Characteristics of blood plasma proteome changes associated with the hemorrhagic purpura of cosmonauts on the first day after long-term space missions.

The interest in the role of the gravitational factor during landing after long-term space flights (SF) leads to the search for various innovative approaches to assessing the compliance of external changes observed by clinicians. The results of special research methods such as Omics technologies that may reflect physiological responses to the conditions created during landing are of great interest. Our purpose is to compare the blood plasma proteome changes associated with the trauma and endothelial dysfunction processes prior to launch and on the day of landing, as well as the groups of cosmonauts with and without the secondary hemorrhagic purpura. In our study, the concentrations of 125 plasma proteins in 18 Russian cosmonauts, measured using targeted proteomic analysis based on liquid chromatography and tandem mass spectrometry were analyzed. The results reveal the trends of 12 proteins participating in the processes that trigger hemorrhagic purpura under the effect of re-entry g-forces. Exposure to intense g-forces and return to the gravity are the key factors for external manifestations of changes in the body systems induced by a long-term stay in space microgravity. Our results may be useful for further research to experts in gravitational physiology, aviation and space medicine.

[Effects of artificial gravity on perimetry results]. / Vliyanie iskusstvennoi gravitatsii na izmenenie perimetricheskikh pokazatelei organa zreniya.

The active exploration of space requires minimizing negative effects induced by weightlessness (microgravity). Risk reduction can be achieved with the use of artificial gravity created by short-radius centrifuge (SRC). Short-radius centrifuge causes redistribution of body liquids towards the caudal portion of the body imitating a vertical human pose. Presently, studying the safety of this prevention method for the human body in general, and for the visual system in particular, is one of the priority tasks of space medicine. PURPOSE: To study the effects of artificial gravity on the perimetry measurements of the eye. MATERIAL AND METHODS: The study included 9 volunteers (men) aged 31.2±6 years (from 25 to 40 years). Each man was subjected to three rotations on SRC. The operative factor in the tests was overloads in the «head-pelvis¼ direction. Rotations were carried out in three different modes with varying maximum overload value at the feet level of up to 2.0; 2.4; 2.9 G. Pulsar-perimetry was carried out before and 1-2 hours after the rotations estimating the mean threshold of retinal photosensitivity Mean Sensitivity (MS), mean loss of sensitivity Mean Defect (MD), square root of Loss Variance (sLV); the Bebie curve; additionally, cluster analysis was performed. RESULTS: Mean threshold of retinal photosensitivity, mean loss of photosensitivity, square root of Loss Variance by Pulsar-perimetry before (MS=22.75 dB; MD= -0.6 dB; sLV=1.5) and after rotations on SRC (in Mode 1: 23.4; -0.2; 1.5, Mode 2: 23.2; -0.4; 1.4 and Mode 3: 23.5; -0.8; 1.4 respectively) did not change significantly. No adverse phenomena were detected in the eyes. CONCLUSIONS: There were no significant changes in the visual fields of the test subjects after rotations in three different modes according to Pulsar-perimetry data, which gives reason to tentatively conclude that using SCR in these modes is safe for the visual sensory system. According to preliminary data, this method can be successfully used to reduce the risk of long-term space flights and prevent unwanted phenomena caused by weightlessness.

[DEVELOPMENT OF HUMAN CARDIOVASCULAR DECONDITIONING ON THE STAGE OF RETURNING TO EARTH AFTER STAY IN MICROGRAVITY].

The authors present the results of retrospective analysis of earlier published papers and reports, and also own observations of cardiovascular deconditioning in cosmonauts and astronauts returning from microgravity. Benefits of in-flight physical exercises to g-tolerance during descent and post-recovery orthostatic stability are discussed.

[Cosmonauts' tolerance of the chest-back G-loads during ballistic and automatically controlled descents of space vehicles].

Analysis of cosmonauts' +Gx tolerance on the stage of ballistic or automatically controlled Soyuz descent after missions to the International space station of varying duration was performed. As compared with automatically controlled descents, tolerance of descent re-entry +G(x) following short (8-14 d) missions was marked by reliably more frequent instances of visual disorders, difficult breathing, sensation of a lump in the throat and vestibulovegetative disorders (p < 0.05). The ballistic but not controlled re-entry after long-term mission provoked visual disorders, difficulties with breathing and speech, and vestibulovegetative disorders more often (p < 0.05). A considerable HR rise due to the ballistic rather than control descent was associated with re-entry and the main parachute re-hooking for symmetrical suspension; respiration rate was the highest during parachuting. By and large, these factual data infer that the ballistic descent after various periods in spaceflight microgravity, especially after extended space missions (164-169 d), led to a dramatic loss in the body functional reserves.

[Individual prediction by the analysis of preflight ECG data of cardiac function disorders in cosmonauts during standard deorbit after long-term space flights and in the period of postflight observation].

ECG records of 25 cosmonauts--members of 30 long-term Mir and ISS missions (73- to 197-day long) in the period of 1995-2007 were analyzed. The ECG records were made during medical selection, clinical-physiological investigations (KFO) before launch, insertion and standard descent, and post-flight KFO. No negative trends were discovered in 70% (n=21) of ECG records during insertion and descent of cosmonauts who had not have significant ECG deviations before flight. In 20% of ECG records (n=6) pre-launch individual properties of cardiac rhythm, conduction and end of the ventricular complex became more pronounced in the period of descent persisting after landing. In 10% of ECG records (n=3) the predicted ECG deviations were not found This was the first time when dynamic analysis of ECG records made on the stages of selection and pre-launch training was successful in predicting of 90% (n=27 of 30) of cardiac function deviations during descent. At the start of rehabilitation from long-term missions essentially each of the cosmonauts displayed ECG deviations which were more considerable as compared with the KFO and descent records.

[Prediction of cardiac function deviations (ECG data) in the course of permanent cosmonaut's monitoring starting from selection till return to earth after short-duration space flight].

Analyzed were deviations in cardiac function in 29 cosmonauts with previous aviation and other occupations ranging of 29 to 61 y.o. who made 8- to 30-day space flights (totai number of flights = 34) between 1982 and 2006. The deviations were identified in ECG records collected during clinical selection, clinical physiological examination (CPE) before flight, insertion and deorbit in transport vehicles, and post-flight CPE. Based on the analysis, the cosmonauts were distributed into three groups. The first group (55.2% of the cosmonauts) did not exhibit noticeable shifts and unfavorable trends in ECG at any time of the period of observation. The second group (34.5%) showed some deviations during selection and pre-flight CPE that became more apparent in the period of deorbit and were still present in post-flight ECG records. The third group (10.3%) displayed health-threatening deviations in cardiac function during deorbit. These findings give start to important investigations with the purpose to define permissible medical risks and ensuing establishment and perfection of medical criteria for candidates to cosmonauts with certain health problems.

[On medical screening of civilian candidates for cosmonauts by exposure to the head-to-pelvis acceleration profiles].

The subject of analysis was the data on +3 and +5 Gz tolerance of 130 civilian non-pilot applicants for cosmonauts (men and women, aged 23 to 55) gathered over the past 30 years. Length of the centrifuge arm was 7.25 meters and the total number of primary centrifuge runs was 309. For nearly every second of the applicants (46.7%) acceleration at +5 Gz was an ordeal causing distinct vascular or coronary decompensation. Thus, 29.7% exhibited various combinations of brief visual disturbances, tachycardia, tachypnea, and systolic arterial pressure in the shoulders; in 17%, visual disturbances and/or their precursors were combined with exaggerated cardio-vascular functional parameters, arrhythmia, and serious vegetative disorders. Most of those who had failed to endure the first centrifugation were unable to improve G tolerance during next runs; indeed, they showed negative G-tolerance dynamics. G intolerance grew in significance or was exacerbated by new disorders and their combinations. These results testify against exposure of non-pilot applicants for cosmonauts to +5 G, during the primary medical screening.

+Gx tolerance by females following long-duration simulated and spaceflight microgravity.

The purpose of this study was to test a variety of microgravity countermeasures and anti-G suit (AGS) in long-term bed-rest and to approve them during 169-days space flight.

[G-tolerance of female cosmonauts during descent in space flights of 8 up to 169 days in duration]. / Perenosimost' peregruzok zhenshchinami-kosmonavtami na uchastke spuska v kosmicheskikh poletakh dlitel'nost'iu ot 8 do 169 sutok.

Investigations into g-tolerance of female cosmonauts during descent in space flights of varying duration are topical for the present day, as there are little data on this issue. Tolerance of +Gz-loads during descent was analyzed based on the data about 4 female cosmonauts in 5 space flights. The space flights were conventionally divided into short- (8-16 days) and long-term (169 days). In two space flights (16 and 169-d long), tubeless anti-g suit Centaur was warn during descent. In these space flights, g-tolerance of females was quite satisfactory advocating for the possibility for women to fly to space without any constraints. When the anti-g suit was not used, female physiological systems were stressed heavier than male. The spacesuit smoothed away this difference. Our results evidence a distinct positive effect of wearing the anti-g suit by female cosmonauts during descent as it reduces stress to their physiological systems.

[The effect of G-loads on gravity tolerance of monkeys Macaca rhesus during antiorthostatic hypokinesia]. / Vliianie gravitatsionnykh nagruzok v usloviiakh antiortostaticheskoi gipokinezii na gravitatsionnuiu ustoichivost' obez'ian makak rezusov.

Reported are results of 200 centrifuge runs of 24 monkeys Macaca mulatta. Microgravity effects were simulated by 4-wk immobilization with the head tilted down at -6 degrees. The investigation was divided into two series. During series-1, one group of animals was not exposed to centrifugal training, whereas the other group was exposed to +Gz at the magnitudes of 1.2, 1.4 and 1.6 G for 30-40 min 4 to 5 times a week. In series-2, again one group of animals was not trained on the centrifuge but the other was trained at +1.2 Gz for 30 min 2 or 3 times a week. Functional testing by 30-s runs at +3 Gz was performed before and after head-down immobilization. Deterioration of g-load tolerance following simulated microgravity in both groups of untrained macaques was ascribed to the deconditioning effect of simulated microgravity on the body systems. Centrifugal training had, as a rule, positive effect on g-tolerance of the animals though it failed to fully eliminate the negative consequences of simulated microgravity. This means that search after optimal protocols of application of artificial gravity generated by centrifuge needs to be continued. Evaluation of the effectiveness of combining centrifugation with other countermeasures against the adverse effects of microgravity and development of associated protocols can be another area of future research.

Muscle derived serum enzyme accumulation after +Gz acceleration test in Rhesus monkeys exposed to bed rest.

It is known that several hours of intensive muscle tension result in accumulation of muscle derived enzymes and structural proteins (see review by Clarkson, 1997). We have assumed that, firstly, acute exposure to hypergravity may induce accumulation of serum creatine phosphokinase (CPK), and, secondly, level of that accumulation may be considerably altered after long term hypokinesia.

[An experimental validation of pharmacological agents to arrest the vestibulo-autonomic syndrome (motion sickness)]. / Eksperimental'noe obosnovanie farmakologicheskikh sredtsv kupirovaniia vestibulo-vegetativnogo sindroma (bolezn' dvizheniia).

The results of development and experimental evaluation of the efficiency of pharmacological means of cupping the vestibulo-vegetative syndrome in man are presented. A model and procedure of evaluation of pharmacological cupping of the Vestibulo-vegetative syndrome are developed. The intramuscular injection of the mixture containing ephedrine, promethazine hydrochloride and strychnine (25, 50, and 1 mg, respectively) appeared most effective.

[Role of age in +Gz and +Gx tolerance by female candidates to astronauts]. / Vliianie vozrasta na perenosimost' peregruzok +Gz i +Gx zhenshchinami pri otbore v kosmonavty.

Analyzed was the role of age in the tolerance of +Gz (up to 5 units) and +Gx (up to 8 units) by female candidates to cosmonauts on the stage of initial centrifuge selection in the years of 1979 through to 1993. Selection was made of 26 healthy non-flying women aged 23 to 39 who were divided into 4 groups with 5-year intervals. Female tolerance of g-loads and shifts in a number of physiological parameters during centrifugation were discovered to be age-dependent. The poorest tolerance of +Gz and +Gx loads was typical of women below 25 years, the best, at the age of 31 to 40 years. It was stated that tolerance of these demanding g-loads by women, especially below 30, was generally worse compared with men. There were also some distinctions in the cardiovascular response in women and men. These results point to the significance of centrifugation in selection female candidates to cosmonauts irrespective of their age.

[Tolerance of +Gx-loads by females before and after a 120-day hypokinesia]. / Perenosimost' peregruzok napravleniia +Gx zhenshchinami do i posle 120-sutochnoi gipokinezii.

The goal of the work was to study female tolerance of g-loads before and after simulated weightlessness, and evaluate the effectiveness of countermeasures and anti-g means proposed for space flight. Centrifuge with a 7.25 m arm was used for 29 runs of 8 female subjects. The subjects were exposed to the transverse loads (+GX) at 8.2 g on a special regimen with the total run time of 9 min to simulate the ballistic descent from orbit in a SOYUZ-TM vehicle. Baseline tolerance of the females to transverse loads up to +8GX was good and satisfactory. Following 120 days of bed rest without the countermeasures or the anti-g suit g-tolerance was significantly lowered as evidenced by visual disorders in 67% of cases and exaggerated, if compared with the pre-hypokinesia levels, heart and respiration rates, i.e. 20% and 23.5%, respectively. The countermeasures and anti-g suit Centaur maintained g-tolerance at essentially the baseline level and precluded visual disorders. Results of the study speak in favor of the countermeasures and anti-g means used by the females in simulated long-duration weightlessness which can be recommended for the final phase of extended space mission.