title: Gerbilline cholesteatoma development Part III. Increased proliferation index of basal keratinocytes of the tympanic membrane and external ear canal.
abstract: OBJECTIVE
  To quantify the rate of basal cell division for keratinizing epithelium (KE) of the tympanic membrane (TM) and external ear canal (EAC) in spontaneous and induced gerbilline cholesteatomas.
  
  
  METHODS
  Cholesteatomas (3 spontaneous and 5 by induction) were labeled with tritiated thymidine for autoradiography and a KE proliferation index (PI) was determined. The PI was defined as the average number of labeled cells/mm overall and per anatomic region.
  
  
  RESULTS
  For all regions combined, the PI was 27.3 in ears with cholesteatoma and 4.1 in normal ears (P < 0.0001). Additionally, there were significant regional differences in the PI in both normal ears and ears with cholesteatoma.
  
  
  CONCLUSIONS
  The KE of cholesteatomas in gerbils proliferates at approximately 7 times the rate measured in control ears.
  
  
  CONCLUSIONS
  Hyperproliferation of keratinocytes is a causative factor in the development and progression of spontaneous and experimental cholesteatomas in gerbils.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of California-Davis, Otolaryngology Research Laboratory, 1515 Newton Court, Davis, CA 95616, USA. sptinling@ucdavis.edu
authors.forename: Steven P
authors.initials: SP
authors.lastname: Tinling
authors.forename: Richard A
authors.initials: RA
authors.lastname: Chole
mesh_terms: D000818:Animals; D001345:Autoradiography; D049109:Cell Proliferation; D002781:Cholesteatoma / Q000473:pathology* / Q000662:veterinary; D004195:Disease Models, Animal; D018450:Disease Progression; D004424:Ear Canal / Q000473:pathology*; D004427:Ear Diseases / Q000473:pathology* / Q000662:veterinary; D005500:Follow-Up Studies; D005849:Gerbillinae; D015603:Keratinocytes / Q000473:pathology*; D008297:Male; D051381:Rats; D014432:Tympanic Membrane / Q000473:pathology*