title: Influence of urease activity in the intestinal tract on the results of 13C-urea breath test.
abstract: OBJECTIVE
  A late rise in (13)CO2 excretion in the (13)C-urea breath test (UBT) should be found when the substrate passes rapidly through the stomach and makes contact with the colonic bacteria. The aim of this study was to evaluate the influence of intestinal urease activity on the results of the UBT.
  
  
  METHODS
  A total of 143 subjects who were diagnosed as Helicobacter pylori negative by serology, histology and rapid urease test were recruited. At the end of endoscopy, the tip of the endoscope was placed to the second part of the duodenum and 20 mL of water containing 100 mg of (13)C-urea was sprayed into the duodenum. Breath samples were taken at baseline and at 5, 10, 20, 30 and 60 min after administration.
  
  
  RESULTS
  Of 143 subjects, breath Delta(13)CO2 values higher than 2.5 per thousand were detected in six (4.2%), four (2.8%) and five (3.5%) subjects at 20, 30 and 60 min, respectively. There was no subject with high Delta(13)CO2 values at 5 and 10 min. Only one subject had an immediate rise at 60 min.
  
  
  CONCLUSIONS
  Variability derived from urease activity in the intestinal tract appears to be minimal up to 60 min after ingestion of the test urea.
authors: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Faculty of Medicine, Toho University School of Medicine, Tokyo, Japan. foo@eb.mbn.or.jp
authors: Yoshihisa
authors: Y
authors: Urita
authors: Kazuo
authors: K
authors: Hike
authors: Naotaka
authors: N
authors: Torii
authors: Yoshinori
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authors: Kikuchi
authors: Eiko
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authors: Kanda
authors: Hidenori
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authors: Kurakata
authors: Masahiko
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authors: Sasajima
authors: Kazumasa
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authors: Miki