413 research outputs found

    IL-18 contributes to susceptibility to Leishmania amazonensis infection by macrophage-independent mechanisms

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    AbstractWe evaluated the role of IL-18 during Leishmania amazonensis infection in C57BL/6 mice, using IL-18KO mice. We showed that IL-18 is involved in susceptibility to L. amazonensis, since IL-18KO mice presented reduced lesions and parasite loads. Because macrophages are the host cells of the parasite, we investigated if macrophages were involved in IL-18-mediated susceptibility to L. amazonensis. We showed that macrophages obtained from WT or IL-18KO responded similarly to L. amazonensis infection. Moreover, we showed that C57BL/6 macrophages do not respond to IL-18, since they do not express IL-18R. Therefore, macrophages are not involved in IL-18-mediated susceptibility to L. amazonensis

    Autoimmune hepatitis in 828 Brazilian children and adolescents: clinical and laboratory findings, histological profile, treatments, and outcomes

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    In this large clinical series of Brazilian children and adolescents, autoimmunehepatitis-1 was more frequent, and patients with autoimmune hepatitis-2 exhibited higherdisease remission rates with earlier response to treatment. Patients with autoimmune hepatitis-1 had a higher risk of death.sentation, laboratory findings, histological profile, treatments, and outcomes of children andadolescents with autoimmune hepatitis.Methods: The medical records of 828 children and adolescents with autoimmune hepatitiswere reviewed. A questionnaire was used to collect anonymous data on clinical presentation,biochemical and histological findings, and treatments.Results: Of all patients, 89.6% had autoimmune hepatitis-1 and 10.4% had autoimmunehepatitis-2. The female sex was predominant in both groups. The median age at symptomonset was 111.5 (6; 210) and 53.5 (8; 165) months in the patients with autoimmune hepatitis1 and autoimmune hepatitis-2, respectively. Acute clinical onset was observed in 56.1% and58.8% and insidious symptoms in 43.9% and 41.2% of the patients with autoimmune hepatitis-1and autoimmune hepatitis-2, respectively. The risk of hepatic failure was 1.6-fold higher forautoimmune hepatitis-2. Fulminant hepatic failure occurred in 3.6% and 10.6% of the patientswith autoimmune hepatitis-1 and autoimmune hepatitis-2, respectively; the risk was 3.1-foldhigher for autoimmune hepatitis-2. The gamma globulin and immunoglobulin G levels were sig-nificantly higher in autoimmune hepatitis-1, while the immunoglobulin A and C3 levels werelower in autoimmune hepatitis-2. Cirrhosis was observed in 22.4% of the patients; biochem-ical remission was achieved in 76.2%. The actuarial survival rate was 93.0%. A total of 4.6%underwent liver transplantation, and 6.9% died (autoimmune hepatitis-1: 7.5%; autoimmunehepatitis-2: 2.4%).Conclusions: In this large clinical series of Brazilian children and adolescents, autoimmunehepatitis-1 was more frequent, and patients with autoimmune hepatitis-2 exhibited higherdisease remission rates with earlier response to treatment. Patients with autoimmune hepatitis-1 had a higher risk of death.info:eu-repo/semantics/publishedVersio

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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