the major lipoprotein classes are heterogenous. human serum high-density-lipoproteins (hdl) are separated into two major subfractions (hdl2, d=1.063-1.125 g/ml, hdl3, d=1.125-1.210 g/ml) by a simple double precipitation method. there was a strong inverse relation between hdl-cholesterol (hdl-c) and subfractions hdl2-c and hdl3-c with atherosclerosis. this study demonstrated that hdl-c (p<0.001)...

To elucidate further the binding of high-density-lipoprotein subfraction 3 (HDL3) to cells, the involvement of glycosylphosphatidylinositol-anchored proteins (GPI-proteins) was studied. Treatment of cultured cells, such as fibroblasts or SK-MES-1 cells, with a phosphatidylinositol-specific phospholipase C (PI-PLC) significantly decreases specific HDL3 binding. Moreover, PI-PLC treatment of cult...

BACKGROUND High density lipoproteins (HDL) protect against cardiovascular disease (CVD). However, increased serum amyloid-A (SAA) related inflammation may negate this property. This study investigated if SAA was related to CVD-burden. METHODS Subjects referred to the rapid chest pain clinic (n = 240) had atherosclerotic burden assessed by cardiac computerised tomography angiography. Subjects ...

AIMS Recent studies suggested that subclasses of high-density lipoprotein (HDL) may be a better biomarker to predict the risk of atherosclerotic disorders. We aimed to examine the association of HDL2- and HDL3-cholesterol (HDL2-C and HDL3-C) with carotid intima-media thickness (IMT) using a new method to quantify the HDL-C subclasses. METHODS Participants were 657 Japanese subjects (434 women...

The dual-precipitation method for measurement of cholesterol in high-density lipoprotein subfractions HDL2 and HDL3 (Warnick et al., Clin Chem 1982;28:1574) was compared with quantification of cholesterol in HDL2 and HDL3 by zonal ultracentrifugation (Patsch et al., J Lipid Res 1974;15:356-66). For 39 plasma specimens differing widely in their HDL subfraction cholesterol concentration, the coef...

In this study we determined in vivo conversions of human 3H-labeled cholesteryl ester-labeled HDL3 [( 3H]CE-HDL3) in male rats and the effects of partially purified lipid transfer protein on the conversion processes. Zonal centrifugation techniques were used to prepare the [3H]CE-HDL3 and to follow the conversion processes. One hour after the injection, a complete conversion of HDL3 to the HDL2...

Although binding of high-density lipoproteins (HDL) to a variety of cells in culture has been widely reported, the mechanism of this binding has yet to be fully elucidated. The aim of the current studies was to explore the roles of apoproteins (apo) AI and AII in HDL3 binding to membranes derived from bovine aortic endothelial cells. Binding studies showed that HDL3 (which contains both apo AI ...

Previous studies from this laboratory employing the technique of optical rotatory dispersion (ORD) have shown that human serum high-density lipoprotein (HDL) of d 1.063-1.21 gm/ml has a high content in a-helix which is to a large extent retained in its lipid-free form, apo HDL.1 On the basis of the ORD parameters, an unordered structure was assigned to the nonhelical portion of the apoprotein, ...

Freshly isolated human adipocytes showed specific uptake of 125I-labeled human high density lipoprotein (HDL2 and HDL3), a portion of which could be released by subsequent incubation with excess unlabeled ligand. To study the mechanism of HDL binding, sucrose gradient-purified adipocyte plasma membranes were incubated with radioiodinated lipoprotein particles under equilibrium conditions in the...

INTRODUCTION Higher levels of high density lipoprotein (HDL) subfractions HDL3-chol and particularly HDL2-chol protect against cardiovascular disease (CVD), but inflammation reduces the HDL level and may impair its anti-atherogenic effect. Changed HDL composition through the impact of inflammation on HDL subfractions may contribute to the excess risk of CVD in rheumatoid arthritis (RA). In this...