Vol 139, No 2 (2011)

This paper presents the systematized summary of current literature data and the authors' own findings on the regularities of human and animal surface oral mucosal epithelium (OME) injury caused by cytostatic drugs (CSD) administration, and on the ways of its regeneration after the cytostatic chemotherapy (CSCT) discontinuation. Tissue, cell and molecular mechanisms of CSCT effects on OME, are described. The direct effects of CSD included the epithelial layer attenuation with the derangement of its architecture, epitheliocyte proliferation suppression, apoptosis activation, and differentiation disturbances (involving the broad spectrum of cytological, cytochemical, ultrastructural and molecular-biological changes). In severe cases, these processes resulted in the loss of the epithelial layer integrity with the development of ulceration. Complete epithelial regeneration requires a long period after the CSCT discontinuation. Indirect effects of CSD on OME are associated with the microbial invasion and the diffusion of microbial vital activity products into the epithelium with concurrent leukopenia, immunosuppression and decreased salivary secretion.

The purpose of this study was to investigate the expression of intermediate filament proteins (vimentin and glial fibrillary acidic protein - GFAP) in the cells of embryonic rat neocortex at different time points after its allotransplantation into injured sciatic nerve of adult animals. Using immunohistochemical methods, the differentiation of GFAP-positive astrocytes from vimentin-positive radial glial cells was observed in embryonic rat neocortex, grafted into sciatic nerve. It was shown that the differentiation of the embryonic neocortical astrocytes in the transplants took place a few days earlier than in the rat neocortex during normal ontogenesis. Reactive gliosis was demonstrated in the long-term transplants, as indicated by a large number of intensely stained GFAP-positive cells and vimentin-containing astrocytes. These findings suggest that ectopic neurotarnsplants could serve as a model for fundamental studies of the mechanisms of reactive gliosis development.

The investigation was performed on the isolated living neurons of a mollusk (Lymnaea stagnalis). The purpose of this study was to examine the contractile activity of the injured neuronal processes. Retraction of latter in Ringer's solution was found in 90% of the cases. The specific club-shaped structure (retraction bulb) served as a marker of contraction. The speed of process contraction fluctuated in different neurons from 0.03 to 9 μm/ min. As a result of usual linear contraction, the process diameter was increased on the average by 35%, while the cell body volume was increased on the average by 30%. The three forms of contractile activity were distinguished: linear contraction, isometric contraction (reduction of a process thickness with no change in its length) and mixed form of contraction. It is suggested that the mechanism of retraction takes part in the formation of diastasis after nerve sectioning and injury of the brain conducting pathways. Diastasis in the nerve is formed not only due to the elastic properties of its fibrous sheath and glia, but also as a result of nerve fiber retraction.

This investigation was aimed at the analysis of the shape and morpho-densitometric parameters of the erythrocytes in rats with experimental hypervitaminosis A. Male Wistar rats received 0.64 mg/g (1167 IU/g) of retinol palmitate (RP) in oil solution orally for 11 consecutive days. Rats fed oil alone and intact animals were used as control groups. At days 5 and 6 of the experiment, the first manifestations of hypervitaminosis A were observed (body mass loss, localized erythema and hemorrhages). In contrast to control groups, in rats with hypervitaminosis A, the area of erythrocyte cytoplasm decreased gradually in response to RP administration. Discocyte/spherocyte/stomatocyte ratio also changed dynamically: the proportion of discocytes progressively decreased, while the amount of spherocytes and stomatocytes increased. These results show that excess of the vitamin A alters the erythrocyte membrane structure. Integral optical density of erythrocyte cytoplasm in RP-treated rats as well as in oil-fed rats was lower than in intact animals. This may be an indirect evidence of the fall in erythrocyte hemoglobin content. The changes observed in erythrocytes of RP-treated rats may serve as an additional criterion for evaluation of hypervitaminosis A severity.

Methods of light, electron microscopy and immunohistochemistry were used to study the samples of maxillary sinus (MS) mucous membrane (MM) under normal conditions and in odontogenic sinusitis. To study the normal structure, the samples were obtained at autopsy from 26 human corpses 12-24 hours after death. Electron microscopic and immunohistochemical study was performed on biopsies of grossly morphologically unchanged MS MM, obtained during the operations for retention cysts in 6 patients. MS MM in perforative sinusitis was studied using the biopsies obtained from 43 patients. The material is broken into 4 groups depending on perforative sinusitis duration. Under normal conditions, MS MM is lined with a pseudostratified columnar ciliated epithelium. Degenerative changes of ciliated epithelial cells were already detected at short time intervals after MS perforations and become apparent due to reduction of specific volume of mitochondria and, rough endoplasmic reticulum, and increase of nuclear-cytoplasmic ratio. In the globlet cells, the reduction of nuclear-cytoplasmic ratio was associated with the disturbance of the secretory product release. At time intervals exceeding 3 months, epithelium underwent metaplasia into simple cuboidal and stratified squamous keratinized, while in MS MM lamina propria, cellular infiltration was increased. CD4+ cell content in sinus MM gradually increased, while at late periods after perforation occurrence it decreased. Low CD4+ cell count within the epithelium and the absence of muromidase on the surface of MS MM was detected. With the increase of the time interval since MS perforation, the number of CD8+ and CD20+cells in MS MM was found to increase.

Using the methods of luminescent microscopy and cytospectrofluorometry, biogenic amine-containing structures were studied in colon of rats subjected to alcohol intoxication of 2, 4 and 6 months' duration. It was demonstrated that 2- and 4-monthlong alcohol intoxication of animals resulted in biogenic amine content increase in the mucosal surface epithelium, submucosal mast cells and adrenergic nerve fibers within the connective tissue bands in the muscular tunic. At the same time, 6 month-long intoxication was accompanied by a stabilization of bioamine content at the elevated level.

140 preparations of the skull base and 97 preparations of the skull sagittal saw cuts were used to study the craniometric characteristics of the basilar part of the occipital bone. The dependence of craniometric characteristics on sex and form of the cerebral cranium was tested. Correlations between these parameters were determined. It was found that the occipital bone parameters studied have no significant sex differences, however the correlation was found between the width parameters of basilar part of occipital bone at the outer and inner cranial base. The data obtained should be taken into consideration during planning and fulfilling the transclival surgical procedures.

The aim of the study was to examine the distribution of cells expressing Msi-1 (Musashi-1) protein which is believed to be a marker of neural stem cells, in rat telencephalon. These cells were found to be concentrated in the subventricular proliferative zone and diffusely scattered in striatum and hippocampus. Moreover, neurons with extensive Msi-1 reaction were found in habenular nuclei. The data obtained are not in full agreement with current views on the localization of neural stem cells in the brain.