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Biomedical subjects

H Parra

Publications and source records attributed to H Parra.

12 recordsLinked to original sources
PubMed2000

Probucol promotes reverse cholesterol transport in heterozygous familial hypercholesterolemia. Effects on apolipoprotein AI-containing lipoprotein particles.

In order to investigate the effect of Probucol therapy on reverse cholesterol transport, apo AI-containing lipoprotein particles were isolated and characterized, and their cholesterol effluxing capacity and LCAT activity were assayed in four familial hypercholesterolemia patients before and after 12 weeks of Probucol therapy. Four major subpopulations of apo A-containing lipoprotein particles are separated before and after drug treatment; LpAI, LpAI:AII, LpAIV, LpAI:AIV:AII. Probucol reduces both total plasma and LDL-cholesterol (-17 and -14%, respectively). Apo B decreases slightly (-7.6%). Plasma HDL-cholesterol and apo AI decrease by 36.6 and 34.7%. LpA-I showed a marked decrease (-46%). Moreover, plasma LCAT and CETP activities were markedly increased under Probucol treatment. Analysis of lipoprotein particles showed that Probucol induces a decrease of protein content and an increase of cholesterol and triglycerides contents. Interestingly, Probucol induces an enhancement of LCAT activity in LpAI (4.5-fold). This drug induces a trend toward greater cholesterol efflux from cholesterol-preloaded adipose cells promoted by Lp AI and Lp AIV but not by Lp AI:AII. This study confirms the hypothesis, in addition to the lowering LDL-cholesterol levels and antioxidant effects of Probucol, that HDL reduction was not an atherogenic change in HDL system but may cause an antiatherogenic action by accelerating cholesterol transport through HDL system, promoting reverse cholesterol transport from peripheral tissues.

Adipocytes↗
PubMed1985

Latex immunoassay of human serum Lp(a+) lipoprotein.

A sensitive latex immunoassay for human serum lipoprotein Lp(a+) is based on direct agglutination by Lp(a+) of latex particles coated with specific antibody. The agglutination is quantified by turbidimetry using a photometer at 360 nm. The stabilization of antibody-coated latex particles by bovine serum albumin occurs under well-defined conditions (pH, concentration of bovine serum albumin, and antibody loading of latex particles). The standard curve of serum lipoprotein Lp(a+) ranges from 0.05 to 1.15 mg/l. Inter- and intra-assay coefficients of variation were less than 8% and 3%, respectively. Results were well correlated with those obtained by electroimmunodiffusion (r = 0.98, n = 108).

Humans↗
PubMed1984

[Assay of serum apolipoprotein A-II by electro-immunodiffusion on ready-for-use plates. Clinical applications].

Few papers have been devoted to the study of apolipoprotein A-II (apo A-II), one of the major peptides contained in HDL, probably because of the methodological difficulties associated with its assay. The aim of this study is to provide the clinical biochemist with a simply easy to use assay technique. We have been able to demonstrate the practical value of apo A-II assay in hepatology and in the detection of excessive drinkers. On the other hand, our results indicate that apo A-II is not a parameter of choice for the detection of coronary atherosclerosis.

Adult↗
PubMed1982

[Plasma lipoproteins and apolipoproteins. Value of their determination in the detection of coronary atherosclerosis. Comparison with data supplied by coronarography].

Plasma lipids, lipoproteins and apolipoproteins A1 and B were determined in a reference population and in 273 patients who underwent coronary arteriography for evaluation of chest pain. The patients were divided into 3 groups according to arteriographic findings. The 102 patients in group A had normal coronary arteries; the 30 patients in group B had small vascular abnormalities but no significant narrowing; the 141 patients in group C had significant vascular lesions with greater than or equal to 50% narrowing. Total cholesterol and triglycerides were quantified using enzymatic methods. HDL cholesterol and phospholipids were enzymatically analyzed after phosphotungstate precipitation. Plasma lipoproteins were evaluated by quantitative electrophoresis based on densitometric scanning of the lipoprotein bands after separation and visualization by polyanion precipitation. Apoproteins A1 and B were measured by electroimmuno-diffusion assay using ready-for-use plates. Statistical evaluation of the data showed that group C patients had higher betalipoprotein and apo B levels and lower alphalipoprotein and apo A1 levels than subjects with normal coronary arteries. The predictive value of these results was established in relation to clinical findings. Plasma lipid measurements proved inadequate to separate the 3 groups. In contrast, the betalipoprotein/alphalipoprotein ratio and, still better, the apo A1/apo B ratio provided good discrimination. The results suggest that measurement of plasma apo A1 and apo B levels is the best means of assessing the risk of coronary artery disease.

Adult↗
PubMedDate not supplied

Attachment and quality of life in older, community-residing men.

The purpose of this study was to determine the extent to which demographic variables and attachment predicted quality of life in community-dwelling older men. The subjects were 100 men aged 58 to 84 (M = 68.4). Hierarchical regression revealed that two demographic variables, plus the attachment variable, accounted for 30% of the variance in predicting quality of life. Having no limiting health condition accounted for 17% of the variance, while education accounted for an additional 5% of the variance. The attachment total score accounted for an additional 8% of the variance in predicting quality of life.

Aged↗