id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-295967-mmgb7cxo	To, L. T.	Transmissible gastroenteritis coronavirus: surface antigens induced by virulent and attenuated strains	1992-12-31		.txt	text/plain	3317	173	53	Summary Three strains of the transmissible gastroenteritis virus (TGEV) possessing different degrees of pathogenicity for piglets were examined for their capacity to express M and S glycoproteins on the infected cell surface using a microwell immunoperoxidase test. These two viral glycoproteins were easily detected on the plasma membrane of 0.1 % paraformaldehyde-fixed swine testis (ST) or pig kidney (RP.D) cells which were infected with high-passaged Purdue-115 and low-passaged D-52 strains and a high-passaged attenuated (188-SG) mutant of TGEV. Since the virulence of TGEV has been shown to decrease by serial passages in tissue culture, many authors have tried to differentiate the highpassaged (HP) attenuated strains from the lowpassaged (LP) virulent strain by in vitro markers, such as the level of the thermosensitivity of replication (Furuuchi et al., 1975; Hess and Bachman, 1976) , the resistance to digestive enzymes, low pH and temperature (Laude et al., 1981) , and by comparing viral replication and synthesis of structural antigens (Nguyen et al., 1987) .	./cache/cord-295967-mmgb7cxo.txt	./txt/cord-295967-mmgb7cxo.txt