358 research outputs found

    Oversight for clinical uses of autologous adult stem cells: lessons from international regulations

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    Autologous adult stem cells (ASCs) are being administered by physicians for indications that have not been demonstrated as safe and effective in formal clinical trials. Examination of regulatory frameworks across five countries suggests that balancing the demands of research with clinical freedom has created structural weaknesses that are being exploited.funded by the Ministry of Education, Singapore, and the Humanities and Social Sciences (HSS) Division of the Office of the Deputy President (Research and Technology) at the National University of Singapore (NUS)

    Global bionetworks and challenges in regulating autologous adult stem cells

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    Autologous adult stem cells (ASCs) are increasingly being administered to patients with limited evidence from clinical trials that they are safe and effective. The marketing of autologous ASCs predominantly over the Internet by companies based in low-to-middle income countries, such as the Bahamas, Mexico, India and China, is well documented.(1, 2) However, even in countries such as the United States, Japan, and Australia, physicians are prescribing autologous ASCs to patients outside the context of clinical trials. These doctors often form part of loose collaborative networks of clinicians, businesses, patients and researchers operating both domestically and across national boundaries. The emergence of these networks not only puts patients who seek out these interventions at risk: it threatens to undermine the very basis of ‘good medical practice’.funded by the Ministry of Education, Singapore, and the Humanities and Social Sciences (HSS) Division of the Office of the Deputy President (Research and Technology) at the National University of Singapore (NU

    Global bionetworks and challenges in regulating autologous adult stem cells

    Get PDF
    Autologous adult stem cells (ASCs) are increasingly being administered to patients with limited evidence from clinical trials that they are safe and effective. The marketing of autologous ASCs predominantly over the Internet by companies based in low-to-middle income countries, such as the Bahamas, Mexico, India and China, is well documented.(1, 2) However, even in countries such as the United States, Japan, and Australia, physicians are prescribing autologous ASCs to patients outside the context of clinical trials. These doctors often form part of loose collaborative networks of clinicians, businesses, patients and researchers operating both domestically and across national boundaries. The emergence of these networks not only puts patients who seek out these interventions at risk: it threatens to undermine the very basis of ‘good medical practice’.funded by the Ministry of Education, Singapore, and the Humanities and Social Sciences (HSS) Division of the Office of the Deputy President (Research and Technology) at the National University of Singapore (NU

    Oversight for clinical uses of autologous adult stem cells: lessons from international regulations

    Get PDF
    Autologous adult stem cells (ASCs) are being administered by physicians for indications that have not been demonstrated as safe and effective in formal clinical trials. Examination of regulatory frameworks across five countries suggests that balancing the demands of research with clinical freedom has created structural weaknesses that are being exploited.funded by the Ministry of Education, Singapore, and the Humanities and Social Sciences (HSS) Division of the Office of the Deputy President (Research and Technology) at the National University of Singapore (NUS)

    Substantial Increases in Eastern Amazon and Cerrado Biomass Burning‐Sourced Tropospheric Ozone

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    The decline in Amazonian deforestation rates and biomass burning activity (2001–2012) has been shown to reduce air pollutant emissions (e.g., aerosols) and improve regional air quality. However, in the Cerrado region (savannah grasslands in northeastern Brazil), satellite observations reveal increases in fire activity and tropospheric column nitrogen dioxide (an ozone precursor) during the burning season (August‐October, 2005–2016), which have partially offset these air quality benefits. Simulations from a 3‐D global chemistry transport model (CTM) capture this increase in NO2 with a surface increase of ~1 ppbv per decade. As there are limited long‐term observational tropospheric ozone records, we utilize the well‐evaluated CTM to investigate changes in ozone. Here, the CTM suggests that Cerrado region surface ozone is increasing by ~10 ppbv per decade. If left unmitigated, these positive fire‐sourced ozone trends will substantially increase the regional health risks and impacts from expected future enhancements in South American biomass burning activity under climate change

    Impact of the June 2018 Saddleworth Moor wildfires on air quality in northern England

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    The June 2018 Saddleworth Moor fires were some of the largest UK wildfires on record and lasted for approximately three weeks. They emitted large quantities of smoke, trace gases and aerosols which were transported downwind over the highly populated regions of Manchester and Liverpool. Surface observations of PM2.5 indicate that concentrations were 4–5.5 times higher than the recent seasonal average. State-of-the-art satellite measurements of total column carbon monoxide (TCCO) from the TROPOMI instrument on the Sentinel 5—Precursor (S5P) platform, coupled with measurements from a flight of the UK BAe-146–301 research aircraft, are used to quantify the substantial enhancement in emitted trace gases. The aircraft measured plume enhancements with near-fire CO and PM2.5 concentrations >1500 ppbv and >125 μg m−3 (compared to ~100 ppbv and ~5 μg m−3 background concentrations). Downwind fire-plume ozone (O3) values were larger than the near-fire location, indicating O3 production with distance from source. The near-fire O3:CO ratio was (ΔO3/ΔCO) 0.001 ppbv/ppbv, increasing downwind to 0.060–0.105 ppbv/ppbv, suggestive of O3 production enhancement downwind of the fires. Emission rates of CO and CO2 ranged between 1.07 (0.07–4.69) kg s−1 and 13.7 (1.73–50.1) kg s−1, respectively, similar to values expected from a medium sized power station

    A Markov computer simulation model of the economics of neuromuscular blockade in patients with acute respiratory distress syndrome

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    BACKGROUND: Management of acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) is clinically challenging and costly. Neuromuscular blocking agents may facilitate mechanical ventilation and improve oxygenation, but may result in prolonged recovery of neuromuscular function and acute quadriplegic myopathy syndrome (AQMS). The goal of this study was to address a hypothetical question via computer modeling: Would a reduction in intubation time of 6 hours and/or a reduction in the incidence of AQMS from 25% to 21%, provide enough benefit to justify a drug with an additional expenditure of 267(thedifferenceinacquisitioncostbetweenagenericandbrandnameneuromuscularblocker)?METHODS:Thebasecasewasa55yearoldmanintheICUwithARDSwhoreceivesneuromuscularblockadefor3.5days.AMarkovmodelwasdesignedwithhypotheticalpatientsin1of6mutuallyexclusivehealthstates:ICUintubated,ICUextubated,hospitalward,longtermcare,home,ordeath,overaperiodof6months.Thenetmonetarybenefitwascomputed.RESULTS:OurcomputersimulationmodelingpredictedthemeancostforARDSpatientsreceivingstandardcarefor6monthstobe267 (the difference in acquisition cost between a generic and brand name neuromuscular blocker)? METHODS: The base case was a 55 year-old man in the ICU with ARDS who receives neuromuscular blockade for 3.5 days. A Markov model was designed with hypothetical patients in 1 of 6 mutually exclusive health states: ICU-intubated, ICU-extubated, hospital ward, long-term care, home, or death, over a period of 6 months. The net monetary benefit was computed. RESULTS: Our computer simulation modeling predicted the mean cost for ARDS patients receiving standard care for 6 months to be 62,238 (5% – 95% percentiles 42,25942,259 – 83,766), with an overall 6-month mortality of 39%. Assuming a ceiling ratio of 35,000,evenifadrug(thatcost35,000, even if a drug (that cost 267 more) hypothetically reduced AQMS from 25% to 21% and decreased intubation time by 6 hours, the net monetary benefit would only equal $137. CONCLUSION: ARDS patients receiving a neuromuscular blocker have a high mortality, and unpredictable outcome, which results in large variability in costs per case. If a patient dies, there is no benefit to any drug that reduces ventilation time or AQMS incidence. A prospective, randomized pharmacoeconomic study of neuromuscular blockers in the ICU to asses AQMS or intubation times is impractical because of the highly variable clinical course of patients with ARDS

    Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

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    This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion
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