as overt proteinuria, hypertension, and declining glomerular filtration rate. Overall effects of diabetes on the kidney begin very early in the course of diabetes and include increase in kidney size, increase in glomerular filtration rate (GFR), increase in protein excretion, and morphologic changes. The increase in GFR can be seen at the onset of diabetes and improves with insulin therapy but tends to remain about 20% above normal until onset of clinical nephropathy begins when GFR begins to fall. Overt proteinuria is defined as dipstick positive proteinuria and is roughly equivalent to urinary albumin excretion 250mg/24 hours. Prior to the onset of overt proteinuria, many invetigators have defined a stage of microalbuminuria where the urine dipstick remains negative but albumin excretion is above the normal. It has been suggested that microalbuminuria can predict later onset of clinical nephropathy.

The classic morphologie changes of diabetic nephropathy are nodular and diffuse glomerular sclerosis by light microscopy. Glomerular basement membrane (GBM) width on electron microscopy is normal at onset but increases after 2 to 5 years of diabetes. Typical changes of diabetes on electron microscopy include GBM thickening and mesangial expansion.

In studies of renal function and structure in long term diabetes, we have found that GBM width does not correlate with blood pressure or GFR and has only a very weak relationship with urinary albumin excretion (UAE). Thus, GBM widening appears to be a relatively generalized phenomena in diabetes but does not correlate with clinical nephropathy. On the other hand, fractional mesangial volume (VvM) correlates well with GFR, blood pressure and UAE. Peripheral capillary filtration surface per glomerulns (SLE) has a striking relationship with GFR and also correlates with blood pressure and UAE. There is an inverse relationship between VvM and SLE indicating that progressive mesangial expansion is at the expence of the peripheral capillary filtration surface. In very recent studies, the fractional volume of the interstitinm of the kidney cortex correlates with GFR and UAE and appears to be additive to VvM in step-wise regression; exact mechanisms whereby interstitial volume influences GFR are yet to be determined.

We have evaluated the relationships between renal structure and microalbuminuria more closely and found that glomerular structure varied from normal to abnormal in patients with normal UAE, GFR and blood pressure, and in patients with microalbuminuria and normal GFR and blood pressure but was consistantly abnormal in patients with microalbuminuria and hypertension, decreased GFR or both. Thus, microalbuminuria when present with hypertension, a decreased GFR or both is a powerful predictor of diabetic nephropathy. However, normal albumin excretion or microalbuminuria without other functional abnormalities does not appear to accurately predict the severity of the underlying glomerular lesions in longstanding diabetes.

We have recently evaluated renal structure and function in early diabetes. In 50% of these studied patients with diabetes for only 5 to 12 years, we have found striking arteriolar lesions on light microscopy consisting of hyalin deposition within the arteriole and intimal fibrous thickening. GBM is thickened in over two-thirds of the patients and expansion of the mesangium is noted in 32%. In this early phase of diabetes, renal structure did not correlate with UAE, GFR, blood pressure, renal plasma flow, or glycosylated hemoglobin. However, as in long-standing diabetes, patients with normal UAE had renal structure that varied from normal to abnormal as did patients with microalbuminuria.

Thus, renal biopsy lesions can be seen in at least 1/3 of patients who have only 5 to 12 years of diabetes and no overt clinical signs of nephropathy. Renal function parameters do not appear to indicate the degree of renal structural change present on renal biopsy in early diabetes. Individual D patients may vary markedly in the clinical expression of the developing lesions of diabetic nephropathy (DN).To evaluate this we examined the relationships among BP, glomerular filtration rate (GFR) and G structure in 64 D patients without overt DN, divided into 3 groups according to albumin excretion rate (AER): normal AER (<22 mg/d) (N); low level miero~albuminuria (22-45 mg/d) (LM), and microalbuminuria (46-220 mg/d) (M). 32 N patients were normo-tensive (Nt) (MBP 84.4_+6.4 mm Hg, GFR 113+23 ml/min/ 1.73m 2) and 6 hypertensive (>140/84 or on antihypertensive therapy, GFR 109-+30) (Ht). 122 age and sex matched non-D kidney donors served as controls (C). In C glomerular basement membrane (GBM) width was 354_+53 nm, mesangial fractional volume (Vv M) .14_+.04 and surface density (Sv(PGBM)) .128_+.022 gm2/gm 8. In NNt GBM width was 512_+126 (p<0.001 vs C), Vv M .22_+.07 (p<0.001 vs C) and Sv (PGBM) .103_+.025 (P<0.001 vs C). No differences were observed in NHt vs NNt. 10 LM (AER 31_+6) patients were Nt (MBP 86_+6, GFR 124_+33, ns vs N) and only one was Ht. GBM width was 576+105, Vv M .21_+.06, Sv(PGBM) .108_+.028 (ns vs NNt). 7 M patients (AER 100_+47, GFR 110_+36) were hit, but their MBP (92_+5) was greater than NNt (p<0.005) and LM (p<0.05), 8 were Ht (AER 110_+40, GFR 97_+13). In MNt and MHt, respectively, GBM width was 581_+178 (ns vs NNt) and 713_+61 (p<0.001 vs NNt), Vv M was .26-+.07 (ns vs NNt) and .29_+.07 (p<0.05 vs NNt) and Sv(PGBM) was .075_+.018 (p<0.01 vs NNt) and .074_+.01 (p<0.005 vs NNt). GBM and VvM were significantly greater only in MHt vs NNt, while Sv(PGBM) was reduced in both M groups. In conclusion: 1) In all the D groups, including N patients, D glomerular lesions are detectable. 2) Patients with LM do not differ from N patients in G structure and BP levels. 3) M patients have higher GBM width and Vv M compared to N only when high BP is present. 4) MNt have significantly higher BP levels and lower Sv(PGBM) than N before a clear difference in other glomerular structures is evident. These data suggest that in D glomeruli may respond differently to similar degrees of mesangial expansion, and that it is those patients who have an early reduction in Sv(PGBM) who manifest M and rising BP.

S-19.4

Induction of experimental diabetes causes a rapid increase in renal and glomerular size accompanied by increases in kidney RNA and protein, demonstrable 36 h after the onset of glucosuria. Increased renal growth and function are preceded by a rise in renal tissue concentration of insulin-like growth factor I (IGF-I) reaching a peak 24-48 h after the induction of diabetes and returning to basal levels after about 4 days. Diabetic kidney hypertrophy is linearly dependent ~ on blood glucose levels one week after induction of diabetes and the degree of kidney IGF-I accumulation 48 h after injection with streptozotocin is directly proportional to the prevailing blood glucose in rats with graded severities of diabetes. In addition, IGF-I infusion to diabetic rats commencing after the initial high growth rate has abated, with restoration of the initial high kidney IGF-I levels, reaccelerates diabetic renal hypertrophy. Concomitant with the rise in endogenous kidney IGF-I, a transient increase in kidney IGF binding proteins (IGFBPs) is seen, supporting the notion that IGFBPs may modulate the renotropic action of IGF-I in diabetic renal enlargement. Diabetic dwarf rats with isolated growth hormone (GH) and IGF-I deficiency exhibit slower and lesser initial renal and glomerular hypertrophy as well as a smaller rise in kidney IGF-I than diabetic controls with intact pituitary, indicating that GH per se may be involved in the modulation of renal enlargement. Strict insulin treatment abolishes both the increase in kidney IGF-I and renal hypertrophy. A long-acting somatostatin analog (octreotide) equally inhibits kidney IGF-I accumulation and growth without affecting the blood glucose levels. These results indicate that IGF-I acts as an initiating growth factor for diabetic renal hypertrophy in experimental diabetes. At present there is no direct evidence that IGF-I is involved also in maintaining diabetic kidney hypertrophy and function.

However, in view of the evidence that octreotide may directly inhibit IGF-I synthesis independently of GH inhibition, it is intriguing that six months administration of octreotide to diabetic rats reduces diabetic urinary albumin excretion, renal and glomerular hypertrophy and serum serum kidney IGF-I levels without affecting metabolic control. Furthermore, reduction in renal size and hyperfunction is seen in Type 1 diabetic patients treated with octreotide for a period of three months without discernible reductions in serum GH, glucagon or HbAlc, but with pronounced reductions in circulating IGF-I levels.

In conclusion, the cited studies suggest that IGF-I is a factor that should be recognized among the many proposed biochemical and hormonal candidates in the development of early diabetic nephropathy and that inhibition of its participation may be rewarded. In recent years we have seen the emergence of molecular biology as a tool for studying vasoactive hormone systems and complex diseases such as hypertension. The cloning of cDNA and genomic clones of genes relevant to cardiovascular regulation and their use as molecular probes has allowed investigators to examine the expression of these genes in vivo under normal and pathophysiologieal states. With recent advances in gene transfer technology and genetics these cloned gen~ become important tools with which we can probe the cardiovascular system. The renin-angiotensin system (HAS) is probably one of the most studied regulatory systems involved in arterial pressure and electrolyte balance. I will use this system as a model to demonstrate how recent advances in transgenic animals and molecular genetics have impacted hypertension research.

The cloning of renin cDNA and genomlc clones from a variety of species has been a useful tool for studying renin expression in vivo; and its tlssue-specificity has been extensively examined in the rat and mouse. Apart from a descriptive analysis of the pattern of renin expression the molecular mechanisms regulating the renin gene were unknown. In an attempt to develop model systems for this analysis investigators developed transgenic mouse models containing the renin gene. These initial studies, using genomic clones of mouse renin, demonstrated the utility of the approach by accurately reproducing tissue and cell-specific expression of the injected renin con~ructs (1, 2) . A second generation of constructs cumainin~ only the renin promoter region and a reporter gene allowed investigators for the first time to dissect the promoter region and identify sequences essential for tissno-specific renin expression (3). The choice of a potent oneogene as the reporter also allowed the isolation of a banafide renln expressing cell line now being used for a more thorough molecular analysis of the renin regulatory region (4) .

Recently, transgenic mice have been used as a tool to examine the expression and regulation of the human renln genc. Although human renin clones have been available for some time their use was limited due to the scarcity of fresh human tissues for molecular analysis. We recently reported the characterization of transgenic mice containing a human renin genomic clone encompassing the entire gene and extending approximately 900 base pairs upstream and 400 base pairs dewnstream of the gene (5). Expression of the human renin transgene was evident in kidney, adrenal gland, ovary, testes, lung and adipose tissue but not in liver, heart, salivary gland or brain. Expression of human and moose renin genes in kidney were equivalent; and expression of human renin mRNA was increased 3-fold after S-days of oral captopril. An equal amount of active human and mouse realns were also released into the systemic circulation.

Transgenlc animals have also been used to examine the RAS in hypertension. Transgenic mice containing both the rat renin and angioteasinngen genes, or the rat angiotensinogen gene alone exhibit a sustained increase in arterial pressure reversible by treatment with angiotensin converting enzyme inhibitors (6, 7) . Transgenic rats containing the mouse Run-2 gene exhibit severe hypertension despite having low PRA and attenuated renal renin expression (8) . Expression of the transgene is elevated in several extra-renal tissues suggesting that extra-rennl RAS may play a role in the pathogenesis of hypertension in this model.

The implication that the RAS plays a role in the development of hypertension prompted investigators to determine if there is a genetic linkage between the renin geno and a predisposition to hypertension. This approach, often teemed the candidate gene approach, sought to determine if specific alleles of the renin gene cosegregated with hypertension in F2 cro~,ses of genetically hypertensive and normotensive rat strains. Although a linkage between a restriction fragment length palymorphism was found between SHR and Lewis rats, and between Dahl RR/Jr and Dahl SR/Jr rats, no such linkage was found between SHRSP and WKY rats (9-11).

One complication of the candidate gene approach was the limitation placed on the investigator hy the specific gene in question. Another approach teemed the reverse genetic or anonymous marker approach was utilized because one didn't need to make any assumptions as to which genes were important. All genes could be simultaneously evaluated if one bad access to genetic markers evenly distributed on each and throughout each chromosome of a hypertensive and noemotensive strain. These markers could be mapped in F2 cohorts of these strains. The presence of a specific marker cosegregating with higher blood pressure could be indicative of a possible linkage between a genc located near the marker and high arter~ pressure. Such an analysis on sodium-loaded animals from an F2 cohort derived from SHRSP and WKY revealed linkage of a gene teemed Bpl (blood pre&sure 1) to a marker (RDI7, growth hormone) on chromosome 10 (12,13). An analysis of genes in this region by synteny analysis, somatic cell hybrids and finally by genetic mapping in the SHRSP X WKY intercross revealed the presence of the angiotensin converting enzyme gene. The ACE gene is a candidate for Bpl. The effects and handling of drugs in the kidney of the newborn are complicated and difficult to study in the developing organism. In recent years, as more low birth weight infants have survived the immediate postpartum period, the relationship between drugs and the immature kidney have become more important.

Many more infants are not only receiving drugs such as diuretics, which act directly on the kidney, but are being treated with drugs that effect cardiac and pulmonary function such as theophylline and dopamine.

In this symposium we will present four papers reviewing several different aspects of renal pharmacology during development.

Hypoxic injury, as well as drug induced injury, are frequent, serious complication of cardiopulmonary diseases and their treatment in the premature infant.

In her talk entitled "The ameliorating effects of calcium blockers on renal function after hypoxic injury", Dr. Eunice John will discuss studies on the effects of calcium channel blockers in modifying the renal injury to hypoxia.

She and her colleagues at the University of Illinois have been carrying out studies in animals to determine if this class of drugs will improve the outcome.

Norman Siegel and co-workers at Yale University have also been investigating renal injury.

Dr. Siegel will discuss "Accelerating re-covery from drug induced renal toxicity". These investigators have applied a variety of methods to analyze energy utilization by the injured kidney.

They propose to vary the course of recovery by modifying cellular energy depletion.

The ability to understand the interaction of drugs and renal function will be the emphasis of the paper entitled "Novel methods to evaluate kidney-drug interactions" presented by Dr. Gideon Koren of the Hospital for Sick Children in Toronto.

Finally, Dr. Michael Bailie of the University of Illinois College of Medicine at Peoria will review "Diuretic pharmacology in the newborn kidney".

He will emphasize the limitations of knowledge on the pharmacology of diuretics in the developing kidney and the results of studies of the use of diuretics in some diseases of the premature infant.

S-21.1

EFFECT ON RENAL FUNCTIONS AND CEREBRAL AND RENAL HEMODYNAMICS. *E. John, T. Raju, L. Fornell, R. Shankararao, University of Illinois at Chicago, Chicago, U.S.A., 60612.

Although Ca ++ channel blockers are used for brain for HI insult, their effects on renal functions (RF) when given after HI are unknown in developing kidney.

In 8 piglets (7-9 d) we studied renal function (RF) changes due to NIM given after HI insult, which was 3 min of 8% 02 breathing followed by 2 min of carotid occlusion. After 15 min of insult, NIM was given as 5 pg/kg IV bolus and 0.I ~g/kg/min infusion for 2 h i controls received equal volumes of placebo (PL). Mean blood pressure (MBP mmHg), GFR (ml/min/gkw), PAH clearance (Cp^n, ml/min/gkw), osmolar clearance (Cos M ml/min), renal blood flow (RBF by microsphere ml/gkw/min) were measured at 15-30 min intervals.

Cardiac output by Transonic Doppler, and cerebral blood flow (CBF) (microspheres) were also measured.

HI insult reduced MAP, GFR, CpAH, and FENa. NIM bolus further reduced MBP by 38%-53% of baseline. RBF did not change significantly between groups or between time periods during the experiment. Renal functions were more significantly affected in the PL group than in NIM group (Table: x values for baseline and 60-90 min recovery. *=P<0.05 recovery vs baseline).

HI insult increased CBF and RBF by 42-118% the baseline; however CBF progressively declined irrespective of therapy.

During recovery, drops in CBF was more severe in NIM than in placebo group.* Table 1 Studies of membrane vesicles allow identification of specific transport characteristics, but lacks the cellular and organ apparatus.

The monolayer of tubular cells grown on filters allow direct view of site of interactions and mechanism of transport. Using the above techniques we have recently characterized the specific transport of digoxin across the renal tubular cell, and the nature of common drug interactions with the glycoside.

Supported by MRC grant 8544. Over the past many years, it has been well known that a number of manipulations which will lessen the severity of a renal insult can be carried out prior to the administration of a nephrotoxic drug. In general, these pertubations have included: a solute diure~is produced by intravascular volume expansion, the administration of m~nnitol or furosemide. ~nese manipulations have been successful in preventing or lessening the degree of injury related to contrast agents, antibiotics and che~gtherapeutic drugs.

In 1971 it was first suggested that thyroxin (T4) might have a protective effect in the amelioration of toxin induced acute renal failure. Subsequently, it has been shown that administration of this hormone significantly accelerates recovery from a number of different types of acute renal injury including HgCI2, dichromate, uranyl nitrate, gentamicin and ischemia. Cronin and associates demonstrated that the administration of T 4 for i0 days before and for sevel-al days after exposure to gentamicin or uranyl nitrate resulted in a significant i~provement in overall renal function, urine osmolality and enzyme activity. Utilizing the dichromate irK~ced model, studies frc~ our laboratory and by Michael, et al have shown that the administration of a single dose of T 4 at the peak of the renal insult would provide a st~us for the accelerated recovery of renal function and for the induction of cellular proliferation.

Additional studies have been designed to determine the potential for clinical application of these observations and to more clearly define the cellular mechanisms responsible for this beneficial effect. Studies carried out in our laboratory have demonstrated that T 4 is effective when administration is delayed for sevel-al hours or days after the initial insult and that treatment results in accelerated recovery which is sustained so that treated animals reach normal levels of renal function well in advance of controls. Humes and co-workers have made a particularly i~oortant observation that T 3 enhances renal tubular cell replication by stimulating epidermal growth factor (EGF) receptor gene expression. These studies would build on the known effects of thyroid hormone on a variety of growth factors and suggest that the ability to increase EGF receptor gene expression would potentiate the mitoqenic response to EGF and thereby accelerate the recovery of renal function. Studies from our laboratory have demonstrated that beneficial effect of T 4 is not related to a stabilization of the plasma membrane, and that the stimulation of recovery of cellular ATP which is associated with administration of the ho~none is related to an effect directly upon mitochondrial processes involved in post-injury ATP synthesis. Finally, recent studies from our laboratory have shown that the administration of thyroxin following an ischemic renal insult can protect the injured kidney from the additional toxicity conm~nly associated with the administration of Cyclosporin-A. These observations may have significant clinical implications. S-21.4 Diuretic Pharmacology in the Newborn Kidney. Michael D. Bailie, Department of Pediatrics, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61656, USA.

With the increased survival of the low birth weight and the sick full-term newborn infant, the use of diuretics has increased in-the neonatal intensive care nursery. Diuretic drugs are now one of the most commonly used drugs in this setting.

They are being utilized for treatment of many problems in the newborn including respiratory distress syndrome, bronchopulmonary dysplasia, hyper-tension, congenital heart disease, heart failure, fluid overload and edema.

In addition to the fact that the kidneys of many of these infants are not fully developed and that those nephrons that are developed are functionally immature, the various diseases of the premature newborn will also have potential impact on the effect of diuretic drugs.

The major diuretics act from the tubular lumen. Many of these drugs are not only filtered but also are organic acids, and, are secreted into the tubular fluid. Furthermore, protein binding may limit the filtration route.

Studies on the pharmaco-kinetics and pharmacodynamics of diuretics in the premature infant are difficult. Such studies may require frequent blood sampling or accurate col-lection of timed urine samples. Furthermore, since many of these infants are sick and receiving drugs that may affect diuretic action such as other organic acids, the determination of the appropriate parameters is difficult at best.

It has been suggested that methods used in adults are not as useful in the newborn to study diuretic pharmacology.

Recently, Green (Dev Pharmacol Ther 11:357, 1988) has suggested an approach which while still requiring urine collection ~!4mi~at~ the need for freq~ent blood sampling and may allow easier evaluation of diuretic pharmacology in small and sick infants.

Fursemide is the best studied diuretic in the premature infant. Thiazide diuretics have been used in the premature infant to reduce hypercalciuria and possibly moderate nephro-calcinosis secondary to treatment with furosenide.

However, there are limited studies on several other diuretics in premature and older children.

A recent literature search found no studies of cellular mechanisms of diuretic action on the immature renal tubule.

S-22.0

Evelyn Reichwald-Klugger I, Ch. Holmberg ~ University Children's Hospitals Heidelberg I and Helsinki ~ The confrontation of a child or adolescent with the diagnosis of CRF implies many physical and emotional burdens which in most patients call for external support by their families. During the course of the disease the patients and their families are primarily confronted with the following emotional problems: mental shock by the recognition of the irreversible life-threatening state of CRF requiring a high degree of resistance against painful and unpleasant procedures, compliance with medical instructions and dependence on drugs, technical equipment and hospital staff. The disease is frequently accompanied by injuries to the patient's body (scars, growth retardation, delay of puberty etc.) which makes it visible to everyone. Social integration becomes a difficult task for a child with CRF. The relationship with parents and siblings is frequently neglected. The educational and vocational training is usually impaired, especially in patients with long-term dialysis treatment; even transplanted patients encounter problems in finding a suitable job. In addition, many families suffer from financial restraints induced by the disease. The individual psychosocial problems of CRF patients place extremely high demands on doctors and nurses. As a consequence professional psychosocial care for these patients has been integrated successfully in many pediatric dialysis and transplantation centers during the last decade. The structure of these services has to take into consideration the local and regional conditions. The wide spectrum of tasks that the members of a psychosocial team must fulfill requires a long specialized training closely integrated into the clinical institutions. One important aspect is the wide range of age, social level and severity of CRF to be covered by the psychosocial renal centers. The increasing number of infants and toddlers accepted for treatment of end-stage renal disease requires a thorough and regular assessment of psychomotor and cognitive development.

In style of information to have been insufficient but also reported a higher incidence of own psychosomatic symptoms and/or behavioral disturbances in family members following diagnosis. Quality and extent of preparatory information regarding RRT correlated with the families" readiness to accept the respective modes of treatment. About 75% of the families felt that the professionals should have informed more actively, and consequentely did not feel sufficiently informed prior to dialysis, but significantly less so prior to transplantation.

Having to "run after the doctors" for more and digestable information added to the feeling of dependency and insecurity. In contrast, better information increased trust in the health care providers and reduced the families' feeling of being at the disposal of others. The patients' cooperation or non-compliance, respectively~ was related to the different aspects of the multidimensional model of illness related behavior formation mentioned above: there was a tendency to non-compliance as well as to higher incidences of rejection in those patients with doubts as to the appropriateness of the applied modes of RRT. But there was less non-compliance in those patients, who felt actively informed and treated age-appropriately.

They also reported, that their sense of autonomy had been taken care of, that they had been allowed to take influence on certain details of the treatment, and that their efforts to cope had been actively appreciated by their health care providers.

Several patients and their families related incidences of non-compliance to the fact that they experienced the medical regime as being socially intrusive into their personal life-style. They conveyed reluctance to talk openly about non-compliance with their doctors for mainly two reasons:

(i) sympathetically, they experienced doctors to work under too high a work load and as being only partially able to understand the families' multiple pressures and (2) Chronic renal failure (CRF)is reported to have a negative influence on the cognitive and motor development of children, particularly when these children are very young. However recent studies present a more optimistic perspective by their findings of developmental progress due to medication, treatment modality or early transplantation (1, 2) . An important question is whether an earlier start of renal replacgment therapy may prevent or ameliorate the reported developmental retardation.

To answer this question a prospective 3-year study into the effects of CRF and dialysis treatment on the motor and cognitive development of young children was performed. Children were recruited from 3 Dutch dialysis centres. Inclusion criteria were defined by age (< 5 years) and creatinine clearance (< 25 ml/min/1,73 m2). These criteria were fullfilled by 31 patients (0.4 -5.0 years), in three treatment groups: patients in socalled conservative treatment (n=11), patients in dialysis treatment (n=13) and patients who switched from conservative treatment to dialysis treatment during the course of the project (n=7). The motor development, examined in one dialysis centre on 24 patients, was assessed by the Hoskins and Squires test. The cognitive development was tested in all 31 patients using the Bayley Developmental Scales for children under 2,5 years and the McCarthy Developmental Scales for the older children. Tests were performed every 3 months in infants and every 6 months in children > 1 year of age.

The motor development of the total group was seriously delayed, the mean motor quotient (motor age divided by chronological age) was 0.68. Patients on conservative treatment (n=9) scored significantly better than dialysis patients (n=8). Splitting up the total score in scores on gross and fine motor functioning revealed that these group differences were only due to gross motor performance.

The cognitive development of the total group was significantly (p<0.001) delayed in comparison-with a normal population. The mean Developmental Index (DI), calculated by averaging the successive measurements per patients, was 80 (SD=18), while the mean of the normal population is 100 (SD=16). Conservatively treated patients (n=11) scored lower than normal (91.5), but significantly higher than the dialysis patients (67.1, n=13). A number of these dialysis patients had multiple congenital diseases. These children (n=7) had a much lower mean Developmental Index (56.1) than the other dialysis patients (79.9, n=6). The effects of starting dialysis treatment on cognitive functioning, investigated in the third group of patients, appeared to be positive, but a significant improvement (from 77.9 to 90.0) was only observed within the first 2-6 months of treatment, and 8-16 months later this improvement (to 85.2) was no! significant any more.

The present study revealed that preschool dialysis patients, more than the patient s in conservative treatment are at risk in their motor and cognitive development. Additional research showed that the difference between these two groups could not be explained by a number of medical and psychosocial factors although evidence was found for a relation with residual renal function and with multiple congenital diseases. Parental stress due to dialysis treatment must also be considered. No evidence was found for the hypothesis that starting earlier with dialysis treatment will lead to better developmental chances. Only a temporary improvement could be demonstrated. However, more research is necessary to monitor a greater number of patients longitudinally. 

History is full of the exploits of short people, fighting their way upwards against the odds; fairy-tale dwarfs are either "cuddly toys" or the epitome of evil. In a society that over-values physical prowess, the "little man" may be looked down upon in all senses of the word.

Many psyehosoeial studies hax, e been flawed in their methodology, lumping together all causes of short stature with a a heavy assumption that it must lead to emotional problems -by no means proven in conflicting results. Growth hormone treatment has added to the confusion by being used not only for hormone-deficient children, but those constitutionally short children at the bottom end of the normal height range and those with chroule disease in which short stature may be part of a global unhappiness.

WI~e many children will undoubtedly benefit, we must be careful not to offer a long-term, invasive and expensive "panacea" for over-protectlve parents instead of tackling social expectations or the general psychology of illness. As we cannot always predict which children will respond to hormone therapy, we may leave some even more frustrated by offering a treatment that does not deliver results. Most patients with an onset of CRF in childhood at some point outgrow the competence of pediatric care. This raises the following questions: i) What is the optimal age for a transfer to an adult unit? 2) Which are the clinical and psychological criteria to support the decision-making? 3) What is the psychosocial outcome of patients after discharge from the pediatric unit? Recent policies for the transfer of pediatric patients to adult units differ widely, e.g. in the eastern part of Germany patients were regularly transferred before the age of 18 years. In contrast, a recent study on 518 paediatric patients observed in western Germany revealed that nearly one-third were older than 18. An assessment of the late medical and psychological findings of patients who have left their pediatric unit might help in defining criteria for an optimal time of transfer. Preliminary results from a survey of 27 pediatric CRF patients who were discharged from our unit and entered an adult renal unit during the last 4 years are presented. Both clinical and psychosocial data were asked for by a questionnaire. 50 % of patients had been discharged more than 2 years ago. At the time of assessment the patients had a mean age of 22.5 (range 18-28 years); 15 of them had a functioning graft, 8 were on regular hemodialysis treatment and 4 were in preterminal CRF. All patients except 2 had graduated, 13 were taking vocational training, 9 working full-time, and 3 were without occupation. One-third of the patients received no financial support. 5 were married and one male had a child. Except for 2 all patients lived with their parents. Only 9 reported to practice sports regularly. Professional psychosocial support was not available in 75 % of the adult units where the patients were followed further, although half of them expressed their wish for such support being available. The findings will be compared with patients aged >18 years who remained under pediatric care. We conclude that the age for transfer of an adolescent with CRF from a pediatric to an adult renal unit must be chosen individually, taking into account medical as well as psychological findings. The psychosocial team of a pediatric unit seems to be in an optimal position to support a smooth and gradual detachment of the CRF patient, thus enabling him to reach autonomy and integration into adult and professional life.

S-23.1

The South-North gap in key human survival indicators have narrowed considerably in the last three decades. Developing countries (DC) populations are much healthier and more educated than before. Infants and child mortality were reduced by more than 50% between 1960 and 1990, an achievement that took more than a century in developed countries. However, in the same period the disparity in technological education, research and development indicators, have dramatically widened. For instance, scientific and technical personnel in the South, number only 9 per 10130 people, compared with 81 in the North. The disparity of income between the world's richest billion and the poorest billion is mote than 150 to one (1) .

Chronic illnesses have increased in relative and absolute terms as a result of the decrease of acute diseases due to effective prevention and cutting-edge diagnosis and therapy technology such as programs of oral rehydration therapy for acute diarrhea, immunization and improvement of pregnancy and birth care. The increasing prevalence of acute and chronic renal diseases is an outstanding feature of the epidemiologic transition. Therefore, poor countries are facing the chaUeage of caring for a growing population of children with "new" diseases.

A new approach to organization of services is needed in DC. Feasibility assessment of pediatric services should not be based exclusively on the availability of financial resources. As the 1990 report of the United Nations Development Program (UNDP) which emphasizes: "the lack of human development is more related to to the degree of political engagement than to the availability of financial resources" (1).

Efficient development of PN services requires a comprehensive training strategy covering cognitive skills and managerial aspects. Pragmented and inadequate training focuses exclusively on medical aspects without taking into account the specific local eharacteristies of DC's is a major source of inefficiencies; wrong incorporation of medical equipment, overuse of costly procedures, unnecessary transfer of patients to foreign developed countries, and migration of skilled professionals to rich countries.

Three examples of waste of resources: a) The cost of 10 gm of ceftriaxone for the treatment of a child with a "wrong" diagnosis of urinary tract infection in Uruguay is more than 30% of the monthly salary of a nurse-aid, b) in Ghana, 60% of doctors trained in the early 80's are now living abroad, leaving a critical shortage of health services, c) a Latin American study revealed that 96% of all the equipment impm'ted between 1975 and 1979 was not functioning in 1981. Needs are tremendous and resources extremely limited. There is no margin for any waste of time, money and energy. Adequate organization of PN services based on comprehensive training including managerial aspects, priority on human capital investment, rational incorporation of hardware, optimization of available resources, developing low cost technology, cooperation between North-South and South-West, with a similar epidemiology and demography, PN twinned units, effective prevention of renal diseases such as proper care of children with obstructive uropathy, pyelonephfitis and neurogeuic bladder. Therapeutic regimens, especiatly in developing countries, must be cost-effective and simpte; those with unproven or ambiguous efficacy should be avoided despite the temptation or a demand "to do something".

Long distances to special centers and comptiance with treatment are important factors that influence adequate management. Special emphasis needs to be placed on education of the family and prompt treatment of complications to avoid repeated hospitat admissions.

Nephrotic syndrome.

Most patients with minimat change nep~rotic syndrome can be managed with judicious use of prednisone.

As far as possible, the treatment should be carried out by the local physician, who may foltow clear guidelines given by the pediatric nephrologist.

For patients with frequent retapses or steroid dependence, tongterm, tow-dose prednisone and levamisote may be employed before considering cytotoxic drugs or cyclosporine.

Early treatment of edema is crucial since peritonitis and other serious infections, the chief causes of mortatity, are particutarly common in patients with anasarca. Head-out water immersion (HOWl), rarely a therapeutic option in rich countries, shoutd be used before infusions of albumin,

We have found HOWl to be particularly beneficial in patients with massive ascites, resistant to large doses of diuretics.

Long-term therapy with anticoagulants and antiplatetet agents is rarely indicated in patients with persistent forms of gtomerutonephritis.

Urinary tract infections. A majority of patients with uncomplicated acute UTI can be treated with wetl-established drugs (co-trimoxazote, nitrofurantoin) given for i0 days. Compliance with treatment should be ensured.

There is a need to evaluate shorter treatment schedules. Standard recommendations regarding imaging studies should be fotlowed.

With widespread avaitability of uttrasonography, renal and urinary tract anomaties are being frequently detected. Definitive surgical procedures (e.g. nephrectomy for unilateral multicystic dysplasia, ureteric reimptantation for vesicoureteric reflux) shoutd have a preference over conservative management and palliative procedures that require tong-term care or prophylactic chemotherapy. Acute renal failure.

In a majority of cases ARF results from preventabte conditions,

The need for educative measures and prompt and vigorous treatment of such disorders is obvious. Peritoneal dialysis is adequate in most cases.

A treatable cause should be sought and appropriate surgical treatment carried out. For tong-term treatment of chronic hypertension, a greater reliance should be ptaced on dietary sodium restriction and chtorothiazide, which @tong with drugs such as hydratazine and beta blockers may usually suffice. 

Umvers~ Chil~en's Hospk~, Stem~esstr~se ~, CH-~32 Zurich,

Paediatric nephrology is in a serious dilemma when faced with the demand for modern technology in countries which have many unsolved basic problems. It is not always realized that application of newer technology is much more than just a matter of Finances: Besides careful fraining, a different approach to the work itself in terms of efficiency and quality is needed. Strong mobivstion is essential. Where should priorities be given? This mainly depends on the local situation and the historical background. The problems in the former Sovietunion and in some eastern European countries differ inherently from those in the southern hemisphere. Our own experience in Armenia, where a longterm medical programme emerged From acute help affer the earthquake of 7.12.88, has shown to us that in a particular situation_ it is possible to start with a sophisticated method (haemodialysis) before building up a solid infrastructure with basic nephrology and urology. Practical considerations: Since any technology is appropriate only as long as it can be integrated into a given system, the goals that can realistically be reached have first to be defined. The requirements to be met concerning time, funding, material, persons involved, responsibilities and training facilities are then defermined. A partnership (twinning) with another centre is an efficient way and can be very rewarding for either side. Prerequisites for twinning to become successf'ul are: Personal involvement, mutual respees mastering a common language, continuing support and acceptance of given limitations. What is appropriate technology? Basic principles are: Equipment must not necessarily be new, but should be sturdy and amenable to local servicing. Not the initial costs, but the subsequent longterm costs (e.g. for reagents) are critical. All anterior pituitary hormones are secreted in a pulsatile fashion. Both frequency and amplitude are important for the biological stimulus to the gonad. The pituitary gland acts as a modulator, increasing the amplitude of the signal, while the hypothalamus controls the pulse frequency. (InRH is the only hypothalamic-releasing hormone which controls the differential release of two pituitary gonadotrophins, LH and FSH. The exact mech~lim whereby this occurs has not yet been fully described, although changes in pulse frequency, within the physiological range, are not as important as had previously been believed and may predominantly reflect sex steroid concentrations.

Conadotrephin secretion is not quiescent during childhood. Low amplitude, high f~equeficy bursts of gonadotrophin secretion probably occur during early childhood which are relatively inf~eduant and not linked to the night time. When pulsatile CnP~q secretion has become entrained to the night, and every night, this is synonymous with the appearance of a milticystic ovarian morphology (> six cysts of > 4m~ in diametre). Sex steroid'levels continue to rise, related to the increased amplitude of nocturnal gonadotrophin pulses, a threshold is attained which induces secondary sexual characteristics. This is the onset of phanotypic puberty but the endocrine changes have continued throughout childhood. The establishment of high amplitude gonadotrophin poises during the daytime, as well as at night, is a prerequisite for the LH surge and the development of ovulatory menstrual cycles. In delayed pubertal development, the devotee of gonadotrophin insufficiency produces a clinical spectrtm between complete absence of secondary sexual characteristics and failure to attain ovulatory cycles.

There is an important interaction between OH and gonadal maturation. OH augments the action of gonadotrophins on the gonad. In beth rhesus monkeys and hamans with isolated OH deficiency, GH treatment is associated with acceleration of the rate of pubertal maturation. It may be that the effect is dese-dependent and ~my well limit the pharmacological use of CH treatment in conditions wbJ_ch b~ve endogenous puberty. The induced increase in ~owth rate with GH treatment may be coenteracted by an increased rate of epiphyseal closure. The increased GH secretion in pubertal children with chronic reeal failure is probably related to end-organ hyporesponsivesees. However, whether this hyporesponsiveness effects the gonad as well as cartilaginous Erowth plates is unknown. Delayed sexual maturation and impaired pubertal growth are major complications of advanced chronic renal failure (CRF). Reports from the EDTA Registry suggest that pubertal development in end-stage CRF starts with an average delay of about two years. In a recent retrospective longitudinal analysis of pubertal growth in CRF, we found a similar delay of the pubertal growth spurt (Pediatr Res 28:5-10). The age at onset of the growth spurt is inversely correlated with the duration of CRF. Whilst the duration of pubertal maturation does not appear to be prolonged, we observed subnormal testicular growth in boys with end-stage CRF, and late menarche followed by persistent menstrual cycle abnormalities are common in girls. The pubertal height gain is reduced to about 50 % of normal, resulting in an irreversible loss of growth potential and compromised final height.

To elucidate the endocrine mechanisms of delayed maturation and impaired growth during puberty, a prospective multicenter study has been initiated in 1987, which is still in progress. 70 patients (50 boys/20 girls) from 10 centers have been enrolled in this study; inclusion criteria were an age of > 10 years, Tanner puberty stage I or II, and a testicular volume of < 4 ml in boys. At entry, 25 patients were in preterminal CRF (GFR < 25 ml/min/1.73m2), 14 were on dialysis, and 31 after transplantation. Severe retardation of growth and development was documented at start of the study by a mean height SDS of -2 and a mean bone age delay of almost 2 years. Since pubertal development is associated with the emergence of a pulsatile secretory pattern of luteinizing hormone (LH), increasing LH bioactivity, and an amplification of episodic growth hormone (GH) secretion, studies of spontaneous LH and GH secretion are performed at annual intervals. Preliminary analyses demonstrate a reduction of LH peak frequency and fractional amplitude, and markedly reduced biopotency of the circulating LH in dialysed patients (Pediatr Nephrol 5:569-577). Differentiation of the LH profiles into the underlying secretory and eliminatory components by means of the deconvolution technique revealed that the production rate of LH is reduced by nearly two thirds in pubertal uremic patients. Since, probably due to impaired renal elimination, LH plasma half-life is prolonged, mean plasma levels are normal or even elevated. Whether this masked suppression of pulsatile LH secretion is of pathophysiological importance or rather reflects an adaptation to impaired metabolic clearance remains to be established. After transplantation, the observed changes appear to be reversible.

Pulsatile GH secretion appears to be altered primarily by modulation of peak amplitudes, whilst the frequency of GH peaks remains stable. The two major determinants of GH peak amplitude were pubertal progress (physiological increase to maximum at Puberty stage III/IV) and the degree of renal dysfunction (highest amplitudes in dialysed patients). In transplant patients, by contrast, the pubertal increase in GH peak amplitudes was diminished. We observed an inverse relationship between peak amplitude and corticosteroid dosage, suggesting suppression of GH release by these compounds. Since growth velocity was inversely correlated with GH peak amplitudes in transplant but not in uremic patients, it appears likely that pubertal growth failure is associated with GH resistance in the latter and with steroid-induced GH hyposecretion in the former. The further longitudinal follow-up of our patients should allow to correlate their endocrine abnormalities with clinical development. A)Ws studied the effects of chronic renal failure on the pituitar'y-cortisol axis and adrenal androgen function in 26 patients (16 male and l0 female), aged 6.5 to 22.5 years (mean 14.5). All of them were on Chronic hemodialysis. Pubic hair development was delayed in 56% of the patients. Serum cortisol was increased in 15 out of the 26 patients. Serum ,a 4-androstenedione was high in 11 out of 15 patients in Tanner's stage I or II and in 1 out of 11 patients in Tanner's stage III, IV or V ( p q0.01). Serum e ortisol was elevated in 10 out of 12 patients with high serum Ix 4-androstenedione and in only 5 out of 14 with normal A 4-androstenedione (p <0.02). Serum dehydroepiandrosterone sulphate was normal in 22 patients and elevated in 4 males. There was a significant inverse correlation between bone age and serum eortisol (r:-0.59: p<0.005) and a significant positive correlation between bone age and serum dehydoepiandrosterone sulphate (r:0.45 p <0.01). Serum ACTH was normal~ A reduction by 50% in cortisol and 78% in dehydroepiandrosterone sulphate was found after dexamethasone suppression, but /k 4-androstenedione did not suppress after dexamethasone. After ACTH stimulation test cortisol increased by 50% and /% 4-androstenedione by 80%. Following cortieotrophin-releasing hormone (CRH) stimulation 6 out of 10 patients (60%) showed an excessive ( ~ 810 nmol/1) rise in serum eortisol. Conclusions: The increased levels of eortisol and /k 4-an drostenedione with partial resistance to dexamethasone and excessive rise in cortisol after CRH suggest that these patients have a hypothalamie pituitary dysfunction similar to that found in Cushing's disease or in chronic stress. The difference in the responses of ~ 4-androstenedione and dehydroepiandrosterone sulphate observed is consistent with the existence of different mechanisms of control for these two steroids.

B)Growth retardation is frequent in end stage renal disease (ESRD) and after renal transplantation (Tx). Endocrine control of growth is influenced by a number of hormones, including growth hormone , thyroid hormone and sex steroids. In the present study we have attempted to compare thyroid function in ESRD and after Tx. The hypothalamie pituitarythyrotrophic axis was evaluated in 9 ESRD and 12 Tx patients, aged 7.5 -17.0 years (x: 12.0). In Tx patients, immunosuppressive treatment included cyclosporine, azathioprine and low dose steroid therapy (equivalent to 0.2 mg/kg/day of methylprednisone (MP)).

In ESRD mean total T3, mean total T4 and free T4 were significantly less than the normal mean (p <0.001).

In Tx patients, mean total T3 was normal, while mean total T4 and mean free T4 were significantly decreased. Mean peripheral thyroid hormone concentrations were lower in ESRD than in Tx patients (T3, p <0.05; T4, p <0.005; free T4, p~0.01) Basal TSH was normal. TSH increment to TRH was deficient (44.5 mUlL) in 3 ESRD and 8 Tx patients.While TSH response was prolonged in the remaining 5 ESRD patients studied, it was normal in the other 4 Tx patients. The circadian TSH secretion was studied in 8 ESRD and in l0 Tx patients, 5 of the latter were on MP therapy and the remaining 5 on deflazacort (D) (an oxazeline compound derived from prednisolone). The mean nocturnal TSH surge were 50 + 68 % , 47 + 95 % and 135 + 124% (x + SD) respect ively; 5 ESRD patients, 3 Tx natients on MP and 1 Txpatient on D-had nocturnal TSH surge below the normal range (95% confidence limits 47 to 300%). Our findings of low total T4 and free T4 levels associated with altered TSH response to TRH and an impaired nocturnal TSH surge, support the hypothesis that patients with ESRD and after Tx have central hypothyroidism. The presence of deficient TSH response to TRH in our Tx patients suggests that glucocorticoids which are known to decrease TSH secretion, may be acting predominantly at the pituitary level; perhaps partial recovery of the altered thyroid function can be achieved by lower doses of D. There is currently no definitive evidence to support or refute this hypothesis.

The similarities and differences between SHP and IgAN will be reviewed.

Although clinically distinct, similarities do exist.

If carefully examined, there is renal involvement in 100% of patients with SHP. Likewise, up to 30% of patients with IgAN develop poorly explained abdominal pain, atypical rash or arthralgia. SHP is more common in young children while IgAN presents in adolescents and young adults.

However, the true onset of IgAN is impossible to discern and may well precede clinical symptoms by years.

A systemic infection commonly precedes the oDset of SHP while it coincides with the clinical onset of IgAN.

Indeed, the onset of renal disease in SHP may follow the onset of systemic symptoms by weeks to months.

The renal symptoms in both SHP and IgAN may remit and relapse.

The nephritis of both SHP and IgAN may lead to ESRD. 20-30% of patients with IgAN and about 5% of all patients with SHP progress to ESRD. However, up to 30% of patients with SHP referred for renal disease progress.

There is a group of patients who present with SHP but soon remit all systemic symptoms and then follow a clinical course identical to that of IgAN.

Both IgAN and SHP recur in up to 50% of renal allografts but neither leads to graft dysfunction.

In sum, the clinical similarities are at least as striking as the differences in these two syndromes.

As noted, the renal pathology is the same in both conditions. Crescentic disease and subendothelial deposits are more common in SHP.

For this reason an increase in glomerular T-cells and activated mononuclear cells is more common in SHP but also occurs in IgAN with crescents.

In both disorders the mesangial IgA is sub-class one, I L chain predominates, and the same complement components are deposited.

"Normal" skin in SHP may show deposits of IgA while this is not true in IgAN.

The limited data on gut pathology in IgAN shows no evidence of perivascular immune deposits.

The incidence of diagnosed IgAN and SHP varies among continents.

It is of note that neither is seen in equitorial Africa.

Thus the two disorders have a very similar demography.

The pathogenesis of neither disorder is understood.

Patients with both have increased serum levels of IgA and IgA containing immune complexes and have IgAl rheumatoid factor and possibly autoantibodies to autologous collagen.

Likewise, both disorders have evidence of increased IgA immune response by B cells in vitro and in IgAN this has been confirmed in vivo.

In IgAN the clearance of IgA is normal and the clearance of IgA immune complexes is slightly delayed.

Similar studies have not been done in SHP.

Both disorders appear to have a genetic predisposition.

Their incidence is increased within certain families and siblings pairs with SHP and IgAN are reported.

We have observed one such sibship with HLA identical brothers.

Several MHC antigens have been variously implicated in IgAN, HLA DWw7 being the most recent.

No antigen has universally associated with disease.

Homozygous null genes at one or both C4 loci were associated with both IgAN and SHP.

However, this association occurred in a large extended family and was not confirmed in a multi-ethnic survey.

In summary, although clinically distinct, SHP and IgAN share striking similarities in all regards. It may be clinically useful to view these as a spectrum of one disease.

However, until the pathogenesis of each is better understood, they should be separated in any investigational study. (1) IgA nephropathy should be regarded as a syndrome. Schonlein Henoch purpura glomeru!onephritis (SHP-GN) and idiopathic IgA nephropathy (IgA-GN) represent the primary and the most frequent forms of this syndrome. SHP-GN and IgA-GN share the same histopathological features. Therefore, in spite of their difference in clinical presentation, a close relationship exists between these 2 diseases. In both, the glomerular involvement is characterized by a "mesangiopathy" with diffuse mesangial deposits that contain predominantly IgA and with varying degrees of hypercellularity and of superimposed crescent formation. For the sake of clinicopathologic correlations, 4 histopathologic categories may be individualized: characterized by the presence of a variable proportion of crescents superimposed on a proliferative endocapillary GN. We have subdivided this category in two grades, the cut-off point being 50% of crescentic glomerulL Several comprehensive clinicopathologic studies (2) (3) (4) (5) (6) have shown that in both diseases the best prognostic indicators are the severity of the presenting renal symptoms and particularly the amount of proteinuria as well as the histopathologic pattern. Overall, the larger the number of glomeruli affected by crescents, the poorer the prognosis. We have studied 151 consecutive children presenting with SHP-GN and followed for t to 18 years in order to determine the characteristics of the patients (pts) at risk of developing end stage renal failure (ESRF). Of the 91 pts with a nephretic syndrome (NS) at time of biopsy, 35 (38%) had a poor outcome defined by persisting signs of nephropathy and/or progression to ESRF. Fifty four of the 91 pts (59%) had shown on renal biopsy a EEGN with 50% or more of crescentic glomeruli. Pathology is a better discriminant prognostic feature than NS since, of the 68 pts with 50% or more of crescentic glomeruli 38 (55%) had a poor outcome, including 25 who progressed to ESRF. On long-term follow-up, Goldstein et al (7) have recently found that 17 pts deteriorated clinically from an initial assessment in 1971, 7 of whom had apparently recovered in 1976. We studied in parallel 157 consecutive children presenting with IgA-GN and tollowed for 1 to 16 years. Among the 119 pts with recurrent macroscopic hematuria, only 20 (17%) had a poor outcome, whereas of the 38 pts with microscopic hematuria, 21 (55%) had a poor outcome. By contrast, among the 25 pts with a NS 16, (64%) had a poor outcome. Twelve of these 25 pts (48%) had shown on renal biopsy a EEGN with 50% or more of crescentic glomeruli. Outcome was also closely related to histopathology~ w of the 21 pts with 50% or more of crescentic glomeruli, 12 (57%) had a poor outcome, including 8 who progressed to ESRF. Therefore, the 2 features which identify the severe forms of IgA nephropathies are the presence of a nephrotic syndrome and/or glomerular involvement characterized by 50% or more of crescentic glomeruli. However, in both diseases clinical recovery is possible and usually associated with histological improvement as demonstrated on repeat renal biopsies. A study of sequential specimens showed a disappearance of cellular proliferation and a decrease in the number and size of the crescents as well as a decrease or a disappearance of IgA deposits. The role of treatment in these improvements was difficult to assess since most patients with severe forms of IgA nephropathies had been treated. In the recent years we have undertaken a prospective study on the use of methlylprednisolone pulses in severe forms of IgA nephropathies. Our results indicate that this treatment is associated in a high proportion of cases with both a clinical and a histological improvement. Morever, the clinical tolerance of the treatment has always been excellent. 

Dept. of Pediatrics, CHU Sart-Tilman, B-4000 Liege, Belgium

As IgA nephropathy (Berger's disease) and Henoch-SchSnlein purpura ere probably two different clinical presentations resulting from similar pathogenetic mechanisms, inducing renal lesions only in the former illness and multisystemic lesions in the latter, we shall use the term "IgA nephropathies" (IgANs) to denominateboth diseases. High IgA plasma levels ere often found in IgANs. This increase concerns mainly the IgAl subclass.

An augmentation of the proportion of circulating polymeric IgA (IgAp) is reported by some authors.

The glycosylation pattern of IgA oligosaccharidic chains may be modified as sugKested by experiments studying the binding capacity of IgA to various lectins.

Specific circulating IgA emtibodies directed against exogenous (bacterial polysaccharides, ~ -galactosyl residues, alimentary glycoproteins, ...) or endogenous (I~A, IgG, DNA, albumin, endothelial cells, neutrophil cytoplasm, ...) antigens, havebeen detected. However most of those abnormalities do not correlate with clinical signs. On the contrary, elevated plasma levels of IgG auto-antibodies directed against several antigens (glomerular capillaries, mesangial cells, IgA and IgG Fab, idiotypes, ...) are found mostly during exacerbation phases of the diseases. Numerous studies have shown the presence of circulating IgAcontaining immune complexes (IgA-CIC) during macroscopic hematuria episodes, mainly when they contain IgG or/and IgAp. However, it must be stressed that high IgA-CIC plasma levels can also be found in other illnesses without any renal involvement (alcoholic liver cirrhosis, dermatitis herpetiformis, ...).

The hepatic clearance of macromolecular IgA is normal in IgANs. On the contrary, the Fc I-receptor (R), C3b-R and fibronectin-R function of the phagocytic mononuclear system are often reduced. However those abnormalities do not generally correlate with clinical signs, ere transient, and therefore, probably result from the hyperproduction of CIC. An in vitro and an in vivo hyperactivity of circulating and medullary B lymphocytes is observed in IgANs. This phenomenon leads mainly to an overproduction of IgAl not correlated with clinical signs. An increase synthesis of IgG and IgM is less frequently noted but is always associated with hematuric episodes.

Co-cultures experiments have shown that the hyperactivity of B lymphocytes is partly intrinsic and partly under the control of T cells and of humoral factors. A stimulation of T helper cells and an inhibition of suppressive T cells have been demonstrated by functionnal experiments as well as by the study of cells surface antigens.

Increased in vitro production by mononuclear cells of cytokines such as I12 or I14 might play a direct or indirect role in the stimulation of B cells.

Cytokines could also be involved in the glomerular injury since increased urinary concentrations of I16 are directly correlated with histological progression. Although plasma concentrations of the different components of the complement system ere generally normal in IgANs, a systemic activation is suggested by increased plasma concentrations of C3 degradation products (C3d, iC3bi-C3d) taking place during hematuria episodes and associated with extensive histologic lesions. Moreover, a deficit of solubilization of IgA-CIC by the complement system has been demonstrated. Immunogenetic factors certainly contribute to the development of the immunological abnormalities found in IgANs.

Indeed, parents of patients often display an increase of IgA production by their lymphocytes in vitro. Moreover, a particular polymorphism of the immunoglobulin heavy chain switch region as well as an increase frequency of homozygous C4B nul, C3FF and BfFF phenotypes have been observed. The direct pathogenetic role of the IgA abnormalities noted in IgANs remain questionnable since they can be observed in individuals presenting with no renal signs. Moreover, IgA is a weak activator of complement and isolated glomerular IgA deposits -without IgG or IgM -do not generally induce histological lesions in experimental models. However, IgA molecules located in CIC containing also potent activators of the complement cascade -as IgG, IgM or antigens -may contribute to glomerular injury by favouring the renal deposition of the latter complexes by several ways : 1 ~ a decrease of the CIC clearance by the C3b-H function of the phagocytic mononuclear system ; 2 ~ an increase of CIC size ; 3 ~ an increase binding of CIC to renal leetins through IgA oligosaccharidic chains. IgA nephropathy is a leading cause of chronic renal disease and end-stage renal disease in adult patients, and recent long-term studies assessing the prognosis in children have challenged earlier views that IgA nephropathy represents a benign disorder. Thus IgA nephropathy presents a therapeutic challenge in both adults and children. Prospective multicenter therapeutic trials of specific treatments for IgA nephropathy in children are in progress in Japan. A purpose of our study is to treat children with IgA nephropathy early in the course of disease. Early detection and successful therapy is one of the major goals of our study. We started this study in March, 1990 and 130 children with IgA nephropathy have entered the trial. All patients had initial renal biopsies after 1990 and had no treatment before biopsy. We divided these patients into those with diffuse mesangial proliferation and those with focal or minimal mesangial proliferation based on light microscopy finding. Sixty patients with diffuse mesangial proliferation were randomized into the 2 treatment groups. Prednisolone, azathioprine, heparin-warfarin and dipyridamole have been given in the group 1, and heparin-wartarin and dipyridamole have been given in the group 2. The duration of treatment is 24 months in both groups. The mean time of the start of treatment from onset or discovery of urinary abnormalities was 10 months. Interim results show significant reduction of urinary protein excretion in group 1 patients, but no reduction in group 2 patients. These data suggest that long-term glucocorticoid treatment combined with immunosuppressive, anticoagulant and antithrombotic drugs may be of benefit in those with evidence of disease of relatively short duration.

There is no evidence from adequately controlled studies that any specific treatment affects the course of Henoch-SchSnlein nephritis. In view of the natural history of the condition, the use of potentially dangerous drugs can be justified only for those with a severe renal presentation. We examined the effect of corticosteroids, cytotoxic drug and anticoagulants retrospectively in 22 patients presented with acute renal insufficiency. Of the 3 patients received no such drug, 2 progressed to chronic renal failure. Five patients were treated with prednisolone and/or cyclophosphamide, but 3 progressed to chronic renal failure. Seven patients were treated with methylprednisolone pulse therapy, but 5 progressed to chronic renal failure. In contrast, of 7 patients treated with combinations of anticoagulants, prednisolone and cyclophosphamide, only 1 progressed to chronic renal failure. Although the number of patients was too small to conclude the benefit of the combined therapy, our results indicate that a controlled therapeutic trial of the combined therapy should be initiated. C 89 S-26.1 Cisplatinum nephrotoxicity in the rat model and its prevention K.J. Ullrich*, U. Ammer*, and Yu. Natochin # *Max-Planck-Institut ftir Biophysik, Frankfurt am Main, #Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg.

We have investigated the effect of i.p. cisplatinum (CP) injection into male Wistar rats in the presence or absence of "protecting substances"-such as probenecid (prob), glycine (gly), diethyldithiocarbamate (DDTC), Nmethyl-D-glucamine-dithiocarbamate (NAG), and mercaptosuccinate (MS) 1.) on body weight, 2.) urinary inulin excretion, 3.) urinary sulfofluorescein (SF) excretion and 4.) renal tissue sulfoflu0rescein accumulation. Five days after i.p. application of CP (5 mg/kg b.w.) the following effects were observed: 1.) Body weight was reduced by 10 % as compared to a 12 % increase in control animals. Weight loss was diminished somewhat in the presence of all "protecting substances" except DDTC. However, only NaG had a significant preventive effect on weight loss when given simultaneously with CP. 2.) Inulin excretion was reduced by 50 %. For protection was the pattern the same as for the prevention of weight loss. 3.) Sulfofluorescein excretion in the urine was also reduced by 53 %. Again all substances tested prevented this effect of cisplatinum to some degree. However, only NaG and MS prevented reduction significantly. 4.) Accumulation of SF in cortical tissue was augmented. This effect was prevented by all protecting substances except DDTC. 5.) Paraaminohippurate (PAH) and sulfate uptake was not changed significantly while uptake of succinate into tubular cells was somewhat elevated, possibly due to starvation.-In acute uptake test CP, transplatinum, carboplatin, and cycloplatam interacted neither with contraluminal PAH-transport nor Nl-methylnicotinamide transport.

The data indicate that CP reduces GFR. Parallel reduction of SF excretion is not caused by impairment of the renal anion transport systems but supposedly by reduction of renal blood flow and/or of supply of SF exchange substrates. The effect of "protecting substances" on CP nephrotoxicity is seen in the effect on body weight and on kidney function. It is apparently not caused by effects on renal transport of CP itself but rather by complex formation of Pt whereby NaG seems to be the most efficient protecting substrate. Accumulating evidence exists about the potential long time nephrotoxie effect of IFOSFAMID fIFO) after successful treatment for s~vexe malignancies in children (1, 2) . The full clinical picture presents as a FANCONl-syndrome with Hyporanfinoaciduria, Glucosuria, Renal ttthular acidosis mad development of rickets as a result of disturbed phosphate reabsorption. In an retrospective study of 240 patients of the German Oncology Group (GPO), 6 month to 2 years after cytostatie treauncm, the complete clinical picture with FANCONI-syndrome was present in 5 patients, with partially severe renal insufficiency. In the overall analysis the phosphate reabsorption was disturbed in 5 to 25 % and Glucosuria was present in 3 to 35 %, depending on the kind of malignancy. These minor tubular abnormalities were present without clinical symptoms. In a prospective series of 27 children with various malignancies IFO was investigated in its effect on acute nephrotoxieity. All patients were treated according to various treatment protocols, exclusive Cispla~mm. In all treatment courses significant increases of urine excretion of proximal renal tubular enzymes (N-Aeetylglo~scami.nidasr ('NAG), a-Aminol~pti 'dase (AAP) as well as microproteins (anmicroglobuli~, fJ-2microgtobilin) was noted. Within one to three days these values canoe back to normal levels, even after repeated treatment courses. Tltis result seems to indicate, that the investigated acute toxicity parameters of the proximal tubal are no reliable predictors for long time toxicity. Distal tubular toxicity investigat~ by the excretion of Tamm-Horsfall-Protein (THP) was in no instance changed compared to normzl levels.

hl an attempt to study the mechanisms involved in the pathogen~is of this nephrotoxicity, WO and Cyclophosphamide metaholites like 4-OOH-IFO and 4-O0-CP and Acrolein were applied to a confluent layer of ren'.d epithelia! cells (LLCPK1). In addition to the eytostatie etf~t proven by thymidinr and ufidine incorporation, it could be shown, that sodium dependent glucose transport, the aminoacid transport and the phosphate transport were inhibited by these substances. Recent clinical studies implicate, that the neph.rotoxicity of IFO developed mainly in patients, who have experienced a combinado, of IFO and Cisplatinum. This seems to indicate the potential additive toxic effect. Single ease reports demonstrate that a definite renal toxicity long time after cessation of cytostattc treatment can progress to severn, renal insufficiency without therapeutic chances. Preventive measures are based on the ongoing analysis of the causes. In a eonsel~sus conference 1991 (3) the following risk factors lmve been suspected to be most probable: Very young age,lFO-treatment in combination with Cisplatinum, irradiation, single kidneys, accumulative doses of IFO (more than 90 g/kg). In an ongoing attempt to analyse the mechanisms involved and to develop definite accurate risk factors, it may be soon possible to give recommendations for preventive procedures. In a model of chronic cyclosporine nephrotoxicity, we have demonstrated that CsA treatment causes renal vasoconstriction, impaired RBF autoregulation, and abnormalities in the renin angiotensin system (RAS) characterized by a marked hypotensive response to acute inhibition of the RAS, and elevated PRA and renal renin content. To explore a possible association between the renal functional and RAS abnormalities, we examined renin distribution and measured microvasenlar responses to perfusion pressure (PP) and angiotensin II in blood perfused, juxtamedullary vessels in vitro. Pair-fed rats rseeived 25 mg/kg/day CsA s.c. or vehicle for 19-23 days. Responses of terminal juxtaglomerular (jAA) and mid-afferent arteriolar (mAA) segments were measured. PP was increased from 60 to 140 mmHg in 10 CsA and 13 control (CON) kidneys. A consistent finding was the marked thickening of arteriolar walls in the CsA rats. Autoregulatory responses were impaired by CsA. In the jAA, lumen diameter decreased by 37+3% (SE) in CGN, vs 95:9% in CsA. In the mAA, diameter was reduced by 34+4% in CON vs 185:6% in CsA. At 60 mmHg, CsA vessels were unresponsive to All (l riM): jAA diameter decreased by 245:4% in CON vs 2+4% in CsA. However, AII partially restored the autoregulatory responses in both segments.

To identify renin-containing segments along both superficial and juxtamedullary AAs, quinacrine, a non-specific fluorescent probe for renin storage granules, was applied intravenously (2 mg/kg one hr prior to study) to mark renin-positive cells. JM AA were examined for fluorescence during perfusion in vitro. Superficial enrtical (SUP) AA were dissected after HCL maceration. Fluorescent, renin positive regions in the jAA and mid-AA (mAA) were identified and recruitment was quantified. In JM CsA vessels, the length and extent ofjAA staining was significantly increased, and the extent of mAA staining was enhanced. In SUP CsA vessels, the length and extent ofjAA staining were again elevated. In the mAA, the fraction stained vessels was significantly higher in CsA, a pattern different from that in JM mAA. In CsA, renin positive regions were also seen in some interlobular arteries. Hence, CsA induced extensive renin reeruitmant in the preglomemlar microvasculature, with the heaviest recruitment in the jAA. These results using quinacrine as a non-specific marker for renin storage granules are similar to our previous observations with a specific polyclonal anti-rat renin antibody hi JM AA. The association between the sites of renin recruitment and loss of vascular reactivity to peffusion pressure and All suggests a causal relationship in these pathophysiologic phenomena.

To ~.h~'actci~ze fu~hc~ ~h~ eff~t~ of CsA on the intrarenai expression of renan, the intrarenal distribution of renin and its mRNA were assessed by immunocytochemistry and in situ hybridization in 20 control and CsA-treated rats. The percentage of juxtaglomerular apparatuses eontahaing renin was higher in CsA (845:5.5 %) than in the CON (615:7 %) group. The length of renin immunostaining along AA was higher in CsA (74+5 ttm) than in CON (375:5 #m). In contrast, neither renin mRNA levels (Northern analysis) nor its intrarenal distribution were altered by chronic CsA treatment. To further characterize the renin isoform(s) present in CsA treated kidneys, kidney tissue homogenate was analyzed by immtmobloning of denatured samples separated by polyaerylamide gel electrophoresis (SDS PAGE) or by analytical isoelectric focusing (IEF). The estimated molecular weight of immtmoreactive renin separated by SDS PAGE in CsA and CON kidney homogenate was similar (MW range 47,000-53,000 Da). However, immunoreaetive ranin separated by IEF showed the presence of an additional acidic isoform (pI 5.45:0.1) in CsA kidney homogenate not found in CON kidney homogenate (isoforms pI 6.25:0.2 and 5.7 5:0.1). Thus, CsA 1) causes loss of juxtamedullary AA reactivity and AII responsiveness, 2) induces recruitment of renin-containing ceils along the AA; 3) causes no change in renin mRNA levels or distribution; and 4) induces the production of an acidic isoform of renin suggesting that post-translational events may be responsible for the generation/or accumulation of renin(s) in the preglomerular mierovasculzture. It has been known for many years that a rapid increase in remnant kidney size occurs following unilateral nephrectomy (UNX).

However, the mechanisms that govern this accelerated rate of kidney growth have not been clarified. Furthermore, although there appear to be age-related differences in the rates and types of growth (i.e. relatively more rapid and hyperplastic increase in renal mass in young vs. slower, hypertrophic growth in adults), the changes are not well-defined. Recently, our laboratory has focussed on the possible role of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis in this process, because of the growth-promoting effects of GH and the evidence that the presence of the anterior pituitary is required for a normal compensatory renal growth. In the first series of experiments plasma GH levels were determined over a 6 hr period in conscious, unrestrained shamoperated and UNX adult (14 week old) and weanling (27-28 days) male Wistar rats. Within 24 hr of UNX, the puisatilc release of GH increased 3-to 4-fold in adult rats (/'<0.05). Moreover, when pulsatile GH secretion was suppressed in UNX rats, with an i.v. injection of a synthetic peptide antagonist to GH-releasing factor (GRF-AN: [N-Ac-~ft1-A~g2]-GRF-(I-29)-NH2), compensatory renal growth was significantly attenuated (by 66%, P<0.05) in the adult remnant kidneys 24 hr post-UNX. In contrast, plasma GH levels were not elevated in weanling rats 24 hr post-UNX, and preferential renal growth was still observed in young rats treated with GRF-AN (65• which did not differ from remnant kidney growth seen in saline-treated UNX rats (69*-5%). The increase in renal growth in immature GH-suppressed rats occurred despite a significant reduction in body weight gain. These findings suggested that the initial phase of compensatory renal growth is GHdependent in adult rats and GH-independent in weanling rats. To further test this notion, experiments were performed to assess the genetic expression of the renal GH receptor (GHR). RNA was extracted from control and remnant kidneys (24 hr UNX) by the guanidium-isothiocyanate/CsC1 method, and the integrity of RNA was confirmed by analysis of the ethidiumbromide stained 18S and 28S ribosomal RNA bands. Solution hybridization/RNase protection assays were performed on 20/.~g of RNA from each control and remnant kidney using a 32P-labeled antisense riboprobe for the GHR mRNA. Levels of GHR mRNA were elevated (3fold above controls) in adult, but not weanling, remnant kidneys. These results provided further evidence for the GH-dependence of compousatory renal growth in adult rats. We next evaluated the IGF-I component of the axis. Using antisense riboprobes in solution hybridization/RNase protection assays, renal IGF-I and IGF-I receptor (IGF-IR) gone expression declined in adult remnant kidneys, but increased 3-to 4-fold in remnant kidney from immature rats. The changes in renal IGF-I mRNA were confirmed by/n s/tu hybridization and localized primarily, but not exclusively, to the inner stripe of the outer medulla. Associated with the increase in IGF-IR mRNA levels in remnant kidneys from weanling rats was a 47% rise in binding of t2sI-IGF-I to renal plasma membranes (P<0.05), which was localized to the cortical region of the kidney. These studies indicate that there are differential mechanisms governing compensatory renal growth in weanling and adult rats. Although GH and IGF-I appear to be involved, the axis is dissociated in this paradigm. Compensatory renal growth in adult rats appears to be GHdependent with an increase in GHR gene expression hut independent of IGF-I, whereas compensatory renal growth in the weanling rat is GHindependent, but associated with significant increases in renal IGF-I and IGF-I receptor gone expression, as well as increases in specific IGF-I binding.

To what extent the selective dependence of different aged rats on either GH or IGF-I represents an important element in the mechanism underlying the beterotypic pattern of compensatory renal growth (hypertrophy vs hyperplasia), is a central issue that remains to be elucidated. Background: Dopamine (DA} is an intrarenal natriuretic hormone. The proximal tubule (PT) cells are the main source of DA. L-DOPA enters PT cells and is converted to DA by the enzyme aromatic L-amino and decarboxylase (AADC). DA acts natriuretically by inhibiting the activity of Na+,K+ATPase (NKA) in several tubule segments. Inactivation of NKA activity is due to phosphorylation of the catalytic e subonit of the enzyme. The effect involves activation of the D1 receptor, activation of cAMP-dependent protein kinase and activation of a DA and cAMP regulated phosphatase inhibitor, DARPP-32. In some cell types activation of the D1 receptor only is sufficient to inhibit NKA activity (example thick ascending limb, TAL, Henle cells). In other cell types NKA activity is inhibited by a synergistic action of the D1 and D2 receptors (example PT cells). Ontoaenv of renal dooamine system in rats: We have with immunohistochemistry located AADC to PT cells. AADC is present already in the fetal kidney, and the expression of the enzyme appears to reach a peak around 20 days el age (weanling period for rats). DA activation of adenylate cyclase and inhibition of NKA activity increases with age in PT cells. DA activation of adenylate cyclase and inhibition el NKA activity decreases with age in TAL cells. Several lines of evidence indicate that DA might play a role for cell differentiation. We have examined the presence of DARPP-32 in the fetal, infant and adolescent kidney. In the fetal kidney DARPP-32 is very abundant in the ureter bud and is also present in the mesenchymal cells surrounding the ureter bud. When nephrogenesis is completed, around the 8th postnatal day, the DARPP-32 signal fades to reappear in late infancy and reach a peak in the adult kidney In the adult kidney, DARPP-32 is present both in PT and TAL cells. Both immunohistochemistry and immunoblotting indicate a higher abundance in TAL. The non-specific phosphatase inhibitor, inhibitor-I, is not present to any larger extent in the tetal kidney, but is co-localized with and generally more abundant than DARPP-32 in the adult renal tubule cells. Conctusion: The dopamine system is present both during nephrogenesis and in tubular cells of the mature kidney, indicating that DA may be of significance both tor kidney differentiation and for regulation of tubular Na+ transport. The renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure, renal hemodynamics, glomerular capillary pressure and tubular ions transport. Numerous studies have been devoted to the analysis of the RAS during kidney entogenesis. The juxtaglemerular apparatus (JGA) differenciates in tight association with the developing nephrons and may be identified from the late S-body stage in the first metanephrons of 8 week old fetus. Renin has been detected from the 5th week of the intra-uterine life in human mesonephros. In the metanephros, the first renin-positive cells are detected in the absence of fully developed JGA. The distribution of renin and its mRNA shifts with maturation from large intrarenal arteries to the classical juxtaglomerular localization (1). The distribution of angiotensin-I converting enzyme (ACE) is also developmentally regulated. In fetal kidneys it is expressed on the apical and basolateral membranes of proximal tubular cells, before the differenciation of brush borders, and on glomeruiar endothelial cells as soon as the capillary invades the inferior cleft of the S-shaped body. Conversely in post-natal kidneys, ACE is found in endothelial cells of peritubular capillaries and progressively disappears from glomerular endothelial cells (2), Angiotensinogen (Ao) is present in proximal tubular cells of developing nephrons (2) . Its renal synthesis has been demonstrated by molecular biology techniques (3). Angiotensin II receptors have been ~shown to be present in kidneys of late gestation rat fetus but also in areas not normally expected to contain angiotensin II receptors (4) . Therefore, all the components of the RAS exist within the fetal kidney and may contribute to the control of intrarenal hemodynamics as in the adult kidney. In addition, it has been suggested that angiotensin II, which stimulates angiogenesis, is important in the glomerular growth of maturing kidney (2, 5) . Dysregulation of the RAS may be observed in developing kidneys in various pathologic conditions. Experimenta! studies have shown increase in renin content and renin gene expression in developing kidneys subjected to ureteral obstruction (6) . in 2 anuric neonates exposed to ACE inhibitors during pregnancy, we observed a marked increase in the number of kidney renin-positive cells, associated with severe tubule-interstitial lesions. Although this complication is rather rare (7) close surveillance of fetal urinary output and post-natal renal function is necessary when ACE inhibitors have to be prescribed during the last weeks of pregnancy. In anuric neonates whose mothers had been treated with indomethacin (ID) because of preterm labor or polyhydramnios, increase in renal renin was detected by immunohistochemistry. It was associated with ischemic changes of the deep cortex and more or less extensive cystic dilatation of superficial nephrons (8) . The increase in immunoreactive renin suggests that prior stimulation of the RAS could favor the appearance of renal failure in fetus exposed to prostaglandin inhibitors treatment.

Because of renal (and extra-renal) side effects, the use of ID, during pregnancy, is only justified during a few days, under daily monitoring of amniotic fluid production. Two anuric neonates and 3 fetus with unexplained oligoamnios had renal changes characterized by lack of differenciation of proximal convoluted tubules. In the 5 patients, immunohistochemical study of renal renin distribution showed a massive staining of juxtaglomerular ceils with extension of the afferent arterioles labeling toward the interlobular arteries and with recruitment of most mesangial cells. This finding suggests that the RAS in involved in the pathogenesis of the socalled "Renal tubular dysgenesis", an abnormality of kidney development which seems to be transmitted as an autosomal recessive trait (8) . 

The immature kidney is often faced with conditions unfavorable to its intrauterine development and to its adaptation to extrauterine life: intrauterine hypoxia, perinatal asphyxia, severe respiratory disturbances secondary to pulmonary immaturity, congestive heart failure secondary to patent ductus arteriosus, neonatal pulmonary hypertension. All these conditions can lead to renal insufficiency and failure. The vasoactive agents used in high-risk neonates can also stress the immature kidney whose perfusion and glomerular filtration are extremely labile. Most of the conditions that affect renal function do so by increasing the renal vascular tonel leading to renal hypoperfusion. Maintaining or restoring cardiac output, while decreasing the renal vascular resistance, is the best way to protect the kidney. This can be achieved by normalizing the homeostasis of body fluids composition and volume. Adequate ventilation and careful correction of the acidosis are also mandatory.

Hypoxemia commonly occurs in the neonate presenting with respiratory disturbances. Hypoxemia activates vasoactive forces that increase the renal vascular resistance, thus leading to the so-called vasomotor nephropathy. Experiments have been performed in newborn anesthetized rabbits to better define the vasoactive forces that are activated during hypoxemia, and to explore ways of preventing the occurrence of the vasomotor nephropathy. At the glomerular level, vasoactive agents vasoconstrict (angiotensin II) or vasodilate (adenosine) the efferent arteriole, while the combined effects of angiotensinII and adenosine result in afferent vasoconstriction. Circumstantial evidence indicates that endothelin also participates in the hypoxemia-induced renal vasoconstriction: a) the intravenous infusion of endothelin to normoxemic animals produces renal hemodynamic changes reminiscent of those induced by the hypoxemic stress, and b) the renal hemodynamic changes normally observed during a hypoxemic stress are partially blunted when a endothelin-1 antiserum is administered before the stress. The worsening of the renal response to hypoxemia in animals pretreated with indomethacin suggests that the prostaglandins play a role in protecting the stressed kidney. Also, the increase in RBF induced by hypoxemia when the release of angiotensin II and adenosine is inhibited by the administration of converting enzyme inhibitors and theophylline, respectively, suggests that nitric oxide could be released during hypoxemia to protect the stressed kidney.

While dopaminergic agents (dopamine, dopexamine) do not appear to prevent the hypoxia-induced vasoconstriction, several agents such as low-dose theophylline or the thiophosphate WR-2721 (a recently synthetized hypocalcemic agent with O2-free radical scavenging properties) appear to provide substantial protection to the kidney during a hypoxemic stress. We have previously demonstrated that P depletion and euparathyroid vitamin D deficiency induce a taurinuria which is associated with reduced Na*-dependent T uptake by renal proximal tubule brush border membrane vesicles (BBMV) and decreased affinity of the T symport. We studied the effect of P depletion and D deficiency on the stoiehiometry of the T-Na+-CI" cotransporter in the proximal tubule. Male Sprague-Dawley rats were fed one of the following diets: I) CON (0.7~ P, 5.5 ~g~ D); 2) D*P" (0.I~ P, 5.5 #g~ D); D'P + (0.7~ P, 0 #g~ D). All diets contained 1.2~ Ca. A group of rats fed D'P + were supplemented with 500 pmoles of 1,25[OH]2D , IM, one day prior to sacrifice (SUPP). T uptake by BBMV was assayed in the presence of various concentrations of external Na + or CI" at 15 sec. P depletion resulted in a 1.7-fold increase in plasma Ca and a 3.6-fold decrease in plasma P compared to CON (p<O.001 # pmoles/mg protein/15 sec. We conclude that P depletion and vitamin D deficiency effect a stoichiometrie change in the T symport which involves Cl" and spares Na § We speculate that this alteration may reduce the affinity of the T cotransporter in the proximal tubule with consequent taurinuria. Introduction: Little attention has been paid to interplay among calcium, magnesium, parathyroid hormone and vitamin D in primary renal tubular hypokalemic alkalosis and hypomagnesemia with hypocalciuria (Gitelman syndrome). This tubular disorder has been often confused with classic Bartter syndrome and presents with tetanic crises complicating the course of febrile respiratory diseases in schoolchildren and adolescents. The diagnostic laboratory criteria include normal blood pressure, venous blood pFi >7.38, plasma bicarbonate >28s mmol/1, plasma magnesium <0.75 retool/l, and molar ratios of urinary calcium to ereatinine <0.20, urinary chloride to creatinine >8.50, and urinary magnesium to creatinine >0.15. Study design: Plasma and urinary electrolytes, and intact parathyroid hormone (two site immunoradiometric assay) and metabolites of vitamin D (25(OH)-Ds and t,25(OH)2-D3) in blood were studied after overnight fast in 13 untreated Gitelman patients aged 10-17-21 years (ranges and median) and 13 healthy controls aged 16-18-20 years. Various studies differ considerably in their assessment of proteinuric patterns in the course of transplant malfunction. Especially the differentiation between cyclosporine (CyA) toxicity end acute rejection has been a major problem. 734 urine samples from 38 patients after kidney transplantation were examined by gradient gel electrophoresis (SDS-PAGE) with consecutive Coomassie Blue (CB) and silver staining. ~22 histologically proven rejections and 20 CyA overdosage episodes were diagnosed in these patients. No changes in proteinuric patterns were seen in 9 of 22 patients after CB stain, whereas silver stain revealed a typical rise of glomerular protein bands in 19 of 22 cases. Discrimination between CyA overdosage and rejection was possible with a probability of p<O.O01 after silver stain. Secondly IgG, transferrin (TP), albumin (Alb), -microglobulin (M -MG), D2-microglobulin (D2-MG) were determined daily in 24h-urine samples of 127 allograft recipients using immunoluminometric assays. Ouring 64 rejections (both vascular and interstitial) a sudden rise in "glomerular" proteins (IgG, TF, Alb) could be seen with no changes in "tubular" proteinuria (~-MG, ~2-MG). Acute CyA toxicity showed no changes in the excretion of urinary proteins in 5 patients. Our findings suggest that application of highly sensitive silver stain instead of the conventional CB stain after SDS-PAGE and the daily determination of specific urinary proteins by immunometric assays offer considerable progress in monitoring renal transplant recipients. With the exception of supportive measures, modal• used to treat acute allograft rejection (AR) aredirectedat modulation of the immune system. Initially AR is characterized by per• vascular infiltration and ischemia consequent to cortical vasoconstriction. Because sANP increases intrarenal perfusion in states of vasoconstriction and alters glomerular capillary Starling forces to promote increased filtration, this study was undertaken to determine if administration of sANP lessens the severity of the vasomotor nephropathy caused by early AR. Seven mongrel dogs underwent unilateral nephrectomy and allotransplantation without immunosuppressive therapy.

On POD #3, the allograft was mobilized under anesthesia and two consecutive30 min. clearance collections (period I and II) were obtained for determination of glomerular filtration rate (GFR) by inulin clearance. Mean arterial pressure (MAP) and hematocrit (HCT) were measured during both collection periods. Animals received normal saline vehicle (VEH) during period I and sANP (ohANP) during period II (l.Omcg/kg i.v. bolns § Joy.x30 min). Following period II both the allograft and the native kidney (NK) were excised, weighed, and biopsied. Results are reported as mean+SEM. MAP declined during sANP infusion (131 mmHgJ6 § I12+7 mmHg,p<.05) and HCT remained unchanged (34~2 § ~2,p=NS). Per• interstitial infiltration was present in 7/7 allografts. 4/5 NK were free of interstitial infiltration with rare foci in the 5th. Allografts were enlarged with a mean weight of 130+7 gms. Mean weight of the native kidneys was 75+6 gms (p<.O5 vs. allografts). Effects of sANP on allograft urTne flow rate (V) and GFR are tabulated below:

Period During recent years cytokines have been found to play an important role in the pathogenesis of human inflammatory diseases. Cytokines are released upon stimulation of bacterial products such as LPS (endotoxin) from Gram-negative bacteria. These cytokines than mediate many of the inflammatory responses seen as e g increased vascular permeability, chemotaxis, fever and increased CRP. In this study we used ELISA assays to measure the two inflammatory cytokines interleukin 6 (I1-6) (Medgenix diagnostics) and interleukin 8 (I1-8) (British Bio-technology Limited) in the urine from newly admitted children between 0-7 years of age with acute first-time non-obstructive pyelonephritis. Children of the same age with fever of non-renal origin served as controls. I1-6 was detected in the urine of 58% of the children with acute pyelonephritis but only in one child with non-renal fever. I1-8 was detected in the urine of all children with pyelonephritis, median 300 pg/ml (range 68->2000 pg/ml). In only one child with nonrenal fever I1-8 could be detected in the urine at a concentration of 70 pg/ml. Conclusion: The presence of I1-8 in the urine seems to be a good indicator of pyelonephritis in children. Further larger studies are needed to verify our data. The effects of the drugs, CsA and FK on monocyte functions am controversial and not well understood. We have been using THP-1, a human monocytic leukemia cell line to study the effects of these drugs in comparison to DEX on rnonocyte functions. We have examined the ability of these drugs, alone and in combination, to suppress rnonokine production in vitro by THP-1 cells stimulated by lipopolysaccharide, CsA added in increasing concentrations of 50-1000ng/ml suppressed IL-lbeta from the control of 857+198 (mea +n~SE) to 314-'l:137pg/ml but increasing concentrations of the drug greater than 50ng/ml had no further significant suppressive effect on IL-1 production. In the same manner FK added in concentrations of 1-10ng/ml suppressed production to 352+-126pg/ml but increasing the concentration of FK above lng/ml did not increase suppression of IL-1. DEX added in concentrations of from 0.1-100OHM did, however, decrease production of IL-1 in a dose dependent fashion from the control level to undetectable levels. FK was then added in increasing concentrations (O-4ng/ml) to 250ng/ml of CsA but it did not further suppress IL-1 production below thai caused by CsA alone. In the same way when ~ was added in increasing concentrations (0-500ng/ml) to 2ng/ml of FK, the mean IL-1 production did not change, DEX added in increasing concentrations (0-100nM) to either ~A or FK further suppressed IL-1. The addition of 100 ng/ml CSA or lng/ml FK to 100riM DEX suppressed IL-1 productiOn more than DEX alone, but further increases in the Concentrations of either CsA or FK caused no further suppression of monokine production. These data suggest that FK and CsA suppress IL-1 production by the same mechanism and that DEX works-by a different mechanism. Further studies may contribute to out understanding of mo,ocyte physiology. To determine if such effect is also present in vivo, we evaluated renal potassium excretion in 49 children with idiopathic hyperealciuria (UCaV = 5.5 + l.S mg/kg/day) and in 214 age-matched control children (UC~V = 1.9 + 0.3 mg/ kg/day). In comparison to controls, hypercalciuric children had significantly increased levels of sodium excretion (FENa = 0.7 + 0.3 % vs 0.6 + 0.3 %, p ~ 0.001) and decreased levels of frac{ionsl potassium excretion (7.2 + 2.9 % vs 9.2 + 3.4 %, p < 0.001), urinary potassium concentration to urinary sodium concentration (0.4 + 0.2 vs 0.6 + 1.0, p ~ 0.001) and transtubular potassium concentration gradient (4.2 + 1.5 vs 5.9 + 1.5, p < 0.001). After an oral calcium load, carried out according to the Pak protocol in SO hypercalciuric children, the increased rates of urinary calcium excretion (UCaV = 0.07 + 0.05 @ 0.20 + 0.ii mg/dl GF) were accompanied by increasedrates of urinary sodium excretion (FENa = 0.6 + O.S ~ i.I + 0.7 %) but by a significant decrease in transtubular potassium concentration gradient (8.6 + 2.7 ~ 6.5 ~ 3.1). All indices of potassium excretion correlated significantly and inversely with urinary calcium excretion (p<O.O01). These results support the conclusion that increased luminal calcium concentration also inhibits renal potassium secretion in man, probably by decreasing sodium conductance at the apical membrane of principal cells of distal and cortical collecting tubules, and thus decreasing the electrochemical driving force for potassium secretion. The observed increase in sodium excretion following a calcium load puts also into question the accepted interpretation that, when increased rates of both substances are present, hypercalciuria is secondary to increased sodium intake. The present results support the reverse conclusion that the hyperna~riuria is secondary to hypercalciuria. The natriuretic and diuretic effects observed after the administration of pyrogenic agents or endotoxin could be mediated by cytokins. In the rabbit, the systemic acute injection of human recombinant Interleukin-1 (/L-l) induces significant increases in urine flow and sodium excretion rates, along with marked decreases in systemic mean blood pressure (MBP) and glomerular filtration rate (GFR). The natriuretic and diuretic renal response to IL-1 could be due to a) a systemic effect of the cytokin, or b) a direct renal effect of the cytokin on tubular reabsorption. These hypotheses were tested in pentobarbital-anesthetized mechanically-ventilated rabbits undergoing standard inulin and PAH clearance studies. After a control period, experimental animals (n=10) were injected IL-113 (100 ~tg) in the left renal artery, while control animals (n=9) received the vehicle only. The intrarenal injection of IL-113 increased rectal temperature by 0.8~ but did not alter MBP, GFR or PAH clearance in the 2 hours following the injection. By contrast, urine flow rate and the fractional excretion of sodium (FENa) increased significantly as compared to the control period (diuresis: +29%, p<0.01; FENa: +51%, p<0.05) or to the controlateral kidney. There was no change in any of the measured parameters in the vehicle-injected control group. In contrast with the systemic injection, the intrarenal injection of ILl[3 did not result in an increase in the urinary excretion of PGE 2. We conclude that IL-1 directly inhibits the tubular reabsorption of sodium and water in the rabbit. The increased PGE 2 synthesis which occurs after the iv injection of IL-1 does not mediate the/L-l-induced natriuresis. Familial juvenile nephronophthisis (NPH), an autosomal recessive disease, is the commonest genetic cause for end stage renal failure in children. We are trying to map a gene for NPH by linkage analysis as an approach towards a molecular characterization of the genetic defect.

From 2 families with NPH and 3 families with Senior-Loken syndrome (NPH with retinitis pigmentosa) with the typical history and clinical signs of NPH, blood samples were obtained and genomic DNA was extracted using a standard protocol. Oligonucleotide primers for microsatellite-PCR markers (MS-PCR markers) of known chromosomal location were synthesized for use in the polymerase chain reaction (PCR). Heterozygosity indices of most of the MS-PCR markers were 0,65 -0,95. PCR products were amplified from 20 ng of genomic DNA using a standard PCR protocol, separated on a polyacrylamide gel and detected by autoradiography. LOD scores were computed with the LINKAGE program.

115 highly polymorphie MS-PCR markers were examined by multiplex-PCR. In spite of the relatively low number of families available, linkage could be excluded from 41 MS-PCR markers (LOD <-2; theta=0,05-0,10), assuming genetic homogeneity of NPH and SLS. Conclusions[ 1. MS-PCR-markers exhibit several advantages over classical RFLP markers with respect to informativity, speed of genotyping, and amount of genomic DNA required. 2. In 5 families with NPH/SLS we were able to exclude the disease from 14% of the human genome (LOD < -2) under the assumption of genetic homogeneity. 1985 -78%, 1986 -76%, 1987 -76%, 1988 -70%, 1989 -54%, 1990 -50%. Graft losses were associated with an increasing incidence of early, severe, steroid resistant rejection with histological features suggestive of antibody mediated rejection. Between 1985-1990 47 grafts have been lost, 17 (36%) were associated with the presence of AECA.

A strong correlation was found between the presence, at transplantation, of the antibody and graft loss (p<O.O01).

The presence of AECA was associated with regrafting, early rejection, multiple arteries on the donor kidney and an ~icreased incidence of vascular rejection histologically.

17/27 (63%) grafts positive for AECA at transplantatlon were lost.

The prevalence of AECA in graft recipients increased from 15% in 1985 to 35% in 1989, and in 1990 72% of children awaiting transplantation were positive for AECA.

The increase in graft loss that has occurred can be accounted for by the AECA associated graft losses. Studies in normal children in 1989/90 show a prevalence of AECA of 67%.

This has major implications for the management of children with chronic renal failure who are approaching transplantation. Ca++-dependen[ protein kinases are known to phosphorylate membrane-bound carrier proteins thereby modulating transporl of various solutes in the renal tubule. The role of these enzymes in the maturation of renal tubular transport processes is unknown. !qe investigated the developmental maturation of Ca+-+-dependent protein kinase activity and distribution in the rat kidney. The activity and endogenous substrates of Ca_+-+-and phospho]imd-dependent protein kinase (protein kinase C: PRC) and, the. activity of Ca ++-and calmodnhn-dependent protein, kinase (CaMK) were examined in me brush border membrane (BBI{) and eTtosol derived from kidneys of .7 day-old and adult rats. Hisione and syntide ]] (a synthetic peptide) phosphorylation assays were used to measure PKC and CaMK ae'tivity, respectively.

The pattern of PgC-dependen[ endogenous protean phosphorylation was examined using gel eleetrophoresis and autoradiography. .4 Ca++-dependent aetivtty of both kinases was demonstrated m the BBit and ey.tosol of immature and adult rats. h 65-85% inhibition of PKC and taNK activity in kidneys from both ages was induced by the specific kinase inhibitor peptides PKC 19 -31 One third of children with abdominal neuroblastoma (NB) requires nephrectomy (Nx) and their treatment (cisplatin, carboplatin, conditioning for marrow transplantation (MT)) represents a high risk for renal damage, whereas Wilms tumor (WT) treatment, associated with Nx, uses to be less nephrotoxic. We prospectively investigated renal function in 34 Nx children with regard to treatment nephrotoxicity and age at the time of Nx. 6 children, who underwent Nx for nonmalignant disease (normal contralateral kidney) served as controls (group C). Renal function study was mainly based on Cin (ml/min/1.73m 2) and Cpah (ml/min/1.73m2). The follow-up period after Nx was 3-70 months (median 9) for the NB group, 2-60 months (median 12) for WT group and 8-108 months (median 23) for the C group. No significant differences in Cin/Cpah (mean _+ SD) were found between NB group (90_+24/421_+95), WT group (85+17/386_+104) and C group (93_+13/430_+61). According to the theoretical nephrotoxic risk, children with NB and WT were divided into 2 groups Group NB1 included 6 children without MT (mean age at Nx_+SD=22_+12 months) ; in NB2 group (n=7, age 57_+50) all patients had MT + total body irradiation. Patients of group WT1 (n=13, age 24_+16) received drugs without any known nephrotoxic adverse effects ; patients of group WT2 (n=8, age 71_+47) were treated with local irradiation _+ ifosfamide _4-cis (carbo) platin. There was no significant difference in renal function (Cin/Cpah) between NB1 and NB2 (101-+24/467-+116 vs 80_+22/381_+55), nor between WT1 and WT2 (82-+9/367-+63 vs 89_+26/416-+151). Cumulative cisplatin doses in children with NB did not affect renal function significantly. Age at the time of Nx (_<2yrs vs >2yrs) is not associated with a higher risk of renal damage in WT children, whereas in NB children the filtration fraction is Ngher in younger children (mean_+SD : 0.243_+0.023 vs 0.191_+0.041, p<0.01).

In conclusion, uninephreetomized children with neuroNastoma are supposed to have a higher risk of drug-induced renal impairment when compared to Wilms tumor. Our data do not confirm this hypothesis since renal function is comparable to controls in both groups, except in younger patients with neuroblastoma who show a Ngh filtration fraction. As the survival of children with neurobla~stoma has improved, a longer follow-up of their renal function is needed. To compare the efficacy (maintenance of steroid induced remission of NS and steroid-sparing effect) and safety of CsA with those of Cyc in children with FR/SDNS an open, prospective, randomized, multicentric, controlled study for parallel groups was organized.

Fifty-five children were randomly assigned to be given Cyc (2.5 mg/kg/d) for 8 wks or CsA (5.6 mg/kg/d) for 9 men, then tapered off within me 12. rntercurrent relapses of NS were treated with PDN according to ISKDC. Forty-three children were followed-up 24 mos. The no. of relapses~patient~year and the mean PDN amount/year were evaluated during the year before randomization, the experimental year and the following year. Pre-pubertal children (13 in the CsA group and 12 in the Cyc group) were evaluated for their growth ~ith the Height Standard Deviation Score (hSDS) during the whole period. Changes in allograft function in pediatric renal transplarlt patients may be caused by acute rejection episodes, infection, eyelosporine (CSA) toxicity, obstructive uropathy, or recurrent gfomerular disease and may be difficult to distinguish by routine laboratory tests alone. Renal biopsy may be necessary in order to determine the exact cause of dysfunction. The use of specific surface markers for flow cytnmetrie enumeration of lymphocyte subsets can aid in the assessment of allograft status and may be useful to distinguish rejection episodes from CSA toxicity. Sequential studies are most valuable when carefully assessed along with clinical status and routine laboratory tests (BUN, serum creatinine, beta= microglobulin [B2MG] , and CSA levels).

Immunophenotyping results were obtained utilizing a panel of monoelonal antibodies and dual staining techniques. Over the past two years, sequential studies were obtained on 71 pediatric renal transplant patients of which 56 were first time transplants (49 living related donor and 7 cadaver donor transplants). Patients were studied 0.1 to 13 years post transplant. Twenty five patients required at least one biopsy for renal dysfunction. Eigh'~een patients showed mild to severe acute cellular and/or vascular rejection. These biopsied patients were all assessed with immunophenotyping panels. Although several markers are used in this assessment, the single most predictive parameter was the ratio of the CD4 + subsets [CD4 +,CD29 +:CD4+,CD45RA+] or the T inducers of help: T inducers of suppression {Tih:Tis). Tih:Tis increased over previous values obtained in these patients during biopsy proven rejection Imedian = 233% of baseline response, range = 133-400%, n = 18) as compared to patients .who did not have rejection (median = 93% of baseline response, range = 56-101%, n=7) (p<0.O01 by Mann Whitney U test). In fact al ._!l patients with rejection had an increase in Tih:Tis ratio, whereas only one of the non-rejecting group had a slight increase. In addition, this ratio decreased in parallel with the serum ereatinine and B~MG level after effective anti-rejection therapy. Changes in the CD4:CD8 ratio were no tt consistently altered during rejection episodes, but appeared to aid in diagnosing viral or bacterial infections, as has been found previously. When utilized in tandem, the CD4:CD8 and the Tih:Tis ratios are valuable additions to the follow up assessment of pediatric renal transplant patients, and, if used sequentially, may help predict rejection episodes. The diagnostic value of 99mTc-dimercaptosuccinuic acid (DMSA) scintigraphy, ultrasotlography and renal fimctional parameters (urine Naeetyl-B-D-glueosaminidase (NAG)/creatinine and urine albumin/ creatinine quotients) were studied in 39 children (11 boys, 28 girls; median age 9 mths, range 2 wks-9.4 yrs; <lyr: 28 patients; >lyr: 11 patients) with first-time acute pyelonephritis. The inclusion criteria were: 1. Urine culture >105 bacleria/ml; 2. Fever >38.50C; 3. CRP >20 rag/l; 4. No previous history of urinary tract infection; 5. No obstruction or duplex system. Ultrasound examination of the urinary tract was performed at admission and together with DMSA scintigraphy (<10 days from admission). Urine NAG/creatinine and albumin/creatinine quotients were analyzed daily, and after recovery (6-8 weeks) . DMSA uptake defects were present in 32/39 (82%) of the patients. In 7/28 (25%) children <lyr of age the DMSA scintigraphy was normal while all 11 children >lyr had changes (p=0.05). Ultrasonography revealed abnormalities in only 11/32 patients with positive DMSA scintigraphy. Urine NAG/creatinine and albumin/creatinine quotients were significantly higher in children <lyr of age with acute pyelonephritis, as well as in nonrenal fever controls, than in older children. In the younger age group (<1 yr) the urine NAG/creatinine and albumin/creatinine quotients, however, were significantly higher together with pyelonephritis than with non-renal fever. The urine NAG and albumin excretion had normalized at the 6-8 weeks' follow-up. The size and degree of reduced DMSA uptake (DMSA score) did not correlate with duration of disease at admission, maximum CRP or fever. Neither was there any correlation with urine NAG/creatinine and albumin/creatinine quotients in children >lyr of age. However, in the group <lyr the urine NAG/creatinine quotient showed a significant correlation with the DMSA score. We conclude that DMSA scintigraphy is a sensitive method to diagnose an acute pyelonephritis. Tubular parameters may further improve the diagnostics in the infant. The study was carried out to assess the possible involvement of AVP excess and free water retention in development of late hyponatremia by comparing the postnatal course of plasma level and urinary excretion of AVP & sodium as well as ereatinine osmolar & free water clearances in premature infants with (group S) & without (group NS) NaCI supplementation. Plasma total protein and albumin concentrations were also determined. Group NS consisted of 8 infants with a birth weight of 1150-1730 g (mean 1440 g) and gestational age of 28-32 weeks (mean 30.4 weeks). Group S included 8 infants with mean birth weight of 1390 g (range: 980-1700 g) and mean gestational age of 30.1 weeks (range: 27-32 weeks). Measurements were made on the 7th day and weekly thereafter until the 5th week of /lie. NaCI supplementation was given in a dose of 3-5 & 1.5-2.5 mEq/kg/day for 8-21 & 22-35 days, respectively. In group NS plasma sodium gradually declined from 142.5_+2.9 in 4-5 weeks (p<0.025) whereas in group S it remained unchanged. Fractional sodium excretion decreased with age in both groups; it proved to be significunfly higher when NaCI supplement was given (p<0.025). Plasma AVP tended to be higher in group S but did not differ significantly from that in NS group. Urinary AVP excretion, either expressed in terms of ug/day or ng/100 ml GFR was significantly higher in group S, although the age-related increase could not be seen when correction was made for GFR. ng/day (p<0.025) in group NS. NaC1 supplementation and the increased AVP excretion has no apparent influence on GFR, it was associated with significant decrease in free water excretion, plasma total protein and plasma albumin concentrations. These data suggest that NaCI supplementation prevents late hyponatremla at the expense of AVP-mediated free water retention and subsequent volume expansion. Renal function and morphometry of the progeny of rats submitted to 5~% dietary restriction (pair-fed with control group) throughout pregnancy (Rt group), during the first half of pregnancy (RI group) or during the second half of pregnancy (R2 group) were studied S months after birth. Glomerular filtration rate (GRF) and renal plasma flow (RPF) decreased significantly in all groups when compared to control (C)(GFR, 4.44+--0.12, 4.O4+-0.18 and 4.00+-0.16 vs 6.87+--O.17 and RPF, 19.06+-0.57, 17.00+1.14 and 13.31+0.50 vs 22.57+0.67 ~respeetively). Net acid excretion calculated per ml of GFR was either maintained or stimulated (RI group). A significant decline in the nt~nber of glomeFuli occurred in RI, R2 and Rt rats ( Hyperlipemia, a feature of nephrotic syndrome, may directly contribute to chronic renal injury. The present study investigated the ability of the lipid-lowering drugs probucol and lovastatin to modify the course of the acute tubulointerstitial disease in rats with nephrotic syndrome induced by purine aminonueleoside (PAN) We have previously shown that this model is associated with an interstitial influx of monocytes and an increase in renal steady state mRNA levels for transforming growth factor 81 '(TGFs several extracellular matrix genes (ECM), and the tissue inhibitor of metalloproteinases (TIMP) [J Am Soc NephroI 1:550, I990] . Focal interstitial accumulation of ECM proteins occurs at 2-3 weeks. Three groups were studied: A--PAN alone; B--PAN+probucol; C--PAN+lovastatin. Animals were killed on day 9. Albuminuria on days 5 and 8 was similar in all groups. Compared to group A, serum cholesterol and triglyceride levels were decreased in group C but not B. The number of interstitial macrophages (ED-1 +, Mar-1 +, Ia +) was similar in the three groups. Both lipid-lowering'drugs decreased renal mRNA levels for collagen I (38% and 34% of relative densitometric units corrected for RNA loading for groups B and C compared to group A respectively), collagen III (60% and 32%), fibronectin (16% and 9%), stromelysin (69% and 11%), and TIMP (61% and 47%). In addition, mRNA levels for TGF~ were reduced (47% and 29%). Kidney mRNA levels for glyceraldehyde-3phosphate dehydrogenase (GAPD), a constitutively-expressed gene, were similar in the three groups. These results suggest that lipidlowering drugs may decrease the renal accumulation of ECM by downregulating transcription of ECM and TIMP genes. Although the mechanism is unclear, this effect occurs despite persistent interstitial infiltration by monocytes and is not dependent on a significant reduction in plasma total cholesterol levels. We speculate that the inhibition of lipid peroxidation and the subsequent inhibition of TGF~ production play a central role. Recent evidence suggests that insulin resistance and hypertension may be pathogenetically related.

There is also evidence of pertubations of vitamin D metabolism in insulin resistant and hypertensive disease states such as essential hypertension, obesity and diabetes mellitus. The role of 1,25 DHCC in the pathogenesis of insulin resistance and hypertension is tested in a rat model of chronic renal failure. Male Sprague Dawley rats underwent 1 3/4 nephrectomy. 4 weeks after nephrectomy, chronic catheters were inserted into the jugular vein and carotid artery and metabolic studies were performed 1 week after catheter placement in the fasting state.

The mean serum creatinine in the uremic rats (UR) (mean body weight 280 • I0 gm) was 1.2 • 0.2 mg/dl (n=12) compared with 0.3 • 0.i mg/dl (p <0.01) in control rats of comparable weight. Four groups of 5-7 awake, unstressed, chronically catheterized rats were studied. Group 1 = UR without 1,25 DHCC (-D), Group 2 = UR with 1,25 DHCC (+D), Group 3 = controls (CON) -D; Group 4 = CON +D. 1,25 DHCC was given (at a dose equivalent to 2 mcgm/m z in humans) intraperitoneally in 2 divided doses daily for three days with a full dose intravenously in the morning, 2 hours prior to the clamp study.

Euglycemic hyperinsulinemic (4mU/kg.min) clamp studies were performed to quantitate insulin sensitivity. Insulin mediated glucose uptake (I) was reduced in UR-D (10.73 • 1.2 mg/kg'min) compared with CON -D (20.09 • 1.8, p <0.02).

1,25 DHCC increased I by 117% in OR +D (23.32 ~ 3.0 p<O.01) when compared with UR -D.

1,25 DHCC normalized I in UR. There was no significant difference in I between CON -D (20.09 • 1.8) and CON +D (23.34 • 3.2).

Mean intra-arterial pressure (MAP) was higher in UR -D (142 • 8 mmHg) than CON -D (ill • 5, p <0.01).

1,25 DHCC reduced MAP in UR +D (118 • 6. p<0.05) when compared with UR -D.

MAP in UR +D was not different than CON -D.

Parenteral 1,25 DHCC corrected both the insulin resistance and hypertension in uremic rats but had no effect on insulin sensitivity or blood pressure in control rats. To test the efficacy and toxicity we reviewed our experience with recombinant GH (pretropin) administration to pediatric renal transplant (tx) recipients. Criteria forprotropin therapy: 1) children whose height (ht) > 2standarddeviations (SD) below the mean for age 2) either su-bnorma] GH level (<I0 ng/ml) or zero growth velocity over the preceding year. GH levels were analyzed at 20 minute intervals over a 2 hrperiodafter stimulation with L-dopa and/or clonidine. Ht was normalized using SD score (z score) = (pt ht -mean ht for age and gender) ~ SD of ht for age and gender. Catch up growth (CUG) was defined as inincrease in z score (~z) > 0.4. The growth velocity index (GVI) = pt GV § normal GV fo-r age and gender x 100. GH stimulation test was performed on 30 pts. Subnormal levels were observed in 67% of pts. 20 pts (17 with subnormal and 3 with normal GH levels but zero GV) consented to GH therapy (0.i mg/ kg, subcutaneously 6 days/week). 17 (14 tx) pts have completed 1 yr of GH and are the subjects of this analysis. All 17 pts were receiving cyclosporin and 12 were receiving pred (5-20 mg/day) during GH therapy. 6 of the 17 pts (35%) demonstrated CUG (az range +0.4 to +2.1). Their mean age (12.8 vs 11.6 yrs) and serumcreatinine (1.43 vs 1.47 mg/dl)were similar to those without CUG. Of note, pts not receiving pred (n:5) all demonstrated CUG compared with 1/12 pts on pred (p<.O01). Despite no improvement in mean z score before and after GH in pred group (az = -.06), there was an increase in theGVl (18 vs 84, p<.O01). The mean serum creatine (n=17) rose afterGH from 1.46 to 1.59 mg/dl, p<.O01.

Conclusfon: I) Despite GH administration, catch up growth does not occur post transplantation in growth retarded children on maintenance prednisone therapy. 2) However, the improvement in GVI in prednisone treated pts may suggest the need for an fncreaseindosingofGH. 3) A placebo controlled trial isnecessarytoinvestigatetherelationship if any, betweenGHadministration and worsening renal function. CMA is well recognized as enhancing bone resorption (BR), but its effect on BFR, and the factors affecting bone changes remain to be described. The aim of the present study was to evaluate the effects of CMA on bone turnover in growing uremic and normal rats, and thc possible role of some hormonal changes.

Four groups of 15 rats fed a 30% protein diet were compared. Two had moderate uremia (excision of 70% renal mass) : one had CMA (UA rats) which was corrected by adding NaHCO3 in the diet of non acidotic (UNA) rats, without changing dietary Na. Of the two sham-operated groups, one was normal (SNA), one was rendered acidotic by C1NH4 in the drinking water (SA rats). All rats were pair-fed and had similar growth. Diets were given from days 7-21. IGF1 was measured by RIA slier plasma extraction, and PTH with 1-34 antibody. Pefiosteal BFR (double tetracycline labelling at clays 7 and 191, endosteal BR (surface not covered by labelling), and ostcoid seam thickness (OST) were measured on tibia diaphysis.

UA We have studied the effect of IgA immune complexes (human semm IgA-(F ab')2 goat anti human IgA) on the production of complement proteins C3, factor B and C2 in macrophages, using biosynthetic labelling, immuneprecipitation, SDS-PAGE and autoradiography. There was a consistent increase in C3 production and secretion without any change in C2 or factor B biosynthesis. This'increase appeared after a 24 hour incubation period of the macrophages in the presence of IgA immune complexes. IgA immune complexes also induced a concomitant increase in TNF production (310 q: 24u/ml/5x105 cells vs. 12 :t: 8u/ml/5xl05 cells in the control). The presence of prednisolone (2xl0"5M) or dexamethasone (lxl0"7M) inhibited the IgA immune complex induced TNF production, but had no effect on C3 increased synthesis, suggesting that the effect of IgA immune complexes on complement, was not mediated by endogenous TNF production. These findings may be relevant to the local inflarmnatory response in IgA nephropathy. Maintenance of brain cell size during osmolal stress is a vital biological function and accumulation of electrolytes and compatible organic osmolytes within the cerebral cytosol is essential for this adaptation. We conducted the following studies to determine the qualitative and quantitative aspects of the cerebral cell volume regulation to hypernatremia (H) in developing rats. Male rats were studied at ages 12, 18 and 20 days. Adult animals were also examined. H was produced for 48 h by daily injections of i N NaCI, l-2ml/100 g BW/dose, designed to achieve a serum Na + concentration~ 175 mmol/L. Sham injected littermate animals were used as normonatremic controls. At the end of the study, the brain was excised. One half was dried at 70 ~ to determine water content and then dissolved in 5 N HNO 3 for electrolyte analysis. The other half was homogenized in 6% perchloric acid for HPLC determination of taurine, glutamine, inositol and creatinine content. Brain ~;ater declined steadily during development from 85% to 79.8%. This change correlated with a fall in cerebral taurine and total electrolyte content as the rats matured. In the face of equivalent levels of H, the percent loss of brain water was comparable at all ages studied. The increment in brain electrolyte and total organic osmolyte content, expressed as a percent above basal levels, was similar in the four groups studied. We conclude that immature rats have a fully developed capacity to regulate cerebral cell volume during H and de not lack any of the transport processes required for full expression of this adaptation. The brain of the developing rat acts as if it is designed to protect a higher "set point" for brain cell size. If cell volume regulation is a truly primitive system, this would be another example of ontogeny following phylogeny. (NDI) is an xlinked inherited disorder characterized by renal resistance to the action of the antidiuretlc hormone arginine vasopressin (AVP). A Siblrian husky dog family is described that phenotypieally resembles human NDI. Three male dogs from a litter of Husky dogs presented with severe polyuria, polydipsia and low urine osmolallty. Hypertonic saline infusion raised plasma osmolality and plasma AVP indicating normal osmotic AVP release. A dehydration test and exogenous application of pharmacological doses of AVP and the long lasting AVP analogue desmopressln (DDAVP) demonstrated a deficient renal antldiuretic hormone response. Kidney membranes prepared from NDI-affeeted male huskies were examined for vasopressin binding and response. Compared to membranes from unaffected canines, those from the kidney inner medulla of NDi-dogs possessed normal V2-reeeptor numbers but a 10-fold lower affinity for [Arg8] vasopressin. Adenylate cyelase stimulation by AVP in contrast to that by forskolin or GTP-analoguee was similarly reduced in a dose responsive manner. The NDI-dogs showed physiological responses to very high doses of V2-specifle agonists, consistent with V2-receptors of a lower affinity. Prolonged treatment with V2-agonists, 1 -deamino [D-ArgS] VP (DDAVP) and 1-deamino [Val4, Sar7] AVP (dVSAVP), rendered the NDI-dogs near normal in terms of water intake and urine osmolality. Thus alteration of the vasopressin V2-receptor in the kidney appears to be the molecular basis of NDI in husky dogs. With very high potent V2-analogues, treatment appears to be possible. Infection with verocytotoxin (VT) producing E.coli is the main cause of the epidemic form of the hemolytic uremic syndrome. The endothelial cell, which plays an important role in the pathogenesis of the hemolytic uremic syndrome, is believed to be a putative target for VT. In vitro studies have demonstrated that endothelial cells become more sensitive to VT when inflammatory mediators are present. The inflammatory mediators TNFu and IL-1 are produced by monocytes and mesangial cells and may play a local role in the kidney.

In this report we demonstrate the influence of inflammatory mediators on the binding of VT to the endothelial cells. Preincubation of human umbilical vein and femoral vein endothelial cells with TNFo for 24 hours results in a ten-to hundred-fold increase of specific binding sites for ~251-verocytotoxin-1 (1261-VT-1). Furthermore, interleukin-1 (IL-1), lymphotoxin and lipopolysaccharide also markedly increase VT-1 binding. An exposure of only 6 hours to TNFo was already enough to enhance the number of VT-1 binding sites on the endothelial cells for at least 2 days. In order to demonstrate that the increase in VT binding was due to an increase in the functional VT receptor, glycolipid extracts of TNFmtreated cells were analysed by thin layer chromotography. An increase of globotriaosylceramide (GbOse3cer) was observed, suggesting that preincubation of human endothelial cells with TNFo leads to increase in GbOse3cer synthesis in these cells.

We conclude from this study that TNFu and IL-1 induce one (or more) enzyme(s) that is (are) rate-limiting in the synthesis of the glycolipid VT-1 receptor, GbOseacer. These in vitro studies suggest that in addition to verocytotoxin-1, inflammatory mediators play an important role in the pathogenesis of the hemolytic uremic syndrome. DA-1 receptors are involved in the regulation of sodium transport in the renal proximal convoluted tubule (PCT) as well as the distal nephron. We have characterized DA-1 receptors in the PCT and cortical collecting duct of rats. Furthermore, we have reported a DA-1 receptor -Adenylate cyclase (AC) coupling defect in the PCT of the Spontaneously Hypertensive rat (SHR) which was not found in any other nephron segment. The DA-1 receptor coupling defect was also found in the 3 wk old SHR but not in age matched Wistar-Kyoto rat (WKY). The purpose of this study is to determine if the defective DA-1/AC coupling described irrproximal tubules of SHR is also present in the PCT of new hypertensive rat strains.

WKY and SHR were crossbred yielding two new strains that separated the hyperactive phenotype (WK-HA) from the hypertensive phenotype (WK-HT). We compared pharmacological profile of DA-1 receptors and linkage to AC activity in the PCT of WK-HA and WK-HA.

Basal AC activity was similar in WK-HA and WK-HT (35.6 _+ 5.6; n = 3, 43.5 _+ 4.9 f mol/3mm PCT/20 rain; n = 4, respectively). The DA-1 agonist, fenoldopam (10-7 M), stimulated AC activity in WK-HA (70.6 _+ 16.1, n = 3) but not in the WK-HT (43.3 + 5.3 fmol/3mm PCT/20 min, n = 4). Gpp(NH)p (10-5M), nonhydrolyzable GTP analogue, stimulated AC activity to a similar extent in WK-HA PCT (84.9 ~: 15.9, n = 3) and WK-HT PCT (84.4 _+ 8.5 fmol/3mm PCT/20 rain, n = 4). Forskolin (10-5 M) also stimulated AC activity in both strains of rat PCT. Specific binding of ]25I-Sch 23982 to rat PCT was concentration dependent and saturable in both strains. The Kd and Bma x were similar in WK-HA (23.9 + 1.7 nM, 0.52 _+ 0.04 p mol/mg protein, n = 5) and WK-HT (23.8 + 3.8 riM, 0.58 _+ 0.14 pmol/mg protein, n =5). These data suggest the presence of a coupling defect between the DA-1 receptor and AC in the PCT of WK-HT as well as PCT of SHR. Several renal tubular dysfunctions have been described in IDDM which are thought to be characteristic findings for the renal manifestation of the disease. In order to evaluate disturbances of renal potassium handling during the course of IDDM, serial measurements of urinary characteristics of potassium and sodium handling as well as those of plasma concentrations of aldosterone (Aldo), atrial natriuretic peptide (ANP), plasma renin activity (PRA) and urinary excretions of catecholamines were carried out in three groups of diabetic children (Group h newly diagnosed patients < 6 month, n = 8; Group Ih patients having diabetes > 5 years; n = 1 8; Group Ill: diabetic children in ketoacidosis (DKA) n = 9). Data were expressed as mean + SE and compared to those of healthy controls (C) (n = 12). Tra-~stubular potassium gradient (TTKG) was significantly low in each group of diabetics (Group I: 3. It is concluded that TI-KG is also a valuable method for the evaluation of mineralocorticoid action in distal and collecting tubules in pathological condition . Renal potassium handling and aldosterone bioactivity is impared in diabetes mellitus. The low TTKG is a characteristic feature of the renal involvement of diabetes which already persists from the very early course of the disease. Low aldosterone bioactivity may be an early manifestation of tubular dysfunction in diabetes mellitus. Deflazacort (DFZ) is an oxazolone derivative of prednisone, reported to have similar immtmosuppressive effectiveness but less undesirable effects upon electrolyte, mineral and lipid metabolism. In 1990 we started a program of switching our patients (P) with a functioning kidney graft who had not had acute rejections (AR) for at least 6 months (m), from methyl-predvi~one (MP) to DFZ. We report the evaluation of graft function (GF), new rejection episodes, statural growth and blood pressure (BP) control in 22 children from 5 to 18 years old, x 11.4. Comparison was made for each P and for the group between the period on MP and DFZ with a minimum follow-up of 6 m for each medication. Follow-up on DFZ ranged from 6 to 18 m. There were no changes in serum ereatinlne levels (MP 1.15 ___ 0.4 mg/di vs. DFZ 1.17-+0.45 mg/di, x -+ DS p=NS). Only 1 P presented 1 steroid respondent episode of AR 4 m after switching, compared to 3 episodes on 2P, while on MP. 8 children increased growth velocity in at least 1 eentile, 4 showed no changes and 3 decreased at least 1 eenfile. Mean SDS for stature increased + 0.55, due to an increase in 7 P of at least 1 SDS. BP control was evaluated by registering the need for medication at the end of each period. Children on no medication increased from 40% to 80% (P<0.05), while those requiring more than one hypotensive drug decreased from 27% to 0% (p<0.05). There were no significant changes in Cyelosporin A dosage between the 2 periods. There was an obvious decrease in "cushingoid" features in all P (Pictures will be shown). We conclude that: 1-Statural growth, although subject to the influence of several variables, showed a tendency to improve with DFZ, 2-The need for antihyper tensive medication diminighed significantly, and some children could stop taking them. 3-Alongside these apparent benefits, we could not detect any increased risks of rejection crisis nor any deterioration in GF. A longer follow-up is necessary to see if they persist with prolonged use of the drug. Acute saline volume expansion (VE) in the developing animal is associated with a blunted natriuresis when compared to the adult natriuresis. Our previous studies suggested that an attenuated RIHP response in the developing piglet (P) may participate in the blunted natriuresis of VE. The effect of acute saline loading (5%/bw) on RIHP and sodium excretion was examined in adult pigs (A), >70 days and developing piglets (P), 30 days. In response to VE, P excreted significantly less Sodium than A, AUNaV: 1.7 4-0.5 vs 3.8 -t-0.7 /zEq/min/gkw.

The increase in fractional sodium excretion, in response to VE was also significantly less for P than A. Associated with the blunted natriuretic response in P was an attenuated increase in RIHP, 6.1 + 1.1 to 6.1 + 1.6 mmHg in response to VE. In contrast A increased RIHP from 8.8 + t.3 to 12.3 + 1.5 mmHg during VE. When RIHP was prevented from increasing during VE in A, the natriuretic response was significantly attenuated, AxUNaV: 0.93 +_ 0.12 /zEq/min/gkw. To further quantitate RIHP mediation of the blunted natriuresis in P, intrarenal (IR) infusion of the vasodilator acetylcholine (ACH) was used to increase RIHP in P during VE. IR ACH infusion during VE in P corrected the RIHP response from 6.9 + 1.1 to 12.9 + 2.0 mmHg, and restored the P natriuretic response, AUNaV: 4.5 + 1.0 #Eg/min/gkw to A capability. In summary: 1. The developing piglet (P) exhibits a blunted natriuresis of VE when compared to the adult pig (A). 2. Associated with the blunted natriuresis in P is an attenuated RIHP response to VE. 3. Correction of the attenuated RIHP increase in P by IR ACH during VE restores the natriuretic response of P to adult capability. Conclusions: The attenuated RIHP increase during VE mediates, in part, the diminished natriuresis of VE in P. To investigate the impact of pre-Tx patient status, allograft condition and postoperative management during the first three months on eady and late transplant function, we evaluated 44 successful renal Tx performed in our unit between 1984 and 1991. The long-term immunosuppressive regimen usually consisted of triple therapy. Early graft function was defined by the duration of dialysis treatment required post-Tx. Later function was determined by a single-injection inulin clearance obtained 3.2 _+ 2.2 years post-Tx. A total of 27 clinical, immunological and pharmacological variables were evaluated, and correlated with early and late graft function by stepwise multiple regression analysis. The main independent predictors of poor eady renal function were the percentage of antibodies against a selected cell panel before Tx (p < 0.0001) and the cold ischemia time of the graft (p < 0.02). In addition, pre-Tx treatment with erythropoietin (EPO) was associated with prolonged post-Tx dialysis (p < 0.10), and the pre-Tx hematocrit was positively correlated with the duration of post-Tx anuria (p < 0.05). The best single predictor of late function was the time since "Ix (p < 0.0005), a long "Ix period being associated with poor GFR. Independent of the time since Tx, the integrated average cyclosporin A dosage during the first three post-Tx months contributed positively (p < 0.05) and the mean blood pressure negatively (p < 0.12) to the prediction model. Pre-Tx treatment with recombinant growth hormone (GH) had a slight positive impact on GFR (p < 0.13). In contrast, the duration of post-Tx anuria or dialysis, the number of rejection crises or treatment with Ca-channel blockers had no significant effect on later GFR. Finally, we identified treatment with ACE inhibitors and blood pressure at the time of the clearance study as negative and Ca-channel blocker treatment and cyclosporin A dosage as positive predictors of GFR (all p < 0.05). We conclude that the existence of cytotoxic antibodies and ischemia time are the main predictors of early graft function. Pre-Tx EPO treatment may aggravate initial graft dysfunction by increasing blood viscosity. Late graft function is mainly determined by the time since "Ix, adequate cyclosporin A dosage and good blood pressure control appear essential for long-term graft function. Pre-Tx GH treatment has no deleterious effect on late graft function. After uNx in childhood the remaining kidney has to function during a complete lifetime. Rat studies indicate that it may take 50% of the lifetime before changes in GFR occur. Human studies usually report a shorter follow-up. We have investigated cases of uNx below 16y of age and current age over 18y. Longest follow-up was 52y. Plasma inulin clearance (GFR), mean arterial pressure (MAP), and albumin excretion (U~V) were measured. In iii cases, with no recorded damage of the remaining kidney, GFR (mean• was 86• ml/min.l.73m 2, i.e. about 70% of normal two-kidney level. Multiple regression analysis showed collinearity between current age and time post-uNx. Gender and age at uNx had no significant correlation with current GFR. Under 30y of age (n=60) mean GFR was stable (90• ml/min.l.73m2). In men over 30y (n=22) linear regression analysis indicated a fall in GFR and a rise in MAP and Ua~bV. In women no significant correlations were found. A second group consisted of 34 cases with recorded abnormalities of the remaining kidney. Compared to the group with an intact kidney remaining, a higher incidence of albuminuria and renal insufficiency was observed.

Twelve subjects with an U,~bV >250 mg/day.l.73m 2 had a lower GFR (-39%) and a higher MAP (+14%) compared to those without albuminuria. Renal function parameters of the latter group were similar to those remaining with an intact kidney. In conclusion: good GFR can be maintained for up to 50 years after uNx in childhood. The fall in GFR and the rise in MAP and UalbV in males over 30y, appears faster than reported for maleswith two kidneys. When an abnormal kidney remains there is an increased risk to develop albuminuria and renal insufficiency. The clinical outcome of VUR treated conservatively in infants and young children has hot been reported from any long-term prospective study. We enrolled 113 normotensive subjects (92F,21M) 1 mo-5 years old (62% <2 years) with grade I-I/I/V primary VUR in at least 1 ureter and without renal scarfing or dysfunctional micturition for a 5 year follow-up study. VUR was unilateral in 65 (58%;27R,38L) and bilateral in 48(42%). Of the 226 renal units, VUR was grade IV ih 4, III in 51, II in 81 I in 25 and 0 in 65. Treatment included antibiotic prophylaxis and surveillence for bacteriuria, annual VCUG until VUR resolved (no VURx2years), IVP at 1,3,5 years to assess renal growth (planimetric surface area) and scarring, and annual screening for renal injury and hypertension. To date, 64 patients have completed 5 year follow-up evaluations. Breakthrough UTI and asymptomatic bacteriuria, all treated promptly, occurred in 21(34%) patients. Of 38 ureters with no VUR at diagnosis, 10(26%) were noted to have grade I-II VUR subsequently which persisted in 3 ureters at 5 years. Of the 88 ureters with VUR at diagnosis, 49% resolved and 11% were either unchanged or worse at 5 years. VUR resolved more often when VUR was grade I(82%) than grade 11(73%) or [I1(45%); no age-related difference was observed. Resolution was better also when VUR was unilateral left (72%) than unilateral right(46%) or bilateral(58%). GFR remained normal in all patients. Blood pressure was elevated in only 1 patient. Renal growth was impaired (>-2SD) in 20 kidneys of which 9 were scarred but unrelated to the grade of VUR. Scars were identified in 11 kidneys of which 5 had breakthrough infection, 4 after scarfing was noted. Cortical thinning (>-2.5SD) without calyceal deformity was seen in 6 other kidneys. The incidence of scarring in grade I VUR was 9%, II was 11% and HI was 27%. We conclude that renal injury is more likely with dilating VUR but can be associated even with mild VUR in infants and young children treated medically. GH induced carbohydrate intolerance has not been a problem in management of GH deficient children (GHD), these children have low insulin levels to begin with. Chronic GH hypersecretion as occurs in acromegalic adults is frequently associated with hyperinsulinemia and carbohydrate intolerance. Likewise non GHD subjects such as children on RRT (CRRT) treated with superphysiological doses for years may be exposed to the same risk. Mean final height of patients with nephropathic cystinosis is below 140 cm in females and below 145 cm in males. Cysteamine treatment is not able to induce catch-up growth if height has fallen below -2 SD. To improve growth in patients with a height below -2 SD, a multicenter study for treatment with recombinant human growth hormone (rhGH) (I IU/kg/week) was started. 74 patients are recorded, 19 will finish the first treatment year in 1992, 6 have already finished the first year and 3 the second year.

So far (n=6), height velocity increased from median 1.3 (0.6-6.0) cm per year at basal to 7.0 (4-11.5) cm during the first year of therapy. The loss of GFR measured by CIN and CCR under rhGH was not higher than before rhGH therapy, and proteinuria as well as urinary calcium excretion did not increase. Chloroquine is an antimalarial and antirheumatic lysosomotropic drug which inhibits taurine uptake into and increases efflux from cultured human lymphoblastoid ceils (Tallan, Fed Proc 43:1779 ,1984 . It inhibits taurine uptake by rat lung slices (Lewis, Biochem Phaxmacol 39 (3): 431, 1990 ) and affects the uptake and release of cystlne from cystinotic fibroblasts (States, Metabolism 32 (3): 272, 1983) . Speculations on its mode of action include a proton gradient effect, a non-specific alteration in membrane integrity, and membrane stabilization. In this study, the effect of ehloroquine on the uptake of several amino acids by rat renal brush border membrane vesicles (BBMV) was examined. BBMV were prepared from male Sprague-Dawley rats by a method of magnesium precipitation and centrifugation, and incubated in the presence 100mM NaC1, radiolabelled amino acid, and varying concentrations of chloroquine. The effect of chloroquine on taurine efflux and binding was also examined. Chloroquine significantly inhibited the active, NaCl-dependent component of 10 IxM taurine uptake at all concentrations tested (100, 250, 500, 750 1000 g_M), but did not change equilibrium values. Analysis of these data indicate that the inhibition was competitive. It did not affect tattrine efflux or non-specific binding to lysed membranes, nor did it affect the NaCl-independent diffusional component of taurine transport. Chloroquine (1 raM) inhibited the initial rate uptake of the imino acids L-proline and glycine, and the dibasic amino acid L-lysine. It inhibited the uptake of D-glucose, but not the neutral a-amino acids Lalanine or L-methionine. Uptake of the decarboxylic amino acids, Lglutamic acid and L-aspartic acid, was significantly enhanced. With regard to amino acid uptake by BBMV, these finding do not support the currently proposed mechanisms of the action of chloroquine and further studies are indicated to determine why it affects the initial rate of active amino acid transport and serves as a probe of amino acid transport. Thirty-nine concurrent inulin clearance (Cin) and creatinine clearance (Ccr) studies were conducted on 31 pediatric patients in whom Cin ranged from 2.8 to 135.8 ml/min/l.73 m 2. Although there was good correlation between Ccr and Cin (r = .96), the Ccr consistently over estimated Cin and the 95% confidence interval for prediction of Cin from Ccr was large. The ratio of the Ccr/Cin was 1.36 + .22 for the entire group and 1.50 + .25 for the 17 studies with Cin <40 ml/min/l.73 m2.

-It is common practice to calculate GFR from the equation GFR = k-L/Pcr where k is a proportionality constant and L is height. The measured Ccr was 16.7 + 10.3 ml/min/l.73 m2 greater than the Cin (P <.001) and The calc-Ccr, using Schwartz' values for k, overestimated Cin by a mean of 31.6 + 20.8 ml/min/l.73 m 2 (P<O.O01). The pToportionality constants, k, for estimation of GFR from Pcr and L were calculated from our data with both Ciu and Ccr for GFR using the equation: k = GFR.Pcr/L ( The data from a 20 year old girl with refTux nephropathy was omitted from this analysis as an outlier (kin = .55, kcr = 1.00). Since Cin is the accepted standard for GFR, the proportionality factor used for calculation of GFR from Pcr and L should be derived using Cin in the equation k = GFR.Pcr/L, not Ccr. Xanthines are widely used inmanagementofapnea ofprematurity, BPD, orto assist weaning from mechanical ventilation. There are few and conflicting reports of renal side effects of this therapy. Nineteen neonates, mean gestational age 31.1 + 2.8 wks and mean birthweight 1481 :f_.454 gm, were studied before and after a 20-minute loading infusion of 6 mg/Kg aminophylline (Am), at mean age of 4.5 +4.0 days, continued 12 hrs later by maintenance doses of 2 mg/Kg every 12 hrs. Consecutive serum and urine samples were collected before and immediately after the loading dose, 24 hrs after, and 5 days after while on maintenance dose. Water and electrolyte balance and renal function were studied, and are presented in the There was a marked effect immediately following Am load with maximum effect at 2-4 hrs. Most of the effects were no longer evident after 24 hrs despite continuing Am maintenance and there was no change in GFR or serum NA and K throughout the study. Thus in premature infants, Am loading dose, but not the maintenance dose, has an effect on tubular reabsoIption causing diuresis, natriuresis, kaluresis, calciuresis and uricosuria. Although estimation of glomerular filtration rate (GFR} is the most commonly used parameter of kidney function, obtaining an accurate measure of GFR is difficult and often frustrating. The inaccuracy in estimation of GFR using standard clearance procedures is commonly due to the difficulty in obtaining accurately timed, complete urine collections.

Infusion clearances have been recommended in order to circumvent this problem. In theory, within the limits of experimental error, the INF-Cin should be identical with the R-Cin. We have carried out 40 studies on 32 cooperative subjects during which data for R-Cin (using voided urine collections) and lNF-Cinwere obtained (Table) . Measurement of inulin clearance suffers from the need of a constant intravenous infusion, In the present study, we used a non radioisotopic contrast agent, amidotrizoate meglumine 65 %, to measure GFR after a single subcutaneou s injection. Inulin and creatinine clearances were measured simultaneously. Sixty two measurements were performed in 50 patients (29 boys, 21 girls, mean age 11.6 yrs, 3.5 to 19.4), of whom 21 were diabetic, 18 had chronic renal insufficiency (CRI) and 11 had a kidney graft. The dose of meglumine was 650 mg/1.73 m 2. Initial dose of inulin was 50 mg/kg , followed by a constant rate infusion calculated to maintain the plasma concentration at 20 -30 mg/dl. After a 60 min equilibration period, blood and urine samples were collected at the beginning and end of 4 periods of 30 min. Creatinine was measured by Jaffe kinetic method, inuline by a colorlmetric method and meglumine by HPLC. Our results indicate that meglumine clearance allows a more accurate approach of GFR than creatinine clearance. However it cannot stand for inulin as a "true marker" of GFR. In clinical practice, variation in newborn renal function in response to a given insult may be in part due to different magnitude of production of endogenous substances (e.g., endothelin, renin). The effect of endothelin on renal function during development is not well known. We correlated RBF (ml/min) blood pressure (MBP, mmHg) and other renal function changes with serum ET-I level in 20 7-10d piglets.

30mn ET-I infusion (Grl 25P~/kg/mn or Gr2 50 ~g/kg/mn; Gr3 i00 ~g/Kg/mn; or Gr4 none) was followed by 60 mn recovery (R). RBF (ml/mn) (transonic doppler) BP, GFR (ml/mn), FENa, UV were measured; renal vascular resistance (RVR=RBF/MBP, ml/mmHg/mn), and serum ET-I levels (pmol/L by RIA method) were measured every 15mn.

In Grl and Gr4, BP, REF, GFR, FENa did not change significantly. There was a significant increase in BP, RVR, and decrease in GFR, UV and FENs in Gr2 and Gr3.

In Gr3 RVR and GFR recovered fully by 60 min; FENa and UV recovered only up to 75% of baseline.

RVR, RBF and GFR correlated with ET-I levels (r= <-.057 to -0. 6 ET-I induced renal function and hemodynamic changes are dose-and serum-level dependent.

High serum level of ET-I has main effect on BP, RBF, RVR and GFR and not on tubules. Ceftazidime (CAZ) is a third generation cephalosporin with a broad spectrum against neonatal pathogens. It is predominantly excreted by glomeruler filtration.

GFR increases with gestatienaf age as well as with postnatal age, We hypothesiaed that this would also have great impact on the pharmacokJneties of CAZ in the tiny infant and therefore performed a study Jn this patient group. Twenty five neonates (gestattonal age 28 6/7 • 2.0 weeks, birth weight 1250 • 3OOgr) were studied on day 3 and day 10 after birth, GFD was calculated using the continuous inulin infusion technique. Inulin was measured by enzymatic method. The patients with suspected septieaemia, received twice daily 25 mg/kg ceftazidime in a bolus injection, CAZ cnncentrations were measured postnatally repeatedly from 0 to L2 hours after infection, They were quantltated by HPLC. Results are shown in table I. . totaJbodyclearanc, e; Yd~ = vc4gmeofdistributioo.

The data indicate that pharmacokinetic parameters of CAZ in prete~m infants are directly related to the development nf GFR and chartres in GFR. GFR increases atRnllicantly between day 3 and day 10 as it increases with advancinR gestational are. We sugNest, based on this pharmacokinetic study, that the dosaRe of CAZ tn preterm Inlants in the first days of ]ire may be adjusted to 25 mg/kg once daily. In a large scale study on Ceftazidime pharmaeokineties glomerular filtration rate (GFR) was measured on day 3 and day 10 after birth in preterm neonates. 24 patients were antenatally exposed to DEXA with a mean doae of 24 mg. DEXA is known to stimulate pulmonary development. The effect of antenatal DEXA on the renal function is unknown. We compared the GFR of DEXA exposed children with the GFR in 94 children without intrauterine therapy and with the GFR in 47 children with intrauterine exposure to Indomethaein (INDO, mean dose 200 mg). GFR was measured using the continuous inulin infusion technique by enzymatic method. Influence of gestational age, antenatal exposure to INDO and DEXA was calculated by multiple regression analysis. p < 0.001 9 exposed versus not exposed On day 3 a significant increase in GFR was present (table 1) in the DEXA group compared to the 2 control groups. On day 10 differences could not be detected anymore. The high level of GFR in the DEXA group on day 3 after birth may be related to a direct vasodilating effect on the kidney or to enhancement of renal tubular sodium reabsorption. In low birth-weight (LBW) infants, creatinine clearance has been claimed to underestimate g!omemlar filtration rate (GFR). In order to better define the handling of creatinine by the immature kidney, clearance studies v~ere performed in newborn rabbits, an animal model whose nephrogenesis corresponds to that of premature infants. Results observed in newborn animals were compared to those obtained in adult rabbits. The animals were anesthetized with pentobarbital, mechanically-ventilated and infused with inulin (adult rabbits) or inulin and creatinine (newborn rabbits). Clearances were measured by standard techniques, and expressed in ml/kg per min.

Group 1: In adult rabbits (n=8) with a mean endogenous creatinine concentration of 84_+10 gmolB, creatinine clearance (3.4_+0.7) significantly (p<0.01) overestimated inulin clearance (2.8_+0.5) . Inulin being exclusively eliminated by glomerular filtration, the clearance of creatinine indicates a 23.6+2.7% fractional secretion rate of creatinine. Group2: Newborn rabbits (n=9) were infused with exogenous creatinine so as to obtain plasma creatinine concentrations in the same range as those observed in adult rabbits (74_+2 gmol/1). In these animals, creatinine clearance (1.13• significantly (p<0.01) underestimated the corresponding inulin clearance (1.34-+0.14), indicating a 12.6_+3.7% fractional reabsorption rate of creatinine. Group 3: In order to increase the creatinine filtered load and consequently decrease the relative contribution of creatinine reabsorption to its final clearance, newborn rabbits (n=l 1) were infused With exogenous creatinine so as to obtain plasma creatinine concentxations of 155• gmolB. In these animals, mean creatinine clearance (1.33_+0.56) did not differ significantly from inulin clearance (1.39~0.53). Conclusion: In the mature rabbit, creatinine clearance overestimates inulin clearance, indicating significant tubular secretion of this endogenous marker. In the immature animal, creatinine is significantly reabsorbed, resulting in creatinine clearance values that underestimate true GFR. These experiments confirm that creatinine clearances measured in LBW infants should be interpreted with caution. The role of the vasodilator mechanism endothelium derived relaxing factor (EDRF/NO) in the renal hemodynamic (RI-I) maturation of the developing animal is not known. We examined the participation of EDRF/NO in 2 experiments.

In the first experiment in developing piglets (P) 21 days, n=9 and Adult pigs (A) >70 days, n=6, following control collection, C, intrarenal fiR) infusion of EDRF/NO competitive inhibitor N-nitro-L-arginine methylester (L-NAME) 50 /xg/kg/min continued through experimental collection, E. During C, P exhibited significantly lower RBF and higher RVR than A. Both groups responded significantly from C to E; RBF decreased in P from 1.10 _ 0.1 to 0.61 _ 0.1 ml/min/gkw and in A from 2.27 _ 0.2 to 1.62 _ 0.2 ml/min/gkw. RVR increased in P from 4.03 +__ 0.4 to 9.31 _ 1.5 mmHg/ml/min and in A from 1.05 _ 0.1 to 1.65 _ 0.1 mmHg/ml/min. P demonstrated significantly greater percent changes in RBF: P 45.6 +_ 4.2% VS A 28.9 _ 3.1% and RVR: P 128.2 _ 21.3% VS A 57.2 _ 7.5%. In the second experiment, meclofenemate pretreated P, n=4, received IR acetylcholine (ACH) .05 /~q/kg/min an EDRF/NO mediated vasodilator, followed by IR ACH + L-NAME. IR ACH produced a 71.0 + 14.6% increase in RBF which was completely abolished with IR ACH + L-NAME. Summary: EDRF/NO inhibition with L-NAME, 1. Significantly decreases RBF and increases RVR in both P and A. 2. Produces a greater RH response in P than A. 3. Abolishes ACH mediated increases in RBF in P. Conclusions: EDRF/NO 1. participates in the maintenance of RH in P and A. 2. may have a greater role in RH in P than A. Various renal findings have been associated with nonoliguric hyperkalemia (HI<) in the extremely low birthweight infant (ELBW). The purpose of this study was to re-examine the possible renal/fluid etiologies of HI< along with trauscellular flux of K + as it relates to Na +, K+-ATPase activity. 39 ELBW infants had 24 hr urine collections performed for the first 3 days of life with simultaneously measured intakes.

(BW+_SD = 813+129 ~n GA+26.5jl.3 wk for all; p = NS for BW and GA for HKvsNK).

No~-hemolyzed blood was obtained daily for cellular Na + and K + levels by means of RBC lysis. The resultant RBC membranes were analyzed for Na +, K+-ATPase activity.

The results indicate that intracellular K + levels decreased significantly over the 3 days (p=.02 ANOVA) in the HK group. In association with this, was a concurrent decrease in Na +, K+-ATPase activity.

The renal/electrolyte data show no differences in flow rates, output/input ratio, Na + excretion, FeNa values or Na + balance between the groups. BUM, sCr, BUN/Crwere significantly higher and Ccrwas lower in the HK group for D2 and D3. Potassit~n excretion (Kexc) and balance (Kbal We tested the hypothesis that the rise in plasma All levels following birth modulates the desensitization of reflex control of renal sympathetic nerve activity (RSNA) and heart rate (liP,) shown, to occur after birth.

Reflex changes in RSNA and HR were studied during bolus infusion of phenylephrine (PHE) and nitroprusside in conscious F (n=4, 135-140 days gestation) and NB (n~5, 4-7 days of age) sheep before (control) and after angiotensin converting enzyme inhibition (ACE-I) using enalaprilat (0.2 mg/kg Indomethacin (ID) or other non-steroidal anti-inflammatory agents (NSAIS) administered in large doses early on in pregnancy for prolonged periods may produce a syndrome which includes renal failure with cystic dilatation of developing nephrons, coagulopathy, intestinal perforation and premature closure of the ductus arteriosus.

We report the occurrence of this syndrome in 5 neonates exposed in utero to NSAIS (4 ID, I ibuprofen). Four of the five were one of two twins, monozygotic or dizygotic. ID was initiated in each case prior to 24 weeks gestation for polyhydramnios and was continued until delivery. The dosage ranged from 100-400 mg. daily. Gestational age at birth was 30-34 weeks. One of the 5 neonates died in the neonatal period and the other 4 have chronic renal insufficiency. Renal histology obtained in 3 of the patients (2 biopsies, I autopsy) revealed immature glomeruli with cystic dilatation of superficial nephrons, dilated tubules and interstitial fibrosis.

The twin siblings also seemed to have mild abnormalities. One has abnormal renal echotexture on ultrasound, one developed a coagulopathy in the neonatal period and 2 seemed to be normal.

In conclusion ID or other NSAIS used early in pregnancy and for pro~qqged periods may lead this to recently described syndrome ~'~. A striking feature of this syndrome is the occurrence in one of twins. Renin secretion increases rapidly at birth, but mechanisms controlling this increase are still unknown.

We postulated that an increase in renal sympathetic nerve activity (RSNA) at birth stimulates renin secretion postnatally.

To test this hypothesis, the role of renal nerves in regulating changes in plasma renin activity (PRA) and renal renin gene expression during the transition from fetal to newborn life was studied in intact (n=6) and renally denervated (n=6) fetal sheep before birth and 24 h after delivery.

Renal denervation had no significant effects on PRA in near term fetal sheep.

However, it attenuated the rise in PRA observed in newborn lambs 24 h after delivery.

In lambs with intact kidneys, PRA increased (p<0.05) from 3.26• (pre-delivery) to 6.34• ng AI/ml/h (24 h post-delivery) while in lambs with denervated kidneys, pre-delivery and post-delivery values were 2.84• and 2.49• ng AI/ml/h, respectively.

Renin mRNA levels, determined by densitometric analysis, were lower (p<0.001) in denervated (4.4ii.0x103 DU) than in intact kidneys 24 h after birth (23.5i5.8xi03 DU).

Renal denervation had no effect on ~actin mRNA levels.

These results support the hypothesis that the rise in renin gene expression and PRA at birth are secondary to an increase in RSNA. We have shown that renal nerves play an important role in r~gulating renal blood flow an~ sodium excretion during parturition.

Since changes in renal function mediated by renal nerves are dependent on activation of al-adrenergic receptors, the present study was designed to characterize the effects of renal denervation on ~tb-AR gene expression during the transition from fetal to newborn life.

140-142 day gestation lamb fetuses (term 145 days) were either denervated (nffi6) or sham operated (n=6) and then delivered 72 hours later.

At 24 hours of postnatal age, total kidney RNA was isolated, gel electrophoresed and hybridized with a 32P-radiolabelled 458 bp 5' fragment (generated from a full length ~lb-AR cDNA).

For densitometrie standardization of signal intensity, a 32p-UTP labelled ~-actin probe was prepared.

We have previously shown ~-actin gene' expression to be unaffected by denervation.

The elb-AR mRNA/~-actin mRNA ratio in the denervated lambs (1.33• was significantly greater than that ratio in the innervated lambs (0.92• p=0.0032. ~ere were no significant differences between the two groups in blood pressure, heart rate, and plasma catecholamine levels.

These data demonstrate that renal denervation is associated with an upregulation of alb-AR gene transcription after birth.

These data also suggest that renal sympathetic nerve activity regulates the expression of renal ~Ib-AR gene during the transition from fetal to newborn life. Tubular renal function and sonographic studies were investigated in a group of 34 very low birth weight asymptomatic children when they were older than four (Group VLBW). The results were compared with 14 healthy children (Group C) who were born at term on the same date as each one of 14 children in the VLBW Group.

Results: Birth weight in the VLBW Group was 1310 __+ 243 g., with a gestational age of 30.9 _+ 2.6 weeks. When they were studied, mean age in VLBW Group was 7.4 "4-1.9 vs. 8.1 -'-2.0 years in C Group (ns). We did not find statistical significant differences between both groups in relation to ions, phosphate, uric acid, magnesium or beta2-microglobulin urinary excretion.

Calciaria in VLBW Group was 3.6 --. 1.7 vs, 2.4 -+ 1.6 mg/Kg/Day in C Group (9<0,05) and N-Acetyl-Olucosamln;dase excretion rate 0WAGER) was 2.2 + 1.0 vis 1.3 +-0.6 mU/i00 ml GFR (9<0.01 The fractional tubular reebsorption of RBP is 99.97% end increased excretion is therefore a sensitive marker of tubular dysfunction. It has been used in studies on patients exposed to nephrotoxic drugs or heavy metals. We obtained early morning urine specimens from 149 well children, from the newborn age-group to 16 years. RBP was measured by an ELISA assay using rabbit ant• (Dako Ltd), albumin by a rsdio-inmlunoassay and cr%atinine by a modified Jeffe reaction. The trend is one of a slight decline in RBP excretion in children over I week of age. However, the range of excretion of children in the first week of life is much greater with values up to 2025 ~g/mmol reflecting the relative immaturity of the neonatal kidney.

The geometric mean for the whole group was 18 ~g/mmol which is greeter than previously reported in adult and paedietric studies.

Albumin shows a less marked but similar trend with e fall in excretion with increasing age, most marked in the first weeks of life. We conclude that the age of the paediatric patient should be taken into account when evaluating tubular and glomeruler proteinurie, particularly in the younger age group. To evaluate the ability of stress response, plasma and urinary catecholamine concentrations, urinary electrolytes and acid-base status were measured in IDDM children (Group h newly diagnosed 2-4 weeks, n=7; Group Ih duration 5-7 yr, n =9; Group IIh duration 10-13 yr, n = 12). The data were compared to healthy controls, n = 7, (X -+SD). Physical stress was induced by 2 W/kg/10 rain bycicle ergometer. IDDM children exhibited metabolic acidosis under stress (pH: Group I = 7.24+0.08; Group II = 7.25_+0.05; Group III = 7.19__+0.03 vs C = 7.36 +0.02). Stress induced an increase in the concentration of plasma norepinephrine (PNE) in each group, the most pronounced elevation was seen in Group I (19.36 __+8.8 nmol/I vs C = 8.3 +3.2, p<.02). Baseline PNE level showed a significant decrease with the duration of IDDM. Excretion of urinary NE (U,E) also increased under stress, however, the highest levels were measured in Group III (580 +__209 pmol/min/I.73m 2 vs 290 __+124 in Group I, p < .01 ). Baseline urinary doparnine (Up^) excretions were similar in each group. Stress caused an elevation in UDA only in C (2.05 +__1.8 vs 4.59 __+2.9 pmol/min/I.73m2). The ratio of baseline UNE/UDA was similar in Groups I, II and C, but higher in Group III. Stress induced a shift towards NE excretion only in diabetic children which was most pronounced in children having IDDM more than 10 years. Stress did not affect urine output in Groups I. and I1., but a decrease was observed in Group III (1.1 +__0.3 vs 0.7 _+0.3 ml/min/1.73m 2, p<.007). Urinary sodium excretion also decreased in Group III after physical loading (130 +47 vs 66 -+33 umol/min/1.73m2). Our data show, that physical stress induces a severe lactic acidosis in IDDM.in spite of the decreased systemic sympathetic activity, the renal catecholarnine response showed a shift towards vasoconstriction, sodium and fluid retention under physical stress in IDDM. These changes correlate with the duration of the underlying disease. Study design. Plasma and urinary electrolytes were determined after an overnight fast in 13 patients with Citelman's syndrome (age 10-20 years), 21 family members of patients (7 siblings~age 10-23 years;14 parents, age 30-52 years) and 13 healthy controls (aged 16-20 years). As urinary calcium excretion may be appreciably affected by sodium, it was also corrected for the sodium factor and expressed both as calcium to ereatinine ratio and as molar calcium to sodium ratio. Conclusions. The urinary calcium to creatinine ratio was reduced 0ot 0nly in patieets with Citelman's syndromebut also in a group of siblings and parents with normal plasma biochemical variables. Urinary calcium excretion discriminated patients and family members from controls more clearly after a slmpie correction for sodium excretion (urinary calcium to sodium ratio). The features of Bartter syndrome in the neonate include not only hypokalaemia, alkalosis and hyperreninaemia, but also severe polyuria, hypercalciuria, nephrocalcinosis and growth retardation.

The 15rostw synthetase inhibitor, indomethacin, partially corrects most of these abnormalities. Indomethacin has also recently been used as an alternative to betasympathomimetics for tocolysis in premature labour and while there appears to have been no increase in fetal mortality, there have been reports of side effects including reduction of fetal urine output, transient post-natar renal insufficiency and oligohydramnios. In addition, indomethacin has also recently been used in the treatment of polyhydramnios.

We wish to report a case of extreme polyhydramnios during early pregnancy in a 34 year old woman whose first child was known to have Bartter syndrome.

Because obstetric opinion indicated that there was a high risk of premature labour with delivery of an extremely low birth weight infant, the mother was treated with indomethacin 200rag/day commencing at 27 weeks gestation. The polyhydramnios decreased and only worsened again when indomethacin was ceased 10 days before delivery.

The post-natal course was marked by transient renal failure (creatinine 0.21 mmol/I) and subsequently, by the development of characteristic features of Bartter syndrome. We believe this is the first occasion that indomethacin has been used to treat poryhydramnios due to fetal Bartter syndrome. Its effectiveness in this case is further evidence that indomethacin reduces polyhydramnios by causing a reduction in fetal urine output. The aims of this study were to establish normal sCr values for the first 4 days of life in healthy newborns in our institution, to compare two different methods of measuring sCr and to assess the interference from B on these measurement. Forty eight healthy newborns with transient hyperbilirrubinemia were enrolled in the study. Gestational age ranged from 37 to 42 weeks. No medication was given to them. Blood was obtained at day 1 (n=8), day 2 (n=26), clay 3 (n=11) and day 4 (n-3). sCr was determined in the same blood sample before and after protein precipitation by trichloroacetic acid to exclude B, using the Jaffe Cobas Mira, Roche automated colorimetric method (n=48) and the enzymatic PAP creatinine, Boehringer method (n=22). The interassay coefficient of variation for the Jaffe method was 3.1% with B and 3.8% without B. 

We recently evaluated two brothers with polyuria and polydipsia. Both of them were known to have this syndrome since the age of 3 years. The older brother. 23 y., underwent full evaluation following recovery from acute dehydration with severe hypernatremia. The diagnosis of nephrogenie diabetes insipidus was proved by lack of increase in urine osmolality above ll2mos/kg H20 in response to 14h. water deprivation and both nasal and intravenous l-dessraino (8-Darginine) vaso-pressin (d DVAP) stimulation tests. Antidiuretic hormone (ADH) secretion reached 12.7 Pg/ml after 14h. water deprivation while plasma osmolality was 328 mos/kg H20 which was referred as a maximal response. We ruled out nephrotoxic agents as a possible contribution to this abnormality. The younger brother, 4 y., was taught by his older one "to drink a lot". Stimulation tests revealed a "partial" response: an. elevation of urine osmolality from basal value of 56 mos/kg H 0 to 232 mos/kg H~0 after water deprivation and to 4~4 mos/kg H20 90 min. after nasal d DVAP adminb3tration. ADH secretion was maximal (11.8 Pg/m while plae:,a osmolality was 306 mos/kg H20 after 7h. of water deprivation. The younger brother was diagnosed, therefore, as a compulsive water drinker. The older brother began a treatment by Kaluril (Hydrochlorothiazide 50m 5 and Amiloride 5 mg) and Indomethaein 75mg, daily. After a period] of 2 months, the diuresis decreased from 9,000-10,000 ml/day to 3,000-4,000 ml/day and, his desire to drink regressed. The younger brother began a training for gradual change in his water drinking habits. In a period of 2 months, both polydipsia and polyuria were significantly decreased. We described one patient with a congenital tubular defect and his brother with a habitual non-familial, not genetically associated disturbance, both presented with polyuria polydipsia syndrome. CsA has a beneficial immunosuppressive effect on the expression of autoimmune interstitial nephritis, but also displays the potential to cause irreversibile interstitial damage by stimulating fibrogenesis. We aimed to explore the possibility that CsA may also exert beneficial "immunosuppressive" effects on tubular epithelial ceils, by altering transcription of genes important for T cell-epithelial cell interactions. We used the reverse transcription-polymerase chain reaction with 32PdCTP to quantitate ICAM-1 expression in proximal tubular epithelial ceils (MCT) exposed to CsA. GAPDH, a housekeeping enzyme, was used to standardize the quantification. We found that ICAM-1 expression in MCT cells, pre-treated with TNFa, is 50% inhibited with 1-5 ug/ml CsA compared to cells treated with vehicle (DMSO) alone. This was confirmed by a northern blot analysis and correlated with inhibition of cell surface ICAM-1 expression determined by immunofluorescence studies. We next examined the effect of CsA on M52.28, a CD8 + cytotoxic and DTH-reactive T cell clone specific for 3M-1 antigen expressed by MCT cells. We found that coincubation of M52.28 with CsA (10-100 ng/ml) had a dose-dependent inhibitory effect on LFA-I. FACS analysis was confirmatory of the results. Similar effects were seen in TNFct, ?IFN, IL-2, and IL-6 transcripts but no change in ICAM-1 expression. Since TNFot and ?IFN upregulate ICAM-1 expression on MCT cells, our studies provide evidence that CsA may in part be immunosuppressive through both direct and indirect modulation of LFA-1 (T cells) and ICAM-1 (MCT) expression. Endothelin (Et) is produced in vitro by normal kidney cells.,Recently, it has been described as autocrine and paracrine growth factor for epithelial cancer cell lines. In the present study we evaluate the Et production of nephroblastsma cells in culture. A cell line was obtained from pediatric Wilms' tumor. The cells were grown and established in TC 199 culture medium, and then characterized by phase contrast microscopy, electron microscopy and immunocytochemestry. Et level was measured in triplicated on surnatants collected at I, 3, 6, 12, 24, 48 , 72 hours after the start of the culture, using a radioimmunoassay for human Etx and Et~. The cells, under Ig FCS condition, released Et as function of the time, reaching a plateau of 25 pmol/L •215 ~ ceils after 24 hours. Insulin added to the culture medium at the concentration of 5 ~g/ml does not significantly modify the Et production, but induced several changes of cytsscheletric pattern of these cells. A lack of desmin staining and an increase of cytokeratin and laminin positivity were revealed. After addition of 10 "~ M synthetic Etx to the culture medium, we bbserved a progressive reduction of cytokeratln and laminin positive cells, with unchanged staining for fibronectin, desmin and vimentin. Myosin and actin were always negative. The effects of Insulin and Et on this cell line will be discussed. Glomerular fibrin deposits may be the result of a dysfunctional plasminogen activating system. Since neutrophil elastase is a major proteolytic and bieregulatory protein, we examined its effect on the mesangial plasminogen activating system. Rat mesangial cell monolayers were incubated with 0 to 27.5nM of enzymatically active elastase or elastase inhibited by diisopropyl fluorophosphate (DIP-elastase), with or without fucoidan (binds to elastase receptor) or cycloheximide (blocker of protein synthesis). The plasminogen activating activity (PAA) was determined in cell extracts and in serum free conditioned medium.

Elastase and DIP-elastase caused a concentration dependent increase in PAA. As little as 0.43nM of elastase increased PAA in cell extracts by 67%. Similar level of PAA in cell extracts was maintained between 0.43nM and 3.4nM. Further increase in elastase concentration up to 27.5nM caused a gradual decline in cellular PAA to the baseline level. In the medium conditioned by cells exposed to elastase the PAA gradually increased up to three fold with 0.43 -6.SnM and remained unchanged between 6,8 and 27.5nM. Exposure of cells to DIP-elastase caused a gradual, concentration-dependent increase in PAA up to 19-fold in the conditioned medium.

Same concentrations of active and DIPelastase had no direct effect on plasminogen activation. Cycleheximide inhibited the enhancing effect of elastase and DIP-elastase.

Cycloheximide by itself had no effect on PAA. In contrast, fucoidan by itself had a stimulating effect on PAA comparable to that of elastase. Our results demonstrate that enzymatically active and inactive forms of neutrophil elastase modulate the mesangial plasminogen activating system and cause an increase in the net PAA. These findings suggest that the release of elastase by neutrophils in the glomeruli may enhance the lysis of glomerular fibrin deposits. Endothelial cells exposed to cytokines express adhesion molecules that promote attachment of leukocytes to endothelial cell surfaces in areas of inflammation. To defne the potential role of intracellular adhesion molecules (ICAM) and endothelial-leukocyte adhesion molecules (ELAM) in the development of the inflammatory response in the glomerulus in man, we studied their expression in normal and activated human glomerular endothelial cells (GCEC) and mesangia] cells (MC). GCEC and MC were isolated from normal human glomeruli and propagated separately in serum replete media. GCEC MC and human umbilical vein endothelial ceils (HUVE) were exposed to TNF (3.5 or 50 ng/ml) or IL-1 (1 or 30 U/ml) for 4 hrs. Cells were than stained for ICAM, ELAM, MHC class 1 or MHC class 2 by immunoperoxidase. The number of positive cells and intensity of staining was also assessed by FACS. Cell size of proximal kidney tubules is kept relatively constant by the dynamic action of the Na pump. When the pump is blocked by 1 mM ouabain, cells accumulate moderate numbers of cytoplasmic vesicles, but maintain an intact cytoskeleton and swell only 60% above control. By contrast, ceils accumulate many more vesicles and swell -90% if the microtubule inhibitor vincristine, 5 I-tM + the microfilament inhibitor cytochalasin B, 50 ~tM are used in conjunction with ouabain. Moreover, by transmission electronmicroscopy, the distribution of cytoplasmic vesicles is altered by the cytoskeletal disrupting agents -the vesicles accumulate in the apical half of cells and fail to approach the basolateral membrane. In this study we determined the effect of a high bath [K] on cell swelling, cytoskeletal integrity and cytoplasmic vesiculation. Single, nonperfused rabbit PST were dissected, crimped tightly between 2 pipets in isotonic medium (37~ pH 7.4) and their volume assessed optically with an image splitting eyepiece. PST volume increased massively (by 94% -as much as when ouabain + cytoskeletal inhibitors were used) within 30 rain incubation in a 150 mM [K] bath (n,16). To assess microtubule integrity under these conditions, isolated PST were incubated in an isotonic 150 mM [K] Ringer bath, fixed in methanol/acetone, permeabilized with 0.1% Triton X-100, and stained using anti-p tubulin antibody and FITC-labeled anti-IgG antibody. Control mierotubules appeared as a fine, diffuse cytoplasmic meshwork of fibers, but in'150 mM [K] tubulin appeared collapsed in swirls around the nucleus with loss of the fine reticular pattern. F-actin distribution, assessed by rhodamine-phalloidin fluorescence, appeared concentrated at the apical membrane in control PST with a thin fluorescent band seen along the basal membrane. The high [K] bath caused a more diffuse cytoplasmic staining. Scanning electronmicroscopy revealed vesiclelike structures in moderate numbers after ouabain, but in large numbers after high [K] . We conclude that PST cell swelling in ouabain is limited primarily by the cytoskeleton, and that high [K] allows massive swelling by redistributing cytoskeletal proteins. The sites and extent of glomerular IC deposition and the host immune response required to generate glomerular injury in man is not known. Because of the unique nature of the immune system in primates, a model of primate GN in cynomolgus monkey (CYN) was used to study this process over time. CYN (n=19) received daily IV bovine gamma globulin (BGG) for 8 to 12 wk after sensitization with BGG. Antibody (AB) responses, renal function and the extent of glomerular immune deposits were defined during the induction of acute GN. Each animal had 3 to 5 renal biopsies performed during GN. Results: All CYN developed glomerular deposits by 4 wk. Proteinuria developed by 4 to 8 wk. Severe GN, characterized by decreased GFR and/or heavy proteinuria, was seen in CYN with high AB titers or with moderate AB titers and high antigen excess. Mesangial deposits were most strongly associated with total BGG/kg while GBM deposits were most strongly associated with mean BGG precipitable AB. Severity of GN and proteinuria were related to the extent of LRE (r=0.79) and LRI (r=0.71) deposits and to the total dose of BGG/kg (r= 0.73) and mean BGG precipitable AB (r=0.84). Proteinuria became heavy when GBM deposits were greater than 20 % of GBM surface. Conclusion: The extent and timing of glomerular injury during the development of GN in the primate is influenced by antigen load and magnitude of the antibody response. Proteinurla strongly correlates to the degree of localization of deposits in the GBM. The severity of glomerular injury in primates appears to be more dependent on the host antibody response than total antigen exposure. 1,25-dihydroxyvitamin D3 (I)3) has been shown to suppress the lymphoproliferative response (LPR) of normal peripheral blood mononuelear cells (PBMs). Since chronic renal failure (CRF) is associated with D3 deficiency, this study aimed at evaluating the in-vitro immunomodulatory effect of D3 supplementation on PBMs of CRF patients. PBMs of 18 pre-endstage CRF patients and 8 normal healthy controls were isolated by ficoll-hypaque gradient centfifugation, and cultured in complete RPMI media. LPR to phytohemagglutinin (PHA) (0.5/zg/ml) with and without D3 supplementation (10-SM) was assessed by titriated thymidine uptake after a 16-hour pulse. LPR was measured as the difference between the mean counts per minute (clam) of triplicate stimulated cultures and that of unstimulated cultures. Plasma D3 levels were measured by radioimmunoassay following extraction and purification through a column containing C180H-aetivated matrix. Our results showed that CRF patients had a significantly lower LPR to PHA than controls (p<0.05).

However, 2 types of LPR (Mean+SD epm) to D3 supplementation were seen in the CRF patients :

D3 -D3 + p Controls (n=8) 153328+29693 119427+40549 <0.04 Group I (n= 12)

119246+37824 927014-33450 < 0.001 Group II (n=6) 844764-22128 100517+20572 <0.02 Suppression of LPR by D3 was seen in group I, similar to that in controls. However, LPR to D3 paradoxically increased in group 1I. Plasma D3 levels were normal (> 10pg/ml) in all the controls, 3/12 of group I, and 0t6 of group II patients. In conclusion, although D3 supplementation may improve the LPR in some patients with CRF, this action was probably not a direct effect on lymphocyte proliferation, but rather via a secondary regulatory mechanism. Alterations of the immune system have been described in minimal change nephrotic syndrome (MCNS) but have not been fully elucidated in other forms of proteinuria. Using fluorescent labelled monoolonal antibodies and flow oytometric analysis (FACS) we studied peripheral blood T and B lymphocyte numbers and activation markers in children with heavy proteinuria but without clinically obvious infection. I0( 6-16)* 7(5-12) 6(4-10) 7(4-12) * p less than 0.01 compared with control (t-test) CD8 numbers in MCNS and FSGS were consistently higher than in controls or children with CNS.

Activation of CD4 lymphocytes (CD4/25) was significantly greater in the MCNS group than in other nephrotic patients. The data indicate that both MCNS and FSGS are characterised by an increase in suppressor T lymphocytes (CDS), but only in MCNS was an increase in T cell activation (CD4/25) noted. Culture supernatants of concanavarin A-stimulated peripheral mononuclear cells were comparatively studied in patients with minimal change nephrotic syndrome(MCNS) and in those with some glomerular diseases(GD). Endotherial cell cytosolic Ca ++ was measured using the fluorescent Ca ++ indicator, Fura-2 AM, after being cultured with mononuclear cells culture supernatants. An influx of Ca ++ into cultured endotherial cells was revealed when they were cultured with culture supernatants of peripheral mononuclear cells obtained from patients during the active phase of MCNS. However, no influx was noticed when they were cultured with culture supernatants of peripheral mononuclear cells obtained from patients during the non-active phase of MCNS and with GD. This suggests that in MCNS, mononuelear cell culture supernatant makes endotherial cells contract and cause vascular permeability. The effects of culture supernatants of mononuclear cells on albumin diffusion across the endotherial cell monolayer were examined. Endotherial cells were grown on the bottom of an chemotaxis chamber and leakage of Trypan Blue-Albumin complex(TBAC), which was added in the chamber to the outer well, was measured. Culture supernatants of mononuclear cells in patients during the active phase of MCNS caused TBAC to leak across the endotherial cell monolayer. Those in patients during the non-active phase of MCNS and with GD did not cause TBAC leakage. The lymphokine is suggested to cause an increase in cultured endotherial cell monolayer permeability. In MCNS, endotherial cells were suggested to play an important role in vascular permeability. We have studied the steroid receptors (SR) in lymphocytes from normal children & from those suffering from nophrotic syndromes (NS). Radiostope binding assays (1,2-3H triamcinoloue acetonide) were investigated. In 6 cases isotope binding results were compared to those detected by MAb referred as M7.

The average numbers of steroid receptors/cell in children with steroid sensitive NS was high (11,000+3, 300 SD; 10 patients). In marked contrast, children who did not respond to steroids had low steroid affinity (900-+700 SD; 16 patients). The difference was very significant between the two groups. 15 normal children presented 6,000-+3,000 SD numbers of steroid receptors/ceiL In the 2 groups, the lymphoc'ytes correlated neither with serum albumin nor with protein level.

Since 1987, we have studied the SR receptor display in the lymphocytes from 9 children suffering from glomerular diseases (membranoliferative GN, H-S GN, lupuS nephritis). 5 of 9 patients presented low steroid binding affinity earlier. Later, we found higher SR numbers in the lymphoeytes. 4 of 9 patients presented similar steroid binding aff'~ty during the course of their glomerular disease. Therefore we suppose that the decrease in the number of SR and the steroid resistance arc not definitive. The investigation of steroid responsiveness in certain stages of glomerular disease might be important because it may influence the therapeutic protocol using other immunosuppressive drugs. The aim of the present study was to determine the INF, I L I and LTB4 production by L in children with GN. Material and Methods: 20 children aged 3-14 with GN were included in our study. 12 patients (pts) had neuphrotic syndrome (iNS) • hematuria; 5 steroid sensitive NS (SSNS Group I) 7 steriod resistant NS (SRNS Group H) and 8 pts had isolated hematuria (Group II 0. Renal biopsy was done in 15 cases -11 pts bad mesangioproliferative GN and 4 pts membranoproliferative GN. Control Group (IY) -19 healthy children aged 3-14. Alpha -and gamma -INF production by L were determined by J. Campbell et al. (1975) . I L l production by mouocytes (M) was determined by A. Chamblin et al. (1990) . LTB4 production by peripheral blood polymorphonuclear L (PMNL) was determined by B. Samuelsson (1979) . Results: All pts with GN especially with SSNS had low level of IFN production by L, (Table) . IL-1 produetiun by M was significantly low only in eases of SRNS. LTB4 production by PMNL was increased in pts with SSNS. These data could suggest dysfunction of cellular immunity. Pts with SRNS had impaired L and M function. On the other hand, pts with SSNS bad impaired L function simultaneously with increased LTB4 production by PMNL. Experimental work demonstrated an ability of kidney's mesungial and endothelial cells as well as blood leokoeytes to produce lipid mediators of inflammation> PAF, LTs and monohydroxyeicosatetraenoic acids. One of the significant PAF actions is known to mediate through LTs.

The purpose of the study was to determinate the level of LTs release from the peripherial blood leukocytes under the influence of synthetic PAF in vitro in children with GN. Development of F:VIIIc inhibitors is a rare event in childhood. We report two such cases revealed by haemorragic symptoms. First patient was a 14 years old caucasian boy who started a corticodependant nephrosis at 8, treated for a high threshold with chlormethine, levamisole and then chlorambucil. While on remission under low steroid therapy (.7mg/kg every other day), he presented with compressive hematomas of two legs and gross hematuria. APTr was prolonged (patient: 94"/control: 30"), F:VIIIc activity was less than 1%, and F:VIIIc AB was at 16 U Bethesda/ml. IV Ig (.4g/kg x 5 days) did not change AB titer but coincided with bleeding resolution. F:VIIIc increased slightly under prednisone (1.5mg/kg/d). Subsequent courses of IV Ig (lg/kg x 2d) allowed partial and transient rise of F:VIIIc up to 30%. Despite azathioprine (2mg/kg/d x3 months) and 4 bolus of cyclophosphamide (700 mg/m2), no improvement was seen. After 7 months of oral cyclophosphamide (1,5 mg/kg/d), F:VII/c rose to 20% while F:VIIIc AB disappeared.Second patient was a 14 years old black boy who started a lupus nephritis at 4, treated first by prednisone alone, then by bolus of cyclophosphamide. He has had no flare for 2 years, and remained under low steroid therapy (0.25 mg/kg every other day) when he developped a spontaneous massive hematoma of the right iliac muscle with acute anemia and cmral palsy. ESR was normal, anti-DNA antibodies were low (7%). APTr was prolonged (94"/30"), F:VIIIc activity was at 8%, F:VIIIc AB was present at 8 U Oxford/ml. He received blood transfusion, methylprednisolone (lg/kg), IV Ig (lg/kg once) and porcine F:VIII (Hyate C| In 22 hours, bleeding stopped, APTI" returned to normal, F:VIIIc increased up to 500% and F:Vlllc AB disappeared.APTT remained normal during 4 months, under low prednisone therapy (.2mg/kg/d), when F:VIIIc AB r.elapsed (4U/ml) with prolonged APTT (68"/35") without any symptom.Under IV Ig (lg/kg x 2days), API"r and F:VIIIc returned to normal and F:VIIIc AB disappeared. These results persisted at 6 months. These cases point out the possibility of auto-immune bleeding disorders in children with LED or nephrosis. The prolonged response observed in some cases of F:VIIIc inhibitors treated with IV Ig suggest an effect on auto-antibody synthesis. We examined the levels of IL-6 in urine of 21 children with different forms of GN. Eight patients had steroid sensitive NS, 13 -steroid-resistant. Nephrocalcinosis is a known complication in preterm infants requiring intensive care. The etiology is still on debate; hypercaiciuria due to furosemide and hyperoxalaria secondary to total parenteral nutrition (TPN) are incriminated. We therefore studied prospectively urinary lithogenic and inhibitory factors in 24 infants < 33 weeks of gestation: 16 had TPN, and 8 were fed breastmilk and had glucose-electrolyte infusions (controls). The majority (20) had been mechanicaily ventilated. Each infant received a similar amount of furosemide and calcium gluconate. No dexamethasone was given. Urines were collected during 24 h on day 2 (period a), day 3 and once between days 4 and 10 (period c). Urinary calcium oxalate (CaOx) saturation was calculated by computer program equil 2 according to Finlayson, based on 11 urinary constituents. Renal ultrasonography was performed every second week until discharge. Results: 1) TPN: Ox/creadnine (treat) ratio was persistently high (203 mmol/mol) but not increasing. Ca/creat ratio increased from 1.0 to 1.6 mol/mol. Citrate/creat remained constant (0.45 mol/mol).The urinary CaOx saturation index increased significantly (a:2.6, c:4.8, p <0.05). 2) Controls: Ox/creat increased sligthly from 100 to 145, but remained on a lower level. Ca/creat was considerably lower (0.4/0.3). Citrate/creat increased steadily (0.27/0.58). CaOx saturation at period c was significantly lower (p <0 01) than in TPN (a:2.3 c:1.4). Nephrocalcinosis developed in 2 of the 16 infants with TPN. Conclusion: In the TPN group the increase in urinary CaOx saturation is mainly due to elevated Ca excretion, but the persistently high Ox/creat ratio also plays an important role. TPN infants are at risk for CaOx precipitation and nephrocalcinosis. We investigated the response of urinary calcium excretion to maintained calcium diet restriction in 49 children aged 2.5 to 14.5 years with IH classified according to the results of an oral calcium load performed as previously described (J Pediatr 1987,110:238-243) .

Twenty-five children (51%) were labeled as having absorptive IH, basal Ca/Cr (mg/dl:mg/dl) S 0.20 and postload Ca/Cr > 0.20. Eight patients (16%) were diagnosed ~& renal IH, basal Ca/Cr > 0.20, and 16 (33%) children of undetermined IH, basal and postload Ca/Cr S 0.20. During a follow-up of 3.0• years (XISD) 24-hour urine calcium elimination (UCa) was measured every 3 months while patients were receiving a diet without dairy products. In children with absorptive and undetermined IH, UCa significantly (p < 0.005) decreased from 6.6• and 6.411.9 mg/kg/day to a mean value of 3. 

Hyperuricesuria (HU), an important lithogenic factor has not been investigated as a possible etiology of hematuria in pediatric patients. We have prospectively studied for 6 to 30 months, 30 children (15 male, 15 female; aged 3 to 13 years old) with previously undlagnosed isolated hematurla in which HU was found. Positive familial history of nephrollthiasls was found in 40% Idiopathic hyperealciaria (IH) (UCa >4mg/kg/day) was found in 0% of the patients at the beginning but after 6 to 24 months, 20% presented it. They were submitted to the following treatments: purlne restricted diet (13%), allopurinol (4%), potassium citrate (1%) and no treated (83%), Treated children presented normal urieosuria and hematuria resolved completely as soon as uricosuria became normal. In the non-treated group, 13% and 6%' developed urolithiasis after 6 and /2 months, respectively. We coneinde that HU, llke IH, can theoretically produce micro calculi that damage the renal tuball with consequent hematurla. Furthermore, the recognition of this association will prevent unnecessary and, in some eases, invaslve diagnostic investigations. The treatment of this group may prevent renal stone formation. We studied the long-term evolution of 36 children, 22 males, with IH. At diagnosis, children's age ranged from 2.8 to 12.7 years and the urine calcium excretion (X+SD) was 6.5+1.7 mg/kg/day (range:4.3-13.0). Main presenting manifestations were recurrent abdominal pain, macroscopic hematuria, and lower urinary tract symptoms found in 13, 13, and 8 children, respectively. Four patients had passed renal stones and/or had urolithiasis detectable by ultrasounds or X-ray films. Three children had subnormal growth. During a follow-up of 4.0+2.0 years (range:l.5-9.7), physical examination of patients and biochemical analysis were performed every three months. Image studies were repeated yearly. Suppression of diet's dairy products resulted in normalization of calciuria and remission of clinical symptoms in 27 children (75%). One child developed new stones. Growth rate of patients did not change. Reintroduction of normal diet after at least one year of normocalciuria caused recurrence of hypercalciuria in 15 children. Twelve patients remained normocalciuric in the presence of ,normal calcium intake. This report shows the evolution of children with IH and serves to emphasize that IH is transient in 30% of patients in which normalization of diet resulted in no reappearance of IH. In order to determine the in~uence of different risk factors end protective inhibitors on lithogenesis, we have studied 25 children with idiopathic lithiasis(IL) and 20children with idiopathic hypercalciuria(IH).Hyperparathyroidismo(HPT),tubular diseases,urinary tract infection(UTI),urologic disorders and vitamin D or calcium supplements were discarded. Urinary measurement of calcium oxalate(UOx),citrate(UCit),magnesium (UMg),uric acid(UUA) and creatinine(UCr)were made.Renal function was cosidered too. The children were studied as out patients,(having normal diet,with respect to protein and salt supplemental. Results were compared to those found in a control group(CG) of similar age.They were es~ressed as arithmetical 9 .

-.

- Nephrolithiasis, which is an unusual finding in infancy, became a common pathology among the very small prematures. We report the incidence of nephrolithiasis in a population under ]501 g delivery weight, during a 4-year period. The ultrasonic survey was started after nephrolith-iasis was diagnosed in a premature infant with gross hematuria. Gradually, all infants born less than 1501 g were screened by real-time ultrasound. The ultrasonography was done during hospitalization and/or before discharge home. Between September 1987 and September 1991, ]81 premature under 1501 g were born and 137 (75.7%) survived. Ultrasonic evaluation was done to 77 of these prematures and renal stones were found in 25 of them (32.5%). Delivery weight of the group was 994 • 208 g (630-1400). The gestatio-nal age was 28.7 • 3.1 weeks (24-38) and the diagnosis was obtained between age of 25 days to 5 months (mean 2.67• m). All the infants required mechanical ventilation and bronchopulmonary dysplasia was diagnosed in 14 of them. Furosemide total dose administration ranged between 0-18.5 mg/kg (mean 5.65• All the group received total parenteral nutrition 5-38 days, delivering 30-40 mg/kg/day of calcium gluconate. Enteral feeding based on special premature formula delivered daily 62-146 mg/kg of calcium. One infant received a supplementat-ion of ~90 mg/kg/day of calcium p.o. due to severe osteopenia. This condition was observed in 10 of the prematures. During a follow-up of 1 to 9 months the calcifications disappeared in ]7 (68~) of the patients. Three patients were lost to follow-up and 5 are still under observation. Due to the high incidence of nephrolithiasis in the very low birth weight population, we emphasize the need for routine ultrasonography screening before discharge home. Patients on HD have poor exercise tolerance and decreased muscular strength.

Carnitine has been suggested as a therapeutic agent to improve muscle function and exercise performance.

We studied muscle strength and physiological response to dynamic exercise in 9 adolescents on chronic maintenance HD.

Patients were randomly assigned to a sedentary (S) or exercise (E) group with either L-carnitine or placebo added to the dialysate on each group for 12 weeks followed by a cross over.

Serum triglycerides (TG), total and HDL-cholesterol and plasma free (FC) and total carnitine (TC) were measured before and after each period. The exercise period consisted of cycling for 32 min., in semirecumbent position during the first hour of HD.

A graded exercise stress test was performed to determine maximum oxygen uptake (V02 max), time on test (TOT) and workload (WL VO2 max and hemoglobin levels had a significant direct correlation (R=0.79; p<.05). A significant improvement in muscle strength (QS and HS) was observed in E group, which was even greater while on L-carnitine supplementation.

Workload and TOT were also significantly improved in the L-carnitine supplemented E group. A significant increase in plasma FC and decrease in serum TG was observed only in the L-carnitine supplemented group. These results suggest that a supervised aerobic exercise program during HD is safe and beneficial by improving work capacity and muscular strength. L-carnitine supplementation improves hyperlipidemia and seems to potentiate the effects of exercise in these patients. Urolithiasis is extremely rare among children. Only 2% of all cases with renal calculi present before the age of 15. Since ESWL became the primary treatment for urolithiasis, only 200 children who recieved ESWL for renal or ureteral stones have been reported in the medical literature. During the last six years we have treated 58 children with urolithiasis. There were 43 boys and 15 girls, with a mean age of 7 years (range: 15 months -15 years). 5 children had bilateral urolithiasis. Two had complete staghorn calculi, Four had stones in the upper ureter and 9 had distal ureteral stones. Two boys had large stones in the urinary bladder. Stone size ranged between 4 to 35 mm, All children were treated with ESWL alone using the Dornier HM3 lithotriptor. In all cases with stones larger than 2.0 am, a urethral stent or a stent-nephrostomy were placed prior to the initial tretment, to prevent complete ureteral obstruction. 90% of the cases needed only one session of ESWL. Complete fragmentation of the stones was accomplished in 96% of the cases. 22.5% were free of stones within 24 hours, 57.6% within i0 days 80% within one month and 91% of the children were free of the stones in 3 months. In only one case an open oystolitnotomy was performed to remove a large residual stone. No significant complications were encountered following the treatments. The mean length of hospital stay post treatment was 1.4 days. Late side effects on renal growth or function were not encountered durin~ the 6 years of follow up. Hy~oertension was not found during periodic examinations in any of the children. Idiopathic hyperealci,.u'ia (IH) is a common metabolic disturbance in childhood and has often been associated with clinical fmdi~ such as recurrent hematuria and nephrolithlasls. We prospectively studied IH in 20 children with absorptive subtype (AH) submkted to a Ca restricted diet (400-500 rag/day) or rice bran during 6 to 36 months compared to an un-treated group. Bone mineral density (BMD) of lumbar spine (L2-LA) was evaluated each 6 months as well as serum Ca, P, Cr clearance, 24 hour urinary Ca and uriaary cA/rIP excretions. BMD were normal in 16 patients and decreased in 4 at time of diagnosis. Mean UCa that was elevated, decreased after the treatment. Treated ehildren presented increased BMD compared to the tin-treated or uncontrolled children. Additionally 24 and 1,25 vitamin D, PTH and Gla-protein were compared in controlled (UCa < 4 mg/kg/day) & uncontrolled urinary Ca excretion. There was no observed correlation between these parameters as shown in the At the turn of the century the majority of German internists and pediatricians were convinced that for patients with chronic renal diseases there was no better place in the world than Egypt -as long as they could afford the journey. Franz Volhard in his book on Bright's disease 1918 called Egypt with it's dry desert climate an "eldorado" for renal patients. This concept, strange as it sounds for modern nephrologists, had three historical roots: 1) the traditional idea about the favourable influence of heat on renal diseases, already suggested by R. Bright in 1836 and, among many others, by Eduard Henoch in 1881, 2) the close relations of many German physicians like Bilharz, Griesinger, Ehrlich or Virchow to Egypt. It was the German Reil who made Heluan a modern health resort in 1871, and at least three Germans were personal physicians to the viceroy in Kairo in the last century, 3) the publication of the Austrian physician Anton Flora in 1869 about his medical experiences in Egypt. He was the first to conclude that the low urinary output in the desert climate might suggest a reduced work load for the kidneys. Since then the idea of the kidneys "going on holidays" in E~ypt became very popular in Germany. Unfortunately, not all patients survived the dangerous journey, and those surviving did not always show an improvement of their health. So the "holiday theory" became more and more doubtful.

To get a definite answer, four scientists of the Berlin University (A. Loewy, J. Wohlgemuth, A. Bickel and E. Schweitzer) set sail for Egypt in 1914, carrying with them plenty of German mineral water and a mobile laboratory. They analyzed their own urine for volume, concentration, N, PO 4 and NaCI in Heluan, Assuan and Berlin and published the conclusmn that the work load for the kidney is even higher in the desert and that it seemed not too wise to send patients with renal diseases to Egypt. Nevertheless, as late as 1942 Volhard still recommended Egypt as an "eldorado" for renal patients, but now with the exclusion of those in renal failure. P-IB.12 Hereditary renal hypouricemia Is a rare disorder, characterized by low serum uric acid and increased renal uric acid clearance. About 24 cases have been described in the medical literature, six of them in Israel. Most cases are asymptomatic and are diagnosed incidentally on routine serum analysis. Hypercalciuria of the hyperabsorgtive type was found in a third of the cases. Only 5 cases, all adults, presented with urinary stones. Of them 3 had uric acid calculi. We present a 15 month old infant with acute renal failure, anuria and sepsis due to bilateral obstructing ureteral uric acid stones. Initial treatment included insertion of bilateral percutaneous nepbrostomies. Metabolic investigation revealed serum uric acid of 0.4-1.0 mg% (normal for his age -2-5.5 mg%), renal uric acid clearance of 41 ml/min/l.73 sq. m, [normal 7.6-8.8 ) . No other metabolic disorders were found. The diagnosis of isolated renal hypouricemia was made. Extracorporeal shock wave lithotripsy (ESWL) was performed and complete fragmentation of the stones in both ureters was accomplished. Antegrade nephrostograms showed free flow along the ureter without filling defects and the nephrostomies were then removed. Chemical analysis of stone particles collected from the urine yielded uric acid. Metabolic survey of the Child's parents and 8 siblings disclosed 2 sisters and 2 brothers who had low serum uric acid levels and high values of renal uric acid clearance. This patient is the youngest reported case of hereditary renal hypouricemia and the smallest infant who underwent ESWL of ureteral stones. Urinary calcium excretion was evaluated in 56 children ( 24 boys and 32 girls; mean-age 5,3 years) with urinary tract disorders (UTD) other than calculi: 27 with recurrent urinary tract infection (UTI), 18 with non glomerular hematuria, ii with abdominal pain or sterile pyuria or dysuria. First,urine calcium-creatinine concentration ratio (Uca/Ucr) was assessed in urine obtained after a mill or diary products meal to screen for hypercalciuria. In all children with Uca/Ucr> 0,20 the 24 hours urine calcium and ereatinine excretion rate was assessed. Definitive diagnosis of Hypercalciuria (H) was made if Uoa was ~4mg/Kg/day and Uca/Ucr was confirmed ~0,20. To de fine Idiopath~;c Hypercalciuria (IH), causes of secondary H in children were excluded. The subtype of IH (absorptive versus renal)was identified by assessing Uca/Uer ratio before and thereafter an oral calcium load. IH was revealed in 17 children: 4 boys and 13 girls, 13 with the absorptive type and 4 with the renal type, 9 with UTI, 3 ~ith hematuria, 3 with abdominal pain, 1 with sterile pyuria and 1 with dysuria. Our results suggest that a significant proportion (30%) of non calculi UTD is related to IH in children. Nevertheless the ma jority of UTD, in our serie, is represented by UTI and not by hematuria. IH is more frequent in girls (76%) than in boys. The absorptive subtype of IH is more frequent than renal sub-typeS. UUO results in vasoconstriction of the ipsilateral kidney, and vasodilatation of the intact opposite kidney.

To investigate the role of endogenous nitric oxide, an EDRF, in the regulation of renal hemodynamics during UUO, Sprague-Dawley rats were anesthetized for study 24 h after left UUO or sham-operation.

Total vascular resistance (TVR) and renal vascular resistance (RVR) were measured using radioactive microspheres during control periods and following infusion of the nitric oxide synthase inhibitor, L-NAME (2.5 mg/kg). Blood pressure and RVR were increased by L-NAME, with a greater increment in the RVR/TVR ratio of the kidney with ipsilateral UUO than in the intact opposite kidney or sham-operated kidneys.

Infusion of L-arginine (L-Arg), a substrate for nitric oxide synthase, did not alter the RVR/TVR ratio of either kidney of rats with UUO, but reduced the ratio in sham-operated animals.

L-NAME tended to reduce urine flow and urinary sodium and cyclic GMP excretion, whereas L-Arg resulted in a marked diuresis, natriuresis, and increased excretion of cyclic GMP in both operative groups.

We conclude that EDRF activity is increased in the kidney with ipsilateral UUO, which serves to counteract renal vasoconstriction.

This response is not limited by availability of substrate (L-Arg).

Vasodilatation of the intact opposite kidney appears to be mediated by factors other than EDRF. The glomerular filtration (GFR) is a particularly important parameter for the follow-up of children with obstructive hydronephrosis, irrespective of operative or nonoperative treatment. We have earlier got satisfactory results, when measuring the GFR (ml/min) of the individual kidney, using DTPA renography and inulin clearance.

When MAG3 renography was introduced the GFR measurement was not available at the same time. However, to find out if the relative kidney function of MAG3 and DTPA could be correlated both substances were used consecutively during the same examination, adopting Piepsz" method (n=25).

Good correlation was found (r2=0,90) indicating that MAG3 could be used as an indirect measure of GFR in children with obstructive hydronephrosis. Urine prostanoid excretion in neonatal obstructive uropathy was found to be increased together with raised sodium excretion after relief of obstruction (Kfihl et al., Ped Res 27: 103, 1990 ). The present study examined possible side differences of PGE2 and TXB2 excretion and a possible interaction with vasoactive hormones following relief of unilateral pelvi-ureteric junction obstruction. Patients received adequate infusion therapy to guarantee sufficient hydration. In 8 pts aged 0.1 to 13.5 years (median 1.6 years) bladder urine and pelvic fistula urine up to 10 days after pyeloplasty was examined for PGE2 and TXB2, electrolytes, creatinlne excretion. Plasma atrial natriuretic peptide (ANP), renin activity and antidiuretic hormone were determined simultaneously. Median PGE2 excretion was elevated 3-fold (p<0.05) on the obstructed side in comparison to the non obstructed side. It remained high during 10 postoperative days -day 1:35.0 ng/h per 1.73 m' body surface area (range 5.9 to 157.1); day 2:44.7 (17.9 to 115.6); day 10:31.1 (2.9 to 190.4) vs 9.5 (2.1 to 20.1). 5.2 (2,6 to 32,9) ; 8.7 (5,2 to 16,3) . TXB2 was elevated only in some patients (p=N.S.). Plasma hormones did not show significant changes after operation except for a temporary rise of plasma ANP indicating a good response to hydration. No significant correlations were found between PGE2 and sodium excretion, plasma ANP and sodium excretion, and PGE2 and plasma ANP. We conclude that exclusively the obstructed kidney releases high amounts of PGE2 after relief of obstruction. The PGE2 release seems to persist at least during the first 10 days after operation. The extent to which infants with antenatally detected urinary tract abnormalities should be investigated posmatally remains controversial. Urinary tract abnormalities were detected on obstetric ultrasound in 86 babies.

Thirty-four babies were referred from other hospitals. The remaining 52 babies, including 7 still births, were born at our institution in 2 years to November 1991 (incidence 0.6%). Significant pathology was confirmed postnatally in 33 of these 52 babies (incidence 0.38%). All 79 live born infants were investigated by ultrasound, micmrating cystourethrogram (MCUG) and, where indicated, by volume expanded diuretic renography (VEDR). The most common malformations detected were pelviureteric junction (PUJ) abnormalities in 30 (35%) babies, vesicoureteric reflux (VUR) in 16 (19%) babies (isolated VUR 10, associated with PUJ abnormality or contralateral hypoplastic kidney 6), multicystic kidney in 6 (7%) and duplex system in 6 (7%) babies. Twentyone (24%) babies were normal posmatally. Of 39 kidneys (29 live born infants) with PUJ abnormalities, 20 kidneys (14 babies) required pyeloplasty while 19 kidneys (15 bhbiesy remained stable or improved over 3-27 months of observation. Foetal renal pelvic antero-posterior diameter (PD) and renal pelvic/renal antero-posteriur diameter (PD/RD) ratio were measured in 47 hydronephrotic kidneys. Posmatally 6 of 26 kidneys with PI:~_ 10mm and PD/RD <0.5 had significant abnormalities (VUR 4, transient PUJ hold-up 2). Nineteen of 21 kidneys with PD >10mm and/or PD/RD ratio >0.5 had significant pathology. In conclusion since important uropathology causing foetal hydronephrosis can be predicted from foetal renal and renal pelvic measurements, VEDR may be restricted to babies with elevated values. However since measurements do not predict VUR and VUR may be associated with other abnormalities, MCUGs should be performed in all babies with antenatally detected urinary tract abnormalities.

The reason for this is unclear and several mechanisms may occur. It may be due to a direct effect of the bacteria. The aim of this study was to detect renal defects in children with UTI without obstruction or VUR and normal renal function.We investigated 76 children (54 girls Possibly, the modifications of the trace elements concentrations in urine is one of the most important factors which promoting a chronic course of urinary tract infections. We studied the decrease of copper concentration in urine in children with chronic pyelonephrltls by atomic absorption specerophotometry (Labtest, FRG). We inveStigated the effect of copper sulphate on adhesion of E.coli to uropithelinl cells (UC) in vitro. The cytological material we reeelved by scraping off urethral surface. The UC were three times washed and re-suspended in Tris-buffcr (pH 7.4), then reduced to the concentration 11){){}(}00 UC per lml. The culture of E.coli was grown during 24h at 37C on the dense minimal encentration of copper sulphate (experiment) and without of them (coutrol). The main stages of the adhesion test were: incubation of lml UC with lmi of bacterial weight during 111 with constant shaking; filtration of non adhering E.coli; preparation imprints -smears for microscopic ~'~mlr)ation; staining & quantitative analysis of adhesion through light microscope. For e~timation of the adherence activity we used adhesion number (AN) -the middle number of E.eoli, which adhered at one UC and adhesion index (AI) -the percent of UC with 20 or more E.coli on its surface. We determined that the growth of E.coli on the environment with copper sulphate depressed the adherence of E.coli to UC. AI in experiment was in 12 times, and AN -4 times lower than in coutrol. We investigated the relationship of NAG, BMG and ALB levels in spot urines and RMC in patients with UTI. 7 patients were divided into 6 groups according to unilateral (13) or bilateral (13) vesico-uretcral reflex (VUR) with or without RMC including hypo or dysplasia and scar formation, which were determined on IVP or DMSA scan. These consisted of 0) U-VUR without RMC (UN), (2) U-VUR with RMC (Ur), (3) Uhydronephrosis due to PU stenosls (UO), (4) B-VUR without RMC, (5) B-VUR with mild RMC (Br), (6) B-VUR with moderate to severe RMCV (BR). 61 cases served as controls (NL). The items of measurement were creatinine (Cr), NAG, BMG, ALB and those values were expressed as Ct ratio. The results suggested that the mean values of NAG, BMG and ALB were lower in order of UN, BN, UO, Ur, Br, BR group (Table) . The patients in B-VUR were more affected than those in U-VUR. The sigulficant differences of those levels were observed between BR and other groups. The incidences of the patients with abnormal high value (> +2SD) are shown on the Vesico-ureteral Reflux (VUR) is an important cause in recurrent urinary trace infections and renal scarring which progresses to reflux nephropathy with specific clinical findings.

In this paper, 102 children were evaluated retrospectively. 64 patients were female (62%) and 38 patients were male (38%). Median age was 6.7 years (5 months -14 years old). Average follow up time was 4 years and I month. Grading of reflux was done according to the international Reflux Study Group with MSUG in all patients. Either proteinuria (> L0gr/L./day; hypertension ~ > 90 percentile), chronic renal failure (GFR < 30 ml./MnJ1.73 m ~) and renal scarring were investigated with radioisotope imaging (DMSA) and classified according to the degree Of scarring. The patients with VUR comprised of those with I degree (13 cases), lI degree (22 cases), Ill degree (33 eases), IV degree (23 cases), V degree (11 cases): Proteinuria in 25 patients (24%), hypertension in 20 patients (19%), ehronie renal failure in 17 patients (16%) have been observed. Renal searrlng was demonstrated with radioisotope imaging (DMSA) in varying localizations in 72 patients (71%). Renal scarring was not detected with US in 27 patients (26%) and with 1VU in 20 patients (29%) among these 72 cases with renal scarring. Medical treatment was given in I (13)," II (20), HI (15) degree groups and reflux completely regressed. Surgical therapy was performed on II degree with bifid ureters in 2 patients, llI degree (18), IV degree (18), V degree (5) eases. The rate of success of ~mti-reflux surgery was 86%; 11 patients had chronic renal failure.

The patients were saved fi'om renal scarring with effective medical therapy or surgical treatment in vesico-ureteral reflux.

Investigations of s~tl'ing with DMSA scan have been compared with US or IVI.I techniques. Since these last techniques might show false/negative outcomes, investigation of scarring with DMSA scan was accepted as a gold standard. We followed 18 patients (1~ boys and 4-girls) with hepatitis B virus(HBV}-associateci nephropathy to discover the long-term prognosis. The main initial urinary finding was hematuria and proteinuria (72.2%). In 8 patients (4/4-.5%), nephrotic syndrome occurred during the course of disease. These 8 were treated with predonizolon and 3 patients achieved full remission. Histological studies confirmed membranous nephropathy in 10 patients (55.6%), and membranoprolifevative glomerulonephritis in 2 patients(1 l.l%). During the Iollow up period (range #8-1#4 months), 11 of the 18 patients (61.1%) with positive HBe antigenaemia showed seroconversion of eantigen. A total 15 patients revealed an improvement in the urinary findings, whereas 3 patients showed no improvement. Two of these three patients without any improvement in urinar/ysis developed end-stage renal failure and required maintenance dialysis. The seroconversion of HBe antigen and the pathological findings did not influence the long-term prognosis for the urinary findings or end-stage renal failure. Our results suggest that HBV-associated nephropathy ha~ a favorable prognosis. However, the patients with no improvement in urinary findings had a high probability to develop end-stage renal failure. A long-term follow-up is continuing for these patients. Staphylococcus saprophyticus is a common cause of urinary tract infections (UTI) in young, fertile women but little has been published about the occurrence in children. We therefore studied the clinical characteristics of S. saprophyficus UTI during childhood. Among 1500 children below 16 years of age attending an outpatient UTI clinic 1976-1987, we identified 59 children with S. saprophylicus bacteriuria. The majority were teenagers but II of 45 girls and 9 of 14 boys were under 13 years of age, the youngest being I year. All the infections were symptomatic and the clinical characteristics were similar in girls and boys. The typical presentation was acute dysuria, back or flank pain and temperature below 38.5~ In the majority C-reactive protein was low. The maximal renal concentrating capacity was transiently reduced in half of the children. Urography, performed in 37 children, showed no case with renal scarring or other important anomaly. Recurrences occurred in 14 patients, in 6 of these S. saprophyticus was the cause. We only included cases with significant bacteriuria (>100,000/ml) in our study. However, because of the tendency of these bacteria to form clusters, the number of colonies identified is usually low. Therefore a cut-off level of 10,000/ml is often used. The number of children presented here therefore represents minimum figures. ! Conclusion: Children with S. saprophyticus UTI mostly present with acute dysuria accompanied by back or flank pain without high fever. They seem to constitute a low-risk group with few anomalies of the urinary tract. is .%~e~ss=rj ia p~tic:~ts :.,ith recurrent '~ri.~ar2 %r.~c% i.lfac-tioi~ (U~I), especiall b' in %i_ose :~itb vevicour~Taral r{~fi~x. 9:c:; drugs .;re k-~_o:;-n to be _~uiT/z.!e f~r %]qs )urpoR~, 9uragi< (z3.) is PLTher 7i~]~!a utTe~ .~;:., 7a uro-:.atJteptic "!.~ this countr 5. It has been suggested that small numbers of bacteria frequently reach the bladder by ascending up the urethra but do not result in infection due to the defence mechanisms of the bladder. The purpose of this study was to investigate the occurrence of short episodes of bacterial colonization of the urinary tract in healthy infants. Urine samples were obtained by adhesive bags weekly for ten consecutive weeks from infants attending a Child Health Center. Those with growth of >50,000 colony forming units/ml with one dominating strain were asked to do suprapubic aspiration for confirmation of bacteriuria. Mter informed consent 96 families accepted to participate, starting age 1-7 weeks; 89 infants completed the study, 51 boys and 38 girls. A second study period during the second half of the first year was completed by 22 of the 38 girls. 18 infants were reexamined because of suspected bacteriuria which was confirmed in 7, 2 boys and 5 girls. The isolated bacteria were 5 strains of Escherichia coli and one each of Proteus mirabilis and Enterobacter cloacae. All the bacteriuric children were reported to be healthy and had C-reactive protein <6 mg/1; 3 had transient pyuria with >50 leukocytes/mm 3. Ultrasonography was performed in 6; no abnormality of the urinary tract was found. The 2 boys were found to have bacteriuria at the age of 2-3 months. Of the 38 girls studied during the first six months of life, none had bacteriuria; during the second six months period 5 of the 22 had short periods of bacteriuria. All the bacteriuric children remained asymptomatic and spontaneously eradicated the bacteria, in 5 of the 7 cases within two weeks. Conclusion: Transient bacteriuria is not unusual in healthy infants. Renal tuberculosis is a late sequel of primoinfection and rarely found in childhood. Although the renal parenchyme colonization occurs during the non-immune haematogeneous phase, the clinical manifestations have usually a late onset.

We report this condition +in 4 female patients, non immunized by BCG, aged 8-0,4(5-11) years with a follow up of 3,75 +0,2(1-7) years.

The presenting symptoms were macroscopic haematuria in 4/4, dysuria and frequency in 2/4 and recurrent renal colic in 1/4. The diagnostic criteria were positive urine cultures for acid fast mycobaeteria and a positive tuberculin allergy test.

The renal imaging study included intravenous urography (IVU), renal ultrasound, micturating cystogram and DMSA tc 99 scanning.

The IVU was abnormal in 3/4, (polar scar in 1/3, renal atrophy 1/3, hydronephrosis 1/3), however on DMSA scannning, renal scarring was present in all the children.

Patients were treated with isoniazide, rifampicin and etarnbutol for 12 months with remission of the clinical manifestations and negative urine control cultures.

In conclusion, renal tuberculosis although rare in children, is a condition to be considered in the differential diagnosis of recurrent macroscopic haematuria. Renal Na handfing is supposed to be disturbed during acute pyelonephritis (APN) in children. The reason for this disturbance is still debated. The aim of the present study was to evaluate changes in Na-homeostasis in children with APN in relation to pyelonephritic changes visualized with 99Tc-DMSA scan (DMSA), an indicator of proximal tubular function. 72 children, 59 girls and 13 boys, 0.2-15.9 (median 1.1) years of age with APN were studied. Blood and urine samples were taken on admission, DDAVP test with determination of osmolality, Na and urea in the urine and DMSA were performed within 5 days from admission. The uptake of DMSA was quantitated with a computorized method. GFR was estimated with formula clearance. 62 children were reinvestigated approximately 2 months later. In a few children fractional proximal reabsorption (FPR) and fractional distal reabsorption (FDR) were studied with lithium clearance and tubular phosphate reabsorption (TPR). Results: The mean CRP was 108 (range 10-320) rag/1. S-Na was 137• (range 128-145) mmol/1 during infection, lower than at follow-up, 139+3 (range 135-152) mmol/l (p< 0.02). Plasma aldosterone was higher during infection than at follow-up, 971+506 vs. 294+221 pmol/L GFR was lower during infection than at follow-up, 75_+24 vs. 83_+19 ml/min/1.73 m2, (p<0.02). TPR was lower during infection than at follow-up, 85+8 vs. 93+3 %. FPR during infection was low 55,8-66,4% and FDR was high 99,1-99,2%. Mean max. urine osmolality (MUO) was lower during infection, 533-+173 mOsm/kg, than at follow-up, 774+164 mOsm/kg (p<0.001). MUO was closely correlated to uUrea both during infection (r=-0.76, p<0.001) and at follow-up (r=0.81, p<0.001). MUO was not correlated to uNa during infection (r=-0.17, p=0.26) but at follow-up (r--0.54, p<0.001). S-Na during infection was inversely correlated to both CRP and changes on DMSA (r=--0.42, p< 0.01 vs. r=--0.31, p<0.05). There was no correlation between s-Na and GFR. We conclude that during APN in children there is a proximal tubular dysfunction that may lead to disturbances in Na reabsorption. It is suggested that this may lead to hyponatremia when the capacity of the distal tubule is overriddeq. Hypertension is believed to complicate vesicoureteral reflux (VUR), but the incidences is unclear. This study was designed to determine the prevalence of hypertension in children with primary, uncomplicated VUR and to study the relationship between blood pressure (BP), grade of reflux, age at diagnosis, number of urinary tract infections (UTI), renal scarring, treatment modality and duration of reflux. Subjects were identified retrospectively from chart reviews between 1974 and 1991. Follow-up was measured by the Dynamap 1800. All cystograms, intravenous pyelograms (IVP) and renal ultrasound were read independently by a single blinded observer.

Of 396 eligible patients, 10 declined to participate and 236 were lost to follow-up. 150 patients were studied and 4 were excluded because their cystograms were unobtainable. Of 146 subjects, 129 (88.4%) were female and 17 (11.6%) were male. The median ages at diagnosis was 5 years (yrs), and at follow-up was 16 yrs. The median length of follow up was 120 months. Cystograms performed at the time of diagnosis documented grade I reflux in 12.4% grade II in 45.5%, grade III in 31.7%, grade IV in 8.3% and grade V in 2.1%. 41.8% of patients received medical treatment only, 33.6% underwent ureteral reimplantation, and 20% required both surgery and subsequent antibiotics. Reoal scarring on IVP was found in 30.8%, no scarring was found in 56.8%. At follow-up, the median systolic BP was at the 32nd %tile and the median diastolic BP was at the 10th %tile.

There was a trend toward higher BP %tiles with grades IV and V reflux, but values were no higher than expected norms. None of the patients registered BP over the 95th %tile.

In conclusion, primary, uncomplicated VUR, regardless of severity, number of documented UTI's or the presence of renal scarring, was not associated with development of hypertension over a median follow up period of 10 yrs of both medical and surgical patients. The colonization of the periurethral flora has been considered an important factor in the interaction between the host defenses and the invading bacteria. Objective: This study was designed to provide information on the composition of the periurethral flora in healthy newborns and to to assess if there is a seasonal influence on it. Newborns: Seventy-five healthy newborns (25 males, 50 females) were studied 24 to 48 hours after birth, at the Nursery of a main teaching hospital. Method: A moistened swab was used to collect samples from the periurethral area and urethral meatus. The swab was then inserted into a transport medium and sent promptly to the laboratory. Samples were obtained in August 1989 (n=30), March-April 1990 (n = 22) and July-August 1990 (n = 23). Results: The cultures were negative in 19 newborns (25%). In 21 (28%), both gram-positive and gram-negative bacteria were identified and in 35 (47%), the periurethral flora consisted of gram-positive or gram-negative bacteria. E.cofi and Klebsiella sp were the more frequently gram-negative bacteria found. Streptococcus sp and Staphylococcus sp were the more commonly gram-positive bacteria identified. A significant seasonal variation was seen (p<0.01), both in the presence of sterile culture and in the colonization of the periurethral area with gram-negative bacteria. Conclusions: (1) 24 to 48 hours after birth there is periurethral colonization in 72% of healthy newborns; (2) in 40% of them, gram-negative bacteria are present in the periurethral area; (3) there is a seasonal variation in bacterial growth in the periurethral area and in the composition of the periurethral flora. Objective: the aim of this study was to assess changes in the prevalence and in antimicrobial susceptibility in children with urinary tract infection (UTI), seen at an Out-Patient Pediatric Nephrology Clinic of a teaching hospital. Study design: Urine samples were collected by suprapubic bladder aspiration. Antibiotic sensitivity was estimated by the Kirby-Bauer method. All positive urine cultures obtained during each period were included. From each patient, only the first positive urine culture was considered. The Results: First period: The more prevalent bacteria were: E.cofi (76%), Proteus (13%) and Klebsiella (8%). The E.coli antimicrobial susceptibility was: nitrofurantoin 92%, nalidixic acid 85%, cephalexin 65% and trimethoprim-sulfamethoxazole 40%. Second period: The more common bacteria were E.cofi (82%), Proteus (13%) and Klebsiella (1%). The antimicrobial susceptibility of E.cofi was: nitrofurantoin 95%, nalidixic acid 92%, cephalexin 54% and trimethoprim-sulfamethoxazole 85%. Conclusion: There was no significant modification in the prevalence of the two more common bacteria (E.cofi and Proteus). There was a significant decrease (p<0.05} in the prevalence of Klebsiella. There was no significant change in the antimicrobial susceptibility of E.cofi to nitrofurantoin and nalidixic acid, but there were significant modifications (p<0.05) in the sensitivity to cephalexin and trimethoprimsulfamethoxazole.

RENAL CONCENTRATING CAPACITY IN ACUTE PYELONEPH-RITIS AND AT FOLLOW UP S.M&rild* Dept of Pediatrics, University of Gothenburg, G~teborg, Sweden ~ Objectives: i. To describe the magnitude a n d duration of the defect in the renal concentrating capacity in acute pyelonephritis in children. 2. Assess the concentrating mechanisms in children with renal damage. Patients: A group of 88 children in a longitudinal study were evaluated after their first known acute pyelonephritis. The children were 0.2 tD6 years at inclusion and were followed three years or more. A total of 12 patients acquired or had renal damage. Methods: The desmopressin test (Minirin | F e rring AB, Sweden) was used to determine the renal concentrating capacity. Results: The concentrating capacity was lowered to a mean of -1.5 standard deviation score in the group of patients, as determined by tests during the first 0-5 days after start of antibiotic treatment. Significant lowering lasted until 3 months after the start of the infection. The patients with renal damage had as a group a more profound initial lowering. A normalization occurred after cure of the infection. After two years, children with damaged kidneys had a significant lowering again, this time without any signs of recurrent infection. Conclusion: Upper urinary tract infections i n children cause an initial transient reduction in the renal concentrating capacity. Renal damage after urinary tract infetion was associated whith a long term loss of concentrating capacity, years after cure of the infection. The presence of leucocyturia is not diagnostic of urinary tract infection (UTI). Recently, it has become important in adult patients in the differentiation between colonization and infection. The aim of this prospective study was to assess the value of leucocyturia for the diagnosis of UTI and for the differential diagnosis of colonization and infection in children. Urine was obtained in all patients by suprapubic bladder aspiration. Urine cultures and leucocytes counts were simultaneously performed in the same sample. Leucocytes were determined using uncentrifuged urine examined in a Fuchs-Rosenthal counting chamber. Urine samples from 244 patients (128 infants, 67 pre-school, 49 school-age children; 37 males, 207 females), seen at the Out-Patient Pediatric Nephrology Clinic from a teaching hospital were examined. One hundred twenty two consecutive positive urine samples were compared with 122 consecutive negative urine samples. Leucocyturia was demonstrated in 23 (19%) of the 122 positive urine cultures and innoqeof the 122 negative ones. The negative predictive value of leucocyturia for the diagnosis of UTI, with urine obtained by suprapubic bladder aspiration, is 55%, the sensibility is 19% and the specificity is 100%. Sixteen patients presented febrile UTI. Four (25%) of them had leucocyturia. The negative predictive value of leucocyturia for the diagnosis of febrile UTI is 82%, the sensitivity is 17% and the specificity is 88%. In children, leucocyturia is not useful for the diagnosis of UTI and is also inaccurate for the differentiation between colonization and infection. In the pathogenesis of E.coli in urinary tract infections (bTI) bacterial virulence factors, such as fimbriae, lipopolysaccharides (LPS) and capsular antigens play an important role. Until now 171 different O-antigens (LPS) and I03 different K-antigens (capsule) have be~ml described. We performed a retrospective, epiden~ologic study on E.coli serotypes from 328 chi~dre~l with ~ (M~an age 6.5 + 5.5 yrs). 19.1% of E.coli strains was nos typeable with the available ant isera. Boys (n=84) had 24 different O-types, %4hereas girls (n=244) had 72. The O-serotypes most frequently found were I-2-~-6-7-8-9-15-17-18-25-75 and accottnted for 48.6% of all strains. I_n boys 4--6-15-16-22-25-75-78 O-serotypes were more common; girls had more 1-7-8-9-11-17-77. In the age group < 1 yr "more 2-4-6-75 were found, against 8-9 in the group > 10 yrs. Children with obstructive uropathy (OtP) had significantly more O-serotype 4-6-16-25 and 75, Whereas childre~ with uncomplicated recurrent UTI had more 1-7-11-18. In 37.~ of all E.coli strains a kno~m capsular antigen could be found. KI was the most common K-antigen, followed by K13. K1 was ~nantly associated with O-serotypes i-2-7-18, Ki3 with 6 and 25. Boys and girls had no differemce in K1-serotype, but boys had more K2-5-6-13. The frequency of non-capsular forms was the same in all ~hildren and in all age groups. We concluded from our studies that, with some differences, the same uropathogenic O-serotypes {1-2-4-6-7-8-9-1"5-17-18-25-75) and K-serotypes (i-13) were found as has beetl ~ritten in I iterature. We performed a retrospective study in 15 boys and 25 girls who received quinolones (NorfloxacineR) with special indication for treatment of urinary tract i~fection (UTI). All 40 patients started to have a therapeutic treatment for 10-14 days (9-14 mg/kg/day in 2 dosages), mostly followed by a longer period of profy~actic treatment .(2-6 mg/kg/day in 1 dosage). All 15 boys (mean age 4.5 yrs -range 0.5-13.4) had obstructive ~thy (OtP) and complicated UTI, mostly caused by P~ (n=10). The mean duration of therapy was 48 days. 7 Girls also bad ccmpllcated UTI ((X/P or neturogenic bladder as result of meningom~lelocele (MM [7) , 18 girls had uncomplicated ~ without anatomical or ftElctional abnormalities in the urinary tract. All g~rls had a mean age of 8.2 yrs (range 0. 6-18.8) , and a longer period of treatment (296 days). The most frequent causative organism in girls was E.coli {n=le), mostly a multiresistant strain. 5 girls had Psetr]smcmas UTI. All patients had negative urine cultures after therapeutic treatalmlt with quinolctles. I girl got ~s sepsis with a qu/nolone resistant strain, and 7 patients got a Ulq caused by E~iterococcus during the profylactic treatment period. As side effects in all 40 patients we registered gastro-intestinal symptoms (3), and arthritis of the fhtm~ (i), probably not related to the use of quinolones. Quinolones can be used in c~il~ with OTI caused by Pseudomes Species and multiresistant E.coli. The medication can be taken orally When urosepsis is not suspected, on an outpatient basis. Since q~/inolones are not fully registered in children, prescription should, at the moment, remain in the hands of paediatric specialists. We have investigated individual renal ftmetions in patients with VUR using minas from individual kidneys through a ureteral catheterized stent tube inserted in anti-reflux operations. We measured 24 hours creatluine clearance (24 hr Cer). Fractional excretion of sodium (FENa), urinary B microglobulin index (n-B2MG index), N-acetyl-Dglucosamiuidase (u-NAG index) and urinary macro albumin (u-alb). 24 hour Cer was performed 3 days after anti-reflux operation when urine collection was performed preeisaly without leaks of urine fi'om around the stent tube. 24 hour Ccr was iow and u-B MG index increased in individual kidneys with increasing severity of ~tYR. Increased u-NAG index and FENa did not correlate with the severity of VUR. walb increased in kidney with increasing severity of VUR but not ~i~ificantiy. The degree of u-alb correlated inversity with 24 hour Ccr (0.02 < p < 0.05).

These results suggest that urinary albumin excretion might be a predictive marker of reduced glomcrular function induced by glomemlar damage. The direct assessment of individual renal functions in patients with reflux nephropathy is important in future follow-up because it forecasts that the function of residual normal glomeruli is decreasing due to the hyperfiltration. During the iast 10 years we observed 30 children with urolithiasis (U); 1 case for 120 admiss{ous. They ranged from 0.9 to 15.4 years; 20 were boys (66%) and 10 were girls (34%). Complete clinical and metabolic evaluation was performed and etiology was identified in all the patients. 26 had metabolic disorders (86%): IH in 12, homozygoas eystimtria in 8, hyperoxaluria in 3, hyperurlcosuria in 2 and liypocitraturia in 1. Three pts had infectious calculi and 1 had urinary tract malformation. Positive family history for U was present in 21 pts (70%). Treatment included llthotripsy (ESWL) and/or specific medlcal-dletedc measure (high fluid intake; dietary Na restriction and thiazide diuretics in Ca U; alpha MPG at a dose of 30MG/Kg/Day and urine alkaEnization in cystinuria; low dietary ox,'date + magnesium oxide in hyperox). Recurrence of calculi occurred in 5 pts with calcium U (51%), in 2 with cystinuria and in all the pts with hypcroxaluria.

Urinary excretion of renal stones promoting (Ca, urie acid and oxalate), iuifibiting factors (citrate, Mg, GAGS) and cystlne was evaluated in pts with U and their relatives of I degree (15 control group). Daily excretion of citrate was significantly reduced in pts with calcium U (200 _+ 123 vs 481 + 151 mg/gCr/day-p< 0.05) and oxalate/eitrate x GAGS ratio was higher in these pts (6.7 + 9.1 vs 1.6 -+ 0.6 p< 0.001). Familial hypocitraturia was present in 3 pts with recurrences of calcium U, low cituraturia (<lS0mg/gCr/day) was also found in 2 pts with struvite calculi and in the subject with anomaly of the geuito urinary tract. The other 2 pts with recurrence of calcium U had high values of urinary oxalate (>50rag/day) and of uric acid ( > 20mg/Kg/day). Alpha MPG reduced significantly urinary concentration of free eystine (mean -+ SD 602 + 389 vs 289 _+ 151 rag:day p<0.01) and the recurrence in 2 pts correlated with suspension of treatment. The management of pts with hyperoxaluria remains difficult. Conclusion: etiologic diagnosis of Urolithinsis in pediatric age is possible and necessary for a selective treatment to prevent recurrence. Hypocitraturia represents a predisposing factor for U and in pts with calcium U may be familial. Since proteinuria has been Woven to be the most mbgatiYe Wognosfio marker of R~l, we no,a invesUgated the effects on urinary albumin excretion (UAE) of drugs influencing the renal hemodgnamice. We studied 13 children, (9.8+4.5 ~ears of age) ~ bi~teral vesico-ureterio reflux (VUR) had been previousl9 corrected (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) years before) and with normal ~J~ulin clearance (GFR > 75 ml/min/1.3n3m2). The d~-ee of sc4crin 9 (Srnellie 0 to 4 grade Kidne9 Int 8, S 65, 1975) for both Kidneys was 3.46:E1.7. These childron were sindbd in basal ootKlitien$ a~l r~aluated after 15 d~ls of CEI treatment (Enalaprfl 02 rng/kg) and after 15 addit~l d~s of Wostaglandin inhibitor

U~ was significant~ h~er than controls in basal ~enditiens (59.8• pg/min, vs 2,5• After CEI treatment mean UAE skjnifioently deorear, ed (i8.3i33.8 I~g/min, p<O.02) while OFR was substential]y um'nodifled (109A+~ in basal r vs 105.5~37.6 ml/min/1.73m2 after CEI) Converselg, IN treatment did not reduce s~nif~ant~ U/d"-yalues (10.1 ~:18.5 ~g/min, p nmS.) while decreased signifioantkj 6FR (93.09~33.12 ml/rnin/1.7~2, p<O.05). ~t'e found a sioJdfioant correlation between the entit W of renal soarr~ axl the decrease of UAE on Cs theralxJ (r=O.5, p<O.05) but not en IN (r= 0.27, p n.s.).

Our data ~licate that microalbuminurla characterizes some chiklren with ~vere RN. Ifi these cases a treatment with CEI can reduce UAE, poss~bl~ influenoin9 th# evolulion to ronal failure.

excretory urography and renal uitrasonography. Typically when these studies are normal additional Imaging studies or follow-up is not routine, However, recent evidence has suggested that any child with proven acute pye/onephritia /s at risk for parenchyma/ scarring, whether or not vssicouretaral reflux Is present. Since cortical renal sclntigraphy has a proven abi/ily to demonstrate renal Inflammation, we compared cortical renal scintlgraphy with our standard imaging protocol (voiding cystourehrography and renal u/trasonography) /n 46 children with documented acute p~elonephritis in order to assess which technique was superior in detecting patients at risk fnr renal injury. Cortical renal scintigraphy was abnormal in 36 children (78%) and renal ultrasonography in 5 (11%) . Vesicoureteral reflux was demonstrated in only 20 (43%). We conclude that co~'cal renal scintigraphy is the preferred imaging technlque for diagnosing acute pyelonephritis, and should be part of the routine evaluation In every child with suspected acute pyelonephritis, A new Imaging protocol incorporating cortical renal scintigraphy will be outlined, Patient 2 is a girl with a family history of SLE and complement deficiency. The disease began when she was 11 and was always controlled with steroids. At 13 years of age, she developed haemolytic anemia, severe digestive tract involvement requiring parenteral nutrition support, and bladder manifestations. She suffered from suprapubic pain and urinary incontinence. US revealed a large bilateral ureterohydronephrosis and an important thickening of the bladder wall ; the severity of the cystitis was confirmed by cystography and cystoscopy. The obstructive uropathy required bilateral ureteral catheter stents. The pathological examination of the bladder showed mild inflammatory infiltrate, arteriolar thrombosis and necrotic zones. The patient was treated with prednisone + cyclosphosphamide and had a favorable outcome. SLE cystitis is rarely described : less than 20 cases are published in adults. Urinary bladder involvement may be a primary manifestation of SLE but often occurs after several years of evolution under steroid therapy without cyclophosphamide, such as in our observations. All the patients had laboratory evidence of disease activity and most of them had profound gastrointestinal complaints concomitant with bladder symptoms. In our patients, despite ureteral catheterization in one case, the urological involvement was controlled with steroids • cyclosphosphamide ; however persistant urinary symptoms or bladder fibrosis have been reported. Lupus cystitis may be more frequent than thought and could be considered in children with SLE and lower urinary tract findings.

]. Kadowaki*, S. Hoshii, C. Igarashi, W. Abe, Department of Pediatrics, Nishi-Sapporo National Hospital, Sapporo, Hokkaido, Japan.

A great change of proportional incidence of various renal diseasns has been observed for the past 2 decades in Japan. Tlfis study was designed to evaluate any change on the incidence of poststreptococeal glomerulonephritis (PSGb 0 and steroid sensitive nephrotic syndrome (SSNS) in children of north Hokkaido, Japan.

Questionnaires asking for the patient number admitted for the two diseases between 1978 and 1989 were sent to 46 hospitals with pediatric in-patient services in November 1989 and were collected by February 1990. The recovery rate was 87%. The incidence of PSGN decreased markedly from 1982 to 1985 and that of SSNS although decreased showed unremarkable change. The similar trend was observed in main land Honshu, Japan. In Hokkaido, the incidence of PSGN per 100,000 population was estimated 12 in 1980 and 2 in 1987 and that of 8SNS was estimated 10 in 1980 and 6 in 1987 in children.

In condnsion, a decrease of disease incidence was observed in PSGN and SNSS in children in north Hokkaido, Japan. This decrement was more remarkable in PSGN in recent years. Hypothalamo-pituitary-gonadal (H-P-G)funotion was evaluated in prepubertal children with CRF,17 males(M) and 7 females(F).In the M group(G), 5 patients were on conservative treatment(CT), 4 on chronic dialysis(CD),CT/CD MG,and 8 after O.5TO 3.5 years of renal transplantation(RTG). In the FG, 2 were on CT and 5 on CD, CT/CD FG. H-P function in M was studied after a iv GnRH test. In CT/CD MG but not in RTG, serum FSH(X• at 60min was significantly lower than in M prepubertal controls (C~,n=18) 2.53+1.84 Vs 6.25+2.84IU/L respectively, p(O.Ol. Testosterone (T) steroidogenie capacity was evaluated after one week of hCG stimulation while androgen sensitivity was studied by determining the decrease of serum SHBG one week after im administration of 2mg/Kg T ennanthate (TE). Normal increment of serum T and normal decrement of serum SHBG (below 80% of basal value) was found in CRF, and no difference between patients on CT/CD and after RT was deteeted(T:17.2+13.6 and 9.5+8.4 nmol/L,SHBG 51.7+4.9% and 62.2+17.9% of basal7 respectively). H-P-G function-in F was stud~ed after IVGnRH test and after 2 so doses, lOOug of aGnRH (Buserelin) at 24hs interval. No difference between CRFG and C(n=lg) was found ~fter GnRH, but after 4 and 6hs of the 2nd aGnRH serum FSH was significantly lower in CT/ CD FG than in C(n=7), p~ 0.02. In C serum Estradiol levels increased above 55 pmol/L in 6 of 7 C subjects. In contrast, in CT/CD FG, only 4 of 7 showed similar positive responses. However, this could not be attributed to ovarian hyporresponsiveness, sinoe in two of these 3 patients, serum FSH failed to in crease after aGnRH. This study shows that H-P function is not normal in prepubertal boys and girls with CRF. On the other hand, testioular and ovarian steroidogenic capacity is not impaired and the biological response to androgens is preserved in boys. year of the disease. According to our earlier investigations there is a metabolism-dependent tubular dysfunction in every diabetic patient which starts with.~he onset of IOOM. Oespite the reduced GFR in hyperglycaemic ketoacidosis (1) Renal abnormalities were p~esent at onset in 21 patients and subsequently developed in a further i0. Renal biopsies revealed glomerulonephritis (GN) in 25 patients (WHO Class Ill/IV in 14, V in 4, I~ in 4, and I in 3), interstitial nephritis in 3, and segmental arteritis in i. On repeat biopsy, 8 showed a worsening of GN yet remained in the same class while 1 showed a transition from class IV to V. Unusual complications included bullous skin eruptions, acute airway obstruction from vasculitic oedema of the tongue, femoral arterial thrombosis, interstitial lung disease, and intracranial lymphoma. 14 had negative ANA and/or anti-ds DNA antibodies at presentation. Despite aggressive treatment with prednisolone • azathioprine, cyclophosphamide, pulsed methylprednisnlone and plasma exchange in various combinations, end-stage renal failure developed in 4 and 4 others had chronic renal insufficiency at follow-up. Actuarial survival rates at 5 and i0 yr were 77% (n=13) and 52% (n=4) respectively. Deaths were due to fulminant lupus, pneumococcal necrotising fasciitis, haemorrhagic chickenpox, stroke, myocardial infarction and intestinal perforation. The data shows that SLE in childhood has protean features and a significant mortality and morbidity. RhG-CSF is a glycoprote!n which controls myelopoiesis and is increasingbf used in a variety ot neutropenias. To date, side effects on renal tunction have been reported on rare occasions and these cases have been poorly documenfedo We hereby report a case of biopsy proven .MG which occurred dufin~ rhG-CSF therapy, as well as our studies on me in vitro effects of rhG--CSF on mesangial cell proliferation (MC). An 8-year-old boy developea a~ranulocvtosis z months after chmkenpox. Treatment with orarpredNsqne (2mg/kg/d) and high dose i.v. 1%?_rnunoglob.ulins failed .tocorrectme neutropN1 count. RHG-CSF was administered at an initial dose ot 4,g/kg/d. The dose was increased up to 32#g/kg/d until a response was oSserved and &ranulocyte count normaIizeS. Six weeks later, tile patient presented M(_i with acute renal failure and hypertension. RhG-CSF was discontinued and within 4 days, renal function improved but he became neutropenic again, When rhG-CSF was resumea.at 16ug/kg/d renal function worsened wimin days. Based on temporal assooation between rhG-CSF treatment and occurrence of MG, we postulated that rhG-CSF was inducing MC proliferation possibly by a direct effect, or by means of other mediators. This hypothesis was evaluated with in vitro studies on MC. Rat MC from primary cultures were used for the experiments. Cells rendered quiescent in medium containing 0.5% fetal calf serum(FSC) were stimulated wire various concentrations of rhG-CSF. 0.5% and 10% FCS were used as negative and positive controls, respectively. Cell proliferation was studied with 3H-thymidine incorporation. Addition of rhG-CSF in different concentrations did not result in a_ny increase of DNA synthesis of MC. On the contrary, there was a slight tendency towards inhibition. With rhG-CSF concentrations of 5130, 1000 and 2000 mg/ml, we found a 17%, 20% and 16% inhibition, respectively. This was not statistically sienificant (p=0.4). In anomer experiment, MC were incubated for 2~ hours with rbG-CSF. The sup ernatant was then transferred onto fresh cultures of MC. We obser-ve~t a significant inhibition (p=0.001) of MC DNA synthesis. The rate of inhibnion at the various concentrations of rhG-CSF used was 65 "-: 7% (r~G-CSF 500 ng/ml), 62 _+ 6% (1000 ng/ml) and 62 +_ 7% (2000 ng/ml). We postulate that rhG-CSF stimmated MC produce a soluble f~ctor which inhibits DNA synthesis of MC. We are curren@ t~ing to identify this factor. To conclude our results are not in favor of a direct effect of rhG-CSF on the pathogenes s of the glomerulonephrit s observed in this patient. China, 3National Laboratory for 0ncogenes and Related Genes, Shanghai Cancer Institute 22 cases of membranous nephropathy were studied in 162 renal biopsies in children with primary glomerular diseases (13.6%). The age of onset ranged from 3 to 12 years. 19 boys and 3 girls, Among them, 19 cases presented clinically as nephrolic syndrome and 3 eases as nephritis syndrome. HBV markers were tested in sera of all cases, 20 (90.9%) showed positive resul,ts (HBsAg 19/22+, AntiHBs 1/22+, AntiHBc 14/21+, HBeAg 7/14+, AnfiiHBe 1/14+, one case only positive for AntiHBe). HBsAg and/or HBeAg and/or HBeAg were detected in 10 out of 16 cases (62.5%i along the glomerular capillary wall under immunoflureseent-examination. HBV DNA was examined in 4 cases from the renal tissues, digested with EcoR1 and hybridized with 32p labeled HBV DNA probe afte E gel electrophoresis and southern transfer. HBV DNA was present in 2 cases in the integrated form and*~ ~ non-replicating or mu~at~d free form rather than DNA derived from contaminated Danes particles of sera. Only 17 of the renmining 140 patients were serum HBsAg positive (12.1%). These findings ~trongly suggest that membranous nephropathy in children is closely related to HBV infection in China. P-IIA.8

The clinical course of the children with asymptomatic proteinuria is still unclear. In order to assess this, we performed ellnicopathological study on children with proteinuria who visited our hospital through a mass urine screening program (the Tokyo method). From 1980 to 1990, we investigated 150 cases. We divided them into three groups: 96 cases of "proteinuria"; 49 eases of "proteinuria with hematttria"; and 4 eases of "proteinuria with pyurla". The clinical course of these groups were compared with each other.

Consequeudy, 9 out of 96 cases (9.6) "proteinuria" required medical treatment. 1 patient with renal cell carcinoma and one with bilateral hypoplastie kidneys were included in these 9 cases. On the other hand, 33 of 49 cases (67.3%) "proteinuria with hematuria" required urgent medical treatment (ex. glomerulanephrifis).

We examined the clinical features of children with asymptomatic proteinttria. We need to examine and follow the asymptomadc children with proteinuria carefully. Initial complement studies showed a low C 3 of 50.5 (NI 88-195) a normal C 4 of 33.4 and a Low CH~0 of 35 (NI 97-292).

The patient's toxoeara canis tltres were elevated to 1:512.

The renal biopsy showed a lobular pattern with marked mesangial proliferation, thickened and split capillary walls and marked interstitial eosinophil infiltration.

The diagnosis was melabranoproliferative glomerulonephritis Type I. The patient was initially placed on prednisone and Vermox. There was prompt resolution of the eosinophilia and the eosinephiliuria.

The patient was subsequently placed on alternate day Prednisone therapy.

Eight months later his WBC was 11,900 with 3% eosinophils, serum creatioine was 0.6 mg/dl, total protein 6.8 gm/dl, album~n 3.4 gm/dl, and 24 hour urine protein excretion was 72 mg. Urinalysis was negative for eosinophils.

C~ complement was 86.2, C~ complement 24,0 and CHs0 176/m[. A repeat renal biopsy showed improvement in mesangial cellularity, decreased immune deposits and disappearance of eosinophilic infiltrates.

In summary, this is the first report of an association between toxooara visceral larva migrans and MPGN Type !. The patient initially showed a dramatic response to antiparasitic therapy and has shown gradual improvement in renal function and histology on alternate dsy Prednisone therapy. Although there were no significant differences in HbA1C levels during dipyridamole administration, a significant decrease in microalbuniinuria, UB2M, URBP excreflon and GFR was observed without any sigmficant decrease in blood pressure. No significant difference was detected between the initial and control values. This study demonstrated that dipycidamole decreased tubular proteinuria as well as microalbuminuria. It suggested, besides its decreasing effect on intraglomerular capillary pressure, dipyridamole might prevent tubular epithelial ceil injury with its inhibitory effect on oxygen-free radicals. Clinical and immunological studies were performed in 5J children suffering from hepatitie B mediated gloiaeruionephritis /H3V -g~/,treated at t~e ]{ephro!ogieal Department Children'~ Memorial Hospital / durin!j the last q6 years -q975 -1991 /. The grouo consis;ed q <~ out of 575 children with chronic glcmerulenephritin, in whe,n kidney biofsy was evaluated. fhe morphological form of HBV -GN ~;ae membranous .~iomorulonefhritis. Children ~t the on~et of G.( were of the age of 2 to 1:" y, but 19 /]7!;/ wore belcw ]5 y. Clinically all cases were nephrotic syndrome ,with hematuria in JJ cases , persistent hypertension in 6 cases, and impaired renal function Jn ~ cases.

Period of illness prior to our treatment: J-L months, l~revious treatment: ~rednisone(L), cyclophosphamide (3), chlorambucil (2) ;.'ithou~ improvement. Method of treatment: I'rednisone was given ~t a dose of 1-fmg/kg/day, the dose was gradually reduced and changed to alternate-day regimen for I to 2 years. incristine was injected intravenously at a dose of 1.Lmg/sq.m. (0.75-1.5mg) diluted with 2Oral of normal saline,once weekly for 10 weeks. ,%esults:On]y ( cases responded to prednisone. After one course of vincristine therapy., 6 of 8 steroid nonresponders got complete remission.'Khus the total remission rste raised from &2.9~ to 85.7%. During an aversge of hL.a months (7-79 months) 

stay of immunosuppressive therapy. Unfortunately, these drugs are not always effective and have considerable side-effects. In post-transplantation immunosuppression the use of Cyclosporine A (CSA) has improved survival and reduced steroid-toxicity. We therefore retrospectively analyzed 13 children with lupus nephritis who received CSA as part of the immunosuppressive regimen. 9 girls and 4 boys aged 8.4 to 17.5 years (median12.6) were followed for 1.6 to 12.2 years (median 3.5). The ARA-criteda for SLE were met by all but 1 patient, who had a family history of SLE and whose disease was classified as serenegative. Renal biopsy showed Mesangioproliferative GN in 6, MPGN in 3 and Membranous GN in 4 patients. A total of 264 patient months of CSA therapy could be evaluated (Range 3 to 51 months, median 18.2) and compared with 488 patient months without CSA. In all patients the indication for CSA therapy was uncontrolled disease activity under steroids, in 9 patients massive steroid toxicity was present. In 10 children CSA was combined with Prednisone (Pred), 3 children received Pred, Azathioprine (Aza) and CSA. CSA dosage was adjusted to keep whole blood trough levels between 80 to 140 ng/mL During CSA therapy, renal and extrarenal disease activity decreased sigificantly whereas the serological markers did not improve. Mean proteinuria decreased from 786 to 312 mg/sqm/day, creatinine clearance remained stable (100.3 vs 95.5 mllmin11.73sqm). Mean daily steroid dose was 18.7 mg before, 13.2 mg during and 18.1mg after CSA, respectively. The mean frequency of relapse was 0.02/month (CSA+Pred), 0.041/month (Pred), 0.047/month (Pred+Aza). No serbus side-effects were seen under CSA. Infections did not increase during CSA therapy. In one patient a mild elevation of serum creatinine normalized after discontinuation of CSA. We conclude from our data that CSA can be used to intensify the immunesuppressive therapy of SLE and reduce steroid dose and toxicity. The aims in this study were to produce monoclonal antibodies against human albumin and to develop a simple, rapid, and sensitive sandwich ELISA using anti-human albumin monoclonal antibodies for detecting microalbuminuria. Four monoelonal antibodies (MHA-1, MHA-2, MHA-3, and MHA-4) which reacted selectively against human albumin were produced by hybridoma technology. Isotype of each monoclonal antibody was found to be IgG1. All monoclonal antibodies except MHA-I were species-specific on ELISA and immunoblotting. Utilizing inhibition ELISA, it was speculated that these four antibodies recognized respectively 4 different epitopes of albumin. Sandwich ELISA using two monoclonal antibodies (MHA-4 as capture antibody and MHA-2 as detector antibody), which reacted with different epitopes, were developed to detect microalbuminuria. Dynamic range of this assay was from 30 to 500 ~.g/1 and im lower limit of detection was 30 gg/l, corresponding to 1.Sag of albumin per well. The imra-assay and the inter-assay coefficient of variation were 3.3-4.0% and 6.8-8.0%, respectively. Analytical recovery ranged from 92 to 103%. Concentrations of 84 urine samples were measured by the sandwich ELISA and competitve radioimmunoassay. Correlation between two assays was good (r=0.983, p<0.005)over a range of albumin concentration tested. Albumin excretions in 24 hour urine samples from non-insulin-dependent diabetes mellitus patients (mean 16.7rag/day, n=39, 8yr duration) were significantly increased (p<0.05) as compared with those from healthy subjects (mean 5.6mgMay). However, 24 hour urine albumin excretions in insulin-dependent diabetes mellitus patients (mean ll.lmg/day, n=25, 6.8yr duration) were not significantly different from those in normal control. We suggest that this assay has good analytical charaeterisitcs and is suitable and easily accessable for detection of microalbuminuria in clinical medicine. alterationsin the tubular transport of electrolytes. We have investigated the role of hyperglycaemia associated with osmotic diuresis on the albuminuria and renal transport processes of sodium (Na) and phosphates(P).

We have examined 92 children aged 4-19 years with IDDM duration 1,5-13 years.

We estimated the blood glucose and the excretion rate of albumin (UalbV), sodium (UNaV) and phosphate (UPV) in two night urine specimens. The patients were grouped according to i) UalbV: < 12; > 12 ug/min/1,73 m2

2) IODR durations: < 5 years; n=79 > 5 years; n=13.

Renal albumin excretion rates were < 12 ug/min/1,73 m2 in 71 patients and > 12 ug/min/1,73 m2 in 21 children with IDDM. Albuminuria in these groups of patients were not related to the blood glucose values or to the excretions rates sodium and phosphate. Patients with higher blood glucose had significantly higher UNaV and UPV. The values of UNaV and UPV correlated significantly with blood glucose values.

Our results sugges* that albuminuria in children with IDDN is not related to the UNaV and UPV and that rather the metabolic control and some related processes can act together in renal tubular transport of Na and P in very early stagesof renal functional involvement. Departments of Pediatrics, University Budapest I, Hungary, and Freiburg 2, Germany Endothelin 1-21 (E), a peptide with profound vasoconstrictive potential, is produced by endothelial and also by renal epithelial cells, in vitro. Therefore renal excretion may reflect intrarenal (epithelial cell?) production. We measured the renal excretion of E in i0 children with diabetes during severe ketoacidosis (group la) and after recovery 12 days later with normal blood pH and glucose serum concentrations (group ib) and compared it with 15 diabetic children in stable condition (group 2). In addition we determined the influence of exercise on the E-excretion in Ii diabetic children before and after ergometric exercise with I00 watts (group 3 a+b, respectively). During ketoacidosis endothelin excretion is unaltered but E/creatinine ratio is significantly enhanced associated with a significantly lower GFR. In addition to proximal tubular dysfunction this elevation may be a sign Of a disturbed medullary function, probably of interstitial epithelial cells. Ergometric exercise does not change significantly the E secretion, indicating that renal E production is not influenced by elevated sympathic nerve activity. Although inhibition of Na+-K § ATPase activity has been implicated in tissue malfunction in diabetes mellitus the role of other cell ATPases has not been explored.

The current study tested the effect of high glucose/insulin-free medium on several concurrently measured ATPases in LLC-PK I cells with proximal tubular epithelial cell characteristics. As compared to low glucose (LG) or osmolality-balanced LG + 3-Omethylglucose (LG/MG) controls, 48-hr incubation in high glucose (HG) was associated with a 42% (p < 0.001) inhibition in Na+-K*ATPase activity. Quantitatively, however, H+-ATPase activity comprised the major fraction of total ATPase activity and HG-induced inhibition of such activity paralleled the alterations in Na+-K § ATPase.

Basal K+-ATPase activity was low and was unaffected by HG.

HG-induced regulation of ATPases was substantially modified by amiloride, myoinositol, and agents that mediate cell signals which influence transporter function, glucose utilization and cell pH. These data suggest that H+-ATPase inhibition may be due to sustained hypermetabolism of glucose leading to metabolic acidosis rather than by osmolality changes induced by HG. In marked contrast the effects of HG were largely reversed when incubation was limited to 1-hr. These acute effects are more compatible with osmolality rather than pH-induced activation of existing ATPase molecules which appear not to involve synthesis and membrane incorporation of new transport proteins. These data linked with previous knowledge of ATPase regulation in proximal tubules provide compelling but indirect evidence suggesting that cell pH and osmolality abnormalities induced by HG exert significant and time-dependent regulatory effects on multiple ATPases.

It is speculated that such ATPase alterations associated with glucotoxicity are complex and interdependent; that pharmacological modification of such alterations is possible; and that LLC-PK I may serve as a model for the in vitro investigation of diabetic renal disease. We present a study of 32 children (26 females and 6 males) with SLE and renal involvement diagnosed at 3 to 14 years of age with mean disease duradon of 33 months. Clinical, laboratory & renal histologic finding were analyzed. Edema systemic hypertension and macroscopic hematuria were present in 50% of the children. The laboratory ahemations included: abnormal urinary sediment in 97% of the cases, 24 h protein excretion altered in 69.5%, decreased crealiuine clearance in 62.5%, decreased serum complement levels: CH50 -87.5%, C3-81%, C4-54% and increased serum anti-nDNA antibody levels in 94%. Renal biopsy was performed .in 3i children and the histopathologic lesions showed: mesangial glomerulonephritls 35.5%, focal glomerulonephritis 29%, diffuse glomerulonephrids 25.8% and membranous glomerulonephrltis 9.7%. Renal biopsies were repeated in 7 children after 12-24 months: 2 children remained in the same hlstologie class, 5 evolved to other laistologic dasses.

The outcome of the 32 children revealed that: 20 (65.5%) are ha clinical and laboratory remission and still receiving medication: 5 (16%) were lost to follow-up, and" 7 (22%) died (4 from sepsis and 3 from renal failure). It is concluded that renal involvement of SLE in childhood is early and has a high incidence. Urinalysis is very important showing renal involvement even in children without clinical manifestations of renal disease.

The prognosis is related with the type and progression of nephritis; all patients who died of renal failure in the present study demonstrated proliferative glomerulonephritls at the time of their biopsy or at the post mortem examinations. Infeetion and renal failure were the main causes of death. Reduction in the negative charge of the glomeruler capillary wall /GC'J/ has been claimed to account for proteinuria in NS. Theoretically this reduction can be effected by oxidation of negatively charged compounds of GCWo ;~e have shown that there is relationship between antioxldants level and extent of protelnurla in steroid responsive nephrotic syndrome /SRNS//Pediatr Nephrol 1988,2, C148/. ,ie assume that stimulated leukocytes -by generating free radicals known to be strong oxidante -offer plausible explanation for widespread reduction of negative charge of membranes in NS. The aim of present etudy ,vas to examine phagocytic activity of leukocytee including their ability to produce oxygen burst in the course of SRNS.Fifteen children ~vith SRNS ,vere investigated in relapse, during prednisone administration and in remiss~ion after prednisone withdrawal. Phagocytic activity of leukocytes in blood toward Staph P 209 was expressed as percentage of phagocytoslng leukocytes ~L/ and number of phagocytosed Staph per leukocyte /phagocytic i~dex -PI/. Oxygen dependent mete, bolism of leukocytes was measured by chemiluminescence /CL/ resulting from addition of latex particles to blood at the presence of luminol. All measured paramenters ~L,PI,CL/ ,~ere decreased throughout study, only CL value temporarily normalized at the time of disappearance of proteinuria. It is concluded that depressed phagocytic activity of leukocytes in S,RNS may reflect their functional exhaustion but other possible explanations are considered.

TUBULAR .PROTEINURIA IN CHILDHOOD N~PHROTIC SYNDROME. Childhood nephrotic syndrome is characterised by leakage.of protein, particularly albumin, through the glomerulus causmg heavy proteinuria. Proteinuria can also result from tubular dysfunction, characterised by the excretion of low molecular weight proteins. In order to assess possible tubular dysfunction in childhood nephrotic syndrome, we have measured retinol binding protein (RBP)/creatinine and albumin/ creatinine ratios in patient's urine during remission, relapse and when albumin infusions were given for hypovolaemia.

The results are shown in the Whilst no significant increase in RaP excretion ,was found in remission or simple relapse, a large increase occurred during 50% of the infusions (group B). This was associated with higher levels of albuminuria compared with group A, although this is not statistically significant due to the small numbers involved. The rise in RBP excretion was a short-lived phenomenon, despite more persistent albuminuria. We postulate that during albumin infusions a high concentration of albumin in the proximal tubular fluid may inhibit tubular reabsorption of RBP. Albuminuria achieved similar levels on two occassions in group A to those in group B without provoking high urine levels of RBP. The relationship between albuminuria and RBP excretion is therefore not a simple one, and it is possibile that some other factor associated with albumin infusion may have a role. We have studied the bone mineral content (BMC) of the lumbar spine in 29 children (9 girls) treated with corticosteroid therapy over a long period, using dual photon absorptiometry. The BMC was measured by SOPHOS L XRA densitometer which uses 153 gadolinium as the radiation source, and was compared with the values of BMC measured on normal children by a Hologic QDR-1000 densitometer which uses an X ray tube as the radiation source*.The children's average age was 7,1 yrs (2,7 to 15,8 yrs) and the average duration of the treatment, was 3,4 yrs (0,5 to 13 yrs). All the children had a normal GFR and received daily oral supplements of calcium (400 mg/day) and Vit.D (600 IU/day). The mean height standard deviation score for chronological age (h SDS) was -0,52 (-2,8 to 2). The bone age was significantly lower than the chronological age (6,5 vs 7,2; p=0,O01) . There was a positive correlation between the BMC and the age as well as between the BMC and the bone age as in normal children. The mean of the standard deviation score of the BMC was -0,48 for the boys and 0,21 for the girls (p=0,002). There was no correlation between the BMC and the length of the corticosteroid therapy.The values of the BMC were normal except in four prepubertal boys presenting growth retardation. This work demonstrates that the BMC is not modified by a prolonged corticosteroid therapy associated with calcium and vitamin D supplements. The need for treating with calcium and vitamine D is debatable in such cases. *C GLASTRE, P BRAILLON, L DAVID, P COCHAT, PJ MEUNIER, P D DELMAS. JCEM 1990, 70 ; 1330-33 Although 8 weeks initial prednisone treatment recommended by ISKDC is nearly genera~ly accepted, the optimal period of cortiootherapy is still under discussion. It is also supposed that subsequent adrenocortieal suppression is responsible for early relapses. The aims of the study are: i. To compare the results of 2, 5 and E months initial treatment periods. 2. To correlate the results with adrenooortical function.

The study was performed in lit children observed from 1980 to 1990 in which treatment results in relation to its duration were analysed retrospectively, and 67 children treated during last 2 years in which results were analysed in correlation with adrenocortical function determined by 2h Synacthee test performed before and 2 weeks after treatment cessation. In the first group best results (highest percentage relapsefree children, longest medial remission period, lowest mean relapse rate) were noted after 6 months treatment, while results after 2 and 5 m. were significantly worse. In the second group treatment results were similar= percentage of longer remission highest and early relapses lowest after 6 m. treatment. The plasma cortisol level was normal in 95,5% of children before and in 83,6% after prednisone treatment. The Synacthen test showed normal plasma cortisol response in 89,6% and 92,5% respectively. No correlation between adrenocortical suppression and early relapses were observed. We concluded that 6 months initial treatment should be recommended for steroid sensitive NS. Our results does not support the observation that adrenocortical suppression increases the risk of early relapse.

SERUM SOLUBLE CD4 AND Cg8 LEVELS IN PATIENTS NITH NEPBROTIC SYNDROME Y.0htomo*, LFukuda. S. Furukawa and R.Yabuta Dept.or Pediatr., Juntendo University School of Hedicine, Tokyo 113, Japan Recent studies reveal that the levels or soluble CD4 (sCD4) and sC08 in serum correlate with the T cell subset activation. He have measured these levels of 19 patients with nephrotic syndrome who had ~teroid therapy (11 with steroid-sensiti~;e cases ;8 with steroid-dependent/resistant cases) at either the onset of the disease or the relapsing stage. [hese concentrat ions in serum were determined using CELLFREE CD4 and T8 test,kits (T .cell Sciences,Cambridge,HA), and the measurements were done before and after the therapy. Serum sCg8 levels before therapy were significantly higher than normal age-matched controls and these returned to normal range after therapy especially in steroid sensitive cases (figure). have respectively nephrotic and non nephrotic range proteinuria. The most frequent infectious complication was pneumonia followed by peritonitis.The most frequently isolated etiological agent was S.Dneumoniae.cyclophosphamide was chosen as cytotoxic agent in most cases and was successful in 48/98 pts(48.9%).In conclusion: 10.3% of our patients developed loss of renal function;persistent or acquired steroid resistance ocurred in 100% of the children who went into CRF/ESRD;the histological pattern of the biopsied kidney was not a good prognosticator of renal function loss in our pts. Proteinuria in adriamycin nephrosis (AN) is partly mediated by increased thromboxane (Tx) production. Since adriamycin (ADR) is a free radical (FR) stimulant, we administered dimethylthiourea (DMTU), a FR scavenger and stimulator of renal glutathione (GSH), with fish oil (FO). which reduces Tx, to see if they are synergistically protective in rats with AN. In the first experiment, male Sprague-Dawley (S-D) rats (200 gms) received ADR+corn oil (CO) (Group i) or ADR+DMTU+CO (Group 2) or ADR+DMTU+FO (Group 3). ADR was given as 5 mg/kg IV and DMTU as 750 and 250 mg/kg at 18 and 4 hours pre ADR and 250 mg/kg IP daily.

In a second study, S-D rats (200 gms The aim of the present study was to determine the preventive effect of a-IFN on recurrent HSVI in children with hiS immunosuppressive therapy (IT). Material and Methods: 20 children (11 boys and 9 girls) aged 3-14 with NS --hamaturia were included in our study. Renal biopsy was done in 14 eases: 8 patients (pts) had mesangial proliferative GN and 6 pts -membranoproliferative GN. HSVI was found in all children by tissue cultures or in urine & HSVI antibodi~ -by enzyme immunoassay in blood. 18 pts had I type of HSVI and 2 pts had II type of HSUI. Immunofluorescont staining showed glomerural capillary & interstitial tissue deposition of HSUI I type antigen by polyclonal antibodies in 8 pts. The treatment of the nephrotic syndrome (NS) accompanying recurrent FSGS in pediatric renal transplants (Tx) has been disappointing. Nine children with end stage renal disease (ESRD) due to FSGS received cadaver Txs and had recurrence of the N.S.

Seven had recurrence in the first post-Tx week and 2 had late recurrence 3 or more months after Tx.

Urine protein excretion ranged from 2.7-45 gms/24 hr (mean = 16.75 gm/24 hr.).

Tx biopsy was performed in 7 and showed epithelial cell foot process effacement and absence of rejection.

Eight of the 9 had partial or complete remission of N.S. in response to PE and/or high dose CsA.

Ten double-volume PE treatments were performed in 7 of 9 pts.

In 6 patients, CsA dosage was increased and given thrice daily to achieve whole blood polyclonal 12 hour trough levels of 800-2500 ng/ml.

Prior to treatment the mean serum albumin level was 2.4 gm/dl (range 1. 1-3.4) and this increased to 4.3 gm/dl (2.7-5.1) after therapy. The mean urine total protein/creatinine ratio prior to treatment was 28.2 (4.8-78.9 ) and this fell to 2.9 (0.2-10.6) after treatment.

The mean serum creatinine level was 2.0 mg/dl (0.9-4.7) before therapy and after treatment it stabilized at 1.2 mg/dl (0. 6-2.3) . We conclude that PE and high dose CsA may represent a viable treatment option for the otherwise disastrous recurrence of N.S. in children with ESRD from FSGS. P-IIA,34

Chlldren'$ l.fos~l, Unlv of Heislnld, SF-0r

Helstnkl, Finland Congenltol nephrotlc syndrome of the Finnish type Is characterlsed by Incurable, severe pmtelnuda (30 to 60 g/d) from biRh, and the only therapy Is early renal transplantation at 1.5 y of age. CNF-patisnts slmwed severe lipid disturbances, which tended to I~a~_ during the first year: TOfat-TG was 5.14• at 3 1110 and 8.40-s mmo4/I at 9 rno of age, respectively. The Increase In I"G was greatest In the VLDL pafllciss (2.49+_0.57 at 3 mo and 4.52+2.26 mmo~l at 9 mo), but IDL, LDL and HDL partlclas also contained elgnNicantly more TG. Tofat-C~l ~s 6.395:1.67 at 3 mo and 6,95-+ 1.59 mmol/I at 9 mo of age. The elevation of Chol was mainly attributable to Increases of Chof in TC-,-Hchnd panicles (chylomlcrons, VLDL, IDL). These findings reflect s disturbance of the VLDL4DL-LDL cascade suggesting an impaired lipoprofeln !~ (LPL) furc~ion, The mean LPL biological activity was 13.4-+8.3 at 3 mo and 6.4-+3.5 umol/FFIVml/h at 9 mo compared to 23.2• umo~FA/mFh In controls. The mean LPL mass was 194_+72 at 3 mo and 142~32. ng/ml at 9 mo compared to 245:t40 ng~lll In controls. A strong positive correlation ( r=0.92, p<0.001) with LPL biological activity and Immunomactive mass was seen at 3 and 9 mo in CNF-Infants. To study, whether the lipid disturbances have e~__-~d_ vascular changes, renal arteries were Investigated. When the patients were nephrectomlsed at the mean ageof 13m0, asmallpart of sproxlmal arlerywas removed. 90utof12 patients showed a clear histological pathology: 7/12 had Intlmal thlckenlngs and 2/12 flbroprollferatlve changes. No such pathology was found In 13 age matched controls. Decrease of the anionic charge of the glomeru]ar basement membrane (GBM) and especially the reduced amount of heparan sulphate ptoteoglycan (HSPG) in the lamina rata exlerna (LRE) is considered to be the basic pathogenetb: defect in con, genital nephrotic syndromes (CNS). In the present study the anionic charge of glomeruli was studied in eleven patients with the CNS of the Finnish type (CNF) and in fou'r control subjects with cationic probes or lectiias either in electron mi: croscopy (polyethyleneimine ex rive -perfushm; PEI) or i/t light microscopy (Aleian Blue 8 GX, high iron diamine, colloidal iron, WGA and PNA -leetins). Neuraminidase, heparilinase, mild methytation and nitrous acid treatments ',','ere used to characterize the staining pattern of the polycationic probes used in light microscopy_ The median number of PEl-granules /I000 nm cf GBM was 2% 46 in two control subjects and 37-44 in two CNF-palients. In light microscopy the location of different polycations ann lectin binding sites after various degradation treatments was similar in CNF-patients and controls. In the most sclerotic, enionlike glomeruli the polycationic reactivity was weaker than in controls. In the less seriously damaged glomeruli the mesangial reactivity was more pronounced in nephrotic glomeruli than in control kidneys due most likely to the increased amonnt of mesangial matrix in the CNF kidney glomernli.

In conclusion, the amount of anionic sites in LRE as detected by PEt was comparable to controls, Different pnlycationle stains ~and lectins revealed minor changes in the glomerular anionic 'charge in CNF. These results suggest that CNF may differ from other CNS:s in respect to the pathogenetic mechanisms in-~r The urinary excretion of retinol binding protein and N-Acetyl-B-D-Olucosaminidase, expressed in relation to that of creatinine (URBP/UC, UNAG/UC) was studied in 65 children with MRNS: 28 on cyclosporin A (group A), 22 on prednisolone (group P), 15 off treatment (group O) and 32 normal children (group N) to assess renal tubular function and damage. All patients were in remission and had normal serum creatinine. Geometric mean UNAO/UC was significantly higher in group A (26.5) and group P (37.0) compared to group 0 (16.5) and in all nephrotic groups compared to normals (9.3) . URBP/UC was not increased in any of the groups of children with MRNS. According to whether the urinary albumin to creatinine ratio (UA/UC) was normal or raised (aO.l mg/mg), geometric mean UNAG/UC and URBP/UC were as follows: Endotehlin is a potent vasoconstrictor of the renal vasculature.

It inhibits Na+ reabsorption, induces mitogenesis and contraction of the mesangial ceils, and stimulates their production of eicosanoids. In a retrospective, double-bllnd study, we analyzed with an immunohistochemical technique, the distribution of Et in 19 renal biopsies of 16 children with nephrotic syndrome (NS): 9 steroid responsive and 8 steroid resistant minimal change diseases (MCD), and 2 focal segmental glomerulosclerosis (FSGS). A policlonal antibody anti-human Ete, which cross reacts with Etl and Et3 was utilized. All steroid responsive MCD showed only a weak positivity of the vascular endothelial cells, as normal kidney sections. 6/10 steroid resistant NS showed a more intensive positivity of the vascular endothelidm, and of the tubular and interstitial cells; in 3/10 steroid resistant NS, a positlvity of glomeruli was also revealed. The nephrotic syndrome(NS) in the first year of life is associated with various histopathological lesions and different clinical outcomes.We present the clinical and histopathological features of 15 children (9 male,6 female) who presented with NS during the first year of life.The predominant presenting symptom was edema (15/15pts.),it was evident by 3 months of age in 4O%(6/15)pts.A kidney biopsy was obtained in 80%(12/15)pts.,and revealed minimal change disease(MCD) in 25%(3/12)pts,focel tubular atropby(FTA) in 8%(i/12)pts.,focal segmental glomerular sclerosis(FaGS)in 16% (2/12)pts., diffuse mesangial sclerosis(DMS) in 32%(4/12)pts. and Finnish microcystic disease in 16%(2/12)pts.Nine pts.were treated with prednisone,6 with a good response (I FTA,2 MCD,3 without biopsy) and 3 non-responders(1 MCD,2 DMS).Cyclophosphamide was used in three pts.,for steroid dependent or frequently relapsing NS, producing long term remission in all cases.The renal function at presentation was normal in ll(73%)pts,and compromised in 4(26%)pts. all of whom had DMS,in 1 pt., renal compromise was mild,in the 3 others it was already severe, requiring dialysis therapy.33% (5/15 ApproXimately 50 children with frequent relapsing nephretic syndrome have been treated with cyclosporin A at a small dose between 1.0 and 3.5 mg/kg/day from one to 2.5 years. Cyclosporin A demonstrated a favourable influence on the course of the disease. Remission was achieved in approximately 87.5 % of the cases. The frequency of relapses was significantly reduced during the cyclosporin treatment. The reduced frequency was observed in both minimal change nephrotic syndrome, diffuse mesangial proliferative glemerulonephritis and FGS. Mean daily steroid consumption was significantly reduced during the long term cyclosporin treatment. The mean height velocity was significantly increased during the cyclosporin treatment.

Some of the patients achieved nearly normal height velocity during the treatment. The treatment with cyclosporin revealed a significant elevation of total serum protein and albumin and decrease of total cholesterol in serum. Not only the level of creatinine and BUN but also value of the creatinine clearance was not significantly altered during the cyclosporin treatment.

It is interesting to note that an elevation of serum alkaline phosphatase activity was observed in patients who achieved an increased height velocity. Minor adverse side effects such as hypertrichosis or mild hypertension, were observed in approximately 50 % of cases. There was, however, no severe adverse side effects in patients who have long term treatment with a small dose of cyclosporins.

From the above results we concluded that the long term cyclosporin therapy with a smaller dose can reduce the frequency of relapse and the dosage of steroid, and may cause increase of height velocity, without severe adverse side effects. Angiotensin converting enzyme inhibitor has been shown to limit probeinuria. We evaluated the effects of enalapril on proteinuria and crestinine clearance in !6 children (mean age 11.94 years, r: 3.75 -21.83). Twelve were steroid-resistant nephrotic syndrome: 7 had focal and segmental sclerosis and 5 had focal and global sclerosis in the renal biopsy. Four children had reflux nephropathy with abnormal renal sonograply and abnormal DMSA renal scan. The children were followed during two periods. I) Controlled protein intake for RDA and mild sodium dietary restriction for at least I year, IT) As period I, plus enalapril at a mean dose of 0.!7 mg/kg/daily (r: 0.07 -0.38) during 20.19 months (r: 7 -45). Following enalspril, proteinuria decreased from 150.13 + 37.75 to 17.03 + 5.94 mg/m=/hour (mean § SEM) (P < 0.001) whelm creatinine Elearance was 107.38 § I0.42 before and 100.82 + 11.84 ml/min/ per 1.73 m ~ sfter enaEapril. The average fall ~f proteinurim was 80% (r: 31 -100) Clinical data suggest that enalapril may be an useful therapy in patients with massive proteinuria, ameliorating the complications associated with hypoalbuminemia and decreasing the risks of its possible deleterious effect on the progression of renal disease.- Increased serum concentrations ~f totsi cholestermhr and triQlycerides ,ITS) have been described in children with corticosteroidresponsive syndrome (CSNS) de!ring relapses= Conflicting data have been remitted for HDL-C and apolipoproteins during remission and corticosteroid therapy~ Seventy-one shi!dren with CSNS and 208 healthy children ~ere included in the s~dv Fasting serum samples were obtained for determination of CT~ TG and apelipe-proteins~ Simolteneo~s determination of <,roteinuria;crea~ininur_a ratio (P/C? was performed. Serum CT and TO were determined b? ~n enzymatic method~ serum HDL-C was precipitated from serum kv nhomnhnflnnm~ir MgCi2 acid; ago!ipaproteins AI~ A2~ B~ C2, C3~ were ~_<~,m~.~d . ~adial immunodiffusion with nm!yclonal antibodies. The Student test was used for statistical analysis

The following 9 n C~N_ during relapses serzi,~ conrentraUons of CTr TG and HDL-C were significantly elevated~ corticosteroid therapy prod(~ced an add_Lionel !ncrease n~ merlin !ev~l~ n z ~r T8 and HDL-C; inrrem~e6 serum CT levels were :]bserved i~ remission too~ a poor correlat_on has been observed be~wepn 41 and HDL-C~ Children af~e,:ted hv CRNS may have an increased r(s~ <,f atSerosc!erosis~ Long-term AC-steroid treatment of nephrotic children frequently cause suppression of stature. Unfortunately, there are few data on this suppression. We tried to calculate heightvelocity on nepbrotic children during AC-steroid treatment. From the clinical records of 200 patients (137 boys, 63 girls) treated in our hospitals, we calculated height-velocities in relation to steroid dosage for various groups by sex, age and mode of treatment using the data only when the dosage were fixed and height were measured frequently (interval of 3 to 4 months during steroid-treatment period and 3 to 12 months during steroid-off period. ) Suppression of height-velocities are correlated steroid dosage during every~day treatment. On the contrary, suppression i~ not influenced by steroid dosage during alternate day therapy. In patients with the idiopathic nephrotic syndrome, abnormal thyroid function tests have been reported, however, these patients have normal levels of thyroid stimulating hormone (TSH). By contrast, the congenital nephrofie syndrome (CNS) seems to be associated with a high frequency of hypothyroidism.

We have repeatedly investigated thyroid function in a long term study of 5 patients with CNS; in one case the follow-up has reached 3 years. Our findings document that these infants develop abnormal thyroid ftmetioas. The pituitary-thyroid axis was studied using the thyrotrophin releasing hormone (T1LH) test. Age matched control sera were drawn from euthyroid infants for serum TSH levels (n=22).

Each of the 5 patients showed very low serum levels of T4 (< 1.7 mcg/di) and significantly elevated TSH levels compared to controls (19 miU/ml v 4 miU/ml). Despite relatively high doses of l-thyro~dne, TSH levels were never fully depressed (6-10 miU/ml) and T4 levels remained low (1.1-2.3 mcg/dl). The TRH tests showed an exaggerated response consistent with primary hypothyroidism. The basal levels of TSH increased during follow-up demonstrating the evolving nature of the disease with time. High T3 uptake values (42%) we, re consistent with thyroid binding globulin (TBG) deficiency. Serum TBG levels were significantly below normal. (6-9 }z/el vs > 11 /x/el).

In summary, all 5 infants had hypothyroidism which can be explained by massive urinary loss of TBG. The TRH tests showed a picture typical of primary hypothyroidism. During l-thyro:dne treatment TSH levels fell but T4 values remained low again confirming the combination of TBG deficiency and primary hypothyroidism. It is imperative to investigate the thyroid function in all infants with CNS in order to avoid the neurologic sequence of untreated hypothyroidism. ANP is a peptide hormone with natriuretic/vasodilatory properties produced and secreted by atrial myocytes. The renal effects of the hormone are blunted in patients and in experimental models of nephrotic syndrome (NS). The present study was designed to evaluate the characteristics of renal ANP binding sites in rats with experimental NS induced by adriamycin (ADR) injection (5mg/kg, single dose i.v.). Three weeks after ADR or vehicle injection, urinary protein excretion was higher in ADR treated (226• hr) than in control animals (3~• hr). Groups of ADR treated rats (n=S) and control animals (n=S) were sacrificed by decapitation, their kidneys removed, and glomeruli and renal medullary tissues were isolated. Characterization of two receptor subtypes to ANP was achieved by displacement experiments of bound Z2Sl ANP to glomerular or papillary membranes with ANP(99-126) or des(18-22)ANP (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) , an analogue binding to ANP clearance receptors (ANPc) only. The density of total glomerular binding sites (Bma x) was significantly decreased in ADR vs. control rats (151• vs. 418• fmol/mg prot.p<O.05). This decrease was mainly due to a change in the "biologically active" receptors (66• vs. 115• fmol/mg prot.p<O.05). The Bmax of the total receptors in medullary membranes of ADR and control animals did not differ significantly (46• vs. 79• fmel/mg prot. p=NS). Likewise the dissociation constants (Kd) of the receptors for ANP in glomerular or medullary membranes of ADR and control animals did not differ significantly. The data demonstrate a decrease in the density of ANP receptors in glomeruli of ADR treated rats. Such a decrease may contribute, in part, to the blunted natriuretic response to ANP in ADR induced NS.

P-IIA.46

Initial therapy for primary nephrotie syndrome consists of 60mg/m2/day or 2mg/kg/day given in divided doses for 4 weeks and is repeated for each relapse in most current references. Because 40% or more patients with steroid responsive nephrotle syndrome (SRN8) become frequent relapser or steroid dependent, the steroid toxicity is a significant problem. The need for daily divided doses in inducing remission was based on anecdotal observations that a daily single dose was ineffecfive, but recently one report suggested this effect. Since 1988, 23 primary N8 were treated with daily single morning dose of preduisolone, and 22 of them remitted. Retrospectively we compared the effects of daily single dose (N=22) with daily divided (N=45) in proved 8RNS.

Results: (1) The remission rate in the single dose (SD) group was 95.6% which was not different from 90.0% in the divided dose (DD) group. All relapses remitted (100%) in both groups. (2) Mean response time in SD group was 9.8+5.7 days, which was not different from 11.3+6,9 in the DD group. There was no difference between groups whether NS was initial onset or relapse. (3) The relapse rate in the SD group was 59.1%, lower than 84.4% in DD group. The remission interval until the next relapse was similar in both groups (6.3+4.3 vs 5.6+5.1 months). (4) Side effects such as moon face, hypertension, glucosuria and infection were lower in SD group than in those of the DD group. Percent weight gain in SD group was 1.8+3.4%, significantly lower than 3.5+3.2% in the DD group. CT was performed only on the account of frequently relapsing NS and long lasting therapy. The other two children were examined intentionally immediately after pulse-therapy, cumulative dose 1350 and 1850 rag, and duration of the NS 2 months and 18 days respectively. They had the least degree BA chang~ by CT examination.

According to our observations, the most severe BA v~as found in the patients with severe course of the NS and accompanying complications. The severity of the Brain Atrophy changes did not correlate with cumulative doses and duration of the disease. The significance of the hypospadias relates not only to an often devastating cosmetic appearance but to important functional impairment as well. Combining uroflowmetry with ultrasound residual urine estimations provides a useful noninvasive method of following voiding function and dysfunction. The aim of the present study was to investigate voiding function in hypospadias. 52 boys with Hypospadias Glanular and 25 healthy boys /mean age 9.7 yrs/ were estimated by uroflowmetry and ultrasonography. 39/52 children had not surgical procedure /Group A/, 14/52 pts had had meatotomy /Group B/. After 15 ml/kg of water intake, first micturition /FM/ was done at first sensation to void. The second micturition was done after about 30 minutes of the second sensation to void -Retaining Micturition /RM/. Time of first sensation /TFS/ and second sensation /TSS/ to void, residual urine and 5 uroflow parameters assessed were voiding Time /Tv/, voided Volume /V/, maximal /qm/ and average /qave/ flow rate, Time from onset of flow to maximal flow /Tqm/.Results: TFS was longer in both hypospadias groups and was significant in Group A /p o.ol/. TSS was significantly longer in Group A /p 0.o2/ and in Group B /p o.o5/. VFMWaS higher only in Group A but it wasn't significant. Qave and Om were lower in 4 pts in Group A at both micturitions. They need meatotomy. Qave and Qm were also lower in other 5 pts in Group A and in 1 pt in Group B at RM. They need strict follow-up. Residual urine was found in each groups 9pts in Group A, 2 pts in Group B and 3 pts in control group.

After RM more residual urine was found. The biggest difference was in control group -8/25. These findings suggest that children with hypospadias may have diminished sensation of a filled bladder and about 20~ of them could not empty their bladder completely. Examination of retaining micturition may be better to realise slight anomaly in hypospadias. Is there any connection between hypospadias and bladder dysfunction ? P-IIA.48

In the past decade, the increasing use of ultrasound (US) examination caused radinal ehunges in the detection of renal malformations (RM). Over six years (1986) (1987) (1988) (1989) (1990) (1991) 391 patients (pts) with RaM were detected in our institute: Group A contains 102 patients in the years 1986-1988, and group B, 289 pts between 1989-1991. 208 /391 pts were recognized when they were ill and 183/391 by screening. To represent the changes during this period we have compared the two groups. In Group A 28/102 were detected prenatally. While the yearly number of the RM detected prenatally did not increase in 1st period (8-10 pts/yr), we introduced in 1989 a postnatal screening program performed in the 1st month of life. Among the 289 pts, 124 were detected postaatally, 31 prenatally and 134 at illness.

Only 40 babies of the postnataliy detected 124 pts required a thorough nephro-urological work-up. The 84/124 were followed up only by US, because they had mild to moderate urinary tract dilation & in 44/84 the dilation disappeared. The increasing number of pts made us use non invaslve methods to work-up obstructive uropathies. Introducing the Diuretic US we could reduce the frequancy of IVP from 68% to 25% comparing the two groups. The type and time of urological intervention also changed during this period. The number of nephrectomias decreased from 7/28 (group A) to 1i71 (group B). The number of kidney-preserving operations increased (5/28-16/71). The mean age of pts at 1st operation was 9.7 months in Group A and 7 months in Group B. Aim: We wished to determine the significance of "minimal" fetal renal pelvic dilatation (defined as 3-10mm AP diameter) and in particular to determine the incidence of vesicoureteric reflux (VUR). Methods: Fetuses with miminal pelvic dilatation at gestational ages >30 weeks were identified at antenatal ultrasound (US) examination.

Postnatal investigations included renal US and voiding cystourethrography (VCU) at a post-gestational age > 1 week (median 3 weeks). Results: Of 18 babies that have completed the protocol, 2 had normal postnatal investigations. 11 had continuing minimal dilatation with normal VCU; 7 of the latter have had repeat US 3 months later and all had persistent minimal dilatation. 1 baby had significant pelviureteric junction obstruction requiring surgery.

4 had dilatation on US and significant VUR (viz: unilateral grade 3, bilateral grade 4, bilateral grade 5 and grade 2 and 4 on either side). Conclusion: The study is still in progress. The significance of continuing minimal pelvic dilatation without VUR is unknown and the natural history remains to be elucidated. It has been generally stated that "minimal" fetal renal pelvic dilatation is physiological.However,the finding of significant VUR in 4 of 18 babies (22%) and PUJ obstruction in one strongly indicates that this finding requires postnatal investigation. Fifteen infants with asymptomatie unilateral obstructive hydronephrosis were diagnosed and operated at our clinic 1988-1991. The diagnosis was suggested prenatally by ultrasound and confirmed postnatally by IVP and renography under intravenous fluid provocation, combined with Furosemid. The bladder was drained through a transureteral catheter during the examination. The individual renal function was measured according to Piepsz and using inulin clearance or formula. The obstruction was graded according to parenchymal function time and to half time after Furosemid injection.

At the operation significant obstruction was found in all cases and an Anderson-Hynes pyeloplasty was performed.Ata follow-up at {-1 year after the operation the obstruction had disappeared in 14/15 cases and all the children were in good health. The kidney function was somewhat, although not significantly increased.

Fifteen infants with non-obstructive hydronephrosis were diagnosed during the same period and have not been operated. None of them have got a decreased kidney function. A longtime follow-up of these children is continued. Between 1983 and 1991, 23 infectionless and symptomless children (19 male, 4 female) affected with 1II, IV and V degree' veseicoureteral reflux underwent surgery ranging in age between 13 days and 18 months (12 of 23 cases before 120 days of life).

All cases were detected in utero (26-39 week of gestational age). In all cases a Cohan's operation was performed.

15 of the 23 patients had a complete follow-up, so far (cystourethrogram, sonogram and clinical) ranging between 1 and 8 years.

In 13 of the 15 investigated ekUdren 20 urinary tract units (90.9%) did not show any reflux at cystography. In two cases (2 urinary tract units (91.1%) a persistent reflux was seen.

In 11 cases (17 urinary tract units, 77.3%) no LIT dilation were seen at sonography. 22 .&%) the dilation did not improve after surgery. None of them showed an increased dilation. 6 kidneys were hypotrophic on US before and after early surgery. In none of them a urinary tract infection occurred after birth and before the operation. No immediate postoperative complications oeeured. 1). Early surgery is reasonable feasible. 2). Severe damage can occur in the kidney affected for sterile reflux. P-IIA.52

A~Matsui*. T. Takenaka** r M.Hayashi*** I H.Yamanaka***.

Dept. Pediat*., and Obstet & Gynecol**.,Isesaki Municipal Hospital, Isesaki, Gunma, Japan, 372. Dept. Urol**~, Gunma University School of Medicine, Maebashi,Gunma Japan, 371.

Ultrasound examination of kidney and urinary tract was performed on day 2 -5 after birth on 1,753 newborn infants born at Isesaki Municipal Hospital from October 1988 to October 1991. All scans were performed using an Aloka SSD 650 ultrasonic scanning system with 5.0 MHz linear transducer. Infants were scanned in the prone position in 2 planes: along the long axis of each kidney and then perpendicular to this plane. The bladder was scanned in the supine position. Following to ultrasound screening of kidney and urinary tract abnormalities, maximal anteroposterior and longitudinal diameters of each kidney as well as anteroposterior diameter of renal pelvis were measured. Out of 1,753, 21 newborn infants(l.2%) revealed kidney and urinary tract abnormalities. Vesicoureteral reflux was found in 8 infants, hydronephrosis in 6, unilateral multicystic kidney in 4,duplicated ureters in 2, and simple solitary cyst in i.

In addition, adrenal hemorrhage was found in 3 infants and neuroblastoma in i. Mean • SD of anteroposterior and longitudinal diameter of kidney and anteroposterior diameter of renal pelvis of newborn infants was 2.28 • 0.206 cm 4.34 • 0.289 cm, and 0.17 • 0.095 cm, respectively. In conclusion ultrasound screening may be useful for early detection of silent kidney and urinary tract abnormalities in newborn infants. ]~ ~ ~ ltr162 Saul P. Greenfield, M.D., Margaret Fera, R.N. and Christopher Kopp, Buffalo, NY Twenty neonates (9-males, ll-females)with myelodysplasia were evaluated in infancy with uredynamic study, contrast voiding cystourethrograms (VCUG) and renal ultrasound (USG) at a month of age or less. Ten infants (50%) had abnormal VCUG's: six vesicoureteral reflux (VUR) and four with bladder trabeculation alone. Only two had abnormal ultrasounds--both with hydronephrosis secondary to VUR. High leak point pressures (LPP) were seen in nine of 20 infants (45%) and detrusor sphincter dyssynergia (DSD) was seen in seven infants (35%). Of the nine babies with elevated LPP's, seven had abnormal VCUG's and of the seven children with DSD, five had abnormal VCUG's. Conversely, of the ten infants with abnormal VCUG's, eight had abnormal urodynamics: I-DSD alone, 3-elevated LPP alone, 4-both. Two infants with VUR (Grade III and Grade IV respectively) had low pressure bladders withouut DSD. Significantly, all four infants with trabeculation alone had abnormal uredynamic findings. All neonates with VUR were immediately started on antibiotic prophylaxis and five (3 boys, 2 girls) were begun on regimens of intermittent catheterization and anticholinergics.

In conclusion, contrast VCUG in infancy is essential for the discovery of VUR and bladder trabeculation secondary to neurogenic bladder dysfunction in-utero. Ultrasound alone fails to detect the majority of these abnormalities. There is a high correlation between an abnormal VCUG and abnormal urodynamic findings, but VUR can exist without these urodynamic abnormalities. Early comprehensive evaluation enables one to initiate the appropriate medical regimens in the neonatal period. P-IIA. 55

A uniform method of grading hydronephrosis (HN) and the ttretcral dilation (UD) or hydroureteronephrosis (HUN) is necessary in order to more objectively follow the natural history of hydronephrosis detected prenatally. We used the criteria suggested by the Society for Fetal Urology (May 1989) to grade FIN and LTD. The grading method will be presented. We evaluated 103 infants (73 boys, 30 girls) who presented before 1 year old for FIN (76) or HUN (27) . For cases of HN obstruction was diagnosed in 56 (74%) involving 61 (3%) of 97 dilated kidneys. In dilated kidneys with obstructed HN, the mean grade of HN was 3.4+7 (s.d); while in dilated kidneys without obstructed FIN the mean grade of HN was 1.6-+8 (9< .05). When the value to predict obstruction is set at HN Gr > 3, there was 88% sensitivity and 95% specificity. For cases of HUN, obstruction was diagnosed in 15 (56%) involving 17 (50%) of 34 dilated renal units. When the degree of dilation is examined as a score, HUN score = Gr HN+Gr UD, the best correlation of dilation with obstruction was noted. In cases of non obstructed HUN, the average HUN score was 5.8_+1.9 (p<.00l). When the value to predict obstruction is set at HUN score ~5, there was 94% sensidvlty and 80% specificity. Although ezami,atious of ultrasound images cannot be used to diagnose nephroureteral obstruction, the diagnosis of obstruction is linked with the grade of HN or score of HUN. Retrograde ureterography is commonly performed just prior to pyeloplasty in cases of uretero-pelvic junction obstruction (UPJO). A total of 103 patients were operated on at our institution for UPJO over an Ii year period (1979 Ii year period ( -1990 . Ninety-seven records were available for review. The objective of our review was to determine if retrograde ureterography uncovered any significant secondary findings. Thirty six patients did not have pre-operative retrogrades. In 17 of these patients the ureters were visualized preoperatively by other radiographic techniques (IVP-3; antegrade study-8; VCU-6). Nineteen patients did not have retrogrades performed for technical reasons. There remained 61 patients in whom 66 retrograde ureterograms were performed immediately prior to surgery (5 patients had bilateral studies). In 65 of the 66 UPJOs, the findings on retrograde ureterography did not alter the surgical approach. An upper tract procedure was performed as initially planned on 63 renal units (54 dismembered pyeloplasties; 6 ureterocalycostomies; 2 nephrectomies; 1Culp pyeloplasty). Two patients with bilateral UPJOs had retrogrades performed on the less affected side although repair was not undertaken. Based on this review, the routine performance of preoperative retrograde ureterography for UPJO may not be indicated.

There is much controversy regarding the optimal initial surgery for advanced stage Wilms tumor, primarily , because of the success of chemotherapy.

We present an unusual complication of surgical treatment of a large tumor that was ultimately sent to us for further management.

This case involved inadvertent resections of the subhepafic inferior vana cava and ligafion of the remaining renal vein leading to renal insufficiency and anuria. Repaid included de-clotting followed by a renal vein to portal vein bypass. One year later, the serum crcatinlne is normal and she has no evidence of metastases.

This case will be contrasted with other cases where biopsy and chemotherapy rather than initial extirpation were performed in an mlnlmiTe surgical morbidity. Only two patients reported spontaneous normal erections.

All others had a poor quality or absence of erection.

Follicle-stimulating hormone and. luteinizing hormone were elevated in 55% (5/9).

Total testosterone was low in 44% (4/9).

Prolactin was normal. Several patients attempted masturbation, vibratory stimulation, and rectal probe ejaculatory stimulation for semen specimens. Semen was obtained from only one patient and it showed azoospermia.

We conclude that postpubertal patients with myslodysplasia exhibit a high incidence of primary testicular failure afflicting both the spermatogenic and androgenic axis.

This preliminary physical, endocrinologic, and radiologie data portend a poor prognosis regarding fertility status of males with myelodysplasia. The etiology of this defect is unclear. Reviewing the pre-operative i.v.urograms of the obstructive megaureters in which there was a persisting dilatation after surgery, we observed that ureters ended in a distal position and that the dilatation ended abruptly right at the level of the bladder wall .

In the last two years we performed careful pre-operative endoscopies in patients affected by megaureters . Eight out of 28 in this period had caudally eetopic meatuses within the trigone, almost without a submucosal tract . When bilateral, the more dilated ureter had the more caudal ending .

We used in all patients the Cohen plus tayloring technique .

In eetopic ureters the muscular hiatus was moved cranially and laterally simply by proximally cutting the muscular wall and suturing it distally . We believe that these ectopic ureters were obstructed in their terminal tract by the surrounding muscular fibers of the bladder wall, which, in the trigonal region, are in tonic contraction for continence .

These ectopies seem to be more frequent than normally thought Prenatal' diagnoses of renal structUre pathology was made in 93 fetuses (58 male, 35 female). Of the 81 infants born (there were 10 TOPs and 2 still births) 58 were born to parents living in the departemeat. The annual incidence of renal abnormalities was 2.8 per 10,000 live births.

48% of the diagnoses were made before ~'eek 30 of gestation and 28% after week 35. Of the 25 fetal caryotypes, 2 were abnormal. The more frequent abnormalities were hydronephrosis (48% of the babies), mega-ureter with or without duplication (19%) and multicystic dysplasia (16%). The pre and postnatal diagnoses were in good agreement in 82% of the cases.

Of the 56 infants with obstructive uropathies followed up after birth, 17 underwent a pyeloplasty within 3 months of life, 32 had conservative treatment of whom 7 were lost to follow-up and 4 were operated on afterwards. Of the 7 who had normal ultrasound scan at birth, 3 had abnormal scan during the follow up. In none of the 11 cases of mulficystic dysplasia followed after birth was aephreetomy performed : 1 patient was lost to follow-up, 3 had stable lesions and in 7 the cysts decreased in size or disappeared. Renal abnormalities always present nonspecific symptoms or a~ silen~., especially among children, and it is difficult to detect an abnormality by routine urinalysis. We report the results of ultrasonographic screening to determine the prevalence of renal abnormalities in children. This study was conducted simultaneously with a regular health check using portable real time ultrasound equipment(ALOKA, SSD-21-DX), from 3uly 1978 through November 1991. 7725 three-year-old children were screened in Kurume City. The probe using a 5MHz transducer was placed on the back region and both kidneys were screened quickly, with each examination requiring 20 to 30 seconds. ABnormalities were detected in 35 of these, involving 19 cases of pelvic dilatation, 8 cases of unilateral renal agenesis, and 3 ca~es of a unilateraly small kidney. However, the simultaneous urinalysis a%n 3# of these 35 children did not disclose ar abnormalities. In all children, renal function revealed no abnormalities. Our results indicate that ultrasonography is an efficient tool to screen for silent renal abnormality, Long-term follow-up studies are needed to clarify the natural histor.~ of those found to have an early abnormality.

.Naylr*~A.Kadlo~lu~A.$irin,S.Emre,F.Tanman~E.Erim,C.Bayram Istanbul University School of Medicine ,~apa,Istanbul, 39390,Turkey.

The aim of thisstudy is to determine the specifity and sensitivity of ultrasonography(US) in detection el renal pathology for children with meningomye-locele (MM).We offer a protocol for US during first year of life. Between January 1990 and June 1991 67 These were confirmed post-natally. Prenatal morphometric measurements were done in order to find parameters that could detect a group at risk for surgical treatment. A second aim of the study was to describe the natural history and management of hydronephrosis detected prenatally. We devised a classifiction of obstructive uropathy using ultrasonography and the DTPA scan. Accordingly, we classified the patients as having mild, moderate or sever~ hydronephrosis.

A pelvic volume of 0.69 cm 3 before 32 weeks of gestation and 1.5 cm thereafter, and a pelvic to renal volume ratio of greater than 0.08, can be used as thresholds for the detection of an infant with an unfavorable outcome. In addition, a pelvic AP diameter of 9 mm or more, and a pelvic to renal AP diameter ratio of 0.45 before 32 weeks of gestation and o.52 thereafter, were also useful.

Nine patients had pyeloplasties and five had ureteric reimplantations. We conclude that in most cases, there is no need for immediate surgery, and that the initial approach to the management of congenital hydronephrosis should be conservative.

T~te prevalence of primary VUR in portuguese children was evaluated by an enquiry distributed to the Paediatric Nephrology Units. From an overall population of 2030600 children under 15 years of age, reflux was reported in 822 patients and classified as primary VUR in 662 (67%). Data on sex, age of diagnosis, clinical presentation, degree of VUR and scarring at presentation, management and outcome, were obtained. There was a female predominance in all the age groups studied with the exception of the first year of life where the number of males was higher. Bilateral reflux was present in 50% of the eases and the number with mild, moderate and severe VUR was similar in all age groups. Renal scarring, on DMSA, was initially present in 176/492 (58,6%) patients. Of these, 18/176 (10%) were hypertensive and 28/176 (16%) had impaired renal function. These complications correlated with the degree of scarring and age of diagnosis. Only 20% of the patients reported underwent surgical treatment, which was performed mainly in subjects with severe reflux and recurrent urinary infections. New renal scars as well as breakthrough infections and new cases of hypertension and reduced renal function were observed in both medical and surgical treatments, at the latest follow up. Due to a number of reasons this study probably underestimates the real prevalence of VUR in the Country. However it is useful as a baseline for a planned national prospective study, on this condition. Aim : To assess the observe(i cc~lience, knowledge and attitude of the patients and parents currently at-tending the paediatric transplantatian follow up clinic. Patients and Methods : A questia~naire designed to evaluate general charantsristics, confirm cc~Dliance, explore atti~ades and knowledge ~s administered to 56 transplant (TP) patiente and theL-parents. Patients have previously been divided into non compliant (NC), doubtful (D) ~nd co~pliant (C) ~oups based on (i) admission of not -=~ medicatian (if) admit medication hasinished (iii) missed clinic visit such Chat medication would have been insufficient (iv) COrLeirmed by retrospective CyA analysis. Statistics : are reported as means + standard deviation. All values are t~o tailed. Data was evaluetsd using cbi squared, Fisher e• end one "nay analysis of variance. Significence was set at P < 0,05. Results : Fif~] six current TP attenders .,ere assessed, C 33, D ii and NC 12 patients. Aze ranges were similar. More NC patients were males, C 20/33, 517 11/12 ; p = 0,0352. NC patients had more TP's, p < 0,(95 for Srd ~Y~afts, missed their clinic apgoinuren.ts C (6%) vs NC (SCP/o) p = 0,0026, ard forgot to take lJleir medicines more often t~n C patients, C (Z ~) .s NC (50%) p < 0,05. Fedication side effects troubled 9% of patients. Dispensary labelling and explanations were poor, 25% and S(F/~ respectively. C patients take less medication (i) C 7,5 f 2,0 ms NC I0,0 + 3 ~end remember the number (if) C 7 + 2,0 vs NC 8 + 3,5, and more of the dr~ names (iii) C 6,5 + 2,5 vs NC 4,0 + 3,5, than NC patients. NC patients know very few of the drug r~mes C vs NC p = 0,0001 and are asable to recall how msny dr~ they are tending; C 7,5 + 18% vs NC 21,8 +-2~/o forgotten. Parent and patient knowlec~e was poor; of C 7~o vs NC 2EP/~ correctly identified thein ~m~mosuppressives p = 0,0057; 4s don't know alternative drug names; i~/o thought tb~t they could stop 9munosupprsssives. Only 41% new their original illness; C 5a, [F/~ vs NC 8, ~/o, p = 0, 0198 , and only 45,5~/~ knew why they needed a TP. Eighty five percent would like more ongoing teaching post TP. Conclusic~s : The major areas in Paedialric Transplantation needing intermention have been identified. A pre-traesplant ccmpliahce contract, ec~ tien strategies, medication checks and an angoing surveillance pro~ have been instituted. P-IIA.65

From the complete separation of the nee urinary bladder to the digestive tract, by the own change of Heitz-Boyer-Hoelasgue method, made in 1966, the authors operated thirty children with extrophy of urinary bladder by this method.

All children were checked after six months and then after one year by laboratory tests, urography, micturition eystography and in ease of need by renal seintigram, and by ultrasound.

With the exception of three children who were found with utero hydronephrosis due to the stanosis of ureter-rectal implantation, a stenosls whlch was accompanied by the urinary infection -one case, bit hiassis, another and the last case by the functional dumb kidney, in the other cases laboratory test and the urography were in normal limits. After a period of adaptation between six months and one year after the operation the children felt well, the urines were sterile, the urographles were normal, all these prove the using of this method.

To prove all these the authors will present a film. Failure of growth is a frequent feature after RT. D is an oxazs line compound derived from prednisolone with a similar antiinflammatory action but fewer side effects. We studied changes in kidney function, growth velocity(GV),weight for heightratio (Wt/Ht), thyroid function, before and two years after substitution of methylprednisone(MP) by D in l0 patients aged 9 to 16 years, 4 years after RT; 8 were in Tanner stage I and 2in Tanner IV. In 3 patients, immunosuppressive treatment includ~ azathioprine and MP while in the other 7, a triple therapy including cyclosporine, was used. MP (6 + 0.3 mg/day) (x + SEM) it was replaced by D (9.6 ! 0.5 mg/day~for a period of 2years. Serum creatinine (Cr) and Cr clearance did not show any signif leant changes before and during D treatment, 1.22+ 0.i vs 1.3 + 0.2 mg/dl, and 69 + 8 vs 73 + ii ml/min/l.73 m ,respectively In 8 Tanner I patients, GV increased from 1.7 + 0.4 to 4.1 + 0.8 cm/yr (p<0.005); 4 of them reached GV>4 cm/yr. Wt/Ht decreased from 27 + 7 to 21 ! 7% (p<0.02)~ean concentrations of total thyroxine-(T4) (8.6 ! 0.4 ug/dl),total triiodothyron ! ne (T3) (1.7 + 0.2 ng/ml)and basal thyroid-stimulating hormone (TSH) (3.1 + O.2 mU/L) were normal,while mean free T4 level (I.i ! 0.06-ng/dl) was below the normal control mean (p<0.01). Five patients on MP and 5 on D had deficient TSH response to thyrotropin releasing hormone (TRH).Circadian TSH pattern was studied in i0 patients, 5 on MP and 5 on D therapy. Four out of I0 patients had a nocturnal TSH surge below the normal range (95% confidence limits 47% to 300%). In pediatric patients after RT on D treatment: I) renal function remained stable; 2) Wt/Ht deereased;3)GV increased and 4)thyroid funetion'remained stable. The association of low free T4, deficient TSH response to TRH and impaired nocturnal TSH surge, support the hypothesis that some RT patients on glucocorticeid therapy have central hypothyroidism. Results of renal transplantation (Tx) in children under 5 years of age have been reported to be inferior to those in older children with a mortality of up to 15%, a lower graft survival and. vascular complications in 20%. CMV-infections have been a common complication. We report our experiences with renal Tx in 23 children less than 5 y of age transplanted after 1987. Mean age at Tx was 2.4 y (1.2-4.3y, 10 pts <2y) mean follow-up time was 2.2 y (0.1-4.6 y) and all pts had been at least 3 mo on CCPD prioi to Tx (mean time on CCPD was 9 mo). All pts were transfused prior to Tx and one miss-match in A, B and DR loci was accepted. Mean donor age was 28.7 y (4-40 y) and 11 were LRD:s. All grafm were placed retropefitoneally in the fight iliac fossa, mean cold ischemia-fime was 25.7 h (19.3-39.0 h). Triple immunosuppression was used and CyA started preoperatively at a pharmacokinetically determined individual dose devided into 3 doses/d. Anti-CMV immunoglobulin prophylaxis was given for 3 rno if the donor was CMV+. Patient survival is 100% and graft survival 91%. No vascular complications have been encountered. CMV-infection responding to gancyclovir was seen in,2 pts and led to nephrofic syndrome and chronic rejection in one. Mean serum creatinine concentration is 76 umol/L, mean GFR 68.7 ml/min/1.73m2 and catch-up growth is seen in most pts 6-12 mo after Tx. One lymphocele with stenosis of the urether has been the only urological complication.

We conclude that results of renal "Ix in 1-5 y old children are similar to those of older age groups with the present mode of treamaent. One factor responsible for the better results is presumably the use of kidneys from young adults for young children reducing vascular complications and pre-Tx CCPD which brings the child in a better clinical status to Tx. Tissue-typing, pre-Tx transfusions and tailor-made immunosuppression might be additional factors. Although CMV-infections have been sparse the role of Anti-CMV immunoglobulin is not clear. Over last two years, renal transplantation was perfermed in ten children. Five weighed between I~ te 29 Kg;five weighed between 11 te 15 Kg. Seven were males, three females. Age ranged between 3 and 16 years. Cause ef renal failure was glemerular in six cases <F~S-2, EOS-1, a/KA~-I, Yasculitis-t, SL~-I ), tubuleinterstitial in four cases ~Chrenic interstitJ~l nephritis-l, ~dullary cystic disease-l, Posterior urethral valves-I, ~eflux nephrepathy-1 ). All received at least tl~ree Bleed transfusions Q Donor specific-4, Nen specific-6 ). ~ener was 'mother' in 5 cases, 'father' in 2 cases, living unrelated in 5 cases. Average duratien ef protransplant dialysis was 4 ts 6 weeks ~ Peritoneal dialysis-6, ~emedialysis-4 ). Major preoperative complications included seizures-4, pericardial effusien-1, uncentrelled hypertensien-1. Transperiteneal appreach was used with anastomosis te major bleed vessels, ~ilateral ~ative ~idney ~ephrectemy was perfarmed in 8 cases. ~eur episodes ef rejection were enceuntered ~ two reversed, one resulted in graft less, one chrenic rejection). ~jer cemplicatiens in pest transplant period included seizures-2, A~DS-2, reactivation ef tuberculosis-l, fulmlnant gastreenteritis -I, ~ypertentien was present i~ 90~ cases. One died ef A~DS, two have graft less~1 month e 1 year after transplant;. All ethers have nermal renal functions at 3 months te 2 years after trausplantatien with geed rehabilitatien.hate referrals, passive attitudes, cultural barriers, secie economic status are some ef the factors which influence transplant presrams in deve!eping countries. Exogenous addition of catalase, one of the cellular regulators of free radical oxygen species, has been of limited success in extending the viability threshold of transplanted organs after long hypothermic preservation. We have previously shown that catalase is prone to oxidative injury during ichemiaJrepertusion (Gulati et al. Arch Biochem Biophys 1992 In Press) . To understand the possible mechanism of this limited success, we have studied the effect of cold flush hypoth ~rmic perfusion with EC vs UW preservative solutions on endogenous catalase. The kidneys of Sprague-Dawley rats were flushed in situ with either EC or UW Solution, then surgically removed and preserved at 4~ for various times in each solution. Controls were cold flush perfused only. Kidneys in each group were analyzed morphologically by electronmicrograpy and part homogenized for enzymatic and wete'n blot analysis. Enzymatic activity is reported graphically as percent control. Western blot demonstrated approximately the same levels of catalase at all time intervals for both EC and UW solution. This would indicate that the decrease in catalase activity is due to inactivation rather than degradation. UW has a significant protective effect over EC on catalase activity for 48 hours, however the subsequent deactivation of this enzyme in both solutions may represent the rate limiting factor for its role in oxidative injury. Since february 1989, routine monitoring of a combination of biological markers in serum (O reactive protein, CRP and neopterin/creatinin ratio, N/C) and in urine (micrealbuminuria, Ms) were performed in kidney transplanted children in order to allow early detection and diagnosis of allografts rejection and/or infections. Ma, CRP and N/C were determinated each third day on hospitalized patients and at every outpatient visit there-after. Ma (normals lower than 50mg/l or 20mg/day) and CBP (normal$ lower than lOmg/l) were measured by immunonephelemetric method. N was determined by radioimmunological assay and N/C ratio was used in order to dissociate raised serum neopterin levels caused by impaired renal function from elevations due to activated cellular immunity (monocytes/macrophages exposed to interferon). Patients (N=42) were divided into 5 groups according to infection (bacterial or viral), siclosporine overdosage (whole blood determination, BIA polyclonal, residual level higher than 500mg/ml), non-specific (urinary tract obstruction or reflux, renal arterial stenosis). Children with stability had normal values for Ms, CRP and specially for N/O (117 t 32, N=42 patients, n:1715 prelevemelts). During acute graft rejection (17 episodes), CRP usually remained constant but a dramatic increase occured both for Ma (range : 64 to more than 300mg/l) and for N/C (range : 162 to 340). The highest rise of N/C (range : 253 to 847) without rise of Ma can be correlated with viral infections (C~9] usually).No biological marker taken alone was, in all cases, specific enough but, besides clinical manifestations (clinical evolution) combination of these three biological markers used routinely (biological evolution) may be considered as a useful tool for the follow up of transplanted children. 

Besides the risk of recurrence of proteinuria, the nephrotic syndrome (NS) may be complicated with deep-vein thrombosis. The occurrence of extensive thrombosis of the inferior vena cava (lVC) is a technical obstacle to renal transplantation (T), that can be overcome by using the portal vein for transplant vein anastomosis. Patient 1 is a girl with diffuse mesangial sclerosis. The NS began when she was 9 month-old ; she required dialysis 11 months later and bilateral nephrectomy was performed because of severe arterial hypertension. A first renal T was attempted when she was 5, but it was not achieved because of thrombosis of the IVC, without previous clinical evidence. She was successfully transplanted when she was 6.5 (cadaver, 12 y) since the implantation of the transplant vein was allowed on the portal vein ; the arterial anastomosis used the aorta. There was no major complication during the post-operative period. After a 5 yearfollow-up, the GFR is normal (SCr = 78 p.mol/I) and there is no evidence (biological tests, doppler ultrasound, liver biopsy) of portal hypertension nor hepatic dysfunction. Patient 2 experienced NS related 1o FSGS when she was 1 yr-oid. ESRF required dialysis when she was 4 and bilateral nephrectomy was done when she was 5.5. A first renal T was performed at age 6 ; the presence of a thrombosis involving the whole IVC prompted to use the ovarian vein for graft implantation, but early thrombosis led to transplantectomy. A second T was carried out when she was 6.5 (cadaver, 7 y) ; portal venous drainage and arterial anastomosis were achieved in the same conditions that in pt 1. The postoperative period was complicated with a recurrence of the NS on day 5, that was controlled by plasma exchanges + switch of azathioprine to cyclosphosphamide. 14 months later, the GFR is normal (SCr = 50 #mol,'l) and there is no proteinuria. Doppler imaging, biological tests and biopsy of the liver show no abnormality. In case ol extensive thrombosis of the IVC, when neither the primitive lilac veins nor the supra-rena~ part of the tVC can be used, the implantation of the transplaht vein can be successfully achieved on the portal vein without significant hemodynamic nor functional change of the liver. Our patients had no rejection episode and their current renal function is normal. Portal drainage seems to be the only alternative in such children ; however the difficulty of transplant biopsy and the ability of ureteral lengthening cannot be appraised. Negative nitrogen balances(Nb) have been reported in patientsarter renal transplantation (Tx), p~rticularly in the first post T• period lhls could account for growth impairment described in some tran6planter children. Recombinant human growth hormone (rhGH) is known I.o improve Nb in surgical, burned, infected and hemodialyzed patients There are no data concerning Nb response ]n children with renal T• to r hGH treatment at different protein intakes Three children aged 14.4 to 16 years, with functioning renal T• l~>m 4.3 to 52 years and creatinine clearances between 32.8 and $24 ml/min/1 73 sqm on immunosuppressive (i s.) therapy wilh corticosteroids § cyclosporine A (CSA) (two cases) or with CSA only/erie case), were given rhGH (25 U/mq/week; 5aizen, Serene) because ef impaired growth (HSDS : -2 and HvSDS ", 25th eentite for chronotoqiCa.l age) Nb and urea nitrogen appearance tUNA) were evaluated durir~g Iw,, 20 day-baseline periods on different protein intakes (DPI),(T1 =10,q!E~!)A, T2=lSO%RDA!, followed by two periods (GH-TI; GH-T2) nf rhOH trealrnent on different protein intakes (GH T1 IO0%RDA, GH-T2 = 150%RDA) Calorie intake was maintained between 60 and I O0~RDA The risults can be summarized as foIlows:

Act Co~ t icosterolds (Cs) may decrease linear growth in children wil h rer~l transplantation (T• by a still incompletely known roech;~l,~m Inhibitory effects of Cs on growth hormone (GH) and somatomedir, L ($mC) release have been t~ypothesized GH and SmC level'_; and lin,,aL growth were assessed in children with renal Tx on two diflele~,l immunosuppressive (is.) protocols: group h 7 children with renal Txo~ is therapy with cyclosporine A (CSA) and (Cs); group I1 7 chi Idren w!tb renal Tx treated with CSA alone. The two groups were comparabl~ for chronologic age ( 106 .+ 2 vs. 10, t _+ 2 years; p=ns), bone aqe (tJ8 2.4vs 7_~ 25 years;p=ns), r clearance (69,2_+ 20Av,~, 7z9 • 156 ml/min/1.73 sqm; p=ns),time since Tx (1.6 ~_ 1.2 vs 2,7 : I I years; pens) and CSA dosage (6.7 +_ 21 vs72z I.Tmg/kg/day;p-l,S~ Lineal-growth changes between the time of Tx and the time of hormohal assessment expressed as standard deviation scores for chbonolog~c ~gf.. ( ,~ H5DS) and growtll velocity for chronologic age (HvSDS) m tip y~al before the hormonal evaluation, peak GH levels after clonidine stimutabor, were evaluated. The results can be summarized as follows:

A HSDS HvSD5 GH(mg/n d ) / -0,1 + 0.45 -1.5+ 17 1804+ 13.8 II + 099+0.37 +2.4+_3.2 29.12 +_ 1016 p =0001 =00 t 4 <D() 1 There was a direct correlation between HvSDS and beak GH le..ttls (p=O,O12). SmC. Thyroxin (FT4) and prolactin (PRL) weir meas,, r and were in the normal range.

In conclusion, the significant greater linear growth of h ahspl~(ded chiIdren treated with CSA alone may be partially due to their hiqh.~l Gi't levels, since there were not inhibited by corticosteroid treatment P-IIB. I0 Sixty renal transplantations (tx) were performed in 53 children, 27 boys and 26 girls, less than 16 years of age (median 6.8 yrs; range 5 mos -15.6 yrs) between December 1981 and December 1991.55% of the children were _< 7 yrs and 23% <_.2 yrs. 42 children had congenital nephropadfies, most commonly dysplasia, polycystic kidney disease, juvenile nephronophtisls and congenital nephrosis. 11 children had acquired renal diseases mostly glomerulonephrids. Padents with congenital diseases were transplanted at a significantly lower age (5.9i-0.6 yrsmean +SEM) than those with acquired diseases (10.1+1.4 yrs). 29 children were on dialysis prior to tx (22 on PD, 4 on liD, 3 on both). There were 53 primary transplants, six second and one third tranplant. 42 of the grafts were obtained from living donors (40 parents and 2 grandmothers) and 18 came from cadaveric donors. Immunosuppression consisted of cyclosporine and prednisolone in 13 children. 40 children also received azathioprine. Six patients have died (3 with functioning grafts) and 4 of them were < 2 yrs of age. 12 grafts have been lost (acute or chronic rejection 5, technical failure 3, patient death 3 and recurrence of disease 1). The median height SDS of the children at tx was -2.23 SDS (range -10.0 -1.97 SDS). The median height SDS at 1, 2 and 3 yrs after tx was -1.81, -1.14 and -1.21 S DS respectively. 51% of the children were on antihypertensive treatment before primary tx, 79% during the ftrst year and 30% after 5 yrs. The mean GFRs, measured as clearances of inulin, am presented in Fig. There was no significant change in absolute GFR during follow-up. GFR related to BSA decreased signiticantly from the fifth year specially in cadaveric recipients. In conclusion, most children survive with improved growth and development and with a satisfactory renal function after kidney transplantation. The effectiveness of OKT3 in reversal of steroid resistant rejection has previously been demonstrated in pediatric renal transplant recipients. The purpose of this retrospective analysis was to determine the efficacy and both immunologic and infectious comp, lications seen in a pediatric renal transplant population receiving OKT3 induction. Twenty cadaveric renal transplant patients (mean age 12.5 +4.8 yrs) received 14 days (mean 13.0 -I-2.8 days) of OKT3 (mean dose 0.16 +0.09 mg/kg/dose) along with prednlsone 0.5 mg/kg/day, azathiaprine 2 mg/kg/day and cyclosporine 5 mg/kg/day which was increased to obtain therapeutic levels before the discontinuation of OKT3. Four children had immediate post operative vascular thrombosis, only 1 of which was felt to be technical in origin. Two of the other 3 children had focal segmental glomerulosclerosis but were not nephrotie at the time of transplant. 75% experienced rejection episodes within the first 2 months post transplant (mean 27 +15 days) with 1 patient having a break-through rejection during his OKT3 induction. Actuarial patient and graft survival, excluding the 4 immediate graft losses, were 100 and 62%, respectively, at both 1 and 5 years. Clinically significant cytomegalovirus infection occurred in 4 patients (1 episode occurred after a second course of OKT3) and resulted in graft loss in 2 patients. Circulating OKT3 levels ranging from 1000-32,000 ng/ml were seen in all patients within the first 48 hours. One patient required an increase in OKT3 dose, concomitant with OKT3 antibody formation on day 8. There was a rapid and total depletion of circulating CD3 + lymphocytes in all patients. Antiisotypic and anti-idiotypic OKT3 antibodies were assessed by ELISA and antiidiotypic antibodies were detected by immunofiuorescence inhibition assay. Positive OKT3 antibody titers were, detected in 11/19 children by ELISA and 10/15 children by immunofluorescence inhibition assay. In summary, we have found 1) OKT3 induction therapy is associated with a high incidence of vascular thrombosis, the etiology of which is unclear but deserves further investigation, 2) the incidence of early acute rejection, time to first rejection and long term graft survival does not appear to have been beneficially affected by the use of induction therapy and 3) there is a high incidence of sensitization against OKT3. 

[nivershies of Heidelberg and Erlangen-Niirnberg, Germany Prescho~d children and kidney donors below 6 years of" age are malkable risk factors in pediatric renal transplantation (tx). We studied the influence of donor' amt reuipient age oil tile long-term outcome of the graft. Therefore we artalysed lst) the median creatinine ciearence (CCR) 6 months after transplantation and 2~.1) ti~e change in GFR.'year. Data of grafts functionh~g > 5 months post tx were compared with our standard Ix data (ST) obtained in 115 consecutive grafts (all of ~hem receiving cyclosporine A). At 6 month after' tx 4:10 grafts of donors younger than 8 years of age but 0,9 of those older than 40 }'ears of age presented with an CCR above the median of tile ST. Yearly change in GFR was similar in both groups. Comparing recipients < 7 years of age to those between 13 and 18 years of age, pattern of the GFR at 6 month was similar to ST, wheraes the change ia OFR;year was better than the median of ST in only 39% (102 patient years) in pubertal recipients as compared to 66% (87 patient years) in child~'en younger than 7 years of age. In conclusion: Preschool children and children receiving kidneys from donors < 6 years of age have an excellent outcome when they have passed the first 6 months post tx successfully. 

In patients treated with Cyclosporine A (CYA) differences in GFR and FF were found, no in ERPF. Results after the first year (GFR and ERPF in % of normal values of both kidneys of the R):

with CYA(n=23) without CYA(n=I5) GFR 44+/-11 53+/-20* ERPF 34+/-15 30+/-14 FF 0,249+/-0,08 0,36+/-0,151 (* p<O,05) Functional hypertrophy of grafts is regulated by the R. It takes place despite CYA-therapy. Pseudotumor cerebri manifests as elevated intracranial pressure (ICP) without localizing neurological (CNS) signs. In children, otitis media, corticosteroid withdrawal,obesity and vit A intoxication are some of the causes. PsC is not reported in renal transplant children. Transient visual loss in PsC is reported in 0-30%. A controversy exists about the incidence of permanent loss. We report 2 boys (MC 14yrs, JG 7yrs) developing PsC 5 yrs after cadaveric renal transplantations. In addition to severe headaches, MC complained of intermittent blurred vision while JG was dehydrated due to severe vomiting. Both had elevated BPs(140/104;138/96), papilledema, normal ventricular system on cranial computed tomography (CT) scan with and without contrast, and no evidence of focal CNS changes. On spinal tap, opening eerebrospinal fluid (CSF) pressures were 53; 49em H20. Laboratory examination of CSF was normal. JG required two spinal taps to reduce CSF pressure to normal with resolution of symptoms. In MC, multiple spinal taps reduced CSF pressures temporarily with no improvement in symptoms and required lumboperitoneal shunt to reduce elevated ICP. JG had complete return of vision while MC had partial return of vision. In addition ~o usual immunosuppressive therapies for renal transplantation, both were on small doses of prednisone (MC-5mg,JG-2.5mgOD). Both were suspected to have abruptly stopped prednisone therapy. Both had problems with hyypertension. JG had chronic otitis media (OM) with effusion. MC had hypertensive encephalopathy prior to renal transplantation. A sudden withdrawal of corticosteroids in our pts with additional risk factors such as hypertension and chronic OM may have precipitated PsC. Early diagnosis and aggressive reduction of ICP is required to prevent vision deterioration.

Michigan State University, East Lansing, Michigan,

The effects of omega -3 fatty acids (fish oil) on the lipid abnormalities associated with cyclosporin were investigated in five subjects, four of whom were post renal transplant.

Subjects received five grams of EPA/DCHA for three months. Measurements of triglycerides, total cholesterol, HDL, LDL, VLDcholesterol were made before, during and after treatment. In addition, BP and chemistries (SMAC 20 ) including Cr were performed.

There were no changes noted in total cholesterol, HDL, or LDL cholesterol.

There was a 27% decrease in triglycerides from 244 mg dl to 178 mg/dl during treatment with a trend back toward pre-treatment levels (196 mg/dl) within one month after discontinuation of therapy. Chol/HDL ratios remained unchanged 5.8 vs. 5.2 with no changes noted in blood pressure, serum creatinine, nor eyclospo~in levels.

In conclusion, the results of fish oil treatment on lipids in patients receiving cyclosporin are essentially the same as those described in patients with a variety of lipid disorders be they primary or secondary to various renal disorders.

Whether or not the lowering of triglycerides alone by omega 3 fatty acids will have any long term beneficial effects on cardiovascular disease remains to be determined. Departments of Pediatrics, University Freiburg I, Germany, and Budapest 2, Hungary Endothelin 1-21 (E) is a peptfde that is vasoactive and potentially diuretic. It is produced by endothelial and renal epithelial cells, in vitro. Renal excretion probably reflects intrarenal (epithelial cell?) E production. Renal excretion of E determined by RIA was highest in preterm neonates (N=20, gestational ages 25 to 38 weeks) at 25 weeks and decreased with age (E/crea). In children age 4-16 years excretion of E after water diuresis increased from 98 to 278 pg/mg creatinine (p<0.01, N=4) and after furosemide from 113 to 220 (p<0.01, N=5). In children with biopsy proven renal disease the excretion was as follows (pg/mg creatinine): Focal segmental sclerosis (N=8) 168• Minimal change disease (N=5) 138• Lupus nephritis (N=2) 92• After renal transplantation (NTx) under cyclosporin treatment (N=I2) urinary E was 185• pg/mg. These results were significantly higher compared to the excretion in children of same age without renal disease with 57• pg/mg creatinine.

Endothelin excretion is significantly higher in neonates and infants which may contribute to the increased intrarenal resistance resulting in lower glomerular filtration rate. In children with renal disease endothelin is enhanced and highest in transplanted children with cyclosporin treatment suggesting that intrarenal mechanisms may influence vascular resistance potentially through endothelin release. In this report we describe a first large series in which a novel method for obtaining isolated glomeruli (GL) from human kidneys was evaluated. We modified FNA processing to obtain glomeruli from adult and pediatric transplanted (n=56) and native kidneys (n=6). FNA was done with 25-23 gauge spinal needles using classical Helsinki method and the aspirate was suspended in 5ml of RPMI 1640. GL in the aspirate were trapped by the following procedure: Centrifugation of the sample in gelatine coated tubes at i000 rpm for i0 min, removal of the supernatant and addition of 3 drops of normal human plasma to the pellet. In the next step, 3 drops of I:I000 solution of bovine thrombine were added to produce a stable clot which retained GL in its fibrin mesh. The clot containing GL was processed by the conventional methods for light and electron microscopy. Results: 5-6 GL per sample were obtained in 44 out of 62 samples (70%), 25% of FNA had no GL, in 5% GL were distorted. The FNA diagnosis of pathologic conditions: Rejection Neph., Membranous Neph., Minimal Change Dis., Diabetic Neph., FSGS and Amyloidosis was confirmed in all cases (n=13) where parallel tissue biopsies were also done. There were no complications and patients accepted repeated FNA when required. The advantages of this method are its simplicity and safety,the disadvantages -lack of information on renal parenchyma. We conclude that FNA method can be recommended for study of GL pathology especially in solitary kidneys and in follow-up of renal therapy. The messages transduced by cytokines are critical to the response to alloantigen. Graft infiltrating cells are responsible for the development of either rejection of or tolerance to the allograft. There is increasing information that different patterns of cytokine production at the site of some immune responses may determine or reflect the direction of the ongoing immune response (Modlin et al 1991) . Determination of the pattern of cytokine production by" peripheral blood or graft infiltrating cells may be helpful in monitoring the immune response to the allograft and selection of immunosuppressive therapy. We have developed a nonradioactive technique to quantitate the presence and frequency of cells generating mRNA for interleukin 2 (IL2). Peripheral blood mononuclear cells are stimulated with phytohemagglutinin and phorbyl myristate acetate and sedimented onto microscope slides. After fixation they are stored or hybridized directly. Digestion with proteinase K, prehybridization and hybridization are performed using standard techniques. A 24 base antisense oligonucleotide against human IL2 is 3' labelled with digoxigenin (DUG) (Boehringer Mannheim) labelled dUTP. Immunohistochemical detection is performed with a monoclonal anti-DIG antibody, a biotin-labelled second antibody and preformed complexes of avidin-biotin-alkaline phosphatase (Vector) and finally nitroblue tetrazolium. Slides are counterstained and specific staining is quantitated using image analysis. Patients (pts) whose sera contain high levels of anti-class I HLA antibodies (abe), as measured by>75% reactivity against a panel of T lymphocytes in the complememt-dependent cytotoxicity (CDC) assay, have inferior access and success of renal transplantation. There are currently no safe and successful ways to reduce such sensitization. In vitro, IVIg down regulates T and B cell immune responses of HSDP (Yadin, SPR 1991) and Jordan has suggested that in vivo administration dramatically reduced anti-HLA ab in one HSDP (ASN, 1991) . In 3 HSDP we gave I'r 400 rng/kg once weekly for 4 weeks. One pt also underwent plasma exchange (PE) before each IVIg infusion. We then examined the effects on the HSDP's anti-class I HLA abs, as measured by the CDC panel reactive antibody (PRA) of the HSDP's sera after each infusion and at 2, 4 and 8 weeks after the last infusion. With PE and IVlg there was no change in the PRA Of the undiluted sera, but at 1:4 and 1:16 dilutions the PRA decreased from 27-60%. In one of the pts who received IVIg only, the PRA declined 14-22% when sera were diluted 1:4. Both pts also had subtle decreases in the strength of discrete anti-class 1 HLA ab specificities (HLA A1 and A24). These effects were not long lasting: in both, PRA returned to baseline by 2 weeks after treatments. To explore the mechanism of this subtle effect, we examined the IVIg for anti-HLA class I anti-idiotypic (id) abs against 4 specificities in 10 experiments, A-11, A-24, A-26 and B-35, using the short anti-id CDC ab blocking assay. We found anti-id abs in 7 of the 10 experiments. We conclude that in HSDP, IVIg, either alone or with PE, had only a subtle effect in decreasing anti-HLA sensitization, perhaps mediated through anti-id. This effect is short lived, and to be successful either a different IVIg regimen and/or adjunctive immunosuppression may be necessary. In animal model Endothelin (Et) has an important role in the pathogenesis of ischemic acute renal failure and Cyclosporin induced nephrotoxicity. Recently, Et has been proposed as plasmatic marker of acute vascular rejection in kidney transplant. We investigated the immunohistochemical distribution of this peptide on renal biopsies of kidney transplant patients. In the last three months, 10 biopsies were analyzed: 8 out of tO were scheduled biopsies; the other two were performed during episodes of acute rejection. At the same time, Et plasma level and Et urinary excretion were evaluated using a standard radioimmunoassay method. In 4/10 biopsies, With no r~levant histopathological changes, only a weak Et staining of vascular endothelium was observed, as in normal kidney sections. In the other six biopsies a positivity of inflammatory cells <6/6), tubuli <4/6), and glomeruli (3/6) was revealed, according to the histological evidence of foci of inflammatory infiltrate, tubular changes and glomerular hypercellularity. Excluding one case of acute vascular rejection, the plasma level and urinary excretion of Endothelin were not significant different to the normal values of healthy .age matched subjects. Our preliminary results suggest that Et could be a local agent of renal damage in different pathological conditions. Its significance as sistemic marker to monitor the graft function and survival has to be further investigated. Growth retardation is a common problem in children with chronic renal failure (CRF). Recombinant human growth hormone (rhGH) treatment has given increased height velocity in CRF children older than 3 years. If this treatment is also effective in younger children has, however, not previously been shown. In the present study two boys, 15 and 20 months old, with CRF (CIn 22 and 20 ml/min/1.73m 2, respectively; single injection of inulin~ from refluxnephropathy and cystic kidney dysplasia, respectively, were given rhGH (GenotropinR; 0.15 IU/kg/d s.c.). Both had been short (67 ca, -6SD; 77 cm, -3SD), but apparently well-nourished (8.6 kg, -2SD; 9.5 kg, -2.2SD), and it had not been possible to improve growth by normalization of the acidbase and calcium-phosphate balance, or by tube feeding. During the first 4 months of rhGH treatment good catch-ut) growth (9 cm=27 cm/yr; 7.3 cm=22 cm/yr) was seen, after which the patients tended to follow a new height channel (at 10 months: -2.2SD; -1.6SD). After 6 months the GFR (CI,) was unchanged (24 ml/ min/1.73m 2) in one of the patients }~ut had possfl~ly declined somewhat in the other (15 ml/min/1.73m2). A severe vomiting problem in one of the patients did not improve. Serum concentratio~ of insulin-like growth factor I (IGF-I) were low (23/~g/1; 29/~g/1) before rhGH treatment and 12h serum profiles showed a single GH peak (max: 20 t~g/1; 8.5 /~g/1) and elevated levels of IGF binding protein-1 (IGFBP-1; range: 89-169 t~g/1; 160-300 #g/l) inspite of high or normal insulin levels (range: 33-116 mUff; 15-28mU/1). After 3 months of rhGH treatment the IGF-1 levels were markedly increased (171 ~g/l; 205 ~g/1). The results encourage rhGH treatment also in uremic children below two years of age in order to achieve normal stature. HIV nephropathy (HIVN) is now considered as a distinct clinicopathologic entity, and evidence points currently to a direct implication of the HIV in HIVN. Proteinuria and azotemia are the more frequent biological symptoms, and mesangial hyperplasia, focal and segmental glomerulosclerosis the predominant histological glomemlar lesions. Incidence of HIVN, defined by biological markers, has been reported to reach 57% in perinatally infected children (CHANDER et al. Kidney int 1989) . As since June 1987 all of the perinatally infected children followed in our institution are treated with antiretroviral agents as soon as the diagnosis is made -ie at least two plasma mononuclear cells culture positive for HIV -, the study of the incidence of HIVN in this population is of particular interest. We prospectively screened outpatient symptomatic (S) and asymptomatic (A) non febrile perinatally HW infected children for biological markers of glomerular abnormality. BUN and plasma creatinine (PCr) were measured in a discrete analyser (RAXT, Technicon); microalbuminuria was measured by nephelometry on a single morning urine sample, and results were expressed using urinary microalbumin (mg) / ereatinine (mmol.) ratio (U~A/Cr); GFR was estimated from PCr according to the Schwartz method; hematuria and proteinuria were checked by dipsticks. Results: 27 children aged 44 month on average (range 5-120) have now been studied (59% male, 55% black); 2 children were asymptomatic (A) and 25 were symptomatic (S). Among the S children, 7 had AIDS according to the 1989 CDC criteria, 16 had a CD4/CD8 ratio < i., 10 were positive for P24 antigenemia. All the dipsticks were negative for proteinuria and hematuria; mean BUN was 4 mmol./L (range: 1.8-6.5); GFR remained in the normal range for age: before 12 months of age, mean GFR was 55 mL/mn/1.73 m2 (range 50-60); between 12 and 24 months mean GFR was 98 mL/mn/1.73 m2 (range 82-112); after 24 months mean GFR was 115 mL/mn/1.73 m2 (range 88-163,); UgA/Cr was upon 3 in 4 patients among which 1 had AIDS. Conclusion: We observed minor biological markers of glomerular abnormality in this studied population of non hospitalized HIV infected children but no nephrotic syndrome nor chronic renal failure was found. Despite these results must be asserted by a larger sample, it raise the question of the role of an early antiretroviral therapy for the prevention of HIV nephropathy. The survival time of patients with CF has increased significantly in the last 10 years. This has caused new problems. A growing number Of our patients older than 15 years show severe renal complications like renal stone formation, immune complex nephritis or diabetic nephropathy. 3/26 patients (a~[ed 18,20 and 21 yrs.) had a hematuria due to calcium oxalate kidney stones. 7/14 patients had an urinary calcium excretion of more than 4 mg calcium/kg bodyweight/day. Stone formation can be explained by enteral hyperoxaluria due to fat malabsorption in CF. 2 patients (22 and 27 yrs.), suffering from chronic pulmonary infection (pseudomonas) had elevated serum levels of pseudomonas antibodies and IgA. Both developed purpura, arthritis, microhematuria und proteinuria of > 3g/d. While physical symptoms disappeared both hematuria and proteinuria persisted and serum IgA levels increased to 1500 mg/dl. There was a temporary decrease of creatinine clearance (62 ml/min/1,73m') in one of these patients. Kidney biopsy revealed severe IgA-nephropathy which could be explained by increased IgA production due to chronic pulmonary infection and diminuished liver clearance of immune complexes in CF.

A third adult patient with severe pulmonary problems suffered from diabetes mellitus, a well known complication in long-term CF. She developed hypokalemia, proteinuria and renal insufficiency. The biopsy showed a combination of diabetic nephropathy and IgA/IgM-nephropathy. She died in renal failure shortly after dialysis was started. The growing number of CF patients reaching adulthood makes the nephrologist an important partner in the care of long-term CF patients. Ultrasound is now the primary investigation of the urinary tract but existing reference ranges for size are of limited value because they are based on small numbers of children attending hospital. In this study 858 healthy children (0 -19 Yrs, 51% Male) w~re investigated in the community with a portable real time scanner. A standardised procedure was used to examine and measure the urinary tract.

Data collected was used to prepare centile charts for kidney size.

Reproducibility (intra-observer error) based on 62 duplicate examinations was 2.4% for kidney length and 8.4% for volume

The relationships between kidney volume and body weight and kidney length and height were linear.

Male kidneys were bigger than female kidneys when matched for age.

Difference: 1-2mm for mean kidney lengths. Rapid kidney growth was observed in infancy and in adolescence. Asymmetry in kidney size was detected at all ages.

In 67% of children the left kidney was the bigger.

Size of the collecting system did not vary with age or side.

97th Centile for the pelvicalyceal diameter was 7mm, Upper Ureter: 8mm. End-stage renal disease is a major problem in aboriginal Australians with an over-all incidence 15 times that of the caucasian population. Diabetes accounts for a high proportion otthis, but there remains a ten-fold and, in some areas, up to a 100-fold increased aboriginal incidence, even when diabetes is excluded. In such areas almost half the population has an important degree of proteinuria by the age of 40 years. The reason for this is obscure but preliminary studies suggest a high correlation between haematuria of glomerular origin in school children and chronic renal failure in adults. Beta-haemolytic streptococcal skin infections are extremely common in these communities with high anti-DNA'ase B titres in over 90% of the children. Outbreaks of acute post-streptoccocal nephritis (AGN) occur every few years. In a follow-up study of 48 children following a recent epidemic of AGN, 14/35 children had haematuria 14 months later. This was comparable however to the incidence in age-and sexmatched controls (13/30). This had fallen to 3/30 patients after three years follow-up. Histological lesions in aboriginal adults with chronic renal failure show an unusually high incidence of membrano-proliferative glomerulonephritis, non-IgA mesangial disease, glomerulomegaly and diabetic glomerulosclerosis. Subepithelial humps are found in a number of different types of lesion suggesting a possible streptococcal aetiology. We are exploring the suggestion that chronic and/or frequent streptococcal infections in childhood, in conjunction with possible genetic and other environmental factors, may lead to a different type of immune response, and hence a different pattern of renal disease than that found in classical AGN. An impaired renal Isemodynamic ressonse to amino acid (AA) infusion has been reported as a poor prognostic factor ]n some chronic renal diseases ACE inhibitors decrease urinary protein excretion and it has been suggested that they might s]ow the progression of renal damage. GFR (Inutestl and RPF (CPAH) increases (delta GFR and delta RPF) after AA infusion (Freamine 85%, 290 mg/min/l.73, sqm for 2 hrs'. a:nd urinaryDrotem excretion<UPrV! were studied in S adolescent males affected by IgA nephropathv and in 7 normal controls Patients underwent the same study aften 15 days of treatment with Enalapril (E) 02~ mg/kg/dau All of tlnem had hystopathological findings of focal proliferation with crescents m 20 30% of glomeruli, normal renal function and blood ~ressure Basehne urinary protein excretion was above gr/day. Results in mean (SD); delta GFR or delta RPF are defined as :(basalinfusion value)/(basal+infuslon)/2;*p*. 

The epidemtologte ~ of renal di~,~ with funetionol impairment in cMldren are still very week. In Europe, date concerning patients who undergo retjular dialyze and tronoplanf~tion during childhood can be obtained from the EDTA Re(jietr9, while no egsternoflc information ts ~lleble on children who reach termi eel renol f~l urn be~nd podiatric n~e. Renal size was measured by real-time ultrasono~ graphy in 567 Filipino children with no recognizable renal disease from March 1988 to March 1991. The subjects were grouped into age categories ranging from zero to 16 years.

For each subject included in the study, the following data: were recorded:

age, sex, weight, length/height, body surface area, blood pressure, and renal length and width of each kidney.

The mean and standard deviation were determined for the following renal ~arameters: length, width, and a postulated renal index".

The greatest rate of kidney growth was found to occur during the first year of life. The left kidney was slightly, but significantly, longer than the right.

Renal length significantly correlated with body height -better than with age.

In this series, the mean renal length in the different age categories was consistently shorter than their Caucasian counterparts.

This study was a preliminary attempt to set standard values of kidney size in Filipino children. P-IlIA.9

A. Gianviti*, M. Greco, P. Barsotti*, Bambino Gesu Children's Research Hospital, ~-a Sapianza" University, Rome 00100, ITALY Acute tubulointerstitial nephritis (AT/N) can be due to infection, drugs ingestion and systemic diseases. We report the case of identical female twins who developed ATIN 1 year apart with identical clinical and histnlogleal picture. Cases: Case i, at 14 years of age, and Case 2 at 15 years, both showed pal/or, weight less (3-4 kg in 10-30 days). At admission: (Case 1 -Case 2): ESR: 120-112ram, serum creatinlne: 160-150 Izmol/1, Hb: 10.2-10.5 g/dl, serum protein: 8.4-8.8 g%, gamma globulin: 29-20%, lgA: 2260-2180 rug%, ANA positive (+ +) only in Case 1 A-DNA, A-histone and antleardiollpin antibodies negative in both; C3 and C4 were normal. Protenurla: 0.5-0.7 g/day; slight mlcrohematuria in both. HLA B W22,40,DR4,W6. Only Case 1 developed bilateral uveitis 3 months after the onset. In both sisters, history revealed the use of nimesulide (FANS) and eotrimoxazole respectively 3 months and 10 days before symptoms. Renal biopsies: Typical ATIN with eosinophilla; no glomerular lesions at light and electron microscopy and negative immtmofluorescenco (IF) staining for IgG, IgA, IgM, C-B, Clq, fibrinugen. Kappa and lambda fight chains. Both sisters were treated with Prednlsone (lmg/kg/day, tapered off until 0.amg/kg/every other day). In Case 1 -therapy was started two months after the onset of the symptoms, while in Case 2 it was started immediately. Clinical and functional improvement was observed. Treatment was stopped after 1 year in case 1 & after 14 months in Case 2. Follow-up: After 15 months without therapy in Case 1 & 8 months in Case 2, GFR is 100 myra'/1.73 sqm and 110 ml/m'/1.73sqm respectively; both eases have negatiuve urinalysis. Comments: To out knowledge this is the first description of ATIN with familial occurrence as well as in twins. The poss/bi/ity of a SLE can be reasonably excluded beeanse of the absence of 4 erlteda of ARA, the absence of HLA DIL3 and the presence of isolated tubnlointerstitial lesions without glomerular abnormalities with negative IF staining. On the basis of our findings, it can be hypothesized that in our cases a genetic predisposition to ATIN exists, probably assodated with a drug hypersensitivity. Renal Unit, Adelaide Children's Hospital, Adelaide, South Australia 5006 7300 kindergarten children have been screened for renal disease by measuring blood pressure, growth percentiles, and frozen first morning urine for blood, protein, glucose, nitrites and Beta-2 microglobulin ~2M).

The screening abnormality rate was 6.6% (blood pressure >99th percentile for age 1.1%, elevated /~2 M 2.4%, proteinnria 0.15%, iaaematuria 2.3%, nitrites 0.26%, height significantly reduced 0.3%). Identified children were followed by clinical investigation, repeat urine assays and renal ultrasound where indicated.

On review, 10.9% of those initially hypertensive had persistent hypertension resulting in the detection of aortic coarctation (1), Wiim's tumour (1), new vesico-ureteric reflux (VUR) (2) and old VUR (4) . Of those children detected with raised fl2M, 2.3% showed persistently raised levels. Abnormalities detected were nephritis (1), idiopathic hypercalciuria (1), renal dysplasia (1) and old VUR (1).

In those detected with haematuria and/or proteinuria the following abnormalities were found -biopsy proven significant nephritis (3), persistent proteinuria and/or haematuria (26), VUR (1) and dominant polycystic kidneys (1) . Of those detected with nitrites, 83% (12) showed positive urinary tract infections requiring treatment and one had VUR.

The study suggests the screening programme is effective in detecting renal abnormalities.

The use of frozen first morning urine specimens reduces the false positive rate for proteinuria and haematuria, and facilitates urine collection while allowing measurement of/~2M. Active metabofites of vitamin D are known regulators of calcium homeostasis. Furthermore, a participation of 1.25D in the regulation of immtmocompetent ceils proliferation was reported recently. We evaluated in vitro action of different doses of 1.25D (0.01-1.0 riM) and CHL (0.1-30 ug/ml) on blood lymphocyte proliferation in 8 children with different morphological types of GN resistant to cytotoxic treatment. We fotmd that L25D has a dose dependent antiproliferative effect. Treatment of the cells with 1.2513 raised their anti-proliferative sensitivity to CHL in 7/8 children. We carried out a retrospective analysis of 20 children with GN, resistant to immtmo-suppressive treatment, who received CHL and I~OI-ID during 2-4 months lc~OI-ID, transformed in the fiver into 1.25"D, was prescribed in the dose of 0.5-I.5 ug/day for the correction of hypocalcemla and osteoporosis. In 14/20 children a remission was achieved and lasted for more than 1-2 years; in 6 more than 5-7 years, without a previous remission of GN. The remission in the children with GN receiving 1.25I) and CHL was perhaps caused by synergistic actions of these drugs. Ten months (M) following allogenic or autologous BMT, 1/3 patients (pts) develop hemolytic uremic syndrome (HUS) or isolated renal insufficiency with or without hypertension. Renal pathology is analogous to radiation nephritis and is attributed to preparatory radiation. We have performed BMT in 69(44M,25F)children;42(23M, 19F,ages 2-19yrs)survived >6 months. BMT was performed for acute lymphoblastic leukemia (6),aplastic anemic (2),myelodysplasia (2), myelogenous leukemia-chronic (2),acute (1 ),neuroblastoma ( 1 ),and Wiskott-Aldrich Syndrome(l). Pre-BMT conditioning included cytosine arabinoside,cyclophosphamide, methyl prednisone and total body irradiation 1400 r 9 fractions. Busulfan 4mg/kg/d x2 was used in 8/15 pts. Bone marrow donors were either family members (7)or unrelated (8) . All marrows were T-cell depleted using a CD3 antibody. Supportive therapies included cyclosporin A (stopped by day 180), Acyclovir,Trimethoprim sulfa,IV gamma globulin and CMV negative blood products. All pts engrafted. Graft-vs-host disease was < grade 2. Renal involvement occurred in 15/42(10M,5F)and was characterized by hematuria,proteinuria, hypertension,rising BUN, creatinine and reduced GFR in 13/15 pts. 6 pts had HUS-like syndrome 8M after BMT. 7 had isolated renal insufficiency(RI). 2/15 pts without clinical renal involvement developed lymphoproliferative renal infiltration (LP) on tissue examination. 4 pts(2 HUS,2LP)died. Renal functions improved in 4(2 HUS,2 RI);stable in 7. Conctusions:l)Long term renal toxicity is an added complication of partially matched BMT occurring in 1/3 of the pts manifesting as HUS or isolated renal insufficiency. 2)Preparatory radiation is the most likely etiology of HUS-like syndrome while cyclosporin may contribute to renal insufficiency. 3)Improvement in renal functions occurs in 1/3 of pts. Clin/cat features and natural course of acute TINU syndrome in 5 adolescent pts (3 female, 2 male) are presented. Initial non-specific symptoms proceeding nephropathy by 3-4 weeks were anorexia and weight loss ha all, fever and malaise ha 3, abdominal, flank & joint pain ha one pt each. Except for pallor, no further clinical abnormalities were found. Inflammatory syndrome consisted of markedly increased ESR in all 5, high plasma proteins and gamma globulins in 4 pts. Urinalysis showed moderate proteinuria, sterile leucocyturia, glycosuria, aminoaciduria and isostheunria in all except for aminoaciduria ha 1 pt. Plasma creatinine was increased in all. Renal biopsy (2 pts) revealed acute interstitial nephritis. Anterior uveifis, which appeared later, was successfully treated with topical steroids.

Renal functions completely recovered within a few months ha 4 pts and markedly improved in one whose plasma creafi.aine was L2mg/dl after 2 years.

Despite the fact that renal biopsy was not performed in 3 of our pts, the combination of an acute non-oligurie and non-hypertensive renal failure and signs of tubular dysfunction together with a particularly benign course strongly suggests the acute TINU syndrome, presumably idiopathic, as other possible causes could not be identified. Pereutaneons renal biopsy is a common method for diagnosis. Sometimes complications may occur. The aim of this article is to present a very rare complication: an A-V ~tula treated with selective asteriography & placing a platinum mlcrocoil. A male patient (11 years old) was admitted with periorbital & pretibial edema, at the age of 2.5 years, M;nlmal Change Disease characterized by edema, hypo~dbanlnemia, hyperlipedemia, proteinurla, normocomplementemla, normal serum BUN and creatiulne levels had been diagnosed. As remission was ashieved with prednisoloee treatment. After 8 years, when a new attack oceured, a renal biopsy was performed to appraise the prognosis. Pcreutaneons renal biopsy was done with ultrasound guidance. Macroscopic hematurla was seen for ten days. Minimal perirenal fluid collection in the lower pole of the left kidney was detected with ultrasonography. Colour doppler ima~n~ sunography suggested an A-V fistula.

Selective renal arteriography revealed two aneurysms 6mm in diamter in the distal end of lobular artery in the lower pole. Superselectively, the lobular artery with aneurysmatie dilatation was eatherized and the bleeding site was localized.

Permanent transeatheter occlusion was done by placing a platinum microcoil into the aneurysm. After this procedure hematuria stopped.

This angiographic embolization is a new method for prolonged macroscopic hematuria complicating a renal biopsy. There has been a suggestion in the literature that lgA nephropathy may be familial. Genetic factors may influence the development of the disease in association between HLA antigen and lgA nephropathy. At the present time, no conclusion can be drawn. In this paper, 2 siblings with typical IgA nephropathy in two families are presented. The relation between HLA and IgA nephropathy disease was not detected in these family studies.

The first family: a 14 year old girl and her 12 year old brother, were admitted with macroscopic hematuria. All laboratory investigations, including serum lgA levels (104mg/di & 102mg/dl) were normal Histological findings of the kidneys showed deposition of IgA in the mesangium of the glomeruli.

The second family:. A 15 year old boy and his 9 year old brother were admitted with macroscopic hematuria in the first and gross hematuria in the second. Laboratory investigations were normal. Serum IgA levels (287 mg/dl) were normal in the first patient, elevated (485 mg/dl) in the second, lgA deposition was observed in the glomerular mesangium in these patients. Literature on the spectrum of renal disorders in children in Africa is scanty. A renal register was therefore opened in 1986 at the University of Port Harcourt Teaching Hospital which serves a population of one million Nigerians and over 5 years (1986-1991) , 699 children aged 0-16 yrs with various renal disorders were recorded.

68.9% had Urinary Tract Infection but none had reflux Nephropathy; 14.6% Nephrotie Syndm6me (NS); 11.4% Acute Glomerulonephritis (AGN); 2.4% Wilm's Turnout; 1.6% Obstructive Uropathy; 0.4% Haemolytie Uraemie Syndrome (HUS); 0.6% miscellaneous congenital abnormalities.

Unlike studies in Western and Northern Nigeria, and East Africa, where minimal change NS was considered non-prevalent; 24 out of 102 children with NS (23%) have been documented to have minimal change NS which have continued to respond to steroids despite frequent relapses. Sixteen children developed end stage renal failure (ESRD) (i.e. 3.2 children per year per million of the populaticn) 12 were secondary to chronic Glomerulonephritis; 2 PU~7; I chronic pyelonephritis ; i Prtur~ Belly Syndrome; i HUS and the cause was unknown inl.

Notable in this study is the rarity of reflux nephropathy, and congenital renal abnormalities ; the presence of steroid sensitive NS and the incidence of ESRD approaching figures seen in the Western World. 50-90% of mushroom poisoning related deaths are due to Amanita phalloides group, in which there is a latent period of 12 hours or so before onset of symptoms. PhaUotoxins act first, causing gastrointestinal symptoms and after a remission period of 3 to 5 days renal and hepatic failure develop due to the act of amatoxin. Early diagnosis is imperative and aggressive therapeutic measures must be instituated promptly to improve the outcome.

Three brothers with poisoning due to Amanita phMloides were admitted with gastrointestinal symptoms beginning 12 hours after ingestion. Jaundice and hepatomegaly were not present but liver enzymes were moderately increased. Hemoperfusion was performed 16 and 40 hours after ingestion respectively along with conservative therapy. Alfa amanitin was demonstrated by thin layer chromatography before and after the first hemoperfusion session but was not detected after the second. Liver enzymes showed marked increase for two days after hemoperfusion but later decreased and returned to normal levels on the 28 m day. A cousin of our patients who also had ingested Amanita but refused hospitalisation and therapy succumbed. We believe that hemoperfusion is life saving in Amanita poisoning besides conservative therapy. It has been suggested that in acute poststreptococcal glomerulonephritis (APSGN), streptococcal neurominidase may remove sialle acid from some normal plasma or tissue components, thus rendering it antigenic. We investigated serum and urine free static acid levels, using thiobarbituric acid method, in 30 patientS with APSGN. Initially, free slafic acid levels were found to be significantly elevated in the sera of patients with APSGN (75.0 ~ 21.0pgr/ml). Serial determinations in 30 patients indicated that free sialic acid levels decreased with time, usually returning to normal levels after 12 weeks. Control subjects were 20 healthy children and 10 patients with chronic renal failure. Determinations in patient~ chronic renal failure were found to higher (14.3 $1.05pgr/ml) than the control group (p<ll.05). This level was significanty lower than those of APSGN patients (p<0.05). In our study, negative correlations could be found between serum h-ee sialic acid and C3 levels. Urinary siaile acid levels were no~ related to serum levels and were not markedly different in patient~ and control subjects. We conclude that neurominidase activity and antiglobuUn forma tion may be a central factor in the pathogenesis of APSGN, but we think that further studies, including other renal diseases, will help to define whether this phenomen is specific for APSGN or not. Complement is considered to be one of the factors contributing to the severity and progression of IgA nephrathy. Immunofluorescent studies in IgA nephropathy have shown the presence of MAC neoantigen or polymerized C9 in glomerular immune deposits. Since S-protein is invariably colocalized with C5b-9 deposition, it is questionable whether the MAC found in human nephritic tissues is physiologically active. Investigation of the combination of an inherited terminal complement deficiency and glomerulonephritis in a single patient could elucidate the pathogenetic role of MAC.

Three Japanese young males with congenital cg deficiency and primary IgA nephropathy are reported. The cg deficiency was discovered through mass complement screening. Hematuria and proteinuria was detected at the age of 8 or 9 years as a result of annual urinary screening tests for school children. Renal biopsy showed focal and segmental mesangial proliferation with small epithelial crescents in one patient, and mild, diffuse mesangial proliferation in two. IgA and C3 were deposited predominantly in the mesangial area in these patients. Electron microscopy revealed electron dense deposits predominantly in mesangial/paramesangial zones.

Immunohistochemical staining in renal biopsy tissues from one patient showed mesangial staining for C5, C8, and S-protein, but staining for C9 and C5b-9 neoantigen were completely negative. These results show that the formation of C5b-9 complex is not essential for the induction of human IgA nephropathy, and also for mesangial and even epithelial cells proliferation. 

A phenomenon of renal hypouricemia was observed after A.ph. poisoning. In six patients with normal Iiver function renal handling of uric acid (U.A.) was estimated six weeks after A.ph. intoxication. FEHA was elevated in four patients before probenecid te~, and their serum UA were below 2,Omg/dl. After probeneeid administration FEuA was 146,0% 106,7%, i03,1%, 84,8% and 83,1% respectively. In the sixth patient in whom the basal UA concentration was 3,3mg/dI, FE. A 8,3%, FEu~ increased to 45,3% after probenecid a~ministratio~.

In three cases UA level in serum and urine was examined 24 hours after probenecid test. Considerable hypourisemia (0,4mg/ dl, l,Omg/dl, 1,Omg/dl) and high values of FEuA (107,4%, 45,6%, 47,8%) were sustained. Before pyrazinamide administration elevated FEnA was noted in three patients, one of whom had hyp~d~icemia. After pyrazinamide, FEuA values decreased below 0,5% in all children. In conclusion: l/ Hypouricemia found after A.ph. poisoning in children is of renal origin due to proximal tubule injury, 2/ Tubular hypersecretion is a possible mechanism leading to the increased UA clearance, 3/ The observed tubular defect may persist long after liver function tests normalize. CompensaSmry renal hypertrophy is stimulated by the loss of renal tissue,either because of its removal(nephrectomy)or damaging processes.The com~onest of these is in children-renal scarring induced by chronic inflammatory process and vesico-ure teral reflux.If an end is put to them -even the advanced scarring changes,resulting already hyper tension and incipient renal insufficiency(>creatinine,>urea,<GFR) may gradually regress, owing tothe compensatory hypertrophy not only of the healthy kidney but also of the damaged one.In the latter--hypertrophy comes out of its still remaining active cells and may be so intensive,that in few ye are the hypertrophied kidney makes appearance of a "tumor" and regains most of its functional efficiency.Azotemla and hypertension withdraw. 5 children with advanced reflux nephropathy and incipient renal insufficiency have been followed for I0 -20 years.During one decade they ha ve recovered 80% of their kidneys'functional abi-lities~thanks to the immense compensatory renal hypertrophy.This makes the prognosis for children with reflux nephropathy -much more favorable,at least for some of them. 

Our aim is to present a peculiar type of renal pathology -so called DNCOC (Ignatova N.Vel'tlshchev Yu. Pedlatr.Nephr.,N.,1982) -on the data of 100 patients (pts) aged 2-15 from different parts of Russia, 36 children and their relatives selected during an epidemlological study in Moscow, and 30 healthy children (control group). The DNCOC signs were: high frequency of urolithiasls COL) -25% (control -1%) and pyelonephrltis -27% (control -2%) in members of families, in pts -hamaturla, constant COC: aggregated crystals size more then 12 mkm on light microscopy. Special membrane investigation showed the signs of cytomembrane instability, ethanolaminuria 763 _+ 62,4mg/24h, in control -371,2 -+ 17.9mg/24h, lipiduria 445 -+ 42 unlts/24b, in control absent; similar to those in their sick relatives. Nobody had dyseleetrolytemia and acid base balance disturbances. Additional syptoms: 54% -arterial hypotension 56% -different signs of allergy, 23%decrease of urine daily volume with high specific gravity, 50%-hyperoxnluria, 33%

decreasing of anti-crystal forming ability of urine towards calcium oxalate. Ca/cx ratio was increased in 11% pts. All 12 biopsied pts had tubule-interstitial changes and 1 -some signs of mesangial proliferative GN. So, DECOC is one of the variants of oxalic nephropathy with possible evolution to UL (according to familial data) or in chronic abacterial .or bacterial tubnlo-interstitial nephritis. Probably this pathology develops in cases of familial cytomembrane instability. It is clear that DNCOC is a rather frequent syndrome (13% in the structure of renal diseases in our nephrology department). The question for further study: is it a peculiar syndrome or the early stage of UL and/or nephritis.

A.T Huse.ynov*, O.B. Svj'atkina~ E.A. Kharina, M.S. lgnatova~ Y.E. Velttshchev

It has been shown that lipoxygenose metabolitas of arachidonic acid such as monohydroxyeicosatetraenoie adds play a role in the pathophysiology of kidney in experimental animal. However, the potential involvement of 5-12-15 HETEs in human GN remains unclear.

We have studied the levels of 5 HETE, 12 HETE and 15 HETE in urines of 9 children with GN. Active NS was observed in 5 children at the time of study. Mesangioprollferative GN (MsPGN) was revealed in 4 patients and membranoprollferatlve GN (MbPGb 0 in 1 patient of this first group. The second group consisted of 4 children who never had /',IS and proteinurla more than 3.Og/L 3 children had MbPGN and 1 child had MsPGN. Analysis of HETES was performed by using RP-HPLC in fresh morning samples of urine and expressed as ng/10mi of urine.

Results: the level of HETEs in urine in patients with active NS was significant higher in comparison with patients without NS ( The significance and importance of these inllnmmntory mediators in the pathogenesis of different clinical forms of GN in children will be discussed. The aim of this investigation was to study the a-IFN influence both GN and HBU in patients (pts) with GN associated with HBV.MATERIAL AND METHODS: 30 pts (14 boys and 16 girls) aged 3-14 with nephrotie syndrome (NS)+/hematuria were studied. Renal biopsy was done in 21 pts:12 had mesanglal proliferative GN and 9 -membranoproliferative GN. Markers of HBU (HBsAg, HBeAg, anti-HBs, anfi-HBe, anti-I-IBc and anti HBe IgN antibodies) were investigated by enzyme immunoassay in blood in all cases before and after treatment, a-IFN was used in doses 50000 IU/kg daily per rectum during 1-3 months. Group 1 (8 pts) received a-IFN only;, group 2 (9 pts) -hnmunosuppressive therapy (IT) simultaneously with a-IFN and group 3 (13 pts)only IT inciuding prednlsolone 1-2 mg/kg daily, azathioprine or cyelophosphamlde 2-3 mg/kg daily (control group). RESULTS: The decrease of NS signs after treatment was observed in all groups, !but more often in 1 and 2 (table * -before and ** -after). In 19 pts (4 from 1:7 from 2:8 from group 3) serum level of alanine amino-transferase (ALT) as sign hepatitis was elevated in 1,5-5 times before the treatment. After the treatment the increase of the frequency of elevated ALT level was only in pts of group 3. In pts of groups 1 and 2 ALT level fell into the normal range (P<0,01).

Markers of HBV infection were observed in all pts, but markers "suggesting active viral replication (HBsAg+/-HBeAg+/-anti-HBe Ign) were observed in 20 children (5 in 1:8 in 2 7 in group 3). 10 pts had anti-HBs, anti-HBe and/or anti-HBe IgC. The frequency of HBV markers detection HBsAg+/-I-IBeAg +/-anti I--IBc Ign) was decreased during treatment in groups 1 and 2. In contrast HBV markers suggestive of active viral replication were increased in groups 2 and 3 (p<0.O2). The purpose of this study is to know the long-term prognosis and discover the prognostic factors of IgA nephropathy in children. We followed 39 patients (25 boys and 14 girls). The main urinary findings were proteinuria and hematuria (79.5%) and 6 patients showed nephrolic syndrome (NS). Abnormal urinary findings subsided in 31.5%, improved in 21.1%, remained stationary in 26.3% and deteriorated in 21.1% of total patients. There was no significan t difference between the pattern (proteinuria only, hematuria only, combination of both) and the severity of proteinuria and/or hematuria. Seventeen patients (53.1%) carried over their abnormal uri,~xy findings to the age more than 18 year5 old.

At the end of the observation period, they showed significantly higher incidence of NS and the level of blood urea nitrogen (BUN) than those without carrying over. The incidence of end-stage renal failure was 7.7% (3 patients). Fifty per cent of the patients with NS developed end-stage renal failure, and the Ievels of BUN and serum creatinine at the end of the observation period were significantly higher than those without NS. The results indicated that the presence of neptuotic syndrome was the poor prognostic factor. A long-term follow-up is continuing for these patients. Statistics of the nephrology service reveal that acute poststreptococcal glomerulonephritis (APSGN) is the most common renal disease (53%). The clinical features and course were t~ical of APSGN. The majority were 3 to 10 years old, with a peak 5 to 6 years. The sex incidence was equal. 88% presented with acute nephritis (hypertension, oedema and haematuria). Only 8% presented with nephrotic proteinuria. Impetigo was diagnosed in 89%. Most of the patients came from lower socio-economic circumstances. Acute complications (hypertensive encephalopathy, cardiac and kidney failure) developed in 18%. Most (55%) were discharged within one week (55%). Of the remainder 35% were hospitalized for 1 -2 weeks and 6,5% 2 -3 weeks. Two patients with renal failure remained in hospital for 52 and 53 days. All patients recovered. Antistreptolysin O titers was positive in 95%, antiDNASE-B and antihyaluronidase in 80%. At least one of these tests wod5 positive in every patient. Serum complement C3c showed a decrease in 91% and C4 in 24%. Although the prognosis of APSGN is good it is preventable. Improved sosio-economic standards leading to reduced skin infections and early treatment would reduce the incidence and result in considerable savings for the community and the country as a whole. We investigated 46 consecutive neonates admitted in NICU to detect renal tubular damage by estimating urinary B2 mieroglobulin (B2M) a sensitive indicator of proximal tubular injury. B2M was estimated from urine collected on day 1(D1) day 3 (D3) and whenever required on day 7 (D7) by RIA using kits supplied by Pharmacia Uppsala,Sweden. Forty full term newborns (20 each on D1 and D3) served as normal controls. Student's 't' and Mann-Whitney tests were used for statistical analysis.

Statistically significant difference was found between mean values of B2M (rag/L) when normal and sick neonates were eompared (Normal D1-1.58+0.39, D3-1.27+0.28).in sick DI-12.11+9.67, D3-10.16+11; P~.005). Analysing each etiological factor,highly-statistically significant increase in urinary B2M levels observed (P~.005) in birth asphyxia (n-9,D1-18.66+11.76, D3-15.96+13.5). Septicemia (n-8, Dl-15.41+13,D3-14.57• and renal disease (n-7,D1-14.55+ 13.6, D3-15.67+16.2). No significant increase noted withsurgical proble~ns-14 (mostly non renal congenital defects), with hyperbilirubinemia-4 and meeonium aspiration-4. 38/46 neonates received aminogiycosides which might have contributed to increase in B2M in some. B2M excretion decreased on D7 with improvement in neonate's condition.

In conclusion B2M excretion in urine is an exquisite test for deteetion of early renal tubular injury in sick neonates with birth asphyxia,sepsis and renal disease and also for followup during recovery. In primary IgA nephropathy (IgAN) an abnormal immune system response leads to increased levels of I~ directed against environmental or mesangial antigens (Ag) with formation of circulating I~ containing immune complexes (IgAIC). These findings characterize adults with IOAN and are thought to play a role in the pathogenesis of this nephropathy. Our multiconter collaborative study was devoted to investigate the relevance of these serologic abnomalitias in children affected by I~N. Seventy-seven children were studied., in 43 of them a diagnosis of IgAN was made on prevalent IgA meeangial deposits; 19 represented the control disease group (CD), including other biopsy-proven glomerulonephritis or unbiopsed idiopathic nephrotic syndrome; 15 children had a past history of urological problems without any immunological disease (U). The methods employed included the detections of IgAIC (conglutlnin and polyethylenglycol tests), IgAlfibronectin complexes, mixed IgAIIgGIC, serum IgA directed towards alimentary Ags (glIadin, glyc-glI, glutenln, ovalbumln, bovine serum albumin) and masangial Ags (fibronectin, leminln, 'type !V collagen) or polycations ( poly-L-lyslne). Mean levels of mixed I~II~IC and IgAlflbronectin were significantly increased in lOAN children vs 61) ( p<O.O I ) and U ( p<O.O01 ) groups. loAN children had mean Iovels of anti-glledin lectlnic fraction I~ signlflcantly higher than CD and U groups (p<O.02). IgAN children displayed an enhanced production of [gA reacting with autologous mesanglal matrix Ag vs CD and U groups and showed altered Inter~tion with positively charged molecules (poly-L-Lysine, p<O.O I ). This report indicate that several of the immune system ebnornlaIItias found in adults with IgAN are detectable in children affected by this din, suggesting tha t they play a role in pathogenesis of Ig~N. P-IIIA.30   IS IT POSSIBLE TO REDUCE THE INCIDENCE OF CHRONIC RENAL  FAILURE IN IgA NEPHROPATHY AND MPGN BY URINE SCREENING ?  -A MULTI-CENTER FOLLOW UP STUDY- T. Kitasawa*, T. Sakai** Dept. of Pediatrics, Nihon Univ. School of Med., Tokyo Jpn* Kidney Center, Kitasato Univ. School of'Med., Sagamihara Jpn** 241 cases of IgA nephropathy and 98 cases of MPGN were divided in to a group detected by urine screening and a group diagnosed because of nephritic symptoms. Patients in both groups were classified according to the severity of light microscopic findings. Milder glomerular change was more common in patients with IgA nephropathy and MPGN detected by urine screening while severe proliferative change was more common in patients diagnosed because of nephritic or nephroti c symptoms.

In order to determine whether it is possible to reduce the incidence of chronic renal failure by screening, a multi-center follow-up study of the above 241 cases of IgA nephropathy and 98 cases of MPGN was carried out over 4-10 years.

I14 out of 177 cases (64.4 %) detected by screening and 34 out of 64 cases (53.1%) diagnosed because of nephriti c symptoms werefree from proteinuria while one out of 177 cases (i.I %) of IgA nephropathy detected by urine screening was on dialysis while 3 out of 64 cases (4.7 %) diagnosed because of nephritic symptoms were on dialysis. According to follow up study of the patients with MPGN, 36 out of 58 cases (62.1%) detected by screening and 20 out of 40 cases (50.0 %) diagnosed because of nephritic symptoms ~a& no proteinuria while 1.7 % of cases detected bY screening and 2.5 % of cases diagnosed because of nephritic symptoms were on dialysis. This suggests that the early detection and early management of IgA nephropathy and MPGN in children by urine screening may make it possible, in some cases, to prevent deterioration of renal function and improve the prognosis. Extra-cellular matrix components (type I, III, IV, VI collagens, laminin, fibronectin) in glomeruli were stained by immunofluorescent technique in IgA nephropathy (29 cases) and in other renal diseases including minor glomerulonephritis (9 cases) and purpura nephritis (13 cases). All tested extracellular matrix components, except for type I and type III collagens, were stained in normal and pathohistologically affected glomeruli with mesangial and capillary pattern in all examined cases~ Type III collagen was stained in glomeruli with the similar pattern in other extra-cellular matrix in 7 of 29 cases of IgA nephropathy, 1 of 13 cases of purpura nephritis, but none of 9 cases of minor glomerulonephritis. All 7 type III positive cases were on the advanced stage of pathohistology. Type I collagen was not detected in any of the tested cases. Thus, it is clear that an accumulation of type III collagen in mesangium, which is possibly produced in situ, links to deterioration of IgA nephropathy. In situ detection of mRNA of type III collagen in mesangial area is ongoing in type III positive cases~ Children with AIDS in the perinatat period can develop renal disease which is often similar to that seen in adults. Host common histological The picture was that of an unusual mesangial sclerosis with associated microangiopathy. Such Lesions ere difficult to interpret and could represent either a peculiar glomerular [esion causing heavy proteinuria, which in turn was complicated by vascular disease (either intravascular coagulation or microangiopathy), or a primary defect of mesangiel and arteriole wall celts. Although some features of the present case resemble diffuse mesangiat sclerosis, such diagnosis cannot be fully justified.

It seems that a selective injury of the mesangium can be part of the spectrum of HlV-associeted nephropathy. Beta 2-microglobulin levels were measured with an ELISA in single voided urines from 859 boys and 840 girls. Their logarithm-transformed frequency distribution was skewed with a right side tailing. The upper limit of the 98% confidence interval was 660 ~tg/1 in the boys and 690 ~tg/1 in the girls. There was no significant sex-related difference. Adjustment by specific gravity was attempted but found dispensable. Of the 1699 children screened, 11 had levels above the upper limit of the 98% confidence interval. Fanally, 2 children(a boy and a girl)proved to have renal disease. Their beta 2microglobulin levels were 10,000 ktgll and 2,000 pg/1. On further examination the boy had mixed-type proteinuria and the girl unilateral renal agenesis associated with chronic renal failure. In practice, 600 ~tg/1 would serve as an actual cut-off level for both sexes with safety. We studied in vitro binding of secretory IgA1 to the glomeruli of 16 patients with IgA nephropathy. The secretory IgA1 was purified from human milk and saliva. Part of frozen sections of renal biopsy specimens were immersed overnignt at 4~ in 0.02M citrate buffer, pH 3.2. Secretory IgA1 of 1 mg/ml was applied to the non-treated or acidtreated sections. The secretory IgA1 bound to the glomeruli was examined by indirect immunofluorescence using rabbit anti-human secretory component (SC)and FITC-conjugated goat anti-rabbit IgG antisera. Similarly, glomerular IgA and SC were examined in the nontreated or acid -treated sections by immunofluorescence. Acid treatment abolished IgA immunofluorescence in only 2 patients, whereas in 11 patients IgA fluorescence did not completely disappear, and in 3 unchanged. Glomerular SC was detected in none of the sections examined, irrespective of acid treatment. Secretory IgA1 from milk was bound to the non-treated glomeruli in 14 patients including 4 with faint binding, and faintly bound to the acid-treated glomeruli in only 2. That from saliva was faintly bound to the non-treated glomemli in 6 patients, and bound to the acid-trated glomemli in none of the 16 patients studied. The results suggest that there is heterogeneity in the elution of glomerular IgA by acid and that exogenous antigens are present in the glomeruli in some of patients with IgA nephorpathy. Although the causes of SMAS and NP (left renal vein entrapment) are considered structually to be the same, simultaneous presentation of these two conditons are not well recognized. To clarify this condition, we evaluated children diagnosed to have both NP and SMAS (n=5, mean age 13y6m).

All cases were anorectic and presented emaciation with mean obesity index of -28.9%. In 4/5 cases, increased level of urobilinogen was observed accompanied with hematuria and/or proteinuria which lead to workup.

Maximum longitudinal crosssectional area of the kidney by echogram showed bigger left kidney than the right (mean 1.26x, p<O.05). Jejunal feeding was required in two cases and surgical correction was performed in one.

In all cases gaining weight normalized urinary abnormalities.

In conclusion, hematuria and/or proteinuria caused by NP can occur as a sign of SMAS. Laboratory findings leading to early diagnosis of these condition include, increased levels of urobilinogen, total bilirubin, LRV~/AO ratio and enlarged left kidney with normal echogenicity. Out of 30000 live births from 1984 to 1990, six neonates develoDed renal venous thrombosis during their first week of life. Five were unilateral and one bilateral. Predisposing risk factors were maternal diabetes in two, maternal hypertension and growth retardation in one, prenmturity and hyaline mealbrane disease in two, and birth asphyxia in one. None were treated surgical ly, two patients were treated with heparin, 25-SO/L~d<z/h for 16 to 40 days. At reevaluation, I to 5 years following the acute event, normal neurodevelopmental and physical status was found. In a11 Datients, renal fm~ction (glome.rular and tubular) were normal. In all patie~its renal imaging revealed major abnor~lities described in the 

The renal involvement ratio in HSP ranges between 20-70%. In our study, 41 patients (47.6%) with renal involvement out of 86 patients, diagnosed as HSP between January 1990 -January 1992 were included. Patients' ages varied from 4 to 14 and the mean age was 9,8. Female/. Male ratio was 19/22. Of the patients with renal involvement, 12 (29%) had mlcroseopie bematuria alone, 17 (41%) had hematuria plus proteinuria, 3 (7%) had nephritic syndrome & 9 (21%) had nephritis/nephrotie syndrome, the mean durattlon of follow-up of the 9 patieents with nephritis/nephrofie syndrome symptoms was 9 months (3-22 months) . In group of nephrltie/ nephrotle syndrome, 4 had renal biopsy. There was endo and extracapillury glomerulonephrltis (RPGN) in 2 patients, and focal neo'otiT]ng glomorulonephritis and mesenglal proliferation in 1 patient, and focal selerosing glomerulonephritls in 1 patient. All specimens showed mesengial IgA deposition on immunofluoreseent microscopic studies. Two patients with biopsy,confirmed severe crescentic glomerulonephritis and another 2 patients who fulfilled the clinical and bioehemieal criteria of RPGN were ~dmlni~tered methyl prednisolone pulse therapy & cyelophosphamlde plus dipyridamole. In 4 patients with RPGN, before treatment BUN and ereatinine levels were high (respectively 41-88, 1,5 -3 mg/dl) but decreasing to normal ranges within 3 months. Along with this, in 1 patient, urinalysis showed normal findings after 7 months. This study provides further evidence that pulse treatment in HSN presenting with RPGN may be beneficial. T, a sulfur amino acid, is an antioxidant that protects cells against oxygen free radical injury. The kidney regulates body T balance by modulating proximal reabsorption in response to altered dietary intake. There is no information about T localization in normal or diseased kidneys. Therefore, using an antibody to a taurine-glutaraldehyde-BSA conjugate, we determined T distribution in renal tissue. Normal rats (n=4), those with diabetes induced by the I.V. injection of streptozocin (STZ)(n=8), chronic puromycin aminonucleoside nephropathy (PAMN), bilateral ureteral ligation for 48 h (n=3) and 5/6 nephrectomy for ~ weeks (n=4), were studied. Normal renal tissue displayed moderate T staining in medullary tubules with minimal amounts in glomeruli and proximal tubules. STZ-diabetes and PAMN induced an increased intensity of T staining in all structures, especially medullary tubules; these changes were more prominent in diabetic rats. In STZ-diabetic rats, there was also enhanced staining of glomeruli and proximal tubules. The immunohistochemieal changes in rats with diabetic nephropathy and PAMNwere exaggerated in rats given i% T drinking waters. The models of acute and chronic renal failure did not affect renal distribution of T. The immunohistochemical studies correlated with the protective effect of T in the various disease states, i.e. T attenuated the severity of the renal structural and functional damage in rats with STZ-diabetes and PAMN in association with increased tissue staining for T. These results suggest that T is preferentially localized to medullary regions of the kidney where it protects against oxidant injury in selective disease states. Elevated rates of UAE appear to predict diabetic nephropathy in adult diabetics although the actual "pathological" cut-off has been derived retrospectively. In children the UAE rate may exceed control values yet not reach this predictive level of nephropathy. In healthy children a weak, positive correlation between age and UAE is apparent. To examine this relationship more closely, a single overnight urine sample was obtained from 888 healthy children aged 5 to 17 years (420 females, 468 males).

Albumen concentration was measured using an immuno-turbidometric method, and creatinine concentration using the standard Jaffe reaction. UAE was expressed as an excretion rate and as an alb/creat ratio, and analysed as log transformed data. Each yearly age group was compared to every other using a "t" test. This analysis revealed a mgnificant increase in UAE at 7-9 years in girls, and at 8-10 years in boys that was not seen at any other age. When expressed as an alb/creat ratio UAE did not increase. The abrupt increase in UAE that we have described coincides with the age of adrenarche and the associated BP increase seen in normal children. As serum albumen concentration and tubular reabsorption of protein do not change during this period, it might reflect an effect of increased adrenal androgen concentrations upon haemodynamic or sieving characteristics of glomerular filtration of albumen. In this study we want to compare the usual method for localisation of the site of hematuria, the microscopial demonstration of the number of dysmorphic erythrocytcs, with a new immunochemical method. The immunocytochemical slaining method to discriminate renal from non-renal hematuria, reported by Abrass and Laird for fresh urine (Am.J. Kidney Dis. 9, [44] [45] [46] [47] [48] [49] [50] 1987) was adapted. Erythrocytcs in hematuria of renal origin are coated with Tamm-Horsfall protein, in contrast to those in hematuria of non-renal origin. Following fixation on slides by ac~ton, erythrocytes in urine were stained using antiserum against Tamm-Horsfall protein. Reactions were visualised by a biotinylated second antibody, avidin and biotinylated horseradish peroxidase, producing an insoluble reaction product. In urine from kidney transplantation patients collected from the catheter localised in the pelvis 84.7% of the erythroyetcs stained by the immunoperoxidase method whereas in urine collected from the catheter localiscd in the bladder 13.1% of the erythrocytes were stained. In a group of patients with proven renal hematuria the number of dysmorphic erythrocytes were 69. 8 • 26.7% (n=32) , by the immunoperoxidase method 89.8 -+ 7.6% were stained. For samples of non-renal hematuria the number of dysmorphic erythrocytca was 15.8 _+ 12.9% (n=20) and by the immunoperoxidase method 12.4 _+ 10.5% were stained. Immunochemical staining resulted in sharper discrimination of renal and non-renal hematuria than inspection of the morphology of erythrocytes in urine. Moreover the analysis of the urine after f~xation can be postponed. Four patients with nephropathy and male pseudohermophroditism, including a pair of identical twine, were studied. All patients had female external genitalia, one with mild hypertrophy of clitoris, but showed a 46XY karyotype. Nephropathy was discovered by chance proteinuria in all patients.

So patients went into terminal renal failure while the others still have heavy protein~ria.

One patient had three consequtive biopsies, two had a biopsy and another underwent a nephrectomu

The histological findings include abundant interstitlal foam cells, mesangial matrix increase and focal segmental glomerulosclerosis. ~hese features became more prominent in the later biopsies of the patient with serial biopsies, the first biopsy having showed little abnormalities.

The histology of this nephropatly is compatible with Drash syndrome. On EM. the GBM showed complicated splitting with fine granules between the layers. The GBM of the first biopsy only showed attenuation and focal splitting while irregular thickening of the GBM with extens~re splitting was observed in the third biopsy. The tubular basement membrane also showed splitting.

We think that basement membrane abnormalities might play an important role in the nephropathy of incomplete and complete Draeh syndrome. In order to evaluate the morphologir changes induced by CSA in 17 patients (pts) who underwent HTx, we performed renal biopsies (RB) 5 to 12 months (m : 7.5) after HTx. Nine pts were less than 2 years of age and 8 were aged 2 to 13 years. All pts received oral CSA and azathioprine and steroids were given for several months in l0 pts. The morphologic changes observed on RB were classified according to the severity of tubulo-imarstitial (Tt) damage. Grade 0 was considered when there were no significant change of the renal parenchyme (5 pts). Grade I was diagnosed when a few scattered tubules with thickened basement membranes were present (7 pts). Grade II was diagnosed when biopsy showed several feel of atrophic tubules with thickened basement membranes within stripes of interstitial fibrosis (3 pts) and Grade llI when confluent or extensive areas of interstitial fibrosis with atrophic and/or collapsed tubules were observed (2 pts Our results show that TI lesions likely related to CSA may occur as early as 6 months post HTx and that, after a comparable duration of treatment, the morphologic changes may be very variable. There is apparently a relationship between the severity of TI damage and CSA dosage since pts with grades 0 and [ received lass CSA than pts with grades H and Ill. However, 1 pt with grade I received a mean dose of 748 malta 2 for 6 months, whereas 1 pt with grade Ill received 205 mg/m 2 also for 6 months. The same holds true for GFR and concenUating ability which was lower in pts with grades II and Ill as compared to pts with grades 0 and L However, GFR was decreased in 2 pts with grade I, whereas it wa~ normal in 1 pt with grade IIL At latest examination, with a mean follow-up of 3 years (range 1 l]12 yr -5 1/12 yr), none of the ctfildren had reached ESRF, but 8 pts had a decreased GFR : 1 with grade 0, 3 with grade I, 2 with grade I1 and the 2 patients with grade III. The continuation of CSA trea~nont after RB might explain these ]ong term results. Due to high risk of hepatic carcinoma the treatment of choice in tyrosinemia is early liver transplantation (Tx). However, multiple renal stones and severely impaired renal function have been reported before 1 year of age, Combined liver and renal transplantations have been made. As the enzyme -defect persists in the kidneys after liver transplantation the long term prognosis of renal function is of importance. We report renal function and histology in 6 patients with tyrssinemia 7 to 28 months (mean 19.5 months) after liver transplantation.

Diagnosis was based on low plasma fumarylacetoacetate concentration and urine excretion of succinylacetone and succinylacetoacotate (u-sue). Mean prothrombin time was 24 % (range 6-59), s-AFP 153356 1U/L (18430-246900) and n-sue excretion 33.31 mg/mmol crea (9.60-46.2) before Tx. Mean age at Tx was 1.55 yrs (0.38-2.68). After Tx the above values were 89 %, 27 IU/L and 1.65 mg/mmol crea respectively.

At tast control there was no acidosis, glucosuria or proteinuria in any patient. Serum phosphate was normal in four patients and marginally low in two. 1 patient has had tubular aminoaciduria. The mean serum ureatinine was 50 I.tmol/L (range 43-68) before Tx, [48] [49] [50] [51] [52] [53] 24 months after Tx.

Mean GFR ( 51Cr-EDTA clearance) was 87 ml/mln/l.73m 2 (range 46. 8) before Tx, 18 mo after Tx. Kidney biopsies performed on 3 patients during Tx and on 2 patients 18 mo after Tx have all shown slight dilatation oI proximal tubuli. No evidence for progressive renal damage or stones has been found.

We conclude that although renal function and morphology are abnormal in patients with tyrosinemia short -term followup after liver Tx does not sh*w severe or progressive impairment of renal function. This supports liver Tx as the treatment of choice in tyrosinemia. 6.2 (range: 4.5-9.4) . Renal function remained stable (serum creatinine 50-140 ~tmol/1). Conclusion:

Oral citrate administration lowers the risk of calcium oxalate crystallisation and appears to be clinically effective in patients with PH I. Of 594 patients with FMF aged 3-14 yrs under our care, 81 (13.6 ~) developed amyloid nephropathy (AN). The aim of the study was to evaluate parameters that would help to identify patients at risk of developing AN. For this purpose, 37 different parameters were studied by stepwise diseriminant analysis (BMDP) in the families of 85 patients with FMF. Of these, 41 had no AN, 29 had proteinuria and 15 had chronic renal failure. Results: The combination of the following parameters was found to discriminate best between the ] subgroups: Presence or absence of pancreatic involvement, paternal age (at birth of patient), sedimentation rate and intracellular (leucoeytic) alkaline phosphatase, myeloperoxidase and suecinatedehydrogenase out of attack. Linear discriminaot factors For the 3 subgroups of patients were constructed. Percent correct classification was 80 % in subgroups 1 (no AN) and 3 (renal failure), and 30 Z in subgroup 2 (proteinuria). Conclusion: Diaeriminant analysis allows to identify patients at high risk of developing AN. These are primary candidates for therapeutic trials to prevent AN. There are many causes of the nephrotic syndrome {NS). In children, minimal change is the most common cause of the nephrotic syndrome beyond the first year of life. Although it is still unclear whether FSGS is part of the spectrum of minimal change NS or a distinct entity, it is clear that there are idiopathic, exogenously induce and familial forms of FSGS. A recessive mode of transmission has been described in patients with FSGS and there are a few reports of apparently dominant transmission of FSGS.

We report a Hispanic family in which the mother and her 3 children have steroid-resistant NS. The nephrotic syndrome was first recognized in the children at the ages of 11, 13, and 16 years. The youngest has had a progressive decline in renal function over the past 2 years. The older sibling has hypertension and a slightly elevated serum creatinine. The mother and the 13 year old have proteinuria and normal blood pressure and renal function. The histological lesion in the children demonstrated varying severity of focal segmental sclerosis with mesangial proliferation and tubular atrophy. An autosomal dominant form of FSGS with variable expression is apparent in this kindred. These patients are important because of the inheritance of the condition, progressive course in some, and failure to respond to treatment. Renal histology showed diffuse glomerulosclerosis, extensive interstitial fibrosis and tubular atrophy. Case 2 was slightly nephrotic (proteinuria 1 g/day, serum albums 25 g/l), with normal GFR. Renal histology showed focal and segmental glomerulosclerosis.

In both cases, proximal tubular cells were bloated and irregularly stained. Electron microscopy showed unspecific lesions. These observations suggest that focal glomeruloaclerosis can be associated with mitochondrial encephalomyopathy. This diagnosis must be suspected when proteinuria is associated with unusual symptoms such as deafness or muscular weakness. Besides low-molecular-weight proteinuria, aminoaciduria in all g cases, phosphaturia in 5 of 6 cases, hypercalciuria in all 6 cases, and glycosuria in 2 of 8 cases were found. ~ Tubular dysfunction was more severe in the older cases.

[Pedigree B] Three cases, 2 males and one female: the propositus, one maternal uncle and a maternal grandmother.

All 3 cases had massive urinary ~-microglobulin and aminoaciduria.

None of glycosuria or phosphaturia were observed.

[Pedigree C] Two eases, 2 males: the propositus and maternal grandfather.

All two cases had massive urinary~m-microglobulin. Aminoaciduria was observed in the propositus.

None of glycosuria or phosphaturia were observed. In the screening of ALMWP including propo$itus by using urinary ~-microglobulin, 11 cases (i0 males: 1 Female) were found.

Our results suggests that ALMWP is a hereditary tubular disorder. We were surprised to note microscopic haematuria in children with cystinosis, and therefore investigated this further. Twenty-two children had urinary calcium excretion measured in 24 hour urine samples and had abdominal x-ray (AXR) and renal ultrasound scans (USS). A system of grading the severity of nephrocalcinosis was applied to the ultrasound findings. The children were aged 2. 4-14.3 (mean 7.9) years and had been treated for 1.0-12.0 (mean 5.5) years with cystine lowering agents (CL&). Treatment was intended to maintain white cell cystine (WCC) levels below 3 ~nol/mg protein, and was started at 9-100 (mean 25) months of age. Each child's average level of WCC for the duration of treatment was calculated and the mean was 4.4 (range 0.4-13.0 The cause of Fanconi Syndrome in cystinosis is enigmatic. We have previously shown that renal tubules could be loaded with cystine by incubating them with CDE, mimicking the biochemical hallmark of cystinosis.

Such tubules have impaired transport, decreased whole cell O consumption, and sub-2 strate utilization.

In this study we have further characterized the metabolic disturbances in cystine loaded renal tubule cells.

Isolated rat renal tubules were loaded with cystine by incubating them with 2mM CDE for I0 min. This had no significant effect on total ATPase, Na+K + ATPase, or the ouabain insensitive ATPase activity of renal tissue homogenates from these cystine-loaded tubules. Intracellular K was significantly lower in the cystine loaded tubules (37 vs. 47 neq/mg, p<.008). Intracellular ATP was reduced by 39% in the cystine loaded tubules (24 vs. 38 nmol/mg protein, p<.0025).

2mM CDE reduced isolated mitochondrial 02 consumption with glutamate as the substrate by 78% (3 vs. 14 natom/min/mg protein, p<.001), but had no effect on mitochondrial 02 consumption with succinate as the substrate. We speculate that the impaired transport from cystine loading with CDE is secondary to a block in mitochondrial oxidation at complex I, leading to decreased ATP formation.

The decreased ATP formation in turn reduced cellular transport. The aim of the study was to determine the trend with time of renal glomerular and tubular function in cystinotic children treated with cysteamine and to compare the value of identical parameters measured in 24 hour urine collections (UC) and the hypotonic saline loading test (HSL).

From a population of 24, 10 patients were selected in whom studies had been performed at 6 month intervals for 5 yesrs from the age of 3 years. The indices of renal glomerular and tubular function:-urine volume, creatinine clearance (CCr), fractional excretions of sodium (FENs) and potassium (FEK), were calculated using conventional formulae.

There was poor agreement between the two methods.

At 3 yesrs of age Ccr was decreased (UC 46.5 • 20.6, HSL 80.7 • 21.5 mls/min/1.73 m2) . The tendency for CCr to fall with time was not significant in UC (r = 0.4, p = 0.46) but was more marked in the HSL test (UC 43.4 + 14.5, HSL 65.2 • 22 at 8 years) .

At 3 years of age FENs was elevated (UC 3.1 + 1.7%, HSL 4.3 + 1.6%) and it fell in the HSL test to 4.1 • (p >0.6) but remained unchanged in the 24 hour urine. FEK was increased at the start of the study (UC 89.6 + 54.2%; HSL 74.9 + 43.5%) and it rose over the next 5 years to 121.6 • 76% (U~) and 82.1 • 52% (HSL). There was a strong positive correlation between FEK and age (r = 0.97, p <0.001).

Because of the poor correlation between UC snd HSL they may not be used interchsngeably to measure renal function. Glomerular and tubular function were impaired in our cystinotic patients at 3 years of age but showed only a small tendency to decline over the next 5 years during cysteamine therapy. However, the diminishing difference between the results of UC and HSL tests with time suggests a progressive loss of renal functional reserve in these patients. We report partial HPRT deficiency in a sibling. The elderbrother(9 year 10 month old) presented with acute renal faiture(ARF) and the younger one(9 year 3 month old) was asymptomatic. The index patient had been well until September 12, 1991 when ARF developed after 5 days of vomiting. On admission, he was ill looking and slightly emaciamd. BP was 90/60mmHg. Laboratory findings were'as follows : CBC 11.1-34-10900-22.6K, BUN/Set 65/7.6mg/dl, Serum uric acid 25.9mg/dl, Urine uric acid excretion(UUA)/dl GFR 6.5mg/dl GFR. Renal ultrasound showed bright echogenic kidney with mild hydronephrosis on the right. He recovered slowly but uneventfully by hydration and alkalinization. The younger brother was asymptomatic, but his serum uric acid level increased to 9.4rag/all and UUA/dl GFR was 1.3mg/dl GFR.

HPRT and APRT(adenine phosphoribosyl transferase) activities The mutation of the patient's HPRT gene was found on the exon 3 and it was a point mutation from A to G at codon 72. The younger brother had the same mutation and the mother was heterozygous for this mutation. It seems likely that partial HPRT deficiency is regarded as one of the possible causes of ARE in children(possibly more common than appreciated) and the risk of developing ARF is higher in case of dehydration. week old dd~ mice intraperitoneally every other day until killed. 50 ddy mice were divided into 2 rs. as natural course gr.(NCG) and CyA injected gr ~CyAN). At 10,17,27 and 40 weeks of age 5 ddy mice of each grs. were sacrificed At 40 weeks of age, serum IgA levebof both grs. were increased, and CD3+ and CD4+ T lymphocyteswere increased in NCG but were markedly decreased in CyAN compared to those of i0 weeks of age. In CyAN serum IgA level~ were lower than those of NCG. Histologically proliferation of mesangial cells with increased mesangial matrix were observed in both grs. but these changes were more prominant and frequent in CyAN. IF and EM findings also revealed the same results. These data suggest that decrease of CD4+ T lymphocyte may involve the inhibition of increase~ serumIgA level but it seems that serum IgA levels &o no~correla~ with the histopathologic alterations in ddy mice. Mitochondrial myopathy is a multisystemic disorder mainly involving skeletal muscle and the central nervous system but rarely cardiac muscle or the kidneys. We report three cases of this disease with renal involvement. Case 1 -aged 16 months -developed failure to thrive, mental retardation, and tremor.with a severe metabolic acidosis, like in Leigh disease. She had renal tubular dysfunction including : proximal renal tubular acidosis, hypercalciuria and excessive excretion of potassium. Biochemical investigations of the muscle biopsy revealed a defect of the complex IV of the respiratory chain. Cases 2 and 3 -both aged 6 years -developed a Kearns -Sayre syndrome with diabetes mellitus (cases 2 and 3) and pancreatic insufficiency (case 3). Renal defect associated in both cases renal tubular acidosis, phosphaturia, aminoaciduria, glucosuria, hypercalciuria and isosthenuria mimicking de Toni Debre Fanconi syndrome. Ragged-red fibers were observed in case 3 with a deletion of the mitochondrial DNA. The diagnosis of complete de Toni Debre Fanconi syndrome witi" ,chronic interstitial tubulonephritis has been described in most of the' infantile mitochondrial myopathies caused by cytochrome C oxidase deficiency (1) . In our case the expression of the proximal tubulopathy was incomplete, without aminoaciduria, phosphaturia or glucosuria. In the Kearns Syre syndrome there is usually a renal tubular involvement mimicking the Bartter syndrome (2) Gluoocorticoids (GC) can induce PKD in the differentiating kidney. Triiodothyronine (T3) appears to modify this effect. One hundred and seventy-two C57BL/6J mice (24 hours old -Day I) were treated as follows: 16J_ (n=25) injected I.M. on Day I with methylprednisolone acetate (MPA) 250mg/kg; /~ (n=24) Propylthiouracil (PTU) 0.01% in drinking water available to the nursing mothers from day 1 to day 5; (C) (n=49) MPA + PTU as given above; (D) (n=20) T 3 injected 1.25mg/kg I.P. on day 1 for 5 days; ~ (n=ll) MPA + T s as given above; _(~ (n=10) MPA + PTU + T 3 as given above; -(~l (n=33) control.

On day five the kidneys were dissected and processed for histological study to determine presence of cysts and their degree of severity.

In the group receiving MPA, the incidence of cyst formation was found to be 80%. However, no kidney cysts developed in those animals receiving either PTU or T 3 alone. In comparison to the MPA group, the incidence of cyst development (g6%) and severity was increased in those animals receiving MPA and PTU. Animals receiving MPA and T 3 were found to have a low incidence of cysts (36%) and of less severity. The final group, having received MPA + PTU + TS. showed an incidence of cysts of 60%. Animals were made hypothyroid by the PTU. Altering the thyroid status of newborn mice, modifies the ability of GC to induce cysts (incidence and severity).

This study illustrates the importance of the GC/thyroid receptor complex and its possible role in this model of PKD. In experlrnsntal ndriam~in r~phrosis (AN) protelnuria is associated ~th o 01omeruler berrier size-selectivity defect, vhich is thought to be related to 1sos of 01omorular sialoproteins resoltiN in detachment of the epithelial foot processes~ Some pothagenetical mechanisms have been extensivel~l investigated, insludinq alterations of surface electrical Charoe~ end haemodyrmmtr modifications. Conversely, no studu has considered a possible role of immunological involvement, which is likoly in AN since T-hjmphocyt~ play a pivotal role in human minimal change nephropathy presenting similar hiatolugic and proteinuric findi.~. Therefore We evaluated the role of the T-ltjmphoc~te stjstem in the development of AN. For this purpose ndriarn~in 5 r~/kg BW yes given to 50 Nude (Nu) mice, which yore divided into ;5 groups ( The RK is widely used as an experimental model of chronic renal insufficiency. Two models are used. The ligation model results in an early, severe hypertension (HT), which is unsensitive to sodium (Na) diet, sensitive to angiotensin converting enzyme inhibition (ACEI), and is associated with low PRA, but high RR. The excision model causes much milder and later HT, which is sensitive to Na diet, and unsensitive to ACEI unless dietary Na is moderately reduced (from 0.50 to 0.25%) as shown on a previous work. There are no data on PRA and RR. The aim of the study was to evaluate renin changes in the last model. Sham-operated rats (S) and uremic rats (U) (excision of 70% renal mass) received a 0.50% Na diet (SNa § UNa +) or a 0.25% Na diet (SNa-, UNa-). At week 6, blood pressure (BP) was measured by tail-cuff method. PRA was measured by RIA of Ag I using the human antibody trapping method. RR was estimated by immunofluorescence as the number of renin positive juxtaglomeralar apparatus (JGA) per 100 glomemli. PRA and RR were lower in U compared to S rats. Both were enhanced by Na reduction in the two conditions, but even under stimulation they remained lower in U rats. Conversely to the ligation model, RR was low in U rats and was detected in JGA and not in glomeruli.

In both RK models PRA is low whereas RR decreases after excision and not after Iigation. PRA and RR remain stimulable by lowering Na after excision. These data may help in understanding the different HT characteristics in the two models and hence in its mechanism. Glomerulosclerosis is a major feature in many kinds of progressive glcmerular injury leading to renal dysfunction in men. Similarly in experimental animals a variety of glomerulosclerosis were reported previously but in them mesangial matrix expansion is hardly observed. An injection of anti-Thy I antibody(ATS) induces mesanial matrix increase but it spontaneously resolves. To elucidate i~T~tnologically mediated glomerulosclerosis, we induced a model of chronic mesangial cell injury in the rat with repeated injections of ATS. ATS was raised in rabbits by in~unization with fresh thymus cells from infant rats. An intravenous injection of ATS was repeated in a week interval in 20 Lewis rats. The rats were sacrificed at 2,3,4, and 6 weeks after induction of glomerulonephritis. Light microscopy revealed mild hypercellularity(macrophage/mesangial cells) and increase of mesangial matirx at 2 and 3 weeks. A progressive increase in mesangial matrix with diffuse glomerulosclerosis was observed at 4 and 6 weeks. Serum creatinine and urea nitrogen levels increased in rats with glomerulosclerosis. Electron microscopy of rats at 6 weeks d~nonstrated a prominent rough endoplasmic reticulum in the mesangial cells and collagenous fibrills in the meangial matrix. Immunofluorescent microscopy revealed increase in type IV collagen and laminin staining in the mesangial matrix. Our findings suggested that repeated inmunologic injury to the mesangial cells results in the accumulation of extracellular matrix due to mesangial cell dysfunction and the development of glomerulosclerosis. Acute normocapnic hypoxemia is associated with a significant fall in glomerular filtration rate (GFR) and renal blood flow (RBF). The role of angiotensin II and intrarenal adenosine in the pathogenesis of the hypoxemia-induced renal changes is still controversial. Experiments were thus performed in 29 pentobarbital-anesthefized mechanically-ventilated rabbits made acutely hypoxemic. GFR and RBF were assessed by the clearance of inulin and PAH, respectively. Each animal acted as its own control. Group 1: in 8 control rabbits, acute hypoxemia significantly decreased GFR (-16_+3%), RBF (-12+3%) and filtration fraction (FF) (-4_+2%), while the renal vascular resistance (RVR) increased by 17_+4%. These changes suggest preglomerular vasoconstriction and postglomerular vasodilatation. Group 2: in 7 rabbits, the iv injection of an angiotensin converting enzyme inhibitor, perindoprilat (20 mg/kg) increased RBF (+18+4%) and decreased RVR (-14_+3%) without changing GFR.

Group 3: in 7 rabbits made acutely hypoxemic, pretreatment with perindoprilat partly prevented the changes normally induced by hypoxemia. RBF actually rose (+11-+3%) and RVR decreased (-11_+2%). The drop in GFR (-7_+2%) was significantly attenuated. These results, as well as the decrease in FF (-18_+2%), suggest that hypoxemia vasodilates the afferent and the efferent vessels when angiotensin II formation is inhibited. The role of intrarenal adenosine, a second putative mediator of the hypoxemiainduced renal changes, was further assessed in 7 hypoxemic animals (Group 4) pretreated with perindoprilat and theophylline, an antagonist of adenosine. In these animals, acute hypoxemia decreased RVR (-15_+3%) and increased RBF (+11-+2%) without affecting GFR.

These results demonstrate that both angiotensin II and intrarenal adenosine mediate the changes in intrarenal hemodynamics induced by an acute hypoxemic stress, There appeared to be qualitatively less ACE in PT in diabetes, probably explaining why less ACE is found in whole kidney homogenates.

There was qualitatively even less in PT of E or DuP animals. Vessel expression was increased in DM and normalized with therapy. Our results suggest that ACE protein distribution is altered in early diabetes mellitus and, by inference, might play a role in the early renal changes in DM. Recently several studies have raised siq~ificant concern about nephrotoxie side affects of IF in children. ~vexe tubulotoaic effects were ob-seEved. Several cases of Fanconi s~lrnle after IF were reported. In order to gain insiqht into the tecbenism of IF radiated tulmlotoxieity ~e tasted the effect of IF and its ua~or mtsbeliten (4-~H-IF, acrnlein, chloracetaldehyde) on I~A and Rl~ sFathesis, enzyae sotivitias of ~arkex enzynas of the apical and busolateral plns~a m~braaes as ceil as altochondria and endeplasaic retienl~ and on la + dependent tranport rates of I~4, l-alanlne and glucose in LLC-I~ I ceils in culture. We also tested the protective effects of the uroprotectant 2-|~rcaptoethanesulphonste (sosna) and its diaaric font dithio-bis-tercaptenthanasulpl~uste (dimsns). In an attempt to define possible |~chanises for entry of I~ and its analogues into tubular cells ~e investigated the interaction of these drnqs with ~ contralu~tinal pA~ transporter in ~ete ~istar ra.ts ~inq the sto~..flo~ capillsr~ per'fusion mt. date on 41 patients, who were observed during the acute stage of ARF are presented for periods of time ranging from 1.5-10 years. Patients were subdivided into 2 groups according to the criteria proposed by Gianantonin and based on the duration of o[igutia and/or anuria.

The following data were obtained: stata of nutrition, growth blood pressure routine hematology, proteinuda and sediment the endogenous clearance of crcafmine/GFR/, bloc~d urea, ability to concentrate urine, total blond CO2, HCO3 and pH, serum sodium and potassium. Results: 4 of 32 patient belonging to the in'st group/oligutia for less than 7 days/ had diminished GFR and slight proteinuria. 2 ef them -a reduced ability,, concentrate urine and 1 mild hyI~rtension. In 3 cases with lower GFR -abnormal state of nutrition and growth were observed. One patient of second group/n=9, oliguria for 7 -21 days er anuria less than 7 days/developed chronic renal failure and died 4 ~cars aRer acute phase of ARF, 3 other children had decreased GFR, 2 of them had also reduced concentrating capacity and slight proteinuria. One patient was hypertensive but only 4 months aRer acute stage.

In 87 per cent of children belooging to the first group and in the 55,6 per cent of patients belonging to the second group, complete recovery of renal function was finally attained. There appears to be a correlation between the severity of the acute phase ofARF and prolonged renal\involvement. Long-term folloW-tip study of patients, v~ho survived the acute stage of ARFis necessary (Pedlar Nephrol 1990 : 4,5@-61) , noted that t~lere wea an excess of HDS patients with weak or absent e~orassion of the erythr~ PI antigen (Pla). Verocytotoxts requires the terminal disaccharide of Pla to bind to cells. Thi's group po~%ulated that PI positivity may be protective (toxin bot~nd to ẽ but latter not d~ed because not synthesizing protein), and PI negativity a risk renter in HUS (increased toxin hotrod to vulnerable nucleated endothelial cells). We therefore investigated HUS patients (= 21) for P1 status end whether this affected renal fenction outcome if follcmed for at least 6 nmnths, and groups of blank African = 36 and caucasian : 41 paediatric renal patients without HUS, and adult blood donors : bleck = 197 and caucasian = 157. In both the blood donors and r~ paed. renal patients, the blanks have significantly greater Pla positivity, which may be a factor in protecting them from HWS. This may occur with the erytkLroczrte bound toxin being cleared in the reticule-endothelial system. Other possible factors such as differing HIA antigens and verocytetoxin antibodies were not addressed in this study. Changes in erythrocyte lipid peroxidation (measured as the concentration of malonyl dialdehyde, MDA), glutathione (GSH) metabolism, antioxidant enzyme activities (glutathione peroxidase, l;P-ase; catalase and superoxide dysmutase SOD), haemoglobin (Hb) metabolites (met Hb, carboxy Hb COHb), the in vitro effect of hydrogen peroxide induced haemolysis (acetylphenylhydrazine APH test) were studied in six children with atypical haemolytic uraemic syndrome (HUS) (age 6.7+4.1 years ~+SO) and six age-and sex--matched contr#is. The level of MDA was significantly higher and eatalase activity was lower in the whole blood haemolysates than in the controls (p-' 0.05). SO0 and OR-ass activity were normal. Oxidized GSH (GSSG) concentration was significantly higher in the patients than in the controls (26. 2!4.2-, 10 .9~1.8 nM/g Hb respectively). The percentages of earboxy Hb and met Hb were higher also in HUS (5.2+ 0.2-, 2.8!0.3%) than in the controls (p< 0.01) GSH-stability was lower. Incubation of ROCs for 1 h with APH induced a more pronounced decrease in the concentration of GSH (p,L O.OOl), and an increase in oxidized products of Hb, met Hb and haemichrome (p/ O.OOl), but only in HUS patients. We also observed that these results returned to normal after clinical recovery. Oxidative damage has an important role in the pathogenesis of HUS. Gubler et al [Ann P6diatr (Paris) 1990, 37 : 78-82] . We report a patient with similar findings. Parents were healthy and were apparently not cousins. Family history was marked by a severe jaundice and neonatal death of their first two children. The third child had severe jaundice due to an hemolytic syndrome and was treated with 4 exchange-transfusions in the first 6 days of life. Microscopic hematuria and Transient mild renal failure were observed during this p6riod. Between the age of 4 to 10 years, he was followed in an outpatient clinic for splenomegaly, chronic hemolytic anemia and thrombopenia. Hematological investigation failed to find the cause of hemolysis but fragmented erythrocytes were observed. He developed proteinuria at the age of 8, mild hypertension at 9, and chronic renal failure at 1O years. Renal biopsy, performed at 10 years, showed thickened and split capillary walls. Hemodialysis was performed from the age of t4. The onset of dialysis was marked by uncontrolled hypertension, severe attacks of thrombopenia and hemolytic anemia necessitating blood transfusion in spite of erythropoietin injections. Bilateral nephrectomy, performed 2 months after the onset of dialysis, resulted in a stable level of hemoglobin, normal platelet count, disappearance of fragmented circulating erythrocytes and normal blood pressure without any antihypertensive drugs. Electron microscopic study of a renal fragment stained with phosphotungstic acid disclosed numerous bundles of interstitial collagen fibrils in the mesangial matrix and the glomerular basement membrane as described in the Nail-Patella syndrome nephropathy. This boy had unilateral lobster claw in place of the left hand. Bilateral patella were in normal place and he had no fingernails dysplasia, no iliac horns and no webbing at the elbow joints.

In conclusion, 1) Chronic HUS with neonatal onset was associated with ultrastructural renal lesions of the Nail-Patella nephropathy without classic bone abnormalities, 2) Disappearance of the hematological patterns of HUS after bilateral nephrectomy suggests that they were not induced by an unknown humoral factor, a primitive disorder of platelet function or coagulation, 3) Family history suggests autosomal recessive mode of inheritance. Acute renal failure (ARF) in infancy and childhood is associated with a mortality ranging from 11% to 61% in various series. This study aimed at analyzing the factors that affected the outcome of 46 children with ARF, presenting over a 5 year period te the Department of Paediatrics, NUS. There were 32 boys and 14 gifts, with ages ranging from 0-18 years (mean 4.6 + 4.6 years). Mortality in this series was 41.3%. Causes of ARF included acute tubular necrosis (ATN) (58.7%), glomer-nephritis (32.6%), obstractive uropathy (6.5%) and hemolytic-uremic syndrome (2.2%). A multivariate discriminant analysis considering mortality as a dependent variable was performed with the following variables: sex, race, age, aetiology, oliguria, hypotension, fits, blood urea, serum creatinine, disseminated intravaseular coagulopathy (DIVC), assisted ventilation (VENT) and need for dialysis. Using the multiple linear regression model, three factors were found to be independently significant in determining outcome with a discriminant score (Y) as follows: Y = 0.228*(ATN) + 0.453*(DIVC) + 0.373*(VENT)

The muitiple correlation coefficient (r) was 0.87 and the multiple coefficient of determination (r 2) was 0.76. When a discriminant score of 0.7 was used as cutoff to predict mortality, a positive predictive value of 100% and sensitivity of 57% was obtained. In summary, the presence of ATN, DIVC and the need for ventilation were of prognostic significance in children with ARF, and a regression equation could be used to predict outcome. 

HD is high. Ve have tried to establish an early prognosis in these patients, analyzing the prospective collected data of 100 cases. Median age was 6 m., 72 underwent surgery before ARF and overall mortality was 50%, Unlvarlate analysis was used to assesSthe importa~ ce of Presence or absence of the variables were scored as 1 or 0 respectively. For PD .8 mortality was 87%, We think this in easy score to predict mortality in these patients. 

Children's Hospital, Heidelberg University, Im Neuenheimer Feld 150, D-6900 Heidelberg,

Glucose intolerance is common in acute renal failure (ARF). Insulin is often required during total parenteral nutrition of patients with ARF but resistance to its hypoglyeemic effect is often seen. The effect of IGF l in ARF is unknown. Male sprague dawley rats (200 gm) underwent either bilateral ureteric ligation (ARF model) or control (C) sham operation. Chronic vascular catheters were inserted into all animals and they were studied 36 hours post-operatively in the conscious 18-hr fasted state. Rats with ARF had higher serum ereatinine (4.2• mg/dl Vs 0.2• p<0.001), higher serum glucose (152• mg/dl Vs 128• p<O.02) and lower arterial pH (7.15• Vs 7.35• p<O.02 ) than C rats (N=24 in each group). ARF and C rats received IGF l infusion at 5 ~g/kg/min. Both groups also received insulin infusion at 1.4 mU/kg/mln. The time (TI/2) taken to reach serum glucose concentrations 50% of the fasting levels was assessed in each group (N=6). TI/2 was not different between ARF (59• min) and C rats (49• during IGF l but longer in ARF (89• than C (41• rats during insulin infusion. Total body glucose uptake (I mg/kg.min) during IGF 1 euglyeemic clamps (7 pg/kg.min) was not different between ARF (12.5• and C rats (16.2• I during equipotent insulin euglycemic clamps was lower in ARF (3.4• than C rats (12.3• p<O.O01) . Hepatic glucose production (H mg/kg.mln) measured by tritiated glucose turnover was not suppressed by IGF! and not different between ARF and C rats.

H was suppressed by insulin but not different between ARF and C rats. Thus rats with ARF are sensitive to the hypoglycemie effect of IGFI but are resistant to that of insulin. IGF t may be more useful than insulin in overcoming glucose intolerance during total parenteral nutrition of patients with ARF. There were 55 boys and 25 girls; 60% were below 2 years of age.

Acute, usually severe dysentery was the prodromal illness in 80%. Most patients had severe renal involvement with anuria in 60% and oliguria in Z0%.

Coagulation abnerrealities were seen in 24 of 30 cases.

Siool culture shewed Shigeila in 7 cases and non-typheidal Salmonella in g; none of the cases showed verotoxin producing E. co]& (VTEC). ELISA was used to detect anti-lipopolysaceharide anti-bodies (LPS ab) in patient's sera to VTEC and shi~e]la dysenteriae 01.

Anti-LPS ab te E.eoli 026, 157 and S.dysenteriae were deteclmd in 9,2 and 2 cases respectively; in 6 additional cases LPS ab were detecimd against more than one strain.

Renal biopsy showed cortical necrosis in 40% cases. The mortality was 55%, chiefly related te duration and severity of renal failure.

Our observations indicate that HUS in these children is mostly related to dysentery, likely to be sh~'ellosis or infection with VTEC, and is usually associatmd with severe renal damage and high mortality. Little information is available on risk factors for childhood HUS. This case control study enrolled 34 consecutive patients (pts) with HUS at 7 Canadian centres during the summer of 1990. HUS pts were compared with 102 healthy controls identified from the Emergency Rooms (El{) of the 7 centres.

A risk factor questionnaire was administered to the parents of both HUS cases and ER controls.

All 34 with HUS had diarrhea (29 had bloody stools); 13 male, 21 female. HUS pts and controls had similar rates of exposure to ground meat. Of those who had eaten ground meat in the 2 weeks before, HUS pts were marginally more likely to have eaten meat that appeared pink (5/21 vs 7/92; p < .05). More HUS pts than ER controls reported exposure to a family member or non-family contact with gastroenteritis (25/34 vs 29/102; p<.00001; OR 7.0 {95% CI, 2.7-18.5}). The HUS pts and ER controls did not differ on methods of preparing and handling meat at home or on exposure to animals, raw milk, raw eggs or fast food restaurants.

We conclude that person-to-person spread of enteric pathogens is an important factor for an individual child's risk of developing HUS. In order to avoid underestimating the true importance of food risk factors for HUS, this study emphasizes the need to assess the food exposure history of the index case of gastroenteritis within a family. ACE inhibitors have been considered usefull to decrease progression in chronic renal failure. We evaluated enalapril treatment in 25 patients (16 girls and 9 boys) with persistent proteinuria after a HUS with severe acute renal failure, at a mean age of 16.4 months (r: 5 -70). Renal sonogra phy in 19 children showed in fifteen, abnormal parench~al structure and, or decreased renal size. All patients were followed during 22.5 months (r : 5 -70) with controlled protein intake for RDA and sodium dietary restriction. Later with the same dietary conditions and enalapril therapy (0.18 mg/kg/daily, r: 0.08 -0.40) during 20.62 months (r: 4 -60). Proteinuri~ decreased from 65.55 + 10.8 to 10.15 + 2.2 mg/m2/ hour (mean + 5EH) (P< 0.001) aft~ enalapril treatment while creatinine ~learance was 80.04 + 5.IB before and 87.9 + 5.68 ml/min per 1.73 m 2 after medication. This average fa~of protein urinary excretion was 79.95% ( r: 28 -100 ). Conclusions: I) Enalapril therapy associated with controlled protein intake for RDA and mild sodium dietary restriction has been useful in decreasing proteinuria excretion; 2) Renal function measured by creatinine clearance was preserved during the period of treatment. PMNLs are implicated in the pathogenesis of D+ HUS. At presentation the PMNL count is elevated and high values predict poor outcome. PMNL activation is reflected by raised al-antitrysin (aI-AT) bound elastase. We investigated possible mechanisms of activation by measuring cytokines IL-8 and tumour necrosis factor u (TNF u) plus anti-neutrophil cytoplasmic antibodies (ANCA). TNF u levels were raised in 1 of 16 D+ HUB children but in no patients were ANCA detected. Serum IL-8 levels were significantly elevated in D+ n=25; n=9; p<0.05 ); compared with controls 10.7 (5.4-19, n=17) (geometric mean pg/ml, observed range). Children with elevated PMNL counts due to other causes also had raised n=15; p<O.001 ), but in renal failure levels were only slightly increased: 15.1 (1-130, n=10; p<0.05) . In D+ HUS serum IL-8 levels at presentation correlated with the PMNL count (r=0.73, p<0.001) and the three highest counts were seen in children who died in the acute phase. IL-8 levels returned to normal within 48-72hr of admission before the PMNL count fell. The data suggest that in D+ HUS PMNLs are recruited by IL-8 and that serum IL-8 levels predict disease severity, Between 1980 and 1991 136 patients with D+ HUS were admitted to the HSC,GOS, 19 (14%) of whom had central nervous system involvement. There were i0 M and 9 F, with a median age of 2.5 yr; range i-ii.i, and median polymorphonuclear leucocyte count at presentation of 23.3 xlog/l; range 9.6-45.3. 14 had convulsions, 12 were ventilated and all required dialysis for renal failure. 13 were treated with plasma exchange receiving a median of 6 plasma volume x 2exchanges (range 1-13) and I0 received a prostacyclin infusion (3-15 ng/kg/min). Eieetroencephalograms (EEGs) were performed on 16 and all were abnormal with changes consistent with encephalopathy. 12 had CT brain scans; 5 of which were reported as normal, 5 showed signs of cerebral oedema and 2 evidence of cerebral infarction. 6 also had single photon emission computerised tomograms (SPECT) of the brain using HMPAO labelled to technetium ; 2 studies were reported as normal, 3 showed areas of reduced cerebral perfusion and 1 was a technical failure. 8 of 19 (42%) patients died, 6 with cerebral and gastrointestinal complications and 2 with severe pseudomembranous ischaemic proctocolitis.

Of the remaining ii, 3 have neurological and nephrological sequelae, 2 have residual carbohydrate intolerance , 1 has significant proteinuria and a reduced GFR and 5 currently have no evidence of nephropathy. The introduction of non invasive cerebral perfusion studies and the continuing use of neurophysiological assessment-may help to provide a basis for a clearer understanding of the pathophysiology and prognosis of this aggressive disorder. Two cases of perinatal oligo-anuric renal failure are presented.

Features included oligohydrsmnios, unexplained hypotens• elevated renin persisting after volume expansion, and normal aldosterone levels. Case I was refractory to angiotensin II (AII) infusion, but blood pressure (BP) rose after AII with indomethacin.

Case 2 increased BP and urine output with AII. This child had a markedly elevated plasma renin enzyme concentration with low substrate. Pituitary adrenal axis was normal. Both children had normal renal ultrasound scans with normal arterial flow.

Renal histology was normal in both, with the exception of some srteri01ar narrowing in Case 2. DMSA scans revealed poor uptake in both children.

Case I Was dialysed for 8 weeks and treatment then withdrawn. Case 2 was treated with frusemide and saline supplementation for 2 weeks. During this time her renal function slowly improved. A mild renal tubular acidosis and hyperkalsemia persisted. We note that Case 2 had a single sibling who died in the perinatal period with external features of Potter's Syndrome. Postmortem revealed hypoplastic lungs but normal kidneys. The regulation of glomerular filtration rate in the newborn is critically dependent upon efferent arteriolar tone. We hypothesize that these two infants with structurally nor~nal kidneys developed renal failure as a result of primary disturbances of renal vascular sutoregulation involving the RAS. Lipid peroxldation in blood plasma, which plays a role in the pathngenesls of HUS and c~-toceferol plasma concentration, was studied in various studies of HUS. The acute period of discase is marked by an increased malonildialdehyde (IVIDA) level. Its level decreased after hcmodialysis, but was still much higher than the norm. The high level of MDA was preserved even after recovery. In the course of a long follow-up, this index returned to normal, but in cases with proteinurla it remained very high. The concentration of lipid pero~dation intermediate products also underwent certain changes. The increase of dien conjugate was espedally marked during all observation periods. As it was mentioned in other publications, the concentration of vitamin E in blood plasma decreases. At the same time our observations show that during an acute period of disease (before treatment) this level i~ increased and is especialiy high in severe forms of the disease. In a dynamic phase during treatment its concentration decreased below the norm. In the course of long term follow-up, we have noticed authentically increased vitamin E levels in the plasma (which correlated with an increased level of MDA).

A.Trivelli,F.Ginevri,G.Fabbrett.______i,A.Muttie,E-Bergamasehi~ P-AItieri,. G.M.Ghi~er___~,F.Perfumo,R.Gusmano Dep.ts of Nephrolo~ and Pathology, G.Gaslini Institute, Genoa and Lab. of Industrial Toxicology, Univ. of Parma.

This study was planned to define the participation of tubulo-interstitial (TI) fibrosis in the progression of chronic adriamycin (~DR) nephropathy and the role of proteinuria as a determinant of fibrosis in this model.Chronic ADR nephropathy was induced by 2 ADR (2 mg/kg)doses in 18 Sprague Dawley rats part of which were assigned to weekly i.e. cyclophosphamide (50 mg/kg)to induce mild leukopenia (ADR-cy).Monthly evaluation of the renal function was performed by Iothalamate (GFR) and PAH (P~PF) clearances; urinary proteins were simultaneously evaluated by:a)speeific ELISA for rat albumin and RBP; b)B-glucosidase by a fluorimetrie assay;c)2-D eleetrophoresis. Marked TI infiltration by CD4 + lymphoeytes and diffuse TI fibrosis were the salient features at week 8 and 16 in ADR rats,which also_~resented a 50~ reduction of GFR ( Tubulo-Interstitial (TI) fibrosis is the hallmark of many human and experimental nephropathies being also strictly correlated with declining GFR. We used immunofluorescence to characterize the composition of extracellular matrix in experimental TI fibrosis;in situ hybridization and studies with cells in culture were utilized for defining the cell origin of extracellular matrix proteins. Experimental TI fibrosis was induced in 9 Sprague Dawley rats by 2 adriamycin(ADR)doses,which were sacrificed after 4 months when they had developed renal insufficiency (Iothalamate CI. reduced by 50%). At this time all ADR rats presented marked TI infiltration by CD4 + lymphocytes and diffuse fibrosis which was positive to anti-col III and anti-col V antibodies while col I and col IV were absent. In situ hybridization employing a 27 bp oligonucleotide specific for the 5' UTR region of ~oi III confirmed the diffuese deposition of col IIl within the tubulo-interstitium and excluded any direct participation of tubular epithelial cells in the formation of these deposits. Further studies were then performed with cultured cells in vitro to exclude the origin of sol llI from epithelial cells. In such conditions renal fibroblasts but not tubular epithelia were stimulated to synthesize collagen (+40% SH proline incorporation) by conditioned media obtained from rats with severe TI fibrosis. We conclude that col IIl is the major component of TI deposits in ADR experimental fibrosis. Interstitial fibroblasts but not tubular epithelial cells represent the site of synthesis of col III,and are responsible for TI fibrosis. Further studies on the regulation of col III synthesis by renal fibroblasts are essential to understand the mechanisms responsible of TI fibrosis in experimental models of the disease. 

Acute paracetamol (Acetaminophen; N-acetyl-p-8minophenol) intoxication presents not only a liver, but also a kidney hazard. We describe a 14 year old girl who arrived at the hospital 18 hrs. after ingestion of 15g of paracebemol. Serum level of paraeetamol was 73 mg/ml (in the "hepatotoxic range" related to time delay). No specific antidote was administered according to the toxicology center. Hepatotoxicity and a non oliguric acute renal failure (A.R.F.) developed 24 hrs. after ingestion. The hepatotoxicity was characterized by a raise in liver enzymes up to: SGOT 5,000 U/L (normal = 120-370 U/L) and slight h~perbilirubinemia: 1.5 mg~ (normal N 1.0 mg~). There were no signs of liver failure or encephalopathy. During the following 2 days, renal function deteriorated. Serum creatinine and urea levels raised to 7 mg~ and 200 mg~, respectively. Creatinine clearance of 16 ml/min and urine volume of 2,000-2,500 ml/2C~h were noted. Urinalysis revealed many brown granular casts. Liver enzymes returned to normal values after 14 days and kidney function became normal afber one month.

A similar course of paracetamol induced A.E.F. with spontaneous remission not related to liver failure has not been described to the best of our knowledge. In spite of its rarity, A.R.F. should be looked for in each case of paracets~ol overdose.

Glucose intolerance and insulin resistance are common complications of anemic states such as end-stage renal disease and thalassemia major. Iron overload has been proposed as a pathogenetis factor of glucose intolerance and insulin resistance in thalassemia major. 8 hemodialysis adolescents (18 • 1 yr)W~c~ treated with human recombinant erythropoietin (EPO) therapy (mean dose 70 units/kg) for 9 months for correction of their anemia. Hematocrit increased from 22.7 • 1.8 % to 32.7 • 1.5 (P < 0.01). Ferritin decreased from 1508 • 358 ~g/dl to 800 • 153; serum iron from 143 • 13 pg/dl to 89 • I0; and % saturation from 58 • 6 % to 40 • 4 (P < 0.02 in all cases).

There were no significant changes in weight, height, blood pressure, calorie intake, tricep skinfold thickness or arm muscular area. There were also no significant changes in serum calcium, phosphate, bicarbonate, albumin, creatinlne or blood urea nitrogen. Glucose tolerance was assessed by intravenous glucose tolerance tests and insulin sensitivity was assessed by euglycemic clamp technique (at 4 mU/kg/min insulin infusion rate) in the patients before and after correction of anemia by EPO and compared with 8 healthy controls (19 • 1 yr). During intravenous glucose tolerance tests, the K values (slope of log serum glucose decay curve) were lower in patients (i.01 • 0.i0) before treatment than controls (1.65 i 0.15; P < 0.02). K values in patients increased by 55% (P < 0.01) after EPO therapy to 1.56 • 0.18 (not different from controls). During euglycemic clamps, insulin sensitivity was lower in the patients before treatment (6.75 • 1.02 mg/kg/min) compared with controls (12.15 Z 1.28). Insulin sensitivity increased by 46% (P < 0.01) in patients following EPO therapy to 10.04 • 1.04 (not different from controls). Thus following correction of anemia and amelioration of iron overload by EPO therapy, glucose intolerance and insulin resistance were reversed in hemodialysis patients. Eight children (mean age 12.2 yrs) being on regular dialysis (7 HD, 1 CAPD) were treated by recombinant human erythropoietin (Eprex R, Cilag AG) iv. or sc. 2-3 times a week. All patients were strongly transfusion-dependent. The initial dose of 160 U/kg/week was gradually increased to 400 U/kg/weekduring the first six weeks. The haematocrit level (Htc) rose from O. 18 to 0.33 (target Htc) by the 10-12. weeks. A dose of 250-300 U/kg/week was required to maintain the target Htc. Since the third week of Eprex a treatment no further blood transfusions were necessary. At the third month of treatmnet a close linear correlation could be observed between the Eprex R dosage and the reticulocyte (Rtc) count (r=0.88), while the Htc level failed to show a similar correlation. Consequently the Rtc count revailed to be a more sensible indicator of the actual dosage of erythropoietin than the Htc. None of the main potential hazards (seisures, hypertensive encephalopathy, clotting problems) occured during the t{eatment. The Iong-lierm efficacy of hemodialysis characterized by the mean serum creatinine remained unchanged. Several allergic reactions could be noticed as side effects: frequent eosinophiIia and one case of "flu-like" syndrome, All of our treated patients have shown-,a substantial improvement in the quality of life with increased appetite, body-weight and physical activity. The only child having a very high level of cytotoxic antibodies (95%) presented a considerable fall to 20% within 14 month of treatment, According to this data treatment with Eprex R is a safe and effective therapy of the anaemia of children with chronic renal failure on regular dialysis. The long-term (5-24 me, mean 15 mo) safety and efficacy of rhEPO in the treatment of the anemia of CRF was prospectively studied in 34 children (age:0.2-17.5 yr). 12 patients (pt) were on hemodialysis (HD), 14 pt were on chronic cycling peritoneal dialysis (CCPD) and 8 were predialysis (Pre-D) with CRCI-25• ml/min/l.73 m 2, Therapy was initiated with 50 U/kg once a week and adjusted according to response. was achieved by week 8 in CCPD and pre-D (SC route, 2X/wk) and by 14 weeks in HD (IV route, 3X/wk). Transfusion (Tx) requirements decreased from 1.2 and 0.75 tx/pt-m 0 prior to rhEPO to 0.12 and 0 tx/pt-mo in HD and CCPD, respectively. Ferritin levels decreased by 75% in II patients with iron overload. 6 patients (2 CCPD and 4 HD) required intravenous iron administration to elicit a hemopoietic response. Circulating lymphocytotoxic antibodies decreased by 45% in 8 pt with high titers; two pts were successfully transplanted. The incidence of clotted A-V accesses was 0.21/ pt-mo with rhEPO (vs 0.08 prior to rhEPO, p<O.05). There was no change in the freq-uency of hyperkalemic, hypertensive or epileptic episodes. None of the pt developed de novo hypertension. 2 pre-D pt started dialysis @ 12 and 48 wks of treatment. There was no significant change in caloric intake or cardiac function. Response to rhEP0 was affected by infection (r=-0.542, p<0.02), Fe deficiency (r=0.763, p<0.01) and PTH levels (r=-0.879. p<0.001). We conclude that rhEP0 is a safe and efficacious alternative to frequent transfusions in children, with resultant decrease in hypersensitization rates and consequent successful transplantation.

P-IVA. 7 It has been suggested from animal studies that correction of renal anemia by EPO accelerates glomerular injury, probably by glomerular capillary hypertension. Although short-term studies of adult predialysis patients treated by EPO showed a stable GFR it is unknown if in the long-run renal function deteriorates faster than expected. We have treated 11 anemic children with PRF aged 0.6-17.2 years (Hb 6.3-9.3 g/dl, serum creatinine=SCR 1.1-7.7 , mean 4.4 mg/dl) by subcutaneous erythropoietin (ClLAG) given once per week for periods of 11-95 (mean 56) weeks (in 6 pts up to end stage). Hematologic parameters, SCR and growth were regularly checked. After a correction dose of 150 U/kg/wk Hb increased by 2 g/dl in 2-8 (mean 6.6) wks except in one child who was severely iron deficient. The Hb target level of 11.5-13.5 g/dl was reached in 18-203 days and was maintained by dose adaptation. At last observation mean maintenance dose was 130 (80-300) u]kg/wk and mean SCR 6.5 mg]dl. Serum ferriUn levels declined in all pts despite iron supplementation. Blood pressure increased in 3 pts by >20 mmHg and antihypertensive medication was intensified in 4 pts whilst 6 needed no antihypertensive drugs. The change of renal function was assessed by serial SCR measurements in 7 children followed for > 300 days before and after start of EPO. The slope of the regression line of 1/SCR values did not change significantly (p < 0.75). One child (SCR 5.4 mg/dl at start of EPO) developed severe hypertension and deteriorated rapidly reaching ESRD after 5 mos. Mean SDS score of body height did not change significantly after EPO The best timing of rhEPO application is still under debate up to now. To elucidate whether a s.c. treatment 3 times per week is superior to a procedure performed once per week, we have treated 22 pediatric patients with preterminal renal failure (age 0.3-17.0, mean 6.2 yrs, Scr 1.3-13.6, mean 4.4 mg/dl) in a prospective randomized multi-centre study. 10 patients (mean Hb 8.5 g/dl) received rhEPO (ERYPO, CILAG) s.c. in a dosage of 50 U/kg three times per week (group 3x) and 12 patients (mean Hb 7.9 g/dl) of 150 U/kg once per week (group Ix). 4 patients were excluded from the analysis: non-response due to severe intractable infection (1), transplantation (1), dialysis (1), non-compliance (1). The response intervals (increase of Hb>2.0 g/dl) did not significantly differ between both groups and amounted to 6 weeks in group 3x (n=7) and 8 weeks in group Ix (n= 11) with corresponding weekly doses of 129 and 131 U/kg respectively. The correction intervals (Hb> 11.5 g/dl), however, significantly differed from each other with 9.3 weeks in group 3x and 15.6 weeks in group Ix (p<0.01) by means of comparable correction doses of 135 und 158 U/kg /week, respectively. The sustaining doses did not significantly differ between both groups (103 vs 111 U/kg / week). Side effects were only rather limited and equally distributed between both ~roups never indicating a deterioration of glomerular filtrat:on rate. 1/Scr changed from 0.238 to 0.198 in group 3x and from 0.354 to 0.396 in group Ix. Differences in blood pressure behaviour could not be detected. Data suggest that the shorter correction interval in group 3x will easily be overcome by the burdens and costs of a s.c.-injection three tt~es per week so that routine rhEPO application once per weel~ should be preferred especially in children, if there is no reed for a rapid correction otanemta. Up to now in children with terminal renal failure no amelioration of growth rate was observed under treatment with rhEPO leading only to subphysiologieal Hb blood concentrations. In a prospective multi-centre study we therefore investigated the effect of rhEPO (ERYPO, C1LAG) in children with PTRF achieving normal Hb concentrations (target range 11.5 -13.5 g/dl). Treatment was started in 20 patients with 150 U/kg rhEPO s.e./wk. 4 patients dropped out of the study because of non-response, start of dialysis, transplantation and non-compliance. In the remaining 16 patients (mean age 6.3 yrs, mean Hb 8.1 g/dl, mean Scr 3.8 mg/dl) body length had changed within the last 6 months period before rhEPO treatment from t08.3 to 110.4 cm and increased to t14.2 cm after 6 months of treatment. Growth velocity increased from 4.65 +/-2.82 to 7.59 +/-5.92 cm/yr with a Z-score normalizing from -2.35 to + 0.08 ( p < 0.001 ). When restricting the analysis to prepubertal children ( N = t2 ) a comparable increase of Z-score from -2.79 to + 0.17 was detected, The individual analysis revealed a better growth under rhEPO in 13/16 pts with 7 pts leveling up with their Z-score in the positive range. Bone age was not unduly accelerated. For the first time these data suggest that growth of children with PTRF can be significantly ameliorated and even normalized in most cases by rhEPO administration leading to physiologic Hb levels, but a longer observation period is necessary for definite conclusions. R-HuEPO was administered to seven children (6 boys and 1 girl) aged 1,5 to 13,2 years (mean age 7,7 years) with pre-dialysis Chronic Renal Failure (mean serum ereatinine 3,96~1,45 mg/dl) and normochromic and normocytic anemia (mean Hb 7,7~i,08 gr/dl mean Ht 0,23~0,03). All children were normotensive. R-HuEPO was administered subcutaneously three times weekly at a mean dose of 50 U/Kg per injection during the first month(correction ph~ se). Subsequently the dose was modified according to Hb and Ht levels(maintenance phase).Mean follow-up was 9 months(2 months -2 years). At the end of the correction phase all children obtained the target levels of Hb and Ht (9,91• gr/dl,p<0,001; 0,30~0,02,p=0,001 ). An increase in reticulocyte counts was seen already within one week of the r-HuEPO treatment. In the m~ intenance phase the dosage of r-HuEPO was decreased at twice s week in a child and it was doubled in another one; it was unchanged in the remaining. There was no difference in the serum potassium and phosphorus levels before and during the treutment. The mean ereatinine serum level showed a significant increase at the end of the study (6,88~2,53 mg/dl, p=0,001) . Non changes in blood pressure levels were recorded. As side effect a flu-like syndrome was seen in two children following the fi~ st injection of r-HuEPO. Our results suggest that r-HuEPO is safe and effective in pre-dialysis children without adverse ef fects on blood pressure and serum potassium. There was a signi ficant decrease of renal function, but we found no difference in slopes between the pre-treatment and post-treatment periods with respect to the inverse of the creatinine levels. In 8 children on dialysis therapy we have studied the in vivo response to rhEPO, as well as the in vitro characteristics of their BM and circulating erythroid and granulomonocytic progenitors (BFU-E and GM-CFC, respectively), including BFU-E response to low concentrations of rhEPO. In addition, the possible presence of inhibitory factors to erythropoiesis in the patients' serum or conditioned medium (CM) produced by their mononuclear cells was evaluated. Patients were studied before, 1 and 4 weeks and 4 months following rhEPO therapy. All patients responded to the administration of rhEPO with a marked amelioration of their anemia. Prior to rbEPO therapy, BM and circulating BFU-E in RRT patients were 1.8-2.2 times greater than in 8 age-matched healthy controls, and significantly more responsive (2.5-2.6 fold) to low (1/10 to 1/2 of the optimal) concentrations of rhEPO than cells from the controls subjects. Four weeks following rhEPO therapy the increase in the number of BFU-E and the increased sensitivity of rhEPO returned to normal. Addition of patients' serum and CM (10%) to cultures of normal BFU-E and GM-CFC targets, did not inhibit their colony numbers. BM and circulating GM-CFCs frequencies were comparable to those of the controls, prior to and following rhEPO therapy.

These results demonstrate unique characteristics of circulating BFU-E in children on RRT, namely abundant numbers and increased responsiveness to rhEPO, both returning to normal values following rhEPO therapy. In children on RRT no serum or cellular-produced inhibitory factors were found and the patients' GM-CFCs numbers were not influenced by rKEPO therapy. Treatment with rHuEpo can eliminate many symptoms that had been atm~outed to uremia. Repetitive punctures in children undergoing three times weekly SC rHuEpe can result in noncompliance with the therapeutic regimen. The aim of this study was to evaluate the efficaoj of once weekly SC injection of rHuEpo in children with ESRD on CAPD. Six children (5 males, 1 female, mean-age: 6.0 years, range: 0.5 to 15.8 years) with ESRD on CAPD were treated with a regimen of rHuEpo 150 U/Kg/week SC for i2 weeks. All patients received oral iron supplementation. All children improved appetite and well-being. The adolescents showed an increase ability to engage in regular activities. The hematocrit increased from 20.3 +-. 1.2% to 31.7 +-3.8% in 12 weeks. The mean weekly increase in hematoerit was 0.95 -* 0.34%. There was no significant differences in iron indices prior and during rHuEPO treatment. 

Side effects related to rHuEpo included transient pain at the site of injection in all, pruritus at the site of injection .in 1 child, hyperphosphatemia in 1 infant, iron relative deficiency in 2 childien and asymptomatic increase in blood pressure in one hypertensive child. Any of the 5 normotensive patients developed hypertension. We concluded that once weekly 150U/kg SC rHuEpo is effective in correcting anemia in children on CAPD. This regimen results in few side effects, decreases the cost of treatment and produces less distress to the patients by avoiding repetitive injections. The study population consisted of 13 children with congenital nephrotic syndrome of the Finnish type (CNF). Peritoneal dialysis (CCPD) was started at the time of nephrectomy. Subcutaneous r-HuEPO-treatment was begun when blood Hgb value had fallen < 70 g/I. The mean age was 2.1 years (range 1.0 -6.1 y) and the mean weight 10.7 kg (range 7.9 -19.6 kg). The initial r-HuEPOdose was 20 IU/kg x3/wk and was increased by 10 IU/kg/2-4 wk up to 50 IU/kg according to the .response in Hgb. Of the 13 children 8 achieved a Hgb level of 100 g/I in a mean time of 22 wk (range 12-36 wk) where~s 5 did not in 16 wk (range 8-32 wk). In 2 patients the treatment was interrupted because of renal transplantation. The mean r-HuEPO-dose during the study was 39 IU/kg (range 27-47 IU/kg). The individual increment in erythrocyte mass varied between -4.0 and 2.2 ml/kg/mo. A poor association was found between the mean r-HuEPO-dosa and the erythrocyte mass increment (r=0.56, p= 0.0456).

On the other hand, a significant association was found between the serum albumin concentration and the increase of erythrocyte mass (r=0.767, p=0.0022). Further, a negative association was found between serum urea nitrogen and serum albumin (r= -0.809, p=O.0004) and between serum urea nitrogen and the ability to mobilze iron from the stores, as estimated by the decrease in serum ferritin concentration (r= -0.664, p=0.0153). We conclude that children with CNF on CCPD have protein malnutrition after nefrectomy and this limits their ability to respond to r-HuEPO-treatment, in addition, the severity of uremia, reflected by high serum urea nitrogen concentrations, also reduces the utilization of storage iron for hemoglobin production. RhEPO is established as effective treatment for the anaemia of ESRF but experience of its use in young children managed conservatively or by peritoneal dialysis (CAPD) is limited. 13 children age 0.1 -7.9 yrs, 5 pre-dialysis, 2 post-transplant (estimated GFR 4 -12 mls/min/1.73m 2) and 6 on CAPD were treated with s/c RhEPO in an initial dose of 50 -100 u/kg/wk as a single or divided dose for a mean (range) of 11 (4 -23) mths.

Mean Fib pre-treatment was 6.5 (5 -7.7) g/all and after 3 mths was 8.8 (7.3 -10.9 ) g/ldl. A single weekly maintenance dose of 168 (75 -250) in the conservatively managed group and 141 (15 -300) u/kg/wk in the CAPD group maintained the Hb at 9.3 (8.8 -10.4 ) and 9.9 (9.2 -10,6) respectively. In 6 children (3 predialysis, 3 CAPD) on RhEPO for at least 12 months the pretreatment Ht SDS was -2.7 (-3.9 to -1.8) and post treatment -2.0 (-2.9 to 0) p=0.1. Transient thrombocytosis occurred in 4 children, 9 required iron supplements and most experienced pain with injections. Hyperka/aemia and hypertension were not observed. There was subjective improvement in exercise tolerance and appetite in 11 children. In the pre-dialysis group, 1 remains on conservative treatment, 4 have been transplanted with only 1 requiring prio r dialysis for one month.

Carefully monitored treatment with RhEPO is well tolerated, improves the quality of life and may promote linear growth and postpone progression t 9 dialysis in young children with ESRF. Decreased bone 'mineralization has been observed in adults with idiopathic hyperealeiuria (1%I). The aim of this study was to assess bone mineral content (BMC) in children with lI-I (group 1); data have been compared with those of appropriate age and sex-matched controls (group 2). Group 1: twenty children (9 girls, 11 boys), aged 4 to 15 (mean -+ SD = 9.2 --. 3.4) years, time of follow-up r_anged from 0.9 to 7 years; four of these (20%) had calcium urolithiasis.

Group 2: twenty subjects (9 girls, 11 boys) aged 4.1 to 14.9 (8.2-+3.2) years without therapy or pathology interfering with calcium metabolism. Serum calcium (Ca), phosphorus (P), alkaline phosphatase, parathyroid hormone (PTH), calciuria and phosphataria were determined in the two groups.

We have examined BMC with forearm photon absorpfiometry; BMC was corrected also with bone width (BMC/BW). The paired Student's t-test was used to compare the mean, the correlation coefficients were determined by linear regression analysis, p< 0.05 was considered significant. Urinary calcium excretion in group 1 (5.5-+1.4 mg/Kg/day was significantly greater than in group 2 (1.7+0.8 mg/Kg/day p<0.801; no statistical differences were found for the other parameters between IH children and controls. The mean of BMC in group 1 (0.411__-0.17g/cm) did not differ from the mean in group 2 (0.373-0.17g/era) with p>0.1; the same result we found for BMC/BW. BMC correlated significantly with age both in 1H children (r=0.71, p,<0.001). In hypercaleinric children we observed a weak but significant negative correlation between BMC and UCa (r=0.41 p<0.05); BMC did not correlate with serum PTH.

These data suggest that there isn't a reduced bone mineralization in children with 1H. Recent literature has advocated aggressive medical management of XLH in children with 1,25 dihydroxyvitamin D (D) and phosphate (P) to maximize statural growth and minimize skeletal deformities. Attention has focused on hypercalcemia as the major complication of treatment. Hypercalciuria and nephrocalcinosis (NC) have not received adequate attention. In particular three questions arise: I) does treatment with D and P cause NC, or can it be an intrinsic part of XLH 2) does hypercalciuria (UCa/UCreat ~ .20) correlate with NC 3) is there renal morbidity associated with NC. Renal morbidity is defined as at least one of the following: renal colic, gross unexplained hematuria, renal insufficiency of any degree or passage of gravel or a kidney stone. 10 adults and 4 children with XLH and no history of any form of D or P treatment (Group I) and i0 adults and 8 children with a history of treatment with any form of vitamin D or P (II) had renal ultrasound read by a single pediatric radiologist, blinded to treatment status. RESULTS: No Group I patients had NC; 5 adults and 5 children had NC in Group II, .2 of whom developed it while actively treated. Hypercalciuric episodes were noted in 2/3 adults and 4/5 children in Group II. 4/5 adults and all 5 children in Group II with NC received D plus P. A single isolated episode of hypercalciuria was also noted in 2/3 children in Group II without NC. No patients in Group II experienced symptoms of renal morbidity by history or serum creatinine levels. CONCLUSIONS: i) Data suggests NC is a complication of the treatment; 2) Hypercalciuria may play a role in the development of NC; 3) No renal morbidity was noted in Group II patients; 4) The potential role of P therapy in the pathogenesis of NC remains to be determined. Two well-growing, asymptomatic brothers are described with hypophosphatanmlc hyperphesphaturia, hypercalcinria, tubular proteinuria, slight osteopoenia and medullary nephroealcinosis. In the In:st months of life both presented with hemoglobinuria and proteinuria. A renal biopsy performed at age 3.5 in case 1 was normal. At follow-up (14 years Case 1, 5 years Case 2) we determined the presence of hyperphosphatufia, progressively decreasing sP concentrations, hypercalciaria, microglobinuria, elevated sALP (90% bone fraction), a decreasing GFR and urinary concentration ability, and progression of osteopoenia (by mineralometry) and nephrocalcinosls (by US). sCa, PTH, s and ur Na, K, Mg, glucose & amino acids remained always normal. Extensive metabolic evaluation in both brothers excluded the known causes of uephrocalcinesis, intestinal malabsorption & hepatic diseases, & demonstrated phosphate leak, an increase of 1,25 (OH)2 D3 to suprapbysiolog!cal levels concurrent with progressively decreasing sP concentrations, augmented intestinal absorption of P and absorptive hypercalcinria. Phosphate supplementation as the sole therapy normalized sP and t,25 (OH)2 D3 concentrations, ar calcium excretion & bone mineral content. The rate of GFR decline and nephroealcinosls appeared to lessen. The only biochemical abnormality detected in the parents, the sister and 5 relatives in three generations was microglobinurla in the mother. This familial syndrome is biochemlcally similar to hereditary hypophosphataemic hypercalciuric rickets, but it differs because of the absence of rickets, and the presence of nephrocaleinesis and tubular proteinuria. CMA is a widely accepted cause for rickets or for osteopenia, but the relationship between CMA and bone disease as well as the mechanism(s) involved remain controversial.

A series of 11 children with primary renal tubular acidosis was evaluated before starting alkali therapy, for active plasma vitamin D metabolites levels (25(OH)D and 1,25(OH)2D), for iPTH using a 53-84 antibody, and for bone alterations using X-films. Age ranged from 15 days to 13 years. All had normal plasma calcium (Ca) and phosphorus (P) with elevated Ca ++ (1.38_+ 0.01 raM) levels.

Seven had normal hormonal plasma values (iPTH < 40 pg/ml ; 25(OH)D 9 to 14 ng/ml ; 1,25(OH)2D 26 to 60 pg/ml). Two (aged 3 and 13 years) had osteopenia and five, aged 0.5-11 months, had normal bones. Four chidren had evidence of vitamin D deficiency (25(OH)D < 5 ng/ml ; 1,25(OH)2D -< 15 pg/ml ; slightly elevated iPTH : 62-72 pg/ml) with signs of rickets.

An experimental study compared rats rendered acidotic by NH4C1 (1.4 %) in the drinking water (A rats, n = 15) and non acidotic pair-fed rats (NA rats, n = 15). PTH was measured with 1-34 antibody.In acidotic rats, histomorphometry of tibia diaphysis showed reduction in bone formation rate (double tetracycline labelling), and in osteoid seam thickness with enhanced endosteal bone resorption (surface not covered by labelling).There was no modification of plasma PTH and 25(OH)D and a slight not significant decrement of 1,25(OH)2D (p>0.10). Clinical and experimental studies showed that CMA induces bone osteopenia but does not directly cause rickets or osteomalacia.The bone alterations did not depend upon vitamin D metabolites or PTH modification.When observed in children, rickets appeared to result from associated vitamin D deficiency and not from CMA per se. In the early stages of childhood chronic renal failure (CRF) renal osteodystrophy and stunted growth are a therapeutical challenge! Most frequent causes of childhood CRF are apart from nephritic diseases malformations of the urinary tract such'as obstructive uropathy, renal hypoplasia/dysplasia and reflux nephropathy. Renal osteodystrophy may already develop at a 50% reduction of renal function. As part of the uraemic syndrome secondary hyperparathyroidism (sHPTH) and osteodystrophy are rather frequent at a glomerular filtration rate (GFR) of 25% of normal. Consequences in childhood are rather serious, because the epiphyses are still open and growth mainly affects bone mineralisation and remodeling, which are at a much higher turn-over-rate than in adults. Bony les~ons are osteitis fibrosa and osteosclerosis due to sHPTH as well as osteomalacia by reduced bony mineralisation. Clinical manifestations are stunted growth, skeletal deformity, myopathy, bone pain, impairment of gait, metaphyseal fractures and slippage of epiphyses. An exemplary report of the rare case of a 12-years old boy with CRF due to reflux nephropathy and classical clinical and laboratory features of renal osteodystrophy shall be given. Since the disease is a complex, multifactorial disturbance due to changes in the metabolism of vitamin D3, phosphate and Parathyroid hormone (PTH)~ treatment has to cover a wide range. Therapeutic goals are the normalisation of serum calcium, phosphate, alkaline phosphatase and PTH, the correction of metabolic acidosis as well as the prevention or cure of the skeletal changes. Ireatment includes dietary regimens (phosphate restriction), calcium carbonate (correction of hypoca!caemia, metabolic acidosis and hyperphosphataemia), calcium gluconate {prevention of hypocalcaemia) and oral substitution of vitamin D3 resp. 1,25(OH)2-vit-D3. The effectiveness of this schedule on the skeletal changes ~l~be~de~ons~ated. A successful renal transplantation is supposed to improve bone metabolic disturbances caused by chronic renal insufficiency. The objective of the study was to evaluate bone mineral status in children before and after renal transplantation (Tx). A longitudinal survey of bone mineral density (BMD) was performed in 22 children (11 girls, 11 boys) who received Tx at age 1.5 to 15.5 years. A triple immunosuppressive therapy including prednisone, azathioprine and cyciosporine was used after Tx. BMD of the lumbar spine was measured by dual energy X-ray abcorptiometry using Hologic QDR systems in all children within one year preceding Tx (TO), 6 months after Tx in 17 patients (T6) and 12 months after "Ix in 12 patients (T12). Renal function was stable in both groups at the time of repeated examination : mean _+ SD serum creatinine level = 72. 5 in chronic renal failure parathyroid glands show an abnormal responsiveness to hypocalcemic stimuli such as high serum phosphorus (P) levels. 5 males (7-16 yrs), withERI (Clcr 36-57 ml/min/1.73 sqm) secondary to tubulo-interstitial disease, with normal clinical, radiological and biochemical findings of bone metabolism and who had never received Vitamin D, were given an infusion of P (20 mg/Kg) in 30' Calcemia (Ca),P and PTH-NH2 were measured before and at 30 and 180 minutes after the end of the infusion The same test was repeated after 3 months therapy with oral calcitrio} (CT) (5-10 ng/Kg). Results: Mean (-+SD); Delta PTH = (PTH basal-infusion)/(PTH ,basal+infusion)/2; ~ vs. basal; ~p<O.05 vs, pre-CT. During a follow up period of 7 years, we evaluated BMD of 32 hemodialysed and transplanted childran. Total and mean BMD of lumbar spine and BMD of femoral neck were measured by dual energy with gadolinium, in 19 boys and 13 girls (12 to 20 years old). All these patients but 4 underwent a renal transplantation during the study. In hemodialysis, hyperparathyroidism has been controlled with calciuim carbonate and vitamin D supplement. After transplantation treatment consisted of Azathioprine, steroids and cyclosporine. All transplanted patients had a well functioning kidney during the follow up.

Results: an increase of BMD is noted in all patients. The BMD increase has a more linear pattern than in normal subjects with however a significant increase during puberty period. Steroids used in our transplantation protocol have a marked negative effect on BMD during the first year of Tx. The increase of BMD goes on after the end of statural growth. Renal osteodystrophy(ROD) and growth was assessed in 20 children undergoing CAPD. Mean age at the onset of CAPD was 7 years and duration of CAPD was between 1 and 7 years with an average of 3 years and 3 months. Serum calcium and inorganic phosphorus levels were maintained within normal limits in these patients. Elevated alkaline phosphatase and C-PTH levels and abnormal radiological bone changes of ROD were observed in patients with severe ROD, but they ~ not correlate in patients with mild ROD. Fifteen patients showed the radiological bone changes of ROD with deterioration and improvement in some patients. In I0 children under 6 years of age 5 showed the radiological changes of rickets and 7 showed the changes of secondary hyperparathyroidisms(2nd-HPT). In i0 children over 7 years of age 3 showed the changes of rickets and 8 had the'changes of 2nd-HPT. Administration of vitamin D seems to be necessary to prevent ROD during CAPD treatment. The growth of older children was poor during CAPD, but catch up growth was observed in young children under the age of 6 years. The growth was affected by rickets in young children, but the presence of mild 2nd-HPT seems to have little influence on growth in older children. On examination, the boy was of short stature (-2 BD). Him arterial pressure was 140/80 mm My and renal function was normal. X-ray films sho~ed two ~seous cysts of the ulna and ultrasou~ scan a hypoplasia of the right kidney. On DTPA ~intigraphy, slomerular filtrati~ rates were 65 and 6 ml/mn for the left right kidneys respectively, computeri~-ed engiogrephy eho~ed sten~es of the left renal artery and the hepatic artery ; the right renal artery could not be vieualimed. The pla~-~a renin activity of the riBht renal vein was three times that Of the left one. To evaluate the role of renal prostanolds, plasma renin activity (PRA) and plasma vasopressin (VP) in the development and maintenance of AH in GN we've performed RIA of 2~-hour urinary prostaglandins (I~G), PRA and VP in 6 non-uremic and 8 non-dialysed uremic hypertensive children with chronic GN, 22 normotensive non-uremlc children with GN and nephrotlc syndrome and in I7 health~ children (controls). All of them were free fmam drug therapy and sodlum-restricted. All GN groups demonstrated lowered production of vasodepressory renal prostacycllne (by urinary 6-keto-lOGF-I@~ ) whleh decreased gradually from normotensive to non-uremic and uremic hypertensive Stoups-and correlated with creatinine clearance (r = 0.6I, p< 0.05). Renal I~E2 was deereagea only in uremic hypertensive patients. Plasma VP was normal in hypertensive groups and slightly elevated in normotensive GN. PRA was increased together with sodium retention in normotenslve nephrotlcs and hypertensive non-uremlc children which had highest levels, while in uremic hypertenalves PEA was normal. No correlations with the level of BP were found. So, in non-uremlc children with GN AE may be medl ated by high PRA and sodium retention. In uremic children AS is likely to be due to decreased renal vasodepressory prostaglandins synthesis. VP probably does not play any role in the development of AS. We have recently reported that glomerular ANG I1-R density in 4-5wk old pre-hypertensive (PHT) is X1.5 that of adult SHR. Recent evidence also suggests that ANG II-R subtypes may change during development. The purpose of this study was to characterize ANG II-R subtypes in isolated glomeruli from 4wk PHT and 12wk adult SHR and WKY. Ligand binding studies were performed with [1zsI]-ANG II in the presence of varying concentrations of the ANG II-R nonpeptide antagonists DUP 753 and PD '~o~F~~ 123319, which selectively bind to type 1 (ATI) and type 2 (AT2) ANG ][I'R ! iI~ ~i~. ~ ~ sub-types, respectively. In the PHT~ SHR, inhibition of [125I]-ANG II binding by DUP 753 (Figure) indicated a single population of receptors ,. (K1=210!-_10 nM). Minimal radioligand binding inhibition (15%) was achieved -'~*""'~"~' "~ with PD 123319, even at 104M. Similar inhibition curves were demonstrated for the adult SHR and WKY (I~=200!42 vs K~=200i-_49 nM). We conclude that AT] subtype is the predominant glomerular ANG I/-R in the PHT SHR and while glomendar ANG II-R density decreases with the onset of hypertension AT l remains the prevalent subtypes. AT 1 is also the principle subtype in the adult WKY. Compared to single blood pressure (BP) ABPM every 20 minutes gives a more representative impression of BP. ABPM was performed in 18 HD pts aged 8-20 years, treated 3x4 h/week (mean interdialytic weight gain 4%) and in 17 PD pts (no weight gain) aged 7-19 years using the Spacelab 90207 device. ABPM was used in the whole interdialytic intervall (44h) in HD and during 24h in PD. The data were compared with the average of 10 routine BP recordings taken at home in PD and before dialysis in HD. Hypertension was defined as systolic or diastolic BP>95: th percentile (95c) for height. Antihypertensive drugs were given in 7 HD and 15 PD. Blood samples were taken simultaneously with ABPM for determination of vasoactive hormones. Results: hypertension was noted by routine recordings in 8 pts of either group and by ABPM in 6 HD and 16 PD pts. Four HD pts with elevated predialysis routine BP were normotensive when assessed by ABPM. Routine BP was below the 95c in HD (-10 mmHg systolic and -3 mmHg diastolic) and near this limit (-4 systolic, +2 diastolic) in PD. ABPM daytime means were below the 95c in HD (-8 systolic, -3 diastolic) but, in contrast, above this limit in PD (+8 systolic and +13 systolic; p<0,01 between the 2 groups). The nocturnal drop of mean BP was normal in PD (11 mmHg) and reduced to 4 mmHg in HD. BP of the second day of ABPM was not significantly different to the first day in HD. Median plasma atrial natriuretic peptide was increased only in HD pts (53 fmol/I in HD vs 18 fmol/I in PD, p< 0,0001) whereas plasma renin activity and aldosterone were within normal range. In conclusion, ABPM detects that hypertension is more prevalent in PD than in HD patients, despite signs of volume overload in the latter group. Neurofibromatosis is an autosomal dominant disease of the nervous system .It affects 1:2500/1:3000 persons in the general population. Vessel alterations can be observed in neurofibromatosis and may be classified in three different types (Reubi):simple intimal,intimalaneurismal and perierterial-nodular. It is possible to identify features of more than one of the pure types in the same vascular lesion.We describe two children who presented with severe arterial hypertension,in whom the diagnosis of neurofibromatosis was reached only after careful histological analysis of the kidney.The first case had a sole lesion of the right renal artery ,a nephrectomy was performed, with good clinical results.The second case was found to have an almost universal involvement of small,medium and large diameter arteries,this patient presented with severe hypertension of difficult clinical management and died at 5 years of age,in chronic renal failure.ln conclusion,the vascular lesions of neurofibromstosis,if carefully identified in the renal tissue can be of value for the diagnosis of this disease. 

Arterial blood pressure (BP) was continuously monitored over 24 hours using a portable monitor (Spacelab Inc, Kaarst, Germany) in 33 normotenalve children (group 1) and In 5 patients with end-stage renal failure and 4 patients with moderately impaired renal function (serum creatinine 80-160 pmoU1) (group 2). The results were compared to the European BP centlles (de Man etal., J Hypertens 9: 109, 1991). The day's mean of BP was calculated as difference in standarddeviations (SD) to the mean of the reference group with corresponding body height. The decline of the BP at night was given as the percent of the day's mean. RAS is the most common correctable form of secondary hypertension in children and adults. A satisfactory non-invasive screening test for RAS detection has not been available. Duplex ultrasound scanning of renal arteries using the conventional anterior abdominal approach to diagnose RAS by identifying Doppler waveform abnormalities in the area of stenosis has been associated with an unacceptable rate of technical failure and has limited accuracy. We report the use of a recently developed duplex screening test for the diagnosis of haemodynamically significant RAS. This technique assesses Doppler signal characteristics in the distal renal artery at the kidney hilum to detect the presence of haemodynamically significant RAS proximally. With the patient in the decubitus position, the hilum of each kidney is insonated via the flank using a 3MHz B-mode mechanical sector transducer with a 5MHz pulsed Doppler. The renal artery is visualized as a pulsation in the renal hilum and the Doppler cursor positioned in the vessel with a wide (15ram) sample volume and a 0 degree angle. Sample Doppler signals are recorded on heat-sensitive paper. The time between commencement of the systolic upstroke and the initial systolic peak is measured (acceleration time AT). Haemodynamically significant stenosis is defined by an AT of greater than 100 msec. No sedation or other preparation is necessary. The average investigation takes 10 minutes per kidney. Initially 58 patients withoul significant hypertension but with available angiograms were screened; none had RAS by AT criteria but four had significant stenosis by the angiographie criteron of >50% luminal narrowing in the renal artery (three had bilateral stenosis). Ten patients (eight adults, two children) with severe hypertension uncontrolled by maximum doses of three or more drugs were screened; 7 (6 adults, 1 child) had unilateral significant RAS by AT and by angiographic criteria, 3 (2 adults, 1 child) had no RAS detected by either technique. Three patients (2 adults, 1 child) underwent corrective surgery with subsequent significant amelioration of hypertension and normalization of Doppler signal. These preliminary results suggest that this practical, atraumatic and accurate screening test would be of value in children with resistant hypertension. C 178 P-IVA.41

Akinori Nishi*. Gianni Celsi. Anita Aoeria Karolinska Institutet, Dept. of Pediatrics, Stockholm, Sweden.

Dahl salt-sensitive (DS) rats is one of the most commonly used animal model for studying genetic hypertension that develop hypertension when fed a high salt (HS) diet. Since kidneys of DS rats exhibit an impaired intrinsic natriuretic capacity, we examined the effect of HS diet on Na+,K+-ATPase mRNA content in the renal cortex of prehypertensive (24-day-old) DS and Dahl salt-resistant (DR) rats. The mRNA abundance of both Na+,K+-ATPase ~1 and 13 subunits .was similar in the renal cortex from DS and DR rats on normal salt (NS) diet. After 2 days on HS diet, the abundance of al and l~ mRNA was increased in DS (2.01_+0.60-fold vs. 2.18+0.63-fold, P<0.05 for both subunit) but not in DR rats. The effect of HS diet on Na +,K+-ATPase mRNA abundance was not a pressure effect, since mean arterial pressure was still the same in 25-day-old DS and DR rats on HS diet for 3 days. The abundance of (zl and I~ mRNA in denervated kidneys from DS rats was also increased to a similar extent in response to HS diet (1.97+0.18-fold vs. 1.75+0.20-fold). The content of c~1 and protein in cortical homogenate was the same in 25-day-old DS and DR rats on both NS diet and HS diet for 3 days. Na+,K § activity was determined in permeabilized proximal tubule segments and in renal cortical homogenate from 25-day-old DS and DR rats. In both proximal tubule and homogenate, Na+,K+-ATPase activity was similar in DS and DR rats on NS diet. Three days on HS diet resulted in a 2-fold increase in proximal tubule Na+,K+-ATPase activity in DS (P<0.05) but not in DR rats. The activity in cortical homogenate did not change during HS diet. In summary, HS diet induces an early increase in mRNA for both Na+,K+-ATPase subunits in prehypertensive DS rats, which is associated with an increase in Na § activity in intact proximal tubular cells. These effects may contributes to salt retention in DS rats on HS diet. During the last years, it has been stressed that there is an high incidence of infection in C.R.F. patients associated with high mortality. Some significance has been attributed to dialysis procedures, to steroid treatment and to the basic pathology etc., without dearly establishing the importance of each one of these factors. For this reason some immunologic parameters have been evaluated in 20 pediatric patients with different degrees of C.R.F. of non immunologic cause, eutrophic, that ~ did not receive steroid, immunosuppressive treatment or dialysis.

The study considered the determination of the phagocytic., killing~ adherence and metabolic capacity of the polymorphonuelears, C.3 quantification, T and B lymphocytes and immunoglobulius A, M and G, i6 metabofic stable patients with no evidence of infection.

The results indicate that the phagocytic, kill;rig, adherence and metabolic capacity of the polymorphonudears C quantification, T and B lymphoeytes and-the immunoglobulius M and3G are normal in all evaluated children. However, the C and immunoglobulin A levels are significantly low (p> 0.01 and ~< 0.05 respectively), but without reaching the observed values in immunedeficleneies. The adherence capacity tends to dec~eese according to the deterioration of the renal function reaching glgnificant differenees (p< 0.01) in the group of children with severe C.R.F.

We conclude that with the obtained results we cannot associate the high infection incidence in C.R.F. with the immunologic alterations. Major and more complete studies are needed in order to obtain valid conclusions, but the sum of the immunological deficiencies plus the original pathology and the various procedures and treatments could explain the morbidity/mortallty in these group of children. Occlusion of the renal artery after indwelling aortic umbilical catheterization is the main cause of neonatal hypertension (HT). Ultrasound examination and DMSA Tc 99 scan are non invasive procedures which may allow thrombo embolism diagnosis and renal function assessment.

We report tensiormal and renal one year follow up in 4 term new borns presenting with severe hypertension during the first week of life after intensive care involving arterial umbilical catheterization.

-HT induced acute heart failure in 3 cases, a regular rise of blood pressure being noticed in the previous days. Hemataria and proteinuria were present in all cases at diagnosis, renal ultmsonography was normal but renal arteries doppler examination revealed blood flow abolition in right artery in patient 1 and 2, the two others being considered as normal. The rates of native renine measured by immune radiometric assay in the first week were : 100 ng/l in patient 1, > 270 rig/1 in patients 2, 3,4. DMSA scan performed 60 days (case 1) and 33 days (cases 2,3,4) after birth showed in all cases an involvement of the right kidney : total absence of uptake in cases 1, 2 and a global hypofixation in cases 3, 4. I-IT was easily controlled with drugs and treatment could be discontinued at one year of age in all cases. DMSA scan control at 12 months in 3 cases showed partial recovering in patients 3 and 4 and persisting complete loss of uptake in case 1.

-These data show a good correlation between doppler ultmsenography and DMSA scan and tend to confirm that, better than clinical (I-IT course), radiologlcal or biological (native renine rates) features, these two investigations allow both diagnosis of artery occlusion and accurate renal impairment evaluation at the early stage of the vascular accident. That would give possibility to intend an emergency curative procedure in order toprevent renal loss particularly when blood flow abolition in renal artery is present. Although a protein restricted diet is frequently used in chronic renal failure it is as yet not proven whether it has a beneficial effect on renal function of children with chronic renal failure. We wanted to know if a protein restricted diet can slow down or even prevent progression of chronic renal failure and whether growth of these children is affected. 56 children with chronic renal failure (GFR 18-63 ml/min/1.73m 2) entered the study. Age 2-17 years, mean 9 years and 4 months. Diagnosis: glomerulopathy (9); reflux nephropathy, obstructive uropathy and/or dysplasia (36), miscellaneous (11). To minimize interobserver variations one single paediatrician and one dieti,tian visited the patients in the different centres throughout the course of the study. After an observation period of three months the children were randomly assigned to a protein restricted group (0.8-1.1 g protein/kg/day) or a control group. Results after a follow-up of three-years: 1. GFR does not differ significantly between the protein restricted and the control group. 2. Statural growth was equal in both groups. 3. Compliance with the protein restricted diet, as indicated by the prospective diet diaries and the serum urea / creatinine ratio, was good. Dutch Kidney Foundation, grant no. C 87.645 and the Nutricia Research Foundation no.S 155715 and is part of the European multicentre study, BMFT grant no. 07047420/FRG. The treatment of chronic renal diseases has developed in recent decades, However, with even such treatments as steroid and immunosuppressive drugs, chronic renal diseases often progress relentlessly to end-stage renal failure. Alternatively, to postpone the initiation of dialysis therapy, oral administration of adsorbent for the removal of uremic toxins in the gastrointestinal tract has been tried in chronic renal failure (CRF). The spherical carbonaceous adsorbent(AST-120) ha5 been used in various stages of CRF with good results. We used it in the management of 20 patients with CRF, aged 5 to 17 years old. Following a base line period, it was administered to patients undergoing conservative therapy at daily dose of 2.4 g per 40 kg body weight, 3 times a day for period of 1.8 to 80.3 months. Value of serum crsatinine (S-CRTN) at start of study was 4.2•176 (Mean• mg/dl. Clinical courses were followed by several biochemical parameters before and after administration of the oral adsorbent. The results were evaluated by reciprocal S-CRTN versus time plots and analysis of Wilcoxon test (W-test). Slope of reciprocal S-CRTN versus time plots, pre-and post-administration of the oral adsorbent were -1550.6• (I0 -s dl/mg-month) and -913.2• respectively in 20 patients. Seventeen out of 20 patients (85%) were revealed effective to oral adsorbent therapy and W-test was significant (p<0.01). Uremic symptoms such as anorexia, pruritus and anemia were improved after administration of oral adsorbent. Most of side effects were rather mild gastrointestinal symptoms. We concluded that oral adsorbent (AST-120) was effective 4~. patients ~ CRF in conservative therapy, and observed satisfactory outcome even in patients ~ early stage of CRF. A developmental delay and encephalolmtby have been described in children with chronic renal failure (CRF). If compared to normal% the cognitive and motor development is delayed in these patients, It is questionable whether an early start of renal replacement therapy may positively influence their development. Over a period of 3 years a prospective study was performed with regard to the cognitive and neurological development of young children (< 5 years of age) with CRF (ereatinine clearance < 25 mi/min/1.73m2). As a part of this study brainstem auditory evoked potentials (BAEP) and somatoseasory evoked potentials (SSEP) were measured every 6 mont~. The study population consisted of 23 children; in 18 of them CRF was present from birth. Sufficient data for analysis were available in 19 (BAEP) and 22 (SSEP) children, respectively. BAEP's showed a significant delay of peak I, indicating peripheral disturbances of conduction, possibly due to cochlear dysfunction. Brainstem conduction was normal. There were no differences between the children treated conservatively (N=9) and those treated with CAPD (N=10). SSEP's showed in the younger age group (<2.5 years) a delayed thalamo-cortieal conduction, possibly indicating a delayed myelinatiun in these young children, since this phenomenon was not observed in the older are group. There were no differences between the children treated conservatively (N=10) and those treated with CAPD (N=12). It is concluded that the results of this study of BAEP and SSEP do not support the view, that earlier start of renal replacement start might be beneficial for the cognitive and motor development of young children with CRF. Today, HD prescription has to take into account the recent technology advancements : conventional or highly permeable membranes, acetate or bicarbonate or buffer free (biofiltration BF) dialysate, ultrafiltration control, diffusive (HD) or convective (hemofiltration HF) or diffusive snd convective (hemodiafiltration, HDF) epuration, sodium in the dialysate (NED) and/or ultrsfiltration (UF) rate modelling, compartmental epuration against water (NeD modelling), or phosphate (bicarbonate modelling) cellular sequestration. Most of the children benefits from capillary membranes and controlled UF. Only a few patients need UF r~te and NeD modelling to improve weight loss tolerance over session. Despite a larger range of molecular weight compounds epuration (ie B2 microglobulin) and more cardiovascular stability (HF effect), HDF is only ocoasionnaly performed in children. Use of highly permeable membranes requires enhancement of dialysate purity (to limit retrofiltration adverse effects) and adjustment of dialysate composition (to limit buffer or calcium intoxication). Today, dialysis dosis prescription is based on the ratio urea cleared volume (KT) over urea volume of distribution (V). Single pool urea kinetic modelling allows direct calculation of KT/V (delivered dialysis dogie) and protein catabolic rate (PCR) and urea time average concentration (TAC-urea) determination (quality of nutrition in regard to quality of epuration). Because of the real but only relative inaccuracy of the single pool model, partial dialysate collection,or, two pool model,two hours post session urea level use (to avoid error of post dialysis urea rebound) are proposed. We have the chance to test since more than ten years these new dialysis modalities, specially HDF, then NaD and UF modelling and bicarbonate modelling (BF with free buffer dialysate neither acetate nor bicarbonate) and to prescribe dialysis dosis by KT/V, PCRn, TAC-urea monitoring. Vascular access is a serious problem for pediatric hemodialysls patients. Under certain conditions it is necessary to use arteriovenous shunting processes. In this report we present 18 months followup results on 14 pediatric patients with synthetic vascular grafts inserted between May to September 1990. PTFE ringed grafts of 6 nun I.D were placed in 14 patients (8 boys, fi girls with ages ranging from 8 to 15) between the superficial femoral artery and the saphanofcmoral junction. In 10 patients (7_1%) grafts were functioning without problems after 14-20 months (17 + 1.3 months).

Grafts were removed from three patients within the first three months after implantation. In the first case there was serious hemorrhage at the arterial anastomosis site in the first month. In the second case secondary infection was observed after perlcarditls, in the second month. In the third case there was hematoma infection at the site of puncture in the third month. In the first and third cases failure was due to hypoproteinemia because of nephrotie syndrome, the primary disease. In the second, infection was responsible for the removal. A fourth case with late removal at fifteen months was due to hemorrhage at anastomosis site.

Synthetic grafts offer great advantages for pediatric hcmodialysis patients, but there are also some serious risks. For patients with hypoprotcinemia and infection PTFE grafts carry risks. After graft implantation llfe threatening hemorrhages can occur both in the early and late phases. After hemodialysis pcrigrapht hematoma at the site of puncture could cause serious complications. The use of continuous hemofiltration (CH) in pediatrics has recently expanded. More widespread familiarity has led to its use in an increasing variety of clinical settings. To evaluate the efficacy of CH, we determined the short-term survival (as measured by subsequent discharge from the hospital) of 77 critically ill patients, aged 1 day to 19 years, treated on 78 occasions with either continuous arteriovenous (CAVIl) or venovenons (CVVH) hemofiltration, or arteriovenous (CAVH-D) or venovenous (CVVH-D) hernodiafiltration from 1/88 -11/91. Indications for therapy included uremia, metabolic and electrolyte imbalances, and voltime overload. Eight of 16 patients with ARF due to sepsis/hypotension or SLE survived, as did 7 of 8 due to HUS. Four of 9 patients with hypoplastic left heart syndrome, 5 of whom had Fontan procedures, survived. None of 3 with cardiac transplant, AV malformation, or aortic coarctation survived. One of 3 patients with ALL and none of 7 with bone marrow transplant survived. Two patients with complications due to Rh incompatibility or Thalassemia died. One child treated for tumor lysis syndrome survived. Overall survival for ARDS was 6 of 22 patients, most with multiple organ failure. One infant was successfully treated with CH for ARF while on ECMO. Three of 9 children treated for complications of liver transplantation survived, while a patient with intussusception died. Treatment of 5 patients with congenital metabolic disorders was highly successful. Two of 2 neonates and one older child treated for hyperammonemia survived, as well as 1 neonate with primary lactic acidosis. Despite the lack of a control population treated with peritoneal or hemodialysis, the overall survival rate of 41% (32 of 78 treatments) indicates that a significant percentage of patients requiring acute therapy for life-threatening fluid, electrolyte, and metabolic derangements can be effectively and safely managed with CH. In our experience, CH is an efficacious alternative to peritoneal or hemc~tialysis, and can be used safely in the acute management of a wide range of illnesses encountered in pediatrics. The onset of end-stage renal failure together with a]! the associated medical complications of uremia comes as a shock to the child and his family despite any or all the previous psychological preparation. The onset of ESRF and subsequent hemodialysis is the beginning of a new scope of a variety of potential medical complications as well as restrictions and deprivations imposed on the child. It also becomes apparent that life as the family knew it will never be the same again. Beyond the practical problems of food, the whole family must cope with the reality of a child ~uho is not normal and healthy. When the initial shock is over, it is the task of the doctor and the family to achieve some measure of normai life and reinforce the child's confidence in dealing with his school and play world. The most successful tools that medical workers could use to achieve adjustment and coping skills would seem to be to encourage open and frank communication, both within the family and between family and medical staff. The complex saga of the kidney patient is linked intimately with the saga of the healtheare team. The nature of hemodialysis brings together a new pseudofamily structure, possessiveness and overprotectiveness become critical components in the resolution of care. In recent years, patients undergoing dialysis due to chronic renal failure have remarkably increased in number. From early childhood, these patients have often suffered from renal diseases and have complained of many physical and psychosocial problems. We would like to report a study with regards to the onset of renal disease, initial laboratory findings, psyehosoeial problems in their sehooldays in 695 adult eases who were maintained on dialysis. The results obtained were as follows:l) In 695 patients, the original of renal failure was chronic glomerulonephritis (61.0%), diabetic nephropathy (17.0%), nephrotie syndrome (7.5%), chronic pyelonephritis (33%), renal tuberculosis (3.0%), lupus nephritis (1.4%) and Alport's syndrome (1.4%), respeetlvely.

2) Their initial diagnoses were determined in the 3rd (26.9%) 2rid 21.5%) and 4th (15.3%), decade respectively. 85 cases (12.3%) were diagnosed in their teens. The mean interval between the detection of renal disease and start of dialysis was 11.73 years.

3) The renal diseases were initially detected by urinary masssereaning at school in 22 cases out of 695. 4) 31 eases out of 85, had experienced long absences during their sehooldays and 38 patients had lost their jobs owing to their bad physical condition. These results indicate that dialysis patients with early onset of disease have more difficult problems in their lives than those with later onset. Complement deficiencies occur in the nephrotic syndrome due to urinary protein loss. It was decided to study the complement system in children treated with CAPD with protein loss into the peritoneal cavity. In 16 patients (mean age 7.0 years, standard deviation 4.2 years) classical and alternative complement activity and serum level~ of seven components (Clq, C4, C3, C3d, B, D and P) were measured 9 Values were compared to those of a sex-and age-matched control-group of 44 healthy children 9 Mean total classical complement activity (CH50) was 471 U/ml in the CAPD-group and 375 U/ml in the control-group (P < 0.025). For total alternative complement activity (AP50) there was no difference between the two groups. The mean Clq level was 14.6 mg % in CAPD patients, which was slightly elevated compared to controls (12.6 mg %; P < 0.025). C4 and especially C3d levels were markedly elevated. Mean C4 level was 41.9 mg % in CAPD patients and 26.9 in controls (P < 0.001). Mean C3d level was 20.4 ~g/ml in CAPD patients and 6.7 in controls (P < 0.001). C3 levels were not different between CAPD-and control-group. Of the measured components of the alternative pathway (B, D and P) there was a statistically significant difference between the groups for factors D and P. Mean factor D level was 103.9 U/ml in CAPD patients, whereas it was only 6.2 in controls (P < 0.001). Mean Properdin level was 21.1 /xg/ml in CAPD patients and 16.8 in controls (P < 0.01). It is concluded that there is no deficiency of complement in these patients. High levels of C3d and D can be explained as a consequence of reduction of elimination by the kidney. The increased levels of the other factors are presumably due to an increased synthesis. The stimulus for this is not yet known. Nigl~tly intermittent peritoneal dialysis (NIPD) is an automated form oF ;ntermittent peritoneal dialysis which has potential medical and psychosocia I advantaqes i n comparison w i th CAPD/CC PD, due to izhe Iack. of daytime excl~anges. Data on solute/water removal in chil@er~ on NIPD are nevertheless scarce, so that no clear indications for NIPD can yet be formulated in pediatric age. For this reason, 12 patients, mean age I 0 49 +5.81 years, mean body weight 23.73 .~ 10.92 kg, with a residual creatinine clearance 1.70 ~ 230 and urea clearance 154 ._ ;tcJS~ ml/min/I 73 sqm, on NIPD for 147 _+ 5.4 months, underwent cleaf~n<ze studies ovec 3 days Mean dialysis infusion volume was 460.08 _* 19630 ml/kg/day with 10.33 ~_ 1.22 h. dialysis time. Peritoneal and combined (.residual plus peritoneal) creatinine and urea clearances ar~ ultraf.i Itrate/glucose absorption ratio were assessed. Peritoneal cre~iNr~ and urea clearances were 6.36-+ 2.96 and 8.49 + 3.35 I./day/l.7~ ~qm respectively Combined creatinine and urea clearances averaged 6.12 ~_ 2.21 and 696 +_ 2.16 ml/min/1.73 sqm, resulting in serum creatinme and urea values or 7.78 _+ 1.90 and 115.58 +_ 29.93 mg/dl respectively Ultrafiltration rate.was 1694_* 16.34ml/g glucose absorbed NIPD orovided similar or improved solute and water clearances compared with those reported in chi Idren and adults on CAPD/CCPD, without inconvenient tong periods in b~d These data indicate that NIPD is a suitable treatment in pediatric end-stage renal disease. Hypogonadism and growth retardation are frequent findings in pediatric patients under continuous ambulatory peritoneal dialysis (CAPD). The aim of this study was to analyze whether or not the amount of hormones lost through dialysis plays a role in these alterations. Ten children ( 7 to 14 year old; 4 male, 6 female ) under CAPD were studied. Concentrations of I~H, TSH and testosterone were measured in serum and in dialysis solutions. S(mmtcmetry and sexual development (Tanner scale) were evaluated. Growth retardation was present in all patients, who were below percentile 3, however, hypogonadism was not observed. A positive correlation was found between sert~ hormonal concentrations and the excretion through dialysis solutions.The amount extracted in dialysis was estimated as being less than I% of the daily amount synthetized. Serum concentrations of the measured hormones were within the normal range for sex and age, except for LH (r=0.935,p < 0.001 ). Our findings showed that the loss of sexual hormones associated to CAPD was relatively small and is agreement with the lack of alterations on sexual maturity in the population studied~ In spite of these results, there was growth retardation, that suggest the role of other factor in the uremic children participating in this abnormality. It is suggested that tidal dialysis (TD) is more efficient than conventional automated cycling dialysis (CD) because the peritoneal space is stirred and never emptied. We devised a model to calculate ID and CD clearances and compared these predictions to measured values in children.

CalcLdated cl,~,~mces.

We measured the equilibration half-lives (Et 89 of potassium, urea, glucose and creatinine across the peritoneum over 30 minutes in 5 children aged 0.8 to 13.2 years. The individual Et 89 values were used to calculate the predicted clearance for each substance in each child for 3 different rid regimens, assuming simple first order kinetics, and assuming that stirring conferred no benefit. Similar predictions were made for CD clearances, assL~ning dialysis to be effective during the dwell and for half of the fill and drain phase.

agreed closely (P<0.001) with calculated values for TD (n=60) and CD (n=20) modes, suggesting our prediction model is correct.

At fluid throughputs of i ml/kg/min clearances for all substances are comparable with TD end CD. Using TD at double this fluid throughput, clearances of substances with short Et 89 (eg potassium, urea) can be increased by about 40%, but substances known to have longer Et 89 (eg creatinine, phosphate) are only marginally improved.

C~m=lusi~m. TD is no better than CD when standard volumes of dialysis fluid are used.

If plasma potassium or urea levels pose an acute clinical problem their clearances could be increased by 40% by using TD and doubling the fluid used. The use of TD for maintenance dialysis may be justified in specific instances, but would be very expensive. AFB, technique which does not replace bases in the dialgeate and infuse~ hicarhor~te solution in the postdilution fluid, might provide o biocompatible dialwis, using acrglonitrile-derived membranes, sterile dfal~is cor~entrate without trace of acetate. Aim of this study w~ to investioste the AFB blocampetibility and tolerance in 9 children selected for AFB treatment on the basis of intredialytic h!jpotenaive episodes and/or uncorrected acidosis. C3a a.d CSa, leucocytes, TNF, neopterin, IL2R, 82 microglobultn, er~rsoyte malonil dialdehgde (RBC-HDA) were seqoentially measured durtnQ unselected dialysis techniques (basal values), 1 month of hemediaflttration (HI)F~ a~ after 1,3 and 6 rno of AFB. L/~L test ws performed on the dialg~ete: Acid-ba~ balance as well as diel~ts tolerarce were recorded. C3a levels significantly decreased after 6 me of AFB YS HI)F (p~O:.03) when evaluated at 0 (p~O.05), 5 (p~O.02), 15 (p~O.Ot) and 30 rain (p(O.05). CSa levels shotted only alight modifications. Leucoc~e depreeslon.~ signficantlg lover on AFB vs HDF (1~0.01). RBC-MDA and neopterin/creatintno were unmodified, wh|le TNF yes not detectaMe.62m 'post dialytiC: vetoes significantly decreased on HDF (p<O.01 va be~61 values) and remained: low on /fiB. IL2I~ pcat-dial~tic values significantltj deere~ed after/fib (p<O:05). After 3 ma of AFB ve observed a significant decrease in intradtalgtic episod~ of hypotension (p<O.01). A progressive improvement in final HC03 was observed during AFB (p<O.03 at l meand p<O.01 at 6 me). AFB is a ~ofe alternative in children with insufficient dtal~is tolerance due to intrediel~c hypotensiva episode or uncorrected ecidesta, AFB techntqna proved even mare hiocompatible than HDF. The advent of various modifications of standard CAPD, such as CCPD, NPD and tidal PD, has created the need for objective individual evaluation of peritoneal solute transfer and efficacy of dialysis. A Peritoneal Equilibration Test (PET) has been introduced for adult PD patients (Twardowski 1987) . To standardize a PET for pediatric use, we performed equilibration studies in 20 CAPD/CCPD patients aged 1.9 to 19.8 years. 1000 lnl/m 2 body surface area of a 2.3 % glucose PD solution were instilled in the peritoneal cavity. Glucose, creatinine, urea, sodium, potassium and phosphate were measured in the dialysate 7 times during 4 hours (D), and in plasma (P) after 2 hours dwell time. At 4 hours, the mean (• SD) D/P ratio was 1.06 _+ 0.16 for urea, 0.79 -+ 0.14 for creatinine, 0.82 -+ 0.21 for potassium, 0.92 ---0.04 for sodium and 0.79 -+ 0.30 for phosphate. Mean D/D^ of glucose was 0.36 -+ 0.13. The 4-hour solute equilibration curves w~re analytically best approximated by logarithmic functions for urea (mean R2=0.983), creatinine (R2=0.973) and potassium (R2=0.979), by a linear function for phos-phate (R2=0.964), and by an exponential model for glucose (R z= 0.969). The linear or exponential regression coefficients were used to express the peritoneal solute transfer rates. Although the transfer rates of most solutes were correlated with each other, the individual variation of peritoneal permeability for different solutes was hish, Close associ-ations were observed between the glucose and creatzmne transfer rates (r = 0.91, p < 0.0001) and between ultrafiltration rate and glucose (r=-0.90, p<0.0005) and creatinine (r=-0.88, p<0.005). Peritoneal permea-bility for all solutes tended to be inversely correlated with body size (urea transfer rate vs. height: r=0.49, p<0.05). We conclude that the PET may supply useful reformation on peritoneal solute transfer characteristics in children on PD and facilitate individualized PD prescription. Using a dwell volume scaled according to body surface area, small solute transfer rates decrease and glucose resorption increases with incre~ing body size. The purpose of our study was to evaluate LV morphology and function in HD children and the underlying hemodynamic factors. We performed 27 Doppler-echocardiograms with simultaneaous study of the fistula flow in 17 HD patients (9 male/8 female) aged 2.7 -20.3 years with Hb values of 7 -12 (mean 9.3) g/l.; all except one were treated by erythropoietin. 11 underwent an ambulatory blood pressure monitoring (ABPM) over 45 hrs. Based on the predialysis blood pressure (PDBP), ten patients were normotensive (4 treated by antihypertensives) and 4 hypertensive without drugs; 3 showed elevated PDBP despite treatment. ABPM mean daytime values were similar to PDBP in 7 children and discordant in 4. Mean LV wall thickness was increased (8.7• mm/m 2 vs 6.2• in control subjects, p<0.002). LV mass, calculated according to Devereux et el, ranged from 60 to 229 g/m 2 and was increased above normal limits in 11/17 pts. Cardiac index (CI = aortic flow/body surface area) ranged from 2.0 to 7.2 I/minim2 being increased above 3.5 I/minim 2 in 7/14 pts. Fistula flow ranged'from 0.44 to 1.73 I/minim 2. Shortening fraction, reflecting LV systolic function, was decreased (< 0.28) in 2/17 pts. The maximal velocities of early (E) and atrial (A) mitral flow pics suggested a subnormal LV diastolic function (E/A<2) in 12/15 examinations performed at HR < 80/min. No correlation was found between LV mass and PDBP or ABPM whereas LV mass was correlated to CI (r=0.68, p<0.005);.CI in turn was directly correlated to fistula flow (r=0.65, p<0.05) and inversely to Hb (r=-0.7, p<0.02). In conclusion, LV mass is frequently increased in pediatric HD pts. and is related to an increase in CI rather than to elevated blood pressure. The systolic LV function is usually preserved whereas the diastolic LV function seems to be disturbed. Plasma and muscle free ~ were determined in ~ children who started CArD at an age ranging from 8 to 16 months. The dialysis schedule was 4 exchanges per day of 40-45 ml/k~. Muscle biopsies were performed after 2-23 months of CAPD wh~e surgery was required for hernia repair or catheter replacement. Samples were taken from rectus abdominis, after an overnight dwell with 1.36% glucose dialysis solution, and the childPen were fastin~ from 12-15 hours. Data were compared with muscle samples from a control group of IO children with normal renal fanetion who were undergoin E elective surgery. Muscle intracellular water wan calculated usin E the chloride method. Plasma levels of most of essential AA (leucine, valine, threonine, lysine) and of some non-essential AA (serine, glutamine, aspaz,a~ine) were significantly Deduned. Plasma l-3-methylhistidine, citrulline, glutamic acid concentrations and the glycine/serine ratio were significantly increaned. Muscle AApattern of CAPD children and controls was similar except for a Deduction of leucine levels and an increase of aspartie and glutamic acid concentrations in dialysed patients. In comparison with data observed in patients with chronic renal failure or durin E maintenance hemodialysis, CAPD children showed a better preserved muscle AA pattern. Such finding could be explained by a modification of AA metabolism probably related to the CAPD hyperinsulinism. The reduced plasma levels of AA during CAPD might be attributed both to the chronic AA losses with the effluent dialysis fluid and to a shift, probably insulin related, of the AA from the extra-to the intracellular compartment. The results were as follows: From these data , younger children showed more severe impairment of growth at the onset of CAPD and better improvement of their gro~th than older children. It seemed difficult for children with end stage renal failure to grow well, but it seemed possible to improve their growth to some degree. The Italian Registry of Pediatric CPD is a permanent national registry, which started its activity in 1986. Since then i19 pediatric patients (age < 15 years at the start of CPD) have been enrolled and at present 15 dialysis centres are taking part in the Registry. The age of patients at the start of CPD was 8.5 • 4.9 years, and 21 children were younger than 2 years. Only CAPD was utilized in 1986, while automated peritoneal dialysis (APD) accounted for 5~% and 65% of the treated patients in 1989 and 1990, respectively. In this report we focused our attention on patient hospitalization / rate, patient and technique survival, and reasons for terminating CPD.The evaluation of the hospitalization rate refers to the 1989-1990 period. During a total of 901.5 months of CPD, 2814 days of hospitalization were registered, with an incidence of ~.i days/month. The hospitalization rate of patients who started CPD during the 2-year observation period (5.3 days/month) was different from that of patients already on CPD (2.2 days/month). The survival of patients was 99% and 91.3% at 1 and ~ years, while the technique survival at the same times was 98% and 79.3%. Sixty-nine patients ended CPD treatment during the 5-year observation period: 49 received a renal transplant; 8 patients were switched to hemodialysis (excessive peritonitis 5 cases, uncontrolled hypertension 1 case, patient/family preference 2 cases); 7 patients died after an average of 39.5 months of CPD, due to cardiac complications (2 patients), sepsis (I), cerebral hemorrhage (i), bowel infarction (i), while 2 patients died suddenly at home of unknown cause. Three patients partially recovered renal function; and 2 were transferred to an adult centre. may llmit the progresslon os amylold deposltlon.The aim of the study was the es%Imatlon os results os CAPD treatment in E children aRed illrrs wlth amyloidosis due to juvenile r~leumatold arth~i-9 is. in each 0s them protelnuz'la and hlrpePtenslon were observed after 44 and P4mths 0s s%eroid therapy respectively.Renal biopsy showed:amyloid deposlts/AD/ in mesanglal matrix and thickness os capillary nasement membrane. In pt I the decrease os protelnurla and normal blood pl~essure were noted after i mmu-~osu~resslve .therapy ~'chlol".ambucll.cyclophospnamla/.'rne dlecon~Inuatlon os the ~reatment caused ins i~iclent'heui-ngr@ase os proteinu~la,the appearance o, renal cy and Its rapid progression.The pt tl-ea-~al-ltlall~ with ~ was later transs to c~ es the pPog~esslon os ~Inutrltion,elrcula-to~y dlstu~bances and necessity os frequent blood trans~uslons. A 14 year old female on HD since 7 years was admitted with persistent fever of 1 month duration.

Primary renal disease was congenital nephrotio syndrome. The only abnormal physical finding was hepatomegaly. Laboratory findings were : erythrocyte sedimentation rate 120, normal blood cell count, negative blood cultures. Viral serologic tests were negative. No tubercle bacilli were isolated from gastric lavage. Chest X-rays were normal. Abdominal ultrasonography and CT-scan showed enlarged lymph nodes around the hepatic and celiac vessels. Liver and lymph nodes biopsy revealed diffuse non caseating granulomas. Four-drug antituberculous regimen was given for 2 months. Nevertheless, the disease worsened with high fever, weight loss, increased hepato end splenomegaly. Abdominal lymph nodes became palpable. Tubercle bacilli research remained negative on gastric and bronehoalveolar lavage (BAL), and lymph node calture. BAL showed lymphocytosis (25 %), with helper/suppressor ratio of 8, 4 (N = 0,87 • 0,15). Angiotensin converting enzyme level was 504 UI/I (N = 60-135). Polarized light examination of another lymph node biopsy and of liver biopsy showed abnormal particles inside granulomas. X-rays microprobe analysis did not find silicone but demonstrated whewellite deposits also recognized by infrared spectroscopy. Corticotherapy (2 mg/kg/day) induced dramatic general improvement. Hepatosplenomegaly, lymph nodes and fever disappeared. In conclusion, the cllnical presentation of this patient was similar to that of HD patients with granulomatosis induced by silicone deposits. But, in the present case, the granulomas appear to have developped around oxalate deposits, which, to our knowledge, has not been reported previously. The inhibition of the biological activity of insulin -like growth factors in renal insufficiency is not understood. It has been said that the excess of Insuline-like growth factor Binding proteins (IGF BP) may explain this phenomenon (1). We have studied the IGF BP in seven haemodialysed children (aged 8-14 1/2 yrs), with severe growth retardation. The mean Height Standard Deviation Score (Ht SDS) i for chronological age was -3,4 (0 to -11). A standardized insulin or glucagon kerlon GH provocation test was carried out. Six children had a GH peak above 10 ng/ml. A normal night GH profil was ,observed in the seventh child. Plasma IGF I, determined by specificl RIA, was normal. Analysis of the IGF BP using western ligand blotting was carried out before and after haemodialysis. This method reveals five IGF BP with molecular weight of 24, 30, 34,39 and 42 Kda, When .separated by western blotting, the sera showed a ':significant increase of IGF BP1 (30 KDa protein) and IGF BP2 (34 K Da protein). IGF BP3 (39 and 42 K Da proteins) seemed to be' slightly reduced. The IGF BP profil was not modified by haemodialysis. These results confirm a modification of the IGF BP in renal insufficiency.The abnormalities are similar to some previous results (2) but differ from others (1) . Future studies will be necessary to elucidate the role of these proteins in modulating the actions of the Nutritional status, assessed by anthropometric and biochemical methods, and muscle water, protein and amino acid composition, were evaluated in ii TxC and in a control group of i0 children with normal renal function who were undergoing elective surgery. Samples of the rectus abdominis muscle were taken when surgery was performed in the control children and when the peritoneal catheter was removed in TxC. Height was reduced in the TxC compared to the controls but skinfold thickness, arm muscle circumference and serum proteins were normal.The muscle content of total, extra and intraeellular water, and of alkali-soluble proteins (ASP), DNA and the ASP-DNA ratio in TxC was not significantly different from that in the controls, although a high significant correlation (r= -0.864) between the prednisone dose and the ASP/DNA ratio in muscle it was found. Plasma leucine level was significantly decreased, whereas plasma citrulline, alanine + taurine levels and the glycine/serine ratio were increased. Muscle threonine, aspartic acid, taarine + alanine and glycine levels as well as the glycine/serine ratio were iareased in TxC. Our data show that three months after transplantation, during corticosteroid therapy and despite its influence on muscle protein content, nutritional status and muscle composition were well preserved At the same time it was possible to evidentiate a near normal muscle AA pattern and plasma AA abnormalities which can be related to the prednisone therapy. The early correction in TxC of plasma and muscle AA abnorma]ities observed in chronic renal failure can be considered a further confirmation of the fundamental role of uremia itself in their genesis. The aim of our study was to deteamine B in children under hemodialysis (ED) treatment. We measured B in g children (3 boys and 6 girls), 7-18 years old, average 12 years, before and after every ED within 6 weeks. 27 adults on HD were measured for comparison. B was measured using a tetrapolar method, almost insensitive to the electrode-skin impedance, in supine position with 2 Silver-Trace electrodes on right am and 2 on right leg in the same place. We used MTT-01 device (Medical Electronics) Czech made, using 50 k~z and 800 uA. The number of repeated measurements ranged from 6-18, average 13.5. Our results: l.There are very high individual differences in B and total body water expressed as % of body weight (TBW%) in individual patients using the same method of treatment, calculated from equation TBW% = [height(am) z* 67.6] / [B(oh~) * weight(kg)] 2.The reproducibility of individual measurements is very good, the standard error was in range 1.9-4% . 3.The TBW% in adult~ before ED was significantly higher compared to children and adolescents (p<~,02).

4.The increase of B during one ED session was significant only in children and adolescents with low residual diuresie which needded higher ultrafiltration. 5.Despite of satisfactory values of homeostasis and no clinical signs of body fluid retention, we demonstrate the significantly higher TBW% in patients dialyzed 9-10 hours weekly compared to children dialyzed 12-13 hours weekly (~O.O0001)

We conclude, that the method of measurement of biolmpedance is very simply, non-invasive, with a sufficient reproducibility of repeated measurements in individual patients. Our preliminary results indicate that it is suitable to use bio~edance as one of objective parameters for evaluation of 'dry weighV of patients. Further studies in this field are necessary to evaluate the role of this method in the examination-scheme of these patients. In 12 infants with creatinine clearances <25 ml/min/l.73m 2 , growth and nutrient intakes were assessed prospectively during the first 2 years of life.

Controlled feeding regimens after 3 months of age, including enteral feedings by nasogastric tube and/or gastrostomy, were necessary to maintain adequate energy intakes. Growth parameters included length (L), weight (W), length velocity (LV), weight velocity (krV) and body mass index (BMI=W/L z ) expressed in standard deviation scores (SDS) relative to the ,normal population for age and sex.

A regression analysis correlating change (d) in L-SDS with LV-SDS was used to depict catch-up growth and was termed the growth velocity index (GVI). Total energy intake/ were maintained near 100% of the recommended dietary allowance (RDA) while protein intakes averaged in excess of 140% RDA. The most significant loss in all growth parameters occurred during the first 6 months with iO of 12 patients showing growth loss to an average length of -1.9 SDS. The maximum decline in growth measurements occurred at 12 months: L-SDS=-2.2; W-SDS=-I.7; BMI=-3.7. While ponderal indices (W-SDS and dBMI) showed recovery during the second year, LV-SDS remained negative and length S~S stabilized near -2 SDS. LV-SDS did not correlate with either nutrient intakes or degree of renal insufficiency at any age. However, average LV-SDS did relate significantly and inversely to C-terminal parathyroid hormone (PTH) levels. Our observations suggest that the critical period of growth loss in uremic infants is during the first 6 months of life when nutrient intakes are poorly controlled and requirements may exceed RDA. Inadequately treated bone disease as evidenced by elevated PTH had a negative impact on linear growth predicting the need for closer monitoring of Vitamin D therapy in these infants. Failure to thrive associated with poor appetite and vomiting is common in infants and children with chronic renal failure (CRF). We report our experience of the introduction of enteral feeding in 10 children (8M, 2F), with renal dysplasia (4), posterior urethral valves (5) and interstitial nephritis (1), followed up for an average of 26.6 months (12 -36). Mean age (range) was 1.88 years (0.48 -4.89) and mean estimated GFR 9.3 ml/min/1.73 m2 (5.4 -14.3 ). The feed was given via a nasogastric (9) or gastrostomy tube (1) as an overnight continuous feed with or without supplementary daytime boluses.

Mean estimated GFR was 7.5 ml/min/1.73 m2 (2.7 -13.5) at the end of follow up. Mean (SD) change in weight SD score at 1 year was 1.58 (0.81) and at the end of the study was 2.13 (1.26). Mean (SD) change in height SD score at 1 year was 0.52 (0.5) and at the end of the study was 0.99 (0.73).

Mean % of total calorie intake provided initially by the feed was 81.4 (49 -100) and at the end of follow up was 71.4 (38 -95).

Total calorie intake as a mean % of the estimated average requirement for chronological age was 84 (47 -124) at the s{art and 101 (87 -122) at the end of the study. Protein intake as a mean % of the reference nutrient intake for height age was 123 (77 -199) at the start and 140 (66 -297) at the end. 5 children have been successfully transplanted and have stopped enteral feeds. 5 continue on enteral feeds but have some normal dietary intake. Early enteral feeding in children with CRF promotes weight gain and linear growth despite declining renal function and does not preclude the development of normal eating habits.

Growth defect remains a problem in chronic renal failure, particularly during infancy which is normally associated with high growth velocity. Data on growth in uremic infants remain scarce. The aim was to describe growth in infants with well controlled treatment and steady GFR and to compare periods with different growth velocity. Twelve infants aged 1-10 months, with GFR ranging from 6 to 40 ml/min/1.73 m 2 (mean: 18.7 + 2.8), were followed for at least one year. Ten were growth retarded (-4.0 to -0.5 SD) and two had a normal height for age. Protein diet was 100% RDA (2.0-2.2 g/kg/day) as human milk or 60% RDA (1.3 g/kg/day) plus essential amino-acids. Energy intake was 100% RDA; it was increased if growth was lagging and was reduced if obesity developed. Tube feeding was necessary in 7/12 infants. Mineral and vitamin supplements were added when required. During follow-up length for age improved in 4 infants (+0.5 to +1.5 SD), remained on the same SD in 5,~ and deteriorated in 3 (-1.5 to -1.0 SD). Weight for age increased in 7 (+0.5 to +3.8), remained on the same SD in 3, and decreased in 2 (-0.5 SD). At last evaluation, 4 children were between -2.0 and -3.0 SD, 3 between -2.0 and -1.0 SD, 4 between -1.0 and normal mean, and one was on +0.5 SD. Energy intake had been reduced to 70-80% RDA in 4 infants, increased in 3, and left near 100% RDA in 5. Mean resting energy expenditure in the fed state, measured in 7 infants by indirect calorimetry, was 60.2 • 1.8 kcal/kg/day. Mean nitrogen balance under human milk (n = 7) was +340 + 5.0 mg/kg/day. All infants had normal blood pressure, normal acido-basic and hydro-electrolytic status, normal plasma albumin and transferrin levels. All had low plasma phosphorus (P) with high total and ionized calcium levels, as usually found in breast-fed infants. Plasma intact PTH was normal in all but 3. Comparing infants with stable, improved or decreased height for age, we found no difference in all the parameters investigated, particularly GFR, protein diet and blood urea, energy intake and energy expenditure, weight for height SD and biological data including plasma P and PTH. In conclusion: in well managed children growth velocity is normal in the majority of cases, but catch-up growth remains rare and height SD loss still occurs. These differences are accounted for by none of the currently available measured parameters and remain unexplained. We studied night time 12-hour plasma GH and GH-BP profiles, GH response to clonidine and IGF-I in 15 prepubertal ~hildren (10M, 5F) with CRF (GFR <25 ml/min/l.73m ~) (8 hemo, 5 peritoneal dialysis) 8.1!I.0 yrs (m• height SDS -2.5• and 30 prepuhertal age and sex matched normal short children (NS) height -2.3• SDS. Spontaneous (area under the curve) and stimulated GH (mcg/L) were significantly higher in the CRF (96~45 and 32.7+9.2) than in the NS patients (36.5+6 and 21.5+7.1 ) respectively (p<0.O01). GH-BP (mean 12hr, % of normal adult plasma) was lower in the CRF than in the NS subjects (45_+6.5 vs 59.5~7.6 respectively p<0.01). IGF-I levels were similar in both groups. Height velocity (cm/yr) after GH therapy (Serono and Novo-Nordisk, 0.125 U/kg/day in CRF and 0.i U/kg/day in NS) increased from 4.0• to 7.1 and from 3.8~0.8 to 8.4+1.2 respectively (p NS). The increment in weight increment was significantly smaller in the CRF patients. GH therapy induced a smaller increment in GH-BP and IGF-I (nMol/L) in the CRF as compared to the NS group (18.1• and 4.7• vs 28.1• and 8.4+6.3 respectively p<0.01). Both GH-BP and IGF-I are dependent on nutritional status. A partial explanation to the difference between the groups is that both caloric intake and weight gain were beter in the NS than in the CRF patients. Growth retardation is a frequent sequelae of CRF in children, and the prognosis for normal adult height is poor. We assessed the efficacy and safety of human growth hormone (hGH) in the treatment of such children. Nine children with CRF (M6, F3) m+gD 10.2+3.9 ~ (3.7-16.3y) were treated with r-hGH (Saizen Serene), 4 H/m /d s.c. Four patients were on chronic dialysis 2 and the remaining 5 had GFR values from iO to 17 ml/min/l.73m . Patients were measured every 3 mos. and bone age (BA) was determined prior to therapy and at 6 mos. of treatment. After 6 mos. of r-hGH therapy, growth velocity (GV) increased by a meanof 2.6!2.7 em/y (95% C.I.: 0.6-4.7), p ~ 0.05. Dividing the patients into 2 groups according to whether they were on chronic dialysis, the mean increment in GV was 4.1+2.4 cm/y (95% C. The treatment of vesicoureteral reflux (VUR) is still a much debated question; particularly there is considerable controversy regarding the management of severe VUR in neonates (especially VUR bilateral grade 5/5, because of its likely development towards chronic renal failure (CRF)). In many instances a medical prophylactic treatment is adopted by those who rely on a spontaneous disappearance of VUR. Those who favour temporary diversion (cystostomy) try to avoid the infections that may occur during medical treatment and the possibility of complications due to early surgical treatment.

We have always been on the side of early or even neonatal reconstruction of the ureterovesical junction and have now reviewed our experience and the results of surgical treatment of VUR 5/5 bilateral.

In the last 20 years we operated 68 patients with 5/5 grade primary VUR: 41 were bilateral affected. Out of these-41 cases we selected 38 subjects who presented a sufficient follow-up period (average 5 years and i0 months) to evaluate the results of the surgical treatment and the evolution of the re nal function. 32 of the 38 cases were male (84%) and 6 female (16%). 16 patients (26%) had had a previous antenatal diagnosis of urinary tract dilatation and they underwent early surgical correction during the first month of life, before the appearance of urinary tract infection. In the other 28 cases (74%), aged between 15 days and 36 months, the reflux was identified following clinical symptoms, mainly acute pyelonephritis. All the 38 patients were submitted to bilateral ureteral reimplantation using Cohen or Leadbetter-Politano technique; 22 refluxing ureters were tapered with the Hendren's procedure. Complications arose in 4 cases: 2 stenosis and 2 refluxes, the latter disappeared spontaneously. The incidence of surgical complications did not increase in the neonatal group of patients.

During the preoperative period and the postoperative followup we followed the value of serum urea, creatinine, creatinine clearance, maximum urinary osmolarity and blood pressure.

15 of the 38 cases (39%) showed a deterioration of these parameters before surgery, however, during the follow-up, 7 patients developed CRF and 1 of them required renal transplantation. 8 patients improved after surgical repair and they are still showing normal renal function (NRF); only 1 case of this group become hypertensive. No patients have shown symptoms of acute pyelonephritis in the follow-up.

The retrospective study of our series permits to point out that:

-the patients with antenatal diagnosis, early treated, seems to have a better prognosis (i0/i0 cases NRF); -in 5 out of 9 symptomatic patients having preoperative pathological value of renal function tests, we observed normal renal parameters after the early surgical repair, with was performed during the first two months of life;

-surgery had not changed the condition of CRF of those subjects who had a delayed diagnosis and treatment (3-36 m) .

To summarize, we consider early or even neonatal surgical treatment of VUR bilateral grade 5/5 highly advisable for the following points:

-excellent surgical results wich strongly suggest that the choice of diversion is useless;

-recurrent infections, sepsis or pyelonephritis, during medical treatment with make the prognosis of renal function worse; -early and definitive removal of VUR with surgery wich may help in improving renal function. Despite the obvious appeal of treatin~g meflux by a brief endoscopic procedure, concern remains about the long term safety of substances currently employed, particularly with regard to migration to distance organs. Under general anesthesia, 5 dogs were injected endoscopically with small volumes of Teflon paste in the manner used to correct reflux in children. Teflon particles were recovered from the lungs and brain within one week of injection. Long term cerebral changes induded pedvascuiar exudates and patchy demyelinatioa. Morphometric studies of alternative substances ~ currently in use, e.g., collagen and silicon paste show that these also contain small particles and are therefore likely to pose the same hazard. Lower urinary tract obstruction in the fetus is associated with poor perinatal outcome. A!though animal studies have demonstrated that early urinary decompression prevents lung hypoplasia and renal dysplasia, vesico-amniotic shunting has yielded disappointing results. Careful selection of ,pregnancies for prenatal treatment is crucial. Once other abnormalities have been excluded, the degree of renal damage is the major determinant of outcome. However, the antenatal assessment of fetal renal function is not standardized. Oligohydramnios is a poor prognostic sign, but is related more to the degree of obstructio6 than to urine production. In detecting the presence of urinary tract abnormalities, antenatal ultrasound has been reported to achieve sensitivity and specificity as high as 88% and 99% respectively. Identification of the specific pathology is however inaccurate, in particular, with respect to the upper urinary tract, misdiagnoses between hydronephrotic and multicystic kidneys have been reported in up to 53% of cases. Although the characteristic ultrasound appearances are distinct, gross pelvi-calyceal dilatations and multicystic kidneys with a large dominant cyst are indeed difficult to differentiate even postnatally. Since up to 40-50% of newborns with hydronephrosis require surgery, whereas conservative management is increasingly adopted for multicystic dysplasia, more accurate methods of antenatal diagnosis would facilitate prenatal counselling and postnatal investigation.

In order to facilitate differential diagnosis and antenatal assessment of renal damage in fetuses with lower urinary tract obstruction, urine has been aspirated from bladder or kidneys in a number of fetuses with urinary tract abnormalities and in a control group of 26 fetuses with normal amniotic fluid volume and anatomy ranging from 16-33 weeks' gestation. In the control group, urinary sodium and phosphate decreased and creatinine increased with gestational age, suggesting increasing glomerular filtration rate and progressive maturation of tubular function. Urinary sodium and calcium were significantly higher in fetuses with renal dysplasia compared with those with lower urinary tract obstruction but normal renal histology or normal clinical outcome. The highest sensitivity in the diagnosis of renal dysplasia was achieved by urinary calcium (100%), while sodium yielded the best specificity (80%). In doubtful cases, serial urinary samples, but not the determination of bladder pressure, helped in identifying those fetuses which might benefit from intrauterine shunting. Urinary I]-2microglobulin and NAG appeared to decrease with gestation in fetuses with or without renal dysplasia. Multiple regression analysis showed that this change with gestation is independent of urinary sodium only for NAG, but not for 8-2microglobulin. In the assessment of upper urinary tract lesions, urinary concentrations of sodium, calcium and phosphate were sigrlificantly lower in hydronephrotic than in multycystic kidneys, whereas urea and creatinine levels were higher. Determination of urinary phosphate enabled differential diagnosis with no false positive or negative cases. Amongst hydronephrotic kidneys, no biochemical parameter accurately predicted postnatal function, although creatinine was increased in all non-functioning kidneys. The degree of impairment of renal function in hydronephrotic kidneys, as documented by the urinary concentration of sodium, correlated with gestational age. Since the duration of hydronephrosis has a negative effect on renal function, the current policy of expectant management with antenatally diagnosed hydronephrosis warrants review. Fetal obstruction of the urinary tract may have a variety of consequences, including perinatal death, renal failure in infancy, or survival withour sequelae. In 101 consecutive cases of prenatally diagnosed bilateral obstructive uropathy, 15 fetal urinary parameters were determined. In order to identify prenatal factors predictive of postnatal renal function in childhood, survivors were followed prospectively from prenatal life to at least one year postnatally. A significant positive correlation was found between fetal urinary 112 microglobulin and serum creatinine at the age of one year (r=0,78, p<0.OOO1). For the prenatal prediction of high postnatal serum creatinine, the fetal urinary level of I]2 microglobuline was both specific and sensitive, sodium was sensitive but lacked specificity, glucose, phosphorus, calcium, osmolarity, and total proteins were specific, but lacked sensitivity. Our results provide a new approach for prenatal management of congenital obstructive uropathies, by allowing prenatal identification of the fetuses at risk for survival with postnatal renal failure. These fetuses might benefit from in utero therapy, while no attemps at prenatal uro-amniotic shunting should be made when a sponteously good outcome ~s predicted by fetal urinalysis. To our knowledge, this study is the first successful attempt at prenatal prediction of postnatal function after one year of life. The dilatation leads to a flap valve mechanism and to a functional obstruction of the bladder outlet and finally to secondary dilatation of the upper urinary tract.

This obstruction may be transitory; relfux and megaureters found in utero or after birth could be considered as sequellae of this phenomenon. From July 1988 through December 1991 stenfless hypospadias repairs have been performed by one surgeon for distal hypospadias. A total of 106 boys, ages 6 months to 10 years (mean 11.5 months) underwent stenfless outpatient bypospadias repairs. There were 18 GAP procedures, 69 Thiarscb-Duplay (modified King/F'lrllt) repairs and 19 Mathieu urethroplasties. Meatal location was proximal glans (10), coronal (13), sub coronal (25), distal shaft (53), mid shaft 4 and proximal shaft (1) . Chordee was present in 12 boys. 10 boys presented fully circumcised with hypospadias. Neourethal closure was performed under the microscope using a continuous 7-zero polyglycolle acid suture double r, nning subeuticular technique to achieve water tightness. The lateral glan wings were then re approximated in the midline along with the mucosa eollas to complete the repair. Chordee was either corrected via skin release (6) or torso-lateral Nesbitt plication (6) . Bupivicaine penile nerve blocks or caudal analgesia were given in all cases.

Follow-up has ranged from 3 months to 3 years (mean 15 months). With the exception of two older boys, all children voided spontaneously postoperatively. These two boys required outpatient placement of 5-French feeding tubes for 48 hours of urinary drainage without sequelae. Dysurla was incunsequential in patients less than 18 months of age. Older boys were given urinary analgesics to effectively lessen any dysuria.

There were no cases of meatal stenosis and a total of 4 fistulee. Interestingly 3 of the fistulae came in boys who had been fully circumcised before hypospadias repair.

Overall parental acceptance and ease of child care was deemed excellent. Based on this experience, the author feels that stentless repairs are safe and effective w~th the added benefits of improved patient comfort and easy postoperative care. The onlay island flap (OIF) urethroplasty is a variant of the tubularized transverse preputial island flap (TPIF) and is applicable to children with midpenile or distal hypospadias without fibrous chordee in whom the urethral groove is moderately deep. The technique involves preservation of the urethral plate, development of glans wings, isolation of a transverse island flap using ventral preputial skin, and suturing the flap onto the urethral plate.

The island pedicle is splayed over the flap to provide a vascularized cover and reduce the likelihood of fistula and the glans wings are brought together over the neourethra. The bladder is drained with a 6F polyurethrane or silicone urethral stent for 5 to 8 days postoperatively and a transparent dressing is applied. The repair is done on an ambulatory basis.

In a series of 60 patients undergoing the OIF repair, 5 (8%) had a complication requiring a second procedure. Complications included fistula (3), wound infection causing a retrusive meatus (i) , and flap necrosis (I).

In contrast, the complication rate with the TPIF was 16%.

In conclusion, the OIF provides excellent cosmetic results with a complication rate similar to the flip-flap (Mathieu) repair, and is useful in children with midshaft hypospadias without chordee, if the meatus is too proximal for a Mathieu repair, and in those with distal penile hypospadias with deficient penile skin. We first reported our experience with the use of full thickness free grafts supported by a ventrally transposed pedicle flap in 1988. From February 1986 to April, 1992, 62 patients underwent this technique. In 44 patients the free graft was fashioned into a tube; in 18 as an on lay. The hypospadlas was designated as mid shaft in 28, proximal in nine, penoscrotal in 21 and perineal in 4. Follow-up ranged from 1 to 74 months.

There were 9 patients (14.5%) with minor complications that did not require re-opcration. These included a retrusive meatus (coronal) in 6 (9.7%) and small fistulae that dosed spontaneously in 3 (4.8%).

There were 12 patients (19%) with complications requiring re-operation, In 7 (11.3%), a single procedure was necessary to correct meatai stenosis, fistulae and strictures. In 5 patients (7.7%), two or more procedures were required to achieve a satisfactory result.

The most common complications were fistula (8.1%) and the combination of stricture with fistula (8.1%). l patient had a stricture (1.5%) and another had a ineatal stenosis (1.5%). Clinical febrile wound infection, leading to fistulization, occurred in 1 patient (1.5%).

The advantages of a separate pedicle skin flap overlying the free graft are many. Most importantly, its application is independent of the free graft allowing increased flexibility in creating the neourethral.

In addition, the subdermai pedicle of the flap may be fixed to cover the entire repair from proximal anastomosis to the glans, creating a vascular shield. This manoeuvre sets the stage for engraftment and covers free graft suture margins. Finally, cosmetic appearance has generally been excellent compared to our experience with other repairs.

There has been no previous large series focusing only on severe hypospadias. We believe that the results achieved using this technique are good and possibly better than those previously reported. Urethrocutaneous fistnia is the most common complication of hypospadias surgery with most authors reporting a fistula rate of 10-20%. During the lust few years we have employed techniques that can be applied to a majority of single stage hypospadius procedures that have allowed us to substantially reduce our rate of urethrocataneous fistula.

All repairs are performed with the aid of 4.5X optical magnification, fince forceps traction sutures and delicate skin hooks are used to mlnirniTe trauma to the genital skin. Whenever possible, a single Stage technique util~ng vascularized preputial skin is used to form the neourethra. The skin tube is closed in two layers with 7-0 polyglaeln sutures. The second layer is placed in a simple interrupted fashion through the subcutaneous tissue in such a manner as to cover the original suture line. In addition, whenever possible a third layer of de-epithelized skin is used to wrap the neurethra. We routinely use a Firlit-Kluge urethral stent placed into the bladder and leave it in place for one week. A double layer bit-occlusive dressing is applied cireunfferentiany to the penile shaft. Optimal management of children with gross vesicoureteric reflux (VUR) andrenal dysplasia (RD) remains unsettled. We reviewed 8 patients with gross VUR associated with RD, treated and followed up in our departments since their birth, with reference to their management (operative vs. non-operative) and outcome. All patients (6 boys, 2 girls) were initially seen between l and8weeks of age. Initial plasma creatinine levels ranged between 2.2-2.7 mg/dl, and all had gross (gradeV) bilateral VUR. 2patients presented with febrile urinary infection, 6 with failure to thrive and 2 following prenatal U/S diagnosis. BPwas normal in all of them. 4patients were managed with primary ureteric reimplantation and 4 conservatively with continuous chemoproph~(laxis for at least 5 years. Assessment of renal function (RF] at the end of a 5-year period showed no differences in plasma creatinine level between the surgical (mean: 2.6, range: 1.8-3.2 mg/dl) and non-surgical (mean: 2.8, range: 2.1-2.gmg/dl)group. Thefrequency of break through urinary infection was identical in both groups (total: 4 episodes/group or O.2/pt/year). At the end of follow up, 2/8 ureters in the surgical groupand 7/8 ureters in the nonsurgical group werestill refluxing (>grade Ill). These data indicate that anti-reflux surgery does not affect the longterm outcome of RF in neonates with gross VUR and RD. If urinary infection can be sufficiently suppressed with chemoprophylaxis, conservative management with appropriate nephrological monitoring can be the primary mode of treatment. This prospective study was designed to establish the natural history of primary VUR, according to sex and grade. The criterion for entering the study was VUR identified during the investigation that follows a urinary tract infection (UTI). At entry, VUR was diagnosed by micturating cystogram. During follow-up, direct radionuclide cystogram (DRC) was repeated yearly. Reflux nephropathy (RN) was diagnosed by DMSA scan at entry and during follow-up. Two hundred-two children (mean-age: 31.5 + 23.3 months; 43 males and 159 females) were enrolled in the study. There were 314 refluxing ureters. High-grade VUR occurred in 141 ureters and low-grade in 163 ureters. The diagnosis of VUR was made significantly earlier in boys than in girls, both in low and high grade VUR (p<0.001). At entry, RN was present, on DMSA scan, in 44% of the 314 refluxing kidneys. There was no significant difference among boys and girls in the prevalence of RN. The renal lesions were more severe in boys, independently of the grade of VUR (p<O.05) Breakthrough UTI was significantly more common in girls compared to boys, both in low and high grade VUR (p<0.05). Mean follow-up was 68.7 __+ 31.2 months. Child's age at the time of the first of two DRC without VUR was considered the age of spontaneous resolution of VUR. Using life-tables estimations and analyzing data stratified to patient's sex and grade of VUR, we found that although VUR lasted longer in boys compared to girls, this difference was not statistically significant. During follow-up, 7 children developed new scars, related to breakthrough UTI. There was no significant difference among boys and girls on development of new scars. To better understand the natural history of VUR, children must be stratified by sex and grade of VUR. Prenatal diagnosis offers a good opportunity to study the natural history of vesicoureteric reflux prior to infections (UT]) We diagnosed primary VUR witha rnicturating cystogram, within the first two weeks of life, in 22 infant. ~ (34 ref!uxing kidneys), w~e,l~ a prenatally recognized hydronephrosis. 18 were Males (29 refluxing kidneys) and 4 Were Females (5 refluxing kidneys). In all cases 99Tc-MAG3 scan was performed within the first month of life, and all the patients received antibiotic prophylaxis.1 I patients( 18 refluxing units -group I) underwent surgery and 11(16 refluxing units -group !l) were medically treated. This different treatment was not determined by selection, but rather by the referra} pattern. All patients were followed monthly with urinocoltures; rerla} function was tested twice a year. NoUTIsoccurredbefGre the first renal scan Control micturating cystography was performed 12-18 months after diagnosis Or surgery Arelative uptake < 35 % in the umlateral'VUR, or the presence of severe renal scarring and uptake reduction in bilateral VU~ was considered abnormal Results: oracle VUR n of units Abnormal scan

Irl 7 14,3% IV 15 60 % V 6 66,6 % 4/l I patients of group I and 3/1 I of group II presented at !eaa~. une UT] during the follow up. in group II three of these occurred immediately after surgery. Contro} micturating cystography showed resolution of the reflux in 13/15 of the operated kidneys and in 5/10 kidneys iq medical treatment. Conclusions This study shows that 1 ) prenatal diagnosis allows to recognize :hat congenital refiux prevails in males 2) scintigrafic abnormalities are usually attributes ~o UTI in postnatal diagnosed VUR. In this study we showed that trey are present atbirth prior to any UTI in many cases and they seem to by proportional to the VUR grade 3)spontaneous resolution is possible even in high grade reflux 4) the success of early surgery is high. From 1984 to 1990, 30 infants (45 ureters) 6 weeks to 6 months of age (mean: 4 months) underwent reimplantation surgery. Weights ranged from 4.9 to 9.5 kilograms (mean: 6.9 kg). Underlying abnormalities were primary vesicoureteral reflux (28 ureters), primary ureterovesical junction obstruction (ii ureters), ectopic ureterocele (3 ureters) and ectopic ureter (3 ureters) . Patients with reflux under~_nt surgery because of high grade reflux (Grade IV, V), or breakthrough infection. Infants with primary ureterovesical junction obstruction had obstructive DTPA lasix renograms.

Procedures performed were 43 Glenn-Anderson advancements, one Cohen cross trigonal advancement and one Politano-Leadbetter. Thirty ureters (67%) were tapered. Ureteral stents were used in all instances and average length of stay was 10.5 days. Two children developed transient ureteral obstruction following stent r~noval and one required temporary percutaneous nephrostc~5, drainage.

No permanent ureterovesical obstruction was seen in any patient. Initial follow-up evaluation at six months revealed no post-operative reflux in 38 ureters (84%), while seven had residual reflux. Two of these ureters resolved after cystoscopic lysis of an intravesical band and one additional ureter resolved with observation only. One infant required re-reimplantation to correct a vesicoureteral fistula and three r~maining ureters are currently being observed. These last four ureters were tapered.

In conclusion, ureteral reimplantation was successful in 41 of 45 ureters (91%). The outcome was successful in 26 of 30 ureters (87%) which were tapered and in all of the non-tapered ureters. While many infants with vesicoureteral reflux and primary megaureter can be observed, surgery may be required in some. Reimplantation, when necessary in this age group, can be performed with minimal complications and with a high degree of success. In the last 20 years we operated 68 patients with 5/5 grade primary VUR: 41 were bilateral affected. Out of these 41 cases, we selected 38 subjects who presented a sufficient follow-up period (average: 5 years and 10 months) to evaluate the results of the surgical treatment & the evolution of the renal fanetion. 31 of the 38 cases were male (84%) & 6 female (16%). 10 patients (26%) had a previous antenatal diagnosis of urinary tract dilation and they underwent early, surgical correction during the first month of life, before the appearance of urinary tract infection. In the other 28 cases (74%), aged between 15 days and 36 months, the reflux was identified following clinical symptoms, mainly acute pyelonephrltis. All the 38 patients were submitted to bilateral ureteral re-implantation using Cohen or Leadbetter-Pofitano technique; 22 reflmdng ureters were tapered with the Hendrens procedure. Complications arose in 4 cases: 2 stenosls & 2 refluxes, these later disappeared spontaneously. The incidence of surgical complications did not increase in the neonatal group of patients.

During the preoperative period & the postoperative follow-up, we followed the vlaue of serum urea, creatinine, creatinine clearance, maximum urinary osmolarity & blood pressure. 15 of the 38 cases (39%) showed a deterioration of these parameters before surgery, however, during the follow-up, 7 patients developed chronic renal failure (CRF) and 1 of them required rena~ transplantation. 8 patients improved after surgical repair and they are still showing normal renal function (NRF); only 1 ease of this group became hypertensive. The retrospective study of our series permits to point out that:

The patients with antenatal diagnosis, early treated, seems to have a better prognosis (10/10 cases NRF); -In 5 out of 9 symptomatic patients having preoperative pathological value of renal function tests, we observed normal renal parameters after the early surgical repair, which was performed during the first two months of llfe; -Surgery had not changed the condition of CRF of those subjects who had a delayed diagnosis and treatment (3-36 months Hydronephrosis involving the upper pole of a duplex collecting system secondary to ureterocele was detected in 15 infants, twelve were diagnosed prenatally and three at less than two months of age because of a febrile urinary tract infection. Eight children underwent transurethral incision (TUI) of the uretarocele as their primary therapy, six had a partial nephrouretereetomy of the ureterocele segment and one ureterocele disappeared without treatment. The mean follow up was 30 months. The children all had a renal ultrasound and a voiding cystourethrogram performed to doetmaent the anatomy, and either an excretory urogram or renal scintigraphy preoperatively to evaluate the presence of absence of function in the renal segment subtended by the ureteroeele. In those cases with a functioning upper pole moiety preoperatively, TUI ureterocele preserved or improved function in the hydronephrotic segment, but when no evidence of function was noted preoperatively, TUI did not result in the return of any function. The ureterocele segments treated by partial nephrourcterectomy did not demonstrate any evidence of function preoperatively & all demonstrated histologic evidence of severe dysplasin inconsistent with the potential return of renal function. Following TUI of the ureterocele, reflux into the ureteroccle segment was documented in only one third of cases & thus far has not required surgical intervent/on. Reflux did not develop in any patient undergoing partial nephre -ctomy. We conclude that all neonates with duplex collecting systems & a ureterocele should have a conical renal scan to evaluate function in the upper pole segment subtended by the ureterocele. TUI uretero -cele is the preferred treatment option when this renal segment has evidence of renal function. Partial nephroureterectomy is indicated when there is no function. The intzoductinn of the anteaalnl diagnosis has changed the mode and age of presentation also in the primary obstruclivr megaureter (POM). In newborns the malformation might seem to ~preseat a differem entity from thai of the symptoll~ir cases observed previously; in f~'t, ha tim last few yeas many symptom-free babies with POM have been submitted to comervative r,~n~,~ement Howev~, approach is still controversial, mainly because it is difficult to define Inecme guidelines for the Iremmant and follow-up of this anomaly: usl-g only the criterion of renal fimedon deterioration may be tm'dy. The S.I.U.P. therefore decided to perform a retrospective study-on the Italian Sta-geoas' approach to POM in the period 1985-1989. The aim of the study wa~ to analyze theeXpefiencetodsteaadtodmw apastanda~code of practice. We collected iafonnstion about 473 cases, for 19/of which an an~natnl diagnosis had been made. We had asked for details about the degrees of dilatation and obs~clian, re~al function, treatment, evolution and complicaliona. The initial merit reanlted conservative i. 44.7% of the cases and surgical in 55.3%, with a higher incidence of expectant management in the babies diagnosed antenalally. However dnt'ing fullow-up more patim~ were given surgical treatment, brmgMg the total to 73.2% of the whole series. Tim consm'v~ve aptrroada was finally mpplied ~a o-ly 26.8% of the cases. Of the pafiems operated 321 were given reconstructive surgery, 21 a diversion and 4 a n~ptm~omy ; 81.5% of the m'etms were rmnodelled. The most commonly used technique of reimpisnmlion was the Cohen procednte (82.7%), the Polltano-Leadbeuer was mcerved to 14.4%. Post-operative reflux ocentred m about 8% of the cases and stenosis in 1.6%. We then evaluated the diffmrences ill evolmion and f'mal trea~ent between the newbora patients, diagnosed anteaatally ( 86% symptom-flee), and the older ones (89" symptomatic), SmWisingly, although a higher proportion of the newborns were treated conservatively, the data from the two grot~s re~ dilation, renal ft~c~on and the treslment appfied would not appear to show an)' statistically significant differences (p>0,05). This would seem to cast a doubt upon the conception that antenstally detected megamnter is a different entity from that in diagnosed later. Four patients with Type III posterior urethral valves are discussed. Two infants presented at two months of age with failure to thrive and renal insufficiency, one as a newborn with Potter's facies and bronchopulmonary dysplasia and one as a premature newborn with oligohydra~mios. In all four cases a urethral catheter could not be passed into the bladder. In Case 1 a retrograde urethrogram allowed contrast to go beyond the valvular obstruction into the bladder and in the three subsequent cases suprapubic percutaneous cystograms were performed. All revealed large smooth-walled bladders and small "beak-like" posterior urethras. In case i, rm/itiple attempts to pass a urethral catheter failed and he was managed with icop-c~taneous ureterostomy. He later required transpubic urethroplasty for dense stricture, secondary to repeated urethral trauma. Two infants were managed with vesicostomy and later transurethral valve ablation. One child died of respiratory failure shortly after birth. Of the three survivors, one has undergone transplantation and two have renal insufficiency. Thirteen additional cases of Type III valves have been reported in the past, for a total of 17 cases. Age of presentation ranged from one day to six years with clinical histories ranging from azotemia in infancy to mild dysuria in older boys. In 5 cases difficulty to catheterize was noted. Ten died and 4 have known renal insufficiency. The unusual smooth bladder and narrow posterior urethra were described. In conclusion, Type III valves present within a spectrl~, however, the mjority have significant renal impai~t.

Diaphragmatic valvular obstruction may make catheterization impossible. Percutaneous cystography can confirm the diagnosis and allow for short term decompression and stabilization. The presence of s~ooth-walled bladders with narrow posterior urethras is unique to Type III valves, but not always present. Prognosis for survival and renal function appears poorer than in the more common Type I valve patient. Urolithiasis after augmentation cystoplasty (AC) is an infrequent complication, as recorded in the literature. We retrospectively studied 27 patients (ages 1-30 years) without prior ~tone(S) who underwent AC between 1981 and 1991. Patients were followed serially with renal and bladder ultrasounds. S developed in 21 patients (79%); 13/15 with meningomyelocele/neurogenic bladder, 6/9 with bladder exstrophy, and 2/3 with other bladder abnormalities. Median time to S formation was 18 months post AC (range i month-6 years). S were located in the upper tract in 4 patients, in the bladder in 16, and in both loci in I. S developed after AC with a range of gut segments; gastric 0/I, ileum 4/4, ileoeecum 5/6, cecum 0/2, ascending colon 0/i, sigmoid colon 11/13. Of the 14 S analyzed, 9 contained struvite, either alone, or in combination with oxalate, apatite, or urate. There was no significant correlation between gut segment used and development of S, interval to S formation, S composition or location. All patients had multiple urinary tract infections with urea splitting organisms. Malabsorption was documented in 4/21 patients with S and 1/6 S-free patients (p=NS). No patients received known S-potentiating medication. Thus, none of these risk factors could distinguish between S and S-free patients. Sufficient data on urinary excretion rates of calcium, oxalate, citrate, and magnesium were not available for retrospective analysis.

We conclude that patients undergoing AC are at high risk for urolithiasis and should have close sonographic and radiologic followup. Pre and postoperative 24 hour urine for stone risk profile, measurement of urinary pH, and postoperative evaluation of bladder emptying dynamics, possible sites of heterogeneous nucleation (suture material, bladder mucus production), and malabsorption should be carried out in these patients to analyze risk factors and'institute appropriate preventive measures. Uroflowmetry studies are not well developed, even normal parameters are not defined in children.

We have undertaken a study to define the normal uroflowmetric values in children.

The urof'lowmeter used in our study was the Load Cell type with weight transducer. The different parameters studied were the volume of urine voided, total flow time (sec) (TFT), time to peak flow rate (see) (TPFR), peek flow rate ml/see(PFR), and average flow rate ml/see(AFR).

In this study boys aged 5-12 years of age without any renal zneuropsychological problems were evaluated.

Mean values for different parameters were as follows. PFR was II,14.25,18:AFR was 6.25, 11.9, 13.8: TFT was 10, 7.25, 9.6 :TPFR was 3,2.55,2.3 respectively for body surface area MZ(BSA) of 0.61-0.70,0.71-0.80 and 0.81-0.90 for a voided volume of 100ml.

For voided volume of 101-200ml the Values were as follows. PFR 16. 6, 17.28, 18.83; AFR I].90, 13.44, 13.63; TFT 11, 12.55, 11.36; TPFR 3.26, 4.51, 5.26; 20 and 20.8?; AFR was 13.5, 18.2 and 13.90; TFT was 19.2, 16.4 and 23.15 TPFR was 3.?, 6.4 and 8.85 respectively for the above BSA.

Our study has concluded the Uroflowmetrie parameters increase with body surface area and the volume of urine voided.

Uroflowmetric parameters are not age dependent.

This study has defined the normal uroflometric parameters in children. This can be used as a baseline data for future studies. Uroflowmetric studies are simple and noninvasive. Recently there has been renewed enthnsiasm revolving around the use of stomach and other tissues for b/adder reconstruction. The primary indications for these tissues arc in those patients who have functioning kidneys but who have renal insufficiency where the metabolic problems might be obviated. To date we have used the stomach in bladder reconstruction in 4 patients. These include a patient with an exstrophy of the bladder, 1 patient with myelomenigocele, 1 patient with posterior urethral valves and a patient with an end stage bladder secondary to multiple operations for vesicouretaral reflux. Besides using the bladder, we have recently had experience with two patients where massively dilated ureters have been used for bladder rccoustrruction including one patient with end stage renal disease secondary to prune belly syndrome and a patient with renal insufficiency and posterior urethral valves. The bladder capacity in all six patients has increased dramatically & the compliance most importantly, has been improved on urodynamic studies. All patients with uretero-cystoplasty & two with gastrocystoplasty void spontaneously to completion whereas the final 2 do require clean intermittent catheterization. Upper tracts have remained stable as has renal function in all those pts with functioning renal tissue.

Reconstruction of the lower urinary tract demands much creativity and the fi'ustratious and complications are many, In appropriately selected patients, gastrocystroplasty & ureterocystoplasty are attractive alternatives that should be part of the pediatric urologist's armamentarium. In all the cases whole colonic irrigation was used to ~repare the bowel for surgery whithout the use of co[ostomy.

The results were satisfactory in all the cases and there sere no complications,

The anatomic bases of the surgical approach are analized as well as the technical details of the procedure and the advantages compared with other techniques, used for the same pcrpuse.

Urine enzyme excretion was examined ha 8 patients with CRF (M:F=5:3), age range 4.6-15.5 yrs and levels of serum creatinine (SCr), BUN and GFR of 3.7_+0.4 mg/dl, 54.4+4 mg/dl and 22.4+3.4 ml/min/1.73m2 respectively. Enzymuria was also measured In 13 children (M:F=7:6) who received renal transplants (10 LRD, 3 cadaveric), with an age range of 5.1-17.1 yrs and levels of SCr, BUN and GFR of 1.48+0.27 mg/dl, 25+3 mg/dl, and 66.9+10.1 ml/min/1.73m~ respectively. Urinary enzyme excretion was measured in healthy, agematched children as controls

EFFECT OF RECOMBINANT HUMAN GRowTH HORMONE (rhGH) ON CALCIUM REGULATION IN SHORT SLOWLY GROWING (SSG) CHILDREN

At first evaluation, age was 2-14 m, GFR 5 to 30 (mean: 19.5 + 4.2) ml/min/m z, and height for age ranged from -4.0 to -1.0 SD. None had evidence of rickets. All received 100% RDA for proteins (2.0-2.2 g/kg/day) and energy, with tube-feeding when necessary (i-e 6 infants). The dietary P (25-30 mg/kg/day), Ca (70-80 mg/kg/day) and vitamin D (9-10 IU/kg/day) were the same in all children. During follow-up, 4 children remained on the same SD, 2 lost height SD (-1.0 and -1.5) and 2 had catch-up growth (+1.0 SD). Plasma P ranged from 0.76 to 1.80 mmol/1 (mean: 1.43 + 0.10) with total Ca ranging from 2.16 to 3.01 mmol/1 (mean: 2.61 + 0.03) and ionized Ca (Ca ++) ranging from 1.13 to 1.61 mmol/1 (mean: 1.36 + 0.03). Plasma P was lower in infants with lowest GFR; TRP was low in all (mean: 69 + 8 %). The high plasma Ca and Ca ++ levels led to give small amounts of vitamin D (< 0.1 p.g/day 1-alfa) or to withdraw it. All children had normal (10-25 ng/ml) 1-84 PTH levels, except one who had both low GFR (7 ml/min/1.73 m e) and low 25 and 1,25 (OH)2 vitamin D levels (6 ng/mt and 14 pg/ml). Two further infants developed a rapid rise in PTH (533 and 783 pg/ml), when given P supplement. Two developed rickets with high alkaline phosphatases (around 1000 IU/ml): one had received Ca supplement resulting in dietary Ca/P ratio > 4, and one had low plasma t,25 (OH)2 vitamin D levels with low GFR. In conclusion: feeding human milk supply low amounts of P resulting in low P and high Ca values, which are also observed in normal breast-fed infants without adverse effects

43 GROWTH IN UREMIC INFANTS : A STILL UNSOLVED ENIGMA

Japanese Multicenter Study Group of r-rGH in Children with Renal Diseases), Department of Pediatric Nephrology, Tokyo Women's Medical College

The purpose of this study was to determine the effective-heSS of r-hGH on somatic growth in uremic children as well as after renal transplantation in Japan. R-hGH was given in a dose of 1.0IU/kg/ week everyday subcutaneously. The study included. 21 uremic children (18 children were treated with dialysis therapy and 3 were under conservative treatment) & 7 renal transplants. The mean chronological age of 21 uremic children was 9

Their growth velocity before r-hGH treatment was 0.5 mg/kg/day. They were followed up for as long as 1 year or more. After r-hGH therapy 73.5% of uremic children clearly showed growth acceleration and growth velocity was increased to 6,9 • 3.3 era/year. Likewise, growth stimulation was noted in 71.3% of transplanted children and growth velocity was improved (4.8 +--1.5 era/year). No side effects including renal function were noted. From our results

We ~ )reviously reported mortality was 42% in U-GH and 31 in U rats p = 0.52). GFR was lower (p < 0.05) in U-GH and U animals vs. S & S-GH while U vs. U-GH was not different. Kidney weight to body weight ratio was lower in U vs. all other groups (p < 0.05) and returned to "normal

Excessive supplementation can result in nephrocalcinosis. The aim of this study is to evaluate simple methods for monitoring mineral supplementation and to investigate the influence of phosphorus supplementation on urinary oxalate excretion. Methods: 68 investigations were performed in 25 premature infants aged 3 to 18 weeks with a median birth weight of 1020g and gestational age of 30 weeks. The dayly calcium excretion (CaEx) is a good measure for calcium supplementation. Fractional phosphorus excretion (FEp) reflects glomerular phosphorus load, which depends on phosphorus intake and osseous incorporation

In 24 premature infants the effect of different oral phosphorus loads on urinary oxalate excretion was investigated. Results: Uoa/Cre a correlated to CaEx with r=0.81 (19<0.001), Up/crea tO FEp with r = 0.83 (p < 0.001 ). The diagnostic values for the detection of mineral excess or depletion were

02 mMol/kg*day

UCa/C~, 0.1 rag/rag: 100% / 97% FE v <3%

8 mg/mg: 100% / 90% FE v >15 %; Uc,/cr~" 2.2 rag/rag

No changes in oxalate excretion ensued after increasing the oral phosphorus load from 16 mg/t00ml milk (median Uox/crea: 257 mMol/Mol) to 40 rag/100 ml (Uox/Cr~,: 266 mMol/Mol) thus indicating that hyperoxaluria seems not to be responsible for nephrocalcinosis in phophate supplemented infants

La Ti References I. Smith D: A de-epithelialized overlap, flap technique in the repair of hypospadias

Outpatient repair of urethral fistulae

Results of closure of urethrocutaneous fistulas in children

Belman AB: De-epithelialized skin flap coverage in hypospadias repair

Tubeless non reductive pyeloplasty in the first year of life Belloli G., Musi L. Department of Pediatric Surgery -Section of Urology -Regional Hospital

The effect of vitamin E on the glutsthion redox system, haemoglobin (Hb) oxidation and the changes of haematocrit (Htc) as well as Hb were studied in haemodialysed children (aged 15.2+2.8 years) with erythropoietin (rh EPO) therapy. Vitamin E wa~introduced 2 weeks following the start of rh EPO treatment in the dose of 15 mg/kg/day orally (EPO + vit.E). The results were compared with the values obtained earlier in the same patients when they were treated with rh EPO alone with the same dosage. Hb concentration was significantlyhigher 2 weeks after the introduction of vit.E compared with the initial level and it was observed on the 8th week only, when they were treated with rh EPO alone. EPO + vit.E resulted in a more rapid increase in the Htc too which was also significant on the 3rd week (one week after the start with vit.E), but it was significant on the 5th week with rh EPO alone. The mean level of oxidized glutathione (GSSG) increased from 10.9+5.1 nmol/g Hb (x_+Sg) to 26.7+5.7 nmol/g Hb 2 weeks after staTt of rh EPO which deoreased sTgnificantly fellowing one week of vit.E introduction 10.1+4.9 nmol/g Hb (p< O.OO1) and remained on this level followingTy. Reduced glutathion (GSH) level showed a smaller elevation (P,i 0.05), but it also decreased significantly one week after the introduction of vit.E (p< O.O1). Similar changes were observed in the percentage of carboxy Hb and met Hb (p<O.O1). GSH oxidation and Hb metabolism are severly affected by an oxidative stress in the early period of rh EPO therapy. Antioxidant treatment with vit.E moderating the oxidative stress may increase the effectivity of EPO treatment. P-IVA. 3

Chfldrens Hospital, Free University Berlin, D.100O Berlin 19, Germany 161 anaemic (mean hematocrit {Hct} = 19.5 Vol%) children with ESRD were treated with rhEPO (Boehrlnger Mannheim, Germany) for a mean 335 days (range: 6 -05-days) . In the majority of the children (n=142) of rhEPO was given intravenously (IN) at an initial dose of 40 -100 U/kg body weight Co.w.) thrice weekly (T/W). 19 small children (mean age = 5.1 year) treated with CAPD received rhEPo intraperitoneany (i.p.) at an initial dose of 100, U/kg b.w. T/W together with half of the usual dialysate, After 1 year of i.v. treatment the route of adm;n;~tratioe was switched to subcutaneous (s.c.) in 47 ESRD children (mostly once weekly). Thereafter the individual rhEPO maintenance dose (rhEPO-MD) was adjusted according to the ceurss of Her. 

RhEPO can be administered i.v., s,e. and i.p. RhEPO should primarily be ~dmin;stered i.p to CAPD children (T/W) together with 50% of the dialysate. In haemodialysed children rhEPO should be given s,c. (once weekly). The younger the children, the more rhEPO is required to keep the Het at a level of approximately 30 Vol.%. 142 anaemic (mean haen~Hd)=19.5 %?o1.%) children with ESRD were treated with rhEPO(Boehringer Mannheim) for in mean 335 days (range:6-g23 days). 7@% of the children were growth retarded. ~eir height was (2 standard devia~on score (SD,S-h). The younger 1he children the more disbncs the growth retardabon was. ]'he initial rhEPO dose adminislered intravenousJy (i.e.) was 40-100 U/kg body weight (b.w.) thrice weekly. If target ~ ~b30 Vo.% was reached, the rhEPO dose was adjusted individually to maintain the incceased Hal.1. Renal anaemia could be corrected in all children and the transfusion dependency -observed in 122 children before start of rhEPO therapy -was eliminated within the first 3 moeths of rhEPO therapy. 2. 58 dzildren who have been treated wflh rhEPO for,%300 days (median 448 days) showed no significant changes in the SD~S-h, also in respect to the age and the primaly diseases. 3. Major adverse event was development or aggravation of hypertension.At the end of come.~don period 23 patients out of originally 62 normotensive pabents became hypertensive, in 25 out of 8o primarily hypertensive pabents the antJhypertensive therapy had !o be started or intensified.Conclusions: 9 The renal anaemia in children w~h ESRD ca. be corrected with rhEPO. 9 Increase of Hct :Jk30Vol% does not have any effect on growth retardation. 9 Major adverse event is dev~|opmenl/aggravation of hypertension. The effects of rhGH therapy on calcium regulation in SSG children without growth hormone (GH) deficiency are unknown. We prospectively studied 12 prepubartal SSG children (9 boys and 3 girls) with normal 24 hour GH secretion profiles. Ages ware 4.9 to 12 years (mean 9.6). rhGH was administered on six days par week subcutaneously, mean dose of 0.55 U/kg/wk. The results (expressed as means _ SD) ware: Nine boys with severe chronic renal failure aged between 4.8 and 15.6 years at the onset of the study, who have previously been reported after one year's treatment, have hada further 12 months' therapy with recombinant human growth hormone (Genotropin, Kabi, 30 IU/m2/week). They have continued on a strict low protein, low phosphate diet supplemented with keto and amino forms of the essential amino actds and histidine and additional ener~. They have been divided into two groups -prepubertai (testlcular volume <8 ml at end of treatment, n=5) and pubertal (testicular volume >8 mi, n=4).Mean height velocity in both groups remained significantly greater in the second year of treatment compared with at the onset of the study two years previously, but growth proceeded at a lesser rate than in the first year. The rate of deterioration of renal function remained unchanged compared with the firstyear although five children entered the dialysis program during this second year as predicted. Bone age advanced 12 months during the second 12 month period. There appeared to be no ill effects.Recombinant human growth hormone appears to be safe and effective in treating children with chronic renal failure for two years, although the growth rate, while remaining improved, slows down in the second year of treatment. We sought to determine if the anabolic effect of treatment with growth hormone in chronic renal failure (CRF) may sufficiently reduce renal solute load to slow deterioration in gllomerular filtration rate (GFR). Seven children, aged 2 -1 years, with moderately severe CRF (GFR 10 -24 ml/min/1.73 m 2) were treated with daily subcutaneous human growth hormone, 1 U/kg/week for 12 months. As expected, mean growth velocity increased from 5.1 cm/year (range 1.4 -9.4) to 9.5 cm/year (range 6.3 -11.1) and height standard deviation scores improved from -3.2 below the mean (range -2.0 to -4.4) to -2.4 (range -1.2 to -4.0).In the 12 months before treatment with growth hormone, mean GFR fell from 19.3 ml/min/1.73 m 2 to 16.7 ml/min/1.73 m 2. In the next 12 months on growth hormone, mean GFR fell further to 13.5 ml/min/1.73 m 2. Therefore the rate of deterioration of GFR was unaffected during treatment with growth hormone. Plasma urea concentrations fell in most patients during the first month of growth hormone treatment from a mean of 20.0 mmol/1 pretreatment to 14.8 mmol/1 after one month (p = 0.006) but then slowly returned to pretreatment levels over the next 12 months.We concluded that GH treatment initially lowers blood urea concentrations in children with CRF, probably by stimulating anabolic incorporation of dietary nitrogen into body protein. Despite the reduction in renal solute load however, renal functional deterioration continued unchanged. Acromegaly, a state of excess GH has bean reported to be associated with hypertension possibly due to salt and water retention. We were therefore interested to find out if BP changes occur in the course of long-term treatment with GH in children with various causes for short stature. BP was measured in 175 children entering the GH treatment program at 8 week intervals using a mercury sphygmomanometer. Diastolic BP was recorded at Korotkoff 4 phase. Standard deviation scores (SDS) for BP were calculated from data of the Second Task Force on BP Control in Children 1987 (Pediatrics 1987;79: 1-25). Because these children were small for their chronological age (CA), BP SDS were calculated also for bone age (BA). Thus far, 85 children had completed more than 2.5 years of observation on GH treatment; range 2. Chronic renal failure (CRF) in the young is complicated by growth retardation, hyperpara--thyroidism and uremic osteodystrophy. Many children with CRF are now being treated with GH. GH has a direct mitogenic effect on osteoblasts in culture.We studied the effect of GH therapy on parameters affected by osteoblastic activity like serum alkaline phosphatase (AP), bone GLAprotein (BGP) and bone mass density (BMD, by duel photon absorption) in poorly growing children with and without CRF. Fifteen (4F/IIM) healthy children with short stature (SS) and ten (3F/7M) children on renal replacement therapy (RRT) (5 hemo,5 peritoneal dialysis) 4.5-12.4 years of age were treated with GH in a dose of 0.i-0.125 IU/Kg/Day daily (Bin-Technology General, Israel) for one year. IGF-I, BGP, and BMD of spine were determined before treatment and after one year. During 1 year of GH therapy the changes in the SS and RRT groups were 190% and 180% in height velocity (p<0.01), 12% and no change in bone mass density, 230 % and 190 % in IGF-I, 140% and 125% in AP, 45% and 40% in BGP in the respective groups. BGP was significantly higher in the RRT group. We conclude that GH treatment increases growth velocity, and IGF-I in both groups of patients. Increase in osteoblastic activity was greater in children without RRT. Center. Results are presented on the pediatric patients. They ( or their parents) were interviewed regarding eight variables-sex,treatment type,rellgion,education levels, fluency in Hebrew and other languages , income, self-assessment of compliance, and family support . They were asked to record a three consecutive day food intake (later computer analysed).Blood test results were monitored, including potassium, phosphorous, BUN( for HD) patients, total protein (CAPD) patients, and weight gain between dialyses ( for HD). Dietary parameters checked were potassium, phosphorus, protein ( gm/kg body weight) and fluid intake. Overall dietary compliance was assessed using a PKPF (phosphorus,potassium,protein and fluid) intake index for HD patients, and a PKP (phosphorus,potassium,protein) index for CAPD. These were correlated with blood test results. Most correlations were weak. The dietary PKPF/PKP index was checked against the variables. Significant differences were noted for treatment type, (HD patients showing better compliance), language fluency-( those with no knowledge of Hebrew showed significantly worse compliance) and meligionthe Jewish patients had better compliance than the non-Jewish, mainly Arab patients. There may also be a strong cultural factor. Results indicate the need to carry out further research and develop dietary teaching tools which incorporate awareness of language and cultural differences.

S-U 1.1

Urine formation starts around the 10th week of gestation. Fetal urine is the major constituent of amniotic fluid and its production increases progressively throughout gestation. It approaches 28 ml per min near term. The urine is hypotonic, with concentrations of sodium, chloride and glucose well below their plasma values. This indicates active solute reabsorption by the renal tubular cells. Fetal kidney or urine tract malformations may give rise to oligohydranmios and/or impaired solute reabsorption, as evidenced by increased fetal urine solute concentrations. Because the placenta functions as a hemodialyser perfectly adapted to the fetal needs, fetal growth and functional maturation do not appear to be governed by functional requirements. The fetal kidney participates, however, in the regulation of fetal arterial pressure and hormonal synthesis.Hormonal factors modulate the fetal circulation and renal hemodynamics. At low renal perfusion pressures, as present in the fetus, glomerular ultrafiltration, the rate of which is governed by the balance between afferent and efferent vascular tone, glomerular capillary permeability and area, and the plasma oncotic pressure, depends Closely on the efferent vasoconstriction maintained by angiotensin II. Other factors such as the renal sympathetic nervous system, the prostaglandins, the kallikrein-kinin system, and the atrial natriuretic peptide also seem to play key roles in modulating the development of renal hemodynamics.Clamping of the cord is the signal for a striking increase in renal function. GFR rises rapidly, its value doubling during the first two weeks of life. So do renal blood flow and solute reabsorptive capacity. Changes that seem to be responsible for the rapid maturation of renal function include a decrease in renal vascular resistance, an increase in systemic blood pressure and effective filtration pressure, and an increase in the glomerular permeability and filtering area. The hemodynamic changes occurring during maturation are also mediated by vasoactive substances such as the prostaglandins and angiotensin II.Overactivation of intrarenal vasoconstrictors, such as angiotensin II, thromboxane A2, leukotrienes and endothelin, may severely impair the renal perfusion during development.Such an overactivation may result from endogenous stresses (hypoxemia, hypovolemia, hypotension), or urinary obstruction.Interference with the synthesis of these agents may also have dramatic effects on the development of renal function. Clinical examples include the inhibition of PG synthesis by indomethacin, the inhibition of angiotensin II formation by converting enzyme inhibitors, and the stimulation of ctadrenergic receptors by drugs such as tolazoline. The role of more recently discovered vasoactive agents, such as the atrial natriuretic peptide, nitric oxide or endothelin, in protecting or impairing the function of the stressed immature kidney is the object of present investigations. 

Before the advent of antenatal ultrasound, congenital uropathias llke vesico ureteral were mainly discovered during evaluation of urinary tract infection.The increase of prenatal ultrasonograpby allows recognition of VUR in the asymptomatic neonate and offers the opportunity to study the natural history of tins ,common anomaly before urinary tract infection appears.Intra-renal reflux (IRR) is more frequently observed in neonates and infants than in other children. Sterile IRR is harmless but provides potential access for bacteria into the renal parenehyma. The combination of IRR and urinary infection leads to renal damage and scar formation which may be prevented by appropriate uatibacterial prophylaxis. A full investigation of the urinary tract is necesary if ultrasound performed at birth and at day 5 confirms hydronephrosis. Neonates are immediately given prophylactic antibacterial therapy. Mictudtion cystography is performed at the end of the first week when upper tract dilatation is found on pre and postnatal ultrasonography.Neonatal recognition of VUR shows a strong male preponderance similar to other types of congenital anomalies of the urinary tract; Even severe grade 4 VUR can disappear spontaneously in half of the eases and improve in a further quarter after two years. A longer follow-up would probably show that a majority of these VUR's are going to disappear since VUR observed at a later age is essentially a female pathology.Differential renal function assessment using 99m Te-DTPA is carried out in all infants at 1 month of age and repeated at 6 months and thereafter once a year. A progressive increase of the renal function related to normal renal maturation is complete after 2 years of life in most children. However, VUR is associated with a small & dyxplastie kidney in few eases. Kidney function is less than 20% as measured by 99m Te-DTPA and typical dysplastie lesions corresponding to embryological defects in relation with the ureteral bud mal-developmeot kidney theory of Stephans.Despite the conventional practice of administering low dose antibiotic prophyla)ds, the incidence of breakthrough urinary tract infectious has been Mgh in some series. In our experience, 15% of infants presented with a proven urinary infection (uptake defect on DSMA scan in the acute phase before 2 months of life in all cases.There is a close relation between the time of onset of the appropriate treatment and the development of renal lesions explaining in our series the rapid and good recovery on DSMA scan without deterioration of renal fanetion. Surgery has been reserved for neonates and infants with breakthrough infection: they are considered as being at high risk for kidney damage. This attitude does not imply that they would develop recurrent urinary infection and potential further renal lesions. Until this point is proven we adopt a cautious attitude meaning surgically correetlon of the VUR when appropriate antibacterial prophylaxis fails. The incidence of urethrccutaneous fistulae, the most common complication of hypospadias repair, can be reduced significantly by preventing crossing suture lines.

Virtually all modern hypospadias repairs involve the intersection of at least a portion of the urethroplasty and the skin closure. It is at this junction that fistulae occur most frequently.By interposing a layer of tissue between urethroplasty and skin these crossing suture lines can be prevented.Smith (1) introduced a two-stage hypospadias repair which utilized a de-epithelialized flap in a "double~breasted" style to cover a midline tubularized urethroplasty.Complications of this second stage were at a minimum.This same philosophy was then applied to the repair of urethrocutaneous fistulae (2, 3) and, finally, to single stage hypospadiaa repairs. (4) The de-epithelialized flap can be added to all types of hypospadias repair other than simple glanuloplasties when adequate skin exists.After forming the urethra the remainder of the hooded prepuce is split and the cutis is removed in strips from a portion of one of these flaps using a tenotomy scissors.That de-epithelialized tissue is brought over the neo-urethra and sutured to the deep penile fascia with 7-0 absorbable suture. Ideally this flap extends from the new meatus at the tip of the glans to the proximal anastomosis. In a review of 84 single stage hypospadias repairs of all varieties only 3 acquired urethrocutaneous fistulae. (4) The application of the de-epithelialized flap to hypospadias repair significantly reduces the complication rate.It can be applied to most forms of hypospadias and is recommended as a simple adjunct to hypospadiology.We want to present our experience with the tubeless pyel~ plasty in the first year of life. Material and methods. From January to December '90, 395 infants and children for a total of 425 hydronephrosis have been operated on in our Department. Primary nephrectomy was carried out in ii patients (2.6%). 135 patients for a total of 147 hydronephrosis were less than one year old. in these infants 4 primary nephrectomies, 2 HellstrSm procedures, 46 Anderson-Hynes reduetive pyeloplasty with ureteral stent and 95 tubeless pyeloplasty without reduction of the size of the pelvis were carried out. Rssults. In 3 of the ~6 hydronephrosis in which a reduotive pyeloplasty with ureteral stent was carried out, a postoperative urine leakage:occurred, in 2 cases requiring a reoperation. In this group we had 2 failures due to postoperative strictures at the anastomotic site. In the group of 95 tubeless pyeloplasties without pelvic reduction we carried out 3 reoperations due to excessive urine leakage. In this group we had ~ failures due to anastomotic strictures. Conclusion. In our.opinion and experience the tubeless, non reductive pyelopladty is a safe and effective method to treat hydronephrosis also in the first year of life. In addition the tubeless technique does reduce hospitalization significantly. At the same time it is our opinion [that the reduction of the size of the pelvis is rarely necessary. The diagnosis of renal obstruction in asymptomatic nowboras with hydronephrosis is difficult. The diuretic ranogram conventionally used to examine ehildran with hydroncphrosis was modified to meet the special needs of newborns by a consortium of members of the Society for Fetal Urology and Pediatric Nuclear Medicine Club (May 1989) . This modified renogram is called the "Well Tempered Renogram (~) (protocol to be shown). About 150 imfants fi-om five different medical centers in the USA have been studied by ~ to date. Herein, the results of the Chicago Chil~ dreus Memorial Hospital are presented.There were 33 asymptomatic infants with hydronephrosis tested. Of the various parameters checked on the WTR, the best criteria to diagnose obstruction combined checking the values of the diuretic clearance after lusix injection (t 89 and the grade of hydronephrusis o,I ultrasound. The best correlation with surgically proven renal obstruction was a t 89 above 6mln in a kidney which showed hydronephrosis Gr~3 (polvocalyceal dilation) on the post WTR ultrasound. There was no instance of clinical obstruction when the t 89 was <6mln. The diagnostic accuracy during the value of the WTR t~ and other data from rcnogrmm and scan is about 60%, while correlation of the t 89 and the grade of hydronephrosis shows 98% accuracy.It appears the dual assessment (tV~ and grade of hydroncphrosis) is the most accurate means to evaluate dilated kidneys of newborns for obstruction. All 3 casea with poor results were reoperated and after second operation turned to Good (1 cane) and Acceptable (2 canes)respectively. Bad results were followed by nephrectomy in 3 of 4 cases. In all of these cases renal functlon was very poor (I case 27%; and Three cases uo functioning kidney at urography). In cases with renal function less than 45% (xxx) function improved after surgery. IT is emphasixed that renal function doesn't decrease after surgery. The fusctiou can improve after early operation or reoperation. Surgery is useless in cases with MAG-3 function less than 10~t or huge Hidronephrosis at urography. A rear--re ru~view ~ms dane on 117 pat.ients with ganiecurinary (~J) tramm fz~m over 4000 a~migsimns tm the C~HC Traurra prcgram (AL~ 1984 -MAR 1990 . Banal injuries, tDe ~s~ ~ injury, occurred in 50 pat-louts(47%). B 1~-and uxet.hral injuries acc~ in 8 patients (7.5%).Ur~eeral or f~ale ur~al in3ur/es ~zre not seen. Major mmml injuries occurred in 28 of t.he ~.Gross h~a-.~ria was asses!need with ~reiy f~ ~(p-0.05) Fif~y-nlne xray tesr.s war~ chtainsd(mze~ being CT scans), The m~st cri~ic~ ~~ of injury was extravaaatlmn (7/10 fractured kidneys for urethral reconstruction, have demonstrated encoura ging results and have promoted our initial experience with 3 pediatric and 2 adult patients. All the repairs have been completed as l-stage'prooed~ res, 2 for severe previously unoperated forms and 3 for cripples. The full thickness mucosal graft can be harvested from the inner surface of the cheek or the upper/lower lip, used as a patch or tube, alone or combined either with bladder mucosa or with preputial skin when available.Complications included 1 major fistula (probably related to distal meatal stenosis), 2 minor fistulas but no urethral stricture or diverticulum in the initial follow-up. Both the cosmetic and functional final outcome were good, suggesting that buooal mueosa can be used for hypospadias reconstruction as an alternative to bladder mucosa, when local skin is not available. Over a five year period, 26 patients aged 6 months to 14 years have undergone total abdominal rcconfiguration and ancillary procedures such as transabdominal orchidopcxy and when necessary urinary tract reconstruction for prune bony syndrome. This tcchnlque has been vastly improved so that the umbilicus is now preserved. Using the "pants over vest" pllcation of the abdominal musculature (as descrlbcd by Ehrlich, and most recently by Monffort) with resec.tlon of the redundant cutaneous tissue has left a satisfactory cosmetic appearance in all cases. Initially sloughing of the umbilicus with secondary healing was a problem in three patients in whom preservation of the umbilicus was attempted. Since then, when the umbilicus was left undisturbed on the underlying subcutaneous bed rather than on a pedide there have been no subsequent complications. One patient did separate a slight dehiscence of his skin anastomosis only which healed promptly by secondary intention leaving him with a good cosmetic result. Prenatal enthusiasm and satisfaction with the ultimate result has been universal in this patient group. Likewise patient satisfaction in the older children has been dramatic and been associated with improved self-image.We advocate abdominal reconstruction in children currently at six months of age in concert with orehidopexy whleh we feel can at times be done without the Fowler-Stepheus technique at this early age. This stud.y was performed as a part of longer research activity on children's urinary tract smooth musculature. All the 80 patients involved in the investigations suffered from urinary tract malformations and therefore underwent surgery. Children's ages ranged between 1 week and 15 years. Samples were taken from different segments of urinary tracts only at surgery. Immediately after cessation of blood supply specimens were prepared carefully for electron microscopy. Characteristic patterns like smooth muscle cells' sizes, organelles, pinocytotic vesicles, close contacts, amount of intercellular matrix, collagen and collagen fibres were examined. Specimens of nine children undergone urine diversion were obtained and investigated electron microscopically twice, first at diversion and later at undiversion surgery. Temporary cystostomy were performed on three of them for voiding disorders and temporary terminal ureterocutaneostomy were done on six patients for vesieoureterorenal reflux or stenotic ureterovesical junction. At present marks of regeneration of impaired smooth muscle microarchitecture will be discussed. Increased interstitial collagen and collagen fibres desintegrated. Smooth muscle cells rebuilded close contacts by producing cytoplasma processes between each other. Cell organelles and pinocytotic vesicles can be seen as signs of renewed cell activity. Taking into consideration that smooth muscle layer is able to regenerate in some extent pediatric surgeons and urologists should try to spare kidney parenchyma as far as it is possible.