Abstract:
BACKGROUND:Survival of Helicobacter pylori is dependent upon urease in the cytoplasm and at the bacterial surface. We have sought to clarify how alkaline ammonium salts, released from urea by this enzyme, might alter mucus pH and so affect growth and motility of the bacterium in the gastric mucus environment. METHODS:Experiments were conducted in vitro to determine how the growth and motility of H. pylori are affected by changes in external pH, and how the bacterium, by hydrolysing urea, alters the pH of the bicarbonate buffer that occurs at the gastric mucosal surface. These data were fitted into experimental models that describe how pH varies within the mucus layer in the acid-secreting stomach. RESULTS:H. pylori was motile between pH 5 and 8, with optimal motility at pH 5. It grew between pH 6 and 8, with optimal growth at pH 6. The bacterium had urease activity between pH 2.7 and 7.4, as evidenced by pH rises in bicarbonate-buffered solutions of urea. Changes in buffer pH were dependent upon initial pH and urea concentration, with the greatest rate of pH change occurring at pH 3. Modelling experiments utilizing these data indicated that (1) in the absence of urease, H. pylori growth and motility in the mucus layer would be restricted severely by low mucus pH in the acid-secreting stomach, and (2) urease will sometimes inhibit H. pylori growth and motility in the mucus layer by elevating the pH of the mucus environment above pH 8. CONCLUSIONS:Urease is essential to the growth and motility of H. pylori in the mucus layer in the acid-secreting stomach, but, paradoxically, sometimes it might suppress colonization by raising the mucus pH above 8. This latter effect may protect the bacteria from the adverse consequences of overpopulation.
journal_name
Eur J Gastroenterol Hepatoljournal_title
European journal of gastroenterology & hepatologyauthors
Sidebotham RL,Worku ML,Karim QN,Dhir NK,Baron JHdoi
10.1097/00042737-200304000-00010subject
Has Abstractpub_date
2003-04-01 00:00:00pages
395-401issue
4eissn
0954-691Xissn
1473-5687journal_volume
15pub_type
杂志文章abstract:PURPOSE:To evaluate the efficacy and safety of ambulatory seton placement followed by superficial fistulotomy as treatment of perianal fistula. METHODS:Retrospective observational analysis of patients with cryptogenic perianal fistula aged 18-90 years, followed in a central hospital proctology consultation between 200...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000001913
更新日期:2020-09-09 00:00:00
abstract:OBJECTIVE:The aim of this study was to establish a clinical scoring formula of liver injury (SFLI) using the matter element analysis method, in order to provide the necessary information for the preoperative assessment and treatment of liver cirrhosis in clinical practice. MATERIALS AND METHODS:We collected preoperati...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e3283632189
更新日期:2014-01-01 00:00:00
abstract:BACKGROUND AND AIM:A significant proportion of patients presenting with obscure gastrointestinal bleeding (OGIB) have negative small bowel capsule endoscopy (SBCE) examinations, and yet remain at risk of rebleeding. We aimed to evaluate whether a second-look review of SBCE images using flexible spectral color enhanceme...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000000358
更新日期:2015-06-01 00:00:00
abstract:OBJECTIVE:To modulate experimental colitis by the direct intramuscular injection of cDNA expression vector encoding transforming growth factor-beta 1. METHODS:Colitis was induced in rats by the intracolonic administration of 0.25 ml 50% ethanol containing 30 mg trinitrobenzene sulfonic acid. Three and 10 days later th...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:
更新日期:1995-04-01 00:00:00
abstract:BACKGROUND AND AIM:Pancreatitis and hyperamylasaemia are common complications of ERCP and this study was designed to explain which operative and patient factors predispose to them. PATIENTS AND METHODS:A 1 year prospective study of consecutive patients in a single operator centre with detailed attention to technical f...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/00042737-199805000-00012
更新日期:1998-05-01 00:00:00
abstract:OBJECTIVES:Analysis of the incidence rate and the evolution of duodenal and stomach polyps in our familial adenomatous polyposis (FAP) patients, the suitability of the surveillance method and the cancer-preventing treatment applied and the analysis of the complications arising from each procedure employed. MATERIALS A...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e3283297cf2
更新日期:2009-10-01 00:00:00
abstract:OBJECTIVES:Hepatitis A virus (HAV) infection tends to be a self-limiting disease without serious sequelae, but fulminant hepatitis, with a high mortality, develops in 0.1-0.2% of the cases. Sometimes, HAV infection precipitates autoimmune hepatitis (AIH). We aimed to assess the frequency and clinical significance of se...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000000413
更新日期:2015-10-01 00:00:00
abstract:OBJECTIVE:To compare zaldaride maleate, a calmodulin inhibitor with gastrointestinal antisecretory properties, with loperamide and a placebo in the treatment of travellers' diarrhoea. DESIGN:Randomized, double-blind, double-dummy study. SETTING:Study clinic staffed by European residents on Nile cruise ships. PATIENT...
journal_title:European journal of gastroenterology & hepatology
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1995-09-01 00:00:00
abstract:OBJECTIVE:The development of gallstones is influenced by obesity and alcohol. This study aimed to precisely quantify these risks and investigate whether the aetiological mechanism may involve serum lipids, for the first time using a European prospective cohort study. METHODS:The European Prospective Investigation into...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章,多中心研究
doi:10.1097/MEG.0b013e3283477cc9
更新日期:2011-08-01 00:00:00
abstract::Strong evidence is presented in this randomized, prospective study that biliary stenting alone is as effective as biliary stenting with sphincterotomy in the treatment of uncomplicated post-laparoscopic cholecystectomy bile leaks. ...
journal_title:European journal of gastroenterology & hepatology
pub_type: 评论,杂志文章,评审
doi:10.1097/01.meg.0000231751.50587.75
更新日期:2006-10-01 00:00:00
abstract:BACKGROUND:Screening colonoscopy is less effective in preventing proximal colon cancers than distal colon cancers. A repeat examination of the right side of the colon may increase the lesion detection. The study aimed to assess the results of a second examination of the right side of the colon with forward-view or retr...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章,meta分析,评审
doi:10.1097/MEG.0000000000001009
更新日期:2018-02-01 00:00:00
abstract:AIM:Intrahepatic cholestasis of pregnancy (ICP) is associated with safe maternal outcomes but perinatal outcomes have been variable. We assessed clinical factors and impact of bile acid levels on maternal and neonatal outcomes in ICP. METHODS:Patients with ICP (defined as pruritus with serum bile acids ≥ 10 mmol/l) we...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000001954
更新日期:2020-10-29 00:00:00
abstract::Encephalopathy is a significant complication of transjugular intrahepatic portosystemic stent-shunt (TIPSS). The majority respond to medical treatment but a proportion prove recalcitrant to conservative measures and eventually require some modulation of shunt blood flow in order to ameliorate their symptoms. This is p...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/00042737-200412000-00025
更新日期:2004-11-01 00:00:00
abstract::Amyloidosis is a group of disorders that can manifest in virtually any organ system in the body and is thought to be secondary to misfolding of extracellular proteins with subsequent deposition in tissues. The precursor protein that is produced in excess defines the specific amyloid type. This requires histopathologic...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章,评审
doi:10.1097/MEG.0000000000000695
更新日期:2016-10-01 00:00:00
abstract:BACKGROUND AND AIM:The accurate detection of synchronous neoplasia is important to reduce the risk of recurrence after endoscopic resection. Trimodal imaging endoscopy (TMIE) was developed for this purpose. Our aim was to compare the effects of TMIE and white-light imaging endoscopy (WLIE) in gastric neoplasia detectio...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000000278
更新日期:2015-03-01 00:00:00
abstract:OBJECTIVES:The diagnostic and prognostic value of critical flicker frequency (CFF) analysis for assessment of severity and dynamics of hepatic encephalopathy (HE) was studied before and after implantation of a transjugular intrahepatic portosystemic shunt (TIPS). BASIC METHODS:Sixty-three cirrhotic patients were retro...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e328310e0c3
更新日期:2009-12-01 00:00:00
abstract:OBJECTIVE:There has been a dramatic increase in recent years in the incidence of Barrett's oesophagus and the oesophageal adenocarcinoma associated with it. Alongside surgical treatment for early Barrett's carcinomas, endoscopic treatment procedures such as photodynamic therapy (PDT), which have much lower complication...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/00042737-200206000-00011
更新日期:2002-06-01 00:00:00
abstract:OBJECTIVES:The activation of hepatic stellate cells (HSC) is considered the most important event in hepatic fibrogenesis. The precise mechanism of this process is unknown in autoimmune hepatitis (AIH), and more evidence is needed on the evolution of fibrosis. The aim of this study was to assess these aspects in childre...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e328326cab6
更新日期:2010-03-01 00:00:00
abstract:BACKGROUND:One study has suggested that markers of acute hepatitis E virus (HEV) infection are present in 3.6% of patients with severe alcoholic hepatitis (AH). However, validation of these preliminary results is lacking, as well as the impact of HEV infection on the 6-month survival. AIMS:The aims of this study were ...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000000459
更新日期:2015-12-01 00:00:00
abstract::Antiphospholipid antibodies are a heterogeneous group of acquired autoantibodies that react with anionic phospholipids, such as cardiolipin. Anticardiolipin antibodies (ACAs) are frequently found in patients with systemic lupus erythematosus and other autoimmune disorders and can react with the phospholipid alone or b...
journal_title:European journal of gastroenterology & hepatology
pub_type: 评论,杂志文章
doi:10.1097/01.meg.0000059144.68845.61
更新日期:2003-07-01 00:00:00
abstract:BACKGROUND AND STUDY AIMS:Although endoscopic papillary balloon dilation (EPBD) has appeared with the expectation of better preserving sphincter of Oddi function than endoscopic sphincterotomy (EST), whether it can more effectively prevent bacterial contamination of the biliary tract than EST is controversial. To addre...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e328348c0bf
更新日期:2011-09-01 00:00:00
abstract:OBJECTIVE:To investigate a possible dose-effect relationship with two dosages of oral slow-release mesalazine in patients with quiescent ulcerative colitis. METHOD:One hundred and sixty-nine patients with ulcerative colitis in remission were treated with either 1.5 or 3.0 g/day mesalazine for 1 year or until relapse i...
journal_title:European journal of gastroenterology & hepatology
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1097/00042737-199511000-00003
更新日期:1995-11-01 00:00:00
abstract::A 46-year-old woman was admitted to our department with symptoms of nausea, anorexia and asthenia. Serum alanine aminotransferase and aspartate aminotransferase levels were increased; all serological tests for viral hepatitis and autoimmune disorders were negative. She had taken Lycopodium similiaplex solution as seda...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e3282f1623d
更新日期:2008-05-01 00:00:00
abstract::Ulcerative colitis (UC) is an inflammatory disease of the colon. Involvement of the small bowel is limited to backwash ileitis or pouch-related conditions. Here, we report two men with UC who presented with small bowel inflammation and even perforation, within 1 month after subtotal colectomy. Endoscopy showed diffuse...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章,评审
doi:10.1097/MEG.0b013e32831bc400
更新日期:2009-06-01 00:00:00
abstract:BACKGROUND:Patients with achalasia require repeated invasive therapies and may experience multiple complications. The objectives of this study were to determine the incidence of such complications, causes of death, and life expectancy in 253 patients. METHODS:Patients consisted of two groups: group A comprised 177 pat...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e3282fbf5e5
更新日期:2008-10-01 00:00:00
abstract:OBJECTIVE:To assess the accuracy of the determination of Helicobacter pylori infection by a stool immunoassay in patients with upper-gastrointestinal bleeding (UGB) of peptic origin, in comparison with the routine histological study, serology, rapid urease and 13C-breath tests. METHODS:Sixty-eight patients with endosc...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/01.meg.0000059114.41030.a9
更新日期:2003-05-01 00:00:00
abstract:OBJECTIVE:The objective of this analysis was to identify predictors of relapse in genotype 1 patients after 48 weeks of treatment with peginterferon plus ribavirin. METHODS:Retrospective analysis of data from treatment-naive genotype 1 patients with an end-of-treatment response after 48 weeks of treatment with peginte...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0b013e32832d237d
更新日期:2010-05-01 00:00:00
abstract:OBJECTIVES:Liver transplant recipients are often screened for spontaneous bacterial peritonitis during the immediate preoperative evaluation to determine medical fitness to proceed. However, it is unknown whether subclinical spontaneous bacterial peritonitis impacts on post-transplant outcomes. Our aim was to determine...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/MEG.0000000000000473
更新日期:2016-01-01 00:00:00
abstract:OBJECTIVE:Radiolucent pancreatic lithiasis (RPL) has been identified as a different entity from calcified pancreatic lithiasis. The purpose of this study is to evaluate the frequency, characteristics and evolution of RPL. PATIENTS:Between 1983 and 1995, 278 consecutive patients who presented with pancreatic lithiasis ...
journal_title:European journal of gastroenterology & hepatology
pub_type: 杂志文章
doi:10.1097/00042737-199707000-00010
更新日期:1997-07-01 00:00:00
abstract:AIM:To compare the effect of pantoprazole and esomeprazole on intra-oesophageal pH and investigate their pharmacokinetics in patients with symptomatic gastro-oesophageal reflux disease (GORD). METHODS:Double-blind, randomized, two-period crossover study. Caucasian men with symptomatic GORD (n=48) were selected on the ...
journal_title:European journal of gastroenterology & hepatology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/01.meg.0000059157.46867.42
更新日期:2003-07-01 00:00:00