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Biomedical subjects

M R Sapin

Publications and source records attributed to M R Sapin.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Response of immune system and lymphoid tissue of respiratory and gastrointestinal organs to space flight factors].

The studies demonstrated that gamma-radiation drastically enhanced destructive processes and suppressed the mitotic activity of lymphocytes in the thymus and spleen. This resulted in the altered morphological picture of immune organs: the inversion of layers occurred in the thymus, the splenic white pulp increased by three times, lymphoid nodules with germinating centers disappeared, the marginal area became thinner. Following gamma-radiation, restorative processes in the thymus and spleen were noticeable just on day 3 and 7, respectively. However, the cell composition of murine immune organs failed to achieve control values by day 60 after exposure. Examining the responses of respiratory and digestive lymphoid tissue to acetaldehyde and drinking water organisms indicated that as the concentration of an acting agent and the time of exposure increased, there was lymphocytopoietic inhibition in the lymphoid formations whereas its small doses activated a local immune response.

Animals↗
PubMed1998

[Lymphoid tissue in the wall of adult human gallbladder].

Lymphoid structures of mucosa and muscular coat from the gall bladder cervix, body and fornix were examined in histological preparations using morphometry and methods of variation statistics. Lymphocyte concentration in the organ walls grows proportionally to age. In the first period of maturity lymphoid nodules are absent in mucosal lamina propria while lymphoid nodules are rarely encountered among the cells of the fibroblastic series. Connective tissue layers of muscular coat are predominant sites of lymphoid aggregations. Senescence is characterised by the appearance of lymphoid nodules in the gall bladder mucosa. Cell concentration, structure and composition per unit area depend on nodule localization and the age of the individual.

Adult↗
PubMed1998

[Lymphoid tissue of mice spleen in the delayed periods following a single gamma-irradiation].

Morphofunctional state and recombination of cell composition of the spleen structural components were studied in mice Balb/c at delayed (post-irradiation days 21, 30, and 58) periods following a single gamma-irradiation by 6.9 Gy. At none of these time points did the lymphoid structural components of the spleen complete their morphological and cytological recovery. Morphological disturbances included poor development of germinative centers and marginal zones in lymphadens and periarterial lymphoid heads (PALH). Recovery of lymphoid cell population did not go on same pattern. Thus, by day 58 of recovery, in PALH small lymphocytes regained basal level but rose concentration to 79% in the lymphadens without germinative centers and to 60% in the lymphoden mantle and red pulp. Elevation of mitotic and cell differentiation activities was not equal. Destructive processes approached normal values in PALH and red pulp and remained by 85% beyond basal values in lymphodens. Mature/immature plasmatic cells ratio was modified. Moreover, plasmocytes (mature cells) that are responsible for humoral immunity, localized in unordinary sites, i.e. in PALH and lymphodens without germinative centers. Adaptive changes observed in the red pulp at delayed time-points after irradiation were manifested by development of myelopoiesis focuses with high concentrations of young forms of neutrophils and megakaryocytes.

Animals↗
PubMed1998

[Reaction of different cell populations in mouse thymus to a single gamma-irradiation].

Cytoarchitectonics of the functional zones of thymus was studied with the morphometric technique. Reactions of different cell populations to a single gamma-irradiation at a dose of 6.9 Gy were demonstrated. Acute reaction in thymus showed up already on the first day following exposure. Reparation began three days later and proceeded in two stages one of which (day 7) was accomplished by survived cells and the other (day 21), owing to the influx of precursors from recovered bone marrow. It was found that thymic substantia medullaris was less compromised by radiation as compared with cortex. This was due to the presence of more resistant lymphoid cells and activation of lymphocytopoiesis proper. It was also established that in the post-irradiation period (days 1 through to 58) cytoarchitectonics of the thymic functional zones has failed to complete recovery. Moreover, a second thymus depletion was observed on day 58.

Animals↗
PubMed1998

[Splenic lymphoid tissue of mice after irradiation with fast carbon ions].

Reorganization of cellular content of splenic functional zones was studied morphometrically in mice after single irradiation with fast carbon ions. It was demonstrated that irradiation does not cause significant changes in microtopography of splenic structures but is accompanied with changes in cytoarchitecture and rearrangement of lymphoid cells throughout the experiment. Two arbitrary stages are determined in lymphoid tissue response. The first one (30 hrs-7 d) is characterized with destructive processes intensification and decrease of small lymphocytes number in all functional zones of the organ. Strong plasmocellular reaction was observed in the organ except for the lymphoid nodules mantle zone in this period as well. On the second stage (15-60 d) orientation of plasmocellular reaction changes along with the tendency of small lymphocytes to restore population (up to 57-79% from the control level on d 60 of the experiment. As a result plasma cell content decreases sharply in all the organ structures. Low level of lymphocytopoiesis was demonstrated in the course of the experiment resulting from cell mitotic activity decline following the irradiation. At the distant period (d 60 following the irradiation) another decrease of cell lymphoid population was noted, which indicates that irradiation with fast carbon ions is suppressive to the animal immune system.

Animals↗
PubMed1997

Immune organs and haemopoietic system under modelling of the mission factors.

Literary and experimental data on the character of changes in immune organs and lymphoid tissue of respiratory system and digestive system in laboratory animals during the mission factors model area given. Inhibition of reproductive function in bone marrow, thymus and spleen under irradiation of gamma-rays and accelerated carbon ions, tensity of immune response in the lymphoid structures of larynx, trachea and bronchi under the influence of acetaldehyde vapors and decrease of lymphoid tissue square on histological series in spleen and small intestine with an increase of concentration of microbial bodies in the drinking water were estimated.

Acetaldehyde↗
PubMed1997

[Cytologic profile of mouse thymus and spleen after gamma-irradiation].

Quantitative study of thymus and spleen cytoarchitectonics performed in mice one day after gamma irradiation revealed peculiarities of response of certain morphological zones of the organs along with common changes of the organ cellular composition (lymphocytopenia, destructive processes intensification, granulocyte reaction and decrease of mitotic activity). In thymus changes of cytoarchitectonics of cortical substance (especially in subcapsular zone) are connected with sharp intensification of cell destruction, which implicates lymphocyte loss and with complete suppression of cell mitotic activity and differentiation, with medullar substance of thymus being the most stable structure in cellular composition. Lymphoid nodules without germinal centres, cytoarchitectonics of which, despite certain changes to greater extent resembles control indexes, can be considered the most stable structure in spleen, where irradiation completely suppresses germinal centres of lymphoid nodules. Red pulp appeares to be more labile zone in the organ and its architectonics is mostly subjected to alteration in irradiation.

Animals↗
PubMed1994

[Regularities of differentiation of lymphoid structures in the walls of hollow internal organs of man].

The regularities of the structure of lymphoid tissue in the hollow visceral walls were found while analyzing the results of studies conducted in the author's laboratory by examining a lot of materials--corpses of the individuals who had at their death had no inflammatory or other diseases which could greatly affect the structure of immune organs. In the walls of digestive, respiratory, and urinary organs, the author followed up the development of lymphoid structures from the lymphoid cells diffusely scattered in the mucosa to the accumulation of these cells and formation of lymphoid nodules with and without reproduction centers. He also analyzed the causes promoting the concentration of lymphoid cells as aggregates, the formation of lymphoid nodules in the viscera having their different structure and uses.

Adult↗