Commissioning of heating neutral beams for COMPASS-D tokamak.

Two neutral beam injectors have been developed for plasma heating on COMPASS-D tokamak (Institute of Plasma Physics, Prague). The 4-electrodes multihole ion-optical system with beam focusing was chosen to provide the low divergence 300 kW power in both deuterium and hydrogen atoms. The accelerating voltage is 40 kV at extracted ion current up to 15 A. The power supply system provides the continuous and modulated mode of the beam injection at a maximal pulse length 300 ms. The optimal arrangement of the cryopanels and the beam duct elements provides sufficiently short-length beamline which reduces the beam losses. The evolution of the impurities and molecular fraction content is studied in the process of the high voltage conditioning of the newly made ion sources. Two injectors of the same type have been successfully tested and are ready for operation at tokamak in IPP, Prague.

[Pharmacologic analysis of the role of catecholamines in the mechanism of alcoholic affection of the heart]. / Farmakologicheskii analiz roli katekholaminov v mekhanizme alkogol'nogo porazheniia serdtsa.

The authors studied the effect of 6-oxidopamine and rausedyl on the manifestation of cardiac disorders in rats given 3-5 g/kg ethanol by way of the stomach at 12-hour intervals for 5.5 days. 6-oxidopamine was injected intraperitoneally in a dose of 50 mg/kg 24 hours before the beginning of alcoholization and one hour after the first administration of ethanol. Rausedyl was given in a dose of 0.5 mg/kg by the intragastric route once a day during alcoholization. It was established in perfusion of an isolated rat heart that ethanol induces decrease of cardiac rhythm and rate of relaxation of the heart and coronary duct, increase of systolic and diastolic pressure in the left ventricle, and escape of creatine phosphokinase from the heart. 6-oxidopamine fails to influence while rausedyl weakens the effect of ethanol on heart contractility. Both compounds reduce the escape of creatine phosphokinase from the heart approximately by 40%. It is concluded that the destructive effect of ethanol on the cardiomyocytes is mediated partly by catecholamines. The authors suggest that the cardiotoxic effect of catecholamines in alcoholic intoxication is realized not fully because ethanol weakens their negative action on the heart.

[Determination of the leading factors in the pathogenesis of an alcoholic lesion of the heart]. / Opredelenie vedushchikh faktorov v patogeneze alkogol'nogo porazheniia serdtsa.

Male rats were given per os 25% ethanol solution twice a day at 9.00 and 21.00 for 5.5 consecutive days. Every single dose was 2 to 5 g/kg 2 and 12 hours after 8th gavage ethanol, acetaldehyde and acetone concentrations were measured in blood, 2-8 hours after the last (11th) gavage isolated hearts were perfused by Krebs-Henseleit solution. Applying of Spearman rank correlation method demonstrated negative correlation between mean acetaldehyde concentration and maximal systolic pressure, tension-time index of left ventricle and velocity of contraction and relaxation. Negative correlation has been shown between maximal ethanol concentration (MEC) and rate heart whereas positive correlation has been noticed between MEC and leakage of creatine phosphokinase.

Morphofunctional examination of the heart in rats with the alcohol withdrawal syndrome.

Using histochemical methods, light and electron microscopy, authors examined rat heart 2-6 hours, 1, 3, and 7 days after discontinuation of forced intoxication with alcohol. At the same time, they assessed the contractile function and creatine phosphokinase (CPK) activity in the isolated perfused heart, and the development of animal destruction. Ethanol withdrawal was followed by escalation of vascular disorders in the heart, dystrophic changes in the subcellular structures, considerable polymorphism in enzyme distribution and activity, and formation of foci containing disintegrating myocytes with contractures. The contractile function was impaired and CPK release increased in the isolated heart. The changes were most marked 3 days after ethanol discontinuation to disappear after 7 days. Two to seven days after ethanol cessation, 13.1% of rats perished. Cardiac injury due to alcohol withdrawal syndrome may be one of the factors leading to the development of alcohol cardiomyopathy and a cause of sudden death in patients with documented alcohol abuse.

[Comparative characteristics of voluntary and semivoluntary methods of the alcoholization of rats]. / Sravnitel'naia kharakteristika dobrovol'nykh i poludobrovol'nykh metodov alkogolizatsii krys.

Water and ethanol consumption, blood and urine ethanol concentrations were measured in male rats aged 1.5 to 8 months. The animals had ethanol solutions (5-25%) and water as alternate fluid (two-bottle choice) or a 10% ethanol solution as a sole water source. In both cases, the rats did not exceed 7 g/kg of ethanol consumption per day. From 10 a.m. to 16 p.m. the blood ethanol concentration was no more than 0.1 g/l. Ethanol excretion with urine did not go beyond 0.1% of the daily dose. Ethanol consumption was increased by 1-2 g/kg a day if saccharin (0.125%) and sodium chloride (1%) were added to ethanol solution. In this case the withdrawal signs developed after ethanol consumption cessation.