Medical Issues Associated with Winter Survival Training.

INTRODUCTION: During active phases of manned spaceflight there is a possibility of a spacecraft landing at any point traversed by its orbital path on the Earth. Survival training after emergency landing is an important and vital part of pre-mission preparations. In this paper we analyze medical issues associated with winter survival training in marshy and forested terrain.METHODS: From 2011 to 2019, 50 International Space Station crews participated in winter survival training. Crewmembers included Roscosmos, NASA, CSA, ESA, and JAXA astronauts, spaceflight participants, and instructors. Medical protocols and training final reports were analyzed for conditions and medical events.RESULTS: The health status of crewmembers during training was nominal. Temperature sensation was reported as comfortable or moderately cold during daytime and moderately cold or cold during nighttime. SpO2 (blood oxygen saturation) and heart rate recorded during training did not exceed normal values. SpCO (blood carbon monoxide saturation) generally was within normal limits. All participating crewmembers lost some bodyweight, from 0.15.5 kg (average 2.1 kg). Over the course of winter survival training there were 32 medical and environmental events requiring medical intervention. For two of the crewmembers requiring medical intervention, training was subsequently canceled.DISCUSSION: Winter survival training has successfully prepared spaceflight crews for the possibility of off-nominal landings in challenging terrain under adverse conditions. As this training involves high fidelity flight-like survival equipment and assigned flight crewmembers, the medical problems described here should closely reflect type and prevalence of events during an actual contingency scenario.Kireev KS, Grishin AP, Dowell GL. Medical issues associated with winter survival training. Aerosp Med Hum Perform. 2021; 92(8):676680.

The molecular mechanisms driving physiological changes after long duration space flights revealed by quantitative analysis of human blood proteins.

BACKGROUND: The conditions of space flight have a significant effect on the physiological processes in the human body, yet the molecular mechanisms driving physiological changes remain unknown. METHODS: Blood samples of 18 Russian cosmonauts who had conducted long-duration missions to the International Space Station were collected 30 days before launch and on the first and seventh days after landing. RESULTS: A panel of 125 proteins in the blood plasma was quantitated by a well-established and highly regarded targeted mass spectrometry approach. This method involves the monitoring of multiple reactions in conjunction with stable isotope-labeled standards at the University of Victoria - Genome BC Proteomics Centre. CONCLUSIONS: Reduction of circulating plasma volume during space flight and activation of fluid retention at the final stage of the flight affect the changes in plasma protein concentrations present in the first days after landing. Using an ANOVA approach, it was revealed that only 1 protein (S100A9) reliably responded to space flight conditions. This protein plays an important role in the functioning of the endothelium and can serve as a marker for activation of inflammatory reactions. Concentrations of the proteins of complement, coagulation cascades, and acute phase reactants increase in the blood of cosmonauts as measured the first day after landing. Most of these proteins' concentrations continue to increase by the 7th day after space flight. Similar dynamics are observed for proteases and their inhibitors. Thus, there is a shift in proteolytic blood systems, which is necessary for the restoration of muscle tissue and maintenance of oncotic homeostasis.

Kidney function and urine protein composition in healthy volunteers during space station fitness tests.

BACKGROUND: There is a close physiological connection between muscular activity and kidney function. During physical exercise (PE) the qualitative and quantitative composition of urine changes. This paper explores the influence of moderate PE on urine protein composition. The study of urine protein composition will help to make corrections to the existing methods of countermeasures. METHODS: There were 10 healthy men who exercised on a treadmill similar to the one onboard the International Space Station. We analyzed their urinary proteome composition, potassium level, sodium level, and their level of osmotically active substances before and after PE. RESULTS: After moderate PE, a small increase in urine flow speed and a constant glomerular filtration rate were noted. The average-group index of total protein excretion within the urine was reliably increased. From the 148 proteins identified in the urine, 64 were associated with known tissue origin. We found that protein penetration into the urine had a positive correlation with their tissue expression. Selectivity of the glomerular barrier during PE decreased and high-molecular weight proteins penetrated through the glomerular barrier more easily after PE. DISCUSSION: Performance of moderate intensity physical exercise of short duration did not lead to an increase in the glomerular filtration rate nor did diuresis increase above the limits of baseline variability. However, the protein excretion rate increased after PE. We also observed that protein composition drift indicated a change in the set of biological processes in which a given protein participated, in some cases activating, in some cases inactivating them.

Permanent proteins in the urine of healthy humans during the Mars-500 experiment.

Urinary proteins serve as indicators of various conditions in human normal physiology and disease pathology. Using mass spectrometry proteome analysis, the permanent constituent of the urine was examined in the Mars-500 experiment (520 days isolation of healthy volunteers in a terrestrial complex with an autonomous life support system). Seven permanent proteins with predominant distribution in the liver and blood plasma as well as extracellular localization were identified. Analysis of the overrepresentation of the molecular functions and biological processes based on Gene Ontology revealed that the functional association among these proteins was low. The results showed that the identified proteins may be independent markers of the various conditions and processes in healthy humans and that they can be used as standards in determination of the concentration of other proteins in the urine.

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

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, ß-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.

Detection of renal and urinary tract proteins before and after spaceflight.

BACKGROUND: The recent evolution of genomics and subsequently proteomics offers a major advance in the ability to understand individual human variation in disease and the molecular level changes induced by certain environmental exposures. This original study examines urinary proteome composition to enable the understanding of molecular homeostatic mechanisms in spaceflight and presents the potential for early detection of subclinical disease, microgravity risk mitigation strategies, and countermeasure development for exploration-class missions. METHODS: The urinary proteome composition of six Russian cosmonauts (men, ages 35-51) who flew long-duration missions of 169-199 d was determined 30 d before flight and compared to repeat studies 1 and 7 d postflight. RESULTS: There were 430 proteins identified. Of those, 15 proteins originated in the renal tissues. Of the 15 urinary proteins, 10 were consistently present in the urine. However, the presence of five of the urinary proteins--neutral endopeptidase (NEP), afamin (AFAM), aquaporin-2 (AQP2), aminopeptidase A (AMPE), and dipeptidyl peptidase 4 (DPP4)--was dependent on spaceflight exposure. DISCUSSION: Proteomic investigation of pre- and postflight urine and bioinformation approaches to proteome analysis provide important data relative the mechanism of kidney function in spaceflight. In this initial study, we determined that the evaluation of urinary proteins may help investigators understand changes that are occurring in microgravity. Once additional ground-based and in-flight data are collected, it is feasible to develop targeted studies for tracking specific spaceflight related changes, determine countermeasure and risk-mitigation effectiveness, and possibly detect subclinical disease in flight crewmembers.