La thrombopénie induite par héparine : mise au point

International audienc

Dabigatran versus vitamin k antagonist: an observational across-cohort comparison in acute coronary syndrome patients with atrial fibrillation

International audienc

A 2,000-year-old specimen with intraerythrocytic Bartonella quintana

Photogrammetry and cascading microscopy investigations of dental pulp specimens collected from 2,000-year-old individuals buried in a Roman necropolis in Besancon, France, revealed unprecedented preserved tissular and cellular morphology. Photogrammetry yielded 3-D images of the smallest archaeological human remains ever recovered. Optical microscopy examinations after standard haematoxylin-phloxine-saffron staining and anti-glycophorin A immunohistochemistry exposed dental pulp cells, in addition erythrocytes were visualised by electron microscopy, which indicated the ancient dental pulp trapped a blood drop. Fluorescence in situ hybridisation applied on red blood cells revealed the louse-borne pathogen Bartonella quintana, a finding confirmed by polymerase chain reaction assays. Through paleohistology and paleocytology, we demonstrate that the ancient dental pulp preserved intact blood cells at the time of the individual's death, offering an unprecedented opportunity to engage in direct and indirect tests to diagnose pathogens in ancient buried individuals

Levels of circulating endothelial progenitor cells are related to uremic toxins and vascular injury in hemodialysis patients

International audienceBackground: Patients suffering from chronic kidney diseases (CKD) exhibit cardiovascular diseases and profound endothelial dysfunction. CKD patients have reduced numbers of endothelial progenitor cells, but little is known about the factors influencing these numbers. Objectives: Among these factors, we hypothesized that uremic toxins and vascular injury affect endothelial progenitor cells. Patients/methods: Thirty-eight hemodialysis patients were investigated and compared with 21 healthy controls. CD34+CD133+ immature progenitors, CD34+KDR+ endothelial progenitors cells (EPC) and myeloid EPC (mEPC) were counted in peripheral blood. Levels of uremic toxins beta(2)-microglobulin, indole-3 acetic acid, indoxylsulfate, p-cresylsulfate and homocysteine were measured. Vascular injury was assessed in hemodialysis (HD) patients by measuring aortic pulse wave velocity and plasma levels of endothelial microparticles. In vitro experiments were performed to study the effect of uremic toxins on apoptosis of progenitor cells. Results and conclusions: CD34+CD133+ immature progenitor cell number was negatively correlated with the levels of uremic toxins beta(2)-microglobulin and indole-3 acetic acid. In vitro, indole-3 acetic acid induced apoptosis of CD133+ cells. These data indicate uremic toxins have a deleterious role on progenitor cells, early in the differentiation process. Moreover, mEPC number was positively correlated with markers of vascular injury-pulse wave velocity and endothelial microparticle levels. This suggests that vascular lesions could stimulate progenitor cell mobilization, even in a context of reduced EPC induced by CKD. In conclusion, uremic toxins and vascular injury appear to affect endothelial progenitor cell biology in CKD

Emergence of the concept of platelet reactivity monitoring of response to thienopyridines

Clinical trials have demonstrated the beneficial impact of clopidogrel in preventing major adverse cardiovascular events (MACE), particularly in patients undergoing percutaneous coronary intervention (PCI). The concept of biological clopidogrel resistance emerged with the finding of persistent platelet activation despite clopidogrel therapy in some patients. Further, a link between biological clopidogrel resistance and thrombotic recurrence after PCI was observed and a threshold of platelet reactivity (PR) for thrombotic events was suggested. Consistently, in recent trials, enhanced PR inhibition translated into a reduction in the rate of MACE after PCI. This review aims to present the emergence of the concept of PR monitoring in patients undergoing PCI following recent advances in this field.6 page(s

Spondylodiscitis complicating infective endocarditis

Objective The primary objective was to assess the characteristics and prognosis of pyogenic spondylodiscitis (PS) in patients with infective endocarditis (IE). The secondary objectives were to assess the factors associated with occurrence of PS. Methods Prospective case-control bi-centre study of 1755 patients with definite IE with (n=150) or without (n=1605) PS. Clinical, microbiological and prognostic variables were recorded. Results Patients with PS were older (mean age 69.7±18 vs 66.2±14; p=0.004) and had more arterial hypertension (48% vs 34.5%; p<0.001) and autoimmune disease (5% vs 2%; p=0.03) than patients without PS. The lumbar vertebrae were the most frequently involved (84 patients, 66%), especially L4-L5. Neurological symptoms were observed in 59% of patients. Enterococci and Streptococcus gallolyticus were more frequent (24% vs 12% and 24% vs 11%; p<0001, respectively) in the PS group. The diagnosis of PS was based on contrast-enhanced MRI in 92 patients, bone CT in 88 patients and 18 F-FDG PET/CT in 56 patients. In-hospital (16% vs 13.5%, p=0.38) and 1-year (21% vs 22%, p=0.82) mortalities did not differ between patients with or without PS. Conclusions PS is a frequent complication of IE (8.5% of IE), is observed in older hypertensive patients with enterococcal or S. gallolyticus IE, and has a similar prognosis than other forms of IE. Since PS is associated with specific management, multimodality imaging including MRI, CT and PET/CT should be used for early diagnosis of this complication of endocarditis