Membrane Lipids and Osmolytes Composition of Xerohalophilic Fungus Aspergillus penicillioides during Growth on High NaCl and Glycerol Media

Microbiology - Aspergillus penicillioides may be both xerophilic and halophilic. To study whether there is a difference in the mechanisms of adaptation to low water activity and high NaCl...     

Specific features of mental work capacity in 11-to 13-year-old schoolchildren during puberty

Experimental physiological, psychological, and hygienic studies were conducted for three years in the same fifth to seventh grade schoolchildren from 11 to 13 years of age. The findings made it possible to evaluate health status, the intensity of daily academic and out-of-school loads, changes in mental work capacity (MWC), and the relationship between the MWC and other indices of body function in the schoolchildren under study. The highest functional tension was experienced by the fifth grade schoolchildren and can be explained by the onset of puberty and changes in both the academic load and study conditions as compared to those at the previous stage of school education.     

Parameters of the innate and adaptive immunity in cosmonauts after long-term space flight on board the international space station

The results of the study of the innate and adaptive immunity indicators in 12 cosmonauts who took part in long-term (128–215 days) expeditions on board the International Space Station (ISS) are presented. It was shown that the space flight may lead to deviations in the human immune system. A decrease in the functional activity of phagocytes, NK and T-cells, as well as in the ability of immunocompetent cells to synthesize cytokines were observed. Significant individual changes were observed in the immune system’s response to a long-term space flight, which indicated an individual’s predisposition to the development of immune reactivity disorders under varying gravitation conditions.     

Expression, regulation, and pathophysiological role of NAD(P)H oxidases in atherogenesis

Oxidative stress has been implicated in the development and progression of atherosclerotic lesions. Significant increase of reactive oxygen species production by vascular cells can lead to progression of atherosclerotic lesions and development of unstable plaques due to triggering the apoptosis of endothelial and smooth muscle cells, expression of matrix metalloproteases and inflammatory cytokines. Cytolysis NAD(P)H-dependent oxidases appeared to be involved in reactive oxygen species production in the vascular network. Understanding of functions and regulation of individual NAD(P)H oxidases in atherosclerotic lesions can facilitate the development of novel therapeutic strategy for treating atherosclerosis. This review summarizes current data regarding expression, regulation and pathophysiological significance of these enzymes during development and progression of human atherosclerotic lesions.     

Cell interactions in microgravity: cytotoxic effects of natural killer cells in vitro

To study cell-to-cell interactions in microgravity we examined the functional activity of natural killer cells on board of the ISS. NK cells are the effector cells with direct cytotoxic activity to oncogenic, virus-infected cells and cells with modified differentiation. Ground-based experiments have shown that the examination of target cell lysis after incubation with NK cells is a simple and informative model for studying the influence of microgravity. NK cytotoxicity was measured as the value of non-degradeted labeled myeloblasts (K-562) after 24 hrs exposure with human lymphocytes in suspension. A special device was developed for space flight experiments. Human cultured lymphocytes and labeled K-562 cells were loaded into special syringes and delivered to the Russian segment of the ISS. Cosmonauts prepared co-cultured suspensions during the first day of microgravity, exposed them at 37 degrees C for 24 hrs and then separated H3-labeled cells on special filters. The results of ISS-8 mission showed that human NK cells in vitro remain lysis activity toward target cells in microgravity. The basal level of NK cytotoxicity was low and we did not found significant differences between "control" and "flight" values. Interferon production during the interaction between immune and target cells (ratio 10:1) in microgravity did not differ compared with ground-based control experiments. Ground exposure of the same lymphocyte samples with K-562 cells to 24 hrs clinorotation also did not lead to significant differences. These experiments paved the way for understanding the cell interaction mechanisms in space flight and the obtained results suggest that microgravity does not disrupt the interaction of NK cells with tumor cells.     

New species of stromatoporoidea from the Upper Ordovician and Silurian of the Subpolar Urals

Stromatoporoidea are widespread in the Upper Ordovician and Silurian beds of the Kozhim River (western slope of the Subpolar Urals). Five new species Cystostroma prodigiosum sp. nov., Stylostroma flabellatum sp. nov., Labechiina arguta sp. nov., Ecclimadictyon faveolatum sp. nov., and Araneosustroma astroplexum sp. nov. are described.     

The survival of micromycetes exposed to space conditions

Original data on the survival of fungal spores exposed to space conditions are presented. The experiment was carried out on the Earth-orbiting Russian satellite Foton-M4. The flight duration of the satellite was 45 days. Thirteen fungal species (hyaline as well as pigmented) from 10 genera recovered from destructed stone materials were studied. Sterile quartz sand was inoculated by the fungal spores and was placed into Eppendorf tubes. During the space flight, the Eppendorf tubes with fungal spores were kept inside the Foton descent capsule in the “Biokont” containers and on the external surface of the capsule in the “Exobiofrost” containers exposed to the open space as well. Spores of ten species (77% of all tested species), i.e. Acremonium charticola, Aspergillus niger, Aspergillus versicolor, Chaetomium globosum, Cladosporium sphaerospermum, Penicillium chrysogenum, Penicillium verrucosum, Purpureocillium lilacinum, Sarocladium kiliense, and Trichoderma harzianum, survived after the flight both inside and outside the descent capsule. Only three species (23% of all tested species), i.e. Acremonium furcatum, Engyodontium album and Verticillium zaregamsianum, failed to survive outside as well as inside the capsule. Spore viability differed depending on the fungal species. Thus, spores of some fungal species are able to survive under the complex of stress factors such as low temperature values, radiation, etc. We have shown that micromycetes can be used as a model group for study of eukaryotic organisms’ resistance to stress factors, due to their high tolerance not only to extreme terrestrial environments, but to the extraterrestrial ones as well.     

Adaptive immunity as an indicator of optimum physical loads during 520-day isolation

High stress level in the mechanisms responsible for adaptation to physical work affects the human immune system. Therefore, the effectiveness of countermeasures of reduced physical activity was studied using some parameters of the immune system. Our purpose was to examine how different types of exercises can modify physical performance and immune function in six subjects volunteered for Mars-500 simulation study. During the study, the resistance and cyclic training alternated over the period of about two months. According to the design, training was interrupted twice by an interval of approximately one month. The training plan was developed so that the initial and final stages of isolation could not impair the effectiveness of training. The cyclic training included running on the motorized and non-motorized treadmill and bicycling. Resistance exercises were performed using the MDS multifunctional exercise machine, expanders, and the Galileo 2000 vibration plate. Physical performance was assessed by the criteria of maximal voluntary effort, incremental locomotion, and bicycle exercise tests. Analysis of the quantitative and functional properties of effector cells of both innate and adaptive immunity was employed to investigate the immune status of subjects. Due to the plan of physical training, the level of physical performance in isolation was better than during the baseline data collection, although the intervals caused a considerable decrease in performance. Comparison of immunograms with the baseline ones showed positive changes: the number of naive CD4 ⁺Т-cells (CD4 ⁺ CD45RA ⁺) increased significantly. The functional activity of adaptive immunity did not reduce during isolation; on the contrary, the ability of T cells to express the early activation marker CD69 ⁺ on the surface was increased. The immune status parameters assessed in the subjects in the second half of the isolation period indicate that the proposed physical loads were adequate. In addition to retention of the baseline level of, or improvement in, physical performance, positive activation of the T component of adaptive immunity was observed.