Vol 150, No 5 (2016)

PECAM-1/CD31 (biomarker of endothelial function and neovascularization) was used to assess protein expression in microvessels of cortical layers II, III and V in Mongolian gerbils ( Meriones unguiculatus ) in the early (Day 2) and late (Day 7) reperfusion period after a 7-minute forebrain ischemia and subsequent ischemic postconditioning (IPostC), as well as in sham-operated animals (n=60). The latter demonstrated the lowest level of immunoreactivity to PECAM-1/CD31 in the structures in cortical layer III. Reversible ischemic brain damage manifested itself in the reduction of number of morphologically unchanged neocortical neurons and extension of the reperfusion period; in addition to that, an increase in the level of immunoreactivity to PECAM-1/CD31 was observed in layers II, III and V of the cortex and it was significantly augmented towards the late reperfusion period. IPostC, performed by three stimulating cycles of ischemia-reperfusion lasting 15/15 seconds, resulted in a significant increase in the number of morphologically unchanged neurons in cortical layers II and III in the early reperfusion period. In the late reperfusion period, after IPostC, the number of unchanged neurons in layers II, III and V of the cortex was increased, while the level of immunoreactivity for PECAM-1/CD31 in these structures was significantly decreased. These results allow to conclude that the cytoprotective effect of IPostC under ischemia was implemented through the physiological mechanism of adaptation, which enhanced immunoreactivity for PECAM-1/CD31 in microvessels of the cerebral cortex in the early reperfusion period, and inhibited it in the late reperfusion period.

Morphometric properties of Clarke’s nuclei and their distribution in gray matter of the cat’s spinal cord were investigated using the methods of histochemical acetylcholinesterase demonstration, immunolabelling of non-phosphorylated domains of heavy neurofilament chains (SMI-32) and Klüver-Barrera technique for myelinated fiber demonstration. As a result of this research, averaged metric maps for LI-LIV lumbar segments of the spinal cord with Clarke’s nuclei boundaries were constructed based on the data received on 5 cats. The work provides information essential for precise stereotaxic access to Clarke’s nuclei in future fundamental and applied studies.

Segmentation of the vertebral venous bed and its interrelation with other venous vessels were investigated on 100 human corpses (including those of 25 embryos and fetuses of 4 weeks and older, 15 newborn infants and children and 60 adults aged up to 90 years) using anatomic and histological methods. Te vertebral venous bed was found to be a complicated formation of venous vessels, that was formed around the spinal cord during the ontogenesis. It was demonstrated that the venous bed of an individual vertebra contained five orders of intra- and extra-vertebral veins: intraosseous veins, veins of the vertebral canal, anastomotic veins, veins of the external vertebral plexus and veins of lateral longitudinal tracts. Venous segments of the individual vertebrae formed segments of higher order, and each of them is was connected with the veins of a certain body area, certain organs and certain venous tracts. Two forms of segmentation of the vertebral venous bed - metameric and longitudinal are described. Morphological criterion of segmentation is the genetic principle of metamerism which determines the areas of outflow of venous blood, the number of vessels, their diameter, presence of valves and relationship with surrounding connective tissue structures.

The articular cartilage was studied in 12 mongrel dogs 6 months and 1 year after gonarthrosis modeling followed by tunneling of the subchondral area and bone marrow suspension injection into the canals. The results of histological and morphometric study demonstrated that joints without tunneling developed progressing arthrosis; relative number of empty lacunae grew up, and that of isogenous chondrocyte groups diminished, while chondrocytes decreased in size and number and showed signs of destruction. The tunneled joints demonstrated decrease of degenerative changes in the articular cartilage manifested by the reduction in the number of empty lacunae and absence of foci of fiber separation in the matrix. The number of isogenous groups grew, as well as the volume density of chondrocytes, while the nuclear-cytoplasmic index decreased, which is indicative of the increase in proliferation and biosynthetic

127 children aged 7-11 years were examined, 42 of them with diagnosed mental retardation of moderate severity level (F 71 in accordance with ICD-10), including 15 children that were brought up by their families and 27 were kept in a specialized residential care home for mentally retarded children (without parental care).The control group consisted of 85 schoolchildren of the same age. Anthropometric parameters were measured to determine somatotype and harmony of physical development. It was found that mentally retarded children brought up in families didn’t differ from healthy children by the main anthropometric parameters. Children of this group had a slight tendency to be overweight and belong to macro- and micro- somatotypes. Children kept in specialized care homes were smaller than their age mates in other experimental groups, belonged mostly to microsomatotype and tended to have body mass deficit. The results prove that while examining physical health of mentally retarded children, it is necessary to take into account social factors such as presence or absence of parental care.

The study was carried out on frontal sections of the Wistar rat brain (n=5) with the use of immunocytochemical methods. For the first time beta-catenin was found in the nuclei of mature neurons of the medial part of habenula. Since intranuclear localization of this protein indicates its involvement in the canonical Wnt signaling pathway, which is normally realized in embryogenesis, it is suggested that habenular neurons retain the properties that are not characteristic of mature neurons.

The aim of the work was to study the structural changes of A pancreatic islet cells of the in dogs with impaired glucose tolerance after a single moderate or regular physical activity. The experiments were performed on 28 adult male dogs aged 2-4 years, 10 of them served as the control group. Pancreatic islet A cell structure was examined using histological, electron microscopic and morphometric methods. Results of the study to demonstrated variations in the localization of A cells in the pancreatic islets of dogs depending on the state of body carbohydrate metabolism. More pronounced structural changes developed in A cells after a training cycle. Along with the compensatory-adaptive response, the cells developed changes indicating their functional stress (reduction of the relative volume of cells and of secretory granules, «empty spaces» in the cytoplasm, hypertrophied Golgi complex) and the depletion of energy reserves (rarification of mitochondrial matrix and cristae destruction).

On the basis of literature data and the authors’ original research, morphologic characteristics of mechanisms that determine mechanical properties of bone structures at nanolevel are summarized, and future perspectives and methods of research are formulated. It is shown that one of the mechanisms defining mechanical properties of the skeleton is represented by the bonds formed between organic matrix components that are mediated by bivalent ions. A hypothesis is formulated that bonds between minerals through their hydrate layer play the main role in the establishment of hierarchical mineral matrix organization and its properties. Probing bone structures by x-ray spectral methods like XANES spectroscopy was suggested as a perspective technology for investigating local electron and atomic structure of hydrate layer and its participation in the functioning of nanolevel mechanisms defining mechanical and physico-chemical bone tissue properties. It is suggested that such morphological investigation with the use of calculated simulation could be helpful in getting a more complete knowledge of mechanical characteristics and properties of bone matrix mineral component.