SITE OF 1-METHYLADENINE RECEPTORS IN THE MATURATION OF STARFISH OOCYTES.

Maturation of vitelline coat-free (VCF) oocytes of the starfish, Asterina pectinifera, was studied. When the oocytes, the vitelline coats of which were elevated by adding the ionophorc A-23187, were forced through two sheets of copper mesh, the vitelline coats were completely removed from the oocytes. Although some of the VCF oocytes underwent germinal vesicle breakdown following this mechanical treatment, most of them retained the normal germinal vesicles.

Studies on lipid and carbohydrate metabolism during surface-induced deep hypothermia with circulatory arrest for open-heart surgery.

Plasma lipids, blood glucose, plasma insulin (IRI) and serum dopamine-beta-hydroxylase (DBH) were measured in 30 subjects undergoing surface-induced deep hypothermia with circulatory arrest for open-heart surgery. Non-esterified fatty acid (NEFA) in the plasma rapidly increased at the lowest temperature (23 degrees C) reached and other lipids in the plasma decreased during the cooling period. An increase of NEFA and a decrease of triglyceride have been attributed to the action of lipoprotein lipase activity stimulated by heparin.

The role of the liver in the changes of acid-base balance and plasma lipids during surface-induced deep hypothermia.

The role of the liver in the changes of acid-base balance and plasma lipids in surface-induced deep hypothermia for open-heart surgery was investigated clinically and experimentally. The metabolic acidosis generally observed in open-heart surgery under surface-induced deep hypothermia is derived from lactacidemia. Although the accelerated anaerobic glycolysis is partly responsible, the depressed acidic metabolite-disposing ability of the liver also plays an important role.

Experimental studies on myocardial metabolism of carbohydrate and lipid in surface-induced deep hypothermia.

In surface-induced deep hypothermia, metabolic acidosis resulting from lactacidemia was observed. In the aspect of myocardial metabolism, the rate of reduction in coronary A-V difference ratio of lactate, pyruvate and NEFA was less than that of coronary flow and myocardial oxygen consumption in the hypothermic heart. Namely, it seems that lactate, pyruvate and NEFA play an important role as energy fuel in the hypothermic heart.

Mutant of Escherichia coli that instantaneously loses the ability to adsorb lambda bacteriophage upon exposure to high temperature.

lad (lambda adsorption), an Escherichia coli mutant that loses the ability to adsorb lambda phage immediately after a shift to high temperature (e.g., 42 C), was isolated.

Experimental studies on myocardial metabolism of carbohydrates and lipids in surface-induced deep hypothermia.

In surface-induced deep hypothermia, metabolic acidosis resulting from lactacidemia was observed. In the hypothermic heart, the rate of reduction in the coronary arteriovenous (A-V) difference ratio of lactate, pyruvate, and nonesterified fatty acids (NEFA) was proportionately less than that of coronary flow and myocardial oxygen consumption, suggesting that lactate, pyruvate, and NEFA play important roles as energy fuels in the hypothermic heart. Myocardial metabolism of glucose was reduced; exogenous corticosteroids and ATP do not influence the myocardial metabolism of carbohydrates and lipids in the hypothermic heart.

Metabolic changes in surface-induced deep hypothermia combined with cardiopulmonary bypass for cardiac surgery.

Surface induced deep hypothermia combined with cardiopulmonary bypass (combined method) is excellent in open heart surgery of infants which combines each advantage of cardiopulmonary bypass and hypothermia. The present study was performed to investigate pathophysiological changes, especially metabolic changes, in combined method induced by two stressors such as cardiopulmonary bypass and hypothermia. In general, metabolic changes during hypothermia are temporarily enhanced immediately after the start of cardiopulmonary bypass.

Pathogenesis and treatment of metabolic acidosis in open heart surgery under surface induced deep hypothermia.

Metabolic acidosis observed in open heart surgery under surface induced deep hypothermia is due to lactacidemia, but is reversible, returning to precooling level 24 hours after the operation, and it can be considered more or less as a pathognomonic finding. Although the correction of acidosis present did not influence the level of lactic acid in blood, it was found to be clinically advantageous during the heartresuscitation. Therefore, it is advisable to maintain acid-base balance within-10 mEq per 1 of base excess.