[Neuroprotective mechanisms of the ubiquinol action in experimental focal ischemia]. / Issledovanie neiroprotektornykh mekhanizmov deistviia ubikhinola pri éksperimental'noi fokal'noi ishemii.

Ischemic stroke is one of the most socially important diseases characterized by impaired cerebral circulation with focal damage of the brain tissue and decreased functionality. Despite the successes of modern pharmacology, possibilities of pharmacotherapy for stroke remain limited, and the research for new drugs with neuroprotective effects that can prevent brain cell death is still relevant. In this study we have investigated the neuroprotective activity of ubiquinol as a part of an innovative form on a rat model of irreversible 24 h-cerebral ischemia with evaluation of the mechanisms of its neuroprotective effect. Ubiquinol (30 mg/kg), administered intravenously in the acute period of irreversible 24 h focal cerebral ischemia, had a direct neuroprotective effect, characterized by a decrease in the volume of brain tissue necrosis. The protective effect of ubiquinol is due to its ability to inhibit the development of oxidative stress by the direct anti-radical action, preventing the increase in the lipid hydroperoxide content in the brain tissue adjacent to the focus of necrosis, lowering the lipid oxidation rate in plasma against under conditions of increased total antioxidant activity in the brain and blood of experimental animals. In vitro experiments have shown the ability of ubiquinol to prevent cell death in primary culture of cerebral neurons of rat brain under 4 h oxygen/glucose deprivation followed by 20 h reoxygenation.

Effect of Coenzyme Q10 on Expression of UbiAd1 Gene in Rat Model of Local Cerebral Ischemia.

The study examined the effect of endogenous lipid-soluble antioxidant coenzyme Q10 on the expression of UbiA gene of prenyltransferase domain-containing protein 1 (UbiAd1) involved in synthesis of vitamin K2 (and probably of coenzyme Q10) on a rat model of ischemic stroke provoked by ligation of the middle cerebral artery in the left hemisphere. Ischemia enhanced expression of mRNA of UbiAd1 gene in both cerebral hemispheres, but the effect was significant only in the contralateral one. The study revealed no effect of intraperitoneal injection of coenzyme Q10 (30 mg/kg) on ischemia-produced elevation of mRNA of UbiAd1 gene. Further studies are needed to assess possible neuroprotective effects of antioxidant coenzyme Q10.

[Dynamics of ECG voltage in changing gravity].

Comparative analysis of the QRS voltage response to gravity variations was made using the data about 26 normal human subjects collected in parabolic flights (CNERS-AIRBUS A300 Zero-G, n=23; IL-76MD, n=3) and during the tilt test (head-up tilt at 70 degrees for a min and head-down tilt at-15 degrees for 5 min, n=14). Both the parabolic flights and provocative tilt tests affected R-amplitude in the Z lead. During the hypergravity episodes it was observed in 95% of cases with the mean gain of 16% and maximal--56%. On transition to the horizontal position, the Rz-amplitude showed a rise in each subject (16% on the average). In microgravity, the Rz-amplitude reduced in 95% of the observations. The voltage decline averaged 18% and reached 49% at the maximum. The head-down tilt was conducive to Rz reduction in 78% of observations averaging 2%. Analysis of the ECG records under changing gravity when blood redistribution developed within few seconds not enough for serious metabolic shifts still revealed QRS deviations associated exclusively with the physical factors, i.e., alteration in tissue conduction and distance to electrodes. Our findings can stand in good stead in evaluation of the dynamics of predictive ECG parameters during long-term experiments leading to changes as in tissue conduction, so metabolism.

ECG voltage modifications as response to gravity changes.

The aim of the study was to analyze ECG (QRS) voltage responses to body fluid shift due to gravity chances. Acute changes in gravity were created by two ways: 1) changes in gravity value during parabolic flights (within 27 subjects 45 ECG have been analyzed); 2) changes in gravity direction due to rotation of the body during postural tests (within 11 subjects 14 ECG have been analyzed). Results and conclusions. Gravity change leads to body fluid shift and changes of intrathoracic organs and tissues electroconduction. It influences on ECG voltage. During parabolic flights in up-right position: R amplitude in Z axis increases in hypergravity (+0.19 mV) and decreases in microgravity (-0.24 mV). During postural tests, R amplitude in Z axis increases in orthostatic position (+0.09 mV) and decreases in antiorthostatic position (-0.025 mV). Changes in QRS voltage during parabolic flights are more important than during postural tests. This could be due to more effective blood redistribution during parabolic flights.

[Soil pollution by heavy metals in certain agricultural areas of Bashkortostan]. / Zagriaznennost' tiazhelymi metallami pochv nekotorykh sel'skokhoziaistvennykh raionov Bashkortostana.

Three soil-climatic regions of Transural Bashkortostan exemplify a problem of soils pollution with heavy metals. The metals content of soil in the regions is near or slightly exceeding the background level. The studies revealed some features of the metals spread in soil of the regions studied. The metals content of soil in the regions do not restrict agricultural utilization of those soils.

[Lipid peroxidation in open-heart operations]. / Perekisnoe okislenie lipidov pri operatsiiakh na otkrytom serdtse.

The intensity of lipid peroxidation (LPO) and antioxidant system activity (ASA) have been studied using chemiluminescent technique in 15 patients with ischemic heart disease subjected to surgery under moderate hypothermia. Two types of responses to surgical intervention and cardiopulmonary bypass have been demonstrated depending on baseline LPO intensity. Low baseline intensity of free-radical reactions at the beginning of perfusion is first enhanced and then attenuated by the end of perfusion, which is accompanied by ASA activation. This indicates adequate protective and adaptation body reactions. The same group of patients was characterized by a significant correlation between the parameters studied in venous blood and blood outflowing from the myocardium prior to and following the aorta clamping. With high LPO intensity that remained unchanged in the course of the intervention no correlation between LPO and ASA parameters has been observed in venous and coronary sinus blood. These patients develop various cardiovascular complications in the postperfusion period. It has been concluded that high baseline LPO level is prognostically unfavourable, with no correlations between the parameters under study observed in venous blood and blood outflowing from the myocardium.

[Influence of thyroxine on lipid peroxidation in mitochondrial membranes]. / Deistvie tiroksina na perekisnoe okislenie lipidov v membranakh mitokhondrii

In concentrations above 5.10(-7) M thyroxin brought about a delay in chemifluorescence development and decreased the slope of semilogarythmic plot of chemifluorescence curve at the initial step of the fluorescence slow flash. The antioxidant activity of thyroxin was found to be insignificantly lower than that of the well-known antioxidant alpha-tocopherol. In lower concentrations (about 1.10(-8) M) the hormone can act as prooxidant, the effect being the highest in the case of intact mitochondria incubated in the phosphate-containing medium in the presence of Mg2+ ions, and much less in the mitochondria treated in hypotonic medium containing Ca2+ ions.