The role of the low density lipoprotein receptor (LDLR) in the clearance of apo-B48-containing lipoproteins and the role of the LDLR-related protein (LRP) in the removal of apo-B100-containing lipoproteins have not been clearly defined. To address these issues, we characterized LDLR-deficient mice homozygous for an "apo-B48-only" allele, an "apo-B100-only" allele, or a wild-type apo-B allele (L...

OBJECTIVES To determine levels of apolipoprotein (apo) A-I and apo H in the vitreous fluid of patients with proliferative diabetic retinopathy (PDR) and to examine whether apo A-I and apo H messenger RNA (mRNA) levels are overexpressed in the diabetic retina. METHODS Vitreous samples from 4 diabetic patients with PDR and 8 nondiabetic patients with macular hole were selected for proteomic ana...

Apolipoprotein (apo) E is synthesized by cells of the central and peripheral nervous systems, and its synthesis and secretion in the peripheral nervous systems, and its synthesis and secretion in the peripheral nervous system of animals are greatly stimulated following Wallerian degeneration. It has been suggested that apo E functions in the metabolism of myelin lipids, but its physiologic role...

OBJECTIVE This study was performed to investigate whether a high ratio of apolipoprotein B to apolipoprotein A1 (apo B/apo A1 ratio) is significantly associated with the risk of developing non-traumatic osteonecrosis of the femoral head (ON). METHODS Fifty consecutive non-traumatic ON cases were compared with 50 age and sex matched controls, using both univariate and stepwise discriminant ana...

Using "high-performance" anion-exchange chromatography, we isolated and quantified human C apolipoproteins (apo C) from very-low-density lipoproteins (VLDL) in serum. As revealed by isoelectric focusing and double immunodiffusion against monospecific antisera, apo C-I, apo C-II, apo C-III0, apo C-III1, and apo C-III2 were purified to homogeneity. Assay reproducibility (coefficients of variation...

In this investigation in cultured human fibroblasts, an attempt was made to determine the optimal metabolism of apolipoprotein (apo) B-100 lipoproteins from normolipidemic human subjects. We supplemented culture systems containing 125I-lipoproteins with exogenous recombinant or plasmatic apo E-3. Very low density lipoprotein (VLDL) fractions I, II, and III, and low density lipoproteins (LDL) we...

Lipoprotein(a) [Lp(a)] has been measured in numerous clinical and epidemiological studies by a variety of immunochemical methods. However, little, if any, consideration has been given to the confounding effect of the size heterogeneity of apolipoprotein(a) [apo(a)] on the measurement of Lp(a). We developed three direct-binding enzyme-linked immunosorbent assays (ELISAs) with detecting antibodie...

Apolipoprotein (apo) A-IV is a protein component of triglyceride (TG)-rich lipoproteins and high density lipoproteins (HDL). Plasma apo A-IV levels were measured by immunoelectrophoresis and these values were related to other biological variables in 723 middle aged and elderly men and women (more than 90% of them were Caucasian) prior to participation in a lifestyle modification program. Apo A-...

apo E has been shown to modulate cholesterol balance in arterial wall cells. Production of apo E by macrophages in atherosclerotic plaques could thereby influence the development of the plaque lesion. Cytokines, including TNF alpha, have been identified in human lesions, therefore, we undertook a series of studies to evaluate the effect of TNF alpha on monocyte/macrophage apo E production. The ...

Levels of Lp(a), an atherogenic lipoprotein that circulates in human plasma, are increased by the administration of growth hormone (GH). Many of the physiological effects of GH are mediated through insulin-like growth factor-1 (IGF-1), but ironically, IGF-1 treatment of humans is associated with a fall in plasma Lp(a) levels. To glean insight into the mechanism responsible for the GH-associated...