174 research outputs found

    miR-146a is a pivotal regulator of neutrophil extracellular trap formation promoting thrombosis.

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    Neutrophil extracellular traps (NETs) induce a procoagulant response linking inflammation and thrombosis. Low levels of miR-146a, a brake of inflammatory response, are involved in higher risk for cardiovascular events, but the mechanisms explaining how miR-146a exerts its function remain largely undefined. The aim of this study was to explore the impact of miR-146a deficiency in NETosis both, in sterile and non-sterile models in vivo, and to inquire into the underlying mechanism. Two models of inflammation were performed: 1) Ldlr-/- mice transplanted with bone marrow from miR-146a-/- or wild type (WT) were fed high-fat diet, generating an atherosclerosis model; and 2) an acute inflammation model was generated by injecting lipopolysaccharide (LPS) (1 mg/Kg) into miR-146a-/- and WT mice. miR-146a deficiency increased NETosis in both models. Accordingly, miR-146a-/- mice showed significant reduced carotid occlusion time and elevated levels of NETs in thrombi following FeCl3-induced thrombosis. Infusion of DNAse I abolished arterial thrombosis in WT and miR-146a-/- mice. Interestingly, miR-146a deficient mice have aged, hyperreactive and pro-inflammatory neutrophils in circulation that are more prone to form NETs independently of the stimulus. Furthermore, we demonstrated that community acquired pneumonia (CAP) patients with reduced miR-146a levels associated with the T variant of the functional rs2431697, presented an increased risk for cardiovascular events due in part to an increased generation of NETs.This work was supported by research grants from Instituto de Salud Carlos III (ISCIII), Fondo Europeo de Desarrollo Regional “Investing in your future” (PI17/00051 y PI17/01421) (PFIS18/0045: A.M. de los Reyes-García) (CD18/00044: S. Águila), and Fundación Séneca (19873/GERM/15). The CNIC is supported by the ISCIII, the Ministerio de Ciencia, Innovación y Universidades (MCIU), and the Fundación Pro CNIC, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). A.B. Arroyo has a research fellowship from Sociedad Española de Trombosis y Hemostasia (SETH). The MCIU supported A.dM. (predoctoral contract BES-2014-067791).S

    Universal route to optimal few- to single-cycle pulse generation in hollow-core fiber compressors

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    [EN]The chirped pulse amplification (CPA) technique applied to Titanium Sapphire lasers has made intense near-infrared (NIR) ultrashort pulses in the 20−100 fs range widely available for scientific, biomedical and industrial applications. Special efforts have been devoted to generate even shorter pulses, in the few- and single-cycle regime, due to a number of interesting applications. In particular, such pulses have paved the way for attosecond physics and metrology, via the extreme ultraviolet (XUV) attosecond pulse trains and isolated attosecond pulses that can be obtained by high-harmonic generation (HHG). The use of few-cycle optical pulses with durations close to or shorter than 10 fs in the near-infrared, visible and near-ultraviolet spectral regions has been extended in recent years to a wide range of spectroscopic techniques such as impulsive vibrational spectroscopy, time-resolved stimulated Raman spectroscopy, and ultrafast pump-probe absorption spectroscopy. Few-cycle optical pulses have also become an interesting tool for transient absorption microscopy, near-field imaging techniques and for generating ultrashort terahertz radiation. While it is possible to obtain sub-10 fs pulses from CPA or from optical parametric amplification systems, the former is not easy to accomplish, and the latter is not commonplace. Therefore, post-compression techniques are usually employed for the generation of intense few- and even single-cycle pulses in the near- and mid-infrared spectral regions. In order to post-compress ultrafast pulses down to the few-cycle regime, two steps are usually needed. First, nonlinear processes broaden the pulse spectrum, thus decreasing the Fourier-limited pulse duration. In a second step, the spectral phase resulting from the previous stage is compensated, typically using chirped mirrors, gratings, prisms, or other dispersive systems, resulting in a temporally compressed pulse. This scheme was first proposed in the context of optical fibers in the 1980s, and enabled achieving 6 fs pulses when compensating simultaneously the outcoming group delay dispersion (GDD) and third-order dispersion (TOD)

    Influence of the molybdenum cofactor biosynthesis on anaerobic respiration, biofilm formation and motility in Burkholderia thailandensis

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    types: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS.Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Research in Microbiology, 2014, Vol. 165, Issue 1, pp. 41 – 49 DOI: 10.1016/j.resmic.2013.10.009Burkholderia thailandensis is closely related to Burkholderia pseudomallei, a bacterial pathogen and the causative agent of melioidosis. B. pseudomallei can survive and persist within a hypoxic environment for up to one year and has been shown to grow anaerobically in the presence of nitrate. Currently, little is known about the role of anaerobic respiration in pathogenesis of melioidosis. Using B. thailandensis as a model, a library of 1344 transposon mutants was created to identify genes required for anaerobic nitrate respiration. One transposon mutant (CA01) was identified with an insertion in BTH_I1704 (moeA), a gene required for the molybdopterin biosynthetic pathway. This pathway is involved in the synthesis of a molybdopterin cofactor required for a variety of molybdoenzymes, including nitrate reductase. Disruption of molybdopterin biosynthesis prevented growth under anaerobic conditions, when using nitrate as the sole terminal electron acceptor. Defects in anaerobic respiration, nitrate reduction, motility and biofilm formation were observed for CA01. Mutant complementation with pDA-17:BTH_I1704 was able to restore anaerobic growth on nitrate, nitrate reductase activity and biofilm formation, but did not restore motility. This study highlights the potential importance of molybdoenzyme-dependent anaerobic respiration in the survival and virulence of B. thailandensis.BBSRC studentship (C. A. Andreae

    Higher-dose sitagliptin and the risk of congestive heart failure in older adults with CKD

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    Background and objectives Sitagliptin, a dipeptidylpeptidase-4 inhibitor, is commonlyprescribed to patientswith type 2 diabetes. As this drug is primarily eliminated by the kidney, a reduced dose is recommended for patients with CKD. Some evidence suggests that sitagliptin is associated with a higher risk of congestive heart failure, particularly at higher doses.Wecompare the 1-year risk of death or hospitalizationwith congestive heart failure in patients with CKD newly prescribed sitagliptin at \u3c50 versus ≤50 mg/d. Design, setting, participants, & measurements This population-based cohort study included older adults (\u3e66 years) with type 2 diabetes and an eGFR\u3c45 ml/min per 1.73 m2 (but not receiving dialysis) who were newly prescribed sitagliptin between 2010 and 2017 in Ontario, Canada. We used inverse probability of treatment weighting on the basis of propensity scores to balance baseline characteristics. The primary composite outcome was death or hospitalization with congestive heart failure. Secondary outcomes included hospitalization with pancreatitis or hypoglycemia, all-cause hospitalization, and glycemic control. Weighted hazard ratios were obtained using Cox proportional hazards regression, and 95%confidence intervalswere obtained using bootstrap variance estimators. Results Of 9215 patients, 6518 started sitagliptin at \u3e50 mg/d, and 2697 started sitagliptin at ≤50 mg/d. The 1-year risk of death or hospitalization with congestive heart failure did not differ significantly between groups (79 versus 126 events per 1000 person-years; weighted hazard ratio, 0.88; 95% confidence interval, 0.67 to 1.14); hospitalization with pancreatitis (weighted hazard ratio, 0.98; 95% confidence interval, 0.32 to 3.03) and hypoglycemia (weighted hazard ratio, 1.10; 95% confidence interval, 0.64 to 1.90) also did not differ significantly between groups. Patients starting sitagliptin at \u3e50 mg/d had lower mean glycated hemoglobin concentrations (weighted between-group difference, 20.12%; 95% confidence interval, 20.19 to 20.06) and a lower risk of allcause hospitalization (weighted hazard ratio, 0.81; 95% confidence interval, 0.66 to 0.98). Conclusions The risk of death or congestive heart failure was not higher in older adults with CKD starting sitagliptin at \u3e50 versus ≤50 mg/d

    Structural and resting-state MRI detects regional brain differences in young and mid-age healthy APOE-e4 carriers compared with non-APOE-e4 carriers

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    The presence of the e4 allele of the apolipoprotein E (APOE) gene is the best-known genetic risk factor for Alzheimer's disease. In this study, we investigated the link between functional and behavioural differences and regional brain volume and cortical thickness differences in those who carry the e4 allele (e4+) and those who only carry the e3 allele (e3/e3). We studied these genotype populations in two age groups: a young group (average age, 21 years) and a mid-age group (average age, 50 years). High-resolution T1 -weighted MRI scans were analysed with Freesurfer to measure regional white matter brain volume and cortical thickness differences between genotype groups at each age. These data were correlated with behavioural findings in the same cohort. Resting-state MRI was also conducted to identify differences in underlying brain functional connectivity. We found that there was a positive correlation between the thickness of the parahippocampal cortex in young e4+ individuals and performance on an episodic memory task. Young e4+ individuals also showed a positive correlation between white matter volume in the left anterior cingulate and performance on a covert attention task. At mid-age, e4+ individuals had structural differences relative to e3/e3 individuals in these areas: the parahippocampal cortex was thicker and white matter volume in the left anterior cingulate was greater than in e3/e3 individuals. We discuss the possibility that an over-engagement with these regions by e4+ individuals in youth may have a neurogenic effect that is observable later in life. The cuneus appears to be an important region for APOE-driven differences in the brain, with greater functional connectivity among young e3/e3 individuals and greater white matter volume in young e4+ individuals. Copyright © 2016 John Wiley & Sons, Ltd

    Combination antiretroviral therapy and the risk of myocardial infarction

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    Induction of the GABA Cell Phenotype: An In Vitro Model for Studying Neurodevelopmental Disorders

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    Recent studies of the hippocampus have suggested that a network of genes is associated with the regulation of the GAD67 (GAD1) expression and may play a role in γ-amino butyric acid (GABA) dysfunction in schizophrenia (SZ) and bipolar disorder (BD). To obtain a more detailed understanding of how GAD67 regulation may result in GABAergic dysfunction, we have developed an in vitro model in which GABA cells are differentiated from the hippocampal precursor cell line, HiB5. Growth factors, such as PDGF, and BDNF, regulate the GABA phenotype by inducing the expression of GAD67 and stimulating the growth of cellular processes, many with growth cones that form appositions with the cell bodies and processes of other GAD67-positive cells. These changes are associated with increased expression of acetylated tubulin, microtubule-associated protein 2 (MAP2) and the post-synaptic density protein 95 (PSD95). The addition of BDNF, together with PDGF, increases the levels of mRNA and protein for GAD67, as well as the high affinity GABA uptake protein, GAT1. These changes are associated with increased concentrations of GABA in the cytoplasm of “differentiated” HiB5 neurons. In the presence of Ca2+ and K+, newly synthesized GABA is released extracellularly. When the HiB5 cells appear to be fully differentiated, they also express GAD65, parvalbumin and calbindin, and GluR subtypes as well as HDAC1, DAXX, PAX5, Runx2, associated with GAD67 regulation. Overall, these results suggest that the HiB5 cells can differentiate into functionally mature GABA neurons in the presence of gene products that are associated with GAD67 regulation in the adult hippocampus

    The Ischemic Stroke Genetics Study (ISGS) Protocol

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    BACKGROUND: The molecular basis for the genetic risk of ischemic stroke is likely to be multigenic and influenced by environmental factors. Several small case-control studies have suggested associations between ischemic stroke and polymorphisms of genes that code for coagulation cascade proteins and platelet receptors. Our aim is to investigate potential associations between hemostatic gene polymorphisms and ischemic stroke, with particular emphasis on detailed characterization of the phenotype. METHODS/DESIGN: The Ischemic Stroke Genetic Study is a prospective, multicenter genetic association study in adults with recent first-ever ischemic stroke confirmed with computed tomography or magnetic resonance imaging. Patients are evaluated at academic medical centers in the United States and compared with sex- and age-matched controls. Stroke subtypes are determined by central blinded adjudication using standardized, validated mechanistic and syndromic classification systems. The panel of genes to be tested for polymorphisms includes β-fibrinogen and platelet glycoprotein Ia, Iba, and IIb/IIIa. Immortalized cell lines are created to allow for time- and cost-efficient testing of additional candidate genes in the future. DISCUSSION: The study is designed to minimize survival bias and to allow for exploring associations between specific polymorphisms and individual subtypes of ischemic stroke. The data set will also permit the study of genetic determinants of stroke outcome. Having cell lines will permit testing of future candidate risk factor genes

    Final results from the PERUSE study of first-line pertuzumab plus trastuzumab plus a taxane for HER2-positive locally recurrent or metastatic breast cancer, with a multivariable approach to guide prognostication

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    Background: The phase III CLinical Evaluation Of Pertuzumab And TRAstuzumab (CLEOPATRA) trial established the combination of pertuzumab, trastuzumab and docetaxel as standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-positive locally recurrent/metastatic breast cancer (LR/mBC). The multicentre single-arm PERtUzumab global SafEty (PERUSE) study assessed the safety and efficacy of pertuzumab and trastuzumab combined with investigator-selected taxane in this setting. Patients and methods: Eligible patients with inoperable HER2-positive LR/mBC and no prior systemic therapy for LR/mBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab and pertuzumab until disease progression or unacceptable toxicity. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Prespecified subgroup analyses included subgroups according to taxane, hormone receptor (HR) status and prior trastuzumab. Exploratory univariable analyses identified potential prognostic factors; those that remained significant in multivariable analysis were used to analyse PFS and OS in subgroups with all, some or none of these factors. Results: Of 1436 treated patients, 588 (41%) initially received paclitaxel and 918 (64%) had HR-positive disease. The most common grade 653 adverse events were neutropenia (10%, mainly with docetaxel) and diarrhoea (8%). At the final analysis (median follow-up: 5.7 years), median PFS was 20.7 [95% confidence interval (CI) 18.9-23.1] months overall and was similar irrespective of HR status or taxane. Median OS was 65.3 (95% CI 60.9-70.9) months overall. OS was similar regardless of taxane backbone but was more favourable in patients with HR-positive than HR-negative LR/mBC. In exploratory analyses, trastuzumab-pretreated patients with visceral disease had the shortest median PFS (13.1 months) and OS (46.3 months). Conclusions: Mature results from PERUSE show a safety and efficacy profile consistent with results from CLEOPATRA and median OS exceeding 5 years. Results suggest that paclitaxel is a valid alternative to docetaxel as backbone chemotherapy. Exploratory analyses suggest risk factors that could guide future trial design
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