[Evaluation of the effect of dose rate and dose absorption on the long-term radiation consequences in rats chronically taking in 90Sr]. / Otsenka vliianiia moshchnosti dozy i pogloshchennoi dozy na otdalennye radiatsionnye posledstviia u krys pri khornicheskom postuplenii 90Sr.

The effects of exposure to 90Sr which was given with food with daily doses 18.5 kBq per animal for 1-12 months, 37 kBq per animal for 1-10 months, 74 kBq per animal for 1-8 months and 148 kBq per animal for 1-6 months on mortality patterns in unimbred white rats were investigated. Hazard models were used to evaluate dose rate and accumulated dose influence on radiation-related trends in mortality. The time-dependent risk of death from all causes and from osteosarcomas depended on the dose rate. The risk of death from causes other than osteosarcoma depended on the dose rate and the accumulated dose. To predict time-dependent risk of death it was better to use the least time to calculate the dose rate--1 day.

[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.

[Schematic model of genesis of osteosarcoma induced by Sr-90]. / Skhematicheskaia model' osteosarkomogeneza, indutsirovannogo 90Sr.

The development of radiation osteosarcoma genesis scheme induced by 90Sr was the subject of the present study. The production of cancer cells after exposure to a specific dose-rate of emitting 90Sr incorporated in the skeleton are typical for the initiation period. However not all the cells remain in the mutant DNA. In some of them DNA reparation occurs, other cells are killed in the process of the subsequent divisions, and only a few of them containing mutant DNA are preserved in the state of repression up to the end of life time. Disorders of homeostasis due to exhausted of physiological reserves - (natural or early aging) are manifested as a promoter. In that period the derepression of mutant DNA occurs and malignant growth of tumor starts.

[Effect of Sr-90 on the reproductive function of rats after chronic exposure]. / Vliianie 90 Sr na reproduktivnuiu funktsiiu krys pri khronicheskom ego postuplenii.

In experiments on white rats following long-term 90Sr exposure within a wide dose-range the effect of 90Sr on reproductive function of animals has been observed both over the entire reproductive period and in seven subsequent generations. It has been established that the ovule fertilization and the intrauterine fetus development did not differ from these values in control animals. However in some cases the loss of progeny was significant following the isolation of animals from parents. The physical development of rats in suckling period and sex proportion did not differ from the control progeny.

[Incidence of the development of 90Sr-induced osteosarcomas depending on the age of the animals]. / Chastota razvitiia osteosarkom, indutsirovannykh 90Sr, v zavisimosti ot vozrasta zhivotnykh.

In experiments with albino male rats, a study was made of the influence of age on the incidence of osteosarcomas induced by 90Sr. It was shown that the incidence of tumors decreases exponentially with age.

[The effect of pesticides on the development in rats of osteosarcomas induced by 90Sr]. / Vliianie pestitsidov na razvitie u krys osteosarkom, indutsirovannykh 90Sr.

In experiments with rats the authors have assessed the development of remote effects of radiation (90Sr) combined with chronic exposure to chlorophos and lindane within a wide range of doses. It has been shown that chronically administered chlorophos and lindane have no carcinogenic and cocarcinogenic effects.

[The effect of joint, radiation and chemical lesions in rats on their reproductive function]. / Vliianie sochetannogo, radiatsionnogo i khimicheskogo porazheniia krys na ikh funktsiiu razmnozheniia.

In experiments with rats exposed to the combined radiation and chemical effects it was shown that fertilization of an ovum and the development of fetus did not vary from these indices in the controls. Viability of sucking rat pups isolated from poison did not vary from the controls as well. Sensitivity of posterity to the toxic effect of chlorophos and lindane was found to increase.

[Changes in various indicators of cellular immunity in rats in chronic radio-chemical exposure]. / Izmenenie nekotorykh pokazatelei kletochnogo immuniteta u krys pri khronicheskom radiatsionno-khimicheskom porazhenii.

The experiments on rats exposed separately and in combination to radiation and chemical substances showed that the time of body pesticide intake (the total dose) was the leading factor affecting the phagocytosis indices. A daily pesticide dose had a credible impact on some indices. The combined effect was formed primarily due to chemical compounds. In general the effect could be regarded as less than additive though at some time it was additive and more than that.

[Biochemical changes of the liver in rats with a combined lesion from 89Sr and 131I]. / Biokhimicheskie izmeneniia v pecheni krys pri kombinirovannom ikh porazhenii 89Sr i 131I.

The results of the biochemical changes induced by 89Sr and 131I in a rat liver after their separate and combined administration within a wide range of doses are presented. Administered in a combination the radionuclides produced the additive effect when estimated by some indices, and more than additive, according to other tests.

[Combined lesion in rats from 89Sr and 131I in their repeated uptake into the body]. / Kombinirovannoe porazhenie krys 89Sr i 131I pri mnogokratnom ikh postuplenii v organizm.

The results are submitted concerning the biological effect of 89Sr and 131I delivered separately and in a combination within a wide dose range. 89Sr has proved to be the major contributor to the effect observed. The effect produced by the radionuclides delivered in a combination was lesser than additive.

[Changes in the content of carbohydrate-containing proteins in the liver of rats chronically exposed to pesticides combined with total gamma irradiation]. / Izmenenie soderzhaniia uglevodsoderzhashchikh belkov v pecheni krys pri khronicheskom ikh porazhenii pestitsidami v sochetanii s obshchim gamma-oblucheniem.

A study was made of the chronic effect of pesticides, within a wide range of doses, combined with whole-body gamma-irradiation, on the content of carbohydrate-containing proteins of rat liver. The extent to which disturbances in the carbohydrate-containing protein metabolism were manifest was shown to depend upon dose and time of action of the damaging factors. As determined by certain parameters, the combined effect of pesticides and gamma-radiation at the biochemical level was additive, and it was more than additive as estimated by a number of other tests.

[Effect of homologous immunoglobulin with normal anti-tissue antibodies on the development of strontium-90-induced osteosarcomas in rats]. / Vliianie gomologichnogo immunoglobulina s normal'nymi protivotkanevymi antitelami na razvitie u krys osteosarkom, indutsirovannykh strontsiem-90.

In experiments on Wistar rats it was shown that homologous immunoglobulin (a single dose of 25 mg/kg), with normal antitissue antibodies, subcutaneously injected in the following manner: a single injection 90 days or 6 months, or double injection 3 and 6 months after intraperitoneal administration of strontium 90 (11.1 kBq/kg) reduces osteosarcoma occurrence and increases the average lifetime of animals.

[Effect of BCG vaccination on the incidence of the development of 90Sr-induced osteosarcomas in rats]. / Vliianie vaktsinatsii BTsZh na chastotu razvitiia u krys osteosarkom, indutsirovannykh 90Sr.

The frequency of 90Sr-induced osteosarcoma development was determined in the mongrel rats subjected to BCG vaccination. Injection of BCG (5 mg per animal) is shown to change the frequency of tumour development and their multiplicity only in male rats which were vaccinated 20 days before nuclide administration. An increase up to 10 mg per animal of BCG dose injected 10 days before 90Sr administration caused the carcinogenesis inhibition irrespective of the sex of the animals.

[DNA content of rat organs damaged by strontium-90 during the development of delayed effects]. / Soderzhanie DNK v nekotorykh organakh krys, porazhennykh strontsiem-90 v period formirovaniia u nikh otdalennykh posledstvii.

In this report the results are submitted concerning the frequency of disorders in the nucleic acid metabolism in the bone marrow, peripheral blood, thymus and spleen of rats during a year after single injection of 90Sr. Irrespective of the time lapsed after the injection of the radionuclide 10-30% of animals did not exhibit any substantial changes in the nucleic acid metabolism in all the organs under study except the thymus.

[Application of the Gompertz mortality law to the prognosis of lifespan shortening due to chronic internal irradiation]. / Primenenie zakona smertnosti Gompertsa dlia prognoza sokrashcheniia prodolzhitel'nosti zhizni pri khronicheskom vnutreniem obluchenii.

In experiments on albino rats received strontium 90 in daily doses of 1.85 to 185 kBq/day the regularities of death were studied. It was shown that death of animals exposed to chronic internal radiation followed the Gomperz B. mortality law.

[Long-term effects of chronic irradiation of rats at different dose rates]. / Otdalennye posledstviia khronicheskogo oblucheniia krys pri razlichnoi moshchnosti dozy.

Chronic exposure to ionizing radiation at dose-rates of 1.7 to 13.5 cGy/day has some distinctive features among which the development of radiation affection at the dose rate of 13.5 cGy/day is the main one. At lesser dose rates no qualitative changes in the causes of the animals' death were noted while their quantitative relationship was impaired. The increase in the tumor occurrence was registered at the dose-rate of 3.5 cGy/day. The average life of animals in all groups under study was much shorter than in the controls.

[Incidence of osteosarcomas and the average life span of rats receiving 90Sr]. / Chastota osteosarkom i sredniaia prodolzhitel'nost' zhizni krys, poluchavshikh 90Sr.

In experiments on albino rats exposed to 90Sr (18.5-148 kBq/day) during different periods of time no dependence of the duration of the latent period of osteosarcoma development upon radiation dose was demonstrated.

[Development of long-term radiation effects in rats after whole-body fractionated gamma-irradiation]. / Razvitie otdalennykh posledstvii porazheniia u krys pri obshchem fraktsionirovannom gamma-obluchenii.

Albino male rats were divided into four groups and exposed to gamma-radiation (137Cs) for 80, 40, 20 and 10 days at dose rates of 0.25, 0.5, 1.0 and 2.0 Gy/day, respectively. The development of lesions and remote aftereffects was shown to depend upon conditions of formation of the absorbed dose. With fractionated irradiation at dose rates above 1.0 Gy/day the dose-rate played a major role in producing the effect.