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Biomedical subjects

G Sezille

Publications and source records attributed to G Sezille.

At least 19 recordsLinked to original sources
PubMed1983

Changes in the fatty acid patterns of brain phospholipids during development of rats fed peanut or rapeseed oil, taking into account differences between milk and maternal food.

The nature and amount of essential fatty acids in dietary fat play a leading part in the repartition of brain polyunsaturated fatty acids (n-3 and n-6). In order to determine precisely the respective roles of linolenic and linoleic acids in the diet on rat brain development, we used two diets in which the percentage of linolenic acid (18:3 n-3) was different. The animals were fed peanut oil (group A) or rapeseed oil (group B) during pregnancy and throughout lactation. The study of the fatty acid composition of gastric milk showed that the levels of linoleic acid (18:2 n-6) and more so linolenic acid (18:3 n-3) were much lower than in dietary fats. In group B, the 18:3 n-3 level of gastric content was about four times lower (2.4%) than in the maternal diet (8.5%) at the beginning of the suckling period and significantly increased until weaning. Analysis of the fatty acid composition of ethanolamine phosphoglycerides showed that docosapentaenoic acid delta 7-10-13-16-19 (22:5 n-3) and docosahexaenoic acid delta 4-7-10-13-16-19 (22:6 n-3) levels increased in group B in relation to group A and, on the other hand, the docosapentaenoic acid delta 4-7-10-13-16 (22:5 n-6) level decreased in group B. The sum of (n-3 + n-6) fatty acids did not change in either group B or group A. In our experimental conditions, we found no marked effect of diet composition upon conversion of linoleic acid to arachidonic acid. In summary, linolenic acid can be utilized in the brain (rather than linoleic acid) to provide long-chain polyunsaturated fatty acids and the amount of n-3 fatty acids would correlate with the desaturation activity of docosatetraenoic acid delta 7-10-13-16 (22:4 n-6) to docosapentaenoic acid delta 4-7-10-13-16 (22:5 n-6).

Animals↗
PubMed1983

[Effect of the linolenic acid content of the mother's diet on the polyunsaturated fatty acid composition of subcellular fractions in brain development in the rat].

In order to determine precisely the respective roles of linolenic acid and linoleic acid in the maternal diet on rat brain subcellular fractions during development, we used two diets with different percentages of linolenic acid (18:3 n-3). The animals were fed peanut oil (group A) or soybean oil (group B) during pregnancy and throughout lactation. Nature and amount of essential fatty acids had no incidence on saturated and monounsaturated fatty acid distributions in myelin, synaptosomal, mitochondrial and microsomal fractions. In adult rats, all subcellular fractions are marked by an increase of n-3 fatty acid and a decrease of n-6 fatty acid levels in group B compared to group A. In 15-day-old animals, on the contrary, only the synaptosomal fractions are significantly affected by the diet. Independent of diet, brain development is marked by a decrease of n-6 fatty acids in all subcellular fractions; on the other hand, the n-3 fatty acid level is increased in the synaptosomal and mitochondrial fractions, and decrease in the myelin and microsomal fractions. The sum of (n-3 + n-6) fatty acids remains constant in group B and in group A in all subcellular fractions. Finally, under our experimental conditions, we found no marked effect of diet composition upon linoleic acid conversion to arachidonic acid; only the delta 4-7-10-13-16-docosapentaenoic acid (22:5 n-6) level decreased in group B. delta 7-10-13-16-19-Docosapentaenoic acid (22:5 n-3) seemed to be a better substrate for delta 4 desaturase than delta 7-10-13-16-docosatetraenoic acid (22:4 n-6).

Animals↗
PubMed1983

[Platelet aggregation and platelet and plasma fatty acid levels in the child with migraine. Apropos of 40 case reports].

The authors have studied platelet aggregability in the presence of ADP and collagen in a population of 40 migrainous children between migraine attacks. They completed their investigations by a qualitative dosage in platelets and in plasma of fatty acids, precursors of prostaglandins, which are well known for their importance in platelet aggregation and vasculomotor reactions. This study was made in comparison with an equal number of controls chosen from the same age-groups. The authors didn't find the hyperaggregability observed by other authors in grown-up populations. They noticed a light-but statistically significant-diminution of linoleic acid in the platelets and in the plasma. A study based on observations does not entirely confirm for certain an alimentary origin.

Adolescent↗
PubMed1981

[Circadian meal-related changes in serum lipoprotein levels in normal subjects (author's transl)].

Circadian variations in serum lipoprotein levels in relation to meals were investigated in 10 healthy subjects on a normal diet. Lunch and dinner produced a concomitant increase in triglycerides and the apo-B of very low density lipoproteins (d less than 1.006). The increase observed after dinner was of the same degree as after lunch but was more prolonged; this longer duration was unrelated to the nocturnal increase in free fatty acids. Apo-A1 levels also rose slightly after lunch and dinner, and so did HDL-cholesterol which, however, decreased during the night. These results suggest that in normal subjects the intravascular lipolytic activity is reduced during the night.

Adult↗
PubMed1981

[Plasma levels of apoproteins B and A in relation to blood cholesterol and triglycerides. Distribution according to age and sex and influence of various risk factors (author's transl)].

Plasma levels of apoproteins B and A, triglycerides, VLDL + LDL-cholesterol and HDL-cholesterol were simultaneously measured in an ambulatory population of 477 subjects (206 male and 271 female). VLDL + LDL-cholesterol and apo B values were similar in males and females and significantly increased with age. Conversely, HDL-cholesterol and apo A values were higher in females than in males and remained stable with age. HDL-cholesterol and apo A correlated inversely with triglycerides. Overweight, alcohol and smoking introduced significant changes in the parameters studied.

Adolescent↗
PubMed1980

[Serum lipase assay for clinical use. Critical study (author's transl)].

An accurate, quick, and reproducible method to assay serum lipase activity allowed a parallel study of lipase and amylase in 147 patients. Lipase appeared very specific of pancreatic distress. In acute pancreatitis its increase was constant, frank, quick and lasting. It brought a diagnostic argument superior to the dosages of amylase activities in serum and/or urine. But its value as an evolutive and pronostic test was as much limited. Its interest as a negative argument for differential diagnosis was not superior either. In chronic pancreatic diseases, it gave evidence of massive spread or complications.

Abdomen, Acute↗
PubMed1980

Plasma levels of VLDL- + LDL-cholesterol, HDL-cholesterol, triglycerides and apoproteins B and A-I in a healthy population--influence of several risk factors.

Plasma apo B and apo A-I were determined in 477 subjects (206 males and 271 females) by laser immuno-nephelometry. Measurements of VLDL- + LDL-cholesterol, HDL-cholesterol and triglycerides were done simultaneously. VLDL- + LDL-cholesterol and apo B values were similar in males and females and increased with age. HDL-cholesterol and apo A-I values were higher in females but stable with age. Different regression curves (HDL-cholesterol vs apo A-I) were obtained in males and females and a negative correlation was found between HDL-cholesterol or apo A-I and triglycerides. Increased body weight was associated with higher values of VLDL- + LDL-cholesterol, apo B and triglycerides in both sexes but lower values of HDL-cholesterol and apo A-I essentially in males. Finally, the study provides evidence of a relationship between smoking and alcohol consumption on the one hand, and HDL-cholesterol and apo A-I on the other.

Adult↗
PubMed1980

[Relative concentration of VLDL C-apolipoproteins in the hyperlipoproteinaemia of haemodialysis-treated chronic renal failure (author's transl)].

The hypertriglyceridaemia of patients with haemodialysis-treated chronic renal insufficiency was characterized in respect of the apolipoproteins C of VLDL. Using Kane's method, particular attention was paid to the CII/CIII ratio of VLDL isolated by ultracentrifugation in eleven hemodialyzed patients with hypertriglyceridaemia. There was a significant decrease of this ratio compared to twenty three patients with essential hypertriglyceridaemia. A removal defect is suggested as fundamental to the pathogenesis of the hypertriglyceridaemia of renal failure since apoprotein CII acts as a specific activator of lipoprotein lipase.

Humans↗
PubMed1979

Immunochemical determination of human apolipoprotein B by laser nephelometry.

The Hyland laser nephelometer PDQ system for the assay of apolipoprotein B (apo-B) in human serum is described. Within and between-batch precision, accuracy and reliability are discussed. This instrument represents an important development in the immunochemical assay of apo-B, and the speed, precision, and convenience of the methodology make such a system attractive. Quantitation of apo-B was assessed in normal and hyperlipaemic subjects. Comparisons were made with two other specific and sensitive immunological methods for quantifying apo-B: enzymeimmunoassay (EIA) and rocket immunoelectrophoresis (RIE). Results obtained by the three methods correlated very well.

Apolipoproteins↗
PubMed1979

[Lipoprotein electrophoresis on acrylamide-agarose plates, with discontinuous acrylamide gradient].

We describe a modified lipoprotein electrophoresis on acrylamide gel. The lipoproteins, prestained with Sudan Black, are separated by running on acrylamide-agarose gels, with two different concentrations of acrylamide and a constant concentration of agarose. The sera are deposited in the first gel (2% acrylamide). Chylomicrons remain at origin and other lipoproteins run through the first gel to the second one (3% acrylamide gel). VLDL stays at the junction of both gels, LDL and HDL are separated in the 3% acrylamide gel. By this technique, we were able to detect an increase of Lp(a) and to identify the different types of hyperlipoproteinemia. After running, the plates can be treated for storage.

Electrophoresis, Agar Gel↗
PubMed1979

[Diagnosis of type III hyperlipoproteinemia: contribution of an air-driven ultracentrifuge associated with an original tube-slicer (author's transl].

Diagnosis of type III hyperlipoproteinemia requires preparative ultracentrifugation in order to measure the cholesterol/triglyceride molar ratio into isolated d less than 1.006 lipoproteins. The authors describe an ultracentrifugation micromethod which needs 600 microliter of serum and can be completed within three hours (Airfuge Beckman instruments). An original tube-slicer allows the separation of the d less than 1.006 lipoproteins located into top fractions. This simple micromethod might confirm diagnosis of type III in patients and would be useful for clinical laboratories.

Cholesterol↗
PubMed1979

Determination of amniotic fluid phospholipids by thin-layer chromatography, with use of a hydrogen flame ionization detector.

We describe a new specific method for measuring lecithin, sphingomyelin, and phosphatidylglycerol in amniotic fluid by thin-layer chromatography, with use of a hydrogen flame ionization detector. After extraction and acetone precipitation to isolate surface-active lecithin, the phospholipids are separated on a thin rod of refractory and chemically stable material, having an outer coating of a bonded, sintered partition medium. Two solvent systems are used to develop the chromatograms, chloroform/methanol/water to separate lecithin and sphingomyelin, tetrahydrofuran/methylal/methanol for phosphatidylglycerol. Then the rod is passed through an hydrogen flame; the resulting ions produced generate a current, which is amplified and fed to a potentiometric recorder. The height of integral curves was proportional to the area under each peak. For quantitation we used an internal standard (lysolecithin in the first system. phosphatidyldimethylethanolamine in the second). The method requires less than 5 mL of amniotic fluid; results are available within 6 h.

Amniotic Fluid↗
PubMed1978

Changes in fatty acid composition of cardiac mitochondrial phospholipids in rats fed rapeseed oil.

Male Wistar rats were fed rapeseed oil containing high or low levels or erucic acid for 20 weeks, and changes in the fatty acid composition of cardiac mitochondrial phospholipids were studied. Treatment with rapeseed oil containing 46.2% erucic acid showed incorporation of 22:1 (5.6%) into isolated cardiolipin from heart mitochondria. After high or low (3.7%) erucic rapeseed oil feeding, linolenic acid was slightly incorporated into cardiolipin. Moreover, both of these rapeseed oils induced a significant increase of linoleate-arachidonate ratio in phosphatidylethanolamine and phosphatidylcholine. This ratio was also significantly increased in fatty acids esterified to the beta-position of these phospholipids. On the basis of such results, we have to consider the role of linolenic acid which is present at a high level in the different rapeseed oils used, as a possible inhibitor of heart microsomal enzymes involved in linoleate arachidonate conversion. Such alterations might account for mitochondrial fragility and myocardial lesions obtained in long term rapeseed oil feeding experiments.

Animals↗
PubMed1978

Inhibition enzyme immunoassay, application to human apolipoprotein B.

Inhibition enzyme immunoassay was applied to human apolipoprotein B (apo-B) from plasma. The technical conditions of the assay were determined. The detection limits of the assay were 200 ng to 10 microgram/ml. Correlation coefficients obtained between enzymoassay and rocket immunoelectrophoresis on one hand and radial immunodiffusion on the other were respectively 0.84 and 0.80. The inhibition enzymoassay provides a specific and highly sensitive method for the quantitation of apo-B.

Antibodies↗