title: [The expression of Ras protein in human middle ear cholesteatoma].
abstract: OBJECTIVE
  To evaluate the possible role of Ras protein in acquired middle ear cholesteatoma.
  
  
  METHODS
  The specimens from the acquired middle ear cholesteatoma tissue of 22 cases and the normal external ear skin of 10 cases were examined by immunohistochemical S-P method and computer image analysis.
  
  
  RESULTS
  All epithelial layers of cholesteatoma revealed a relatively abundant expression of Ras protein, among which 15 cases showed an inner plasma membrane expression, 5 cases a cytoplasm and membrane expression, and 2 cases cytoplasm expression only. In contrast, the normal external ear skin revealed a sparse distribution of Ras protein in the inner plasma membrane of epithelial cells with a more intensely staining in the basal layer. The integral absorbency of Ras protein in the two types of tissues were 0.870 and 0.463 respectively with a significant difference between them.
  
  
  CONCLUSIONS
  There is an aberrant regulation of Ras protein in cholesteatoma. Ras protein plays a pivotal role during the aberrant growth and the differentiation of cholesteatoma.
authors.affiliation: Department of Otorhinolaryngology, Second Affiliated Hospital of Hubei Medical University, Wuhan 430071.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: K
authors.initials: K
authors.lastname: Jin
authors.forename: W
authors.initials: W
authors.lastname: Dong
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018631:ras Proteins / Q000096:biosynthesis*
chemical_list: D018631:ras Proteins