[Influence of synthetic peptide of active GM-CSF center on hemopoiesis recovery in C57Bl/6 mice after exposure to fractionated radiation].

The research allowed evaluation of the influence exerted by synthetic peptide of the active center of granulocyte-macrophage colony-stimulating (GM-CSF) factor on hematopoiesis in mice both under normal physiological conditions of the animals, and during the period of post-exposure recovery of hematopoiesis. It has been demonstrated that a synthetic peptide of the active GM-CSF center is able to exert a stimulating effect on animals with radiation-induced hematopoiesis inhibition. A single injection of the preparation at a dose of 0.005 µg/g to female C57Bl/6 mice, which had been exposed to fractionated exposure at a dose of 10 Gy and developed inhibition of bone-marrow hematopoiesis and cytopenia, exerted a stimulating effect on the granulocyte and monocyte lineages of hemopoiesis. Injections of an active GM-CSF center peptide to irradiated animals did not influence the content of CFUs in thebone-marrow (BM), but they exerted a stimulating influence on the population of these cells in unexposed animals. No effect of the influence of the preparation on the development of extramedullary hematopoiesis in the spleen was observed in the irradiated mice. The study showed that a peptide active site GM-CSF is a promising drug in terms of its use for the treatment of radiation-induced myelosuppression.

[Experimental assessment of combined effect of nitrates and acute gamma-irradiation on green algae Scenedesmus quadricauda growth].

The combined effect of acute gamma-irradiation at doses of 0, 50, 100, 150 and 200 Gy and nitrates in concentrations of 0.04 g/dm3 (that corresponds to maximum permissible concentrations for fishery waters), 0.1, 0.25, 0.5, 1.0, 2.5 g/dm3 (that is close to NO3(-) level in water of a reservoir R-17 used as radioactive waste storage of the "Mayak" Production Association) and 5.0 g/dm3 (that is close to NO3(-) level in the water of radioactive waste storage reservoir R-9) on the unicellular green algae Scenedesmus quadricauda growth has been studied in laboratory conditions. It was shown that the joint effects of nitrates and y-radiation had an antagonistic character. Thus, it may be concluded that chemical pollution is the factor limiting the development of green algae in reservoir R-17; probably, both factors, chemical and radiating, are essential to the algocenosis degradation in reservoir R-9.

[Assessment of radiation exposure level for hydrobionts in some special industrial ponds at the "Mayak" PA].

Evaluation of the radionuclide content in the ecosystem components (water, sediments, aquatic organisms) of industrial reservoirs-storages of liquid radioactive waste of the "Mayak" PA (reservoirs R-4, R-10, R-11, R-17, R-9) and the estimation of the absorbed dose rate in aquatic organisms of these reservoirs using the software package ERICA Assessment Tool 1.0 May 2009 have been performed. Gradient of the absorbed dose rate for the detected taxonomic groups of hydrobionts in the series of the studied reservoirs R-11 --> R-10 --> R-4 --> R-17 --> R-9 was almost equal to one order of magnitude. The estimated absorbed dose rate for phytoplankton ranged from 5.4 x 10(0) mGy/day (R-11) to 4.0 x 10(4) mGy/day (R-9), for zooplankton--from 6.4 x 10(-1) mGy/day (R-11) to 3.8 x 10(3) mGy/day (R-9), for zoobenthos (chironomids)--from 5.6 x 10(0) mGy/day (R-11) to 1.1 x 10(3) mGy/day (R-17), for fish (roach)--from 8.0 x 10(-1) mGy/day (R-11) to 1.9 x 10(1) mGy/day (R-4).

[Analysis of DNA damage/repair level in Rutilus rutilus L. from reservoirs of the Techa River cascade with different levels of radiactive pollution].

The Comet Assay and micronucleus assays have been used to evaluate the condition of the nuclear DNA in erythrocytes of peripheral blood of roach (Rutilus rutilus L.) from water-storage of low-level radioactive waste. The Rutilus rutilus L. from the Shershny reservoir, Chelyabinsk, was used as a control population. Radionuclide maintenance in water, sediments and roach in those reservoirs and Shershny reservoir was defined. The dose rate for Rutilus rutilus L. was calculated using program complex ERICA Assessment Tool 1.0 May 2009. Our investigation has shown that a chronic radiation of population (dose rate - 5.2 mGy/day and 19.5 mGy/day) leads to a significantly higher level of the DNA damage in erythrocytes of peripheral blood and increases the speed of nuclear DNA reparation after irradiation of erythrocytes in vitro. We suppose that it may be a result of the increased quantity of active form of oxygen in cells of the fish in water-storage of low-level radioactive waste.

[Assessment of erythrocytes pathology level in peripheral blood in roach (Rutilus rutilus L.) from reservoirs with different levels of radioactive contamination].

In summer 2009, the level of pathology of erythrocytes was assessed in the peripheral blood of roach (Rutilus rutilus L.) from the reservoirs for water-storage of low level radioactive waste of PA "Mayak". Roach from the Shershny reservoir and the Buffer reservoir (Chelyabinsk region) was used as a control. Radionuclide maintenance in water, sediment, and roach was determined and dose rates for the roach were calculated using the software package ERICA Assessment Tool 1.0 May 2009. It is revealed that chronic radiation exposure with the dose rates in the range from 0.8 up to 19 mGy/d leads to a twofold increase in the frequency of erythrocytes with micronuclei in peripheral blood, dose-dependent increase in the frequency of red blood cells with the nuclear pyknosis and causes no significant increase in the level oferythrocyte amitosis. It is suggested that the frequency rate of apoptosis in peripheral blood erythrocytes of the fish could be used in the biological monitoring of contaminated aquatic ecosystems.

[Phytoplankton in reservoir R-11 of Techa reservoir cascade of Industrial Association "Maiak"].

Phytoplankton of reservoir R-11 was investigated at vegetative seasons of 2007 and 2008. R-11 is a locking reservoir in the cascade of Mayak PA reservoirs. The specific activity in water of R-11 ranged from 0.9 to 1.8 kBq/dm for 90Sr and from 0.98 to 3.97 kBq/dm3 for 137Cs; in bottom sediments it ranged from 20 to 400 kBq/kg for 90Sr and from 0.35 to 220 kBq/kg for 137Cs. Concentration of SO4- exceeded the maximum permissible concentration for fishing reservoirs in 5-7 times. The content of 90Sr in the phytoplankton has made 400 kBq/kg (for dry weight), and 137Cs--2.20 kBq/kg (for dry weight). The absorbed dose of irradiation for the phytoplankton calculated under the content of 137Cs and 90Sr in water and in phytoplankton (the external irradiation from activity of bottom sediments was not considered) has made 901 mGy per year. Altogether the phytoplankton of reservoir R-11 included 107 species. Such species of Cyanobacteriae as Oscillatoria agardhii Gom. was the dominant in phytoplanktonic community. Another Cyanobacteriae, Lyngbya limnetica Lemm. and Aphanizomenonflos-aquae (L.) Ralfs. acted the most important part in a complex of species-subdominants. According to quantitative development of the phytoplankton the reservoir R-11 can be classified as P-mezosaprobe waters.

[Effect of toxins of cyanobacteria of the Microcystis genus from the Shershnevo Reservoir on DNA, cell cycle, and apoptosis of bone marrow cells in CBA mice].

The effect of toxins of a Cyanobacterium sample of the Shershnevo Reservoir on DNA, which was presented by cyanobacteria of the Microcystis genera, on the bone marrow of male CBA mice (whose age was 3 months and weight 24 g) was evaluated. With intraperitoneal administration, LD50 and LD16 of this sample for male CBA mice were 48.4 and 42.1 mg/kg, respectively. Administration of Microcystis cyanobacterial sample from the Shershnevo Reservoir in doses of 1/10 of LD16 and 1/2 of LD16, and LD16 was found to cause a dose-dependent reduction in the number of bone marrow nucleated cells, a dose-dependent increase in the rate of cell apoptotic death, a reduction in the duration of a cell cycle (within the first 12 hours), which gave way to an increase in the duration of the cycle 24 hours after administration, a dose-dependent increase in the frequency of micronuclei in the murine bone marrow eryphrocytes, and a dose-dependent decrease in the polychromatophil/normochromatophil ratio in the murine bone marrow.

[Evaluation of the toxic properties of cyanobacteriae of the Shershnevo water storage basin in the Chelyabinsk Region].

The toxic properties of cyanobacteriae of the Shershnevo water storage basin have been studied. Over almost the whole vegetative period of 2005, the cyanobacteriae of the Shershnevo water storage basin may be characterized as high toxic (when intraperitoneally injected to male CBA mice, LD50 was less than 100 mg/kg). There were no interspecific differences between the noninbred animals in cyanotoxin susceptibility. Gender differences were revealed in cyanotoxin susceptibility in CBA and noninbred albino mice: quantitative differences in LD50 (males/females) were 1.34 in CBA mice and 1.3 times in noninbred albino mice. The cyanobacteriae of the Shershnevo water storage basin were found to have an irritating effect on the skin and ocular mucosa. It is suggested that the toxins of Shershnevo water storage basin cyanobacteriae may have a damaging effect on human beings.

[The assessment of modulated radiofrequence electromagnetic radiation on cognitive function in rats of different ages].

The modulated radiofrequence electromagnetic radiation influence on cognitive function of male uninbred Wister rat exposed at the age of sexual maturation (2 months) and at the age of morphofunctional maturity (3.5 months) was examined. Animals were subjected to pulse electromagnetic radiation (925 MHz) modulated as a GSM standard with the power density 1.2 mW/cm2 for 10 minutes every day for 12 days. At day 8 of exposure the cognitive function were examined with the Morris water maze. In the result of investigation it was determines that modulated radiofrequence electromagnetic radiation at the sexual maturation age did not affect the spatial learning and improve the visual orientation performance. Modulated radiofrequence electromagnetic exposure of animals at the sex maturity age did not affect the visual performance and improve the spatial performance of male rats.

[Assessment of hemapoietic system reaction of mice when exposed to pulsed magnetic field].

The focus of the study was on the reaction of by the haemopoietic system of mice subjected to impulse magnetic field. The source of the impulse magnetic field was the Shakhparonov's generator. The animals used in the experiments were mice of two strains--CBA, C57B1/6 and white non-inbred mice. These animals were exposed to impulse magnetic field during 1, 3 and 7 days. Animals were examined twice: immediately after the termination of exposure and 24 h later. The following effects were observed in the course of the experiments: an increase in the number of bone marrow cells right after the exposure termination; an increase in the number of proliferation pool cells with the increase in their mitotic activity; 1 day after the exposure termination the number of bone marrow cells was restored to the initial values, or even it decreased; the above listed bone marrow changes led to the increase in the number of peripheral blood leucocytes in 1 day after the termination of exposure. The increase of leukocyte counts was not accompanied with changes in peripheral blood cell composition. It was suggested that exposure to impulse magnetic field increases the rates of cell cycle, the cell differentiation and the maturation.

[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.