[Copper nanoparticles as modulators of apoptosis and structural changes in some organs].

The effect of repeated intramuscular injection into the organism of copper nanoparticles (CNP) with the diameter of 103 nm on the index of cell readiness to apoptosis and the structure of liver, spleen, kidney, as well as sensomotor cerebral cortex, was studied in 78 male Wistar rats. CNP were injected once per week for 12 weeks. The organs were studied using histological, immunohistochemical and morphometric methods. It was found that after the injections, CNP were distributed into organs and tissues of animals causing structural changes that were specific for eaach tissue. Toxicity of CNP in respect to microgliocytes was demonstrated at a dose of 2 mg/kg, hepatotoxicity and nephrotoxicity--at 6 mg/kg. The increase of CNP load on the organism up to toxic threshold (maximum tolerated dose) resulted in the appearance of signs of dystrophy and tissue necrosis. The data obtained suggest the application of an index of cell readiness to apoptosis, as assessed by caspase 3 expression, as a criterion for evaluation of CNP injection safety.

[Morphological peculiarities of the synovial membrane of human knee joint in mature age].

The structural and functional reorganization of the synovial membrane of the knee joint capsule was studied in 22 individuals of mature age (30-65 years) of both genders with the use of light and electron microscopy, histochemistry, immunohistochemistry and morphometry. The morpho-functional peculiarities of the synovial membrane remodeling in the II period of mature age included: increase the in the synovial intima thickness; significant accumulation of type IV collagen at the border of synovial intima with the subintimal fibrovascular layer of synovial membrane; activation of matrix metalloproteinases MMP-2 and MMP-9; increased cell proapoptotic activity in synovial intima. Collectively, these changes may initiate the disturbances in fluid production and the development of the degenerative-dystrophic processes in the articular cartilage at this stage of ontogenesis.

[Morpho-functional characteristics of the bronchiolar exocrinocytes (Clara cells) in adults].

Using the methods of immunocytochemistry, light, electron microscopy, and morphometry, localization and the structural and functional characteristics of bronchiolar exocrinocytes (Clara cells - CC) in human bronchiolar epithelium were studied during the mature age period of ontogenesis. CC were detected in both terminal and respiratory bronchioles, while their number was greater in the latter. With the increasing age within this period of human ontogenesis, the number of CC decreased. The quantitative decline of their number with age was found to depend on the duration of smoking. The smoking experience equivalent to 10 pack-years was defined as a critical one, as despite the absence of radiological manifestations of pulmonary pathology and the optimal results of the pulmonary function tests, in patients with this or greater smoking experience, the minimal fibrosis was detected, which could be demonstrated at both light and electron microscopical levels. This could be related with the decrease in CC number, since their secretory product was found to inhibit the activity of fibroblast chemotaxis.

[Structural-biochemical reorganization of rat liver caused by hydrogen sulfide-containing gas mixture]. / Strukturno-biokhimicheskaia reorganizatsiia pecheni krys pri vozdeistvii serovodorodsoderzhashchei gazovoi smesi.

Morphological equivalents of hepatocyte response to environmental factors of various intensity, associated with biochemical processes and directed at cell survival were studied in white outbred male rat using morphological (light and electron microscopy, histoautoradiography) and biochemical methods. As judged by the responses of intracellular structures, an exposure to hydrogen sulfide-containing gas, a pathogenic environmental factor, results in unequal changes in hepatocytes in different lobule zones. Small doses cause an activation of metabolic processes in hepatocytes that have plastic directivity. High doses of hydrogen sulfide-containing gas mixture result in the appearance of some signs of hepatocyte adaptation to extreme situation. Positive dynamics of structural modifications of the liver after the administration of nootropil and vitamin complex with antioxidant properties as correcting substances, indicates the reversibility of hepatocyte changes following long-term (up to two weeks) exposure to low doses and short-term exposure to high doses of hydrogen sulfide-containing gas mixture.

[Structural reorganization in the lining epithelium of airways and respiratory areas of the lungs following exposure to hydrogen sulfide-containing gas mixture]. / Strukturnaia reorganizatsiia pokrovnogo épiteliia vozdukhonosnykh i respiratornykh otdelov legkikh pri vozdeistvii serovodorodsoderzhashchei gazovoi smesi.

Structural reorganization of epithelium lining of pulmonary airways and respiratory portions was studied experimentally in outbred albino rats exposed to low doses (10 (g/m3) of hydrogen sulfide-containing gas mixture (natural gas + air) using the methods of histoautoradiography, electron microscopy and immunohistochemistry. Daily 1-hour-long exposure to gas mixture for up to 14 days resulted in moderate stimulating effect on specialized cells of bronchial epithelium. Following more protracted exposure to gas mixture (up to 1 month), the process demonstrated the involvement of protective mechanisms operating not only at the subcellular, but also at the tissue level, that was revealed by activation of DNA-synthesizing capacity of bronchial epithelial cells. Secretory Clara cells serving as the outpost of respiratory portion, were found to be significantly activated. The reversibility of the structural modifications in the pulmonary epithelia was demonstrated by the study of the organ 1 week following the discontinuation of a 1-month-long exposure to gas mixture.

[The structural-functional changes in the epithelium of the respiratory area of the nose and intrapulmonary bronchi in human ontogeny]. / Strukturno-funktsional'nye izmeneniia épiteliia dykhatel'noi oblasti nosa i vnutrilegochnykh bronkhov v ontogeneze cheloveka.

The epithelia of nasal respiratory area and intrapulmonary bronchi were studied in human ontogenesis by means of light and electron microscopy. The results indicate the stageness of morphofunctional organization of epithelia of the organs studied. The succession of the respiratory tract epithelium cytodifferentiation, dynamics of correlation between the epithelial layer cell elements in ontogenesis and peculiarities of ultrastructural organization of the nasal mucosa epithelial cell were established.