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Biomedical subjects

V I Lebedev

Publications and source records attributed to V I Lebedev.

At least 55 records · Page 3Linked to original sources

[A device for the treatment of dislocations and subluxations of the temporomandibular joint].

An extraoral approach to the treatment of dislocations and subluxations of the lower jaw by means of a special outfit holds promise since it has no contraindications, does not cause any complications, fully preserves lower jaw function, shortens the treatment period, and enables surgical interventions to be avoided. The outfit is attached to the patient's head and is only removed overnight. The treatment may last 1.5 to 3 months.

Adolescent↗

[Status of water-electrolyte homeostasis and the systems of hormonal regulation during 237-day space flight].

On mission days 216-219 two crewmembers collected urine and recorded their food and water consumption during three days on end. The cosmonaut-physician withdrew blood samples from the vein and finger. In addition, he made venipuncture to himself and drew blood. Urine and blood samples were frozen and returned to the ground for analysis. In spite of individual variations of each cosmonaut, they all showed a trend for water and sodium retention which was provided by adequate hormonal rearrangement, i. e. increased production of ADH and aldosterone. No disorders in calcium and phosphorus metabolism were seen. Immediately postflight the cosmonauts displayed typical changes in fluid-electrolyte balance and renal function that suggested body dehydration and adjustment to Earth's gravity.

11-Hydroxycorticosteroids↗

[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↗

[The role of medical gymnastics in a swimming pool in the rehabilitation of hypertension patients].

The effect of underwater exercise on the course of essential hypertension was studied using an original radiometric system "Pool" specially devised to measure muscular effort in water. Remote ECG registration promoted setting graded muscular loads varying with myocardial reserve and arterial pressure. The loads proved effective in sanatorium treatment of hypertensive patients.

Adult↗

[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↗

[Changes in the content of bile acids and lipids in human bile during head-down tilt hypokinesia and their correction].

The spectrum of bile acids and bile lipids in men exposed to 120-day head-down tilt was investigated. The test subjects were subdivided in to four groups: group 1-bed rest per se, group 2-bed rest + exercise, group 3-bed rest + drugs normalizing calcium metabolism, and group 4-bed rest + exercise + drugs. It was anticipated that biliary concrements would primarily be formed in group 1 and 2 subjects. They showed a low level of bile acids and a high content of total Ca and cholesterol in the bile, which was more pronounced in the C portion (decrease of the cholate/cholesterol coefficient). Group 2 subjects displayed a modified synthetic function of the liver: prevalence of tauroconjugates in the bile (decrease of the ratio of glucoconjugates to tauroconjugates). Group 3 and 4 subjects showed a faster synthesis of bile acids in the liver and a lower content of total calcium and cholesterol in the bile, the latter being more distinct in group 4 subjects. Positive dynamics of these parameters is a factor responsible for a reduced lithogeny of the bile. However, the test subjects of these groups exhibited hazardous changes that may be responsible for concrement formation. This is indicated by a lower concentration of the lipid complex in the bile, possibly at the expense of a lower content of phospholipids. This emphasizes the necessity of further search for prophylactic procedures aimed at normalizing the synthetic function of the liver under hypokinetic conditions.

Adult↗