[Age-related radiosensitivity of the crystalline lens in chronic experimental internal irradiation with 137Cs at low doses]. / Vozrastnaia radiochuvstvitel'nost' khrustalika pri éksperimental'nom khronicheskom vnutrennem obluchenii 137Cs v malykh dozakh.

Internal whole-body irradiation of mice for 1 year with incorporated 137Cs at a dose of 0.5 eV was shown to make a significant cataractogenic effect on the lens. By annual rate this dose exceeded the existing maximum permissible dose only three times and was less than 10% of a cumulative dose for professionals having to do with ionizing radiation which they can accumulate at the maximum permissible dose level in annual irradiation for 50 years. The time of recorded lenticular opacity reduced and a degree of observed changes increased in the study groups as compared to the unirradiated control group indicating the involvement of a radiation factor in their development. More pronounced sensitivity of the mouse lens to chronic radiation exposure in the second half of the life than in the first half was noted.

[Dose-effect relationship based on frequency of occurrence of radiation cataracts]. / Zavisimost' doza-éffekt po otsenke chastoty vozniknoveniia luchevoi katarakty.

The paper is concerned with the results of experiments on random bred mice concerning dose-effect relationship estimated by radiation cataract developing 1 year after x-ray irradiation at doses of 0.05, 0.5, 4, 7 and 10 Gy. It was shown that the effect of ionizing radiation on the lens registered by its opacity, could be threshold-free and described with the equation of the straight line. The authors found it appropriate to introduce a concept of a permissible risk dose causing a certain degree of cataract. In their opinion, the existing maximum tolerance radiation dose based on the absence of cataract at doses less than 7.5 Gy, should be lowered not less than by one order.

[Inhibition of the growth of 7,12-dimethylbenz(a)anthracene- and N-nitrosomethylurea-induced mammary gland neoplasms by methionine in rats]. / Tormozhenie metioninom razvitiia raka molochnoi zhelezy, indutsirovannogo 7,12-dimetilbenz(a)antratsenom i N-nitrozometilmochevinoi u krys.

The diets supplemented with 0.5% methionine inhibited the development of mammary adenocarcinomas induced in female rats with 7,12-dimethylbenz(a)anthracene and N-nitrosomethylurea by 3.8 and 2.3 times, respectively. Methionine produced no effect on the incidence of other new-growths. It is suggested that the mechanism by which methionine exerts an antineoplastic effect on mammary carcinomas is a consequence of its hypolipidemic and neurotropic activity.