Comparison of skin microvascular reactivity with hemostatic markers of endothelial dysfunction and damage in type 2 diabetes

AIM: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM. METHODS: 54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation. RESULTS: Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls. CONCLUSION: In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state

Association of a sequence variant in DAB2IP with coronary heart disease

Aims: A sequence variant, rs7025486[A], in DAB2IP on chromosome 9q33 has recently been associated with coronary heart disease (CHD). We sought to replicate this finding and to investigate associations with a panel of inflammatory and haemostatic biomarkers. We also sought to examine whether this variant, in combination with a chromosome 9p21 CHD variant (rs10757278) and the Framingham risk score (FRS), could improve the prediction of events compared with the FRS alone. Methods and results: rs7025486 was genotyped in 1386 CHD cases and 3532 controls and was associated with CHD [odds ratio (OR) of 1.16, 95% confidence interval (CI) 1.05-1.29, P = 0.003]. Meta-analysis, using data from the original report and from genome-wide association studies in both the Wellcome Trust Case Control Consortium and the Cardiovascular Health Study, comprising 9968 cases and 20 048 controls, confirmed the association (OR of 1.10, 95% CI 1.06-1.14, P = 3.2 x 10 -6). There was no association with a panel of CHD biomarkers, including any lipid, inflammation, or coagulation trait, nor with telomere length. Addition to the FRS of this variant plus rs10757278 on chromosome 9p21 improved the area under the receiver-operating characteristic curve (AROC) from 0.61 to 0.64 (P = 0.03) as well as improving the reclassification (net reclassification index = 11.1%, P = 0.007). Conclusion: This study replicates a previous association of a variant in DAB2IP with CHD. Addition of multiple variants improves the performance of predictive models based upon classical cardiovascular risk factors

Etude des déterminants génétiques du TAFI [Thrombin-Activatable Fibrinolysis Inhibitor] chez les Africains de Côte d'Ivoire (comparaison avec les Caucasiens)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

L'apport du dosage du facteur VIII dans la thrombophilie

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Paramètres plaquettaires automatisés et pathologie coronaire

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Les statines en thérapeutique cardiovasculaire

Les dyslipidémies athérogènes sont responsables de la plupart des accidents cardiovasculaires ischémiques, qui restent dans les pays industrialisés une des causes majeures de morbidité et de mortalité. Une conduite nutritionnelle adaptée permet parfois de corriger l’excès de lipides circulants, mais lorsqu’elle s’avère insuffisante, la thérapeutique médicamenteuse s’impose. Les inhibiteurs de l’hydroxy-méthylglutaryl-coenzyme A (HMG-CoA) réductase, ou statines, ont il y a plus de dix ans révolutionné le traitement de l’hypercholestérolémie. Cependant, il semble de plus en plus évident que le bénéfice thérapeutique de cette classe de médicaments dépasse celui imputable à la seule baisse du cholestérol circulant puisque les statines, de par leur mode d’action intracellulaire, modulent favorablement l’expression et l’activité de différentes protéines impliquées dans la fonction vasculaire. Grâce à leur extrême diversité d’action sur le compartiment vasculaire, ces molécules sont bien sûr un atout thérapeutique essentiel, mais représentent également un outil pharmacologique pouvant aider le chercheur à évaluer les modifications post-traductionnelles des protéines de signalisation, ainsi que les conséquences de ces modifications sur la régulation de l’expression des gènes

Platelets Potentiate Brain Endothelial Alterations Induced by Plasmodium falciparum

Brain lesions of cerebral malaria (CM) are characterized by a sequestration of Plasmodium falciparum-parasitized red blood cells (PRBC) and platelets within brain microvessels, as well as by blood-brain barrier (BBB) disruption. In the present study, we evaluated the possibility that PRBC and platelets induce functional alterations in brain endothelium. In a human brain endothelial cell line, named HBEC-5i, exhibiting most of the features demanded for a pathophysiological study of BBB, tumor necrosis factor (TNF) or lymphotoxin α (LT-α) reduced transendothelial electrical resistance (TEER), enhanced the permeability to 70-kDa dextran, and increased the release of microparticles, a recently described indicator of disease severity in CM patients. In vitro cocultures showed that platelets or PRBC can have a direct cytotoxic effect on activated, but not on resting, HBEC-5i cells. Platelet binding was required, as platelet supernatant had no effect. Furthermore, platelets potentiated the cytotoxicity of PRBC for TNF- or LT-α-activated HBEC-5i cells when they were added prior to these cells on the endothelial monolayers. This effect was not observed when platelets were added after PRBC. Both permeability and TEER were strongly affected, and the apoptosis rate of HBEC-5i cells was dramatically increased. These findings provide insights into the mechanisms by which platelets can be deleterious to the brain endothelium during CM