Ophthalmic changes have occurred in a subset of astronauts on International Space Station missions. Visual deterioration is considered the greatest human health risk of spaceflight. Affected astronauts exhibit higher concentrations of 1-carbon metabolites (e.g., homocysteine) before flight. We hypothesized that genetic variations in 1-carbon metabolism genes contribute to susceptibility to ophthalmic changes in astronauts. We investigated 5 polymorphisms in the methionine synthase reductase (MTRR), methylenetetrahydrofolate reductase (MTHFR), serine hydroxymethyltransferase (SHMT), and cystathionine beta-synthase (CBS) genes and their association with ophthalmic changes after flight in 49 astronauts. The number of G alleles of MTRR 66 and C alleles of SHMT1 1420 both contributed to the odds of visual disturbances. Preflight dehydroepiandrosterone was positively associated with cotton wool spots, and serum testosterone response during flight was associated with refractive change. Block regression showed that B-vitamin status and genetics were significant predictors of many of the ophthalmic outcomes that we observed. In one example, genetics trended toward improving (P = 0.10) and B-vitamin status significantly improved (P < 0.001) the predictive model for refractive change after flight. We document an association between MTRR 66 and SHMT1 1420 polymorphisms and spaceflight-induced vision changes. This line of research could lead to therapeutic options for both space travelers and terrestrial patients.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26316272
Research Containing: Human
ELITE S2 – AN INSTRUMENT FOR MOTION ANALYSIS ON BOARD THE INTERNATIONAL SPACE STATION
This paper describes the activities for utilization and control of ELITE S2 on board the International Space Station (ISS). ELITE S2 is a payload of the Italian Space Agency (ASI) for quantitative human movement analysis in weightlessness. Within the frame of a bilateral agreement with NASA, ASI has funded a number of facilities, enabling different scientific experiments on board the ISS. ELITE S2 has been developed by the ASI contractor Kayser Italia, delivered to the Kennedy Space Center in 2006 for pre-flight processing, launched in 2007 by the Space Shuttle Endeavour (STS-118), integrated in the U.S. lab and used during the Increments 16 and 17 through 2008. The ELITE S2 flight segment comprises equipment mounted into an Express Rack and a number of stowed items to be deployed for experiment performance (video cameras and accessories). The ground segment consists in a User Support Operations Center (based at Kayser Italia) enabling real-time payload control and a number of User Home Bases (located at the ASI and PIs premises), for the scientific assessment of the experiment performance. Two scientific protocols on reaching and cognitive processing have been successfully performed in five sessions involving two ISS crewmembers: IMAGINE 2 and MOVE.
Expression of p53-Regulated Proteins in Human Cultured Lymphoblastoid TSCE5 and WTK1 Cell Lines during Spaceflight
The aim of this study was to determine the biological effects of space radiations, microgravity, and the interaction of them on the expression of p53-regulated proteins. Space experiments were performed with two human cultured lymphoblastoid cell lines: one line (TSCE5) bears a wild-type p53 gene status, and another line (WTK1) bears a mutated p53 gene status. Under 1 gravity or microgravity conditions, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station for 8 days without experiencing the stress during launching and landing because the cells were frozen during these periods. Ground control samples were simultaneously cultured for 8 days in the CBEF on the ground for 8 days. After spaceflight, protein expression was analyzed using a PanoramaTM Ab MicroArray protein chips. It was found that p53-dependent up-regulated proteins in response to space radiations and space environment were MeCP2 (methyl CpG binding protein 2), and Notch1 (Notch homolog 1), respectively. On the other hand, p53-dependent down-regulated proteins were TGF-β, TWEAKR (tumor necrosis fac- tor-like weak inducer of apoptosis receptor), phosho-Pyk2 (Proline-rich tyrosine kinase 2), and 14-3-3θ/τ which were affected by microgravity, and DR4 (death receptor 4), PRMT1 (protein arginine methyltrans- ferase 1) and ROCK-2 (Rho-associated, coiled-coil containing protein kinase 2) in response to space radi- ations. ROCK-2 was also suppressed in response to the space environment. The data provides the p53- dependent regulated proteins by exposure to space radiations and/or microgravity during spaceflight. Our expression data revealed proteins that might help to advance the basic space radiation biology.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/22374402
Observation of radiation environment in the International Space Station in 2012–March 2013 by Liulin-5 particle telescope
Since June 2007 the Liulin-5 charged particle telescope, located in the spherical tissue-equivalent phantom of the MATROSHKA-R project onboard the International Space Station (ISS), has been making measurements of the local energetic particle radiation environment. From 27 December 2011 to 09 March 2013 measurements were conducted in and outside the phantom located in the MIM1 module of the ISS. In this paper Liulin-5 dose rates, due to galactic cosmic rays and South Atlantic Anomaly trapped protons, measured during that period are presented. Particularly, dose rates and particle fluxes for the radiation characteristics in the phantom during solar energetic particle (SEP) events occurring in March and May 2012 are discussed. Liulin-5 SEP observations are compared with other ISS data, GOES proton fluxes as well as with solar energetic particle measurements obtained onboard the Mir space station during previous solar cycles.
Related URLs:
http://adsabs.harvard.edu/abs/2014JSWSC…4A..32S
Characteristics of local human skeleton responses to microgravity and drug treatment for osteoporosis in clinic
Analysis of the results of long term investigations of bones in cosmonauts on board Mir orbital sta tion(OS) and International Space Station (ISS) (n = 80) was performed. Theoretically predicted (evolution ary predefined) change in mass of different skeleton bones was found to be correlated (r = 0.904) with the position relative to Earth’s gravity vector. Vector dependence of bone loss results from local specificity of expression of bone metabolism genes, which reflects mechanical prehistory of skeleton structures in the evo lution of Homo erectus. Genetic polymorphism is accountable for high individual variability of bone loss, which is attested by the dependence of bone loss rate on polymorphism of certain genetic markers of bone metabolism. The type of the orbital vehicle did not affect the individual specific stability of the bone loss ratio in different segments of the skeleton. This fact is considered as a phenotype fingerprint of local metabolism in the form of a locus specific spatial structure of distribution of non collagen proteins responsible for posi tion regulation of endosteal metabolism. Drug treatment of osteoporosis (n = 107) evidences that recovery rate depends on bone location; the most likely reason is different effectiveness of local osteotropic interven tion into areas of bustling resorption.
Related URLs:
http://link.springer.com/article/10.1134/S0362119714070184
THE ASTRONAUT-ATHLETE: OPTIMIZING HUMAN PERFORMANCE IN SPACE
Abstract: Hackney, KJ, Scott, JM, Hanson, AM, English, KL, Downs, ME, and Ploutz-Snyder, LL. The astronaut-athlete: optimizing human performance in space. J Strength Cond Res 29(12): 3531–3545, 2015—It is well known that long-duration spaceflight results in deconditioning of neuromuscular and cardiovascular systems, leading to a decline in physical fitness. On reloading in gravitational environments, reduced fitness (e.g., aerobic capacity, muscular strength, and endurance) could impair human performance, mission success, and crew safety. The level of fitness necessary for the performance of routine and off-nominal terrestrial mission tasks remains an unanswered and pressing question for scientists and flight physicians. To mitigate fitness loss during spaceflight, resistance and aerobic exercise are the most effective countermeasure available to astronauts. Currently, 2.5 h·d−1, 6–7 d·wk−1 is allotted in crew schedules for exercise to be performed on highly specialized hardware on the International Space Station (ISS). Exercise hardware provides up to 273 kg of loading capability for resistance exercise, treadmill speeds between 0.44 and 5.5 m·s−1, and cycle workloads from 0 and 350 W. Compared to ISS missions, future missions beyond low earth orbit will likely be accomplished with less vehicle volume and power allocated for exercise hardware. Concomitant factors, such as diet and age, will also affect the physiologic responses to exercise training (e.g., anabolic resistance) in the space environment. Research into the potential optimization of exercise countermeasures through use of dietary supplementation, and pharmaceuticals may assist in reducing physiological deconditioning during long-duration spaceflight and have the potential to enhance performance of occupationally related astronaut tasks (e.g., extravehicular activity, habitat construction, equipment repairs, planetary exploration, and emergency response).
Related URLs:
http://journals.lww.com/nsca-jscr/Fulltext/2015/12000/The_Astronaut_Athlete___Optimizing_Human.35.aspx
The effect of microgravity on the in vitro NK cell function during six International Space Station Missions
The level of natural killer (NK) cytotoxic activity was measured during co-cultivation of human lymphocytes and target cells (K- 562) in microgravity. Flight experiments were carried out using special instrumentation, the “Fibroblast-1” cassettes, in the frame of Russian scientific program during six ISS missions. Lymphocyte suspensions from human venous blood were used in experiments during short-term flights on six ISS missions (7 –12). Russian space crew members performed the experiments after Soyuz docking. The first step was mixing lymphocytes and 3H-labeled K-562 cells and their incubation at 37°C during 24 hs; the second step was filtration of the cell suspension. The frozen medium and filters were analyzed for the cytokine level and cytotoxic activity after landing. It was found that lympho- cytes with different basal levels of cytotoxic activity kept the ability of recognizing and lysing malignant cells. In micrograv- ity, cytotoxity increased to 160% of the basal levels. Donor indi- vidual features modulated the magnitude of the increase. The measurement of interleukin levels (TNF-α, IL-1, IL-2) in medi- um showed that synthesis of TNF-α increased during cell co-cul- tivation in microgravity. The level of IL-2 was very low in flight and ground control samples. The production of IL-1 by lympho- cytes decreased after in-flight incubation. The results indicate that microgravity did not disturb the cytotoxic function of immune cells in vitro during 24 h incubation with specific target cells.
Related URLs:
http://link.springer.com/article/10.1007%2FBF02919470
Circadian misalignment affects sleep and medication use before and during spaceflight
Sleep deficiency and the use of sleep-promoting medication are prevalent during spaceflight. Operations frequently dictate work during the biological night and sleep during the biological day, which contribute to circadian misalignment. We investigated whether circadian misalignment was associated with adverse sleep outcomes before (preflight) and during spaceflight missions aboard the International Space Station (ISS). Actigraphy and photometry data for 21 astronauts were collected over 3,248 days of long-duration spaceflight on the ISS and 11 days prior to launch (n = 231 days). Sleep logs, collected one out of every 3 weeks in flight and daily on Earth, were used to determine medication use and subjective ratings of sleep quality. Actigraphy and photometry data were processed using Circadian Performance Simulation Software to calculate the estimated endogenous circadian temperature minimum. Sleep episodes were classified as aligned or misaligned relative to the estimated endogenous circadian temperature minimum. Mixed-effects regression models accounting for repeated measures were computed by data collection interval (preflight, flight) and circadian alignment status. The estimated endogenous circadian temperature minimum occurred outside sleep episodes on 13% of sleep episodes during preflight and on 19% of sleep episodes during spaceflight. The mean sleep duration in low-Earth orbit on the ISS was 6.4 ± 1.2 h during aligned and 5.4 ± 1.4 h (P o 0.01) during misaligned sleep episodes. During aligned sleep episodes, astronauts rated their sleep quality as significantly better than during misaligned sleep episodes (66.8±17.7 vs. 60.2±21.0, Po0.01). Sleep-promoting medication use was significantly higher during misaligned (24%) compared with aligned (11%) sleep episodes (Po0.01). Use of any medication was significantly higher on days when sleep episodes were misaligned (63%) compared with when sleep episodes were aligned (49%; Po0.01). Circadian misalignment is associated with sleep deficiency and increased medication use during spaceflight. These findings suggest that there is an immediate need to deploy and assess effective countermeasures to minimize circadian misalignment and consequent adverse sleep outcomes both before and during spaceflight.
Related URLs:
http://www.nature.com/articles/npjmgrav201519
FURTHER ANALYSIS OF THE SPACE SHUTTLE EFFECTS ON THE ISS SAA DOSES
The data from the R3DE instrument of ESA’s EXPOSE-E mission outside the ISS at the European Technological Expose Facility (EuTEF) on the ESA Columbus module shows that the docking of the Space Shuttle with the International Space Station (ISS) decreased the South-Atlantic Anomaly (SAA) maxima dose rates from about 1500 Gy h-1 down to 600-700 Gy h-1 or by factor of 2. The dose rate data at the same time from another Bulgarian built instrument (R3DR) of the EXPOSE-R mission outside the Russian “Zvezda” module showed that: 1) before the Space Shuttle docking, the SAA dose rates measured with R3DR were higher (2500 Gy h-1) than the R3DE data; 2) The relative decrease of the SAA dose rates after the shuttle docking was only by a factor of 1.25. These differences are explained by the smaller shielding of R3DR from the body of ISS and by the larger distance of it from the body of Space Shuttle. Very similar data, but with smaller dose rates were obtained with a third Bulgarian built instrument (Liulin-5) inside Russian “Pirs” module. The analysis of the ascending/descending SAA dose rate maxima of the three instruments shows that the effect can be simply explained by the additional shielding against the 30 to 150 MeV protons of the SAA, provided by the 78 tons Shuttle to the instruments and by changing of the ISS 3D mass distribution when the ISS rotates.
Related URLs:
http://iafastro.directory/iac/archive/browse/IAC-11/A1/4/9918/
Dysfunctional vestibular system causes a blood pressure drop in astronauts returning from space
It is a challenge for the human body to maintain stable blood pressure while standing. The body’s failure to do so can lead to dizziness or even fainting. For decades it has been postulated that the vestibular organ can prevent a drop in pressure during a position change–supposedly mediated by reflexes to the cardiovascular system. We show–for the first time–a significant correlation between decreased functionality of the vestibular otolith system and a decrease in the mean arterial pressure when a person stands up. Until now, no experiments on Earth could selectively suppress both otolith systems; astronauts returning from space are a unique group of subjects in this regard. Their otolith systems are being temporarily disturbed and at the same time they often suffer from blood pressure instability. In our study, we observed the functioning of both the otolith and the cardiovascular system of the astronauts before and after spaceflight. Our finding indicates that an intact otolith system plays an important role in preventing blood pressure instability during orthostatic challenges. Our finding not only has important implications for human space exploration; they may also improve the treatment of unstable blood pressure here on Earth.
Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26671177