[Status of the osteoclast-activating system in cosmonauts after long-duration missions to the International Space Station].

The results of studying the system of osteoprotegerin/ receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) in 22 cosmonauts after long-duration (124 to 199 days) ISS missions are presented. Immediately on return to 1 g, changes were observed in OPG and RANKL serum levels and the ability to produce unstimulated and stimulated PGA of peripheral blood mononuclear cells in vitro. Individual variability of these changes was noticed.

[Immunological aspects of a piloted mission to Mars].

The paper deals with the results of the effects of 520-day isolation and confinement modeling some elements of a mission to Mars on the immune system. Longitudinal analyses revealed that the mechanisms of adaptive response of the human immune system to the conditions of extremely long isolation led to a change of the parameters, characterizing innate and adaptive immunity. Among them the most important are: changes in the signaling PRRs--TLR, manifested in the reduction of the percentage of circulating monocytes and granulocytes expressed on its own surfaces TLR2, TLR4 and TLR6, decreases early NK cell activation potential, increases in the percentage T- and B-lymphocytes, that expressed early activation marker CD69 after adequate stimulation, and in production of cytokines in response to PHA stimulation.

[Dynamics of changes in bone mineral density and structural organization in cosmonauts following space flight of 6 months in duration].

Microgravity effect on bone tissue of cosmonauts was evaluated following space flights of 6 months in duration. Peripheral quantitative computed tomography (pQCT) was used to determine volumetric bone mineral density (VBMD) and structure of distal parts of the leg and forearm. Changes in VBMD were found to correlate with bone position relative to the vector of gravity.