[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].

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.

[Tolerance of functional and exercise tests during 1-year antiorthostatic hypokinesia].

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.

[Effect of long-term hypokinesia on cardiac/bioelectric activity in healthy men].

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.

[Some physiological effects caused by 30 days of bed rest in different body positions].

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.

[Blood circulation under physical load in the crew members of the 1st Saliut-6 base expedition].

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.

[Use of electrical muscle stimulation for the prevention of neuormuscular disorders during 45 days' antiorthostatic hypokinesia].

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].

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.

[Effect of an increased level of hydration on human tolerance to orthostatism and the action of LBNP].

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].

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.

[Reactions of the cardio-respiratory system of cosmonauts to dosed physical loads following 30- and 63-day flights in orbital station "Salyut-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.

[Reactions of the human cardiovascular system to orthostasis following high altitude adaptation].

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.