Bile lipids, platelet aggregability and pro-ApoAI processing in 2 cases of Tangier disease.
Explore the source record for details and available documents.
Apolipoprotein A-I↗
Biomedical subjects
P Roma
Publications and source records attributed to P Roma.
Effects of probucol on the in vivo plasma clearance of human low density lipoproteins in rabbits and on the expression of lipoprotein receptors in vitro.
The purpose of this study was to investigate the effects of probucol on the plasma levels of low density lipoproteins in rabbits and whether the resulting decrease of low density lipoproteins was related to the effects of probucol on the expression of lipoprotein receptors. Probucol administration effectively lowered plasma cholesterol in normal rabbits. Both low density and high density lipoprotein cholesterol decreased, as well as apo B in the former fraction. Probucol had no effect on the fractional catabolic rate of low density lipoprotein while the flux of this lipoprotein decreased to about 50%. Moreover both the binding of lipoproteins to liver membranes and the in vitro uptake of low density lipoprotein by human skin fibroblasts were not affected by the drug. These findings are consistent with an effect of probucol on low density lipoprotein synthesis.
Animals↗
Bile lipid composition and haemostatic variables in a case of high density lipoprotein deficiency (Tangier disease).
A 62-year-old man with clinical and biochemical findings consistent with homozygous Tangier disease is presented. Widespread atherosclerosis was present. Bile lipid analysis showed a low molar percentage of cholesterol with a low saturation index. The data suggest that high density lipoprotein cholesterol may act as a preferential precursor of biliary cholesterol. Coagulation and platelet studies indicated that the patient's platelets were hyper-responsive to aggregating agents and produced an increased amount of thromboxane B2. A platelet storage pool deficiency was also found.
Aged↗
Plasma lipids, lipoproteins and apoproteins in a case of apo C-II deficiency.
A new case of apo C-II deficiency is described. The patient had plasma triglyceride levels ranging from 10.2-30.5 mmol/l. Apo C-II deficiency was confirmed by gel electrophoresis, isoelectric focusing and immunochemistry. In this patient plasma lipoproteins were mainly chylomicrons and very low density lipoproteins, LDL and HDL levels being very low. Infusion of normal plasma effectively reduced plasma triglycerides and enhanced low density and high density lipoproteins cholesterol levels. These data suggest that in vivo a precursor-product relationship exists between triglyceride rich lipoproteins and LDL and HDL, and further stress the role of the lipoprotein lipase-apo C-II system in modulating these metabolic interconversions.
Apolipoprotein C-II↗
A new case of familial LCAT deficiency.
Twenty-eight patients with familial lecithin:cholesterol acyltransferase deficiency have been reported to date. We report a new Italian case who presents the clinical and biochemical characteristics of the disease. Typical disc-shaped high density lipoproteins (d = 1.063-1.21 g/ml) were detected by electron microscopy. An abnormal distribution of apolipoproteins in the different lipoprotein fractions was found by sodium dodecyl sulphate polyacrylamide electrophoresis.
Adolescent↗
Subfractionation of human very low density lipoproteins by heparin-Sepharose affinity chromatography.
Very low density lipoproteins obtained from normolipidemic subjects were fractionated into subclasses by means of affinity chromatography on a heparin-Sepharose column in the presence of MnCl2. The four subfractions eluted at 0.05, 0.12, 0.20, and 0.38 M NaCl and they differed in chemical composition and apoprotein pattern. The relative amounts of apoB and apoE in subfractions increased with increasing concentrations of the NaCl eluant. Modification of the arginyl residues with 1-2 cyclohexadione demonstrated that arginine plays an important role in determining the elution pattern of VLDL. In vitro studies indicated that only fractions eluted at 0.2 and 0.5 M NaCl compete with LDL for cellular receptors. These data suggest that the various subfractions may represent VLDL at different stages of catabolism.
Cholesterol↗