title: A novel endoscopic marker: safety experiments in the rat stomach.
abstract: OBJECTIVE
  The study aimed to assess a newly developed endoscopic marker designed to cause only minor inflammatory reactions.
  
  
  METHODS
  Chitosan and carbon powder were used in the marker substance. The product was a viscoelastic solution, which was injected into the submucosa in rat stomach walls. The tissue reactions were then examined histopathologically. The structure of the injected marker substance was examined with electron microscopy into rat stomach walls. India ink, which is currently used as an endoscopic marker, served as the control.
  
  
  RESULTS
  Histopathological examination showed that inflammatory reactions with the novel agent were remarkably mild in the rat organs, while submucosally applied india ink caused severe inflammation in situ. The electron-microscopic findings showed that the carbon particles used were completely spherical in shape and that the carbon in the marker substance was entrapped in the chitosan networks. The india ink was shown to consist of a mixture of fine carbon particles and adhesive additives.
  
  
  CONCLUSIONS
  The chitosan-carbon solution appears to be a promising endoscopic marker substance, causing significantly reduced inflammation.
authors: Department of Surgery I, Iwate Medical University, Morioka, Japan. akiosugi@iwate-med.ac.jp
authors: A
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authors: Sugitachi
authors: K
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authors: Otsuka
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authors: Akiyama
authors: T
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authors: Itabashi
authors: H
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authors: Asahi
authors: N
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authors: Uesugi
authors: R
authors: R
authors: Tsutsumi
authors: K
authors: K
authors: Saito