Molecular diagnosis of Granulicatella elegans on the cardiac valve of a patient with culture-negative endocarditis

We herein report one case of culture-negative infectious endocarditis (IE) where the organism, Granulicatella elegans, was identified by molecular analysis using broad-range PCR primers complementary to the 16S rRNA gene on the removed valve. The results and utility of this method are discussed.     

Echocardiography predicts embolic events in infective endocarditis

OBJECTIVES: The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism. BACKGROUND: The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship. METHODS: Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients. RESULTS: Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length >10 mm (60%, p < 0.001) and in patients with mobile vegetations (62%, p < 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (> 15 mm) (83%, p < 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p = 0.03) and mobility (p = 0.01). CONCLUSIONS: Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations > 15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy.     

Streptococcus pneumoniae endocarditis: persistence of DNA on heart valve material 7 years after infectious episode

We amplified by PCR and sequenced Streptococcus pneumoniae rpoB from DNA of the cardiac valve of a man who had presented with pneumococcal endocarditis 7 years earlier. Histopathologically, the valve did not show evidence of endocarditis. This case raises the question of persistence of DNA without any evidence of infection.     

Targeting the histone demethylase LSD1 prevents cardiomyopathy in a mouse model of laminopathy

LMNA mutations in patients are responsible for a dilated cardiomyopathy. Molecular mechanisms underlying the origin and development of the pathology are unknown. Herein, using mouse pluripotent embryonic stem cells (ESCs) and a mouse model both harboring the p.H222P Lmna mutation, we found early defects in cardiac differentiation of mutated ESCs and dilatation of mutated embryonic hearts at E13.5, pointing to a developmental origin of the disease. Using mouse ESCs, we demonstrated that cardiac differentiation of Lmna^H222P/+ was impaired at the mesodermal stage. Expression of Mesp1, a mesodermal cardiogenic gene involved in epithelial-to-mesenchymal transition of epiblast cells, as well as Snai1 and Twist expression, was decreased in Lmna^H222P/+ cells compared with WT cells in the course of differentiation. In turn, cardiomyocyte differentiation was impaired. ChIP assay of H3K4me1 in differentiating cells revealed a specific decrease of this histone mark on regulatory regions of Mesp1 and Twist in Lmna^H222P/+ cells. Downregulation or inhibition of LSD1 that specifically demethylated H3K4me1 rescued the epigenetic landscape of mesodermal Lmna^H222P/+ cells and in turn contraction of cardiomyocytes. Inhibition of LSD1 in pregnant mice or neonatal mice prevented cardiomyopathy in E13.5 Lmna^H222P/H222P offspring and adults, respectively. Thus, LSD1 appeared to be a therapeutic target to prevent or cure dilated cardiomyopathy associated with a laminopathy.     

Décrochage du sens moral au sein des forces armées en milieu opérationnel : une approche constructive

Despite the international ratification of Geneva Conventions, which define rules to protect people in situations of war, violence beyond the law of armed conflict is not uncommon. Fairly regularly, the subject makes the headlines. A notable example is the recent publication of confidential informations by Wikileaks. What is at stake is the coherence of UN mandates to western armies. This coherence contributes to the preservation of mental balance of military forces.     

Ventricular allorhythmia during infarct-related ventricular tachycardia

Ventricular allorhythmia is an electrocardiogram feature leading to a pattern of "regularly irregular" arrhythmia mainly reported during non-life-threatening organized atrial tachycardia. We report the infrequent case of a patient presenting with ventricular allorhythmia during infarct-related ventricular tachycardia. The potential mechanisms of this tachycardia are discussed.