Local infusion of urokinase and heparin into renal arteries in impending renal cortical necrosis.

Two patients with presumed impending cortical necrosis, after haemolytic uraemic syndrome in one and after concealed accidental haemorrhage in the other, were treated by local infusion of urokinase and heparin into the renal artery. Both recovered and one regained normal renal function. Local infusion of anticoagulants or thrombolytic drugs into one renal artery offers the possibility of a controlled examination of the efficacy of this treatment in preventing cortical necrosis.     

Preventing thromboembolism after myocardial infarction: effect of low-dose heparin or smoking.

A trial of low-dose subcutaneous heparin to prevent thromboembolic complications after myocardial infarction was carried out in 78 patients. Of the 37 heparin-treated patients only two (5%) developed evidence of leg vein thrombosis, while 14 (34%) of the 41 controls did so, and five controls developed pulmonary emboli. Leg vein thrombosis developed in 12 (50%) of the 24 controls who did not smoke cigarettes but in only two (13%) of the 17 controls who were cigarette smokers. Non-smokers who have a myocardial infarction should be given low-dose heparin subcutaneously to prevent leg vein thrombosis and pulmonary embolism.     

Stability of streptokinase in various infusion media at different temperatures

A solution of the streptokinase preparation Awelysin in the infusion media 0.9% NaCl Elektrolyt-Infusionsl?sung 153 and Haemaccel 35 can be stored at room temperature for 24 hours without considerable decrease in activity. This is true not only for concentrations of 50,000 IU/ml but also for dilutions up to 1,000 IU/ml. Solutions made with glucose or fructose infusion media have to be stored in the cold.     

Effect of prostaglandin A1 infusion in hypertensive patients with renal artery stenosis

Clinical data, arteriographic findings, peripheral and renal vein plasma renin activity (PRA) studies and responses to prostaglandin A1 infusion are presented from observations in seven hypertensive patients with renal artery stenosis. PGA1 infusion caused an increase in PRA and urine sodium excretion but no significant change in blood pressure. Exaggerated increases in PRA were observed in five patients. With cessation of PGA1 infusion PRA returned toward pre-infusion levels. In two patients bilateral renal and peripheral vein PRA's were determined before and during PGA1 infusion. PGA1 caused a greater increase in renal vein PRA than in peripheral vein PRA indicating a direct enhancement of renin secretion. These studies indicate possible relationships between the vasoactive prostaglandins and the renin-angiotensin system in the pathogenesis of hypertension due to renal artery stenosis.     

Hemodynamic and renal effects of low-dose brain natriuretic peptide infusion in humans: a randomized,placebo-controlled crossover study

Brain natriuretic peptide (BNP) is a cardiac hormone with natriuretic activity. The aim of this study was to investigate the cardiovascular effects of pathophysiological levels of BNP on central hemodynamics, cardiac function, renal hemodynamics and function, and microvascular hemodynamics in healthy subjects. In this double-blind, placebo-controlled crossover study, we intravenously infused BNP (4 pmol. kg-1. min-1) or placebo for 1 h on two separate days in 12 healthy subjects (mean age, 60 +/- 5 yr). Nailfold and conjunctival capillary density, finger-skin (thermoregulatory) microvascular blood flow, and cardiac output were studied before and after infusion using intravital videomicroscopy, laser-Doppler fluxmetry, and echocardiography, respectively. Furthermore, during infusion, we measured the effective renal plasma flow and glomerular filtration rate using p-aminohippurate and inulin clearances. Blood pressure and heart rate were monitored for all measurements. Compared with placebo, BNP significantly decreased stroke volume with a tendency to decrease cardiac output. With subjects in the sitting position, mean arterial pressure decreased and heart rate increased after BNP infusion, whereas with subjects in the supine position, these variables remained unchanged. BNP increased natriuresis, diuresis, glomerular filtration rate, filtration fraction, and filtered load of Na+ compared with placebo, whereas effective renal plasma flow did not change. BNP did not affect the microvascular capillary density of conjunctiva and skin, microvascular blood flow, total skin oxygen capacity, and postocclusive recruitment. These results suggest that BNP has predominantly central and renal hemodynamic effects; however, it does not influence peripheral microcirculation in skin and conjunctiva.     

Metabolic effects of low-dose incremental insulin infusion in diabetic man

An incremental insulin infusion technique to assess insulin action at physiological circulating levels in diabetic man is described. Insulin was infused during sequential one hour periods at rates of 0.01, 0.05 and 0.10 u/kg/h. Serum free insulin concentrations had reached a plateau by the second 30 minutes of each infusion period. Blood glucose concentrations fell at a similar rate during the two lower rates of insulin infusion, but the fall was significantly greater with the highest insulin infusion. Glucose production and utilisation were measured isotopically using a 3-3H glucose infusion technique. Glucose production was inhibited with the lowest insulin infusion rate and a marked increase in glucose metabolic clearance rate occurred with the highest insulin infusion. Key intermediary metabolites were measured and blood glycerol, total ketone bodies, and plasma non-esterified fatty acids fell with the lowest insulin infusion rate. It is concluded that this technique allows identification of the effect of insulin upon different metabolic processes.