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Biomedical subjects

G Sezille

Publications and source records attributed to G Sezille.

At least 37 records · Page 2Linked to original sources
PubMed1978

Enzyme immunoassay for human apolipoprotein B, the major protein moiety in low-density- and very-low-density lipoproteins.

We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to human apolipoprotein B were incubated with the solid-phase lipoprotein B. Soluble antigen competed with solid-phase antigen for binding to antibodies. After washing, peroxidase-labeled sheep antibodies against rabbit immunoglobulins were added, and after further washing the bound label was assayed. This provided a direct measurement of the soluble antigen. The best technical conditions for the assay were determined. The minimum detectable concentration was 1 microgram per assay. The enzyme immunoassay yielded values that compare favorably with those obtained by radial immunodiffusion (r = 0.84) and by rocket immunoelectrophoresis (r = 0.80). The assay offers several advantages over existing techniques: sensitivity, specificity, simplicity, ane non-use of radioisotopes.

Apolipoproteins↗
PubMed1978

[Adipocyte size in primary hypertriglyceridemia with and without obesity (author's transl)].

Adipose tissue cellularity of patients with endogenous hypertriglyceridemia whether associated with obesity or not has been studied by means of a semiautomatic method of counting and sizing osmium tetroxide fixed adipocytes. Cell population distributions were analyzed by mathematical computation. The Coulter Counter system was able to determine mean diameter (or volume) and cell size dispersion which defined adipocyte population. An overall shift of cell population size has been found to characterize adipose tissue cellularity of the different groups examined. Adipocyte population in the obese was defined by increased fat cell size with overlapping distributions between both groups of same weight. Nevertheless normolipemic obese patients were characterized by larger cell size than hypertriglyceridemic subjects matched for adiposity index. The results are discussed in relation to the removal defect found in endogenous hypertriglyceridemia.

Adipose Tissue↗
PubMed1977

[Exact determination of the lecithin/sphingomyelin ratio in amniotic fluid. Suggestion of a reference methods (author's transl)].

Pulmonary maturity of the fetus can be evaluated by the lecithin/sphingomyelin (L/S) ratio in amniotic fluid. To existing methods of lipid extraction, precipitation with acetone and chromatography, we add a simple and accurate estimation of sphingomyelins (S) and precipitated lecithins (Lp) without acid digestion. The method is reproducible (C.V. less than 9%) for the measurement of Lp/S ratio and gives with accuracy the concentrations of Lp, avoiding possible errors in interpretation of Lp/S. Our results show that at 35 weeks of normal gestation, Lp/S ratio is about 2 and Lp concentration, 10 mg/1.

Amniotic Fluid↗
PubMed1977

Changes in rat heart phospholipid composition after rapeseed oil feeding.

The influence of long duration rapeseed oil feeding with high or low levels of erucic acid has been investigated on rat heart phospholipids. The rats treated for 20 wk with rapeseed oil containing 46.2% erucic acid showed a twofold increase in the sphingomyelin content of the heart. Treatment with primor rapeseed oil (3.7% erucic acid) for 20 wk did not modify phospholipid composition of rat heart. The fatty acid patterns of phosphatidylethanolamine and phosphatidylcholine were slightly influenced by the high erucic rapeseed oil; eicosenoic acid was incorporated preferentially into position one, but erucic acid showed a random distribution in both. After high erucic rapeseed oil feeding, 22:1 was incorporated into cardiolipin (5.6%) and sphingomyelin (10.5%). The incorporation of 22:1 into sphingomyelin was associated with an increase of the percentage of 24:1 (14.6%) and a decrease of saturated long chain fatty acid (22:0, 24:0) percentages. Primor rapeseed oil caused a slight increase of 24:1 and a decrease of 22:0 and 24:0 in rat heart sphingomyelin. As cardiolipin is localized in the inner membrane of mitochondria and sphingomyelin in plasma and microsomal membranes, the acyl-moiety alterations of both phospholipids might be correlated to the pathological lesions of rat heart after a long duration of rapeseed oil feeding.

Animals↗
PubMed1977

[Lipid composition of circulating lipoproteins in various types of hyperlipoproteinemia (author's transl)].

By means of simple and selective precipitation methods with polyanions, three lipoprotein fractions rich in HDL (F1), LDL (F2) and VLDL (F3) were isolated from serum of normal subjects, of normolipemic patients with atherosclerotic disease and of patients with type IIA, IIB or IV hyperlipoproteinemia. Cholesterol content was used to quantify lipoprotein fractions and to measure relative triglycerides abundance (cholesterol/triglyceride ratio and regression coefficients). Findings in the atheroscerotic patients without hyperlipoproteinemia resembled those of the controls. No correlation between cholesterol and triglycerides was obtained in F1 of the various groups. However, a significant relation was established in F2 and the relative content of triglycerides was increased progressively from type IIA, through type IIB to type IV. In all types of hyperlipoproteinemia comparable relationships were found in F3 mainly containing VLDL, the precursor of LDL. In fractions F2 and F3, types IIB and IV were clearly distinguishable from type IIA.

Adult↗
PubMed1977

[Detection of a new lipoprotein: Lp(a). Its occurrence in atherosclerosis with or without hyperlipemia].

Detected using a method involving gradient electrophoresis on polyacrylamide gel, the presence of a high level of an Lp(a) was demonstrated in 17% of control subjects and 39% oh hyperlipidaemic subjects explored. The difference appeared to be particularly significant in subjects with a pure hypercholesterolaemia (type IIA) or dominant hypercholesterolaemia (type IIB), which may be accounted for by the antigenic communities and related substances in the lipid composition uniting Lp(a) to LDL. The association of frank atherosclerosis with the hyperlipidaemia substantially increased the frequency of high levels of circulating Lp(a). A combined elevation of levels of Lp(a) and LDL would seem to be associated with a particular atherogenic power.

Arteriosclerosis↗
PubMed1976

[Analysis of lipoproteins using polyacrylamide gel electrophoresis and fractionated precipitation with polyanions and detergents. Use in the classification of hyperlipoproteinemias].

Sodium dodecylsulphate precipitates very low density lipoproteins (VLDL and chylomicrons) rich in triglyceride and a narrow correlation (r = 0.9) was found between the turbidimetric index SDS and triglyceridemia. Heparin in calcium medium acts in the same way and precipitates also low density lipoproteins (LDL) rich in cholesterol. A correlation (r = 0.875) was drawn up between the cholesterol LDL and the difference between the turbidimetric indices (heparin Ca -- SDS). In the first case, we were thus measuring by turbidimetry a VLDL + chylomicron index and, in the second case, an LDL index which permits one to obtain simplified typing of the hyperlipoproteinemias. A nomogram linking the two indices of hyperlipoproteinemia type was drawn up experimentally. This orientation analysis may be completed by electrophoresis on polyacrylamide gel used in concentration gradient and pH. In the system proposed, the lipoproteins were previously stained with tetrazolium nitroblue and clearly shown up. The chylomicrons in particular, become separated from the VLDL, the sinking pre-beta-lipoprotein or Lp (a) was identifiable and the type III hyperlipemia was easily diagnosed.

Adolescent↗
PubMed1976

[Effect of clofibrate on tissue lipase activity in rats].

Given for 20 days at a concentration of 0.3% in the diet, clofibrate lowers serum triglyceride level and causes a 48% increase of lipoprotein lipase activity in rat fat pad, after feeding. This increase does not appear in the animals on fasting. These results agree with an effect of clofibrate upon membranous adenyl-cyclase of adipose tissue.

Adenylyl Cyclase Inhibitors↗
PubMed1976

[Studies of lipoprotein lipase activity and adipocyte characteristics in the human: effect of obesity and diabetes (author's transl)].

Adipose tissue lipoprotein lipase activity (LPLA) and cellularity have been studied in controls, in diabetic or non-diabetic obese subjects and in insulin dependent diabetic patients. LPLA is increased in diabetic or non-diabetic obese subjects and in insulin dependent diabetic patients. LPLA is increased in diabetic or non-diabetic obese subjects (p less than 0.02) and decreased in insulin dependent diabetic patients (p less than 0.02). Adipocyte size is larger in obese subjects, whether diabetic or not (p less than 0.05). As defined by LPLA and cell size means, the different groups are related linearly. The implications of this relationship between LPLA and adipocyte size are considered.

Adipose Tissue↗
PubMed1975

Improved serum lipoprotein electrophoresis procedure in polyacrylamide gradient gel.

A method based based upon polyacrylamide gradient gel for the electrophoretic separation of lipoproteins prestained with the diformazan of nitroblue tetrazolium is described and evaluated. It gives accurate characterization of the different lipoproteins, good separation between chylomicrons and very low density lipoproteins and can be also applied to the diagnosis of type III hyperlipoproteinemia without need for ultracentrifugation.

Electrophoresis, Polyacrylamide Gel↗