Some approaches to prophylactic measures in a martian expedition

Physiological and methodological principles of the organization of physical training (PT) and its computerization during a space flight to Mars under the conditions of autonomous activity of the crew, including interaction with onboard medical systems, self-maintenance of health, preventive measures, diagnostic examinations, and, if necessary, treatment, are discussed. The conditions of unusually long-term autonomous space flights make the ground-based monitoring of the state of health of crew members substantially more difficult, which calls for computerization of the control over the crew members’ health, including prophylactic measures. The situation is further complicated because it is impossible to receive the necessary information from, and transmit it to, the spacecraft in a real-time mode or to quickly return the crew to Earth in case of an emergency. Under these conditions, physical prevention should be based on an onboard automated expert system ensuring the control over the activities of all crew members aimed at optimizing their psychophysical state. The problems of the control of training, including the use of an onboard automated expert system, are discussed.     

Effectiveness of Different Training Programs for Physical Performance Maintenance under the Condition of Low Motor Activity

Investigations made by the World Health Organization have shown that lack of physical activity and sedentary lifestyle are among ten major causes for death and disability. Typically, studies of the negative effects of reduced physical activity and their prevention face difficulties of providing standard conditions. These issues were obviated successfully in the Mars-500 experiment on simulation of a space exploration mission. The sample of subjects consisted of six volunteers from Russia, France, Italy, and China, who were isolated in a limited space for 520 days. To prevent the negative effects of low physical activity, the volunteers performed resistive and cyclic exercises in different periods of isolation. The study was designed with two pauses in the training program. Physical performance was evaluated with an incremental loading test, maximal voluntary effort test (Russian–Austrian MDS resistive exercise system), and PWC-170 (bicycle ergometer). The level of physical performance of the subjects in this experiment never degraded to below baseline values. The proposed training system comprising different kinds of exercise ensured stability or improvement physical performance as compared with the baseline level.     

Comparative efficiency of different regimens of locomotor training in prolonged space flights as estimated from the data on biomechanical and electromyographic parameters of walking

Biomechanical and electromyographic characteristics of locomotion were studied before and after a space flight on days 3, 7, and 10 after landing in 18 participants of prolonged space missions on board the International Space Station. It has been shown that microgravity causes significant changes in biomechanical and electromyographic characteristics of walking, such as a decrease in the amplitude of angular displacement in leg joints, a decrease in the double step length, and an increase in the electromyographic costs of locomotion. It has been also shown that interval locomotor physical training, such as alternation of running and walking, in prolonged space flights prevents an increase in the physiological costs of locomototions after a space flight and provides more efficient maintenance of the neuromuscular system’s performance after a flight. Cosmonauts who performed interval locomotor training had fewer changes in biomechanical and electromyographic characteristics of walking.     

Dynamics of physical performance during long-duration space flight (first results of "Countermeasure" experiment)

The efficacy of countermeasure exercise for diminishing disturbances induced by microgravity in motor system and its visceral supply during different stages of long-duration flight was evaluated. The results of both bicycle and locomotor testing indicate that physical fitness of cosmonaut does not become worse in the course of the long-duration flight. On the contrary, the lowest fitness was recorded at the first stage of mission, just after one month of flight. The "dead period" at the beginning of space flight seems to be a manifestation of the acute decrease in physical condition on transition from 1 G to microgravity, when none of the regular countermeasure regimes is sufficiently effective and acute increase of volume and intensity of training is impossible under the conditions of space flight.     

Plasma hormone levels in human subject during stress loads in microgravity and at readaptation to Earth's gravity

In great part of the investigations of endocrine system functions in astronauts during space flights the plasma levels of hormones and metabolites were determined only in resting conditions, usually from one blood sample collection. Such levels reflected the psychical and physical state and new hormonal homeostasis of organism at the time of blood collection, however, the functional capacity of neuroendocrine system to respond to various stress stimuli during space flight remained unknown. The aim of present investigations was to study dynamic changes of hormone levels during the stress and metabolic loads (insulin induced hypoglycemia, physical exercise and oral glucose tolerance test) at the exposure of human subject to microgravity on the space station MIR. The responses of sympatico-adrenomedullary system to these stress and workloads were presented by Kvetnansky et al.     

Evaluation of psychological effects due to bed rest

The psychological condition of astronauts is an important factor for ensuring mission success in limited space. Head-down tilting bed rest is a well-accepted method by which to simulate an acute stage of human adaptation to the weightless state in space flight. In our previous studies, the enhancement of depressive and neurotic levels occurred during a 20-day horizontal bed rest. In this study, we attempted to examine the depressive and neurotic levels, the mood status, and behavioral tendency of the subjects and to analyze the changes of 24-hour urinary excretion of 17-hydroxycorticosteroid-glucronides (17-OHCS) for an indicator of changes in the endocrine system due to physical and psychological stress during a 20-day 6-degrees head-down tilting bed rest (BR).     

Contemporary conception of anti-G protection of cosmonauts in flights aboard "Soyuz" space vehicles

To ensure safety of cosmonauts impacted by +Gx loads during insertion into orbit of a Soyuz-type space vehicle, it is critical to conduct appropriate medical selection of candidates to space flights, to give them proper complete physical and specialized centrifuge training, and to make it sure that at the moment of actual injection the cosmonaut's posture is optimal relative to the g-vector and that the body is tight fitting the custom-molded couch. No AGS is needed. For the purposes of protection of cosmonauts descending in the Soyuz vehicles, vital are countermeasures applied in the course of flight, water-salt supplements on the descent day, and the optimal posture, an anti-g suit, and a custom-molded couch with an additional body-restraint system and dampers used on the phase of reentry.     

Collision avoidance in commercial aircraft Free Flight via neural networks and non-linear programming

In recent years there has been a great effort to convert the existing Air Traffic Control system into a novel system known as Free Flight. Free Flight is based on the concept that increasing international airspace capacity will grant more freedom to individual pilots during the enroute flight phase, thereby giving them the opportunity to alter flight paths in real time. Under the current system, pilots must request, then receive permission from air traffic controllers to alter flight paths. Understandably the new system allows pilots to gain the upper hand in air traffic. At the same time, however, this freedom increase pilot responsibility. Pilots face a new challenge in avoiding the traffic shares congested air space. In order to ensure safety, an accurate system, able to predict and prevent conflict among aircraft is essential. There are certain flight maneuvers that exist in order to prevent flight disturbances or collision and these are graded in the following categories: vertical, lateral and airspeed. This work focuses on airspeed maneuvers and tries to introduce a new idea for the control of Free Flight, in three dimensions, using neural networks trained with examples prepared through non-linear programming.     

Comparative analysis of preventive efficacy of different modes of locomotor training in space flight

According to the results of the experiment performed on board the International Space Station with participation of 15 Russian cosmonauts, comparative analysis of efficacy of two models of preventive measures used by the Russian members of long-term space missions is carried out: intense interval training in the aerobic–anaerobic power zone (recommended model) and continuous low-intensity exercises in the aerobic power zone of muscle activity energy supply. Interval training in space flight provided the maintenance of the level of physical performance close to the pre-flight level as indicated by the maximum running speed, physiological value of work, and the lactate level after performing the standard load. We describe putative mechanisms of counteraction to adaptive rearrangement of the propulsion system in zero gravity and expand understanding of the laws governing human body’s interaction with Earth’s gravitational field. The research results presented in this paper show the high preventive efficacy of interval training compared with regular aerobic training, which is very important now in the time of searching for means and methods of prevention of hypogravitational alterations during interplanetary missions.     

Physiological response of pilots to the load of lower body negative pressure

The Czech Air-Force prepares an introduction of a new generation of aircraft with high maneuvering possibilities. The possibility of making full use of the aircraft flight properties assumes sufficient pilot's +Gz tolerance and also its improvement during the new flight training system. The optimal method to achieve this purpose is the human centrifuge utilization. For the Czech Republic, the building or the renting of a human centrifuge for the pilot's selection is unfortunately very expensive. In our institute we are interested in the analysis of the possibilities of the lower body negative pressure (LBNP) technique for the basic pilot's selection with low level of +Gz tolerance, using the examination of the orthostatic cardiovascular reactions of the pilot's organism.     

Effect of long-term hypergravitation on the skeletal-muscular tissue in rats

The space flight or simulated gravitational unloading lead to the muscle atrophy, slow-to-fast transformation of muscle fibers and myofibrillar damages both in humans and animals (1, 7, 13, 17). This process could be prevented by the exercise training during space flight (1), (partly) by periodic weight support during unloading (13). It has been demonstrated in these studies that there is some level of force production necessary for the maintenance of skeletal muscle properties. It is known that adaptation to the physical training frequently induces augmentation in cross-sectional area (CSA) of muscle fibers (MF), transformation of fibers, augmentation of mitochondrial volume density, and increase in absolute volume of myofibrillas. Numerous observations suggest importance of gravitational loading in regulating muscle mass. The centrifuging is believed to be useful for preventing muscle functional and structural losses under microgravity. But there are few studies designed to investigate effect of artificial gravity on the skeletal musculature (2, 7). Our objective was to investigate structural adaptation in slow-twitch soleus muscle (percentage of connective tissue and central nuclei, fiber size, myosin heavy chain isotope, myofibrillar proteins and mitochondria volume density) after 19 and 33 days of hypergravity.     

Physical training in patients with chronic heart failure: An elaboration of the statements from the Committee on Cardiac Rehabilitation of the Netherlands Society of Cardiology and the Netherlands Heart Foundation and review of studies on physical training in chronic heart failure

Chronic heart failure (CHF) can be defined as a complex of symptoms and signs caused by cardiac dysfunction. Dyspnoea on exertion, fatigue, reduced exercise tolerance and fluid retention are hallmarks of the syndrome.Reduced peripheral blood flow, endothelial dysfunction, alterations in skeletal muscle structure and function, an increased activity of the muscle ergoreflex, as well as autonomic and neurohormonal activation reduce exercise performance, ultimately leading to physical deconditioning in CHF patients.The beneficial effects of physical training for CHF patients are increasingly acknowledged. Based on European and American guidelines on physical training in CHF, results from controlled randomised trials (summarised in this paper) and expert opinions, the Dutch Committee on Cardiac Rehabilitation has formulated statements on physical training in CHF.In addition, recommendations implementing physical training programmes in CHF patients are given. The selection criteria, contraindications and methods, and duration of a physical training programme in heart failure are discussed. Concomitant with the training programme, a multidisciplinary intervention programme is needed to stimulate patients to adopt and maintain an active and healthy lifestyle.     

Estimation and prediction of functional changes in organisms in space flight

The article is devoted to theoretical and applied problems of estimation of the organism functional state and a level of health. Transitive states between health and illness, between norm and a pathology, so-called prenosological states are considered. The level of health is determined by adaptable opportunities of an organism, a degree of regulatory systems tension and their functional reserve. As the basic methodical approach to an estimation of a degree of regulatory systems tension the method of heart variability analysis is described. The applied aspect of a considered problem is submitted by results of the researches which have been carried out in conditions of space flight. Changes of organism functional state at different stages of adaptation to conditions of long weightlessness are described. The mathematical model of functional states is submitted. Four types of the vegetative regulation, differing on the adaptive reactions in conditions of space flight are allocated. Results of researches of crew members of the International space station are submitted.     

Analysis of possible causes of activation of gastric and the pancreatic excretory and incretory function after completion of space flight at the international space station

A comparative analysis of the excretory and incretory activity of the stomach and pancreas in astronauts soon after completion of space flights of various durations was performed. An increase in the fasting activity of gastric and pancreatic enzymes and hormones (insulin and C-peptide) in blood, reflecting the increased excretory and incretory activity of organs of the gastroduodenal region developing in microgravity, was demonstrated. The absence of subjects infected with Helicobacter pylori in the space flight crew excluded the involvement of this microorganism in the mechanism underlying the increase in the gastric secretory activity. The absence of correlation between the increase in the secretory activity of organs of the gastroduodenal region and the duration of the space flight allowed us to rule out the hypokinetic mechanism, which is associated with the duration of exposure to microgravity. It was concluded that the main mechanism underlying the changes in the functional state of the digestive system in space flight may be determined by the rearrangement of the venous hemodynamics of organs of the abdominal cavity, unrelated to the duration of exposure to microgravity. It was shown that, after completion of space flights and in ground-based experiments simulating the hemodynamic rearrangement occurring in microgravity, the increase in the basal excretory activity of gastroduodenal organs was not caused by gastrin secretion and occurred simultaneously with an increase in the secretion of insulin, which is considered as a putative hormonal component of the hemodynamic mechanism.     

The problem of optimization of the physical state of school students by means of physical education

The study of the influence of different training regimens on the individual components of the physical state of 7- to 17-year-old school students of different morphofunctional types was carried out. A complex of methods for determining the level of physical development, motor fitness, the muscular capacity for work, the state of the cardiovascular system, and child and adolescent morbidity was used. The study showed the absence of a universal index capable of characterizing the “physical state” on the whole, the measurement of which would make it possible to judge unambiguously the effectiveness of the training process. None of the motor regimens used ensured complete optimization of all the components of the physical state and a decrease in the students’ morbidity. In the course of the experiment, there were many cases in which a training regimen aimed at improving the autonomic regulation of the heart exerted little effect on the total morbidity, a considerable increase in aerobic capacity (as evidenced by the PWC ₁₇₀ test) was not accompanied by an increased level of overall fitness, etc. It was shown that, to optimize different aspects of the physical state of age-matched students with the same constitutional type, it is necessary to use motor activity regimens that differ in their physiological action.     

Impact of microgravity on radiobiological processes and efficiency of DNA repair

To study the influence of microgravity on radiobiological processes in space, space experiments have been performed, using an on-board 1×g reference centrifuge as in-flight control. The trajectory of individual heavy ions was localized in relation to the biological systems by use of the Biostack concept, or an additional high dose of radiation was applied either before the mission or during the mission from an on-board radiation source. In embryonic systems, such as early developmental stages of Drosophila melanogaster and Carausius morosus, the occurrence of chromosomal translocations and larval malformations was dramatically increased in response to microgravity and radiation. It has been hypothesized that these synergistic effects might be caused by an interference of microgravity with DNA repair processes. However, recent studies on bacteria, yeast cells and human fibroblasts suggest that a disturbance of cellular repair processes in the microgravity environment might not be a complete explanation for the reported synergism of radiation and microgravity. As an alternative explanation, an impact of microgravity on signal transduction, on the metabolic/physiological state or on the chromatin structure at the cellular level, or modification of self-assembly, intercellular communication, cell migration, pattern formation or differentiation at the tissue and organ level should be considered.     

Mice in Bion-M 1 Space Mission: Training and Selection

After a 16-year hiatus, Russia has resumed its program of biomedical research in space, with the successful 30-day flight of the Bion-M 1 biosatellite (April 19–May 19, 2013). The principal species for biomedical research in this project was the mouse. This paper presents an overview of the scientific goals, the experimental design and the mouse training/selection program. The aim of mice experiments in the Bion-M 1 project was to elucidate cellular and molecular mechanisms, underlying the adaptation of key physiological systems to long-term exposure in microgravity. The studies with mice combined in vivo measurements, both in flight and post-flight (including continuous blood pressure measurement), with extensive in vitro studies carried out shortly after return of the mice and in the end of recovery study. Male C57/BL6 mice group housed in space habitats were flown aboard the Bion-M 1 biosatellite, or remained on ground in the control experiment that replicated environmental and housing conditions in the spacecraft. Vivarium control groups were used to account for housing effects and possible seasonal differences. Mice training included the co-adaptation in housing groups and mice adaptation to paste food diet. The measures taken to co-adapt aggressive male mice in housing groups and the peculiarities of “space” paste food are described. The training program for mice designated for in vivo studies was broader and included behavioral/functional test battery and continuous behavioral measurements in the home-cage. The results of the preliminary tests were used for the selection of homogenous groups. After the flight, mice were in good condition for biomedical studies and displayed signs of pronounced disadaptation to Earth''s gravity. The outcomes of the training program for the mice welfare are discussed. We conclude that our training program was effective and that male mice can be successfully employed in space biomedical research.     

Permanent depression of plasma cGMP during long-term space flight

The purpose of this study was to investigate plasma concentrations of cyclic guanosine monophosphate (cGMP) and atrial natriuretic peptide (ANP) during and after real and simulated space flight. Venous blood was obtained 3 min after the beginning and 2 min after the lower body negative pressure maneuver in two cosmonauts preflight (supine), inflight, and postflight (supine) and in five other subjects before, at the end, and 4 days after a 5-day head-down tilt (-6 degrees) bed rest. In cosmonaut 1 (10 days in space), plasma cGMP fell from preflight 4.3 to 1.4 nM on flight day 6, and was 3.0 nM on the fourth day after landing. In cosmonaut 2 (438 days in space), it fell from preflight 4.9 to 0.5 nM on on flight day 3, and stayed <0.1 nM with 5, 9, and 14 months in space, as well as on the fourth day after landing. Three months after the flight his plasma cGMP was back to normal (6.3 nM). Cosmonaut 2 also displayed relatively low inflight ANP values but returned to preflight level immediately after landing. In a ground-based simulation on five other persons, supine plasma cGMP was reduced by an average of 30% within 5 days of 6 degrees head-down tilt bed rest. The data consistently demonstrate lowered plasma cGMP with real and simulated weightlessness, and a complete disappearance of cGMP from plasma during, and shortly after long-duration space flight.     

Recording of blood pressure,heart rate and aortic nerve activity during parabolic flight in the rat via radio-telemetry

Exposure to microgravity induces cardiovascular deconditioning characterized by orthostatic hypotension when astronauts return to the earth. In order to understand the mechanism of cardiovascular deconditioning, it is necessary to clarify the changes in hemodynamics and the cardiovascular regulation system over the period of space flight. The telemetry system applied to freely moving animals will be a useful and appropriate technique for this kind of long term study of the cardiovascular system in the conscious animal during space flight. The purpose of the present study is twofold: firstly, to observe the detailed changes of arterial pressure and heart rate (HR) during microgravity elicited by the parabolic flight in order to study the acute effect of microgravity exposure on the cardiovascular system; and secondly, to test the feasibility of the telemetry system for recording blood pressure, HR and autonomic nervous activities continuously during space flight.