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Biomedical subjects

F R Heller

Publications and source records attributed to F R Heller.

At least 37 records · Page 2Linked to original sources
PubMed1992

The density, contour, and thickness of the pancreas in diabetics: CT findings in 57 patients.

Insulin has a trophic effect on pancreatic acinar tissue, so the pancreas might be expected to atrophy in persons who have diabetes. Accordingly, we analyzed the density, contour (smooth or lobulated), and thickness of the pancreas on CT scans of diabetic patients and compared the results with those in control subjects. The prevalence of pancreatic lobulation (incisurae deeper than 2 mm) and its correlation with age in diabetic and control subjects were determined. The thickness of the pancreas was measured at three levels (head, body, tail). Three groups of diabetic patients were examined: 20 insulin-dependent patients, 25 patients not treated with nor dependent on insulin, and 12 patients treated with but not dependent on insulin. A control group included 57 nondiabetic patients. The ages of the control subjects were similar to those of the diabetic patients. The statistical significance of the differences between groups of diabetic patients and control subjects was estimated by using Student's t test for the values of density and thickness and the chi 2-test for the prevalence of pancreatic lobulation. The density of the pancreas in diabetic patients and control subjects was not statistically different. Diabetic patients had increased lobulation of the pancreas. All parts of the pancreas tended to be smaller in diabetic patients, but the degree of reduction varied. It was modest in the patients not treated with insulin, pronounced in insulin-dependent patients, and intermediate in non-insulin-dependent, insulin-treated patients. Moreover, the size of the body was significantly reduced in all three groups, whereas the size of the pancreatic head was preserved in patients not treated with insulin. In conclusion, CT of the pancreas shows that although density in diabetic patients is normal, lobulation is increased. Reduction in size involves the body of the pancreas more than other parts of the gland and is more pronounced in insulin-treated diabetic patients. CT of the pancreas might be useful to predict which diabetic patients will require insulin therapy.

Adult↗
PubMed1991

[Unexplained fever or inflammatory syndrome. Diagnostic value of liver puncture-biopsy].

The value of transcutaneous biopsy of the liver was assessed in a series of 110 cases of fever of unknown origin or of unexplained inflammatory syndrome. Liver histology was useful to the ultimate etiological diagnosis in 12 cases (11 per cent). The result of a transcutaneous biopsy of the liver was considered an essential aid to the ultimate diagnosis in 7 of these 12 cases. A hepatic lesion regarded as useless for the ultimate diagnosis was present in 16 cases (14.5 per cent). In the other cases, hepatic histology was normal or showed a non-specific reactive hepatitis. Unicteric cholestasis was present in 73 per cent of the cases but was of no predictive value for the detection of a useful hepatic lesion. On the other hand, serum transaminase levels were significantly higher when a useful lesion of the liver was observed.

Adolescent↗
PubMed1991

The lipoprotein(a). Significance and relation to atherosclerosis.

Lipoprotein(a) has many similarities to low density lipoproteins but possesses a unique protein moiety called apolipoprotein(a). The plasma concentration of lipoprotein(a) is mainly under genetic control and most of diets and hypolipidemic drugs do not change its level. Only nicotinic acid and neomycin are able to reduce its concentration. Epidemiological studies suggest that high level (greater than 30 mg/dl) of lipoprotein(a) is an independent risk factor for atherosclerosis of the coronary and carotid arteries. The risk is highest in patients with hypercholesterolemia. The atherogenic role of lipoprotein(a) is attributed to the lack of its recognition by the cellular receptors and its consequent diversion to the atherogenic "non receptor" pathway. Due to its strong homology with plasminogen, lipoprotein(a) could also favour thrombosis. It is suggested that its determination is of importance when evaluating a patient with atherosclerosis. Reducing high plasma levels of cholesterolemia appears to be mandatory when plasma lipoprotein(a) concentration is higher than 30 mg/dl.

Apolipoproteins↗
PubMed1990

[Hypoxic hepatitis. Prospective, clinical and hemodynamic study of 45 cases].

The authors report 45 episodes of centrilobular liver cell necrosis, called ischemic hepatitis, in 43 cardiac patients. In 75 percent of the episodes, centrilobular liver cell necrosis was preceded by a period of progressive deterioration of myocardiac function. In 100 percent of the episodes, liver cell necrosis occurred after an acute clinical event inducing a transient fall of cardiac output. Shock was observed in only 47 percent of the episodes. The biological hallmarks of this centrilobular liver cell necrosis were a massive increase in serum aminotransferase levels and in 85 percent of the episodes, a decrease in the prothrombine time below 50 percent of control level. The mortality rate, 15 days after admission, was 42 percent. Prognosis was mainly related to cardiac function. The hemodynamic comparison between the 45 episodes of centrilobular liver cell necrosis and 22 cases of cardiogenic shock without liver cell necrosis showed that, besides hepatic ischemia, passive venous congestion of the liver and arterial hypoxemia were also involved in the onset of liver cell necrosis in these cardiac patients. Among these 45 episodes of liver cell necrosis of cardiac origin, a unique case of hepatic necrosis secondary to major hypoxemia and passive venous congestion, despite an high cardiac output was observed and is reported in detail. Accordingly, the appellation "hypoxic hepatitis" seems to be more appropriate than "ischemic hepatitis".

Adult↗
PubMed1989

An improvement of Barter's method for assaying plasma cholesterol ester transfer activity: experimental and clinical applications.

The use of a discontinuous density gradient and of a vertical rotor to separate plasma lipoproteins are modifications of Barter's described method for assaying cholesteryl ester transfer activity (CETA) in plasma. The original feature of our approach is the fast preparation of the labeled substrate by a physiologic-like process, which renders the assay easy and suitable for measurement of this activity in both man and animals.

Adult↗
PubMed1988

Changes in plasma activities of lipolytic enzymes and lipids of normolipidemic subjects given phenobarbital, a strong microsomal inducer, alone or in combination with fenofibrate.

Eight male, normolipidemic, non-obese subjects were given fenofibrate (F) (300 mg daily) for eight days (period F). After a wash-out period of four weeks, phenobarbital (P) (100 mg daily) was given for eight days (period P). At the end of this period, P was continued at the same dosage but F (300 mg daily) was added and both drugs were given simultaneously for a further eight-day period (period P + F). The plasma concentrations of lipids and the plasma activities of enzymes involved in the interconversion of plasma lipoproteins: lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT) were measured before and at the end of each period of treatment. Fenofibrate induced a decrease in the plasma concentration of triglycerides (TG), total cholesterol (TC), apoB and an increase in the plasma activities of LPL and LCAT. Phenobarbital induced a decrease in the plasma concentration of TC, HDL-C and LDL-C (with an unchanged HDL-C/LDL-C ratio) and in the plasma activity of LPL. Addition of P to F did not modify the hypolipidemic action of F but the increase of LPL activity during period P + F was found to be greater than that observed during period F. It is concluded that P does not modify the serum lipoprotein pattern in a way which can be considered as beneficial in terms of atherosclerosis. By measuring the serum concentration of unconjugated bilirubin, the plasma clearance of antipyrine and the urinary excretion of 6 beta-hydroxycortisol as parameters of hepatic microsomal induction, F appeared to be a slight inducer as compared with P. Thus, enzyme induction cannot explain the changes in serum lipoproteins induced by P and does not modify the hypolipidemic action of F.

Adult↗
PubMed1987

Short-term effects of beta blockers atenolol, nadolol, pindolol, and propranolol on lipoprotein metabolism in normolipemic subjects.

The short-term effect of the blockade of the beta-adrenergic receptors on serum lipoproteins and the plasma activities of the enzymes involved in the metabolism of the serum lipoproteins: lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT) was evaluated in ten healthy normolipemic and normotensive subjects. In the first part of the study, the first three-day period of placebo was followed by another three-day period during which propranolol (120 mg/d) was given. In the second, third, and fourth part of the study, the same schedule was used but pindolol (15 mg/d), nadolol (160 mg/d), atenolol (100 mg/d) were given respectively instead of propranolol. The four drugs induced a significant blockade of the beta-adrenergic receptors as evaluated by the measurement of the double two-step test of Master (-45%). Despite similar blockade, the effect on serum lipid concentrations depended on the type of drug: propranolol induced an increase in triglycerides and apoprotein B-concentrations and a decrease in serum high density lipoprotein cholesterol (HDL-C) and apoprotein AI-concentrations. Pindolol provoked only a slight decrease of serum HDL-C concentration. Nadolol and atenolol elicited a lowering of the same magnitude in HDL-C. Except for a possible slight increase in plasma LCAT activity on propranolol, there was no significant change in the plasma activities of LPL, HL, and LCAT during the blockade of the beta-adrenergic receptors with the drugs used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Fast separation of the three main plasma lipoprotein classes by ultracentrifugation using vertical rotor and multiple discontinuous density gradient.

An ultracentrifugation technique for isolation of the various lipoprotein fractions using a vertical rotor is described. By the use of a multiple discontinuous density gradient, very low density lipoproteins, low density lipoproteins and high density lipoproteins are sharply separated, without contamination of other lipoproteins or albumin. Centrifugation time is 80 min. The densities, electrophoretic mobilities, electron microscopic appearance and chemical composition are those of the expected classes of lipoproteins. Two different gradients are used to enhance the separation of very low density lipoproteins from low density lipoproteins on one hand and high density lipoproteins from infranatant on the other.

Centrifugation, Density Gradient↗
PubMed1984

Cholesterol content and cholesterol esterifying activity of various organs in guinea pigs.

In various organs of the guinea pig, the total cholesterol content of an organ was significantly correlated with the percentage of esterified cholesterol present in this organ. Cholesterol esterifying capacity was shown in most organs, with highest activities in the adrenals, the spleen and the liver. The significant correlation found between the cholesteryl ester content of an organ and its acyl cholesterol acyltransferase activity suggests a possible role of this enzyme in determining the level of the total and esterified cholesterol in a tissue.

Adrenal Glands↗
PubMed1983

Adipose tissue and skeletal muscle lipoprotein lipase and hepatic lipase activities in cholesterol-fed guinea pigs.

In control and in cholesterol-fed (1%) guinea pigs, the lipoprotein lipase activities of adipose tissue and skeletal muscle and the hepatic lipase activity were assayed after elution of the enzymes from tissues by heparin. The lipoprotein lipase activities were similar in the two groups of animals; the hepatic lipase activity was found be significantly increased in the animals fed cholesterol.

Adipose Tissue↗
PubMed1983

Cholesterol esterifying capacity of various organs in cholesterol-fed guinea pigs.

In guinea pigs fed a diet enriched with 1% cholesterol, the liver, adrenals, spleen, and small intestine accumulated cholesterol much more than the lungs and kidneys. The cholesterol content of the aorta, stomach and colon was not increased by the diet. Cholesteryl ester was the predominant form of cholesterol deposited in the organs richest in this sterol and the total cholesterol content of a tissue tended to increase with the proportion of cholesteryl ester. Cholesterol esterifying activity (ACAT) was found in most tissues and paralleled the cholesteryl ester content of these tissues, being highest in the adrenals, liver, spleen and the proximal part of the small intestine. ACAT activity was enhanced by the cholesterol diet and its elevation was fairly well correlated with the increase in the cholesterol content of the organs. However, the liver and adrenals tended to accumulate more cholesterol than anticipated from their cholesteryl ester content and their ACAT activity. Cholesterol esterification may play a major role in the ability of organs to accumulate cholesterol.

Adrenal Glands↗
PubMed1981

Plasma lipid concentrations and lecithin:cholesterol acyltransferase activity in normolipidemic subjects given fenofibrate and colestipol.

Plasma lipids and lipoprotein cholesterol concentrations and lecithin:cholesterol acyltransferase activity were measured in 7 normolipidemic subjects before, and 7 days after, the administration of fenofibrate (300 mg daily) and colestipol (15 g daily) taken separately or simultaneously. Fenofibrate provoked a significant decrease in the mean plasma triglycerides (26%) and cholesterol (10%) concentration; only plasma cholesterol concentrations were significantly lowered by colestipol (26%). The cholesterol lowering effects of the two drugs were additive as was observed when colestipol was added to fenofibrate. The mean plasma high density lipoprotein cholesterol (HDL-C) concentration was significantly increased by fenofibrate (10%) and when colestipol was added to fenofibrate (15%), but not by colestipol alone. Both fenofibrate and colestipol caused significant reduction of the mean plasma low density lipoprotein cholesterol (LDL-C) concentration and the mean plasma LDL-C/HDL-C ratio (13% and 18%, respectively, with fenofibrate, 44% and 52% with colestipol, and 53% and 62% with colestipol added to fenofibrate). The mean plasma fractional esterification rate was significantly increased by 25% and 12%, respectively, with fenofibrate and colestipol when taken separately, and still more (91%) when colestipol was added to fenofibrate. The mean plasma molar esterification rate was significantly lowered by colestipol, but remained unchanged with the other drug regimens. This study shows that fenofibrate and colestipol given to normolipidemic subjects can induce in a very short period of time (7 days) marked changes in lipoprotein metabolism. Interpretations of the findings in relation to lipoprotein metabolism are discussed.

Adult↗
PubMed1979

Plasma lecithin-cholesterol acyltransferase: lack of induction by phenobarbital in guinea pigs.

Compared with controls, guinea pigs ip injected by phenobarbital for 4 days displayed higher activities of two hepatic microsomial enzymes: aminopyrine N-deme-thylase and benzo(alpha)pyrene hydroxylase. In contrast plasma lecithin-cholesterol acyltransferase (LCAT) activity was not increased by phenobarbital. It then appears that like in humans, plasma LCAT does not seem inducible by phenobarbital.

Aminopyrine N-Demethylase↗