1,118 research outputs found

    Bartonella seropositivity in children with Henoch-Schonlein purpura

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    BACKGROUND: An association between Henoch-Schonlein purpura (HSP) and seropositivity for Bartonella henselae (BH) has been described. The objective of this study was to see if such an association exists in northern Alberta. METHODS: Immunofluorescent antibody testing utilizing an antigen prepared from B. henselae was undertaken on sera from six children with current HSP, 22 children with remote HSP, and 28 controls that were matched for age. Blood from the six children with current HSP was analysed by polymerase chain reaction (PCR) assay with primers derived from the citrate synthase (gltA) gene for the detection of Bartonella DNA. RESULTS: The seropositivity rate for BH was 61% in cases versus 21% in controls (p < 0.03). The PCR assay was negative in all six current cases. CONCLUSION: There is an increased seropositivity rate for BH in children with HSP. However, it is not clear if infection with B. henselae or a related Bartonella species can result in HSP, or if the increased seropositivity is from non-specific or cross-reacting antibodies

    Accuracy of Xpert Ultra in the diagnosis of pulmonary tuberculosis among children in Uganda: a sub-study from the SHINE trial

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    Background: Childhood tuberculosis presents significant diagnostic challenges associated with paucibacillary disease, and requires a more sensitive test. We evaluated the diagnostic accuracy of XpertMTB/Rif Ultra (Ultra) compared to other microbiological tests using respiratory samples from Ugandan children in the SHINE trial.Design/Methods: SHINE is a randomized trial evaluating shorter treatment in 1204 children with minimal TB disease in Africa/India. Among 352 samples and one cervical lymph node fine needle aspirate, one sample was randomly selected per patient and tested with Xpert MTB/Rif (Xpert), Lowenstein Jensen (LJ) and liquid (MGIT) cultures. We selected only uncontaminated stored sample pellet for Ultra testing. We estimated sensitivity of Xpert and Ultra against culture and a composite microbiological reference standard (any positive result).Results: Of 398 children, 353 (89%) had culture, Xpert and Ultra results. Median age was 2.8-years (IQR 1.3-5.3); 8.5% (30/353) HIV-infected, 54.4% (192/353) male. 31/353 (9%) were positive by LJ and/or MGIT; 36 (10%) by Ultra and 16 (5%) by Xpert. Sensitivities were (%; 95% CI), 58% (39-65% (18/31)) for Ultra and 45% (27-64% (14/31)) for Xpert against any culture-positive, with false-positives of <1% and 5.5% for Xpert and Ultra. Against a composite microbiological reference, sensitives were 72% (58-84% (36/50) for Ultra, and 32% (20-47% (16/50)) for Xpert. However, there were 17 samples that are positive only on Ultra (majority trace).Conclusions: Among children screened for minimal TB in Uganda, Ultra has higher sensitivity than Xpert. This represents an important advance for a condition which has posed a diagnostic challenge for decades

    Shorter treatment for minimal tuberculosis (TB) in children (SHINE): A study protocol for a randomised controlled trial

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    BACKGROUND: Tuberculosis (TB) in children is frequently paucibacillary and non-severe forms of pulmonary TB are common. Evidence for tuberculosis treatment in children is largely extrapolated from adult studies. Trials in adults with smear-negative tuberculosis suggest that treatment can be effectively shortened from 6 to 4 months. New paediatric, fixed-dose combination anti-tuberculosis treatments have recently been introduced in many countries, making the implementation of World Health Organisation (WHO)-revised dosing recommendations feasible. The safety and efficacy of these higher drug doses has not been systematically assessed in large studies in children, and the pharmacokinetics across children representing the range of weights and ages should be confirmed. METHODS/DESIGN: SHINE is a multicentre, open-label, parallel-group, non-inferiority, randomised controlled, two-arm trial comparing a 4-month vs the standard 6-month regimen using revised WHO paediatric anti-tuberculosis drug doses. We aim to recruit 1200 African and Indian children aged below 16 years with non-severe TB, with or without HIV infection. The primary efficacy and safety endpoints are TB disease-free survival 72 weeks post randomisation and grade 3 or 4 adverse events. Nested pharmacokinetic studies will evaluate anti-tuberculosis drug concentrations, providing model-based predictions for optimal dosing, and measure antiretroviral exposures in order to describe the drug-drug interactions in a subset of HIV-infected children. Socioeconomic analyses will evaluate the cost-effectiveness of the intervention and social science studies will further explore the acceptability and palatability of these new paediatric drug formulations. DISCUSSION: Although recent trials of TB treatment-shortening in adults with sputum-positivity have not been successful, the question has never been addressed in children, who have mainly paucibacillary, non-severe smear-negative disease. SHINE should inform whether treatment-shortening of drug-susceptible TB in children, regardless of HIV status, is efficacious and safe. The trial will also fill existing gaps in knowledge on dosing and acceptability of new anti-tuberculosis formulations and commonly used HIV drugs in settings with a high burden of TB. A positive result from this trial could simplify and shorten treatment, improve adherence and be cost-saving for many children with TB. Recruitment to the SHINE trial begun in July 2016; results are expected in 2020

    Update: cohort mortality study of workers highly exposed to polychlorinated biphenyls (PCBs) during the manufacture of electrical capacitors, 1940-1998

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    BACKGROUND: The National Institute for Occupational Safety and Health previously reported mortality for a cohort of workers considered highly exposed to polychlorinated biphenyls (PCBs) between 1939 and 1977 at two electrical capacitor manufacturing plants. The current study updated vital status, examined liver and rectal cancer mortality previously reported in excess in this cohort and evaluated mortality from non-Hodgkin's lymphoma (NHL) and cancers of the stomach, intestine, breast, prostate, skin (melanoma) and brain reported to be in excess in other cohort and case-control studies of PCB-exposed persons. METHODS: Mortality was updated through 1998 for 2572 workers. Age-, gender-, race- and calendar year-adjusted standardized mortality ratios (SMRs) and 95% confidence intervals (CI) were calculated using U.S., state and county referent rates. SMRs using U.S. referent rates are reported. Duration of employment was used as a surrogate for exposure. RESULTS: Consistent with the previous follow-up, mortality from biliary passage, liver and gall bladder cancer was significantly elevated (11 deaths, SMR 2.11, CI 1.05 – 3.77), but mortality from rectal cancer was not (6 deaths, SMR 1.47, CI 0.54 – 3.21). Among women, mortality from intestinal cancer (24 deaths, SMR 1.89, CI 1.21 – 2.82) and from "other diseases of the nervous system and sense organs", which include Parkinson's disease and amyotrophic lateral sclerosis, (15 deaths, SMR 2.07, CI 1.16 – 3.42) were elevated. There were four ALS deaths, all women (SMR 4.35, CI 1.19–11.14). Mortality was elevated for myeloma (7 deaths, SMR 2.11, CI 0.84 – 4.34), particularly among workers employed 10 years or more (5 deaths, SMR 2.80, CI 0.91 – 6.54). No linear associations between mortality and duration of employment were observed for the cancers of interest. CONCLUSION: This update found that the earlier reported excess in this cohort for biliary, liver and gall bladder cancer persisted with longer follow-up. Excess mortality for intestinal cancer among women was elevated across categories of duration of employment; myeloma mortality was highest among those working 10 years or more. The small numbers of deaths from liver and intestinal cancers, myeloma and nervous system diseases coupled with the lack of an exposure-response relationship with duration of employment preclude drawing definitive conclusions regarding PCB exposure and these causes of death

    Prognostic and predictive value of clinical and biochemical factors in breast cancer patients with bone metastases receiving "metronomic" zoledronic acid

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    <p>Abstract</p> <p>Background</p> <p>To assess prognostic and predictive effects of clinical and biochemical factors in our published randomized study of a weekly low dose (metronomic arm) versus a conventional dosage of zoledronic acid (conventional arm) in breast cancer patients with bone metastases.</p> <p>Methods</p> <p>Treatment outcome of 60 patients with bone metastases were used to assess impacts of following potential prognostic factors, estrogen receptor status, lymph node status, 2 year-disease free interval (DFI), numbers of chemotherapy regimens administered, interventions, and serum levels of VEGF, N-telopeptide of type I collagen (NTx), CEA, and CA 15-3.</p> <p>Results</p> <p>In univariate analyses, patients pretreated with 2 or fewer chemotherapy regimens, ER-positive tumors, 3 or fewer lymph nodes, DFI of more than 2 years, serum VEGF of less than 500 pg/mL after 3 months of intervention, serum CEA and CA 15-3 of less than ULN, and baseline serum NTx of less than 18 nM BCE had significantly longer progression free survival (PFS). The multivariate analysis showed that ER positivity (hazard ratio [HR], 0.295; 95% confidence interval [CI], 0.141-0.618; P = 0.001), serum VEGF of less than 500 pg/mL after 3 months of intervention (HR, 2.220; 95% CI, 1.136-4.338; P = 0.020), baseline serum NTx of less than 18 nM BCE (HR, 2.842; 95% CI, 1.458-5.539; P = 0.001), and 2 or fewer chemotherapy regimens received (HR, 7.803; 95% CI, 2.884-21.112; P = 0.000) were associated with a better PFS. When evaluating the predictive effect of the biochemical factors, an interaction between NTx and zoledronic acid intervention was shown (P = 0.005). The HR of weekly low dose versus a conventional dosage of zoledronic acid was estimated to be 2.309 (99% CI, 1.067-5.012) in patients with baseline serum NTx of more than 18 nM BCE, indicating a superiority of weekly low dose of zoledronic acid.</p> <p>Conclusions</p> <p>ER, serum VEGF level after intervention, and numbers of chemotherapy regimens administered are prognostic but not predictive factors in breast cancer patients with bone metastases. Patients with baseline serum NTx of more than 18 nM BCE might benefit more from weekly low-dose of zoledronic acid.</p> <p>Trial registration</p> <p>ClinicalTrials.gov unique identifier: ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00524849">NCT00524849</a></p

    Use of an innovative model to evaluate mobility in seniors with lower-limb amputations of vascular origin: a pilot study

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    <p>Abstract</p> <p>Background</p> <p>The mobility of older individuals has often been only partially assessed, without considering all important aspects such as potential (available) versus effective (used) mobilities and the physical and psychosocial factors that modulate them. This study proposes a new model for evaluating mobility that considers all important aspects, applied here to lower-limb amputees with vascular origin. This model integrates the concepts of potential mobility (e.g. balance, speed of movement), effective mobility (e.g. life habits, movements in living areas) and factors that modulate these two types of mobility (e.g. strength, sensitivity, social support, depression). The main objective was to characterize potential and effective mobility as well as mobility modulators in a small sample of people with lower-limb amputations of vascular origin with different characteristics. The second objective of this pilot study was to assess the feasibility of measuring all variables in the model in a residential context.</p> <p>Methods</p> <p>An observational and transversal design was used with a heterogeneous sample of 10 participants with a lower-limb amputation of vascular origin, aged 51 to 83, assessed between eight and 18 months after discharge from an acute care hospital. A questionnaire of participant characteristics and 16 reliable and valid measurements were used.</p> <p>Results</p> <p>The results show that the potential mobility indicators do not accurately predict effective mobility, i.e., participants who perform well on traditional measures done in the laboratory or clinic are not always those who perform well in the real world. The model generated 4 different profiles (categories) of participants ranging from reduced to excellent potential mobility and low to excellent effective mobility, and characterized the modulating factors. The evaluations were acceptable in terms of the time taken (three hours) and the overall measurements, with a few exceptions, which were modified to optimize the data collected and the classification of the participants. For the population assessed, the results showed that some of the negative modulators (particularly living alone, no rehabilitation, pain, limited social support, poor muscle strength) played an important role in reducing effective mobility.</p> <p>Conclusion</p> <p>The first use of the model revealed interesting data that add to our understanding of important aspects linked to potential and effective mobility as well as modulators. The feasibility of measuring all variables in the model in a residential context was demonstrated. A study with a large number of participants is now warranted to rigorously characterize mobility levels of lower-limb amputees with vascular origin.</p

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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