Vol 139, No 3 (2011)

In the preceding work («Morphology», 2011, issue 2), the regularities of oral mucosal (OM) epithelium injury after the cytostatic drug (CSD) treatment and its further regeneration, were reviewed. This paper presents the systematized summary of current literature data and the authors' own findings on the regularities of CSD effect on non-epithelial OM cell populations and their interactions with each other and the epithelium. The changes of intraepithelial tissue homeostasis, associated with CSD effect on intraepithelial lymphocytes, granulocytes, dendritic antigen presenting cells and melanocytes, interacting with epitheliocytes, are described. The data are presented, indicating that along with the epithelium, the cell populations of lamina propria and submucosal connective tissue, as well as the small blood vessels, are important targets of CSD in the OM tissues. The concept of a unifying model, describing tissue, cellular and molecular mechanisms of the oral mucositis development after CSD treatment, is reviewed.

Glutamate receptors in the central nervous system play a significant role in the mechanisms of differential adaptation to the environmental conditions. However, structural and functional parameters of kainate receptors (KR) under normal conditions and during exposure to stress are not well characterized. Therefore, the aim of this research was to 1) study the distribution and the quantity of KR GluR 5/6/7 subunits; 2) examine their changes in the pyramidal cell layer of the hippocampus in rat strains with have genetically determined distinctions in the levels of nervous system excitability following the exposure to short-term emotional-painful stress; 3) estimate the sensitivity of hippocampal pyramidal neurons to the action of KR agonist - kainic acid. It was demonstrated that GluR 5/6/7 KR are localized mainly in the region of hippocampal CA2 area; in the animals with low excitability their quantity was greater than in those with high excitability. Short-term emotional-painful stress resulted in the increase of KR in hippocampal CA2 area only in highly excitable rats. Selective sensitivity of pyramidal neurons in different hippocampal fields to the action of kainic acid was demonstrated and it was found to depend on animal strain characteristics of of the nervous system excitability.

Using the Ilizarov apparatus, the shin of 9 adult mongrel dogs was lengthened. Morpho-functional state of the neurons in LVII spinal nerve sensory ganglia that are involved in tibial innervation, were studied using neurohistological and quantitative methods after the distraction that was performed during 28 days with the rate of 1 mm (4 fractions) a day, followed by one monthlong fixation and one month after apparatus removal. Material, obtained 3 intact dogs was used as a control. The most intensive development of structural changes in different populations of sensory neurons was detected during the period of distraction; they persisted for one month after apparatus removal. As compared with the intact animals, in the populations of large, medium and small neurons, a 2-3 fold reduction was found in the number of normochromal cells with the central location of the nucleus and nucleolus in the center, with the concomitant proportional increase of the number of cells with the combined peripheral chromatolisis and dislocation of nuclear-nucleolar apparatus.

Using the inverted phase contrast microscope, the supravital study of structural dynamics of single myelin sheath gaps (nodes of Ranvier) of isolated frog myelin nerve fibers was performed after mechanical injury and in the medium with the decreased ion force under the conditions which induce, in electrophysiological experiments, the expression of the axolemmal K+-channels in the paranodal area. Videorecording has shown that within this area the myelin sheath stratification appeared that was associated with the swelling of Schwann cell cytoplasm enclosed in the terminal membranous loops of myelin. An increase of the degree of stratification of the lamellar myelin complexes make them invisible in the light microscope; therefore, it is not the translocation of the myelin sheath from the node cleft that is recorded, as many authors believed, but a shift of only the visible border of the compact, yet unstratified myelin sheath. Hence, the removal of myelin (demyelination) was absent, and the electrophysiological effect can be accounted for by a significant fall of electrical resistance in paranodal area as a result of swelling of terminal loops and stratification of the myelin sheath. Preparations examination also revealed a decrease of the axonal diameter in, which is proportional to swelling of the myelin sheath terminal parts. Since the outer fiber diameter did not change, it can be concluded that the process observed is the result of swelling of the Schwann cell cytoplasm due to the axoplasm water fraction which may be a peculiar process of axo-glial interactions.

The aim of study was to determine the probable sources of circulating endothelial cells (CECs) and establish the role of both VE-cadherin and vascular endothelial growth factor (VEGF) in molecular mechanism of endothelium desquamation using the hemorrhagic fever with renal syndrome as the model of endothelium injury. Autopsy pieces of kidney, liver, lung, brain, stomach and myocardium taken from 10 patients were studied histologically. Quantitative measurement of CECs was performed by the method developed by J. Hladovec (1978). Blood levels of VE-cadherin and VEGF were determined by ELISA method. Predominant sources CECs were found to be macro- and microvessels of kidney, liver, lung, brain, gastric mucous membrane, myocardium and, possibly - brain vessels. One of the molecular mechanism of endothelium desquamation is VEGF-stimulated internalization of VE-cadherin.

Using morphometric and immunocytochemical methods, the distribution of melanin-containing cells in the hair follicles was studied using the autopsy samples of the skin obtained from the temporal region of scalp of 74 male individuals of different age only in the epithelial hair matrix - both in sections stained with hematoxylin-eosin and in sections treated with the monoclonal antibodies against tyrosinase. The examination of unstained sections demonstrated that after 15 years the reduction of a total area occupied by melanin granules in the cytoplasm of melanocytes and keratinocytes took place. After 26 years the irregular but stable decrease was found in the number of pigment-forming cells. The number of melanocytes identified using the monoclonal antibodies against tyrosinase, was greater then the number of pigment cell detected by routine methods.

Subventricular proliferative zone is the brain area most intriguing and least understood in terms of cellular and spatial organization. The objective of this study was to focus on the structural and cytochemical organization of astrocytes of the subventricular zone of the rat brain. Astrocytes were detected immunocytochemically. The preparations were analyzed using conventional light microscopy and confocal laser microscopy. The study performed showed that the major cellular population of the subventricular zone was represented by a special kind of atypical fibrous astrocytes with the intermediate filaments containing only glial fibrillary acidic protein (GFAP). The processes of these cells formed a complex double-layer network beneath the ependyma. The described structural pattern of the glial skeleton of the subventricular zone seems to be determined by specific functions of the area and its location in the zone of CSF-brain barrier.

The formation of a competent doctor must be based on teaching standards for each discipline, the development of which is possible only as a result of provision of a real interdepartmental integration. The fundamental subjects must be taught not on the assumption of narrow professional interests, but in accordance with the requirements and demands of the clinical disciplines. The fulfillment of this task requires the development of a single computer base Standards of Medical Education and elaboration of the interdisciplinary modules. These must be based on the analysis of the demand of clinical Departments for new information blocks, the distribution of these blocks into different parts of the syllabus, their filling with the appropriate content, development of the adequate forms and methods of teaching.