[MONITORING OF THE CONTENT OF HEAVY METALS AND ELEMENTS IN THE SNOW COVER IN AGRICULTURAL SOILS AT THE TERRITORY OF THE MOSCOW REGION].

The monitoring of snow cover pollution by heavy metals and elements (zinc, copper, lead, cadmium, arsenic, nickel, chromium, strontium, manganese, fluorine, lithium) was performed in 20 districts of the Moscow region in 2009, 2012 and 2013. The assessment of the levels of contamination by heavy metals and elements was given by means of comparison of them with the average values in the snow cover near Moscow in the end of the last century and in some areas of the world, that no exposed to technological environmental impact. 7 districts of Moscow region were characterized by a high content of lead and cadmium in the snow water. It requires the control of water, soil and agricultural products pollution.

Structural organization of glial cells at the border between the neurotransplant and recipient brain.

Integration of fetal hippocampal dentate fascia neurotransplants with the neocortical somatosensory region in adult rats was studied by electron microscopy. The growth of nerve fiber through the neurotransplant/brain border formed by the glial cells was studied. The interface zone was organized by various astrocyte subpopulations and ependymocytes forming multilamellar accumulations in some sites of the interface. These conglomerations of the glial cells and their processes did not prevent the growth of axonal and axodendritic bundles; moreover, fibrous astrocyte axons accompanied them. Under conditions of immature nervous tissue transplantation to the focus of mature brain damage, the glial cells created a substrate in the interface permeable for nerve fibers, thus promoting the functional integration of the neurotransplant.

[Monitoring of the chemical composition of snow cover pollution in the Moscow region].

Monitoring of snow cover pollution as an indicator of ambient air pollution in 20 districts in the Moscow region during 2009-2013 was performed. The identification with a quantitative assessment of a wide array of organic compounds and the control of the main physical and chemical and inorganic indices of snow water pollution were carried out. More than 60 organic substances for most of which there are no the hygienic standards were established. The assessment of pollution levels of basic inorganic indices was given by means of the comparing them with the average values in the snow cover in the European territory of Russia and natural content in areas not been exposed to human impact.

[Electrothermal atomic absorption determination of arsenic in plants and plant products].

The authors have developed the optimal temperature-time parameters of electrothermal atomic absorption determination of arsenic in plants after their acid predigestion. The matrix modifier is 1% nickel nitrate or palladium nitrate solution. Cuvettes (ovens) are simple, made of porous or pyrolytic graphite. The analytical program is suitable for both spectrometers with Zeeman and deuterium background correction. The correctness of the procedure has been estimated from the results of analysis of state reference samples certified for their arsenic content. The coefficient of variation was 20-35% for the concentration range of 0.02-0.2 mg/kg.

[Participation of puncta adherentia junctions in the formation of synaptic connections between a dentate fascia graft and the host brain].

The fetal dentate fascia of Wistar rats on the 20th day of gestation was heterotopically grafted into the somatosensory neocortex of adult rats. Granule cells of a graft projected their axons (mossy fibers) to the host brain and established synaptic contacts with inappropriate targets. The organization of ectopic mossy fiber synapses was studied by electron microscopy. It was shown that ectopic synapses reproduce the structural determinants of hippocampal giant synapses and induce a subcellular reorganization of postsynaptic neocortex dendrites. Using morphometric analysis, a significant increase was found in the number of discrete puncta adherentia junctions and their total length in ectopic synapses as compared with the control group. The data obtained indicate that puncta adherentia contacts participate in the structural and chemical adaptation of neuronal targets to alien axons growing from transplants.

Involvement of neuropeptide mechanisms in the process of integration of heterotopic dental fascia transplants with recipient brains.

Embryonic dentate fascia was transplanted into the somatosensory area of the neocortex of adult rats. Ultrastructural and morphometric analyses of giant synapses formed by the granule neurons of transplants with inappropriate neuronal targets in the recipient brains were performed after nine months. As compared with intact synaptic terminals in the control hippocampus, there were differences in the quantity and distribution of large synaptic vesicles with electron-dense centers storing neuropeptide cotransmitters. The proportion of peptidergic vesicles (of the total number of vesicles) in ectopic giant synapses was 5.8 +/- 0.6%, compared with 3.3 +/- 0.6% in controls. Accumulations of large, dense vesicles close to the active zones of aberrant connections were seen almost 7.9 times more often than in controls. These results show that neuropeptide transmitters are critical for maintaining synaptic connections between heterotopic dentate fascia transplants and recipient brains.

[Involvement of neuropeptide mechanisms in the integration of heterotopic dentate fascia grafts and recipient brain].

Embryonic dentate fascia was grafted into the somatosensory neocortex of adult rats. Nine months post-grafting, the ultrastructural and morphometric analysis of the giant synapses established between the grafted granular neurons and inappropriate targets in the recipient brain was performed. As compared to the intact synaptic endings in the control hippocampus, differences were found in both the number and distribution of large dense-core synaptic vesicles, which store the neuropeptide co-transmitters. The peptidergic vesicle proportion (of total vesicle pool) within the ectopic giant synapses was 5.8 +/- 0.6% (versus 3.3 +/- 0.6% in the control). Clusters of large dense-core vesicles near the active zones of aberrant connections were observed almost 7.9 times more frequently than that of normal contacts. These data provide evidence that neuropeptide transmitters are critical for the maintenance of synaptic connections between the heterotopic dentate grafts and host brain.

[Radionuclide transfer by migratory birds]. / Perenos radionuklidov pereletnymi ptitsami.

Evaluation of the zoogenic transfer of radionuclides from the 30-km zone around the Chernobyl NPP was necessary because of the enormous heavily polluted territory and mighty flow of migratory birds who tended to large rivers, the Dnieper and Pripyat. The integral estimate of the transferred amount was obtained as a product of three variables: the transfer factor (0.0077 m2/kg for 137Cs; 0.0107 m2/kg for 90Sr), the density of birds (0.002 kg/m2, at the mass of migrants about 5000 t per year), and the total fund of radionuclides throughout the territory. The upper estimated limit of the annual transfer rate was 5.5 Ci (2E + 11 Bq) for 137 Cs and 1.8 Ci (6.7E + 10 Bq) for 90 Sr. Restrictions of hunting are recommended within the northern part of the Kiev reservoir.