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254篇 您的检索式:作者名="Gerhard J"
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1Intraductal endoscopic radiofrequency ablation for the treatment of hilar non-resectable malignant bile duct obstruction显示文摘AIM: To evaluate the safety and technical success of endoscopic radiofrequency ablation(RFA) for palliative treatment of malignant hilar bile duct obstruction. METHODS: In this study, a recently CE and FDA-approved endoscopic RFA catheter was first tested in an ex vivo pig liver model to study the effect of electrosurgical variables on the extent of the area of induced necrosis. Subsequently, a retrospective analysis was conducted of all patients treated with endoscopic RFA for malignant biliary obstruction at our center between February 2012 and April 2013. All patients received an additional plastic stent implantation into the biliary tree following RFA. RESULTS: In the pig model, ablation time of 60-90 seconds using the bipolar soft coagulation mode at 8-10 watts with an effect of 8 was found to be the most feasible setting. Twelve patients(5 females, 7 males; mean age, 70 years) underwent 19 endoscopic RFA(range, 1-5) sessions. Deployment of RFA was successful in all patients. Systemic chemotherapy was administered in four patients. We observed biliary bleeding 4-6 wk after the intervention in three cases and two of these patients died: in one patient, spontaneous hemobilia occurred, whereas bleeding started during stent extraction in the other. In the third patient, bleeding was stopped by insertion of a non-covered self-expanding metal stent. Another three patients developed cholangitis during follow-up. Seven patients died during follow-up and median survival was 6.4 mo(95%CI: 0.05-12.7) from the time of the first RFA. CONCLUSION: Endoscopic RFA is an easy to perform and technically highly successful procedure. However, hemobilia possibly associated with RFA occurred in three of our patients. Therefore, larger prospective studies are needed to further evaluate the safety and efficacy of this promising new method.Andrea Oliver Tal Johannes Vermehren Mireen FriedrichRust Jrg Bojunga Christoph Sarrazin Stefan Zeuzem Jrg Trojan Jrg Gerhard Albert 2014World Journal of Gastrointestinal Endoscopy2014,6,1:18
2Transforming growth factor-β1 induces intestinal myofibroblast differentiation and modulates their migration显示文摘AIM:To investigate the effects of transforming growth factorβ1(TGF-β1)on the differentiation of colonic lamina propria fibroblasts(CLPF)into myofibroblasts in vitro. METHODS:Primary CLPF cultures were incubated with TGF-β1 and analyzed for production ofα-smooth muscle actin(α-SMA),fibronectin(FN)and FN isoforms.Migration assays were performed in a modified 48-well Boyden chamber.Levels of total and phosphorylated focal adhesion kinase(FAK)in CLPF were analyzed after induction of migration.RESULTS:Incubation of CLPF with TGF-β1 for 2 d did not changeα-SMA levels,while TGF-β1 treatment for 6 d significantly increasedα-SMA production. Short term incubation(6 h)with TGF-β1 enhanced CLPF migration,while long term treatment(6 d)of CLPF with TGF-β1 reduced migration to 15%-37% compared to untreated cells.FN and FN isoform mRNA expression were increased after short term incubation with TGF-β1(2 d)in contrast to long term incubation with TGF-β1 for 6 d.After induction of migration, TGF-β1-preincubated CLPF showed higher amounts of FN and its isoforms and lower levels of total and phosphorylated FAK than untreated cells. CONCLUSION:Long term incubation of CLPF with TGF-β1 induced differentiation into myofibroblasts with enhancedα-SMA,reduced migratory potential and FAK phosphorylation,and increased FN production.In contrast,short term contact(6 h)of fibroblasts with TGF-β1 induced a dose-dependent increase of cell migration and FAK phosphorylation without induction ofα-SMA production.Julia Brenmoehl Sandra Nicole Miller Claudia Hofmann Daniela Vogl Werner Falk Jrgen Schlmerich Gerhard Rogler 2009World Journal of Gastroenterology2009,15,12:12
3Exogenous sphingomyelinase causes impaired intestinal epithelial barrier function显示文摘AIM: To test the hypothesis that hydrolysis of sphingomyelin to ceramide changes the composition of tight junctions (TJs) with increasing permeability of the intestinal epithelium. METHODS: Monolayers of Caco-2 cells were used as an in vitro model for the intestinal barrier. Permeability was determined by quantifi cation of transepithelialflux and transepithelial resistance. Sphingolipid-rich membrane microdomains were isolated by a discontinuous sucrose gradient and characterized by Western-blot. Lipid content of microdomains was analysed by tandem mass spectrometry. Ceramide was subcellularly localized by immunofluorescent staining.RESULTS: Exogenous sphingomyelinase increased transepithelial permeability and decreased transepithelial resistance at concentrations as low as 0.01 U/mL. Lipid analysis showed rapid accumulation of ceramide in the membrane fractions containing occludin and claudin-4, representing TJs. In these fractions we observed a concomitant decrease of sphingomyelin and cholesterol with increasing concentrations of ceramide. Immunofluorescent staining confirmed clustering of ceramide at the sites of cell-cell contacts. Neutralization of surface ceramide prevented the permeability-increase induced by platelet activating factor. CONCLUSION: Our findings indicate that changes in lipid composition of TJs impair epithelial barrier functions. Generation of ceramide by sphingomyelinases might contribute to disturbed barrier function seen in diseases such as inflammatory, infectious, toxic or radiogenic bowel disease.Jürgen Bock Gerhard Liebisch Joachim Schweimer Gerd Schmitz Gerhard Rogler 2007World Journal of Gastroenterology2007,13,39:11
4Therapy-refractory gastrointestinal motility disorder in a child with c-kit mutations显示文摘Constipation and fecal impaction are frequent and distressing complaints in pediatric gastroenterology. Especially in neurologically handicapped children, treatment of severe forms of slow-transit constipation (STC) can be difficult. In the majority of cases, STC is of unknown etiology. However, in recent years, there is growing evidence that interstitial cells of Cajal (ICCs), which serve as electrical pacemakers and generate spontaneous electrical slow waves in the gastrointestinal tract, might play an important role in the pathophysiology of STC. It remains unclear whether morphological ICC alterations seen in affected patients are based on congenital developmental anomalies, or whether they are a consequence of long-term constipation with secondary damage of the gastrointestinal nervous system. To the best of our knowledge, we present the first case of a patient with histological alterations in ICC morphology who displayed multiple alterations of c-kit at the level of mRNA. The protein encoded by c-kit is the receptor tyrosine kinase Kit (CD117), which is crucial for development and function of ICCs. Therefore, these findings provide a new explanation for congenital alterations of ICC development that result in gastrointestinal motility disorders.Christian Breuer Jun Oh Gerhard J Molderings Michael Schemann Birgit Kuch Ertan Mayatepek Rüdiger Adam 2010World Journal of Gastroenterology2010,16,34:7
5SEMS vs cSEMS in duodenal and small bowel obstruction:High risk of migration in the covered stent group显示文摘AIM:To compare clinical success and complications of uncovered self-expanding metal stents(SEMS)vs covered SEMS(cSEMS)in obstruction of the small bowel.METHODS:Technical success,complications and outcome of endoscopic SEMS or cSEMS placement in tumor related obstruction of the duodenum or jejunum were retrospectively assessed.The primary end points were rates of stent migration and overgrowth.Secondary end points were the effect of concomitant biliary drainage on migration rate and overall survival.The data was analyzed according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines.RESULTS:Thirty-two SEMS were implanted in 20 patients.In all patients,endoscopic stent implantation was successful.Stent migration was observed in 9 of16 cSEMS(56%)in comparison to 0/16 SEMS(0%)implantations(P=0.002).Stent overgrowth did not significantly differ between the two stent types(SEMS:3/16,19%;cSEMS:2/16,13%).One cSEMS dislodged and had to be recovered from the jejunum by way of laparotomy.Time until migration between SEMS and cSEMS in patients with and without concomitant biliary stents did not significantly differ(HR=1.530,95%CI0.731-6.306;P=0.556).The mean follow-up was 57±71 d(range:1-275 d).CONCLUSION:SEMS and cSEMS placement is safe in small bowel tumor obstruction.However,cSEMS is accompanied with a high rate of migration in comparison to uncovered SEMS.Oliver Waidmann Jrg Trojan Mireen Friedrich-Rust Christoph Sarrazin Wolf Otto Bechstein Frank Ulrich Stefan Zeuzem Jrg Gerhard Albert 2013World Journal of Gastroenterology2013,19,37:4
6Second European evidence-based consensus on the diagnosis and management of ulcerative colitis: Special situations显示文摘Gert Van Assche Axel Dignass Bernd Bokemeyer Silvio Danese Paolo Gionchetti Gabriele Moser Laurent Beaugerie Fernando Gomollón Winfried H?user Klaus Herrlinger Bas Oldenburg Julian Panes Francisco Portela Gerhard Rogler Jürgen Stein Herbert Tilg Simon Tra 2012Journal of Crohn’s and Colitis2012,,:4
7A concise, practical guide to diagnostic assessment for mast cell activation disease显示文摘As recognition of mast cell(MC) involvement in a range of chronic inflammatory disorders has increased, diagnosticians' suspicions of MC activation disease(MCAD) in their chronically mysteriously inflamed patients have similarly increased. It is now understood that the various forms of systemic mastocytosis- diseases of inappropriate activation and proliferation of MCs seemingly driven by a small set of rare, usually constitutively activating mutations in assorted MC regulatory elements-comprise merely the tip of the MCAD iceberg, whereas the far larger and far more clinically heterogeneous(and thus more difficult to recognize) bulk of the iceberg consists of assorted forms of MC activation syndrome(MCAS) which manifest little to no abnormal MC proliferation and may originate from a far more heterogeneous set of MC mutations. It is reasonable to suspect MCAD when symptoms and signs of MC activation are present and no other diagnosis better accounting for the full range of findings is present. Initial laboratory assessment should include not only routine blood counts and serum chemistries but also a serum total tryptase level, which helps direct further evaluation for mastocytosis vs MCAS. Appropriate tissue examinations are needed to diagnose mastocytosis, while elevated levels of relatively specific mast cell mediators are sought to support diagnosis of MCAS. Whether assessing for mastocytosis or MCAS, testing is fraught with potential pitfalls which can easily yield false negatives leading to erroneous rejection of diagnostic consideration of MCAD in spite of a clinical history highly consistent with MCAD. Efforts at accurate diagnosis of MCAD are worthwhile, as many patients then respond well to appropriately directed therapeutic efforts.Lawrence B Afrin Gerhard J Molderings 2014World Journal of Hematology2014,3,1:3
8Coxsackievirus mutants that can bypass host factor PI4KIIIβ and the need for high levels of PI4P lipids for replication显示文摘Hilde M van der Schaar Lonneke van der Linden Kjerstin H W Lanke Jeroen R P M Strating Gerhard Purstinger Erik de Vries Cornelis A M de Haan Johan Neyts Frank J M van Kuppeveld 2012Cell Research2012,22,11:3
9Design and discovery of materials guided by theory and computation显示文摘Computational materials science and engineering has emerged as an interdisciplinary subfield spanning materials science and engineering,condensed matter physics,chemistry,mechanics and engineering in general.Modern materials research often requires a close integration of computation and experiments in order to fundamentally understand the materials structures and properties and their relation to synthesis and processing.A number of computational methods and tools at different spatiotemporal scales are now well established,ranging from electronic structure calculations based on density functional theory,1,2 atomic molecular dynamics3,4 and Monte Carlo techniques,5 phase-field method6–9 to continuum macroscopic approaches.Over the last few years,computational materials activities have been steadily moving from technique development and purely computational studies of materials towards discovering and designing new materials guided by computation,machine learning and data mining or by a closely tied combination of computational predictions and experimental validation.This movement is being further accelerated by the recent initiatives by various government agencies in the United States,Europe,China and other countries to pursue the materials genome initiative,10 integrated computational materials engineering11–13 as well as the‘Big Data’initiative.Long-Qing Chen Li-Dong Chen Sergei V Kalinin Gerhard Klimeck Sanat K Kumar Jörg Neugebauer Ichiro Terasaki 2015npj Computational Materials2015,,1:2
10The induction of ovulation with pulsatile GnRH administration in hyperandrogenic woman after down -regulation with buserelin or suppression with a oral contraceptive 显示文摘Gerhard I Matthes J Runncbaum B 1993HumReprod1993,8,:1
11Approximation algorithms for scheduling malleable tasks under precedence constraints显示文摘RENAUD L DENIS T GERHARD J W 2002International Journal of Foundations of Computer Science2002,13,4:1
12Decomposition of nitrous oxide at medium temperatures显示文摘Loffler Gerhard Wargadalam Verina J Winter Franz 2000Combustion and Flame2000,120,4:1
13Value of the prednisolone test in my opathydiagnosis显示文摘Jorg J Gerhard H 1984Fortschr NeurolPsychiatar1984,52,:1
14显示文摘 Helen L Gerhard J 1998Chest1998,114,:1
15Value of the prednisolonetestin myopathy diagnosis显示文摘Jorg J Gerhard H 1984Forrschr Neurol Psychiatar1984,52,1:1
16Pressure calculation in polar and charged systems using Ewald summation: results for the extended simple point charge model water显示文摘GERHARD H NIELS G J 1998Journal of Chemical Physics1998,109,7:1
17Air-water gas transfer in uniform channel flow显示文摘Douglas B M Gerhard H J 1999Journal of hydraulic engineering1999,125,1:1
18The incidence of inflammatory bowel disease in a rural region of Southern Germany: a prospective population-based study显示文摘Claudia Ott Florian Obermeier Sabine Thieler Daniela Kemptner Alexandra Bauer Jürgen Sch?lmerich Gerhard Rogler Antje Timmer 2008European Journal of Gastroenterology & Hepatology2008,,9:1
19Genetic variation of CYP2A6, smoking, and risk of cancer显示文摘Stephanie J London Jeffrey R Idle Ann K Daly Gerhard A Coetzee 19991999 (9156)1999,,9156:1
20New self-assembled structural motifs in coordination chemistry显示文摘 Tshepo J Malefetes 2000Chem Rev2000,100,:1
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