[Cytogenetic effects of alpha-irradiation due to incorporated 239Pu]. / Tsitogeneticheskie éffekty alpha-oblucheniia inkorporirovannykh 239Pu.

Intravenous injection of plutonium dioxide with 1-2 microns particle sizes in amount of 92.5, 46.3 and 23.2 kBq/kg of body mass increased the yield of chromosome aberrations in bone marrow cells of rats by 3.7, 2.3 and 1.7 times, correspondingly, in comparison with the spontaneous level. The model of chromosome aberration dependence on dose of radionuclide was developed based on the experimental results.

[Frequency of structural chromosome aberrations in the hepatocytes of rats exposed to polymeric 239Pu]. / Chastota strukturnykh povrezhdenii khromosom gepatitsitov krys pri deistvii polimernogo 239Pu.

Intravenous injection of polymeric 239Pu(IV) nitrate (166.5, 55.5 and 18.5 kBq/kg body mass) to Wistar rats was shown to produce biphase changes in the frequency of hepatocyte chromosome aberrations. The increase in the structural damages to chromosomes at later times of observation was a pronounced function of radiation dose. The absence of such a dependence at early times was evidently due to the elimination of damaged liver parenchyma cells.

[The frequency of chromosome aberrations in rat bone marrow cells in the late period after a single uptake of tritium]. / Chastota aberratsii khromosom kletok kostnogo mozga krys v otdalennom periode posle odnokratnogo postupleniia tritiia.

A prolonged self-maintenance of haemopoietic tissue cells with stable chromosome rearrangements following a single intake of tritium oxide in the amount of 24 MBq/g of body weight (absorbed dose of 11 Gy) is shown. Mutant cells revealed long after the radionuclide exposure are descendants of stem-cell precursors, bearing stable chromosome aberrations during the period of formation of radiation injury after the radionuclide administration.

[Structural chromosomal damages in myelokaryocytes exposed to plutonium-239 dioxide]. / Strukturnye povrezhdeniia khromosom mielokariotsitov pri deistvii dvuokisi plutoniia-239.

Plutonium 239 dioxide, with particle sizes of 1-2 micron, injected to Wistar rats intravenously in doses of 92.5, 46.3, and 23.2 kBq/kg body mass, increased the frequency of chromosome aberrations in myelokaryocytes by 3.7, 2.3 and 1.7 times, respectively, compared to spontaneous levels.

[Frequency of chromosome aberration in liver cells of rats of various ages]. / Chastota aberratsii khromosom v kletkakh pecheni krys raznogo vozrasta.

Frequency of chromosome aberrations in the liver cells of hepatectomized Wistar rats aged 3, 9, 12 and 18 months was studied. Changes in the number of chromosomes and damage of their structure at the metaphase stage of the first division hepatocytes are analyzed. The content of aneuploid cells was 1-3% of the total number of metaphases studied and did not change with the age of animals. Frequency of chromosomal aberrations increased with aging from 1.3 to 6.9 in rats aged 3 and 18 months, respectively, mainly due to chromatid-type aberrations.

[Determination of the efficiency of reparative processes in the chromosomes of bone marrow cells in vivo by using test irradiation]. / Opredelenie éffektivnosti reparativnykh protsessov v khromosomakh kletok kostnogo mozga in vivo s pomoshch'iu test-oblucheniia.

The method developed on rats was applied to estimate the effectiveness of reparative processes in myelokaryocyte chromosomes using the test-irradiation in vivo (0.5 Gy, gamma-rays of 137Cs). The method is based on the comparison of the curves demonstrating the chromosome aberration yield in the first mitosis following the test-irradiation of experimental and control animals.

[Chromosome structural damages to the myelokaryocytes of rats in late periods after chronic exposure to tritium and external gamma irradiation]. / Strukturnye povrezhdeniia khromosom mielokariotsitov krys v pozdnie sroki posle khronicheskogo deistviia tritiia i vneshnego gamma-oblucheniia.

A pronounced variation in the total amount and spectrum of chromosome aberrations of rat myelocarycytes was found at later times following long-term exposure to tritium oxide and external gamma-radiation (137Cs). Cells with atypical chromosomes (symmetrical exchanges) were 1.5-2 times more frequent in bone marrow of tritium-treated rats throughout the entire lifetime.

[Seasonal radiosensitivity of rats and dogs]. / Sezonnaia radiochuvstvitel'nost' krys i sobak.

The data are submitted obtained on 10.5 thousands Wistar rats and 350 mongrel dogs exposed to gamma-radiation (LD40-LD100) in different seasons. The radiosensitivity of both animal species was the highest in autumn (August and September) and the lowest in winter (February and January). The seasonal DMF for rats and dogs with LD16, LD50 and LD84 was 1.24 and 1.31, 1.13 and 1.17 and 1.04 and 1.07, respectively. The curves for seasonal radiosensitivity of dogs with LD84, LD50 and LD16, exhibited a single--phase character throughout a year. For rats, the seasonal radiosensitivity curves with LD84 were single-phase, and the curve with LD50, and particularly LD16, exhibited the second peak of radioresistance in June. The increase in radioresistance of rats and dogs correlated with the increase in number of leukocytes in the peripheral blood of animals.