[Prognostication of man's health status in response to gravity-induced blood shifts based on continuous noninvasive measurement of arterial blood pressure using the Pen'iaz method]. / Prognozirovanie sostoianiia cheloveka v usloviiakh gravitatsionnogo pereraspredeleniia krovi na osnove nepreryvnogo neinvazivnogo izmereniia arterial'nogo davleniia po metodu Pen'iaza.

Exposure to +Gz acceleration, orthostatic tilt tests and LBNP tests causes distinct blood shifts and deterioration of cerebral circulation. In this case syncope episodes may be prevented by continuous monitoring of circulation parameters, specifically arterial pressure (AP). Our investigations have shown that continuous AP measurement by the Penjaz noninvasive technique may help earlier prediction of the health status in response to gravity-induced blood shifts. In this situation the development of a pre-collapse state is preceded by an emergence of distinct AP waves of the second-third order accompanied by a critical drop of pulse pressure. It is concluded that continuous AP measurement in the finger according to the Penjaz noninvasive technique holds promise as a medical monitoring method in a altered gravitational field.

[Tolerance of functional and exercise tests during 1-year antiorthostatic hypokinesia]. / Perenosimos't obsleduemymi funktsiona'lno-nagruzochnykh prob v usloviiakh godovoi antiortostaticheskoi gipokinezii.

During 370 days 9 healthy young volunteers were exposed to antiorthostatic hypokinesia. Group A consisting of 4 subjects performed exercises similar to those regularly made by Mir crewmembers and Group B consisting of 5 subjects did not exercise for 120 days and then performed experimental exercise regimens. It was demonstrated that the health status of men long exposed to head-down tilting can be controlled with the aid of various countermeasures. As a result of the exposure, orthostatic and exercise tolerance diminished. In view of the fact that the changes observed were more pronounced in the Group B subjects, it can be concluded that the countermeasures used were more effective in Group A subjects.

[Effect of long-term hypokinesia on cardiac/bioelectric activity in healthy men]. / Vliianie dlitel'noi gipokinezii na bioélektricheskuiu aktivnost' serdtsa zdorovykh muzhchin.

Bioelectric activity of the heart was measured in 39 healthy men, aged 25 to 45 years, during their exposure to head-down tilt. The first experimental study which continued for 182 days (-4.5 degrees) was performed on 18 test subjects, and the second study which lasted for 120 days (-4.5 degrees) on 21 test subjects. Both studies included controls (15 subjects) and subjects who exercised during head-down tilt (16 subjects). In addition, the second study also included 4 test subjects who took drugs to modify metabolic shifts and 4 test subjects who were in the drugs + exercise regiment. Prolonged hypokinesia led to a heart rate increase, A-V conductance decrease, and repolarization phase (T-wave) changes. Except for heart rate variations, these changes developed beginning with the first weeks of exposure, plateaued during 1.5 to 2 months and then varied in a sinusoidal manner, coinciding with similar changes in blood neurotransmitters and electrolytes. T-wave changes correlated well with K, Mg and Ca variations in blood. Exercises performed during head-down tilt decreased significantly (1.5-2 times) the level of T-depression and accelerated the restoration of ECG parameters during readaptation. Corinfar taken for two weeks had a noticeably beneficial effect on electrophysiological processes of the heart. The above electrophysiological changes that developed in healthy men during prolonged hypokinesia were of functional, reversible character and disappeared within the 2-month recovery period.

[Some physiological effects caused by 30 days of bed rest in different body positions]. / Nekotorye fiziologicheskie effekty, obuslovlennye 30-sutochnym postel'nym rezhimom s razlichnym polozheniem tela.

Eighteen male test subjects were exposed to a 30-day bed rest with the foot end of the bed tilted at +6 degrees, -2 degrees or -6 degrees. Control subjects were allowed a normal mode of life during the same period of time. Hypokinesia was shown to play the leading role in the genesis of most changes, since control subjects displayed no changes. It was concluded that head-down tilt simulated changes occurring during adaptation to weightlessness better than recumbency or head-up tilt.

[Blood circulation under physical load in the crew members of the 1st Saliut-6 base expedition]. / Krovoobrashchenie pri fizicheskoi nagruzke u chlenov ékipazha pervoi osnovnoi ékspeditsii "Saliut-6".

During the 96-day flight aboard the Salyut-6 station the crewmembers showed a satisfactory response to bicycle ergometry of moderate load. However, cardiovascular regulation during exercise declined, particularly by the end of the first and the beginning of the second month. This was mainly associated with deconditioning due to an inadequate work load. Its increase helped to restore an initial level of circulation during exercise by the end of the mission.

[Use of electrical muscle stimulation for the prevention of neuormuscular disorders during 45 days' antiorthostatic hypokinesia]. / Primenenie élektrostimuliatsii myshts dlia profilaktiki neiromyshechnykh rasstroistv pri 45-sutochnoi antiortostaticheskoi gipokinezii.

Healthy test subjects exposed to a 45-day head-down tilting (- 6.5 degrees) showed a decline of the tone and strength of certain muscle groups, a decrease of leg circumference, a deterioration of the walking pattern, and a reduction of exercise tolerance (provocative tests with bicycle ergometry pedaling at a moderate and maximum rate). Electrostimulation of muscles applied by the Tonus-2 equipment for 30 min twice a day, 6 days a week helped to reduce the level of hypokinesia-induced disorders.

[Regulation of the vertical posture after flights on the Saliut-4 orbital station]. / Reguliatsiia vertikal'noi pozy posle poletov na orbital'noi stantsii "Saliut-4".

Stabilographic examinations of the crewmembers of the orbital station Salyut-4 demonstrated that one of the most characteristic manifestations of posture-tonic deconditioning induced by a prolonged exposure to weightlessness was an emergence of high-frequency oscillations (with a cycle of 0.1--0.15 sec) of the common center of body gravity, the fraction of the oscillations decreasing during the first weeks of the postflight period. After flight all the crewmembers showed signs of postural hypotension: an increase in the cardiac rhythm and a decrease in the pulse arterial pressure.

[Effect of an increased level of hydration on human tolerance to orthostatism and the action of LBNP]. / Vliianie povyshennogo urovnia gidratsii na ustoichovost' cheloveka k ortostazu i vozdeistviiu ODNT.

Intake of fluid, water-salt solutions, water and sodium chloride resulted in hyperhydration, the level and duration of which varied with respect to the pattern and composition of the ingredients consumed. As applied to real space flights, fractional consumption of water and sodium chloride proved most promising. This regimen yielded a distinct and prolonged hyperhydration and incrased orthostatic and LBNP tolerance of the test subjects.

[Effect of a course of electric stimulation of the muscles on human orthostatic resistance]. / Vliianie kursa élektrostimuliatsii myshts na ortostaticheskuiu ustoichivost' cheloveka

The effect of muscle electrostimulation on orthostatic tolerance was assessed in two experimental runs. In the first run 6 healthy test subjects took part and in the second run 12 test subjects (three groups of 4 persons each) participated. In the first run electrostimulation applied for 1 month (30 min a day) on an out-of-clinic basis affected favorably orthostatic tolerance. In the second run electrostimulation applied during a 45-day bed rest experiment (30 min twice a day) yielded different results. The 1st group subjects who were stimulated with 20 electrodes showed a favorable effect. The 2nd group subjects who were stimulated with 12 electrodes exhibited a limited effect. The 3rd group subjects (controls) who were not stimulated during bed rest displayed a marked decrease of orthostatic tolerance.

[Reactions of the cardio-respiratory system of cosmonauts to dosed physical loads following 30- and 63-day flights in orbital station "Salyut-4"]. / Reaktsii kardio-respiratornoi sistemy na dozirovannuiu fizicheskuiu nagruzku u kosmonavtov posle 30- i 63-sutochnykh poletov na orbital'boi stantsii "Saliut-4"

Cardiorespiratory responses of Salyut-4 crewmembers to exercises of 600 kgm/min performed for 7 min on a bicycle ergometer in the supine position were studied. It was found that the 30- and 63-day flights induced a certain decrease in the body response which included a less economic functioning of the cardiorespiratory system during exercise. The degree of postflight changes of the 30- and 63-day crewmembers was similar. At the same time the cardiorespiratory system of the 63-day crewmembers returned to the preflight level more rapidly than that of the 30-day cosmonauts.

[Reactions of the human cardiovascular system to orthostasis following high altitude adaptation]. / Reaktsiia serdechno-sosudistoi sistemy cheloveka na ortostaz posle adaptatsii k vysokogor'iu

Orthostatic tolerance of 18 healthy test subjects (three groups of 6 persons each) who were exposed to an altitude of 2200 m for 12 days and 3200 m for 12 days was studied. The first group subjects remained in bed with minimized motor activity. The second group test subjects rested in bed and twice a day performed physical exercises with energy expenditures of 300 kcal/day. The third group subjects led a normal mode of life. The studies demonstrated that a prolonged restriction of motor activity and a decrease in the blood hydrostatic pressure of healthy test subjects in highlands resulted in their diminished orthostatic tolerance. Physical exercises proved ineffective in that case. The subjects who led a normal mode of life showed increased cardiovascular reactions to orthostatic tests.