[Separate and combined mutagenic effect of radiation and asbestos on the micronucleus test in experiments].

We investigated the isolated and combined mutagenic effect (ME) of radiation (gamma-irradiation, 0.5 or 2 Gy) and asbestos (i.p.

[Modified effect of dust and chemical mutagens under the influence of vibration].

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].

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.

[Mutagenic effects of asbestos modified by association with ethanol, coffee and tobacco tar].

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].

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.

[Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos].

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.

[Induction of immunologic deficiency by benzene and its correction by administration of anabol].

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.

[Cellular immunity and enzyme activity of xenobiotic metabolism in the lymphocytes of normal minipigs and in alcohol and anabol exposures].

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.

[Micronucleus test as a short-term assay for detecting the potential carcinogenicity of different groups of chemical compounds].

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].

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].

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.

[Role of destruction products of tissue macrophages in regulating granulocytopoiesis].

Peripheral blood leukocytosis and an increase of mature forms of neutrophils and monocytes in the bone marrow, as well as an improvement of the oxygen supply of the bone marrow cells (by the data of polarographic studies) followed the intraperitoneal injections of rat peritoneal macrophage destruction products (MDP) to the recipient rats. Analogous changes were obtained in the bone marrow in case of intraperitoneal injection of the cytotoxic quartz dust particles. Having been injected intraperitoneally to donor CBA mice, the MDPs strikingly stimulated the glanulocytopoietic colonies formation in the spleen of the recipient CBA mice X-irradiated with a lethal dose and then injected intravenously with the bone marrow of spleen tissue suspensions obtained from the donors.