title: Increased Oxidative Stress in the Proximal Stomach of Patients with Barrett's Esophagus and Adenocarcinoma of the Esophagus and Esophagogastric Junction.
abstract: OBJECTIVE
  Oxidative stress (OS) is an essential element in the pathogenesis of Barrett's esophagus (BE) and its transformation to adenocarcinoma (EAC). The state of OS in the proximal stomach of patients with BE and EAC is unknown. Isoprostanes are a specific marker of OS not previously used to determine OS from BE/EAC tissue samples.
  
  
  METHODS
  OS was measured in 42 patients with BE (n = 9), EAC (n = 9), or both (n = 24) and 15 control patients. A STAT-8-Isoprostane EIA Kit served to identify 8-Isoprostanes (8-IP), and a Glutathione Assay Kit was used to measure glutathione reduced form (GSH) and glutathione oxidized form. An OxiSelect Oxidative DNA Damage ELISA Kit (8-OHdG) served to measure 8-OH-deoxyguanosine.
  
  
  RESULTS
  The 8-IP (P = .039) and 8-OHdG (P = .008) levels were higher, and the GSH level lower (P = .031), in the proximal stomach of the study group than in that of the controls. Helicobacter pylori infection was present in 8% of the study patients.
  
  
  CONCLUSIONS
  In the proximal stomach of BE and EAC patients, OS was elevated and antioxidative capacity was reduced. This finding suggests that the gastroesophageal reflux causing BE also induces oxidative stress in the proximal stomach and may contribute to the development of cancer in the proximal stomach and gastric cardia.
authors: Helsinki University, Helsinki University Hospital, Heart and Lung Center, Department of General Thoracic and Esophageal Surgery, 00290, Helsinki, Finland.
authors: Juha
authors: J
authors: Kauppi
authors: Helsinki University, Helsinki University Hospital, Heart and Lung Center, Department of General Thoracic and Esophageal Surgery, 00290, Helsinki, Finland.
authors: Jari
authors: J
authors: Räsänen
authors: Helsinki University, Helsinki University Hospital, Heart and Lung Center, Department of General Thoracic and Esophageal Surgery, 00290, Helsinki, Finland.
authors: Eero
authors: E
authors: Sihvo
authors: Helsinki University, Helsinki University Hospital, Department of Gastroenterology, 00290, Helsinki, Finland.
authors: Urpo
authors: U
authors: Nieminen
authors: Helsinki University, Helsinki University Hospital, Department of Gastroenterology, 00290, Helsinki, Finland.
authors: Perttu
authors: P
authors: Arkkila
authors: Turku University, Department of Biosciences, 20520, Turku, Finland.
authors: Markku
authors: M
authors: Ahotupa
authors: Helsinki University, Helsinki University Hospital, Heart and Lung Center, Department of General Thoracic and Esophageal Surgery, 00290, Helsinki, Finland. Electronic address: jarmo.salo@hus.fi.
authors: Jarmo
authors: J
authors: Salo