Biomedical subjects

Elier Paz

Publications and source records attributed to Elier Paz.

5 recordsLinked to original sources

PubMed2006

The Mediterranean and CHO diets decrease VCAM-1 and E-selectin expression induced by modified low-density lipoprotein in HUVECs.

BACKGROUND AND AIM: The oxidative modifications of low-density lipoprotein (LDL) are crucial for the atherosclerosis process. The aim of this study was to determine if the minimally modified LDL, obtained after the ingestion of three different diets, produce differential effects on the vascular cell adhesion molecule-1 (VCAM-1) and E-selectin expression in human umbilical endothelial cells (HUVECs). METHODS AND RESULTS: Twenty healthy young males were exposed to three dietary periods. Each period lasted four weeks. During the first period, all subjects consumed a saturated fat (SFA) enriched diet (38% fat, 20% SFA). The second and third dietary periods were administered following a randomized crossover design: a low fat high carbohydrates diet (CHO diet) and a Mediterranean diet. LDL particles, isolated during each dietary period, were oxidized by exposure to UV light and incubated for 48 h with HUVEC. Thereafter, 100 U/mL of TNF-alpha was added and incubation continued for 6 h. Cellular ELISA determined adhesion molecules expression. Lag time, propagation rate and total amounts of formed conjugated dienes were calculated in LDL incubated with 10mumol/L Cu(2+). When compared to the SFA diet, LDL isolated from the Mediterranean and CHO diets induced a lower expression of VCAM-1 and E-selectin in HUVECS (P<0.007). There were no differences between both lipid lowering diets. However, lag time of LDL from the Mediterranean diet was higher than with the CHO diet (P<0.042). This parameter was inversely correlated with E-selectin expression (r=-0.497; P<0.04). CONCLUSION: Our results suggest that both the Mediterranean and CHO diets may decrease the pro-inflammatory environment induced by modified LDL in endothelial cells.

Adult↗

PubMed2004

Effect of simvastatin in familial hypercholesterolemia on the affinity of electronegative low-density lipoprotein subfractions to the low-density lipoprotein receptor.

The effect of simvastatin therapy on the biologic characteristics of the electronegative low-density lipoprotein (LDL) subfraction of patients with familial hypercholesterolemia (FH) was studied. Total LDL, isolated from FH plasma at 0, 3 and 6 months of simvastatin treatment, was subfractionated into electropositive LDL (LDL[+]) and electronegative LDL (LDL[-]) by anion exchange chromatography. LDL isolated from healthy normolipemic (NL) subjects was used as a control. The LDL(-) proportion was twofold higher in patients with FH than in NL subjects (17.6 +/- 1.6% vs 7.8 +/- 1.5%, respectively; p <0.05) and was progressively reduced by simvastatin therapy (15.7 +/- 1.6% at 3 months; 13.8 +/- 2.5% at 6 months; p <0.05). Both LDL subfractions from patients with FH had a higher relative cholesterol content and decreased apolipoprotein B and triglycerides than NL subfractions. Simvastatin progressively induced changes in lipid content of both LDL subfractions in patients with FH, and lipid composition was closer to these subfractions in NL subjects after 6 months of therapy. Binding displacement experiments in human fibroblasts demonstrated that LDL(-) from both groups of subjects had a lower affinity of binding to the LDL receptor that LDL(+). In addition, LDL(+) in patients with FH presented an intermediate binding affinity between LDL(-) and LDL(+) in NL subjects. Simvastatin-induced changes in LDL composition were accompanied by a progressive increase in affinity of LDL(+) and LDL(-) in patients with FH. After 6 months of therapy, LDL(+) in FH had an affinity similar to that of LDL(+) in NL subjects. The LDL(-)-induced release of chemokines interleukin-8 and monocyte chemotactic protein-1 from cultured endothelial cells was twofold higher compared with that of LDL(+). No difference in chemokine release between patients with FH and NL subjects or the effect of simvastatin were observed. We conclude that simvastatin therapy was able to modify LDL subfraction composition in subjects with FH and increase their affinity to the LDL receptor. This improvement could contribute to the observed reduction in LDL(-) proportion induced by simvastatin.

Adult↗

PubMed2004

The influence of lipoprotein lipase gene variation on postprandial lipoprotein metabolism.

Lipoprotein lipase (LPL) is one of the key enzymes in the metabolism of triacylglycerol-rich lipoproteins (TRL). We evaluated whether the association of LPL HindIII (H1/H2) and Serine447-Stop (S447X) polymorphisms may explain the interindividual variability observed during postprandial lipemia. Fifty-one healthy male volunteers (26 with the H2S447 genotype, 15 with the H1X447 genotype, and 10 with the H1S447 genotype) were subjected to a vitamin A-fat load test consisting of 1 g fat/kg body weight and 60,000 IU vitamin A. Blood was drawn every hour until the 6th hour and every 2 h and 30 min until the 11th hour. Data revealed that subjects that are homozygous for the H2 allele (H2H2) showed a higher postprandial response for small TRL, retinyl palmitate (RP), large TRL-RP, large TRL-B48, and small TRL-B48 levels. Furthermore, in the case of the S447X polymorphism, 447Ter carriers had a lower postprandial response for small TRL-RP, large TRL-B48, and small TRL-RP. Subjects with the LPL H2S447 genotype had higher plasma triacylglycerol, large TRL-triacylglycerol, large TRL-RP, small TRL-RP, and large TRL-B48 (P < 0.037) than H1X447 subjects. The modifications observed in postprandial lipoprotein metabolism in young normolipemic males with LPL polymorphism could be involved in the lower risk of coronary artery disease associated with the H1X447 genotype.

Adolescent↗

PubMed2002

Effects of the human apolipoprotein A-I promoter G-A mutation on postprandial lipoprotein metabolism.

BACKGROUND: There is considerable interindividual variability in the postprandial lipid response to a fat-rich meal, and genetic factors have been considered to account for some of these effects. We previously showed that the G-A mutation 5' to the apolipoprotein (apo) A-I gene was significantly associated with the LDL-cholesterol response to diet. OBJECTIVE: We evaluated whether this effect is mediated by mechanisms involving postprandial lipoprotein metabolism. DESIGN: Twenty-eight G/G and 23 G/A healthy male subjects, homozygotes for the apo E3 allele, were subjected to a vitamin A fat-loading test. Blood was drawn at time 0 and every hour for 11 h. RESULTS: There was a significant postprandial decrease in plasma cholesterol, LDL cholesterol, and apo B in G/G subjects but not in G/A subjects. A greater postprandial response in large triacylglycerol-rich lipoproteins (TRLs) and a smaller postprandial response in large TRL apo A-IV was observed in G/A than in G/G subjects. Retinyl palmitate in large and small TRL concentrations was similar for both genotypes. No significant genotype effects were detected for triacylglycerol concentrations in plasma, small TRL fraction, and apo A-I and HDL-cholesterol concentrations. CONCLUSION: Our data suggest that the G-A mutation affects the LDL-cholesterol response to diet by mechanisms involving postprandial lipoprotein cholesterol metabolism.

Adult↗

PubMedDate not supplied

Effects of virgin olive oil phenolic compounds on LDL oxidation and vasorelaxation activity.

This study examined the efficacy of virgin olive oil phenolic extract and other phenolic compounds (oleuropein, caffeic acid) in preventing oxidative modifications of human low density lipoprotein oxidised by CuCl2. The vasorelaxant effect of these compounds on rat aortic ring with and without functional endothelium is also discussed. Olive oil phenolic extract, caffeic acid and oleuropein increased the lag time of conjugated diene formation in a concentration-dependent manner. Moreover, phenolic extract produced a vasorelaxant effect that persisted in denuded aorta and after inhibition of nitric oxide synthase by NG-methyl-L-arginine (L-NMMA) or methylene blue. Oleuropein did not produce a relaxant effect, whereas caffeic acid produced partial relaxation at concentration 0.5 g/L.

Animals↗