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Biomedical subjects

M A Chebotareva

Publications and source records attributed to M A Chebotareva.

9 recordsLinked to original sources
PubMed1995

Comparative investigation of lipid and fatty acid composition of fish gills and mammalian lungs. A model of the membrane lipid component areas.

The lipid and fatty acid composition of gills and lungs were studied in 18 fish species and seven mammalian species. Different relationships among individual phospholipids and different molar ratios between phospholipids and cholesterol (2:1 in fish and 3:1 in mammals) were found. Conformational analysis of the main phospholipid and cholesterol molecules was carried out using a molecular mechanics method. The model of "one unit fragment of the membrane lipid component" accommodates 19 lipid molecules in fish and 42 in mammals. The areas of the molecule projections of the main phospholipids do not differ from each other by more than 2-3%. It may be suggested that the closely packed lipids in membranes of the aerohaematic barrier protect the organism of mammals from the high oxygen content in the environment.

Animals↗
PubMedDate not supplied

[Respiratory organ lipids in fishes and mammals. A model representation of the area of the lipid component].

Studies have been made on lipid composition of the gills in 19 species of fishes and of the lungs in 8 mammalian species. It was shown that the arbitrary "unit fragment" of the lipid component of the respiratory organs in all the investigated animals exhibits similar qualitative composition, but contains different quantity of lipid molecules, i. e. approximately 19 in fishes and 42 in mammals. Theoretical conformational analysis revealed predominant conformations of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin and cholesterol; projections of these molecules on the surface which is parallel to membrane surface were composed. It was shown that projectional areas for the main phospholipid molecules differ only by 2-3%. These data indicate that the surface of a model of the lipid component in the membranes of respiratory organs in mammals is twice larger than in fishes. These differences presumably account for more effective oxygen transfer in mammals.

Animals↗
PubMedDate not supplied

[Brain cholesterol in representatives of different vertebrate classes].

Studies have been made on the cholesterol content of the brain in 73 species of vertebrates. Cholesterol content increases in both aquatic and terrestrial animals in evolutionary row. Significant variations in cholesterol content were noted within the same class. Comparative studies revealed correlation between changes in phospholipids and cholesterol on one hand and various glycolipids on the other. It is suggested that cholesterol content of the brain in vertebrates depends on ecological factors rather than on taxonomic position of animals.

Animals↗
PubMedDate not supplied

[Lipid composition of spinal bone tissue in rabbits of different ages].

Studies have been made on the lipid composition of total lipids, triglycerides and their fatty acids, cholesterol and phospholipids in the vertebral column of young and adult rabbits. It was shown that the content of total lipids and triglycerides increases, whereas that of cholesterol and phospholipids decreases with age. The content of total lipids in the vertebral column is 10 times higher as compared to that in the bones of the extremities. Mid-thoracic part of the vertebral column exhibits higher lipid content than other thoracic parts of the column. Lipid content of the vertebral processes is lower than that of the vertebral bodies. These data indicate lipid specificity and heterogeneity of bone tissue of the vertebral column. The main fatty acids of vertebral triglycerides are presented by those with 14-18 carbon atoms (90%), no acids with 22 atoms were found. Higher content of the linoleic acid (19%) and higher total unsaturation of triglycerides were found in the bone tissue of rabbits in comparison with those of man.

Aging↗
PubMedDate not supplied

[Cholesterol in the brain of cartilaginous and bony fish].

Data are presented on the content of cholesterol in the brain of 23 fish species with different phylogenetic position and ecology. Stable and lower cholesterol content (mean level 10.6 mg/g wet tissue) in the brain of 11 species of Chondrichtyes was shown together with variable and higher (mean level 13 mg/g wet tissue) one in the brain of 12 species of Teleostei. The data obtained are discussed in relation to phylogenetic position of the species investigated and ecological factors (depth and temperature). The ratio of cholesterol to phospholipids in the brain of fishes is lower than that in mammals.

Animals↗
PubMedDate not supplied

[The possible role of fatty acids and their conformation in the realization of the respiratory function and in the adaptations of fish gill membranes and of mammalian lungs].

Fatty acid composition of major phospholipids has been studied in 12 fish and 7 mammalian species. Projections of the fatty acid pairs of these molecules on the plane parallel to the membrane surface have been computed. The projection area of two saturated acids was shown to look like the projection area of its "head", while substitution of one or two saturated acids to unsaturated ones increases the projection area 25%.

Adaptation, Physiological↗
PubMedDate not supplied

[Thiamine content and enzyme activity in blood cells in leukemia].

Content of thiamine and activities of two enzymes were studied in blood cells of patients with various types of leukosis. In patients with acute leukemia content of thiamin was decreased in leucocytes and blood plasma. Content of vitamin B1 was increased in erythroid cells of peripheric blood in erythroleukosis. Administration of thiamin into some patients caused a distinct increase in its content in blood cells. The guanosine phosphorylase activity was higher in blood cells in leukosis as compared with control. The transketolase activity was not distinctly altered.

Acute Disease↗