Nihon rinsho. Japanese journal of clinical medicine
-
Melatonin(N-acetyl-5-methoxytryptamine) is synthesized from tryptophan and is intensively secreted into the blood only in darkness (nighttime) by the pineal gland. Melatonin is not only the most reliable marker of internal circadian phase but also a potent sleep-promoting and circadian phase regulatory agent in humans. There is evidence that daytime administered melatonin is able to exhibit short-acting hypnagogic effect and phase-shifting of the circadian rhythms such that sleep timing and associated various physiological functions realign at a new desired phase. Under favor of these properties, melatonin and melatonin receptor agonists have been shown to be potent therapeutic agents for the treatment of circadian rhythm sleep disorders and some type of insomnia.
-
The Ministry of Health, Labour and Welfare and the Heatstroke STUDY 2008 & 2010 regarding the characteristics of laborers who suffered and died from heatstroke demonstrated the involvement of more laborers who worked in construction, from July to August and at around 3 p.m. Also, more laborers who worked at around 11 a.m. got heatstroke, and there were more laborers who died from it within 1 week from starting to work. The results showed that the heat environment and the time and period when laborers started to be exposed to a hot environment adversely effect the development of heatstroke and subsequent heatstroke-related death. It is important to estimate and take measures against a hot environment and to make time to be acclimated to a hot environment.