Vol 142, No 4 (2012)

The aim of this work was to determine, on the basis of the results of authors' own research and literature data, the main pathways of osteocyte (OC) influence on the mechanical homeostasis of the skeleton. The following pathways of reorganization of the architecture of bone structures are postulated: at the ultrastructural level without direct cell participation, through the bone matrix synthesis by osteoblasts and OC, through bone matrix resorption by osteoclasts and OC, the latter being able to resorb the surrounding mineral and organic matrix both separately, and conjointly. This reorganization results in local changes of the mechanical characteristics of bones due to changes in: porosity of interstitial spaces, transport ability of the lacunar-canalicular system, porosity of the area of osteoblastic-osteoclastic remodeling, modeling of bone structures. From the point of view of adaptation theory it is highly significant that the subtle local control of bone structures is able to induce changes in the parameters of the mechanical environment, which, on the one hand, would correspond to OC metabolic requirements and, on the other hand, would support the parameters of body mineral homeostasis.

Nestin and Musashi1 (Msi-1) proteins are most often used for labeling of neural stem cells and progenitor cells in vivo, however it remains unclear if these markers really label the same cells. As a result of the study of structural characteristics and localization of nestin- and Msi1-expressing cells it was found that these proteins were detected in non-identical cell populations in the brain of intact 15 rats. We failed to find cell groups demonstrating a coexpression of nestin and Msi-1. However, after ischemic lesion of the brain, which was caused in 38 rats by an endovascular occlusion of the left medial cerebral artery for 30 min with the following reperfusion for 48 hours, both markers were detected in cells of subventricular zone and in ependymocytes. These results indicate the changes in cytochemical patterns of the candidate stem cells.

Effects of immediate single transplantation of human umbilical cord blood mononuclear cells (UCB-MC) transfected with recombinant vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF2) genes into the area of injury were studied on the model of rat spinal cord dosed contusion at TVIII level. UCB-MC transfected with EGFP-N2 plasmid were transplanted into the rats of the control group under similar conditions. The presence of EGFP- labeled cells were traced in white matter during 21 days after transplantation at a distance no less than 10 mm in rostral and caudal directions from the nearest point of the injection. By 30 days after the transplantation of UCB-MC transfected with pBud-VEGF-FGF2 plasmid, the cross-sectional area of sparing grey matter increased by more than 60% at a distance of 3 mm from the epicenter of injury. By that time, in the animals of this group, the number of perivascular cells expressing beta receptor of platelet-derived growth factor (PDGFβR) was increased by an average of 30% in the outer zones of white matter 1.5 cm from the injury epicenter. Delivery of the therapeutic genes VEGF and FGF2 to the damaged region and their expression in cell carriers stimulates vascularization and post-traumatic spinal cord regeneration.

In this research that was performed on isolated neurons of mollusk Lymnaea stagnalis, using neuron enucleation, the cytoplast was obtained which was then fused with another neuron resulting in cybrid formation. The experiments performed have shown that the isolated neurons are able to fuse with each other, forming binuclear neurons; also, like all other cells, they could be enucleated with the formation of cyto- and karyoplasts and, after fusion, they can form cell body-cytoplast, cytoplasts-karyoplast, and other complexes. This is associated with the appearance of all doubtless indicators of fusion described for fusion of nerve cell bodies. This work demonstrates the possibility to artificially fuse the amputated neuroplasm fragment with neuronal cell body - the metabolic center of another cell. Theoretically, this means that in vivo amputated neuronal process also can be fused with a novel cell.

Using the methods of luminescent microscopy, the results of injection of autologous multipotent stromal (mesenchymal) stem cells of bone marrow origin (SSCBMO) containing GFP gene, into thrombosed hindlimb vein were studied in 226 male Wag rats. It was found that the restoration of blood flow through the thrombosed main vein was not always the result of thrombolysis. No signs of incorporation of injected SSCBMO into the wall of thrombosed vessel, clot recanalization or collateral formation were detected. In experimental thrombosis model with thrombin administration and main vein ligation, the thrombosis of its small branches also took place. The restoration of blood flow occured via either blood clot recanalization or obliteration of thrombosed vessels and the outgrowth of the new ones. SSCBMO were found to participate in both of these processes resulting in faster restoration of a blood flow in the tissue microregion of thrombosed vein. Gradually the injected SSCBMO and the structures formed with their participation, were replaced by the own cells of a recipient organism.

To assess the effects of weightlessness on the organism of mammals, splenic lymphoid tissue was studied in 10 intact Mongolian gerbils and in 10 animals after a 12-days-long spaceflight. In experimental animals the body mass and splenic, thymic and adrenal mass indexes were sharply reduced. In the spleen, the red pulp area was significantly increased, there appeared the areas of fibrous tissue proliferation, and extensive hemorrhage. Lymphoid nodules with germinal centers disappeared, while periarterial lymphoid sheaths were depleted. Quantitative analysis of cellular content of the lymphoid structures of the spleen showed dramatic activation of cell destruction, lymphocytopoiesis suppression with the disappearance of mitotically dividing cells and a decrease in the number of blast cells. The absence of plasma cells indicates the suppression of the processes of the immunocytopoiesis. The complex of changes noted suggests the decrease of immunological barrier of lymphoid tissue in the spleen and in the whole organism, in gerbils under the conditions of weightlessness in the spaceflight.

This investigation was aimed at the study of lipid-storing and lipid-synthesizing structures of human integument system. The study included the examination of the skin taken from 5 topographically different areas of the bodies of 30 individuals of both sexes (6 females and 24 males) aged 22-60 years. The sections were cut using the freezing microtome and stained for the demonstration of lipids with Sudan III and IV, Black B, Oil Red, and for the fluorescence microscopy - with the water solution of phosphine 3R and acetone solution of Nile red. It is demonstrated that the lipid-synthesizing structures of skin are: keratinocytes, sebaceous gland exocrinocytes, dermal and hypodermal adipocytes. Skin lipid-storing structures are represented by lipid- synthesizing structures and the spaces between the stratum corneum keratinocytes and by the superficial part of the lipid film, formed by sebum. The extent of lipid-storing and lipid-synthesizing structures depends on the skin topographic area and on the individual's gender. The results also show that fluorescence microscopy with different fluorochromes is superior to classical light optical microscopy, ensuring more precise determination of localization, cell outlines, dimensions and shape of skin lipid-storing and lipid-synthesizing structures.

During the survey of 215 indigenous inhabitants of Kursk region, the activity of chromosomal nucleolar organizing regions (NOR) was examined in peripheral blood lymphocytes by a visual semiquantitative method based on silver salt impregnation (Howell W. M., 1975), and the general anthropometric indexes were determined. Significant differences in anthropometric indexes were identified among the groups with high, medium and low values of 10Ag NOR. It was established that with the increase of 10Ag NOR value in men, body mass and body mass index, waist girth and hip girth, waist-to-hip ratio and width of shoulders increased, while in women there was an increase in body mass, height, body mass index, hip girth and length of the legs.