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Biomedical subjects

W O Richter

Publications and source records attributed to W O Richter.

At least 19 recordsLinked to original sources
PubMed1992

[Effect of diuretics on serum lipoproteins].

UNLABELLED: BASICS: Drug treatment of the risk factor hypertension has not led to the expected reduction in morbidity and mortality of coronary arterial disease. A negative effect of antihypertensive drugs on the lipid metabolism is under discussion as a possible cause. MAIN TOPICS: Both the commonly employed thiazide diuretics and chlorthalidone and the loop diuretics furosemide, piretanide and xipamide lead, to varying extents, to an increase in total and LDL cholesterol as well as triglycerides in subjects with normal metabolism. In addition, some diuretics lower the levels of protective HDL cholesterol. These side effects can be avoided--at least in part--by a combination with such drugs as prazosin, pindolol or captopril, which have a favorable effect on metabolism. CONCLUSION: It is recommended to carefully monitor serum Lipoproteins during diuretic treatment so that possible adverse changes may be counteracted by appropriate measures.

Arteriosclerosis↗
PubMed1992

Changes of membrane phospholipid composition of human erythrocytes in hyperlipidemias. I. Increased phosphatidylcholine and reduced sphingomyelin in patients with elevated levels of triacylglycerol-rich lipoproteins.

The composition of red blood cell membrane and plasma phospholipids has been analyzed in patients with hyperlipidemias. In red cells of patients with elevated levels of triacylglycerol-rich lipoproteins, phosphatidylcholine (PC) was raised and sphingomyelin (SM) reduced, resulting in a 20% increase of the membrane PC/SM ratio. In plasma phospholipids of these patients PC and SM levels were also higher and lower, respectively and the plasma PC/SM ratio was elevated by more than 50%. Close positive correlations between plasma and membrane phospholipids were obtained for PC, SM and the PC/SM ratio in normolipidemic and hyperlipidemic donors. Plasmalogen phosphatidylethanolamine (PE), a supposed endogenous protector against lipid oxidation, was reduced by about 20% in red cell membrane lipids in hyperlipidemic patients. Also plasmalogen-PE in plasma tended to be reduced in hyperlipidemic donors. Plasma HDL levels were positively related to the content of plasmalogen PE in the red cell membrane. In conclusion, there are closely related increases in PC/SM ratios in plasma and the red cell membrane in patients with elevated levels of triacylglycerol-rich lipoproteins. It is speculated that decreases in red cell membrane plasmalogen-PE in hyperlipidemic patients could be related to impaired antioxidant protection, possibly as a consequence of reductions in plasma HDL levels.

Adult↗
PubMed1992

Changes of membrane phospholipid composition of human erythrocytes in hyperlipidemias. II. Increases in distinct molecular species of phosphatidylethanolamine and phosphatidylcholine containing arachidonic acid.

The molecular species composition of red blood cell diacyl-phosphatidylcholine (PC), diacyl-phosphatidylethanolamine (PE) and alkenylacyl-PE (plasmalogen PE) has been analyzed in normolipidemic and hyperlipidemic donors. In all three phospholipid subclasses the percentages of the species 16:0/20:4 were increased in hyperlipidemic patients. In diacyl-PE, 18:1/20:4 was also elevated. No changes were observed in the other quantitatively important molecular species containing arachidonic acid at sn-2, namely 18:0/20:4. The rise in 16:0/20:4 in diacyl-PC and diacyl-PE of hyperlipidemic donors was accompanied by a fall in molecular species with linoleic acid (18:2) at sn-2 (in particular 18:1/18:2). In alkenylacyl-PE the elevation of 16:0/20:4 was compensated by a decrease in species with docosatetraenoic acid (22:4) at sn-2 in particular by a fall in 16:0/22:4. Among all donors, the percentages of 16:0/20:4 in diacyl-PC and PE were positively associated with plasma total cholesterol levels. The changes in molecular species composition of PC and PE in hyperlipidemia are expected to alter the function of erythrocyte membrane transport proteins and--if present also in other cell types--to affect eicosanoid metabolism.

Arachidonic Acids↗
PubMed1992

[Characteristics of obese patients in intensive care].

BASIC REMARKS: The frequency of overweight, together with the associated increase in morbidity--in particular coronary heart disease--means that such patients often require intensive care. MAIN POINTS DISCUSSED: The particular features of intensive care of obese patients are the increased risk of aspiration pneumonia (in the presence of lowered pH and elevated gastric juice volume), respiratory insufficiency caused by a reduction in expiratory reserve volume, and a greater incidence of thrombosis and embolism. Ventricular hypertrophy and dilatation results in a reduced cardiac reserve. A clinically unrecognized insulin resistance may become manifest during intensive care. Digoxin, theophylline and aminoglycosides, commonly with a low therapeutic spectrum, when administered on the basis of weight, may lead to dangerously high serum concentrations in the overweight. CONCLUSIONS: At a weight of more than about 100 kg, it must generally be expected that the compensatory mechanisms of the body are exhausted and that there will be an increased susceptibility to additional disorders of homeostasis.

Critical Care↗
PubMed1992

[Effects of beta blockers on lipoprotein metabolism].

PROBLEM: With respect to prevention of its most common complication--mortality from coronary heart disease--treatment of hypertension had disappointed. It is possible that this is due to negative effects of antihypertensives on lipid metabolism. MAJOR TOPICS: The effects of beta blockers on lipid metabolism can be differentiated principally, in accordance with the classification of beta blockers into those with and those without intrinsic sympathomimetic activity (ISA), as also selectivity and non-selectivity. Thus, non-selective beta blockers with no ISA usually lead to an increase in triglycerides of 25% to 30%, and a decrease in HDL cholesterol of about 15%. On average, beta-1 selective blockers result in a smaller increase in triglycerides. Beta blockers with ISA, in contrast, are largely neutral vis-à-vis lipid metabolism. In the individual case, in particular in the presence of hyperlipoproteinemia, the effects cannot be reliably predicted. CONCLUSIONS: Lipoprotein concentrations should be monitored during treatment with beta blockers. If necessary, a change in the agent employed is recommended. In the case of prevention of a second myocardial infarction, for which various studies have unequivocally shown a reduction in mortality associated with treatment with beta blockers with no ISA, these side effects will, however, be accepted--with the exception of extreme changes--for a limited period of time.

Adrenergic beta-Antagonists↗
PubMed1992

[Trans-fatty acids and lipids].

AIMS: Description of the effects of major cis and trans fatty acids on serum lipoproteins. MAIN POINTS DISCUSSED: Trans fatty acids are formed in particular during industrial hydrogenation of oils and fats. Elaidic acid, the most important of the trans fatty acids, has an unfavorable effect on lipid metabolism that results in a negative shift of the HDL/LDL quotient. Nevertheless, due to the low concentrations in a balanced diet, its effects are only slight, and fall within the biological range of fluctuation. CONCLUSIONS: The biological effect of fatty acids varies from one class to another (saturated, mono-unsaturated, poly-unsaturated). A more accurate differentiation would be desirable. On the other hand, the overall effect of the trans isomers of fatty acids on the organism as a whole is small, so that it does not need to be discussed, for example, in dietary counseling.

Dietary Fats, Unsaturated↗
PubMed1992

Dietary N-3 polyunsaturated fatty acids decrease biliary cholesterol saturation in gallstone disease.

Because fatty acid composition of biliary phospholipids influences cholesterol secretion into bile, we investigated whether replacement of n-1 monounsaturated or n-6 polyunsaturated fatty acids with n-3 polyunsaturated fatty acids in biliary phosphatidylcholines reduces supersaturation with cholesterol and prevents precipitation of cholesterol crystals in bile of gallstone patients. Seven patients with radiolucent gallstones in functioning gallbladders were studied before (control) and after 5 wk of dietary supplementation with marine fish oil (11.3 gm/day = 3.75 gm n-3 polyunsaturated fatty acids/day). Duodenal bile was collected for analysis during intravenous infusion of cholecystokinin. Gallbladder emptying in response to cholecystokinin was comparable before and during intake of n-3 polyunsaturated fatty acids. Intake of n-3 polyunsaturated fatty acids increased (p less than 0.001) the fractions of eicosapentaenoic and docosahexaenoic acids and decreased the fractions of linoleic (p less than 0.001) and arachidonic acids (p less than 0.02) in biliary phospholipids. Concomitantly, the molar ratio of cholesterol to phospholipids decreased (-19%; p less than 0.05). As a consequence, the cholesterol saturation index was reduced by -25% (p = 0.01), from 1.60 +/- 0.44 to 1.24 +/- 0.38. However, in vitro nucleation time of duodenal bile was not prolonged. The decrease in cholesterol saturation was not sufficient to prevent nucleation of cholesterol crystals in bile of gallstone patients. In conclusion, our data suggest that cholesterol saturation can be influenced by the fatty acid composition of the phosphatidylcholines secreted in bile.

Adult↗
PubMed1992

Short- and long-term effects of lovastatin and pravastatin alone and in combination with cholestyramine on serum lipids, lipoproteins and apolipoproteins in primary hypercholesterolaemia.

The effects of the HMG CoA reductase inhibitors lovastatin and pravastatin on serum lipids, lipoproteins and apolipoproteins have been studied in 35 patients with primary hypercholesterolaemia. LDL cholesterol was lowered to the same extent by both agents compared on a mg basis of each drug per day. HDL cholesterol was increased by lovastatin but not by pravastatin. The reduction in serum triglycerides, VLDL triglycerides and VLDL cholesterol was more pronounced after lovastatin than pravastatin. After 1 year the effect of combined treatment with 40 mg pravastatin and 8 g cholestyramine on the reduction in LDL cholesterol (-39%) in 13 patients was comparable to that of 80 mg lovastatin plus 8 g cholestyramine (-40%) in 12 patients with identical baseline values. Differences were also found in the effects of the combination therapy with the two drugs on HDL cholesterol, serum triglycerides, VLDL triglycerides, VLDL cholesterol, and apolipoproteins.

Adolescent↗
PubMed1992

Benefit from hypocaloric diet in obese men depends on the extent of weight-loss regarding cholesterol, and on a simultaneous change in body fat distribution regarding insulin sensitivity and glucose tolerance.

Obesity and an android body fat distribution are related to metabolic disorders. We investigated the interdependences between metabolism, overweight, and body fat distribution in 40 moderately obese men before and after weight-loss. Correlations between metabolic parameters and body mass index (BMI) or waist to hip ratio (WHR) were much weaker in this exclusively obese population than in subjects of all weight categories, but the association between BMI and glucose tolerance (r = -.46, P less than .01) increased significantly after weight-loss. The improvement of metabolic parameters was much stronger in men who achieved normal weight (BMI less than 27 kg/m2) than in those who remained obese (BMI greater than 30 kg/m2, P less than .05). The WHR decreased during the diet (P less than .001), and this decrease and the extent of weight-loss were significantly correlated to an increase in insulin sensitivity (r = -.41, P less than .01) and a decrease in glucose area after an oral glucose load (r = .34, P less than .05). The decrease in apolipoprotein B, total cholesterol, and low-density lipoprotein (LDL) cholesterol was significantly correlated only to the extent of weight-loss (r = .34, .31, and .39, respectively; P less than .05). We conclude that it is best to reach normal weight for the normalization of metabolic aberrations. The reduction of cholesterol appears to be dependent on the extent of weight-loss, while the improvement in insulin sensitivity and glucose tolerance apparently is related to both the extent of weight-loss and to a change toward a less android body fat distribution.

Abdomen↗
PubMed1992

Treatment of primary chylomicronemia due to familial hypertriglyceridemia by omega-3 fatty acids.

Primary familial forms of chylomicronemia can lead to acute life-threatening complications, especially acute pancreatitis. The main aim of therapy is to avoid this so-called chylomicronemia syndrome. In 12 patients with primary chylomicronemia due to familial hypertriglyceridemia, the addition of 2.16 g omega-3 fatty acids over 4 weeks and 4.32 g for 8 weeks resulted in a decrease of serum triglyceride levels from 1,624 +/- 333 to 894 +/- 241 mg/dL after 12 weeks. Cholesterol and triglyceride levels in the chylomicron fraction were reduced concomitantly, the apolipoprotein B-100/B-48 ratio increased, very--low-density lipoprotein (VLDL) triglycerides, VLDL cholesterol, and total cholesterol levels decreased, and low-density lipoprotein (LDL) cholesterol showed a tendency to increase, but this finding did not reach significance. High-density lipoprotein (HDL) cholesterol levels remained unchanged, as did the levels of apolipoproteins A-I, A-II, and E, and lipoprotein(a). Apolipoprotein B levels decreased significantly. The decrease of triglyceride levels to still-elevated concentrations was accompanied by a substantial decrease in plasma and whole-blood viscosity and erythrocyte aggregation, which reached normal values. As in chylomicronemia, complications usually occur at triglyceride levels higher than 1,500 mg/dL; patients can still profit from treatment with omega-3 fatty acids, even though triglyceride levels are still substantially elevated. No clinically relevant side effects occurred, with the exception of the manifestation of diabetes mellitus in one patient, which could be reversed after discontinuation of treatment.

Adult↗
PubMed1992

Granulocytes and three-phase bone scintigraphy for differentiation of diabetic gangrene with and without osteomyelitis.

OBJECTIVE: In diabetic gangrene, concomitant osteopathy and soft-tissue infection often render laboratory and roentgenographic signs unreliable as indicators of osteomyelitis. In this situation, scintigraphic methods can be helpful. RESEARCH DESIGN AND METHODS: Relying on the long-term clinical course as the final indicator of presence or absence of osteomyelitis, we prospectively compared in 31 patients three-phase bone scintigraphy with either indium-labeled autologous granulocytes (n = 20) or 123I-labeled antibodies against granulocytes (n = 11). RESULTS: Three-phase bone scintigraphy and imaging with indium-labeled autologous granulocytes yielded sensitivities and specificities of 95 and 70% for bone scintigraphy and 77 and 100% for granulocyte scintigraphy, respectively. One patient with severe angiopathy and proved osteomyelitis had a negative bone scintigraphy but a positive scintigraphy with labeled antibodies against granulocytes. One patient with aseptic bone necrosis presented with a formally false positive result with both methods. CONCLUSIONS: In contrast to former retrospective studies, three-phase bone scintigraphy compares very well with granulocyte scintigraphy. The care of most patients can be managed with clinical data and this widely available scintigraphic method.

Bone and Bones↗
PubMed1992

[Population screening on a population level in Leipzig within the scope of the Bavarian cholesterol project].

Cholesterol determinations of 15.391 inhabitants of Leipzig were carried out in November 1990 within the Bavarian Cholesterol-Screening-Project. The aim of this screening on population basis was to identify individuals with elevated blood cholesterol levels as one of the risk factors of atherosclerosis. Capillary blood cholesterol was measured by means of the Reflotron dry-chemistry system (Boehringer, Mannheim). 27% of the inhabitants of Leipzig show cholesterol levels lower than 5.2 mmol/l as recommended by the European Society of Atherosclerosis Research. Furthermore the characteristic age dependence is seen. In comparison with the town Nürnberg lower mean cholesterol values were found in Leipzig.

Adult↗
PubMed1992

[Metabolic consequences of long-term antihypertensive treatment with co-dergocrine mesylate/nifedipine in high age groups].

Possible metabolic changes during chronic treatment is of specific importance for the development of antihypertensive drugs. The impact of a combination treatment with co-dergocrine mesilate/nifedipine (Pontuc; CAS 8067-24-1 resp. CAS 21829-25-4) on the lipid metabolism as well as hematological and biochemical values was evaluated in a group of hypertensive patients. HDL-cholesterol remained unchanged, whereas total cholesterol and LDL-cholesterol slightly decreased, apoprotein AI increased and apoprotein B decreased. In conclusion the results of this study indicate that co-dergocrine mesilate/nifedipine has no negative impact on the lipid metabolism in patients with essential hypertension.

Aged↗