维普中文期刊产品整合服务
6409篇 您的检索式:作者名="STEPHAN"
    题名 作者 年代 出处 被引量
1The Open Quantum Materials Database (OQMD): assessing the accuracy of DFT formation energies显示文摘The Open Quantum Materials Database(OQMD)is a high-throughput database currently consisting of nearly 300,000 density functional theory(DFT)total energy calculations of compounds from the Inorganic Crystal Structure Database(ICSD)and decorations of commonly occurring crystal structures.To maximise the impact of these data,the entire database is being made available,without restrictions,at www.oqmd.org/download.In this paper,we outline the structure and contents of the database,and then use it to evaluate the accuracy of the calculations therein by comparing DFT predictions with experimental measurements for the stability of all elemental ground-state structures and 1,670 experimental formation energies of compounds.This represents the largest comparison between DFT and experimental formation energies to date.The apparent mean absolute error between experimental measurements and our calculations is 0.096 eV/atom.In order to estimate how much error to attribute to the DFT calculations,we also examine deviation between different experimental measurements themselves where multiple sources are available,and find a surprisingly large mean absolute error of 0.082 eV/atom.Hence,we suggest that a significant fraction of the error between DFT and experimental formation energies may be attributed to experimental uncertainties.Finally,we evaluate the stability of compounds in the OQMD(including compounds obtained from the ICSD as well as hypothetical structures),which allows us to predict the existence of~3,200 new compounds that have not been experimentally characterised and uncover trends in material discovery,based on historical data available within the ICSD.Scott Kirklin James E Saal Bryce Meredig Alex Thompson Jeff W Doak Muratahan Aykol Stephan Rühl Chris Wolverton 2015npj Computational Materials2015,,1:62
2Hepatitis B virus taxonomy and hepatitis B virus genotypes显示文摘Hepatitis B virus(HBV) is a member of the hepadnavirus family.Hepadnaviruses can be found in both mammals(orthohepadnaviruses) and birds(avihepadnaviruses).The genetic variability of HBV is very high.There are eight genotypes of HBV and three clades of HBV isolates from apes that appear to be additional genotypes of HBV.Most genotypes are now divided into subgenotypes with distinct virological and epidemiological properties.In addition,recombination among HBV genotypes increases the variability of HBV.This review summarises current knowledge of the epidemiology of genetic variability in hepadnaviruses and,due to rapid progress in the field,updates several recent reviews on HBV genotypes and subgenotypes.Stephan Schaefer 2007World Journal of Gastroenterology2007,13,1:42
3Immunopathogenesis of inflammatory bowel disease显示文摘Crohn’s disease and ulcerative colitis are chronic relapsing immune mediated disorders that results from an aberrant response to gut luminal antigen in genetically susceptible host. The adaptive immune response that is then triggered was widely considered to be a T-helper-1 mediated condition in Crohn’s disease and T-helper-2 mediated condition in ulcerative colitis. Recent studies in animal models, genome wide association, and basic science has provided important insights in in the immunopathogenesis of inflammatory bowel disease, one of which was the characterization of the interleukin-23/Th-17 axis.David Q Shih Stephan R Targan 2008World Journal of Gastroenterology2008,14,3:44
4Viral and cellular determinants involved in hepadnaviral entry显示文摘Hepadnaviridae is a family of hepatotropic DNA viruses that is divided into the genera orthohepadnavirus of mammals and avihepadnavirus of birds.All members of this family can cause acute and chronic hepatic infec-tion,which in the case of human hepatitis B virus(HBV) constitutes a major global health problem.Although our knowledge about the molecular biology of these highly liver-specific viruses has profoundly increased in the last two decades,the mechanisms of attachment and productive entrance into the differentiated host hepa-tocytes are still enigmatic.The difficulties in studying hepadnaviral entry were primarily caused by the lack of easily accessible in vitro infection systems.Thus,for more than twenty years,differentiated primary hepato-cytes from the respective species were the only in vitro models for both orthohepadnaviruses(e.g.HBV) and avihepadnaviruses(e.g.duck hepatitis B virus [DHBV]).Two important discoveries have been made recently re-garding HBV:(1) primary hepatocytes from tree-shrews;i.e.,Tupaia belangeri,can be substituted for primary hu-man hepatocytes,and(2) a human hepatoma cell line(HepaRG) was established that gains susceptibility for HBV infection upon induction of differentiation in vitro.A number of potential HBV receptor candidates have been described in the past,but none of them have been confirmed to function as a receptor.For DHBV and prob-ably all other avian hepadnaviruses,carboxypeptidase D(CPD) has been shown to be indispensable for infection,although the exact role of this molecule is still under debate.While still restricted to the use of primary duck hepatocytes(PDH),investigations performed with DHBV provided important general concepts on the first steps of hepadnaviral infection.However,with emerging dataobtained from the new HBV infection systems,the hope that DHBV utilizes the same mechanism as HBV only partially held true.Nevertheless,both HBV and DHBV in vitro infection systems will help to:(1) functionally dis-sect the hepadnaviral entry pathways,(2) perform re-verse genetics(e.g.test the fitness of escape mutants),(3) titrate and map neutralizing antibodies,(4) improve current vaccines to combat acute and chronic infections of hepatitis B,and(5) develop entry inhibitors for future clinical applications.Dieter Glebe Stephan Urban 2007World Journal of Gastroenterology2007,13,1:35
5The role and modulation of autophagy in experimental models of myocardial ischemia-reperfusion injury显示文摘称为 autophagy 品质上的一个生理的序列由移开蛋白质总数和损坏细胞质的成分决定细胞的生存能力,并且显著地作出贡献到心肌的 ischemia-reperfusion (I/R ) 的度损害。这紧安排的分解代谢的细胞的 ‘ housekeeping’过程向房间提供精力的新来源适应紧张的条件。当支持幸存的机制,而是增加的证据建议它能也导致房间的遗赠,这个过程首先被描述。Autophagy 包括心肌的 I/R 损害在多重心脏的条件的致病被含有。然而,争论至于 autophagy 是否充当保护的机制或在心贡献 I/R 损害的有害效果坚持。这争吵可以在试验性的模型和种包括可变性源自几个因素,并且方法论过去常估计 autophagy。这评论在向操作 autophagy 显著地在压力大多数的条件下面增加心脏的 myocytes 的幸存受到 I/R,和成长兴趣的孤立的心脏的房间在 autophagy 的调整和角色上提供更新的知识是 I/R 损害。这的不安 evolutionarily 保存了细胞内部的清洁的 autophagy 机制,由指向的调整通过在其它之中, rapamycin ( mTOR )的哺乳动物的目标禁止者,腺苷 激活monophosphate 的蛋白质 kinase ( AMPK )调节的人,钙降低代理人, resveratrol , longevinex , sirtuin 使活跃之物, proapoptotic 基因 Bnip3 , IP3 和 lysosome 禁止者,可以对 I/R 授与抵抗到心房间导致的房间死亡。因此,在质问心肌层的 autophagy 的治疗学的操作可以有益于梗塞以后的心脏的愈合并且改变。Carol Chen-Scarabelli Pratik R. Agrawal Louis Saravolatz Cadigia Abuniat Gabriele Scarabelli Anastasis Stephanou Leena Loomba Jagat Narula Tiziano M. Scarabelli Richard Knight 2014Journal of Geriatric Cardiology2014,11,4:37
6Evaluation of acoustic radiation force impulse imaging for determination of liver stiffness using transient elastography as a reference显示文摘AIM: To evaluate cut-off values and performance of acoustic radiation force impulse imaging (ARFI) using transient elastography [FibroScan■ (FS)] as a reference. METHODS: Six hundred and six patients were enrolled in this study.All patients underwent liver stiffness measurement with FS (FS-LS) and ARFI (with shear wave velocity quantification; ARFI-SWV) and the performance of ARFI in comparison to FS was determined. Sixtyeight patients underwent liver biopsy. RESULTS: Significantly higher success rates for the determination of liver stiffness were found using ARFI as compared to FS [604/606 (99.7%) vs 482/606 (79.5%); P < 0.001]. ARFI-SWV correlated significantly with FS-LS (r = 0.920, P < 0.001). ARFI-SWV increased significantly with the stage of fibrosis (1.09 ± 0.13 m/s for patients with no significant fibrosis (FS-LS < 7.6 kPa); 1.46 ± 0.27 m/s for patients with significant liver fibrosis (7.6 < FS-LS ≤ 13.0 kPa); and 2.55 ± 0.77 m/s for patients with liver cirrhosis (FS-LS > 13.0 kPa)). ARFI-SWV cut-off values were identified for no significant fibrosis (1.29 m/s; sensitivity 91.4% and specificity 92.6%) and for liver cirrhosis (1.60 m/s; sensitivity 92.3% and specificity 96.5%). The optimal cut-off value for predicting liver fibrosis (F ≥ 2) was 1.32 m/s (sensitivity 87.0% and specificity 80.0%) and for liver cirrhosis (F4) 1.62 m/s (sensitivity 100% and specificity 85.7%), for patients who underwent liver biopsy. An excellent inter-and intraobserver reproducibility was observed for ARFI-SWV determinations. CONCLUSION: An ARFI-SWV cut-off value of 1.29 m/s seems to be optimal for patients with no significant liver fibrosis and 1.60 m/s for patients with liver cirrhosis.Gerald Kircheis Abdurrahman Sagir Christoph Vogt Stephan vom Dahl Ralf Kubitz Dieter Hussinger 2012World Journal of Gastroenterology2012,18,10:30
7Development of early gastric cancer 4 and 5 years after complete remission of Helicobacter pyloriassociated gastric low-grade marginal zone B-cell lymphoma of MALT type显示文摘AIM To report 3 of 120 patients on the German MALT lymphoma trial with H. pYlori-associated gastric MALT Iymphoma who developed early gastric cancer 4 and 5 years, after complete Iymphoma remission following cure of H. pylori infection.PATIENTS AND RESULTS Three patients (two men, 74 and 70 years; one women, 77 years)with H. pylori -associated low-grade MALTlymphoma achieved complete lymphoma remission after being cured. Surveillance endoscopies were performed twice a year in accordance to the protocol. Four years aftercomplete lymphoma remission in two patients,and after 5 years in the other, early gastric adenocarcinoma of the mucosa-type, type Ⅱ a and type Ⅱ c, respectively, was detetcted,which were completely removed by endoscopic mucosa resection. in one patient, the gastric cancer was diagnosed at the same location as the previous. MALT lymphoma, in the other patients it was detected at different sites of the stomach distant from location of the previous MALT lymphoma. The patients were H. pylori negative during the whole follow-up time.CONCLUSION These findings strengthen the importance of regular long-term follow-up endoscopies in patients with complete remission of gastric MALT lymphoma after cure of H.pylori infection. Furthermore, gastric adenocarcinoma may develop despite eradication of H. pylori.Andrea Morgner Stephan Miehlke Manfred Stolte Andreas Neubauer Birgit Alpen Christian Thiede Hermann Klann Franz-Xaver Hierlmeier Christian Ell Gerhard Ehninger Ekkehard Bayerdorffer 2001World Journal of Gastroenterology2001,7,2:28
8基于深度学习与图像处理的玉米茎秆识别方法与试验显示文摘以识别玉米秧苗茎秆为目标,采用云台搭载电荷耦合器件(CCD)相机获得玉米秧苗图像,采用Label Image插件制作了玉米秧苗的标记与标签。基于深度学习框架Tensor Flow搭建了多尺度分层特征的卷积神经网络模型,应用4倍膨胀的单位卷积核,获得了玉米秧苗图像的识别模型,其识别准确率为99.65%。将已知玉米秧苗图像划分为最佳子块,求取了各个子块的最佳二值化阈值。选取6种杂草密度在每天5个时间段进行为期3 d的试验,共采集了10800幅图像。试验结果显示,对玉米秧苗茎秆的平均识别准确率为98.93%,且光照条件与田间杂草密度对识别结果没有显著影响(P>0.05)。刘慧力 贾洪雷 王刚 GLATZEL Stephan 袁洪方 黄东岩 2020农业机械学报2020,51,4:25
9The woodchuck as an animal model for pathogenesis and therapy of chronic hepatitis B virus infection显示文摘This review describes the woodchuck and the woodchuck hepatitis virus (WHV) as an animal model for pathogenesis and therapy of chronic hepatitis B virus (HBV) infection and disease in humans. The establishment of woodchuck breeding colonies, and use of laboratory-reared woodchucks infected with defined WHV inocula, have enhanced our understanding of the virology and immunology of HBV infection and disease pathogenesis, including major sequelae like chronic hepatitis and hepatocellular carcinoma. The role of persistent WHV infection and of viral load on the natural history of infection and disease progression has been firmly established along the way. More recently, the model has shed new light on the role of host immune responses in these natural processes, and on how the immune system of the chronic carrier can be manipulated therapeutically to reduce or delay serious disease sequelae through induction of the recovery phenotype. The woodchuck is an outbred species and is not well defined immunologically due to a limitation of available host markers. However, the recent development of several key host response assays for woodchucks provides experimental opportunities for further mechanistic studies of outcome predictors in neonatal- and adult-acquired infections. Understanding the virological and immunological mechanisms responsible for resolution of self-limited infection, andfor the onset and maintenance of chronic infection, will greatly facilitate the development of successful strategies for the therapeutic eradication of established chronic HBV infection. Likewise, the results of drug efficacy and toxicity studies in the chronic carrier woodchucks are predictive for responses of patients chronically infected with HBV. Therefore, chronic WHV carrier woodchucks provide a well-characterized mammalian model for preclinical evaluation of the safety and efficacy of drug candidates, experimental therapeutic vaccines, and immunomodulators for the treatment and prevention of HBV disease sequelae.Stephan Menne Paul J Cote 2007World Journal of Gastroenterology2007,13,1:22
10Genetics of hepatocellular carcinoma显示文摘The completely assembled human genome has made it possible for modern medicine to step into an era rich in genetic information and high-throughput genomic analysis. These novel and readily available genetic resources and analytical tools may be the key to unravel the molecular basis of hepatocellular carcinoma (HCC). Moreover, since an efficient treatment for this disease is lacking, further understanding of the genetic background of HCC will be crucial in order to develop new therapies aimed at selected targets. We report on the current status and recent developments in HCC genetics. Special emphasis is given to the genetics and regulation of major signalling pathways involved in HCC such as p53, Wnt- signalling, TGFβ, Ras, and Rb pathways. Furthermore, we describe the influence of chromosomal aberrations as well as of DNA methylation. Finally, we report on the rapidly developing field of genomic expression profiling in HCC, mainly by microarray analysis.Andreas Teufel Frank Staib Stephan Kanzler Arndt Weinmann Henning Schulze-Bergkamen Peter R Galle 2007World Journal of Gastroenterology2007,13,16:21
11Comparative cytotoxicity of fourteen trivalent and pentavalent arsenic species determined using real-time cell sensing显示文摘The occurrence of a large number of diverse arsenic species in the environment and in biological systems makes it important to compare their relative toxicity. The toxicity of arsenic species has been examined in various cell lines using different assays, making comparison difficult. We report real-time cell sensing of two human cell lines to examine the cytotoxicity of fourteen arsenic species: arsenite(As~Ⅲ), monomethylarsonous acid(MMA~Ⅲ) originating from the oxide and iodide forms, dimethylarsinous acid(DMA~Ⅲ), dimethylarsinic glutathione(DMAG~Ⅲ), phenylarsine oxide(PAO~Ⅲ), arsenate(AsV), monomethylarsonic acid(MMA~Ⅴ), dimethylarsinic acid(DMA~Ⅴ),monomethyltrithioarsonate(MMTTA~Ⅴ), dimethylmonothioarsinate(DMMTA~Ⅴ),dimethyldithioarsinate(DMDTA~Ⅴ), 3-nitro-4-hydroxyphenylarsonic acid(Roxarsone, Rox),and 4-aminobenzenearsenic acid(p-arsanilic acid, p-ASA). Cellular responses were measured in real time for 72 hr in human lung(A549) and bladder(T24) cells. IC50 values for the arsenicals were determined continuously over the exposure time, giving rise to IC50 histograms and unique cell response profiles. Arsenic accumulation and speciation were analyzed using inductively coupled plasma-mass spectrometry(ICP-MS). On the basis of the 24-hr IC50 values, the relative cytotoxicity of the tested arsenicals was in the following decreasing order: PAO~Ⅲ? MMA~Ⅲ≥ DMA~Ⅲ≥ DMAG~Ⅲ≈ DMMTA~Ⅴ≥ As~Ⅲ? MMTTA~Ⅴ> AsV> DMDTA~Ⅴ>DMA~Ⅴ> MMA~Ⅴ≥ Rox ≥ p-ASA. Stepwise shapes of cell response profiles for DMA~Ⅲ, DMAG~Ⅲ,and DMMTA~Ⅴcoincided with the conversion of these arsenicals to the less toxic pentavalent DMA~Ⅴ. Dynamic monitoring of real-time cellular responses to fourteen arsenicals provided useful information for comparison of their relative cytotoxicity.Birget Moe Hanyong Peng Xiufen Lu Baowei Chen Lydia W.L.Chen Stephan Gabos Xing-Fang Li X.Chris Le 2016Journal of Environmental Sciences2016,28,11:19
12相变材料微胶囊悬浮液在矩形小通道内层流流动传热的实验显示文摘本文进行了对比性的实验,以研究相变材料微胶囊(MEPCM)-水悬浮液在水力直径为2.71mm的矩形小通道内的层流流动传热性能。实验中用的MEPCM颗粒的平均粒径为4.97μm,与蒸馏水混合制备成质量浓度范围为0~20%的MEPCM-水悬浮液。对比性的实验是指,在相同的悬浮液质量流量和热力条件下,使用不同浓度的MEPCM悬浮液进行传热实验。实验发现,MEPCM悬浮液的冷却性能严重依赖于悬浮液的质量流量和悬浮液的质量浓度。质量浓度为5%的悬浮液在在整个质量流量范围内总是表现出比水好的冷却性能,它对应的是更低的壁面温度以及更好的传热系数。而对于更高质量浓度的悬浮液,在低质量流量的情况下,它们具有很好的冷却性能;而在高质量流量的情况下,它们表现出的冷却性能比水更差,它们对应更高的壁面温度以及更低的Nusselt数。饶宇 Frank Dammel Peter Stephan 林贵平 2006航空动力学报2006,21,6:18
13Update on autoimmune hepatitis显示文摘Autoimmune hepatitis (AIH) is a necroinflammatory liver disease of unknown etiology that occurs in children and adults of all ages. Characteristics are its autoimmune features,hyperglobulinemia (IgG),and the presence of circulating autoantibodies,as well as a response to immunosuppressant drugs. Current treatment consists of prednisone and azathioprine and in most patients this disease has become very treatable. Over the past 2 years,a couple of new insights into the genetic aspects,clinical course and treatment of AIH have been reported,which will be the focus of this review. In particular,we concentrate on genome-wide microsatellite analysis,a novel mouse model of AIH,the evaluation of a large AIH cohort for overlap syndromes,suggested novel criteria for the diagnosis of AIH,and the latest studies on treatment of AIH with budenoside and mycophenolate mofetil.Andreas Teufel Peter R Galle Stephan Kanzler 2009World Journal of Gastroenterology2009,15,9:17
14Euler-Lagrange/DEM simulation of wood gasification in a bubbling fluidized bed reactor显示文摘We present an Euler–Lagrange method for the simulation of wood gasification in a bubbling fluidized bed. The gas phase is modeled as a continuum using the 2D Navier–Stokes equations and the solid phase is modeled by a Discrete Element Method(DEM)using a soft-sphere approach for the particle collision dynamic. Turbulence is included via a Large-Eddy approach using the Smagorinsky sub-grid model.The model takes into account detailed gas phase chemistry,zero-dimensional modeling of the pyrolysis and gasification of each individual particle,particle shrinkage,and heat and mass transfer between the gas phase and the particulate phase.We investigate the influence of wood feeding rate and compare exhaust gas compositions and temperature results obtained with the model against experimental data of a laboratory scale bubbling fluidized bed reactor.Michael Oevermann Stephan Gerber Frank Behrendt 2009Particuology2009,7,4:15
15Increased resistance of drought by Trichoderma harzianum fungal treatment correlates with increased secondary metabolites and proline content显示文摘Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato(Solanum lycopersicum) infected by Trichoderma harzianum leads to alterations in the biosynthesis of secondary plant metabolites including phytohormones and osmolyte proline under drought stress. Exposure of tomato to drought caused a drastic decline in plant growth and physiological parameters. Tomato inoculated with T. harzianum showed increased root and shoot growth and chlorophyll pigments as compared to uninoculated controls as well as drought stressed plants. Proline and total soluble protein content was increased in plants inoculated with T. harzianum under both normal as well as drought conditions. An obvious increase in phenol and flavonoid content was observed due to T. harzianum. In addition, T. harzianum inoculated plants maintained higher levels of growth regulators indole acetic acid, indole butyric acid, and gibberellic acid under drought stress. Improved secondary metabolites which play an important role in plant stress tolerance by T. harzianum may have coordinately worked for bringing the growth regulation by protecting membranes from reactive oxygen species(ROS) and enhance plant growth through accessing more nutrients by root system.Mona S.Alwhibi Abeer Hashem Elsayed Fathi Abd_Allah Abdulaziz A.Alqarawi Dina Wafi K.Soliman Stephan Wirth Dilfuza Egamberdieva 2017Journal of Integrative Agriculture2017,16,8:15
16Co-expression of CDX2 and MUC2 in gastric carcinomas: Correlations with clinico-pathological parameters and prognosis显示文摘AIM: To evaluate the role of CDX2 homeobox protein as a predictor for cancer progression and prognosis as well as its correlation with MUC2 expression. CDX2 represents a transcription factor for various intestinal genes (including MUC2) and thus an important regulator of intestinal differentiation, which could previously be identified in gastric carcinomas and intestinal metaplasia.METHODS: Formalin-fixed and paraffin-embedded tissues from 190 gastric carcinoma patients were stained with monodonal antibodies recognizing CDX2 and MUC2, respectively. Immunoreactivity was evaluated semiquantitatively and statistical analyses including χ2 tests, uni- and multi-variate survival analyses were performed.RESULTS: CDX2 was mostly expressed in a nuclear or supranuclear pattern, whereas MUC2 showed an almost exclusive supranuclear reactivity. Both antigens were present in >80% of areas exhibiting intestinal metaplasia. An immunoreactivity in >5% of the tumor area was observed in 57% (CDX2) or in 21% (MUC2) of the carcinomas. The presence of both molecules did not correlate with WHO,significantly stronger vlUC2 expression in mucinous tumors). CDX2 correlated with a lower pT and pN stage in the subgroups of intestinal and stage I cancers and was associated with MUC2 positivity. A prognostic impact of CDX2 or MUC2 was not observed. CONCLUSION: CDX2 and MUC2 play an important role in the differentiation of normal, inflamed, and neoplastic gastric tissues. According to our results, loss of CDX2 may represent a marker of tumor progression in early gastric cancer and carcinomas with an intestinal phenotype.Kristina Roessler Stefan P.M(o|¨)nig Paul M.Schneider Franz-Georg Hanisch Stephanie Landsberg Juergen Thiele Arnulf H.H(o|¨)lscher Hans P.Dienes Stephan E.Baldus 2005World Journal of Gastroenterology2005,11,21:15
17MRI-determined fat content of human liver,pancreas and kidney显示文摘AIM:To assess and correlate the lipid content of various organs in obese subjects and in persons with a normal body weight.METHODS:Magnetic resonance spectroscopy and a previously validated gradient echo magnetic resonance imaging method with Dixon's two point technique were used in this study to quantify fat in liver,pancreas as well as kidney.RESULTS:In 36 volunteers with body mass index(BMI) ranging from 20.0 to 42.9 kg/m2,the median fat content of liver,pancreas and kidney was 2.3%(interquartile range:0.2%-7.8%),2.7%(1.0%-6.5%) and 0.7%(0.1%-1.4%),respectively.BMI and subcutaneous fat correlated significantly with liver and pancreas fat content.We show for the first time the significant correlation of liver and pancreas fat content in healthy controls(r = 0.43,P < 0.01).These observations are related to body weight as measured by BMI and the amount of subcutaneous fat.Kidney fat content is very low and correlates with none of the other fat depots.CONCLUSION:Renal lipid accumulation,unlike the coupled accumulations of fat in liver and pancreas,is not observed in obese subjects.Unlike suggestions made in previous studies,renal lipid accumulation appears not to be involved in the pathogenesis of renal disease in humans.Paul E Sijens Mireille A Edens Stephan JL Bakker Ronald P Stolk 2010World Journal of Gastroenterology2010,16,16:14
18Long-term follow-up after complete ablation of Barrett's esophagus with argon plasma coagulation显示文摘AIM: To report the long-term outcome of patients after complete ablation of non-neoplastic Barrett's esophagus (BE) with respect to BE relapse and development of intraepithelial neoplasia or esophageal adenocarcinoma.METHODS: In 70 patients with histologically proven nonneoplastic BE, complete BE ablation was achieved by argon plasma coagulation (APC) and high-dose proton pump inhibitor therapy (120 mg omeprazole daily). Sixty-six patients (94.4%) underwent further surveillance endoscopy. At each surveillance endoscopy four-quadrant biopsies were taken from the neo-squamous epithelium at 2 cm intervals depending on the pre-treatment length of BE mucosa beginning at the neo-Z-line, and from any endoscopically suspicious lesion.RESULTS: The median follow-up of 66 patients was 51 mo (range 9-85 mo) giving a total of 280.5 patient years.A mean of 6 biopsies were taken during surveillance endoscopies. In 13 patients (19.7%) tongues or islands suspicious for BE were found during endoscopy. In 8 of these patients (12.1%) non-neoplastic BE relapse was confirmed histologically giving a histological relapse rate of 3% per year. In none of the patients, intraepithelial neoplasia nor an esophageal adenocarcinoma was detected.Logistic regression analysis identified endoscopic detection of islands or tongues as the only positive predictor of BE relapse (P = 0.0004).CONCLUSION: The long-term relapse rate of nonneoplastic BE following complete ablation with high-power APC is low (3% per year).Ahmed Madisch Stephan Miehike Ekkehard Bayerdoerffer Birgit Wiedemann David Antos Anke Sievert Michael Vieth Manfred Stolte Heinrich Schulz 2005World Journal of Gastroenterology2005,11,8:14
19Therapy of gastric mucosa associated lymphoid tissue lymphoma显示文摘Gastric mucosa associated lymphoid tissue (MALT) lymphoma has recently been incorporated into the World Health Organization (WHO) lymphoma classification, termed as extranodal marginal zone B-cell lymphoma of MALT-type. In about 90% of cases this lymphoma is associated with H pylori infection which has been clearly shown to play a causative role in lymphomagenesis. Although much knowledge has been gained in defining the clinical features, natural history, pathology, and molecular genetics of the disease in the last decade, the optimal treatment approach for gastric MALT lymphomas, especially locally advanced cases, is still evolving. In this review we focus on data for the therapeutic, stage dependent management of gastric MALT lymphoma. Hence, the role of eradication therapy, surgery, chemotherapy and radiotherapy is critically analyzed. Based on these data, we suggest a therapeutic algorithm that might help to better stratify patients for optimal treatment success.Andrea Morgner Renate Schmelz Christian Thiede Manfred Stolte Stephan Miehlke 2007World Journal of Gastroenterology2007,13,26:14
20Promoter methylation status of hMLH1,MGMT,and CDKN2A/p16 in colorectal adenomas显示文摘AIM:To investigate aberrant DNA methylation of CpG islands and subsequent low-or high-level DNA microsatellite instability(MSI)which is assumed to drive colon carcinogenesis. METHODS:DNA of healthy individuals,adenoma(tu-bular or villous/tubulovillous)patients,and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1(hMLH1),Cyclin-dependent kinase inhibitor 2A(CDKN2A/p16),and O-6-methylguanine DNA methyltransferase(MGMT),as well as their rela- tion to MSI. RESULTS:The frequency of promoter methylation for each locus increased in the sequence healthy tissue/adenoma/carcinoma.MGMT showed the highest frequency in each group.MGMT and CDKN2A/p16 presented a statistically significant increase in promoter methylation between the less and more tumorigenic forms of colorectal adenomas(tubular vs tubullovillous and villous adenomas).All patients with tubulovillous/villous adenomas,as well as all colorectal cancer patients,showed promoter methylation in at least one of the examined loci.These findings suggest a potentially crucial role for methylation in the polyp/adenoma to cancer progres- sion in colorectal carcinogenesis.MSI and methylation seem to be interdependent,as simultaneous hMLH1, CDKN2A/p16,and MGMT promoter methylation was present in 8/9 colorectal cancer patients showing the MSI phenotype. CONCLUSION:Methylation analysis of hMLH1,CD- KN2A/p16,and MGMT revealed specific methylation profiles for tubular adenomas,tubulovillous/villous adenomas,and colorectal cancers,supporting the use of these alterations in assessment of colorectal tumorigenesis.Vasiliki Psofaki Chryssoula Kalogera Nikolaos Tzambouras Dimitrios Stephanou Epameinondas Tsianos Konstantin Seferiadis Georgios Kolios 2010World Journal of Gastroenterology2010,16,28:14
返回顶部 每页显示:
共321页 首页 上一页 第1页 下一页 末页 /321 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费