id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-009907-4jfr98wl	Nelson, Randy J.	Minireview The influence of season, photoperiod, and pineal melatonin on immune function	2007-01-30		.txt	text/plain	9969	590	43	Short day lengths enhance several aspects of immune function in laboratory studies, and melatonin appears to mediate many of the enhanced immunological effects of photoperiod. Taken together, it appears that seasonal fluctuations in immune parameters, mediated by melatonin, could have profound effects on the etiology and progression of diseases in humans and nonhuman animals. Many other conditions perceived as stressful, such as reduced food availability, low ambient temperatures, overcrowding, lack of shelter, or increased predator pressure, can recur seasonally leading to seasonal fluctuations in immune function among individuals, and seasonal changes in population-wide disease and death rates [Lochmiller et al., 19941. Evidence will be presented that pineal melatonin plays a critical role, both directly and indirectly through its effects on other hormones, in mediating photoperiodic modulation of immune function. Because exposure to short day lengths suppresses circulating prolactin levels, this hormone is a possible candidate for mediating some of the reported seasonal changes in immune function.	./cache/cord-009907-4jfr98wl.txt	./txt/cord-009907-4jfr98wl.txt