6,685 research outputs found
Usefulness of (13)C-urea breath test in the diagnosis of gastric helicobacter pylori infection
Helicobacter pylori chronically infects half of the human population and is associated with gastritis, peptic ulcer and gastric cancer. C-13-urea breath test (UBT) is the main in vivo tool for the diagnosis of H. pylori infection. In this study, the safety and the accuracy of UBT were evaluated.A group of 492 dyspeptic patients was studied by UBT, the results were expressed as the difference over baseline at 30 min (DOB30). All patients were evaluated for systemic, gastrointestinal or allergic-type adverse reactions after ingestion of 75 mg C-13-urea and citric acid in aqueous solution, The first 256 patients enrolled also underwent endoscopy and gastric biopsy. Patients positive on histology were considered infected.UBT was well tolerated and none of the 492 patients had any systemic or allergic-type adverse reaction. Among the 256 patients studied with histology, 116 were H. pylori positive on biopsies. Using 4 %o as cut-off value for DOB30, 115 out of the 256 patients were positive on UBT, with only 2 false positive and 3 false negative, With this threshold, the sensitivity, specificity, and accuracy of the UBT were 97.4 %, 98.5 %, and 98.0 %, respectively.C-13-UBT has proven to be a safe and simple, yet accurate, test for the non-invasive diagnosis and monitoring of H. pylori infection
First observation and measurement of the resonant structure of the lambda_b->lambda_c pi-pi+pi- decay mode
We present the first observation of the lambda_b->lambda_c pi-pi+pi- decay
using data from an integrated luminosity of approximately 2.4 fb-1 of ppbar
collisions at ECM=1.96 TeV, collected with the CDF II detector at the Fermilab
Tevatron. We also present the first observation of the resonant decays
lambda_b->sigma_c(2455)0 pi+pi- ->lambda_c pi-pi+pi-, lambda_b->sigma_c(2455)++
pi-pi- ->lambda_c pi-pi+pi-, lambda_b->lambda_c(2595)+ pi- ->lambda_c pi-pi+pi-
and lambda_b->lambda_c(2625)+ pi- ->lambda_c pi-pi+pi-, and measure their
relative branching ratios.Comment: 3 pages, 3 figures, to appear in the proceedings of LEPTON PHOTON
2009, Hamburg, German
serological markers of pulmonary tuberculosis and of response to anti tuberculosis treatment in a patient population in guinea
The aim of the study was to evaluate serological correlates of active tuberculosis and of response to antituberculosis treatment in a cohort of HIV-negative patients with pulmonary tuberculosis studied at diagnosis and during treatment at the Service de Pneumo-Phtisiologie, Centre Hospitalier-Universitaire Ignace Deen, Conakry, Republic of Guinea. Two similar cohorts of HIV-negative healthy households of patients and healthy community controls were included in the study. Plasma samples were obtained from 168 untreated tuberculosis patients, 167 healthy household controls, and 168 healthy community controls. Serial plasma samples were also obtained from the tuberculosis patients at 2 and 8 months after initiation of chemotherapy. IgG antibody levels were measured by an enzyme-linked immunosorbent assay (ELISA) using ten purified M. tuberculosis antigens. ELISA results were analysed by comparing geometric means of data. Of the ten antigens tested, five (14kDa Ag, 19kDa Ag, AlaDH, MS, and MPT83) elicited similar antibody responses in untreated TB patients and controls. In contrast, levels of three antibodies (ESAT-6, LAM, and 38kDa Ag) were higher in untreated TB patients than in household or community controls (p<0.0001). Levels were higher in untreated patients than in community controls also for the anti-Rv2626c antibody (p = 0.0001) and, at a lower significance level, for the anti-FdxA antibody (p<0.025). Antibody levels against ESAT-6 and Rv2626c decreased during therapy, while antibody levels to the 38 kDa antigen and LAM increased during therapy; FdxA antibody levels did not vary with treatment. Neither severity of presentation nor chest X-ray patterns affected levels of these antibodies before treatment. In contrast, after the 8-month therapeutic course, patients who presented with moderate/severe disease had higher levels of anti-ESAT-6, anti-FdxA, and anti-38kDa antibodies than those of patients with mild disease onset. Patients with bilateral lung lesions had significantly higher anti-38kDa and anti-LAM levels, both at diagnosis and after 8-month treatment, than patients with lesions involving only one lung. Antibodies to alanine dehydrogenase and malate synthetase measured at initiation of treatment were higher in tuberculosis patients who subsequently failed therapy than in those who were cured. The main conclusions of the study are: a) plasma levels of antibodies to a number of M. tuberculosis represent serological correlates of active disease; b) these correlates are affected in an antigen-specific fashion by anti-tuberculosis treatment; c) particular serological markers may be predictive of treatment outcome
Human 60 kDa heat shock protein is a target autoantigen of T cells derived from atherosclerotic plaques.
Dark matter searches at LHC
Besides Standard Model measurements and other Beyond Standard Model studies,
the ATLAS and CMS experiments at the LHC will search for Supersymmetry, one of
the most attractive explanation for dark matter. The SUSY discovery potential
with early data is presented here together with some first results obtained
with 2010 collision data at 7 TeV. Emphasis is placed on measurements and
parameter determination that can be performed to disentangle the possible SUSY
models and SUSY look-alike and the interpretation of a possible positive
supersymmetric signal as an explanation of dark matter.Comment: 15 pages, 14 figures, Invited plenary talk given at DISCRETE 2010:
Symposium On Prospects In The Physics Of Discrete Symmetries, 6-11 Dec 2010,
Rome, Ital
H(+),K(+)-atpase (proton pump) is the target autoantigen of Th1-type cytotoxic T cells in autoimmune gastritis.
Decline in total serum IgE and soluble CD30 in the context of soil-transmitted helminth decline in Bolivia
In the Bolivian Chaco, recent surveys documented a dramatic decrease in the prevalence of soil-transmitted helminth (STH) infections as compared with the 1980s after thirty years of preventive chemotherapy (PC). Concomitant immunological rearrangements are expected. Because nematode infections are associated with increased levels of circulating IgE and glycoprotein CD30 soluble form (sCD30), this study aims to evaluate changes in serological markers of T helper (Th)2-cells activity between 1987 (high STH prevalence) and 2013 (low STH prevalence) in rural communities in the Bolivian Chaco area. We collected 151 sera during two different surveys in 1987 (n = 65) and 2013 (n = 86) and measured the concentration of total IgE and sCD30 by immunoassays. We found a statistically significant age-independent decrease in the total IgE (P < 0.0001) and sCD30 (P < 0.0001) from 1987 to 2013. The significant decrease in serological Th2 markers (IgE and sCD30) between 1987 and 2013 is consistent with the drop in STH prevalence in this geographical area during the same period of time. Further studies might elucidate the clinical and epidemiological impact of these serological rearrangements
Intrinsic factor recognition promotes T helper 17/T helper 1 autoimmune gastric inflammation in patients with pernicious anemia.
Precision measurements of the top quark mass from the Tevatron in the pre-LHC era
The top quark is the heaviest of the six quarks of the Standard Model.
Precise knowledge of its mass is important for imposing constraints on a number
of physics processes, including interactions of the as yet unobserved Higgs
boson. The Higgs boson is the only missing particle of the Standard Model,
central to the electroweak symmetry breaking mechanism and generation of
particle masses. In this Review, experimental measurements of the top quark
mass accomplished at the Tevatron, a proton-antiproton collider located at the
Fermi National Accelerator Laboratory, are described. Topologies of top quark
events and methods used to separate signal events from background sources are
discussed. Data analysis techniques used to extract information about the top
mass value are reviewed. The combination of several most precise measurements
performed with the two Tevatron particle detectors, CDF and \D0, yields a value
of \Mt = 173.2 \pm 0.9 GeV/.Comment: This version contains the most up-to-date top quark mass averag
Evidence for the exclusive decay Bc+- to J/psi pi+- and measurement of the mass of the Bc meson
We report first evidence for a fully reconstructed decay mode of the
B_c^{\pm} meson in the channel B_c^{\pm} \to J/psi \pi^{\pm}, with J/psi \to
mu^+mu^-. The analysis is based on an integrated luminosity of 360 pb$^{-1} in
p\bar{p} collisions at 1.96 TeV center of mass energy collected by the Collider
Detector at Fermilab. We observe 14.6 \pm 4.6 signal events with a background
of 7.1 \pm 0.9 events, and a fit to the J/psi pi^{\pm} mass spectrum yields a
B_c^{\pm} mass of 6285.7 \pm 5.3(stat) \pm 1.2(syst) MeV/c^2. The probability
of a peak of this magnitude occurring by random fluctuation in the search
region is estimated as 0.012%.Comment: 7 pages, 3 figures. Version 3, accepted by PR
- …