Changes in the migration and adhesive activity of polymorphonuclear leukocytes as 1 of the characteristics of Gram-negative bacteria isolated from patients with suppurative lung destruction

The influence of Gram-negative bacteria on the migratory and adhesive activity of polymorphonuclear leukocytes (PMNL) in the peripheral blood of clinically normal donors has been studied by the specially developed method with the use of Boyden chambers. Pseudomonas and enterobacteria have been found to produce complex and various effects on the above-mentioned properties of PMNL. When incubated in fresh serum, Gram-negative bacteria are capable of enhancing the migratory activity of PMNL, this property being least pronounced in P. aeruginosa. The incubation of live bacteria from the authors' collection in the patients' sera or in sera obtained from normal donors and inactivated by heating induces no hemotaxis of PMNL, and P. aeruginosa strains even suppress it under such conditions. The isolated Gram-negative bacteria under study increase the number of highly adhesive PMNL in the population used in this investigation, but P. aeruginosa cultures do not produce such effect.     

Regulation of apolipoprotein expression]

Recent data and concepts on the structure and functioning of apolipoprotein genes as well as on the role of hereditary factors in pathogenesis of atherosclerosis are reviewed. The most important variants of inherited disorders in the system of apolipoproteins promoting the development of atherosclerosis are considered. Special attention is paid to the RFLP of apolipoprotein genes which serves as a peculiar genetic background, increasing probability of the atherosclerosis development in certain individuals.     

The cellular mechanism for the formation of lamellar bodies in type-II pneumocytes in rat lungs]

Pneumocyte type II cells from lungs of native rats and of rats that inspired a hypoxic mixture of gases were investigated by transmission electron microscopy. In cells of experimental rats, membrane structures were found that well compare with lamellar bodies. Experimental results and analysis of literature allowed to put forward a hypothesis about the cell mechanism of formation of lamellar bodies from the spiral twisted membranes of the endoplasmic reticulum.     

Contributions of expression redistribution and allele substitutions to the genetic differentiation of animal taxa of different ranks

The contributions to the genetic differences between animal taxa of various ranks were estimated for four groups of loci: loci with identical (i), similar (s), or completely different (d) allele compositions, and (o) loci displaying a change in expression. The main contribution is made by i-and s-loci at the intraspecific level. Another pattern is observed at the specific level: d-loci become dominant and o-loci appear, suggesting fundamental changes in the genomes upon speciation. The relationships between the contributions of the four groups of loci are relatively stable within a class and differ among classes. Interestingly, the extent of genetic differentiation (as estimated from the proportions of the above four components) observed at the specific level in amphibians is achieved only at the level of families in birds. The approach is especially efficient for identifying hybrid populations and individuals.     

Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Extramedullary hematopoiesis in a case of benign mixed mammary tumor in a female dog: cytological and histopathological assessment

Backgroud  

Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case.     

Quantitative evaluation of the genetic divergence of amphibian taxa of different rank by the spectra of total proteins and nonspecific esterases

Based on the PAAG disc-electrophoretic spectra of water-soluble total proteins (Pr) and non-specific esterases (Est) from several types of tissues in representatives of Urodela (Triturus vulgaris vulgaris, T. v. lantzi, T. cristatus, T. montandoni, T. dobrogicus) and Anura amphibians (Rana ridibunda, R. lessonae, R. temporaria, R. arvalis; Bufo bufo, B. viridis, Bombina bombina; Xenopus laevis, X. borealis; Hymenochirus boettgeri), mean genetic distances (D = -ln[2i/(2i + d)], where i is the number of fractions identical and d is the number of fractions different by Rf-bands, were estimated within and between taxa of intra-, inter-, and superspecific ranks. The most stable estimates were obtained for Pr and Est spectra of skeletal muscles and eyes. In most cases, the spectra of tissues of the digestive system gave higher D values than those of the other organs. The levels of intraspecific differentiation by D (both Pr and Est) were higher in the studied representatives of the order Urodela, probably due to their lower migration ability and more conservative choice of water-bodies for spawning than in the representatives of the other order; the same trend is true for the interspecific differentiation by Pr spectra. Est, on the contrary, gave lighter interspecific differentiation level in Anura than in Urodela, evidently due to the prevalence of sympatric species pairs able to hybridize among the studied representatives of the latter order.     

Testate amoebae communities in the southern tundra and forest-tundra of Western Siberia

The species composition and community structure of soil-inhabiting testate amoebae communities have been studied in biotopes of different types in the southern tundra and forest-tundra of the Tazovskaya Lowland, Western Siberia. A total of 93 species and forms have been identified. It has been found that the species richness of testate amoebae is much lower in dry than in moist biotopes due to a lower level of beta-diversity, with alpha diversity being the same (on average, 16.9 and 17.1 species per sample, respectively). Factors acting at the microbiotope level (biotope type and moisture) play the most important role in the formation of species richness; biotope features (soils and vegetation) are second in importance. In moist habitats, local communities of testate amoebae from different microbiotopes (mosses, lichens, or litter) are fairly similar in species structure, and communities from different moist biotopes are heterogeneous. In dry areas, the opposite situation is observed: local communities differ at the microbiotope level but are similar at the biotope level. The abundance of testate amoebae in moist biotopes reaches 200 × 10³ ind./g dry soil, being an order of magnitude lower in dry biotopes.