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A T Lesniak

Publications and source records attributed to A T Lesniak.

10 recordsLinked to original sources
PubMed1999

[The diagnosis of disorders of the T-cell immunity component in space flight].

The investigation yielded two modifications of the procedure FOR determination of T-lymphocytes' functional activity in microsamples of the finger capillary blood and PHA-assisted cultivation of cells in syringe for subsequent morphological analysis by cosmonauts in flight. Testing of the proposed modifications in 14 healthy donors with unconstrained work/rest schedule, 4 volunteers in 60- and 6 volunteers in 120-day HDT showed a rather high comparability of data obtained with the modified and genuine procedures for determination of the T-lymphocytes proliferative activity in cosmonauts before and after orbital flights. Thus, the modified procedures can be successfully used for monitoring the immune status of cosmonauts on missions, and individuals exposed to extreme environments.

Cell Culture Techniques↗
PubMed1998

[Human cellular immunity and space flights].

Results of studying cellular immunity of crew members of long-term space missions, data of an experiment with extended head-down tilting of human subjects (HDT), and data obtained in the course of adapting immunologic test methods for the use in microgravity are summarized. Disorders in immunologic reactivity were shown to occur under the conditions of space flight. They included decreases in both quantitative and functional indices of cellular immunity, and emergence of signs of sensibilization to different allergens. The modified tests were evaluated by efficacy of determination of the proliferative activity of lymphocytes in minimal volumes of capillary blood inside one-piece syringes with a medium containing PHA and the Cytodex-1 suspension, evaluation of natural cytotoxicity on the level of an effector cell (number of peripheral blood lymphocytes capable of producing conjugates with fixed target cells). Sensibilization to allergens of normal human microflora was tested in analogs of routine hematocrit capillaries used for examination of healthy donors under ordinary rest-work regimen. No significant differences between the standard and modified tests were revealed. The proposed test modifications are quite simple in use and require minimum of equipment.

Adult↗
PubMed1997

[Immune resistance of humans during extended isolation].

Analyzed were parameters of the immune reactivity and allergological status of participants in the 135-day chamber experiment with periods of induced psychoemotional strain. Stressful situations gave rise to shifts in the antibody system, i.e. decreased blood levels of ImgA, ImgM, and ImgG, decline in the functional activity of T-lymphocytes, suppression of the cytokinetic activity of lymphocytes-natural killers, and sensibilization to various allergens. Totality of these shifts resembles the ones which are typically seen during initial readaptation to the Earth's conditions on after long-term space mission.

Humans↗
PubMed1989

Immunocompetent cells producing humoral mediators of bone tissue mineral metabolism during space flight simulation.

During 120-day and 370 day hypokinesia the possibility has been shown of manifestation of mechanism of immunological regulation of osteoclast functions. Supernatants of mononuclear peripheral blood cells which were in vitro nitrogen-stimulated, had an increased potential for resorption in 45Ca-labelled mice fetus long bone organ cultures. Resorbing activity was increased in mononuclear supernatants from some of the subjects exposed to 120-day hypokinesia and from all subjects exposed to 370-day hypokinesia. This variable returned to base-line values after completion of the bed-rest period. Lymphocyte in vitro proliferative activity decreased at the end of hypokinesia and during the initial days of recovery, and the number of active T-rosetting cells was, on the contrary increased. This suggested a possible activation of part of immunocompetent cell population potentially producing humoral regulators of bone cell functions in vivo. A study of a group of healthy males performing their routine daily activity and of patients with local osteoporosis (paradontitis) showed significant differences between normal subjects and patients, confirming the informative value of the method used and allowed to establish approximate limits of physiological variations of the values.

Adult↗
PubMed1979

[Antibodies to muscle fiber antigens in the cosmonauts after a space flight].

The study of serum samples, obtained from 15 cosmonauts before and after space flights, with the use of the indirect fluorescent method showed that in 7 cosmonauts antibodies to different elements of the human heart muscle appeared after flights. Strong and very strong luminescence of the elements of heart muscle tissue was detected in the cosmonauts after the third space flight. When studying the sera on sections of bovine heart muscle tissue, the reactions of the sera taken before and after flights were found to have no essential differences.

Animals↗
PubMedDate not supplied

[Immunologic mechanisms of regulating calcium metabolism in human bone tissue (production of osteoclast-activating factor) during long-term anti-orthostatic hypokinesia].

During 370 days 10 healthy male subjects were exposed to antiorthostatic hypokinesia. The exposure enhanced the production of the osteoclast-activating factor (OAF) by blood mononuclear cells. The enhancement began after the 2nd month of hypokinesia and continued to increase thereafter. The index of resorption was: prior to hypokinesia--1.15 +/- 0.156, 8 months after onset--2.05 +/- 0.129, and 11.5 months after onset--2.37 +/- 0.296, the upper normal limit being 1.54. The changes were correlated with a greater amount of active T-lymphocytes in blood and a progressive increase of calcium negative balance. This investigation lends support to the previously formulated hypothesis (I. V. Konstantinova, 1986) that immunological mechanisms associated with the OAF production contribute to calcium metabolism disorders in human bone during prolonged space flights.

Adult↗
PubMedDate not supplied

[Effect of space flight on cosmonaut peripheral blood lymphocyte blast transformation].

The postflight investigation of cell mediated immunity of seven cosmonauts showed significant increase in spontaneous activity of lymphocytes of peripheral blood and decrease in stimulation of lymphocytes cultured with PHA at R + O. Variations in these parameters were transient, remaining within physiological limits. Two cosmonauts displayed a stable increase in lymphocyte activity during blast transformation test with Staphylococcus aureus culture filtrate.

Humans↗