Plasma lipid oxidation and susceptibility of low-density lipoproteins to oxidation in male patients with stable coronary artery disease.

Objectives: Oxidative modifications of low-density lipoproteins (LDL) are considered to be important in the pathogenesis of atherosclerosis. However, the data on the association between LDL oxidation and severity of clinical manifestations of coronary artery disease (CAD) are contradictory. Previous reports were concerned mostly with unstable angina patients.

Structure and possible biological roles of Lp(a).

Lipoprotein(a) [Lp(a)] is a plasma macromolecular complex that is assembled from low-density lipoproteins (LDL) and a large hydrophilic glycoprotein, named apolipoprotein(a) [apo(a)], linked by a disulfide bond to apolipoprotein B-100. Apo(a) is formed by different structural domains one of which is present in multiple copies, the number of which is determined by variation in the hypervariable apo(a) gene. Sequence homology of apo(a) with plasminogen may explain the competition of Lp(a) for some physiological functions of plasminogen in the coagulation and fibrinolytic cascade in vitro.

Lysine-binding species of lipoprotein(a) in coronary artery disease.

Elevated levels of plasma lipoprotein(a) [Lp(a)] have frequently been associated with coronary artery disease (CAD). Recently Lp(a) was fractionated into two species with different affinities for Lysine-Sepharose. The influence of lysine-binding heterogeneity of Lp(a) on its cardiovascular pathogenicity has not previously been studied.

Adhesion of mouse hepatocytes to type I collagen: role of supramolecular forms and effect of proteolytic degradation.

Mouse hepatocytes were found to adhere much stronger to intact native type I collagen than to native, telopeptide-devoid collagen. Removal of telopeptides (by pepsin treatment) caused disintegration of supramolecular collagen aggregates. Similar differences in hepatocyte adhesion were observed between oligomeric and monomeric collagens separated from intact native preparations.

Roles of immobilized glycosylated proteins and lipoprotein(a) in adhesivity of endothelial cells: possible implications for atherogenesis.

The adherence of peripheral blood monocytes to adult bovine endothelial cells grown to confluence in the microplates was studied. The microplates were coated with different proteins or used without special treatment. It was shown that endothelial cells seeded on immobilized glycosylated proteins (serum albumin or skin gelatin) adhered more monocytes than the cells grown on non-modified proteins.

A fluorescence study of apolipoprotein localization in relation to lipids in serum low density lipoproteins.

Fluorescence energy transfer studies were carried out on low density lipoproteins (LDL) containing pyrene, in order to investigate their structure. The results indicate that almost all of the LDL tryptophan residues are located in the same surroundings near the surface of the particle and are immersed in the lipid phase 10-20 A below the lipid/water interface. The data do not support a model of protein spikes protruding from the particle surface.

Serum lipoproteins of patients with glycogen storage disease.

Seventeen patients with different types of glycogen storage disease (GSD) were under observation. The type of the disease was defined from glucaemic and lactotaemic curves obtained in glucose, galactose and adrenaline tolerance tests and by biochemical analysis of liver biopsy specimens. Seven patients were found to have Type I; five patients, Type III; one patient, Type VI; and four patients, the Type IX (or X) of GSD.

Two cases of unusual Type I glycogenosis.

Two patients with apparent clinical manifestations of glycogen storage disease were described. The curves obtained upon glucose and adrenalin tolerance tests were indicative of glycogen storage disease Type I. Liver biopsies showed the increased glycogen concentration; however, the activities of the enzymes involved in glycogen metabolism, including glucose-6-phosphatase activity, were within normal limits or even slightly enhanced.