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197篇 您的检索式:作者名="David MITCHELL"
    题名 作者 年代 出处 被引量
1The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hirnantian Stage (the uppermost of the Ordovician System)显示文摘Xu Chen Jiayu Rong Junxuan Fan Renbin Zhan Charles E. Mitchell David A. T. Harper Michael J. Melchin Ping'an Peng Stan C. Finney Xiaofeng Wang 2006Episodes2006,29,3:61
2将卒中纳入心血管风险预测工具美国心脏协会/美国卒中协会对医疗卫生专业人员的声明显示文摘背景和目的目前美国针对心血管事件风险预测以及一级和二级预防的指南声明均使用绝对风险估计值来识别血管事件高危患者以及可从特定干预措施中获益的患者。然而,这些指南并未明确地包括卒中患者。本指南对现有证据和争论进行概述以支持:(1)将卒中(尤其是动脉粥样硬化性卒中)患者纳入心血管病绝对风险增高的患者群体;(2)将卒中纳入血管性疾病风险预测工具的转归预测因素。方法和结果写作组成员由委员会联合主席基于先前在相关领域的研究成果来提名,并得到美国心脏协会(American Heart Association,AHA)卒中委员会科学声明监督委员会以及文稿监督委员会的批准。作者采用系统文献回顾(覆盖1980年1月至2010年3月期间的文献)并参考以往公布的指南、个人资料以及专家观点,以归纳现有证据,提出当前知识的不足,并根据AHA标准对适当的问题制定推荐意见。所有写作组成员均有机会对推荐意见进行评论并批准了最终版本。经广泛的AHA内部同行评议以及卒中委员会领导阶层和科学声明监督委员会的审阅后,最终获得AHA科学咨询和协调委员会的批准。将卒中患者(尤其是动脉粥样硬化性卒中患者)纳入冠状动脉和心血管病绝对高危人群的原因如下。首先,有证据显示,缺血性卒中患者发生致死性和非致死性心肌梗死或猝死的绝对风险增高,10年绝对风险≥20%,这一风险阈值已被一些指南用于定义冠状动脉疾病风险等危症。其次,纳入动脉粥样硬化性卒中的原因与纳入糖尿病、周围血管病、慢性肾脏病以及其他动脉粥样硬化性疾病的原因相同,尽管尚缺乏在所有人群或患者中风险增高的统一证据。再次,缺血性卒中的大动脉粥样硬化性卒中亚型与其他这些疾病的病理生理学机制相同。将卒中纳入高危因素将导致高危人群的数量扩大约10%。然而,由于卒中的异质性,尚不确定其他卒中亚型,包括出血性卒中以及非动脉粥样硬化性卒中亚型,是否应被视为具有相同水平的风险,因此有待进一步研究。鉴于卒中对残疾和死亡的影响、卒中与其他血管性疾病预防措施的相似性以及卒中在某些人群中较冠状动脉疾病更高的重要性,将卒中、心肌梗死和猝死纳入心血管事件风险预测工具的转归预测因素是合适的。美国以外的指南常常将卒中患者纳入心血管高危人群,并将卒中作为心脏终点的一个相关转归事件。结论动脉粥样硬化性卒中患者应被纳入会进一步发生冠状动脉粥样硬化事件的高危患者(10年≥20%)。是否应纳入非动脉粥样硬化卒中亚型尚不确定。对于一级预防,缺血性卒中应被纳入绝对风险评估方案的心血管疾病转归事件。将动脉粥样硬化性卒中作为一个高危因素或者更宽泛地将缺血性卒中视作一种转归事件纳入,可能对心血管病的预防具有重要意义,因为被评定为高危风险的患者数量将大幅增加。Daniel T. Lackland Mitchell S.V. Elkind Ralph D'Agostino Sr Mandip S. Dhamoon David C. Goff Jr Randall T. Higashida Leslie A. McClure Pamela H. Mitchell Ralph L. Sacco Cathy A. Sila Sidney C. Smith Jr David Tanne David L. Tirschwell Emmanuel Touze Lawrence R. Wechsler 4:~ 尤寿江(译) 于海龙(译) 刘慧慧(译) 张霞(译) 刘春风(译) 2012国际脑血管病杂志2012,20,11:13
3Systematic review of safety and efficacy of therapeutic endoscopic-retrograde-cholangiopancreatography during pregnancy including studies of radiation-free therapeutic endoscopic-retrograde-cholangiopancreatography显示文摘AIM To systematically review safety/efficacy of therapeutic endoscopic-retrograde-cholangiopancreatography(ERCP) performed during pregnancy, considering fetal viability, fetal teratogenicity, premature delivery, and future postpartum development of the infant.METHODS Systematic computerized literature search performed using PubMed with the key words 'ERCP' and 'pregnancy'. Two clinicians independently reviewed the literature, and decided on which articles to incorporate in this review based on consensus and preassigned priorities. Large clinical trials, meta-analyses, systematic reviews, and controlled trials were assigned higher priority than review articles or small clinical series, and individual case reports were assigned lowest priority. Dr. Cappell has formal training and considerable experience in conducting systematic reviews, with 4 published systematic reviews in peer-reviewed journals indexed in PubM ed during the last 2 years, and with a PhD in neurophysiology that involved 5 years of training and research in biomedical statistics.RESULTS Advances in imaging modalities, including abdominal ultrasound, MRCP, and endoscopic ultrasound, have generally obviated the need for diagnostic ERCP in nonpregnant and pregnant patients. Clinical experience with performing ERCP during pregnancy is burgeoning, with > 500 cases of therapeutic ERCP reported in the literature, aside from a national registry study of 58 patients. These studies show that therapeutic ERCP has a very high rate of technical success in clearing the bile duct of gallstones, and has a relatively low and acceptable rate of maternal and fetal complications. The great majority of births after therapeutic ERCP are full-term, have normal birth weights, and are healthy. A recent trend is performing ERCP without radiation to eliminate radiation teratogenicity. Systematic literature review reveals 147 cases of ERCP without fluoroscopy in 8 clinical series. These studies demonstrate extremely high technical success in endoscopically removing choledocholithiasis, favorable maternal outcomes with rare maternal ERCP complications, and excellent fetal outcomes. ERCP without fluoroscopy generally confirms proper biliary cannulation by aspiration of yellow bile per sphincterotome or leakage of yellow bile around an inserted guide-wire.CONCLUSION This systematic literature review reveals ERCP is relatively safe and efficacious during pregnancy, with relatively favorable maternal and fetal outcomes after ERCP. Recommendations are provided about ERCP indications, special ERCP techniques during pregnancy, and prospects for future research.Mitchell S Cappell Stavros Nicholas Stavropoulos David Friedel 2018World Journal of Gastrointestinal Endoscopy2018,10,10:8
4Stricter national standards are required for credentialing of endoscopic-retrograde-cholangiopan-creatography in the United States显示文摘Endoscopic-retrograde-cholangiopancreatography(ERCP) is now a vital modality with primarily therapeutic and occasionally solely diagnostic utility for numerous biliary/pancreatic disorders. It has a significantly steeper learning curve than that for other standard gastrointestinal(GI) endoscopies, such as esophagogastroduodenoscopy or colonoscopy, due to greater technical difficulty and higher risk of complications. Yet, GI fellows have limited exposure to ERCP during standard-three-year-GI-fellowships because ERCP is much less frequently performed than esophagogastroduodenoscopy/colonoscopy. This led to adding an optional year of training in therapeutic endoscopy. Yet many graduates from standard three-year-fellowships without advanced training intensely pursue independent/unsupervised ERCP privileges despite inadequate numbers of performed ERCPs and unacceptably low rates of successful selective cannulation of desired(biliary or pancreatic) duct. Hospital credentialing committees have traditionally performed ERCP credentialing, but this practice has led to widespread flouting of recommended guidelines(e.g., planned privileging of applicant with 20% successful cannulation rate, or after performing only 7 ERCPs);and intense politicking of committee members by applicants, their practice groups, and potential competitors. Consequently, some gastroenterologists upon completing standard fellowships train and learn ERCP 'on the job' during independent/unsupervised practice, which can result in bad outcomes: high rates of failed bile duct cannulation. This severe clinical problem is indicated by publication of ≥ 12 ERCP competency studies/guidelines during last 5 years. However, lack of mandatory, quantitative, ERCP credentialing criteria has permitted neglect of recommended guidelines. This work comprehensively reviews literature on ERCP credentialing;reviews rationales for proposed guidelines;reports problems with current system;and proposes novel criteria for competency. This work advocates for mandatory, national, written,minimum, quantitative, standards, including cognitive skills(possibly assessed by a nationwide examination), and technical skills, assessed by number performed(≥ 200-250 ERCPs), types of ERCPs, success rate(approximately ≥ 90%cannulation of desired duct), and letters of recommendation by program director/ERCP mentor. Mandatory criteria should ideally not be monitored by a hospital committee subjected to intense politicking by applicants, their employers, and sometimes even competitors, but an independent national entity,like the National Board of Medical Examiners/American Board of Internal Medicine.Mitchell S Cappell David M Friedel 2019World Journal of Gastroenterology2019,25,27:7
5红曲对中度血脂升高美国人调节血脂作用的临床研究显示文摘[目的]评价在饮食控制的情况下红曲(RYRCholestin)对美国高血脂人群的降脂作用和安全性。[方法]开放标记,自身对照,多中心临床试验。187名美国高血脂人群入选(血清低密度脂蛋白胆固醇3.50—4.92mmol/L,总胆固醇5.18—7.25mmol/L;男116人,女71人),162入完成试验。在整个试验中受试者遵照美国国家胆固醇教育计划的饮食要求。试验的前4周仅控制饮食,第5周至第12周连续服用8周RYRCholestin(每日2.4g)。[结果]经前4周饮食控制,血清脂质各指标无显著变化。口服RYRCholestin8周后,血清总胆固醇、低密度脂蛋白胆固醇和三酰甘油分别降低16.6%,24.O%和25.2%,高密度脂蛋白胆固醇升高14.3%(P〈0.001)。显效率为79.0%,有效率为97.5%。停服14d(2周)后,血脂各指标回到试验前水平。试验中共发现可能与服用产品相关的、轻度的29项不良反应。[结论]RYRCholestin的耐受性良好,它可降低血清总胆固醇、低密度脂蛋白胆固醇和三酰甘油,升高血清高密度脂蛋白胆固醇。停服2用后受试者的血脂各项指标均恢复到试验前水平。陆继红 Kermit Bonovich Harry Colfer Michael Davidson Carlos A.Dujovne David L.Fried Mitchell Greenspan Ronald P.Karlsberg Stephen P.King Craig F.LaForce Marc Litt J.Robert McGhee 曾润海 朱佳石 谈宁芝 2013上海预防医学2013,25,9:5
6蔬菜种植户间仍是差序格局下的特殊信任关系吗——某高山反季节蔬菜基地的实证研究显示文摘本文首先采用社会网络分析方法,以武陵山区某高山反季节蔬菜基地为例,分析当前蔬菜种植户群体的信任关系构成。然后结合中国近代社会历史和已有国内外研究,得出当前蔬菜种植户群体的信任关系特点及对合作行为产生的启示。章德宾 青平 Paul David Mitchell 2015农业经济问题2015,36,12:5
7Photonic microwave true time delays for phased array antennas using a 49 GHz FSR integrated optical micro-comb source[Invited]显示文摘We demonstrate significantly improved performance of a microwave true time delay line based on an integrated optical frequency comb source. The broadband micro-comb(over 100 nm wide) features a record low free spectral range(FSR) of 49 GHz, resulting in an unprecedented record high channel number(81 over the C band)—the highest number of channels for an integrated comb source used for microwave signal processing. We theoretically analyze the performance of a phased array antenna and show that this large channel count results in a high angular resolution and wide beam-steering tunable range. This demonstrates the feasibility of our approach as a competitive solution toward implementing integrated photonic true time delays in radar and communications systems.XINGYUAN Xu JIAYANG Wu THACH G.NGUYEN TANIA MOEIN SAI T.CHU BRENT E.LITTLE ROBERTO MORANDOTTI ARNAN MITCHELL DAVID J.Moss 2018Photonics Research2018,6,5:4
8Clinical End Points in Coronary Stent Trials: A Case for Standardized Definitions显示文摘Donald E. Cutlip Stephan Windecker Roxana Mehran Ashley Boam David J. Cohen Gerrit-Anne van Es P Gabriel Steg Marie-angèle Morel Laura Mauri Pascal Vranckx Eugene McFadden Alexandra Lansky Martial Hamon Mitchell W. Krucoff Patrick W. Serruys 2007Circulation2007,,17:4
9Efficacy of boceprevir, an NS3 protease inhibitor, in combination with peginterferon alfa-2b and ribavirin in treatment-naive patients with genotype 1 hepatitis C infection (SPRINT-1): an open-label, randomised, multicentre phase 2 trial显示文摘Paul Y Kwo Eric J Lawitz Jonathan McCone Eugene R Schiff John M Vierling David Pound Mitchell N Davis Joseph S Galati Stuart C Gordon Natarajan Ravendhran Lorenzo Rossaro Frank H Anderson Ira M Jacobson Raymond Rubin Kenneth Koury Lisa D Pedicone Clifford 2010The Lancet2010,,9742:3
10Initial Management of Acute Upper Gastrointestinal Bleeding: From Initial Evaluation up to Gastrointestinal Endoscopy显示文摘Mitchell S. Cappell David Friedel 2008Medical Clinics of North America2008,,3:3
11Models of drug-induced liver injury for evaluation of phytotherapeutics and other natural products显示文摘Hartmut Jaeschke C. David Williams Mitchell R. McGill Yuchao Xie Anup Ramachandran 2013Food and Chemical Toxicology2013,,:3
12Herbal extracts as hepatoprotectants against acetaminophen hepatotoxicity显示文摘Many plant-derived natural products have the potential to be hepatoprotective and therefore can be used to treat acute and chronic liver diseases. The challenge is to identify the most promising compounds and evaluate their protective mechanism. In a recently published article, Wang et al evaluated extracts of the plant Gentiana manshurica Kitagawa (GM) in a model of acetaminophen hepatotoxicity. The authors concluded that GM is hepatoprotective against acetaminopheninduced liver injury due to its antioxidant properties and anti-apoptotic capacity. We would like to discuss the limitations of this experimental approach and question the conclusion based on the data presented in this manuscript and the published literature.Hartmut Jaeschke C David Williams Mitchell R McGill Anwar Farhood 2010World Journal of Gastroenterology2010,16,19:3
13Sofosbuvir with pegylated interferon alfa-2a and ribavirin for treatment-naive patients with hepatitis C genotype-1 infection (ATOMIC): an open-label, randomised, multicentre phase 2 trial显示文摘Kris V Kowdley Eric Lawitz Israel Crespo Tarek Hassanein Mitchell N Davis Michael DeMicco David E Bernstein Nezam Afdhal John M Vierling Stuart C Gordon Jane K Anderson Robert H Hyland Hadas Dvory-Sobol Di An Robert G Hindes Efsevia Albanis William T Symo 2013The Lancet2013,,9883:3
14Gastrointestinal endoscopy in the pregnant woman显示文摘About 20000 gastrointestinal endoscopies are performed annually in America in pregnant women. Gastrointestinal endoscopy during pregnancy raises the critical issue of fetal safety in addition to patient safety. Endoscopic medications may be potentially abortifacient or teratogenic. Generally, Food and Drug Administration category B or C drugs should be used for endoscopy. Esophagogastroduodenoscopy(EGD) seems to be relatively safe for both mother and fetus based on two retrospective studies of 83 and 60 pregnant patients. The diagnostic yield is about 95% when EGD is performed for gastrointestinal bleeding. EGD indications during pregnancy include acute gastrointestinal bleeding, dysphagia > 1 wk, or endoscopic therapy. Therapeutic EGD is experimental due to scant data, but should be strongly considered for urgent indications such as active bleeding. One study of 48 sigmoidoscopies performed during pregnancy showed relatively favorable fetal outcomes, rare bad fetal outcomes, and bad outcomes linked to very sick mothers. Sigmoidoscopy should be strongly considered for strong indications,including significant acute lower gastrointestinal bleeding, chronic diarrhea, distal colonic stricture, suspected inflammatory bowel disease flare, and potential colonic malignancy. Data on colonoscopy during pregnancy are limited. One study of 20 pregnant patients showed rare poor fetal outcomes. Colonoscopy is generally experimental during pregnancy, but can be considered for strong indications: known colonic mass/stricture, active lower gastrointestinal bleeding, or colonoscopic therapy. Endoscopic retrograde cholangiopancreatography(ERCP) entails fetal risks from fetal radiation exposure. ERCP risks to mother and fetus appear to be acceptable when performed for ERCP therapy, as demonstrated by analysis of nearly 350 cases during pregnancy. Justifiable indications include symptomatic or complicated choledocholithiasis, manifested by jaundice, cholangitis, gallstone pancreatitis, or dilated choledochus. ERCP should be performed by an expert endoscopist, with informed consent about fetal radiation risks, minimizing fetal radiation exposure, and using an attending anesthesiologist. Endoscopy is likely most safe during the second trimester of pregnancy.David Friedel Stavros Stavropoulos Shahzad Iqbal Mitchell S Cappel 2014World Journal of Gastrointestinal Endoscopy2014,6,5:3
15Acute Nonvariceal Upper Gastrointestinal Bleeding: Endoscopic Diagnosis and Therapy显示文摘Mitchell S. Cappell David Friedel 2008Medical Clinics of North America2008,,3:2
16Hepatocellular carcinoma after Iocoregional therapy:Magnetic resonance imaging findings in falsely negative exams显示文摘AIM:To elucidate causes for false negative magnetic resonance imaging(MRI)exams by identifying imaging characteristics that predict viable hepatocellular carcinoma(HCC)in lesions previously treated with locoregional therapy when obvious findings of recurrence are absent.METHODS:This retrospective institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study included patients who underwent liver transplantation at our center between 1/1/2000 and 12/31/2012 after being treated for HCC with locoregional therapy.All selected patients had a contrast-enhanced MRI after locoregional therapy within 90 d of transplant that was prospectively interpreted as without evidence of residual or recurrenttumor.Retrospectively,2 radiologists,blinded to clinica and pathological data,independently reviewed the pre transplant MRIs for 7 imaging features.Liver explan histopathology provided the reference standard,with clinically significant tumor defined as viable tumor≥1.0cm in maximum dimension.Fisher’s exact test was firs performed to identify significant imaging features.RESULTS:Inclusion criteria selected for 42 patients with 65 treated lesions.Fourteen of 42 patients(33%and 16 of 65 treated lesions(25%)had clinically significant viable tumor on explant histology.None o the 7 imaging findings examined could reliably and reproducibly determine which treated lesion had viable tumor when the exam had been prospectively read as without evidence of viable HCC.CONCLUSION:After locoregional therapy some treated lesions that do not demonstrate any MRI evidence o HCC will contain viable tumor.As such even patients with a negative MRI following treatment should receive regular short-term imaging surveillance because some have occult viable tumor.The possibility of occult tumo should be a consideration when contemplating any action which might delay liver transplant.David Becker-Weidman Jesse M Civan Sandeep P Deshmukh Christopher G Roth Steven K Herrine Laurence Parker Donald G Mitchell 2016World Journal of Hepatology2016,8,16:2
17Application of positron emission tomography/computed tomography in radiation treatment planning for head and neck cancers显示文摘18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas(SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.Musaddiq J Awan Farzan Siddiqui David Schwartz Jiankui Yuan Mitchell Machtay Min Yao 2015World Journal of Radiology2015,7,11:2
18Current issues with acetaminophen hepatotoxicity—A clinically relevant model to test the efficacy of natural products显示文摘Hartmut Jaeschke Mitchell R. McGill C. David Williams Anup Ramachandran 2011Life Sciences2011,,17:2
19Salt Accumulation and Physiology of Naturally Occurring Grasses in Saline Soils in Australia显示文摘Salinity is a major soil contamination problem in Australia. To explore salinity remediation, we evaluated the concentrations of sodium(Na), potassium(K), magnesium(Mg), and calcium(Ca) in roots and shoots and in the supporting soil of the naturally occurring grasses, Cynodon dactylon and Thinopyrum ponticum, at two salt-affected sites, Gumble and Cundumbul in central-western New South Wales, Australia. The physiological parameters of the two grass species, including net photosynthetic rate(Pn), stomatal conductance(gs), and intercellular CO2 concentration(Ci), were investigated using one mature leaf from C. dactylon and T. ponticum populations. Increasing salinity levels in the topsoil had a significant influence on Ciand gs, whereas no significant effect occurred on Pn in C. dactylon and T. ponticum. The Pn values in C. dactylon and T. ponticum were greater at Cundumbul than at Gumble.The greater Mg concentration facilitated greater Pn in C. dactylon and T. ponticum populations at Cundumbul than Gumble. With increasing salinity levels in the soil, Na accumulation increased in C. dactylon and T. ponticum. The ratio between K and Na was > 1in roots and shoots of both populations irrespective of the sites. Bioaccumulation factor(BF) and translocation factor(TF) results revealed that K and Na translocations were significantly higher in T. ponticum than in C. dactylon, whereas Ca and Mg translocations were significantly higher in C. dactylon than in T. ponticum. Accumulation of Na, K, Mg, and Ca ions was higher in T. ponticum than in C. dactylon; therefore, we suggest that T. ponticum as a greater salt accumulator than C. dactylon could be used for revegetation and phytoremediation of the salt-affected soils.Mohammad S.I.BHUIYAN Anantanarayanan RAMAN Dennis S.HODGKINS David MITCHELL Helen I.NICOL 2015Pedosphere2015,25,4:2
20A Phase II Trial of Neoadjuvant Chemoradiation and Local Excision for T2N0 Rectal Cancer: Preliminary Results of the ACOSOG Z6041 Trial显示文摘Julio Garcia-Aguilar MD PhD Qian Shi PhD Charles R. Thomas MD Emily Chan MD PhD Peter Cataldo MD Jorge Marcet MD David Medich MD Alessio Pigazzi MD Samuel Oommen MD Mitchell C. Posner MD 2012Annals of Surgical Oncology2012,,2:2
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