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Biomedical subjects

P Kostiuk

Publications and source records attributed to P Kostiuk.

4 recordsLinked to original sources
PubMed1991

High-performance liquid chromatographic determination of cholesteryl esters in the blood of obese children.

The serum of obese children and adolescents was analyzed for cholesteryl esters. The test substances were first separated from the sample matrix by solvent extraction and thin-layer chromatography and then resolved in a reversed-phase high-performance liquid chromatographic system involving a Separon SGX C18 column and a mobile phase of 2-propanol-acetonitrile (40:60, v/v), with ultraviolet detection at 206 nm. Cholesterol and 10-cholesteryl esters could be separated and determined within ca. 25 min at a flow-rate of 1 ml/min. The method was applied to a study of the effect of external conditions (physical stress, diet) on the content of cholesteryl esters in a test group of obese boys and girls aged from 13 to 16 years. The analyses have demonstrated that the above conditions do not affect the concentrations of the individual cholesteryl esters, although the total cholesterol concentration decreased significantly after spa treatment.

Adolescent↗
PubMed1989

High-performance liquid chromatographic determination of some polar phospholipids in serum.

The experimental conditions have been optimized for high-performance liquid chromatographic determination of phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM) in serum. The phospholipids are separated on a silica gel column, using a mobile phase of acetonitrile-methanol-water (100:10:18, v/v), with ultraviolet photometric detection at 200 nm. The limit of detection was 0.2 micrograms (in 20 microliters) for natural phospholipids and 2.5 micrograms for synthetic phospholipids; the relative standard deviation was ca. 5%. An alternative detection is tensammetry at a mercury electrode, at a potential of -1.8 V, with an a.c. current frequency of 60 Hz and an amplitude of 20 mV. The tensammetric detection has an advantage in its independence of the structure of the phospholipids. In measurements without a column (flow-injection analysis), the tensammetric detection also yields a somewhat lower limit of detection than photometry (0.15 micrograms per 20 microliters), but this value increases more than ten times in chromatographic detection. The precision is poorer and is more susceptible to interferences. The method was applied to the determination of the above substances in the blood of obese children, as a function of physical stress and spa treatment. It was shown that physical exercise causes a decrease in the contents of PE and PC in the patients. On the other hand, the spa treatment has no pronounced effect on the phospholipid content in the blood.

Adolescent↗
PubMed1980

2,3-diphosphoglycerate during exercise.

The effect of physical exercise on erythrocyte 2,3-diphosphoglycerate (2,3-DPG) content was studied in eight trained speed canoeists aged 15-25 years. One-stage-4-min load on a paddling ergometer corresponding to a 1 km race was observed. During the test, the following cardiorespiratory parameters were recorded: V, VO2, VO2/kg, HR, VO2/HR, R. Blood lactate level and haematocrit were also determined. The average resting values of 2,3-DPG and haematocrit were statistically significant increased. After 6 months intense training there was a significant increase in 2,3-DPG, and the other parameters were also increased.

Adolescent↗