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Biomedical subjects

E A Kovalenko

Publications and source records attributed to E A Kovalenko.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Biological activity of bacterial lectins and their molecular complexes with heterocyclic bis-adducts.

A new convenient method for the preparation of heterocyclic bis-adducts: of imidazole, benzimidazole, uracile with 1,1,1-trifluoro-2-bromo-2-chloroethane is described. The reactions are catalysed by the 18-crown-6-complex. The critical toxicity and antitumour activity of saprophytic strains Bacillus genus (B. subtilis 668 IMV and B. polymyxa 102 KSU) extracellular lectins were studies. It was discovered that these substances apply to a few toxic preparations and have a expression antitumour action on the tumours: Walker carcinosarcoma 256, Pliss' lymphosarcoma and Sarcoma 45. The new molecular complexes were created with bacterial lectins and the same heterocyclic-bis-adducts of unsubstituted benzimidazole and 6-methyluracile. A strongly antitumour effect of these complexes has been discovered: of growth relaxation of Pliss' lymphosarcoma tumour mass was 62.5-82.01%.

Animals↗
PubMedDate not supplied

[Detection of furadan in biological fluids].

Optimal conditions have been determined for furadan isolation from biological fluids by means of the mixture of solvents ethyl acetate-acetone in volume 1:1. Possible purification of the compound from coextractive substances of biomaterial on the column with silica gel L 100/160 mcm is demonstrated. IR-spectrophotometric methods and high performace liquid chromatography with a detector of photodiode matrix are proposed for identification and quantitation of furadan in blood and urine specimens.

Carbofuran↗
PubMedDate not supplied

[Various physico-chemical properties of the amylolytic complex from Bacillus mesentericus].

Some physico-chemical properties of the Bacillus mesentericus amylolytic complex were studied, and optimal conditions of starch hydrolysis (pH 7.5-8.0; 45 degrees C) were found. The half-life of amylases at 50 degrees was 75 min. The heat stability of the enzymes increased in the presence of Ca2+ ions. Amylase was stable at pH 7-9 and readily inactivated at pH below 6.0. By physical and chemical characteristics the complex was close to analogous preparations from Bacillus alkalophilic strains. Isoelectrofocusing revealed that the complex consisted at least of two amylolytic enzymes.

Amylases↗
PubMedDate not supplied

[Pathophysiology of prolonged hypokinesia].

Hypokinesia is an important problem in modern medicine. In the pathogenetic effect of prolonged hypokinesia the main etiological factor is diminished motor activity; of major importance are disorders in the energy and plastic metabolism which affect the muscle system; the contributing factors are cardiovascular deconditioning and orthostatic intolerance. This is attributed to a decreased oxygen supply and eliminated hydrostatic influences during a prolonged recumbency. Blood redistribution in the vascular bed is related to the Gauer-Henry reflex and subsequent changes in the fluid-electrolyte balance. Decreased load on the bone system induces changes in the protein-phosphate-calcium metabolism, diminished bone density and increased calcium content in the blood and urine. Changes in the calcium metabolism are systemic. The activity of the higher nervous system and reflex functions is lowered. Changes in the function of the autonomic nervous system which include a noticeable decline of its adaptive-trophic role as a result of the decrease of afferent and efferent impulsation are of great importance. Changes in the hormonal function involve a peculiar stress-reaction which develops at an early stage of hypokinesia as a response to an unusual situation. Prolonged hypokinesia may result in a disturbed function of the pituitary-adrenal system. It is assumed that prolonged hypokinesia may induce a specific disease of hypokinesia during which man cannot lead a normal mode of life and work.

Aldosterone↗
PubMedDate not supplied

[Acid-base equilibrium, blood gases and glycolysis during modeling of the factors of extravehicular activities].

The effect of factors simulating extravehicular activities (lower barometric pressure, 100% oxygen breathing, physical load on the upper body, head-down body position) on blood gas composition, acid-base equilibrium, and glycolysis end-products was investigated in 17 test subjects. It was found that 5-hour exposure did not change physiological responses to test workloads, when compared to the baseline studies. In the simulation studies, changes in acid-base equilibrium of venous blood were more significant than those of mixed capillary blood. The variations of the parameters under study reflected primarily the effect of hyperoxia on metabolic processes. The head-down position affected the level of variations in gas composition and acid-base equilibrium of venous blood. These changes were transient and rapidly returned to the norm after termination of the exposure.

Acid-Base Equilibrium↗
PubMedDate not supplied

[The mitogenic properties of Fusarium graminearum and Rhodococcus erythropolis enzymes].

Blast transformation of peripheral blood lymphocytes in healthy people is studied by enzymes of the microbic origin possessing the lectin activity. Galactose oxidase of Fusarium graminearum IMV-F-1060 is shown to be mitogenically active with respect to the lymphocytes in the culture in vitro and may be one of home sources of lymphocytic mitogens for the laboratory investigations.

Escherichia coli↗
PubMedDate not supplied

[Characteristics of hydrolase biosynthesis in Bacillus mesentericus grown on various media].

The dynamics of the consumption of major carbon and nitrogen sources and the biosynthesis of hydrolytic enzymes were studied in Bacillus mesentericus grown on semisynthetic media. Conditions were chosen that provide the obtaining of the culture liquid with predominantly proteolytic or amylolytic activity. The replacement of maltose with native starch resulted in more intensive accumulation of the biomass and hydrolytic enzymes, and in more rapid (by 3-5 hr) transformation from the logarithmic to the stationary growth phase.

Bacillus↗
PubMedDate not supplied

[Hydrolase biosynthesis by morphological variants of Bacillus mesentericus as dependent on the storage conditions].

A method used to prepare the inoculum (a strain of Bacillus mesentericus, a producer of a complex of hydrolytic enzymes) has been studied for its effect on the activity of proteinases and amylases under submerged cultivation in fermenters. Optimal conditions for the culture storage and inoculum cultivation are developed to obtain standard enzymic preparations.

Bacillus↗
PubMedDate not supplied

[The effect of the cultivation conditions on lectin production by representative bacteria in the genus Bacillus].

Dynamics of the lectin activity accumulation in the culture liquid was studied through the example of certain representatives of spore-forming aerobic bacteria in the process of their growth. The environmental factors (the temperature, pH value, the presence of definite carbohydrates in the medium) were investigated for their effect on the biosynthesis of extracellular lectins by producers. Based on these studies it was possible to establish optimal conditions of cultivation and to obtain the high specific lectin activity of the culture liquid for each strain.

Bacillus↗
PubMedDate not supplied

[Chief methods of modeling the biological effects of weightlessness].

The paper describes basic principles related to weightlessness simulation. In ground-based experiments zero-g is simulated with respect to the conceptual mechanisms of weightlessness effects on the body. The main components of the effects are considered to be elimination of deformations and fluid redistribution. The paper surveys and summarizes different methods of weightlessness simulation. It discusses advantages and disadvantages of water immersion, prolonged bed rest, hypokinesia, suspension in special devices with many degrees of freedom, walking on a treadmill at different angles, etc. The paper describes simulation of accentuated individual effects of zero-g during an exposure to longitudinal acceleration. It presents experimental physiological methods of simulation and symptoms of zero-g effects under normal laboratory conditions. The paper emphasizes inadequate use of some simulation techniques.

Bed Rest↗