Palmitate and glucose oxidation by diaphragm of rats with fructose-induced hypertriglyceridemia

Palmitate and glucose oxidation were investigated in isolated hemidiaphragm of rats in which hypertriglyceridemia was induced by dietary fructose. Palmitate oxidation was increased, and glucose oxidation was reduced, in fructose-fed rats, as compared with glucose-fed controls. Glucose incorporation into muscle glycogen was similar in both dietary groups.     

Congenital diverticulum of the left ventricle

The clinical and hemodynamic features in a three-year-old boy with a congenital muscular diverticulum of the left ventricle associated with omphalocele, diaphragmatic hernia, and pyloric stenosis are presented. Preoperative angiocardiograms showed no obstruction to outflow from the diverticulum, the mechanism previously postulated as contributing to the spontaneous rupture and death reported in over half of the patients with this lesion. An intraventricular conduction delay noted on preoperative electrocardiograms disappeared after successful surgical removal of the diverticulum.     

Anomalous drainage of the right superior vena cava into the left atrium as an isolated anomaly. Rare case report

A case of cyanotic congenital heart disease with left ventricular hypertrophy is described. Cardiac catheterization showed a right superior vena cava draining into the left atrium without other cardiovascular abnormality. This is the fifth case of this rare congenital anomaly described in the literature and the first one reported in a male. The patient was 7-months-old when diagnosed. Despite the important right-to-left shunt, after a follow-up of 2 years, growth and development are normal.     

Radiological patterns of obstructive cardiomyopathy of the left ventricle in childhood

The authors report 9 cases of obstructive cardiomyopathy of the left ventricle in childhood. Angiograms performed by the Seldinger technique showed the characteristic radiological features of the disease which may be either idiopathic in origin or associated with an aortic stenosis.     

Contrast bidimensional echocardiography in the morphologic and functional postoperative evaluation of the Senning technique for complete transposition of the great vessels

Contrast bidimensional echocardiographic (2DE) studies were performed in eight patients with d-transposition of the great vessels in the postoperative period of the Senning technique. Contrast was injected into a peripheral vein of all patients, and into the arterial atrium in five in the postoperative period. The 2DE projections used were the four-chamber apical view and four-chamber subcostal view. In all patients it was possible to see and identify the new atrial cavities which greatly resembled the actual anatomy. Early postoperative alternating injections of contrast in both new atria not only achieved the main purpose of delineating the real anatomy, but also permitted more definitive identification of residual shunts.     

Studies on cholesterol metabolism in the diabetic rat

Plasma and hepatic cholesterol levels were determined in rats with severe alloxan diabetes. Significant hypercholesterolemia and elevated hepatic cholesterol content were found, suggesting an expansion of the cholesterol pool in this experimental model. To elucidate the mechanisms leading to cholesterol accumulation, the biliary excretion of cholesterol and bile salts, the pool size and turnover of the trihydroxycholanic acid fraction, and the rate of cholesterol absorption were studied in alloxan diabetic rats. The results of this study indicate that in these animals (1) the biliary excretion of cholesterol and bile salts was significantly increased, and this penomenon was corrected by the administration of insulin; (2) the pool of the trihydroxycholanic acid fraction was expanded, and its rate of daily synthesis was higher than in control animals; and (3) cholesterol absorptive rates were significantly increased. These observations demonstrate that cholesterol conversion into bile salts is enhanced in the alloxan diabetic rat, and suggest that the expansion of its cholesterol pool can be partly due to an increased rate of cholesterol absorption.     

Combined intravenous administration of diazoxide and beta-blocking agent in acute treatment of severe hypertension or hypertensive crisis

Twenty-nine patients with severe hypertension (n = 14) or hypertensive crisis (n = 15) were treated with diazoxide infusion and intravenous injection of a beta blocker. In 13 patients diazoxide was administered first. It gradually reduced mean arterial pressure (MAP) by 16.1 +/- 2.1% (mean +/- SEM), and increased heart rate (HR) by 27.3 +/- 4.1% and plasma renin activity (PRA) by 48.9 +/- 13.0%. Beta blockade thereafter lowered MAP by only 1.2 +/- 1.9% despite reductions of HR by 35.6 +/- 2.2% and of PRA by 17.1 +/- 5.9%. In 16 other patients a beta blocker, when given first, reduced MAP by 3.5 +/- 1.2%, HR by 18.9 +/- 1.8%, and PRA by 24.2% +/- 4.4%. Diazoxide infusion thereafter gradually reduced MAP further by 21.9 +/- 1.9% and raised HR and PRA to pretreatment levels. No complications were observed. Beta blockade before diazoxide infusion effectively prevents a rise in HR above control levels while its acute effect on blood pressure is negligible. It is advisable to use this combined treatment in all situations where the occurrence of tachycardia might be dangerous.     

Effect of clofibrate on postheparin plasma triglyceride lipase activities in patients with hypertriglyceridemia

The lipoprotein lipase (LPL) and hepatic triglyceride lipase (HL) activities of post-heparin plasma were determined by a specific immunochemical method in 17 patients with primary hyperlipoproteinemia before and during treatment with clofibrate. The drug caused a significant reduction of serum cholesterol (11%) and triglyceride (45%) levels. Postheparin plasma LPL activity rose in all subjects, the average change being 46% (P < 0.001). The increase of LPL was positively correlated to the pretreatment LPL activity. There was no correlation between the serum triglyceride concentration and post-heparin LPL activity either before or during clofibrate administration. On the other hand, in the clofibrate responders there was a weak correlation between the relative changes of triglyceride concentration and LPL activity (r = 0.43, p < 0.05). During clofibrate treatment the LPL activity of the hypertriglyceridemic patients was significantly higher than the corresponding value of untreated healthy normoglyceridemic subjects of similar age. The post-heparin plasma HL activity was not influenced by clofibrate.     

A possible role of noradrenaline in the development of myocardial infarction: an experimental study in the isolated rat heart

Isolated rat hearts were perfused with buffer containing noradrenaline 10(-7) to 10(-4) M. A dose-dependent depletion of glycogen and ATP were seen together with a leakage of ASAT and creatine phosphokinase (CK). The damage induced by noradrenaline could be prevented by addition of a beta-blocker (metoprolol), verapamil, or lidocaine to the perfusion medium. When the endogenous myocardial stores of noradrenaline are rapidly depleted by perfusion with tyramine a similar cell damage was demonstrated. Electron micrographs from hearts subjected to noradrenaline showed three different types of cell damage that could be correlated to earlier described findings. The importance of noradrenaline for the ischemic injury was demonstrated. It was hypothesized that acute myocardial infarction may start because of a sudden release of endogenous noradrenaline.     

The significance of right aortic arch in D-transposition of the great arteries

A review of 195 cases of d-TGA disclosed the incidence of right aortic arch to be 8 per cent. In cases associated with VSD and PS the incidence was higher (16 per cent). Fifty per cent of the cases with right arch had other severe cardiac malformation.     

An adverse effect of insulin on the oxygen-release capacity of red blood cells in nonacidotic diabetics.

Oxyhemoglobin dissociation curves (ODC) were performed on blood from newly diagnosed, nonketotic diabetics prior to and following initial insulin treatment and from ambulatory juvenile diabetics before and after their usual morning insulin. In 10 newly discovered diabetics the average P50 at in vivo pH was normal prior to insulin (26.2 mm Hg), decreased to 24.5 mm Hg (p less than 0.005) on the day following the initial insulin administration, and was within normal limits (26.9 mm Hg) when the diabetes was finally well controlled and red cell 2,3-diphosphoglycerate (2,3-DPG) had risen to elevated levels. Oxygen affinity of hemoglobin was closely correlated with the content of red cell 2,3-DPG (r = 0.61, p less than 0.001) but was unrelated to the level of hemoglobin Alc. In 40 juvenile patients the average P50 was also normal prior to insulin administration but was significantly lower 3-4 hr after they had received their usual insulin dose (p less than 0.001). The study indicates that insulin administration to diabetics with high blood glucose levels may lead to transient decreases in red cell 2,3-DPG and in oxygen-releasing capacity of the red blood cells.     

Mechanism of action of phenethylbiguanide (phenformin) in man. III. Interrelationship between ethanol and phenethylbiguanide (PBG) in normal and diabetic subjects

A standard 4-hr ethanol infusion (236 mg/min) after a 3-day fast with and without phenformin (25 mg q.i.d.), with blood drawn every hour for 8 hr, was performed on five normal subjects, eight obese nondiabetics, seven obese chemical diabetics, and four nonobese diabetics. Control infusion induced in all subjects a decline in blood sugar levels during and/or after the alcohol challenge, with a parallel decrease in basal plasma insulin. Hypoglycemia and the decrease in insulin secretion were associated with increased plasma free fatty acid concentration. Addition of phenethylbiguanide (PBG) to the preparatory 3-day fast resulted in a greater drop in the blood glucose levels of the normal control subjects, obese and nonobese diabetics; in the obese nondiabetics, however, a significantly lower degree of blood glucose decrease than control was elicited. Furthermore, obese nondiabetics altered their blood glucose-insulin interaction with apparent increased responsivess of the B cells to PBG. The results suggest that effects of phenformin on blood glucose levels are more dependent on the metabolic state of the patient than on a property of the drug itself.     

Impaired beta-adrenergic stimulation in the uninvolved ventricle post-acute myocardial infarction: reversible defect due to excessive circulating catecholamine-induced decline in number and affinity of beta-receptors

Left ventricular infarction (AMI) was produced in experimental animals and the contractile response to isoproterenol was tested in the isolated perfused heart preparation. Adenylate cyclase activity, phosphodiesterase activity, and beta-receptor binding characteristics were determined in a sarcolemmal preparation of the right ventricle of the same hearts. Three days post-AMI the dose-response curve for isoproterenol of right ventricular dP/dtmax was significantly depressed, while the inotropic effect of histamine was not impaired. Stimulation of adenylate cyclase activity by isoproterenol was reduced by 70% in the membrane preparation, whereas histamine and NaF stimulation rates were unaltered; phosphodiesterase activity was unchanged. In contrast, beta-receptor binding studies with [3H]-DHA1 indicated 74% loss and 10 times lowered affinity (KD) of the remaining beta-receptors, while specific [3H]-QNB1 binding was unchanged. All of the above alterations were prevented by pretreatment with reserpine or metoprolol. It is concluded that these abnormalities in the nonischemic surviving myocardium post-AMI are the result of specific reversible damage of sarcolemmal beta-receptors due to excessive levels of circulating catecholamines.     

The use of noninvasive methods in the evaluation of left ventricular performance in coronary artery disease. I. Relation of systolic time intervals to angiographic assessment of coronary artery disease severity.

Determination of left ventricular performance by external STI was evaluated in 113 patients with possible coronary artery disease undergoing selective coronary artery disease undergoing selective coronary arteriography and left ventriculography. Angiographically determined significant coronary artery disease was considered as 70 per cent obstruction of a coronary vessel. PEPI and PEP/LVET increased with increasing severity of coronary artery disease. LVETI decreased with increasing coronary artery involvement. Presence of prior myocardial infarction or clinically apparent congestive heart failure did not significantly alter mean STI values when groups were compared according to severity of coronary artery disease. LVETI was significantly less for patients with three-vessel coronary artery disease than for those with no significant disease; PEPI and PEP/LVET were significantly greater in those with two- or three-vessel disease than in those without significant disease. Angiographically determined LVEF correlated directly with LVETI and inversely with PEPI and PEP/LVET. Abnormal left ventricular wall motion was associated with decreased LVETI and increased PEPI and PEP/LVET. LVEDP was not significantly different in any of the groups. These findings indicate that externally determined systolic time intervals reflect abnormalities in left ventricular performance which in turn appear more pronounced with increasingly extensive coronary artery disease.     

Cardiac size and function in Paget's disease of bone

We performed non-invasive assessment of cardiac size and function by clinical criteria, standard electrocardiography, chest X-ray, systolic time intervals and echocardiography in 27 patients with Paget's disease of bone and in 20 control subjects. The patients were divided into two groups on the basis of the degree of skeletal involvement (< 15% in Group I and > 15% in Group II). No differences in heart size parameters of left ventricular performance were noted between Group I and controls. Cardiomegaly, increased left ventricular diastolic dimension and increased left ventricular mass indicative of ventricular hypertrophy were found in Group II compared to control subjects. In addition, patients with more extensive skeletal involvement had signs of depressed myocardial contractility, increased left ventricular volumes in diastole and systole and enlarged stroke volume, with no differences in echographic cardiac output compared to Group I and controls.The findings show an above normal incidence of cardiac enlargement and disturbed left ventricular performance in patients with Paget's disease and osseous lesions in > 15% of skeleton. The clinical implications of the altered cardiac function in patients with Paget's disease are briefly discussed.