title: Oxidative stress in gastric mucosa of asymptomatic humans infected with Helicobacter pylori: effect of bacterial eradication.
abstract: BACKGROUND
  Inducible nitric oxide synthase (iNOS) and interleukin 8 (IL-8) are positive in approximately 50% of Helicobacter pylori-related diseases but it is not clear whether oxidative stress is also present in H. pylori asymptomatic humans. Our aim was to study the expression of iNOS, superoxide dismutase, catalase and IL-8 production in H. pylori-infected asymptomatic humans, and to investigate the effect of eradication of H. pylori.
  
  
  METHODS
  Biopsies of corpus and antrum of asymptomatic H. pylori positive and negative humans served for determination of the gastritis score and H. pylori status; iNOS was measured by reverse transcriptase polymerase chain reaction and immunohistochemistry and superoxide dismutase and catalase by immunohistochemistry. IL-8 in biopsies was assessed by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Immunostaining of iNOS, catalase and superoxide dismutase was significantly associated with H. pylori infection and was localized to inflammatory cells. IL-8 concentrations were greater in the H. pylori positive than H. pylori negative group and decreased after bacterial eradication. A decrease in staining for iNOS and catalase was observed after H. pylori eradication.
  
  
  CONCLUSIONS
  INOS and antioxidant enzymes are present in gastric biopsies of asymptomatic H. pylori positive humans. Eradication caused a significant decrease in staining for iNOS and catalase. These results indicate that oxidative stress occurs in asymptomatic patients and can be modulated by H. pylori eradication.
authors.affiliation: Division of Gastroenterology, University Hospital, University of Lausanne, Lausanne, Switzerland.
authors.forename: C P
authors.initials: CP
authors.lastname: Felley
authors.forename: B
authors.initials: B
authors.lastname: Pignatelli
authors.forename: G D
authors.initials: GD
authors.lastname: Van Melle
authors.forename: J E
authors.initials: JE
authors.lastname: Crabtree
authors.forename: M
authors.initials: M
authors.lastname: Stolte
authors.forename: J
authors.initials: J
authors.lastname: Diezi
authors.forename: I
authors.initials: I
authors.lastname: Corthesy-Theulaz
authors.forename: P
authors.initials: P
authors.lastname: Michetti
authors.forename: B
authors.initials: B
authors.lastname: Bancel
authors.forename: L M
authors.initials: LM
authors.lastname: Patricot
authors.forename: H
authors.initials: H
authors.lastname: Ohshima
authors.forename: E
authors.initials: E
authors.lastname: Felley-Bosco
mesh_terms: D000328:Adult; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D015415:Biomarkers; D001706:Biopsy; D002374:Catalase / Q000378:metabolism; D017291:Clarithromycin / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology* / Q000382:microbiology*; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009853:Omeprazole / Q000627:therapeutic use; D018384:Oxidative Stress / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D015415:Biomarkers; D016209:Interleukin-8; D000658:Amoxicillin; D002374:Catalase; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase; D017291:Clarithromycin; D009853:Omeprazole