Characterization of desialylated low-density lipoproteins which cause intracellular lipid accumulation.

The properties of sialylated (sialic acid rich) and desialylated (sialic acid poor) fractions of low-density lipoproteins (LDL) isolated from blood plasma of healthy subjects and coronary atherosclerosis patients have been investigated. Sialylated (60-90% of total LDL) and desialylated (10-40%) LDL were separated by affinity chromatography on Ricinus communis agglutinin-agarose. Sialic acid contents in sialylated LDL fractions of healthy subjects and patients were found to be the same, and 1.

Immunofluorescent study of heterogeneity in smooth muscle cells of human fetal vessels using antibodies to myosin, desmin, and vimentin.

Immunofluorescence-microscopy was applied to study the distribution of desmin, vimentin, and smooth muscle myosin in smooth muscle of human fetal vessels. Serial cryostat sections of the vessels examined all reacted positively with myosin and vimentin antibodies. However, heterogeneous staining of the vessels with desmin antibodies was observed.

Use of cultured atherosclerotic cells for investigation of antiatherosclerotic effects of anipamil and other calcium antagonists.

Calcium antagonists have been shown to exhibit an antiatherosclerotic action in primary cultures of human aortic atherosclerotic cells by causing a reduction in intracellular lipid content, proliferative activity and synthesis of the extracellular matrix. Verapamil and nifedipine exhibited the highest efficacy in this respect. The new calcium antagonist, anipamil (racemate and enantiomers), has been tested in cell cultures.

Improvement in contractile recovery of isolated rat heart after cardioplegic ischaemic arrest with endogenous phosphocreatine: involvement of antiperoxidative effect?

Study Objective: The aim was to attempt to get further insight into the mechanism of the cardioprotective action of phosphocreatine (PCr).

Design: Three experimental protocols were used: (1) The effect was examined of exogenous PCr (10 mmol.litre-1) on myocardial oxidative damage produced by H2O2 perfusion (90 mumol.

Lipoprotein immune complexes as markers of atherosclerosis.

Recently we have demonstrated that cholesterol level in LDL-containing circulating immune complexes (CIC cholesterol) correlates with the presence of coronary atherosclerosis. In the present study we attempted to clarify whether CIC cholesterol level correlates with the severity of coronary atherosclerosis. The second task was to reveal the diagnostic value of CIC cholesterol in comparison with other lipid and lipoprotein parameters used as markers of dislipidaemia associated with atherosclerosis.

Combination of 31P-NMR magnetization transfer and radioisotope exchange methods for assessment of an enzyme reaction mechanism: rate-determining steps of the creatine kinase reaction.

The theoretical analysis of a reversible enzyme reaction performed in this work shows that the 31P-NMR magnetization (saturation) transfer technique combined with a radioisotope exchange method may potentially provide information on the position of rate-determining step(s). It depends on chemical shifts of NMR signals of nuclei of interest in free and enzyme-bound forms of substrate(s) and product(s) of the reaction. The creatine kinase reaction (MgATP + creatine----MgADP + P-creatine) has been used as a model.

Pharmacologic modifications of reperfusion arrhythmias in the dog in vivo: possible relation to limitation of the extent of infarction.

To study the effects of pharmacologic interventions on reperfusion-induced arrhythmias, open chest anesthetized dogs were subjected to occlusion of a coronary artery for 3 hours followed by reperfusion for 3 hours. Electrocardiograms were recorded with a two-channel monitor with the subsequent recordings submitted to computer-assisted analysis. The extent of myocardial infarction was measured by staining with triphenyl tetrazolium chloride.

The apolipoprotein gene family: organization of upstream elements and regulation of gene expression.

The structural organization of the upstream regulatory regions of the apolipoprotein genes is discussed in relation to tissue-specific gene expression. Comparison of the sequences of the regulatory and coding parts of the genes that make up this multigene family shows that some members of the family with homologous coding regions may differ in the organization of their regulatory regions (apoE compared with apoA-IV, apoC-III, or apoC-II). On the other hand, some apolipoprotein genes with different primary structures of their coding regions and different intron-exon organization show similarities in the structural organization of their regulatory regions (e.

Effect of blood viscocity on arterial flow induced dilator response.

Experiments were designed to determine whether blood viscosity affects flow induced dilator response in conduit arteries. Changes in diameter of the femoral artery of anaesthetised cats evoked by stepwise blood flow increases were recorded at normal blood viscocity, at haemodilution, and at haemoconcentration, under conditions of stabilised transmural pressure. Dilator responses caused by the same increments in flow rate increased at haemoconcentration and decreased at haemodilution, in parallel with the changes in blood viscocity.

New-onset angina pectoris: initial characteristics and results of a 6 to 12-month follow-up.

173 patients, aged 46.8 years on the average, were examined in the first 3 months after onset of angina pectoris. 97% of them presented at least one of risk factors (smoking, arterial hypertension, overweight, dyslipoproteinaemia), in 79% two or more risk factors were present simultaneously.

New methods of diagnosing receptor metabolism disturbances of low density lipoproteins.

The authors present new approaches to assessment of various aspects of receptor metabolism for low density lipoproteins in patients with atherosclerosis: the ability of lipoproteins to interact with cell receptors in culture in the presence of nonfractionated serum; analysis of the genetically determined number of LDL receptors on culture cells, and the in vivo lipoprotein uptake in the liver. The ability of apo B-containing lipoproteins in patients with atherosclerosis to interact effectively with cell receptors was confirmed, the activity of LDL receptors on cells in cultures from patients with hypercholesterolaemia was analysed, and a decrease in 99mTc-labelled LDL uptake in the liver of patients with the heterozygous form of familial hypercholesterolaemia was demonstrated. The above approaches could be useful in the choice of individual treatment of clinically manifest atherosclerosis and evaluation of therapeutic efficacy.

"Silent" myocardial ischaemia in essential hypertension.

During 16-h electrocardiographic monitoring of 29 patients with stage II (WHO) essential hypertension and left ventricular hypertrophy, the episodes of painless "silent" myocardial ischaemia were registered in 12. In these patients a bicycle ergometry test, transoesophageal atrial pacing, isotope ventriculography at rest and during isometric exercise, and coronary angiography in 3 cases, were performed. A comprehensive evaluation of findings revealed the presence of coronary insufficiency not accompanied by pain syndrome.

Endothelium dependent control of arterial diameter by blood viscosity.

The local control of arterial diameter by blood flow rate has been attributed to the ability of the endothelial cells to sense the shear stress exerted on them by flowing blood. Since shear stress is proportional to the product of flow rate and fluid viscosity, an increase in the latter will augment shear stress and lead to arterial dilatation as well. We therefore designed experiments to reveal the control of the arterial lumen by blood viscosity and to compare it with the control by blood flow rate.

Features of myocardial metabolism of some amino acids and ammonia in patients with coronary artery disease.

Fractional myocardial extraction/release of glutamate, glutamine, alanine, ammonia, asparagine, glucose and lactate was studied in 12 subjects with normal coronary anatomy (controls) and 28 patients with coronary artery disease (CAD) during rest and atrial pacing. At rest patients with CAD showed an increased myocardial extraction of glutamate, glucose and lactate and an augmented glutamine and alanine release compared with controls. In all CAD patients myocardial ammonia and asparagine release was found at rest, while all controls showed myocardial extraction of these compounds.

Diagnosis of ischaemic heart disease based on data of precordial mapping.

To increase the efficacy of electrocardiographic diagnosis of ischaemic heart disease (IHD), the authors searched for new ECG parameters using the method of precordial mapping and computer map analysis. The study was made in a group of 95 IHD patients, with diagnosis confirmed with the use of visual methods (coronary angiography and left ventriculography). On 12-lead ECG, the signs of focal cicatrization were found in none of examined patients, and ischaemic changes were present in 23% only.

Blood clearance of radiolabeled antibody: enhancement by lactosamination and treatment with biotin-avidin or anti-mouse IgG antibodies.

Methods of rapid blood clearance of 111In-labeled mouse monoclonal antibody 9B9 against angiotensin-converting enzyme were studied. Indium-111-9B9 is specifically accumulated in rat lung, but its blood clearance is relatively slow and target-to-blood radioactivity ratio/g tissue (localization ratio) increases from 11 to 30 only 48 hr postinjection. Injection of second (anti-mouse immunoglobulin) antibodies results in slight (1.

Effects of an extract of feverfew on endothelial cell integrity and on cAMP in rabbit perfused aorta.

Extracts of feverfew inhibit platelet aggregation and secretion of granular contents from platelets and other cells. They also modify the interaction of platelets with collagen substrates: feverfew extracts inhibit both platelet spreading and formation of thrombus-like platelet aggregates on the collagen surface. We have now investigated the effect of an extract of feverfew on the vessel wall using rabbit aortas that were perfused with a physiological salt solution in-situ.

Medical efficacy of a cooperative prevention programme of arterial hypertension.

The study included 43,197 men aged 40-54 years, of whom 23,378 were in the intervention group and 19,819 in the comparison group; the number of man-years of follow-up totalled for the whole group 177,703. The study proved the efficacy of active, predominantly secondary prevention of arterial hypertension (AH), carried out in men aged 40-54 years over a period of 3-5 years in 12 centres within the framework of the cooperative programme. In comparison with the control group, the following changes were registered in the intervention group: 1) overall mortality decreased by 17.

Risk factors dynamics in multifactorial prevention of ischaemic heart disease.

The effectiveness of preventive measures in populations subjected to a different degree of preventive activity was according to the dynamics of risk factors (RF) tested in the course of four years. Among 6619 examined men aged 40-59 years, a high incidence of RF (79.2%), their connection with ischaemic heart disease (IHD), and frequent simultaneous incidence of several RF even in subjects without IHD were found.

Rhythmic structures of the aorta in children and young adults.

517 samples of the aorta (descending thoracic and abdominal) from children aged 0 to 14 years and 70 men aged 20-29 years were investigated. Rhythmic structures (RS) were found in 4% of still-borns and in children in their first days of life. Thereafter, the occurrence of RS systematically increased with age, and after the first year of life they occurred in 60% of cases.

Beta-blocker action on lymphocyte proliferative response in essential hypertension.

The proliferative response of phytohaemagglutinin (PHA) - stimulated lymphocytes of healthy donors and hypertensive subjects was analysed according to 3H-thymidine incorporation and cell cycle phase position on a flow cytofluorimeter. 3H-thymidine uptake and the percentage of cells in (S + G2) phase were significantly lower in hypertensive patients. After short-term propranolol administration the lymphocyte blastogenic response in essential hypertension increased by 30--100%.

The use of Weibull distribution to describe the in vivo absorption kinetics.

The drug in vivo absorption rate reflects the distribution of drug molecules absorption times. For the latter the Weibull distribution is suggested and some examples taken from the literature are used to support the proposal. Cumulative absorption data for theophylline in man and pantothenic acid in rats are linearized in the double log coordinates, and the Weibull absorption model parameters are estimated by linear regression.