Bone loss recovery in mice following microgravity with concurrent bone-compartment-specific osteocyte characteristics.

Space missions provide the opportunity to investigate the influence of gravity on the dynamic remodelling processes in bone. Mice were examined following space flight and subsequent recovery to determine the effects on bone compartment-specific microstructure and composition. The resulting bone loss following microgravity recovered only in trabecular bone, while in cortical bone the tissue mineral density was restored after only one week on Earth. Detection of TRAP-positive bone surface cells in the trabecular compartment indicated increased resorption following space flight. In cortical bone, a persistent reduced viability of osteocytes suggested an impaired sensitivity to mechanical stresses. A compartment-dependent structural recovery from microgravity-induced bone loss was shown, with a direct osteocytic contribution to persistent low bone volume in the cortical region even after a recovery period. Trabecular recovery was not accompanied by changes in osteocyte characteristics. These post-space-flight findings will contribute to the understanding of compositional changes that compromise bone quality caused by unloading, immobilisation, or disuse.

Combined histochemical approach in assessing tryptase expression in the mast cell population.

To increase the efficiency of interpretation of mast cell's contribution to the state of a specific tissue microenvironment, it is necessary to detail the molecular composition of their secretome and analyze the pathways of degranulation. Developed method of combining immunomorphological and histochemical staining protocols contributes to the most objective detection of the integral level of tryptase expression in the intraorgan population of the skin mast cells. Novel technique for tryptase detection expands the possibilities of morphological analysis, provides researchers with additional data on the structure of the mast cell population and helps visualize the processing and cytological features and structural targets of tryptase during the development of adaptive and pathological reactions. Objective determination of the tryptase profile for organ-specific mast cell populations is in great demand in clinical practice for the interpretation of pathological processes, including inflammation and oncogenesis.

[Evaluation of the effect of remaxol on hepatocytes in non-alcoholic fatty liver dystrophy modeling in laboratory C57BL/6 mice]. / Otsenka vliianiia remaksola na gepatotsity pri modelirovanii nealkogol'noi zhirovoi distrofii u laboratornykh myshei linii C57BL/6.

OBJECTIVE: To provide a morphological evaluation of the effectiveness of incorporating remaxol into a treatment regimen for non-alcoholic fatty liver disease. MATERIAL AND METHODS: The investigation was conducted using 32 male C57BL/6 mice weighing 35-44 g, which were divided into 4 groups. In Group 1, eight mice were fed with a standard diet for 75 days; the animals from Groups 2 and 3 received a hypercaloric diet for the same period of time. The mice from Group 2 were euthanized immediately after the diet was stopped; and Group 3 was switched to the standard diet after 20 days of the recovery period. Group 4 included the mice that were, after a 75-day hypercaloric diet, were injected with remaxol at a dose of 25 ml/kg once daily every other day; the cycle consisted of 10 injections. Liver tissues were morphologically evaluated using Oil Red O-stained tissue specimens additionally stained with Mayer's hematoxylin on the cryostat sections applying a Zeiss Axio Imager. A2 microscope equipped with an Axiocam 506 color camera. The photographed images were processed using the ZEN 2.3 program ('Carl Zeiss', Germany). RESULTS: The morphological equivalent of liver improvement in mice that were injected and were not injected with remaxol was found to be normalization of the lobular structure, preservation of the structure and intralobular orientation of the hepatic tubules, and restoration of the width of the sinusoidal lumen. The degree of infiltration was much lesser than that in the group of experimental animals that did not additionally receive the drug. CONCLUSION: These histological signs may suggest that remaxol is effective in treating non-alcoholic fatty liver disease.

[Extracellular matrix collagen fiber structures of the gastrointestinal connective tissues in mice after a 30 day orbital flight].

The organs of the digestive system experience high sensitivity to the orbital flight factors and may limit the implementation of the professional activities of crews on International space station. The connective tissue as a system-forming matrix of the integrative and buffering metabolic environment has a particular importance in the space biomedicine because it provides the inner organ functionality in the conditions of changing level of the gravitational incentive. Aim - to study the adaptive mechanisms of the fibrous component of the extracellular matrix of the connective tissue of stomach and intestines on the effect of prolonged microgravity. MATERIAL AND METHODS: Using histochemical methods the condition of collagen fibers of a specific tissue microenvironment of the membranes of stomach and intestines of C57BL/6N mice (58 males with an initial body weight of 27.1±0.7 g) after a 30-day space flight and the following 7-day land readaptation was studied as well as in the animals representing corresponding control groups. RESULTS AND DISCUSSION: Laboratory animal presence on the biosatellite «BION-M¼ No. 1 has led to the fibrous reduction of extracellular matrix of connective tissue in the studied organs of digestive system structure except for the proper lamina of the gastric mucous membrane. Fibrillogenesis increase in the gastrointestinal tract in comparison with the indicators of space flight animal group has been found after 7 days of the biosatellite landing. The collagen fibers were not characterized by the significance change from the vivarium control group during the experiment with the land modelling of orbital flight conditions. CONCLUSION: The obtained results represent the evidence of fibrous structure gravity sensitivity of extracellular matrix of the connective tissue and show the relevance in the sphere of preventive measure improvement of the digestive system organs in the profession of astronauts in the orbital flight conditions.

[Tissue-specific reaction of the mucous coat of herbals' small gut under the influence of spaceflight factors on board biosat "Foton M3"].

Methods of light-optical microscopy, morpho- and cytometry and histochemisty were used to study the epithelial lining of herbal's small gut after 12-day flight in biosat "Foton M3". Changes in mucous coat histoarchitectonics included branching of villi and cystic lumps lined with prismatic epithelium. Shortening of the mucous membrane villi was accompanied by reduction of prismatic epithelium height, increase in the number of goblet cells and change of their dislocation, stimulation of excretion of biosynthesis products on the brush border surface pointing to impairment of the interstitial barrier function. Nothing evidenced change in mitotic index of the crypts epithelium in animals of the vivarium control, in the Kontur facility simulating the flight condition, and in the space flown herbals. There was a minor individual variability of changes in the epithelium mucous membrane due to the simulated flight factors.

[Morphofunctional state of hepatocytes nuclear apparatus in Mongolian herbils after the flight on space apparatus Foton-M3].

Morphofunctional state of hepatocytes nuclear apparatus was analyzed in the liver of Mongolian gerbils Meriones unguiculatus returned from 12-d space flight of Foton-M3 (SF) and their vivarium and ground synchronous controls. Volume, ploidy and number of hepatocyte nuclei, nucleolus dimensions and number as well as contacts with karyolemma were determined in the central, intermediate and peripheral areas of the liver classical lobe. Also, total number of mitoses and amitoses was determined in the liver parenchyma. The vivarium control animals displayed specifics of the nucleus apparatus structure that depended on intralobe topography. Based on the selected criteria, high functional activity was characteristic of cells in the intermediate area. According to the criteria, nuclear apparatus in the synchronous control tended to down the functional activity The adaptive adjustment of nuclei in SF seemed to have been initiated by changes in the hepatic blood flow: volumes of hepatocyte nuclei and nucleoli increased as did the number of nuclei in cell, whereas ploidy made a decrease, especially in the intermediate area. Under the SF conditions, particularly important compensatory mechanism for the liver function was intensification of amitosis and consequent increase of the population of dinuclear hepatocytes.

[Glycogen content in gerbil's liver following the spacecraft Foton-M3 mission].

Glycogen cytochemistry and distribution in hepatocytes of the classic liver lobules were studied in three groups of gerbils Meriones unguiculatus: vivarium, synchronous control and flown in the 12-d Foton-M3 mission. The control animals were shown to have the central glycogen distribution with a large pool of polysaccharides found in hepatocytes of the pericentral and intermediate lobules and a small pool in the periportal area. Glycogen in hepatocyte plasm was within the physiological norm in the alpha- and beta-granules, typically localized on the cell periphery. Exposure to the spaceflight conditions decreased significantly glycogen concentrations in each functional region of the hepatic lobules and reduced the gradient of polysaccharide distribution from the portal triads toward the central vein. In parallel, high glycogen heterogeneity formed in adjacent hepatocytes and loci. The presence of glycosomes evidenced disturbance of carbohydrates metabolism. In addition, intracellular topography of glycogen granules in cytoplasm was altered. Trends of glycogen in gerbils of the synchronous control were similar to the space flown animals but much less pronounced.

[Morpho-functional status of the thyroid gland and large cell hypothalamus nuclei in the ionizing irradiation and ethanol]. / Morfofunktsional'noe sostoianie shchitovidnoi zhelezy i krupnokletochnykh iader gipotalamusa pri vozdeistvii ioniziruiushchego izlucheniia i étanola.

Morphofunctional state of the thyroid and nuclei in the hypothalamic large cells was examined following exposure to ionizing radiation at the dose of 20 Gy without and with ethanol administration (2.25 g/kg) before or after exposure. The highest thyroid radioprotecting effect of the ethyl alcohol was achieved when introduced before exposure as it reduced apoptosis of thyrocytes and balanced the disturbances in colloid amino acids iodination. As for nuclei of the hypothalamic large cells, the radiomodifying effect of ethanol was synergic when introduced before and potential amplifying after the radiation exposure being manifested by distinct activation and ensuing overstrain and exhaustion of the neurosecretory cells. Analysis of the experimental data suggests causality of the thyroid protecting effect of ethanol by functional hyperactivation of supraoptic and paraventricular nuclei in the hypothalamus.