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Research Containing: Human Research

Pulmonary gas exchange is not impaired 24 h after extravehicular activity

by on 9 June 2015in Biology & Biotechnology No comment

Extravehicular activity (EVA) during spaceflight involves a significant decompression stress. Previous studies have shown an increase in the inhomogeneity of ventilation-perfusion ratio (V̇a/Q̇) after some underwater dives, presumably through the embolic effects of venous gas microemboli in the lung. Ground-based chamber studies simulating EVA have shown that venous gas microemboli occur in a large percentage of the subjects undergoing decompression, despite the use of prebreathe protocols to reduce dissolved N2 in the tissues. We studied eight crewmembers (7 male, 1 female) of the International Space Station who performed 15 EVAs (initial cabin pressure 748 mmHg, final suit pressure either ∼295 or ∼220 mmHg depending on the suit used) and who followed the denitrogenation procedures approved for EVA from the International Space Station. The intrabreath V̇a/Q̇ slope was calculated from the alveolar Po2 and Pco2 in a prolonged exhalation maneuver on the day after EVA and compared with measurements made in microgravity on days well separated from the EVA. There were no significant changes in intrabreath V̇a/Q̇ slope as a result of EVA, although there was a slight increase in metabolic rate and ventilation (∼9%) on the day after EVA. Vital capacity and other measures of pulmonary function were largely unaltered by EVA. Because measurements could only be performed on the day after EVA because of logistical constraints, we were unable to determine an acute effect of EVA on V̇a/Q̇ inequality. The results suggest that current denitrogenation protocols do not result in any major lasting alteration to gas exchange in the lung.

Related URLs:
http://jap.physiology.org/jap/99/6/2233.full.pdf

Detection of renal tissue and urinary tract proteins in the human urine after space flight

by on 9 June 2015in Biology & Biotechnology No comment

The urine protein composition samples of ten Russian cosmonauts (male, aged of 35 up to 51) performed long flight missions and varied from 169 up to 199 days on the International Space Station (ISS) were analyzed. As a control group, urine samples of six back-up cosmonauts were analyzed. We used proteomic techniques to obtain data and contemporary bioinformatics approaches to perform the analysis. From the total number of identified proteins (238) in our data set, 129 were associated with a known tissue origin. Preflight samples contained 92 tissue-specific proteins, samples obtained on Day 1 after landing had 90 such proteins, while Day 7 samples offered 95 tissue-specific proteins. Analysis showed that consistently present proteins in urine (under physiological conditions and after space flight) are cubilin, epidermal growth factor, kallikrein-1, kininogen-1, megalin, osteopontin, vitamin K-dependent protein Z, uromodulin. Variably present proteins consists of: Na(+)/K(+) ATPase subunit gamma, beta-defensin-1, dipeptidyl peptidase 4, maltasa-glucoamilasa, cadherin-like protein, neutral endopeptidase and vascular cell adhesion protein 1. And only three renal proteins were related to the space flight factors. They were not found in the pre-flight samples and in the back-up cosmonaut urine, but were found in the urine samples after space flight: AFAM (afamin), AMPE (aminopeptidase A) and AQP2 (aquaporin-2). This data related with physiological readaptation of water-salt balance. The proteomic analysis of urine samples in different phases of space missions with bioinformation approach to protein identification provides new data relative to biomechemical mechanism of kidney functioning after space flight.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/23967230

Changes of protein profile of human urine after long-term orbital flights

by on 9 June 2015in Biology & Biotechnology No comment

We analyzed protein profile of urine samples obtained from 7 Russian cosmonauts (age 35-51 years), participants of space flights on the International Space Station lasting for 169-199 days. Gradient chromatography with linear increase of eluent proportion was carried out in a system consisting of an Agilent 1100 chromatograph (Agilent Technologies Inc.) and a hybrid mass-spectrometer LTQ-FT Ultra (Thermo). The obtained results help to understand changes in the human body induced by space flight factors.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/24319748

Detection of renal and urinary tract proteins in urine before and after space flight

by on 9 June 2015in Biology & Biotechnology No comment

The urine protein composition (proteome) of healthy humans was analyzed using proteomic techniques to obtain data under normal physiological conditions and after six-month space flights. It was shown that, after long space flights, specific minor proteins are revealed in cosmonauts’ urine that can be identified as proteins coming from kidneys and urinary tracts.

Related URLs:
http://dx.doi.org/10.1134/S0362119713050125

Space habitation and microbiology: status and roadmap of space agencies

by on 9 June 2015in Biology & Biotechnology No comment

The ubiquitous nature of microbiology is reflected in the diversity of microbiological research and operational efforts at NASA. For example, the impact of microorganisms on other planets and the protection of Earth from the potential of microbial life elsewhere is the responsibility of the Office of Planetary Protection (http://planetaryprotection.nasa.gov/about). While the Office of Planetary Protection does not include forward or back contamination to or from a low Earth orbit, research platforms, such as the ISS, are being used to better understand the survival of microorganisms and corresponding contamination control in the extreme conditions of space (2, 4, 10). Another example is the NASA Center for Astrobiology, which focuses on the origin, evolution, distribution, and future of life in the universe (https://astrobiology.nasa.gov/). The large focus on microbiology is within its human exploration operations. NASA has historically set microbiological requirements, including stringent monitoring regimes, to mitigate risks to the health and performance of astronauts. Microorganisms can have both positive and negative impacts on many aspects of human spaceflight, including the risk and prevention of infectious diseases, performance of Environmental Control and Life Support Systems (ECLSS), spaceflight foods, and vehicle design and integrity. Even though a great amount of information has been obtained (1, 5, 7, 8), several key questions regarding the impact of microorganisms on human spaceflight still remain. Research into the uncertainties of risks that may affect crew health are the responsibility of the NASA Human Research Program (http://www.nasa.gov/exploration/humanresearch/). The research that addresses our fundamental understanding of space life science and its translation for benefits to the general public on Earth is the responsibility of NASA Space Biology.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/25130884

Direct proteome profiling of the blood serum in cosmonauts after long-term space missions

by on 9 June 2015in Biology & Biotechnology No comment

The aim of the present study was to examine the changes in the proteome profile of the blood serum in seven Russian cosmonauts after long-term space missions aboard International Space Station. Blood was sampled 45–60 days prior to and 1 and 7 days after the end of the mission. One day after the end of mission, we found a decrease in the peaks of β2-microglobulin and apolipoprotein CI. Additionally, we revealed shifts in functioning of the proteolytic systems of the blood, which were reflected in the changes in peak areas for specific proteins, such as fibrinogen, complement C3, high-molecular-weight kininogen, inhibitor of inter-α-trypsin, and clusterin.

Related URLs:
http://dx.doi.org/10.1134/S0362119714070196

Short term microgravity effect on isometric hand grip and precision pinch force with visual and proprioceptive feedback

by on 9 June 2015in Biology & Biotechnology No comment

Experiments executed on the upper limb are assuming increasing significance in the frame of the Human Physiology in space, for at least two reasons: the upper limb is the principal means of locomotion for the subject living in a space station; furthermore, fatigue can have a significant effect on the hand, for the ordinary work on board, and in particular for the extra-vehicular activities. The degradation of the performances affecting the muscular-skeletal apparatus can be easily recognized on the upper limb, by exerting specific scientific protocols, to be repeated through the permanence of the subject in weightlessness conditions. Another aspect relevant to the effect of microgravity on the upper limb is associated with the alteration of the motor control programs due to the different gravity factor, affecting not only the bio-mechanics of the subject, but in general all his/her psycho-physical conditions, induced by the totally different environment. Specific protocols on the upper limb can facilitate the studies on learning mechanisms for the motor control. The results of such experiments can be transferred to the Earth, useful for treatment of subjects with local traumas or diseases of the Central Nervous System.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0273117703010652

Space sickness on earth

by on 9 June 2015in Biology & Biotechnology No comment

During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find

Related URLs:
http://dx.doi.org/10.1007/BF02919464

Fluid shifts, vasodilatation and ambulatory blood pressure reduction during long duration spaceflight

by on 9 June 2015in Biology & Biotechnology No comment

Acute weightlessness in space induces a fluid shift leading to central volume expansion. Simultaneously, blood pressure is either unchanged or decreased slightly. Whether these effects persist for months in space is unclear. Twenty-four hour ambulatory brachial arterial pressures were automatically recorded at 1–2 h intervals with portable equipment in eight male astronauts: once before launch, once between 85 and 192 days in space on the International Space Station and, finally, once at least 2 months after flight. During the same 24 h, cardiac output (rebreathing method) was measured two to five times (on the ground seated), and venous blood was sampled once (also seated on the ground) for determination of plasma catecholamine concentrations. The 24 h average systolic, diastolic and mean arterial pressures (mean ± se) in space were reduced by 8 ± 2 mmHg (P = 0.01; ANOVA), 9 ± 2 mmHg (P < 0.001) and 10 ± 3 mmHg (P = 0.006), respectively. The nightly blood pressure dip of 8 ± 3 mmHg (P = 0.015) was maintained. Cardiac stroke volume and output increased by 35 ± 10% and 41 ± 9% (P < 0.001); heart rate and catecholamine concentrations were unchanged; and systemic vascular resistance was reduced by 39 ± 4% (P < 0.001). The increase in cardiac stroke volume and output is more than previously observed during short duration flights and might be a precipitator for some of the vision problems encountered by the astronauts. The spaceflight vasodilatation mechanism needs to be explored further.

Related URLs:
http://dx.doi.org/10.1113/jphysiol.2014.284869

Bioimpedance analysis of fluids and body composition under the conditions of short-term space flight or hypokinesia

by on 9 June 2015in Biology & Biotechnology No comment

Hydration status of humans was assessed by means of bioimpedancemetry on board the space station or under the conditions of antiorthostatic hypokinesia (AOSH). Water compartments of the body were decreased in a cosmonaut at the seventh day of a ten-day-long flight to the same degree as in a group of six testers by the seventh day of AOSH (−8°): the amount of total body fluids and intracellular and extracellular volumes were decreased by 5.6–6.5% as compared to the baseline level. The changes in body composition of a cosmonaut during flight were similar to the changes observed in testers during AOSH: lean body weight, which was determined by bioimpedancemetry, was insignificantly decreased, whereas the adipose component of body weight was, on the contrary, increased. It was concluded that the hydration level of the human body was decreased and the amount of body fat was increased during a short-term space flight. It was also shown that the hydration status and composition of the human body were changed in a similar way under the conditions of both AOSH and space flight, which indicates that this ground-based model is adequate for simulation of hydration changes caused by microgravity.

Related URLs:
http://dx.doi.org/10.1134/S0362119706050197