BackgroundLimited data are available on the characteristics, clinical management, and outcomes of patients with atrial fibrillation at risk of stroke, from a worldwide perspective. The aim of this study was to describe the baseline characteristics and initial therapeutic management of patients with non-valvular atrial fibrillation across the spectrum of sites at which these patients are treated.Methods and FindingsThe Global Anticoagulant Registry in the FIELD (GARFIELD) is an observational study of patients newly diagnosed with non-valvular atrial fibrillation. Enrollment into Cohort 1 (of 5) took place between December 2009 and October 2011 at 540 sites in 19 countries in Europe, Asia-Pacific, Central/South America, and Canada. Investigator sites are representative of the distribution of atrial fibrillation care settings in each country. Cohort 1 comprised 10,614 adults (≥18 years) diagnosed with non-valvular atrial fibrillation within the previous 6 weeks, with ≥1 investigator-defined stroke risk factor (not limited to those in existing risk-stratification schemes), and regardless of therapy. Data collected at baseline included demographics, medical history, care setting, nature of atrial fibrillation, and treatments initiated at diagnosis. The mean (SD) age of the population was 70.2 (11.2) years; 43.2% were women. Mean±SD CHADS2 score was 1.9±1.2, and 57.2% had a score ≥2. Mean CHA2DS2-VASc score was 3.2±1.6, and 8,957 (84.4%) had a score ≥2. Overall, 38.0% of patients with a CHADS2 score ≥2 did not receive anticoagulant therapy, whereas 42.5% of those at low risk (score 0) received anticoagulant therapy.ConclusionsThese contemporary observational worldwide data on non-valvular atrial fibrillation, collected at the end of the vitamin K antagonist-only era, indicate that these drugs are frequently not being used according to stroke risk scores and guidelines, with overuse in patients at low risk and underuse in those at high risk of stroke.Trial RegistrationClinicalTrials.gov TRI08888

Background-Peripheral homing of progenitor cells in areas of diseased organs is critical for tissue regeneration. The chemokine stromal cell-derived factor-1 (SDF-1) regulates homing of CD34 ϩ stem cells. We evaluated the role of platelet-derived SDF-1 in adhesion and differentiation of human CD34 ϩ cells into endothelial progenitor cells. Methods and Results-Adherent platelets express substantial amounts of SDF-1 and recruit CD34 ϩ cells in vitro and in vivo. A monoclonal antibody to SDF-1 or to its counterreceptor, CXCR4, inhibits stem cell adhesion on adherent platelets under high arterial shear in vitro and after carotid ligation in mice, as determined by intravital fluorescence microscopy. Platelets that adhere to human arterial endothelial cells enhance the adhesion of CD34 ϩ cells on endothelium under flow conditions, a process that is inhibited by anti-SDF-1. During intestinal ischemia/reperfusion in mice, anti-SDF-1 and anti-CXCR4, but not isotype control antibodies, abolish the recruitment of CD34 ϩ cells in microcirculation. Moreover, platelet-derived SDF-1 binding to CXCR4 receptor promotes platelet-induced differentiation of CD34 ϩ cells into endothelial progenitor cells, as verified by colony-forming assays in vitro. Conclusions-These

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The tau protein is central to the etiology of several neurodegenerative diseases, including Alzheimer's disease, a subset of frontotemporal dementias, progressive supranuclear palsy and dementia following traumatic brain injury, yet the proteins it interacts with have not been studied using a systematic discovery approach. Here we employed mild in vivo crosslinking, isobaric labeling, and tandem mass spectrometry to characterize molecular interactions of human tau in a neuroblastoma cell model. The study revealed a robust association of tau with the ribonucleoproteome, including major protein complexes involved in RNA processing and translation, and documented binding of tau to several heat shock proteins, the proteasome and microtubule-associated proteins. Follow-up experiments determined the relative contribution of cellular RNA to the tau interactome and mapped interactions to N-or C-terminal tau domains. We further document that expression of P301L mutant tau disrupts interactions of the C-terminal half of tau with heat shock proteins and the proteasome. The data are consistent with a model whereby a higher propensity of P301L mutant tau to aggregate may reflect a perturbation of its chaperone-assisted stabilization and proteasome-dependent degradation. Finally, using a global proteomics approach, we show that heterologous expression of a tau construct that lacks the C-terminal domain, including the microtubule binding domain, does not cause a discernible shift of the proteome except for a significant