title: Chemotherapy for cancer causes apoptosis that precedes hypoplasia in crypts of the small intestine in humans.
abstract: OBJECTIVE
  The mechanism of gastrointestinal damage (mucositis) induced by cancer chemotherapy remains uncertain. The aims of this study were to define the time course and mechanism of small intestinal damage following chemotherapy in humans.
  
  
  METHODS
  Patients receiving chemotherapy underwent upper gastrointestinal endoscopy (a maximum of two per patient) with duodenal biopsy prior to chemotherapy and again at 1, 3, 5, and 16 days after chemotherapy. Tissue was taken for morphometry, disaccharidase assays, electron microscopy, and for assessment of apoptosis using the Tdt mediated dUTP-biotin nick end labelling (TUNEL) method. Villus area, crypt length, and mitotic index were measured by a microdissection technique.
  
  
  RESULTS
  Apoptosis increased sevenfold in intestinal crypts at one day, and villus area, crypt length, mitotic count per crypt, and enterocyte height decreased at three days after chemotherapy. Disaccharidase activities remained unchanged. Electron microscopy showed increased open tight junctions of enterocytes at day 3, consistent with more immature cells. All indices improved by 16 days.
  
  
  CONCLUSIONS
  Small intestinal mucositis is associated with apoptosis in crypts that precedes hypoplastic villous atrophy and loss of enterocyte height.
authors.affiliation: Department of Gastroenterology, Queen Elizabeth Hospital, Woodville South, South Australia 5011, Australia. dkeefe@mail.rah.sa.gov.au
authors.forename: D M
authors.initials: DM
authors.lastname: Keefe
authors.forename: J
authors.initials: J
authors.lastname: Brealey
authors.forename: G J
authors.initials: GJ
authors.lastname: Goland
authors.forename: A G
authors.initials: AG
authors.lastname: Cummins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D017209:Apoptosis / Q000187:drug effects*; D001706:Biopsy; D004186:Disaccharidases / Q000032:analysis; D004386:Duodenum / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D016099:Endoscopy, Gastrointestinal; D004751:Enteritis / Q000139:chemically induced* / Q000503:physiopathology / Q000601:surgery; D020895:Enterocytes / Q000473:pathology; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D008940:Mitotic Index; D012075:Remission, Spontaneous; D019108:Tight Junctions / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D004186:Disaccharidases