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Biomedical subjects

N E Panferova

Publications and source records attributed to N E Panferova.

At least 19 recordsLinked to original sources
PubMedDate not supplied

[Cardiovascular system during hypokinesia of varying duration and intensity].

The paper gives and compares data on the orthostatic tolerance of man exposed to different hypokinetic conditions of varying duration -- water immersion (10 days), supine position in the chair close to the mean physiological rest posture (7-20 days), bed rest (10-120 days) and altitude chambers (3-70 days). The tolerance to orthostatic tests decreased to a larger extent after experiments in which the motor activity was significantly lowered: water immersion, supine position in the chair and 120-day bed rest; orthostatic tolerance reduced to a lesser extent after altitude chamber experiments. The level of decline of the motor activity was more important than the time of hypokinetic exposure. The most noticeable reduction of adaptive capabilities of the cardiovascular system developed during the first 30 days of bed rest.

Adaptation, Physiological↗
PubMedDate not supplied

[The effect of super-erythematous doses of UV-radiation on the general condition of the human body].

The effect of excessive UV-radiation with 2-4, 5-6, or 7-8 minimal erythematous doses (MED) on man's health condition was investigated, when the irradiated surface area made 20% or 50% of the body surface area. Before and 1 or 3 days after exposure the following parameters were measured: skin state, skin perspiration, body temperature, fluid consumption, diuresis, ECG, PCG, occlusion plethysmography. The observations allowed the conclusion that 5-8 MEDs were threshold doses inducing early intoxication in response to local irradiation (20% of the body surface area) and upper body irradiation (50% of the body surface area). Irradiation with 7-8 MEDs caused noticeable intoxication: fever, headache, increased body temperature (37 degrees C and over), inhibited perspiration, fluid retention, and altered cardiac function.

Body Temperature↗
PubMedDate not supplied

[The duration of the aftereffects of UV-irradiation of man in conditions of UV-insufficiency].

The purpose of the present investigation was to study the aftereffect of UV-B-irradiation applied during 10 or 20 sessions. The biological effect and aftereffect duration of UV-B-irradiation of the upper body of 9 healthy volunteers (residents of the city of Moscow and its suburbs) were evaluated in autumn and winter. During UV-irradiation in the range 220-280, 280-320, or 320-400 nm the flux density was 0.035, 1.75, or 0.65 W/m2, respectively. Group 1 subjects (5 men) were exposed to UV-B-irradiation 10 times (once with 0.5, 0.6, 0.75, 0.9, 1.1, 1.35, 1.65 MED and three times with 2.0 MED) and Group 2 subjects (4 men) were exposed to UV-B-irradiation 20 times (twice with 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 MED and eight times with 2 MED). The sessions were arranged every other day. The exposure produced a beneficial effect on the human body: skin sensitivity decreased, resistance of skin capillaries increased, Ca metabolism normalized, blood 25 (OH) D grew. The trend of responses was similar after 10 and 20 sessions; however, 20 sessions caused a longer-term aftereffect. In relation to space programs, it is concluded that UV-irradiation can be applied on the ground before short-term flights (less than 4 months) and in space during longer-term flights (greater than 4 months).

Calcium↗
PubMedDate not supplied

[Effects of increased doses of ultraviolet radiation on several parameters of human metabolism].

Three experimental series, in which 20 test subjects took part, were carried out to investigate the effect of super-erythemic doses of ultraviolet irradiation on metabolic parameters. It was found that UV irradiation of 12-15% of the skin area led not only to skin changes but also to functional changes in certain organs and systems, which was indicated by variations of metabolic parameters.

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[Prevention of ultraviolet insufficiency after a long stay by humans in an isolation chamber].

The purpose of this study was to investigate biological effects of various regimens of ultraviolet irradiation in order to prevent UV insufficiency in men long kept in an enclosure. The subjects were kept for 60 days under artificial illumination in a Moscow laboratory in winter time. Two different regimens of UV irradiation were used and compared: 20 exposures at a dose of 0.75 MED and 20 exposures at incremental doses from 0.5 to 2 or 3 MED. Before and after 10 and 20 exposures (with medium-range radiation being predominant) the skin state, vitamin and mineral metabolism, and cytotoxicity of natural killers were investigated. The experimental observations allowed the conclusion that prophylaxis of UV insufficiency in men long kept in an enclosure can best be provided by UV irradiation at an incremental dose up to 2 MED. During this exposure skin sensitivity to UV radiation decreased, the content of vitamins D, A, E and that of Ca, P, Cu grew, and cytotoxicity of natural killers lightly increased. UV irradiation at a dose of 0.75 MED proved inadequate and that at a dose of 3 MED induced signs of excessive irradiation.

Dose-Response Relationship, Radiation↗
PubMedDate not supplied

[Measurement of the temperature of deep-seated tissues in healthy men during hypokinesia].

During a head-down tilt (-5 degrees) study, in which 10 healthy male subjects took part, their body temperature variations were investigated. Skin temperature was measured using and electrothermometer with a point sensor-thermistor and core temperature was measured using a radiothermometer at the wavelength 20 cm. The study showed that the distribution profile of core temperature was close to that of skin temperature: the lowest temperatures were characteristic of the limbs and the highest of the chest, stomach and head. During head-down tilt variations in core temperatures were different from those of skin temperature. As a result, the temperature gradient between the skin and core layers increased by bed-rest day 50. In the subjects who regularly exercised during bed rest the gradient grew because their skin temperature fell while in the subjects who did not exercise the gradient increased due to both factors, i.e. skin temperature decrease and core temperature increase.

Abdomen↗
PubMedDate not supplied

[Effect of different doses of ultraviolet radiation on vitamin provision to the human body].

Exposure of healthy adults to prophylactic doses of UV-radiation in the medium- and long wavelength spectrum improved metabolism of vitamins A, E and D and increased their content in the body. UV-irradiation even in prophylactic doses increased ascorbic acid requirements. Excessive UV-irradiation produced an adverse effect on the vitamin content. However, the vitamin concentration in blood was not significantly decreased. This can be explained by the adaptation of the human body to UV-irradiation upon a continuous increase of its dosage.

Ascorbic Acid↗
PubMedDate not supplied

[Prospects for using ultraviolet radiation in protracted space flights].

The data concerning UV-effects on the human body and the environment are reviewed as applied to long-term flights. It is concluded that UV-radiation can be used in long-term space flights in view of its vitamin-forming, desensitizing, bactericidal, and supporting properties to improve the environment and to prevent adverse effects of space flight factors.

Adaptation, Biological↗
PubMedDate not supplied

[Dynamics of changes in the fluids of the extremities in man in different body positions].

Anthropometric measurements and occlusion venous plethysmography were used to investigate fluid inflow and outflow in the limbs of human subjects who kept normal motor activity for 4 hrs, remained in recumbency or were in the head-down position at an angle of -12 degrees and -22 degrees (to simulate effects of zero G). During these exposures diuresis, heart rate and blood pressure according to Korotkoff were also measured. In the horizontal and, to a greater extent, head-down position, when motor activity was diminished, volume blood flow velocity in the limbs decreased, i. e. blood inflow to them became smaller. Arm volume varied insignificantly since inflow and outflow were in balance whereas leg volume decreased because fluid outflow was larger than inflow. In the head-down position the tone of leg veins also declined. Thus the peripheral vascular bed developed a complex of mechanisms that were to prevent volume overload of the central bed. Fluid shifts from the legs to the central bed were made up for by the renal excretion of water in the horizontal and head-down (-12 degrees C) (-22 degrees) produced a stressful effect on compensatory mechanisms which manifested as a greater rise of diastolic pressure and bradycardia. The data obtained indicate an active involvement of the peripheral vascular bed in the adaptation to diminished motor activity in the horizontal and head-down position of human subjects.

Adult↗