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Biomedical subjects

A Mebazaa

Publications and source records attributed to A Mebazaa.

72 records · Page 4Linked to original sources
PubMedDate not supplied

The cardiac endothelium: cardioactive mediators.

Endothelial cells within the heart release a number of substances that modulate myocardial contractile function. These agents include nitric oxide, endothelin, prostanoids, adenylpurines, and other substances that have so far been characterized only in bioassay studies. A notable feature of many of these agents is that they influence contractile behavior predominantly by modifying cardiac myofilament properties rather than altering cytosolic Ca2+ transients. A consequence of this subcellular action is often a disproportionate effect on myocardial relaxation and diastolic tone. The paracrine modulation of cardiac myocyte function by endothelial cell factors is likely to be an important mechanism contributing to the overall regulation of cardiac contractile function, both physiologically and in pathological states.

Animals↗
PubMedDate not supplied

[VNTR3' polymorphism of apoliproprotein B gene in obese people].

Apolipoprotein B (apo B) is the major component of LDL, VLDL and chylomicrons. Variations of lipid concentrations in obese people result from obesity, nutritional and genetic factors. Many genetic polymorphisms of the apo B have been described, associated with variation of lipid concentrations. The aim of the present study was to assess the effect of VNTR3' polymorphism of the apoB gene on lipid and lipoprotein concentrations in overweight subjects. 234 unrelated outpatients (160 women and 74 men, aged 39.3 y 10.5; BMI: 32.8 kg/m2 4.7) were recruited. Using the polymerase chain reaction followed by electrophoresis in polyacrylamide gels, 15 different alleles have been identified. Among them four have been observed less than 5 times in our study. Alleles with 21, 25, 35 and 42 repeats have been observed once. The most frequent is VNTR36 allele (38%), followed by alleles 34, 30, 48, and 46 repeats whose frequencies are 20, 9, 8, and 7% respectively. The possible association between alleles of the VNTR3' of the apoB and anthroprometric and lipid variables was examined. Subjects with 50 repeat allele had significantly higher BMI, and subjects with 32 repeat allele had significantly higher HDL-C and ApoAI levels. Our study confirms in the obese subjects, results published in the general litterature, and shows that the apoB has an important role in the metabolism of plasma lipids and most particulary its gene variants.

Adult↗
PubMedDate not supplied

[Polymorphism insertion/deletion of apolipoprotein B gene: effect on lipid levels in obese patients].

Apolipoprotein B (apoB) is the major proteic component of LDL, VLDL and chylomicrons. Numerous polymorphisms of the apolipoprotein B gene have been described. Particularly, a polymorphism of insertion/deletion located in the coding part of the signal peptide of apoB, associated with modifications of lipid concentrations and the risk of cardiovascular disease, has been reported in the general population. Since obesity is frequently associated with dyslipidemias, the aim of our study was to assess the effect of the insertion/deletion polymorphism of the apolipoprotein B gene on lipid levels in obese subjects. 234 unrelated caucasian obese subjects (74 men and 160 women, aged 39.3 +/- 10.5, BMI : 32.8 +/- 4.7) were recruited. The insertion/deletion polymorphism was determined by electrophoresis in polyacrylamide gels after PCR amplification. The relative frequencies of the Ins and Del alleles were 0.71 and 0.29 respectively. These frequencies were similar to those found in other Caucasian populations. In the whole population, individuals with the Del/Del genotype had significantly higher total-cholesterol to HDL-cholesterol ratios (p = 0.004), LDL-cholesterol to HDL-cholesterol ratios (p = 0.01) and TG-VLDL levels (p < 0.05). They also showed a tendency for higher triglyceride levels (p = 0.09) and lower HDL-cholesterol, apolipoprotein AI and LpAI levels. The allele deletion results in the absence of three amino acids (Leu-Ala-Leu) in the signal peptide of apo B. In the obese people, these structural changes may have some effect on lipid metabolism and cause variation in serum lipid concentrations.

Adult↗