Morphologic changes in the kidneys in acute kidney failure due to acute pancreatitis

Light optical and electron-microscopic investigations were carried out on 42 dogs with experimental hypertensive-enzymatic acute pancreatitis. It was revealed that microcirculatory changes appeared already within the first hour of experimental pancreatitis. By the 4th hour of the experiment the changes in basal membrane and podocytes, as well as proliferation of mesangial cells and growth of mesangial matrix were noted. Thus, at the initial stages of acute pancreatitis morphological alterations in the kidneys correspond to the pattern of mesangial proliferative diffuse glomerulitis.     

Water masses and zooplankton in a tributary of the Rybinsk Reservoir in its backwater zone

In 2008, transition (gradient) and stable zones in backwaters of the tributary of the Rybinsk Reservoir were distinguished according to water conductivity. The highest values of BOD₅ (biochemical oxygen demand) and the maximum zooplankton abundance within the backwater zone as well as in comparison with the neighboring systems (the river and the reservoir) were recorded in the transition zone where the marginal effect appeared.     

Site-specific recombination between phages lambda and phi 81 and integration of hybrid phages lambda-phi 81]

Dependence of the formation frequency of hybrid phages immlambdahphi81 and immphi81hlambda in recombination between phages lambda and phi81 from int-function of both phages is studied. Phages with hybrid att-sites (Plambda OP'phi81 and Pphi81OP'lambda) are isolated and the efficiency of integration of these phages into bacterial chromosome is determined.     

Phyto- and Zooplankton of Open Overgrown Shallows of the Rybinsk Reservoir Adjacent to a Mixed Grey Heron–Great Egret (<Emphasis Type="Italic">Ardea cinerea</Emphasis> L. and <Emphasis Type="Italic">A. alba</Emphasis> L.) Colony at a High Water Level

Phyto- and zooplankton communities developing in the open overgrown shallows of the Rybinsk Reservoir under the influence of a bird colony are shown to lose specific traits of quantitative characteristics and structure fluctuation in response to the elevated water level in contrast to previous findings. Possible reasons, such as the decomposition of sunken coastal vegetation playing the main role, accompanied by the development of semiaquatic macrophytes and trophic relations between algae and invertebrates, are discussed. It is found that increased atmospheric precipitation leads to an increased abundance of Copepoda in the zooplankton. Presumably, this effect correlates with more rapid and intensive inflow of avian vitality products rich in nitrogen into the water, resulting in a change in the stoichiometric ratio of nitrogen and phosphorus in zooplankton food objects to values favorable for copepods.     

Effect of the vital activity products of beaver (<Emphasis Type="Italic">Castor fiber</Emphasis> L.) on the formation of zooplankton structure: Changes in the quantitative parameters of two cladocera species of different sizes in a beaver pound (in situ experiment)

The experiments were performed in microcosms situated on a control site and on a site regulated by beavers. Two cladoceran species of different sizes were placed in microcosms in different proportions. It was found that the vital activity products of Castor fiber L. promote an increase in the concentration of total phosphorus (P), a decrease in the N/P ratio in water, and an increase in the chlorophyll a concentration and the abundance and biomass of bacterioplankton. In such conditions, the abundance and biomass of the large species Daphnia (Ctenodaphnia) magna Straus was increased to the greatest extent when compared with background values when it was placed in combination with Ceriodaphnia dubia Richard or without it. Moreover, in the case of the combination of two crustacean species in microcosms, the abundance of C. dubia was lower when compared with the control site, while the abundance of D. magna was higher. The results of a bioassay showed that the productivity of C. dubia decreases in waters where D. magna is most abundant. We concluded that the formation of zooplankton in beaver ponds with specific features determined by the presence of large cladoceran species is provided by changes in the quantitative and qualitative parameters of food resources. This contributes to the massive distribution of large D. magna and its competitive relations with small C. dubia. According to the results of a bioassay, the vital activity products of D. magna can inhibit the fecundity of C. dubia.