id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-269913-ubtd3vdq	Tesfaigzi, Yohannes	Exacerbations of chronic obstructive pulmonary disease and chronic mucus hypersecretion	2006-06-28		.txt	text/plain	6985	326	37	The reasons for the natural cause of exacerbations in subjects with COPD are not clear; however, there is evidence that environmental pollution, such as the levels of SO 2 and NO 2 in the environmental air, as well as allergens and infections can increase the incidence of symptoms in some patients with chronic bronchitis or emphysema [26] . It is, therefore, possible that as a result of this innate immune response to environmental pollutants, allergens, and infections, sudden secretion of mucus can be triggered from the increased numbers of mucus-producing cells to cause airway obstruction and the associated exacerbations. This study shows that after ambulatory treatment of acute exacerbations of chronic bronchitis, a patient with ischemic heart disease who visited the general practitioner three times in the last year for respiratory problems has a relapse probability of 32.4%, which is statistically significantly higher than the mean 21% probability of the general cohort.	./cache/cord-269913-ubtd3vdq.txt	./txt/cord-269913-ubtd3vdq.txt