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Biomedical subjects

N V Perova

Publications and source records attributed to N V Perova.

At least 91 records · Page 5Linked to original sources
PubMed1990

[The effect of a diet enriched with omega-3 polyunsaturated fatty acids on thrombocyte functional activity and on the blood lipid-apolipoprotein spectrum in newly occurring stenocardia].

The diet enriched with omega-3 polyunsaturated fatty acids (5 g/day for 4 weeks) was applied to the treatment of patients (n-22) with angina pectoris occurring for the first time. Meanwhile 6 patients received the control diet similar to the fish one as regards the protein, fat, carbohydrate, cholesterol and caloric ratio. The control group patients showed no alterations in blood lipids and apoproteins of in platelet function. The patients who received the fish diet manifested an appreciable decrease in the concentration of triglycerides (p less than 0.01), a slight reduction of cholesterol content. The level of high density cholesterol remained unchanged. There was a decrease in the concentration of thromboxane (p less than 0.05) and in the platelet count (p less than 0.05). In some patients, individual reactions of ADP-induced platelet aggregation were revealed: from the lowering (-60-10%) seen in the third of the examined up to the rise (+10+90%) in the other third. The decrease of apoprotein A1 established as safe for the protective cholesterol-transport properties of high-density lipoproteins was established.

Adult↗
PubMed1990

[Study of in vitro thromboxane A2 generation by platelets of patients with first-time appearing angina pectoris under the effect of fish diet].

Thromboxane A2 (TxA2) is a pathogenic factor as it stimulates thrombogenesis and causes vasospastic reactions typical of coronary heart disease. The eicosapentaenic acid (EPA)-rich diet containing precursors of inactive TxA2 synthesis and the routine hospital diet (No. 10 according to Pevzner) were examined for effects on platelet generation of TxA2 on induction of ADP aggregation in 12 patients with first angina (FA). In patients with FA keeping diet No. 10, the platelets were found to be able to generate TxA2 under the influence of ADP, while in those on EPA-rich diet, the latter failed to exhibit this capacity. It was suggested that the EPA-containing fish diet might affect platelet aggregation favourably, which followed from the evidence for decreased pathogenic TxA2 generation in the aggregated platelets from FA patients and a lower risk of vascular spasms.

Adult↗
PubMed1989

Number of glucocorticoid receptors in lymphocytes and their sensitivity to hormone action.

The study demonstrated a decreased level of glucocorticoid receptors (GR) in peripheral blood lymphocytes from hypercholesterolemic subjects, and an elevated level in patients with acute myocardial infarction. In the lymphocytes with a high GR number, dexamethasone inhibited [3H]-thymidine and [3H]-acetate incorporation into DNA and cholesterol, respectively, in the same manner as in the control cells. On the other hand, a decreased GR number resulted in a less efficient dexamethasone inhibition of the incorporation of labeled compounds. These data showed that the sensitivity of lymphocytes to glucocorticoids changed only with a decrease of GR level.

Adult↗
PubMed1989

Topo-dynamic characteristics of human plasma VLDL apolipoproteins and efficiency of triacylglycerol hydrolysis by lipoprotein lipase.

A lower accessibility to water-soluble quenchers of tryptophanyls of VLDL apolipoproteins B, E, C as compared to LDL apoB chromophores has been detected by a fluorescence quenching technique. The dynamic behaviour of the tryptophanyls of VLDL amphipathic apolipoproteins E and C did not change in the presence of a detergent, Tween-20, at sub-lytic concentrations. However, a reversible structural transition registered by the 'red' shift of the emission spectrum maximum and the changes in the quenching pattern by I- occurred under these conditions. The increase in the VLDL tryptophanyl accessibility to acrylamide and the decrease in the quenching constant were observed at partial and complete solubilization of the VLDL particles by the detergent. Dissociation of apolipoproteins from VLDL occurred after their treatment with Tween-20 or lipoprotein lipase isolated from bovine milk, and the tryptophanyl population not participating in fluorescence energy transfer on lipid phase-localized fluorescent probe pyrene appeared. In the presence of Tween-20, the relative affinity of apoE for the lipid matrix of VLDL was lower than that of apoC. Besides, the uncompetitive mode of inhibition of the LPL activity by apoC-III has been demonstrated. It is suggested that: (1) the amphipathic apolipoproteins E and C are organized as clusters on the VLDL surface and/or partially shielded by apolipoprotein B: (2) self-regulation of lypolysis may exist involving detergent-like reaction product accumulation and changes in relative apolipoprotein contents.

Animals↗
PubMed1989

VLDL substrate properties and efficiency of their metabolic transformation by LPL.

A study was made of the regulation of the triglyceride hydrolysis catalysed by LPL from bovine milk, by the apoproteins from human plasma VLDL. Both isolated apolipoproteins, and those found on the surface of plasma VLDL particles, were investigated. A concentration-dependent activating action of apo C-II on the hydrolysis of emulsified triolein, and uncompetitive inhibition of VLDL triglyceride hydrolysis by apo C-III were found. It is suggested that VLDL lipolysis might be controlled in vivo through the variation of the relative surface content of these enzymatic activity modulators.

Animals↗
PubMed1989

Low-density lipoproteins isolated from the blood of patients with coronary heart disease induce the accumulation of lipids in human aortic cells.

Smooth muscle cells cultured from the intima of unaffected human aorta accumulate lipids during incubation with the blood serum of patients with coronary heart disease (CHD). Blood sera of most healthy subjects fail to induce the deposition of lipids in cultured cells. Very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins of two subclasses (HDL2 and HDL3) were isolated from the blood of healthy subjects and CHD patients. LDL from the blood of healthy individuals did not raise intracellular lipid levels within 24 hr of cultivation (the maximal concentration used, 1000 micrograms/ml). During the same incubation period, LDL obtained from the blood of CHD patients (200 to 1000 micrograms/ml) caused a 2- to 5-fold rise in cholesteryl esters as well as a 1.5- to 3-fold rise in free cholesterol and triglycerides, whereas intracellular phospholipid levels remained unchanged. There was a direct correlation (r = 0.95) between cholesterol accumulation in the cells incubated with whole sera of CHD patients and cholesterol level in the cells incubated with LDL isolated from these sera. In one of the three cases, the ability to raise the intracellular level of cholesteryl esters was demonstrated by VLDL (500 micrograms/ml) derived from CHD patients' blood. HDL2 and HDL3 did not affect lipid levels in smooth muscle cells cultured from unaffected intima. HDL3 from the blood of CHD patients and healthy subjects (50 to 250 micrograms/ml) reduced cholesteryl ester levels in cells cultured from atherosclerotic plaques 1.5- to 2-fold. HDL2 also decreased the content of cholesteryl esters in plaque cells, though less effectively than HDL3. The data obtained suggest that circulating LDL and, possibly, VLDL in the blood of CHD patients are capable of inducing the accumulation of fat in vascular wall cells.

Adult↗
PubMed1989

Peritoneal macrophages: a model for detecting atherogenic potential in patients' blood serum.

Human and mouse peritoneal macrophages cultured in the presence of the blood serum of patients with documented coronary heart disease showed a 2- to 3-fold rise in levels of intracellular cholesterol ester and a 1.5- to 2-fold increase in those of free cholesterol and triglycerides. This effect was observed in 83% of cases, whereas the serum of healthy subjects induced the accumulation of lipids in macrophages only in 28% of cases. These data accord with previously published observations obtained on smooth muscle cells of human aortic intima. A direct correlation was found between the accumulation of cholesterol in macrophages and in cultured smooth muscle cells of human aortic intima. The accumulation of lipids in macrophages was dose dependent and increased with time. It is assumed that a culture of peritoneal macrophages may serve as a model for identifying an atherogenic potential of patients' blood serum.

Adult↗
PubMed1989

A biochemical approach to essential hypertension.

Using multivariate statistical analysis, an attempt has been made to select hypertensive and normotensive sub-groups of subjects on the basis of certain parameters of their blood serum, such as the inhibition of purified Na,K-ATPase by serum and the content of two proteins with molecular masses of 12 and 15 kDa. An analysis of 20 human beings (10 hypertensive and 10 normotensive individuals) revealed that the best division into sub-groups is achieved only through the use of a combination of these three parameters.

Adolescent↗
PubMed1989

[Subfractionated conversions of high density lipoproteins in vitro in sera with various lipid spectra].

Using gradient gel electrophoresis, the interconversions of high density lipoproteins (HDL) upon heating for 24 hours at 37 degrees C of blood sera obtained from dyslipidemic patients, were studied. It was shown that during incubation of normolipidemic, hypercholesterolemic and hyperalphacholesterolemic sera, the portion of large particles of HDL2 subclass (HDL2b) is increased with a simultaneous decrease in the portion of the smallest particles of HDL3 subclass (HDL3b and HDL3c). Contrariwise, in hypertriglyceridemic and hypoalphacholesterolemic sera the portion of the largest HDL2b particles is decreased, while that of middle-sized HDL3a is increased. Hence, hypertriglyceridemia and hypoalphacholesterolemia are not associated with an intensive conversion of small HDL3 particles into large HDL2 ones, which may be the reason for the decreased cholesterol transport function of HDL.

Cholesterol↗
PubMed1989

Epidemiology of atherogenic dyslipoproteinaemias in pubertal children (a prospective study).

The study presents the results of a two-year prospective study of a random representative sample of 772 Moscow pupils, aged 10-13 years. Response rate at entry was 95%, one year later--83%, and 80% two years later. The epidemiological situation regarding various atherogenic dyslipoproteinaemias in pubertal children was studied. The most threatening, i.e., stable dyslipoproteinaemias were detected most often in children with an increased number of risk factors of ischaemic heart disease. Dyslipoproteinaemia stabilization is affected mainly by physical and sexual development of children and their physical activity. These findings can be used for targeted non-medicamentous prevention in pubertal children.

Adolescent↗
PubMed1989

[Dynamics of blood lipoprotein and apolipoprotein spectra in patients with unstable angina syndrome during a 1-year follow-up].

During one-year follow-up, plasma lipoprotein (Lp), and apolipoprotein (apo) spectra were studied in 119 patients with unstable angina (UA). Total lipids, cholesterol, various Lps, and apolipoproteins (apo B and apo AI) were examined in the plasma. The patients with UA showed more profound shifts in the spectrum of plasma apolipoproteins. In the patients, high density lipoprotein cholesterol levels below 37-38 mg/dl and an apo B/apo AI ratio over 1.7-1.9 were found to be a sign of high risk for myocardial infarction. It was ascertained that a relationship existed between the clinical course of the disease and changes in the plasma Lp and apolipoprotein spectra in the patients who failed to develop myocardial infarction over the one-year follow-up. During a year, increased "atherogenic" changes in the spectrum of Lp, apo were revealed in patients with a more severe clinical course of the disease as compared to an "instability" period; when the disease proceeded favourably, a "positive" time-course of these parameters was observed.

Adult↗
PubMed1989

[Atherogenic properties of sera from patients with ischemic heart disease demonstrated in vitro].

The sera of coronary patients with angiographically-documented stenosis of 1 to 3 coronary arteries caused a two-to-fivefold accumulation of intracellular cholesterol in intact human aortic intimal cell culture. This property, qualified as "atherogenic", was exhibited by the sera of 90% of the coronary patients examined (97 males and females, aged 29 to 55 years). Only 20% of normal subjects revealed atherogenic properties in cell cultures. The capacity of the sera to accumulate intracellular cholesterol was unrelated to the levels of total cholesterol, high density lipoprotein cholesterol, apo-B or apo-AI, taken separately, but showed a weak correlation to the apo-B/apo-AI ratio. The sera of coronary patients caused lipid accumulation in human aortic medial smooth-muscle cells and blood mononuclear cells, in human and mouse peritoneal macrophages, but never in human aortic or umbilical vein endothelial cells, nor human embryo fibroblasts.

Adult↗