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Biomedical subjects

E A Kovalenko

Publications and source records attributed to E A Kovalenko.

At least 19 recordsLinked to original sources
PubMed1999

New molecular complexes of heterocyclic bis-adducts with bacterial lectins: synthesis and structure-activity relationship studies.

A strongly antitumour effect has been discovered for lectins of Bacillus bacteria [Bacillus subtilis 668(1 + 2)IMV, Bacillus polymyxa 102(1 + 2) KGU] and for their molecular complexes with some heterocyclic bis-adducts of unsubstituted benzimidazole and 6-methyluracile for the first time. These were tested on the tumours: Lymphosarcoma Plissa, Sarcoma 45, Carcinosarcoma Yokera 256. A new convenient method for the preparation of the heterocyclic bisadducts of imidazole, benzimidazole, uraciles with 1,1,1-trifluoro-2-bromo-2-chloroethane is described. The reactions are catalysed by the 18-crown-6-complex.

Amino Acids↗
PubMed1999

[The relation between the level of antibodies to the glycosaminoglycans of the cartilage in patients with osteoarthritis and the efficacy of treatment with chondroprotectors].

AIM: To improve the efficacy of osteoarthrosis (AO) treatment by chondroprotectors by defining individual indications for their use, based on the initial level of antibodies to cartilaginous glycosaminoglycans (GAG) in the blood serum. MATERIALS AND METHODS: Anti-GAG were detected by indirect solid-phase enzyme immunoassay. The antigen was a sulfated GAG preparation GAG-polysulfate (arteparon) manufactured by Luitpold-Werk (Germany). Sera of 110 OA patients were tested. Fifty of them were treated by rumalon, 20 with arteparon, and protocols of 40 patients included no chondroprotectors. RESULTS: The highest levels of anti-GAG were found in OA patients with multiple involvement of the joints, rapidly progressing disease, and secondary synovitis. The titer of antibodies increases with disease duration and in patients with the roentgenological stage of OA, reaching the maximum by 10-15 years of disease or by stage III. Efficacy of chondroprotectors was lower at lower levels of antibodies to cartilaginous GAG. CONCLUSION: Chondroprotector therapy of patients with initially high levels of antibodies to GAG is unadvisable, for it can lead to exacerbations, specifically, to secondary synovitis.

Adult↗
PubMed1995

[Several indicators of tissue oxygen during modeling of extravehicular activity of man].

Investigations of tissue oxygen indices during simulation of extravehicular activity (EVA) of cosmonauts demonstrated that breathing pure oxygen at approximately 280 mmHg elevates oxygen tension in capillary blood, and capillary-tissue gradient during physical work. Physical work alone stimulates tissue oxygenation due to, apparently, intensification of the processes of oxidative phosphorylation. The observed shifts in oxygen status reverse significantly within the first 5 min after completion of the experiment.

Adult↗
PubMed1993

[Pulsed hypoxia in the treatment of obstructive lung diseases].

A new approach to the treatment of chronic nonspecific pulmonary diseases is proposed: helium-oxygen therapy combined with repeated interrupted hypoxic stimuli. Helium inclusion into hypoxic gas mixture leads to reduced air density. Gas mixture containing 10-15% of oxygen is more effective at the level of alveolocapillary membrane. When conducted in normal atmospheric pressure, the method involved no complications and produced positive responses in coronary heart disease, hypertension, alimentary diseases. The mixture of helium with oxygen (85-90% of helium, 10-15% oxygen) in combination with impulse normobaric hypoxia has been tried in 25 chronics with obstructive bronchitis and bronchial asthma. The results were indicative of the treatment efficacy: bronchial permeability improved in 67% of the cases, forced vital capacity of the lungs increased, inspiratory reserve volume grew, dyspnea and cough diminished, sputum discharge improved, general tonicity and performance status changed positively. Six-month follow-up evidenced positive shifts too.

Adult↗
PubMed1992

[Oxygen tension and water-soluble products of lipid peroxidation in blood of volunteers in hypobaric hyperoxia].

Oxygen tension in the arterial blood with transcutaneous method (tcPO2) and TBA-active products of venous blood plasma were measured during simulation of extravehicular activity. There was a parallel increase of tcPO2 and the level of TBA-active products upon introduction of hypobaric hyperoxia factor. Detrimental action of lipid peroxidation products on erythrocyte membranes can be one of the factors of anemia during space flight.

Adult↗
PubMed1986

Oxygen regimen in the human peripheral tissue during space flights.

A survey of the results of the experiment "Oxygen," carried out within the scope of the INTER-KOSMOS program in members of the permanent crews and of international visiting expeditions to the Soviet orbital station Salyut-6, is given. During the 7-day space flights of the international visiting expeditions a significant decrease in pO2ic by 3.28 kPa was observed. Local oxygen utilization reduced significantly by 0.44 kPa. During hyperventilation testing after return to earth a statistically significant decrease in the peak value by 1.39 kPa was noted. In the long-term crews of the orbital station Salyut-6 the highest decrease in pO2ic of 3.8 kPa and the absolutely lowest value of 3.4 -/+ 0.5 kPa during space flight were observed. The decrease in local oxygen utilization during the flight of 0.8 kPa/min was greater than that of the visiting crews. The results indicate the importance of investigating the dynamics of the oxygen regimen for medical control of the crew members both during the space flight and during the readaptation phase after return to earth.

Adaptation, Physiological↗
PubMed1986

[Role of the gas composition of intraocular fluid in the regulation of intraocular circulation].

The recovery velocity of the acido-alkaline state of the intraocular fluid depended upon the ocular hemodynamics in the rabbit intraocular chamber. Oppressive action of hyperoxia and substitute hypocapnia on intraocular blood circulation was revealed. The RQ reduction described in some eye diseases and after intraocular operations can be connected with changes in gaseous composition of the intraocular fluid.

Animals↗
PubMed1981

Measurement of the partial oxygen pressure and oxygen utilization in the skin of cosmonauts aboard Salyut 6.

The oxygen tension (PO2) in the dorsal skin surface of the forearm was studied during the stay of cosmonauts on board Salyut 6. Between the fourth and fifth day of stay on the orbital station a considerable reduction of the PO2 level was observed. The oxygen utilization values were also reduced. In the early postflight period the low PO2 level persisted with gradual normalization.

Aerospace Medicine↗
PubMed1980

[Characteristics of the formation of human cardiovascular system reactions to acute hypoxia].

"Emergency" adaptation of the cardiovascular system of a healthy person to acute hypoxia produced by inspiration of a gas mixture containing 11% oxygen was accomplished in two ways: (a) with prevalence of the cardiac component, increase in the cardiac and systolic indices and end-diastolic volume in unaltered ejection fraction and diminished general vascular tonus; (b) with prevalence of the vascular component, decrease in the cardiac and systolic indices, end-diastolic volume, and muscular and skin blood flow and increase in peripheral resistance. After 10 days of training for hypoxia in a pressure chamber the reaction of the cardiorespiratory system to the hypoxia test was less pronounced but its trend was maintained.

Acute Disease↗
PubMed1976

Space flight effect upon the bioenergetics of the skeletal muscles in rats.

Studies of tissue bioenergetics are very important to gain insight into the effects of weightlessness on the animal and human body. A reduction of the muscular load in zero gravity should affect reactions of biological oxidation because their pattern and level are related to energy requirements of the body. After the 22-day flight of the Cosmos 605 biosatellite tissue respiration and oxidative phosphorylation (P/O coefficient) in skeletal muscles of rats was investigated. The investigations showed that on the 2nd post-flight day oxidation assimilation by the muscle tissue was reduced compared with the control. In addition, the intensity of phosphorylation which determines the rate of ATP formation was decreased. These changes may reduce significantly the energy potential of the muscle cell and seem to form the basis for the functional inadequacy of skeletal muscles which can be found in men during the first post-flight days. At later stages (the 26th post-flight day) oxygen consumption and phosphorylation rate increased and reached the control level. Therefore, readaptation to the earth gravity is followed by adaptive changes in the processes responsible for the accumulation and utilization of the energy of biological oxidation.

Adenosine Triphosphate↗
PubMed1976

[Influence of prolonged hypokinesia on the water and fat composition of the human body].

A study was made of a combined action of prolonged hypokinesia (period - up to 30-49 days) and of different position of persons under trial (healthy men) to the gravitation vector on the body composition. Changes in total water content in the organism largely depended not on the limited mobility, but on the body position in space. In antiorthostatic position of persons under trial water "elimination" occurred chiefly during the first several days. The "lean mass of the body" decreased as a result of prolonged hypokinesia, and water content fell in it; but water content was rapidly restored with the restoration of the motor activity.

Body Water↗