Increased oxidized low density lipoprotein associated with high ceruloplasmin activity in patients with active acromegaly.

OBJECTIVE: Active acromegaly is associated with increased mortality from cardiovascular causes. Several studies have shown increased atherogenic risk factors and biomarkers of inflammation and atherosclerosis in association with growth hormone excess. The aim of this study was to evaluate oxidized low density lipoprotein (oxLDL) levels and some modulators of LDL oxidative modification in patients with acromegaly. DESIGN: Open transversal study. PATIENTS: Fifteen patients with active acromegaly and 15 controls were studied. MEASUREMENTS: We evaluated the levels of oxLDL, thiobarbituric acid reactive substances (TBARS), ceruloplasmin, bilirubin, uric acid and total reactive antioxidant potential, and the activities of ceruloplasmin, myeloperoxidase, superoxide distmutase, paraoxonase 1, and platelet activating factor acethylhydrolase. Statistical analysis was performed including body mass index as a covariate or as a fixed variable. RESULTS: Patients with acromegaly showed significantly higher levels of oxLDL (120 +/- 19 vs. 86 +/- 20 U/l, P < 0.001) and endothelin (P < 0.05), increased ceruloplasmin activity (P < 0.01) and a trend towards higher values in TBARS concentration (P = 0.07) in comparison to healthy controls. OxLDL was positively associated with GH, IGF-I and its binding protein 3 (r = 0.63, P < 0.001; r = 0.53, P < 0.01; and r = 0.56, P < 0.01; respectively). OxLDL showed direct associations with endothelin-1 (r = 0.53, P < 0.01) and ceruloplasmin activity (r = 0.43, P < 0.05). The other parameters evaluated were similar in both groups. CONCLUSIONS: The increase in plasma oxLDL levels, a direct marker of the plaque formation, could constitute a link between atherosclerosis and active acromegaly. LDL oxidation would not be the consequence of diminished antioxidant defences, but of an enhancement in prooxidant factors like ceruloplasmin.

Repeated, but not single, VEGF gene transfer affords protection against ischemic muscle lesions in rabbits with hindlimb ischemia.

Vascular endothelial growth factor (VEGF) gene transfer-mediated angiogenesis has been proposed for peripheral artery disease. However, protocols using single administration have shown little benefit. Given that the transient nature of VEGF gene expression provokes instability of neovasculature, we hypothesized that repeated administration would provide efficient tissue protection. We thus compared single vs repeated transfection in a rabbit model of hindlimb ischemia by injecting a plasmid encoding human VEGF165 (pVEGF165) at 7 (GI, n=10) or 7 and 21 (GII, n=10) days after surgery. Placebo animals (GIII, n=10) received empty plasmid. Fifty days after surgery, single and repeated administration similarly increased saphenous peak flow velocity and quantity of angiographically visible collaterals. However, microvasculature increased only with repeated transfection: capillary density was 49.4+/-15.4 capillaries per 100 myocytes in GI, 84.6+/-14.7 in GII (P<0.01 vs GI and GIII) and 49.3+/-13.6 in GIII, and arteriolar density was 1.9+/-0.6 arterioles per mm2 in GI, 3.0+/-0.9 in GII (P<0.01 vs GI and GIII) and 1.5+/-0.6 in GIII. Muscle lesions were reduced only within repeated transfection. With single administration, gene expression peaked at 7 days and declined rapidly, but with repeated administration, it remained positive at 50 days. At 90 days of repeated transfection (additional animals), gene expression decreased significantly, but neovessel densities did not. Thus, repeated, but not single, VEGF gene transfection resulted in increased microvasculature, which, in turn, afforded effective protection against ischemic muscle damage.

Low adiponectin levels in primary hypertriglyceridemic male patients.

BACKGROUND AND AIMS: Adiponectin is an adipokine highly and specifically expressed by adipose cells with antiatherogenic and antiinflammatory activities. The aim of the present study was to evaluate plasma adiponectin concentration in patients with primary hypertriglyceridemia and its relationship with metabolic parameters. METHODS AND RESULTS: Male patients with primary hypertriglyceridemia and without the metabolic syndrome (n=22) were compared with normotriglyceridemic individuals (n=25). Plasma adiponectin concentration was measured by standardised enzyme-linked immunosorbent assay. Body mass index, waist circumference, glucose, insulin and non-esterified fatty acid levels, lipoprotein profile, and CETP activity were evaluated. Adiponectin levels were significantly decreased in hypertriglyceridemic patients in comparison with normotriglyceridemic subjects (4292+/-1717 vs. 6939+/-3249 ng/ml, p<0.005, respectively). Adiponectin was negatively associated with glucose (r=-0.44, p<0.01), insulin (r=-0.37, p<0.01), HOMA (r=-0.40, p<0.01), triglycerides (r=-0.36, p<0.01), VLDL-C (r=-0.34, p<0.05), and CETP (r=-0.47, p<0.001). Positive and significant correlations were observed with QUICKI (r=0.49, p<0.001) and HDL-C (r=0.33, p<0.05). In the multiple linear regression analysis, considering waist circumference, QUICKI, Log-triglycerides, HDL-C, and CETP as independent variables, Log-adiponectin showed a positive correlation with QUICKI, with an r(2)=0.229 and p<0.001. Therefore, the independent variable QUICKI explained the 23% of the variance in Log-adiponectin concentration. CONCLUSIONS: We found low adiponectin levels in a population of primary hypertriglyceridemic men without the metabolic syndrome and an independent relationship between adiponectin concentration and insulin resistance. A reduction in insulin sensitivity and its impact on adiponectin concentration could be linked to high non-esterified fatty acid levels, increased triglyceride synthesis in the liver and impaired catabolism of triglyceride-rich lipoproteins.

Análisis de polimorfismos ligados a enfermedad cardiovascular en población general de Buenos Aires / Analysis of the polymorphism linked to cardiovascular disease in a general population from Buenos Aires

Atherosclerotic cardiovascular disease (CVD) is a major health problem around the world. The development of CVD is a complex process, and evidence demonstrates that family history is associated with CVD. The most common forms of CVD are believed to be multifactorial and to result from many genes, each with a small effect working alone or in combination with modifier genes or environmental factors. A large number of candidate gene associatin studies have been conducted for myocardial infarction and atherosclerotic CVD. Variants of the ACE, AGT, AGTR1, APOA5, APOE, CYP11B2, eNOS, FII, FVL, MTHFR, PA11, and genes in general population of Buenos Aires have been examined in the present study; allele frequency, genotype frequency and Hardy Weinberg equilibrium were analyzed in all cases.

Nueva variante en el polimorfismo del intrón 4 de la enzima Oxido Nítrico Sintasa endotelial (eNOS) / A new variant of the polymorphism in the fourth intron from the endothelial nitric oxide synthase enzyme

Nitric oxide (NO) derived from endothelial Nitric Oxide Synthase enzyme (eNOS) is an important mediator of the vascular function. Various polymorphisms have been described for the eNOS gene that has effects on its expression. One of the most studied markers in the eNOS gen is located in the fourth intron and is characterized by the presence of a variable number of tandemly repeated sequence of 27 base pairs. In this work we report the existence and the sequence of a new variant for these polymorphism and we hypothestize its potential role in the regulation of NO productition by eNOS.

Beneficio de la rosuvastatina en el tratamiento de la hipertensión arterial y el remodelamiento ventricular / Beneficial effects of rosuvastatin in patients with arterial hypertension and ventricular remodeling

This paper describes the beneficial effects of rosuvastatin in patients with arterial hypertension in ventricular remodeling. As a conclusion, our data supports new evidence to encourage the use of statins for the treatment of cronic arterial hypertension and venticular remodeling

Effect of preservation solution on graft viability in single-lung transplantation from heart-beating donors in pigs.

BACKGROUND: Low-potassium-dextran preservation solution Perfadex (PER) may provide better outcome of transplanted lungs than high-potassium Euro-Collins (EC) solution. However, there are no comparative studies of the recipient inflammatory response to the graft. PURPOSE: The purpose of this study was to compare EC versus PER as preservation solutions with respect to the functional performance and inflammatory response in single-lung transplantation from heart-beating donors in pigs. MATERIALS AND METHODS: The donor left lung flushed with the corresponding cold preservation solution was stored at 3 degrees C for 3 hours. We assessed hemodynamic values and pulmonary function in the recipient over a 2-hour reperfusion period calculated as percent of basal values, and expressed as mean of the reperfusion period. Interleukin-8 (IL-8) concentration in the donor was estimated in bronchoalveolar lavage fluid 2 hours after recipient reperfusion. Biopsies of the donor right lung and the transplanted lung were obtained to measure myeloperoxidase (MPO) activity. IL-8 and MPO values were expressed as percent of the donor value. We evaluated the wet/dry pulmonary weight ratio (W/D), polymorphonuclear neutrophil count (PMN), and a score of histological damage in the transplanted graft. RESULTS: Pulmonary function evaluated by % static: 66.6 +/- 6.8 (EC), 82.3 +/- 10.2 (PER), and dynamic: 74.0 +/- 7.3 (EC), 89.3 +/- 7.7 (PER) compliances, as well as % IL-8: 562.5 +/- 168.6 (EC), 232.3 +/- 148.7 (PER), % MPO: 485.9 +/- 194.9 (EC), 140.8 +/- 21.1 (PER), W/D: 9.9 +/- 3.1 (EC), 6.8 +/- 1.4 (PER), PMN 13.5 +/- 6.8 (EC), 5.5 +/- 3.3 (PER) and the histological damage score: 3.0 +/- 1.5 (EC), 0.7 +/- 0.4 (PER) showed significant differences between the EC and the PER (P < .01). CONCLUSIONS: PER affords good lung preservation with early graft function and modest evidences of inflammation, lung injury, and edema compared with the EC perfused lung.

Plasmid-mediated VEGF gene transfer induces cardiomyogenesis and reduces myocardial infarct size in sheep.

We have recently reported that in pigs with chronic myocardial ischemia heart transfection with a plasmid encoding the 165 isoform of human vascular endothelial growth factor (pVEGF165) induces an increase in the mitotic index of adult cardiomyocytes and cardiomyocyte hyperplasia. On these bases we hypothesized that VEGF gene transfer could also modify the evolution of experimental myocardial infarct. In adult sheep pVEGF165 (3.8 mg, n=7) or empty plasmid (n=7) was injected intramyocardially 1 h after coronary artery ligation. After 15 days infarct area was 11.3+/-1.3% of the left ventricle in the VEGF group and 18.2+/-2.1% in the empty plasmid group (P<0.02). The mechanisms involved in infarct size reduction (assessed in additional sheep at 7 and 10 days after infarction) included an increase in early angiogenesis and arteriogenesis, a decrease in peri-infarct fibrosis, a decrease in myofibroblast proliferation, enhanced cardiomyoblast proliferation and mitosis of adult cardiomyocytes with occasional cytokinesis. Resting myocardial perfusion (99mTc-sestamibi SPECT) was higher in VEGF-treated group than in empty plasmid group 15 days after myocardial infarction. We conclude that plasmid-mediated VEGF gene transfer reduces myocardial infarct size by a combination of effects including neovascular proliferation, modification of fibrosis and cardiomyocyte regeneration.

Entrance in mitosis of adult cardiomyocytes in ischemic pig hearts after plasmid-mediated rhVEGF165 gene transfer.

Replacement of the cell loss occurring after acute myocardial infarction has been proposed as a potential treatment to prevent heart remodeling and failure. On account that cardiomyocytes express VEGF receptors and that VEGF triggers mitogen-activated protein kinases, we investigated if VEGF gene transfer may induce cardiomyocyte replication. In a pig model of chronic myocardial ischemia achieved by Ameroid occlusion of the left circumflex coronary artery, we observed that direct intramyocardial injection of a plasmid encoding human VEGF(165) induced a several-fold increase in cardiomyocyte mitotic index and in the number of cardiomyocyte nuclei per unit volume as compared with pigs receiving plasmid devoid of gene. Despite images of conventional cytokinesis were not observed, the fact that caryokinesis is an obligatory step for cell division suggests that our finding may contribute to the issue of heart regeneration and may potentially widen the therapeutic spectrum of VEGF gene transfer.

Marked neointimal lipoprotein lipase increase in distinct models of proclivity to atherosclerosis: a feature independent of endothelial layer integrity.

Lipoprotein lipase (LPL) in the arterial wall has been proposed to enhance the retention of apoB-containing lipoproteins, an early event in atherosclerosis. As the neointima is considered the primary site of lipid accumulation in atherogenesis, the arterial expression and location of LPL was investigated in distinct experimental models of neointimal formation in normolipidemic rabbits and rats. Neointima elicited by balloon aortic denudation or raised beneath an anatomically intact endothelial layer by placing a silastic collar around the common carotid artery, both showed a striking LPL immunostaining that mostly co-localized with neointimal smooth muscle cells. Besides, increased LPL protein and mRNA in deendothelialized aortas was demonstrated by Western and Northern blot analysis, respectively, suggesting an enhanced expression of LPL in injured arteries. It was concluded that LPL is increased in neointima developed in either denuded vessels or arteries with a preserved endothelium, a finding which suggests that LPL abundance may be an attribute of the neointima, whatever the stimulus that promotes its formation. On the basis of former evidence concerning the role of LPL in lipid retention, this study provides a possible explanation for the injury-induced vessel susceptibility to atherosclerosis, and the particular proneness of the neointimal layer to lipid accretion.

Potential role of glycerol leading to rat fructose hypertension.

A fructose-enriched diet promotes hypertension in rats. We thought that an enhancement of the glycolytic and/or lipid disorder (s) that raise blood pressure could be the cause. Therefore, we studied 4 groups of Sprague-Dawley rats (+/-200 g): (1) control rats received a standard diet and tap water; (2) the glycerol group of rats received a standard diet and 0.54 mol/L glycerol in tap water; (3) the fructose group was given a fructose-enhanced diet (chow had 55% fructose instead of dextrin) and tap water; and (4) the fructose-glycerol group was given the fructose-enhanced diet and 0. 54 mol/L glycerol in drinking water. At the end of the second week, the findings were as follows. Blood pressure was 149+/-2 mm Hg in the fructose-glycerol group versus 129+/-2 (P<0.001), 131+/-2 (P<0. 001), and 140+/-3 (P<0.005) mm Hg in the control, glycerol, and fructose groups, respectively. Insulinemia was higher in the fructose-glycerol group than the control (P<0.001), glycerol (P<0. 001), and fructose groups (P<0.001); triglyceridemia was higher in the fructose-glycerol (P<0.02), fructose (P<0.05), and glycerol groups (P<0.02) than the control group. Thoracic aorta rings showed a lower ED(50) to 12,13-phorbol dibutyrate in the fructose-glycerol group than in the control (P<0.001), glycerol (P<0.002), and fructose groups (P<0.001). In conclusion, glycerol-fructose administration resulted in hypertriglyceridemia, hyperinsulinemia, and increased vascular sensitivity to 12,13-phorbol dibutyrate (with respect to the control group), and significantly greater expression of protein kinase C alpha and betaII (with respect to the glycerol group).

[Subclinical atherosclerosis. An objective index of susceptibility and vascular risk]. / Aterosclerosis subclínica. Un índice objetivo de susceptibilidad y riesgo vascular.

Clinical data suggest that the individual susceptibility to atherosclerosis is not accounted for only by exposure to classical or "emerging" vascular risk factors. Although recent investigations with transgenic animals have revealed new genetic determinants of susceptibility, little is known concerning this situation in human beings. Even though the human genome project might uncover specific genetic markers in the future, the only early and objective method to identify the susceptible individual at present is to detect atherosclerosis non-invasively. High resolution B-mode ultrasonography of superficial arteries coupled with advanced computer-assisted image processing systems is a highly reproducible method to perform a quali-quantitative early evaluation of already developed wall lesions. Clinically more significant, the detection of silent atherosclerosis has an additional value for risk factor assessment in the prediction of global vascular risk, a relevant index for decision-making in cardiovascular prevention. It is conceivable that the introduction of non-invasive measures of the atherosclerotic burden in risk stratification of asymptomatic subjects will help to target interventions for more rational risk factor control and to reduce the cost/benefit ratio of primary prevention.

Aterosclerosis subclínica. Un índice objetivo de susceptibilidad y riesgo vascular. / [Subclinical atherosclerosis. An objective index of susceptibility and vascular risk]

Clinical data suggest that the individual susceptibility to atherosclerosis is not accounted for only by exposure to classical or [quot ]emerging[quot ] vascular risk factors. Although recent investigations with transgenic animals have revealed new genetic determinants of susceptibility, little is known concerning this situation in human beings. Even though the human genome project might uncover specific genetic markers in the future, the only early and objective method to identify the susceptible individual at present is to detect atherosclerosis non-invasively. High resolution B-mode ultrasonography of superficial arteries coupled with advanced computer-assisted image processing systems is a highly reproducible method to perform a quali-quantitative early evaluation of already developed wall lesions. Clinically more significant, the detection of silent atherosclerosis has an additional value for risk factor assessment in the prediction of global vascular risk, a relevant index for decision-making in cardiovascular prevention. It is conceivable that the introduction of non-invasive measures of the atherosclerotic burden in risk stratification of asymptomatic subjects will help to target interventions for more rational risk factor control and to reduce the cost/benefit ratio of primary prevention.

Determination of bezafibrate, ciprofibrate and fenofibric acid in human plasma by high-performance liquid chromatography.

A selective high-performance liquid chromatographic method to assess either bezafibrate, ciprofibrate or fenofibric acid plasma levels is described. Drugs are extracted with diethyl ether, after acidification with HCL. An isocratic acetonitrile 0.02 M H3PO4 (55:45) mobile phase, a C18 microns) column and UV detection are used. The LOQ found was 0.25 microgram/ml for the three fibrates. Intra- and inter-assay accuracy ranges were 90-107% and 82-111%: 96-115% and 94-107%: 94-114% and 94-126% for bezafibrate, ciprofibrate and fenofibric acid, respectively. Intra- and inter-assay precision (C.V.% ranges) were 1.72-3.06% and 2.66-7.67%: 1.88-4.64% and 0.62-2.99%: 1.26-4.69% and 3.56-7.17% for the three fibrates studied. Its sensitivity, accuracy and precision make it a useful tool for monitoring plasma levels of these drugs in a clinical setting and for research purposes.

Injury produces early rise in lipoprotein lipase activity in rabbit aorta.

The mechanisms following intimal injury predisposing towards atherosclerotic changes have not been fully elucidated. We speculated that a local increase in the enzyme lipoprotein lipase (LPL) might explain a higher susceptibility of the damaged intima to lipid accretion, and so we investigated the effect of balloon endothelial denudation on LPL activity and cholesterol content (LPLa and Cholc, respectively), in aortas from normolipidemic male New Zealand white rabbits. Arteries were obtained from injured and control animals after 2, 6, 8 and 10 weeks to evaluate the shortest period after de-endothelialization necessary to detect LPLa changes. Injury resulted in a 4-fold LPLa rise (P < 0.01), as early as 2 weeks, and the enzymatic activity remained increased throughout the study period. A mild but significant 22% Cholc increase (P < 0.03) was found after 2 weeks of injury, even in this normolipidemic rabbit model. We conclude that physical damage to the intima markedly and soon increases LPLa. This finding might account for the higher lipid accumulation by injured vessels, providing additional support to the hypothesis of LPL as an atherogenic mediator.

[Repeatability of insulin sensitivity estimation using the Minimal Model and comparison with a modified short low-dose insulin tolerance test]. / Reproducibilidad de la cuantificación de la sensibilidad a la acción insulínica con el modelo mínimo y comparación con un test de tolerancia a bajas dosis de insulina.

Hyperinsulinemia and insulin-resistance are metabolic disturbances associated with obesity, essential hypertension, hypertriglyceridemia, glucose intolerance, overt non-insulin dependent diabetes mellitus, polymetabolic syndrome and atherosclerotic disease. The assessment of in vivo insulin sensitivity (SAI in vivo) changes achieved by life style modifications or drug interventions require a reproducible technique. To evaluate the day-to-day intra-individual repeatability of SAI-in vivo, we determined the variation in the SI index (calculated from the Minimal Model of Bergman modified by insulin or MMins) in 11 subjects with a wide range of insulin-resistance. SI (first study) varied from 0.82 to 8.48 x 10(-4) min-1/microU.mL (4.43 +/- 2.85 x 10(-4) min-1/microU.mL mean +/- SD) and highly correlated with SI (second study) (r = 0.89; p = 0.0002). The average interday coefficient of variation was 20.9 +/- 13.9% and was similar in subjects with low or high SI values. We also measured SAI in vivo by assessing the rate of serum glucose decline induced by human cristalline insulin 0.025 U/kg IV dose after a 12-14 hours fasting period (a modified Bonora's method or BBD) in 11 subjects. No subject presented biochemical or symptomatic hypoglycemia. SAI in vivo values determined by BBD varied from 21 a 234 mumol/ml/min (134 +/- 64.8 mumol/ml/min, mean +/- SD). We found a highly significant correlation between SI values obtained from MMins and SAI in vivo assessed by the BBD (r = 0.89, p = 0.0002). Our results suggest that the Mmins is a fairly reproducible procedure and that a BBD is an acceptable option to quantify SAI in vivo, mainly when a fast-execution practice is necessary or cost restrictions are required.