[Analysis of DNA status in bone marrow cells of mice internally irradiated with 90Sr ]. / Otsenka sostoianiia DNK kletok kostnogo mozga myshei pri vnutrennem obluchenii ot 90Sr.

The response of bone marrow cells of CBA mice injected with 22.2, 222 and 592 kBq/animal to additional gamma-irradiation (3 Gy) for testing purposes was evaluated using SCG (Comet assay). A decrease in induction of DNA damage right after additional gamma-irradiation was determined. It correlated with bone marrow cell quantity and the tail length before additional gamma-irradiation. The results support the suggestion about the activation of DNA repair in bone marrow cells under exposure to 90Sr in vivo.

[Biological effects of acute external or internal irradiation of rats in the framework of nitrite intoxication]. / Biologicheskoe deistvie ostrogo vneshnego ili vnutrennego oblucheniia krys na fone nitritnoi intoksikatsii.

The material presented provides evidence that high nitrite doses have a various effect under the condition of external or internal radiation. Thus, nitrite protector properties were observed in male rats exposed to external radiation using the LD50/30 while following 90Sr exposure male rats of the same age showed a higher sensitivity to the radionuclide. The nitrite combined with optimum carcinogenic 90Sr dose had a potentiating effect on both life-span shortening and increase in osteosarcoma rate in the animals.

[Characteristics of the effect of irradiation at different dose rates on survival, death kinetics and response of critical systems of the C57Bl/6 mice]. / Osobennosti deistviia oblucheniia s razlichnoi moshchnost'iu dozy na vyzhivaemost', kinetiku gibeli i reaktsiiu kriticheskikh sistem u myshei C57Bl/6.

A comparison was made of the biological effect on mice of irradiation at different dose rates (70, 5.5 and 1.5 cGy/min) with equally effective, with respect to lethality, doses, or with physically equal doses within the range from 1/4 of LD50/30 to LD99-95/30. Equally effective, with respect to lethality, doses caused similar changes in the intestinal epithelium and in the haemopoietic system. The death rate kinetics was identical with doses of LD80-95/30 within the dose-rate range under study. The equally effective doses caused injuries, different in degrees, to critical systems, including CFUs.

[Changes in the resistance of mice to whole-body lethal irradiation after local irradiation of the abdominal area]. / Izmenenie rezistentnosti myshei k obshchemu letal'nomu oblucheniiu posle lokal'nogo oblucheniia oblasti zhivota.

The resistance of mice to whole-body irradiation with lethal doses, after preirradiation of part of the abdomen, was studied with a reference to radiation dose, the volume of local exposure, and the interval between exposures. The radioresistance was found to increase when the preirradiated zone corresponded to the spleen projection, the interval between exposures was 3-7 days, and the dose of local exposure, 2 Gy.