[Separate and combined mutagenic effect of radiation and asbestos on the micronucleus test in experiments]. / Razdel'noe i sochetannoe mutagennoe deistvie radiatsii i asbesta v mikroiadernom teste v éksperimente.

We investigated the isolated and combined mutagenic effect (ME) of radiation (gamma-irradiation, 0.5 or 2 Gy) and asbestos (i.p. 10 mg/mice) in mice CBA. We studied also the antioxidant activity and malonic dialdehyde concentration in blood serum as possible mechanism of ME and its possible modification. For the ME the micro-nuclei incidence in polychromatic bone marrow erythrocytes was scored. The reciprocal modification (potentiation) of both radiation and asbestos ME was established for combination "radiation, 2 Gy + asbestos", the additivity--for combination "radiation, 0.5 Gy + asbestos".

[Modified effect of dust and chemical mutagens under the influence of vibration]. / Modifikatsionnyi éffekt pylevogo i khimicheskikh mutagenov pod vozdeistviem vibratsii.

The impact of transport vibration on the mutagenic effect (ME) of asbestos, benzo(a)pyrene (BaP), benzene, ortho-aminotoluene, and quinoline was studied. There was a decrease in ME of all the substances when they influenced erythrocytes simultaneously with 24-hour vibration. Decreased ME of BaP was seen during 2-month vibration, and ME increased during 3-day vibration.

[Effects of coal tar on hematological parameters in experimental tuberculosis]. / Vliianie kamennougol'noi smoly na gematologicheskie pokazateli pri éksperimental'nom tuberkuleze.

Guinea pigs were injected with coal tar (CT) (intratracheally, 25 mg per animal once a week or a month for 2 or 8 months, respectively), then they were infected with MBT (H37Rv, 0.1 mg, subcutaneously). There were changes in hematological responses to MBT changes (in the context of the cell composition of bone marrow and peripheral blood), their pattern was associated with the mode of exposure to CT preceding MBT inoculation. The greatest differences were found in the responses of bone marrow lymphopoiesis and peripheral lymphocytes upon both exposures to CT. On greater exposure to CT (once a week) the changes in the blood system indicated that CT had an adverse effect on the course of experimental tuberculosis, while on lesser exposure (once a month), the effect of CT was more favourable.

[Mutagenic effects of asbestos modified by association with ethanol, coffee and tobacco tar]. / Modifikatsiia mutagennogo deistviia asbesta pri sochetanii s étanolom, kofe i kuritel'noi smoloi.

The study covered possible modification of mutagenic action of asbestos in combination with widespread agents--ethanol, coffee extractive and fumigating resin. Such modifying effects as antagonism, synergism were revealed as well as an independent action. An attempt was made to extrapolate the obtained data to human exposure to asbestos.

[The oncogenic action of nonfibrous mineral dusts]. / Ob onkogennom deistvii nekotorykh nevoloknistykh mineral'nykh pylei.

Nonfibrous mineral dusts antigorite, basalt, cement, zeolite-klinoptilolite and gamma-alumina were tested for carcinogenic activity in rat experiments. Intraperitoneal injections of zeolite-klinoptilolite and gamma-alumina led to development of peritoneal mesotheliomas, whereas antigorite and cement had no carcinogenic potential. There is no differences in physicochemical and chemical properties between carcinogenically active and inactive nonfibrous dusts. A new class of carcinogenic substances is defined including basalt, zeolite-klinoptilolite and quartz which belong to nonfibrous mineral dusts.

[Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos]. / Sravnitel'naia onkogennost' bazal' tovykh volokon i khrizotil-asbesta.

In order to eliminate asbestos adverse effect on workers' health it was necessary to use mineral rayon, primarily basalt fibre, instead of asbestos. During a chronic experiment on animals the oncogenicity of 2 kinds of basalt fibre was studied compared to chrysotile asbestos. The dust dose of 25 mg was twice administered by intraperitonial route. All types of dust induced the onset of intraperitonial mesotheliomas but neoplasm rates were significantly lower in the groups exposed to basalt fibre. There was no credible data on the differences between the groups exposed to various types of basalt fibre. Since the latter produced some oncogenic effect, it was necessary to develop a complex of antidust measures, fully corresponding to the measures adopted for carcinogenic dusts.

[Induction of immunologic deficiency by benzene and its correction by administration of anabol]. / Induktsiia immunodefitsita benzolom i ego korrektsiia vvedeniem anabola.

Cellular immunity and activity of enzymes of xenobiotic metabolism have been investigated. It has been shown that administration of benzene induces a stable immune deficiency syndrome characterized by a decrease in the quantity if antibody-forming cells, T-killers and T-suppressors. The activity of enzymes (cytochrome P-450 and cytochrome C reductase) was also inhibited. It has been shown that anabol can stimulate the parameters of cellular immunity and enzyme activity. Benzene intoxication was demonstrated to be a model of immune deficiency syndrome similar to the clinical pattern. Anabol was shown to be an effective immunomodulator.

[Cellular immunity and enzyme activity of xenobiotic metabolism in the lymphocytes of normal minipigs and in alcohol and anabol exposures]. / Kletochnyi immunitet i aktivnost' fermentov metabolizma ksenobiotikov v limfotsitakh u mini-svinei v norme i pri deistvii alkogolia i anabola.

Immunological indices and activity of xenobiotic metabolism enzymes in lymphocytes were studied on minipigs under normal conditions, under conditions of chronic alcoholic intoxication and after administration of anabol (an immunomodulator) to normal healthy animals and to animals with alcohol intoxication. Age-related differences with respect to the number of T-lymphocytes and activity of lymphocyte glutathione S-transferase were observed in the normal animals, the other indices such as activity of natural killer cells, K-cells, blast cell transformation with concanavalin A and activity of cytochrome c-reductase being independent of the age. Administration of anabol to healthy animals did not alter their immunoenzymatic status. Chronic alcohol intoxication was accompanied by development of secondary immune deficiency characterized by lower immunological indices and lower activity of xenobiotic metabolism enzymes in lymphocytes. Daily exposure to 0.8 g of anabol for 12 days at this background resulted in normalization of the above indices.

[Micronucleus test as a short-term assay for detecting the potential carcinogenicity of different groups of chemical compounds]. / Mikroiadernyi test kak kratkosrochnyi metod vyiavleniia potentsial'noi onkogennosti razlichnykh grupp khimicheskikh veshchestv.

Certain theoretical aspects of the method, the normal level of micronuclei in polychromatic erythrocytes of bone marrow cells in different animals species, the data obtained for the different types of chemical compounds are analyzed as well as the possibility of obtaining false-negative and false-positive results. This method is found to be very promising and needs further development in the near future.

[Effect of benzene on the content and proliferative activity of reticular cells in the hematopoietic organs]. / O vliianii benzola na soderzhanie i proliferativnuiu aktivnost' retikuliarnykh kletok v krovetvornykh organov.

Experiments were conducted on albino rats, CBA mice and rabbits. The experimental benzol poisoning caused insignificant changes in reticular cell proliferation without any changes in the level of these cells in bone marrow and spleen. It was shown also that the level of reticular cells play a certain role in resistance and activity of erythropoiesis and in the production of colonies by stem cells.

[Effect of erythrocyte breakdown products on mast cells and erythropoietin formation]. / Vliianie produktov raspada éritrotsitov na stvolonye kletki i obrazovanie éritropoétina.

Experiments were conducted on CBA mice and albino rats. A study was made of the effect of erythrocyte destruction products (EDP) on the content of hemopoietic colony-forming units (CFU), differentiation of stem cells and the erythropoietin production. It was shown that 3 or 4 EDP injections to normal mice or to lethally irradiated (1000 rad) mice after the transplantation of bone marrow cells caused no changes in the CFU level of stem cells differentiation. In case of a daily (for 3 days) administration of EDP to mice before the irradiation (1000 rad) and bone marrow transplantation there was observed an increase of the colonies count in the recipients' spleen on account of the erythroid colonies. EDP injection caused no changes in the erythropoietic activity of the blood serum. A possible role of erythrocyte destruction products in the mechanism of erythropoiesis autoregulation is discussed.