The effects of ketamine on the canine coronary circulation

Systemic and coronary haemodynamic measurements have been made in six healthy greyhounds anaesthetized with trichloroethylene. The administration of ketamine in bolus doses of 5 mg/kg, 10 mg/kg and 5 mg/kg followed by an infusion 0.1 mg/kg/min was found to be accompanied by a decrease in arterial pressure and an increase in cardiac output produced by an increase (84%) in stroke volume. Coronary blood flow increased greatly as did myocardial oxygen consumption and there was no change in myocardial oxygen extraction.     

The heats of reaction and temperature rises associated with the setting of bonding resins

DTA has been used to obtain the heats of reaction and temperature rises occurring during the setting of bonding resins. Four products have been examined. There was little difference between these. Setting reactions were highly exothermic and produced substantial temperature rises. Both factors are linearly related to resin volume, thus it is fortunate that this material is employed in small volumes, but problems may arise from spillage or the careless application of excessive quantities.     

THE RENIN–ANGIOTENSIN SYSTEM AND TOTAL BODY SODIUM AND POTASSIUM IN HYPERTENSIVE WOMEN TAKING OESTROGEN–PROGESTAGEN ORAL CONTRACEPTIVES

Measurements of total body sodium and potassium, and of components of the renin-angiotensin-aldosterone system, were made in a group of women who developed hypertension while taking oestrogen-progestagen oral contraceptives. The results were compared with similar measurements made in age-matched women with essential hypertension. Total body sodium and potassium were normal in both groups. Plasma renin-substrate was significantly elevated in the women taking oral contraceptives, while concentrations of active renin were similar and normal in both groups. Thus plasma angiotensin II was significantly elevated in the pill users; overall the product of renin and renin substrate concentrations correlated significantly with angiotensin II. The rise in plasma angiotensin II in conjunction with normal total body sodium could therefore contribute to the increase in blood pressure induced by oestrogen-progestagen oral contraceptives.