[Levels of melatonin in serum of patients with retinitis pigmentosa].

Purpose: To elucidate melatonin secretion through the pineal gland in patients with night blindness.

Material And Methods: Blood samples for melatonin RIA assay were taken from 14 patients at 8 o'clock a.m.

[Experimental studies of the effect of carbon monoxide on the retina of guinea pigs of different age].

Young and adult guinea pigs had been put in a chamber containing an 4-5 per cent addition of CO in the air. After 7 days of intoxication the authors performed a histopathological and histochemical examination of the retina. They discovered disturbances of the histological structure of the retina, a decrease of the content of nucleic acids and alkaline phosphatase and an increase of the acid phosphatase.

[Reaction of Langerhans cells of the corneal epithelium to topically applied lead].

Twenty guinea pigs were given a solution of lead acetate into the conjunctival sac. Ten animals from the control group received distilled water. In the contaminated group one observed conjunctival irritation and a paralimbal opacification of the cornea.