title: Apoptosis in epithelial cells of apical radicular cysts.
abstract: OBJECTIVE
  To investigate the occurrence of apoptotic cell death in the epithelium of radicular cysts and to compare its frequency in lesions presenting a distinct functional state.
  
  
  METHODS
  Twenty radicular cysts were selected and arranged into two groups with 10 lesions in each group: atrophic (quiescent) and hyperplastic (active) epithelium. Morphologic investigations of apoptosis were conducted by means of optic microscopy in haematoxylin and eosin slides. Immunohistochemical techniques to detect the bcl-2 protein were carried out by streptavidin-biotin-peroxidase assay. In both instances, 30 sequential high-power microscopic fields were observed to determine apoptotic (AI) and bcl-2 immunostaining (bcl-2I) indexes. The presence of AI and bcl-2I within the two groups was compared using the t-test. Correlation between the AI and the bcl-2I was investigated using the Spearman test.
  
  
  RESULTS
  Apoptosis was detected in the epithelium of all cysts. Higher AI levels were found in lesions with an atrophic (0.17 +/- 0.19) rather than a hyperplastic (0.10 +/- 0.10) epithelium. The same was found for the bcl-2I levels (0.06 +/- 0.03 vs. 0.04 +/- 0.01, respectively). However, these differences were not statistically significant. A positive and significant correlation was found between AI and bcl-2I.
  
  
  CONCLUSIONS
  Apoptosis was always present in the epithelium of the lesions and was more frequent in lesions with atrophic (quiescent) epithelium.
authors.affiliation: Oral Pathology Laboratory, School of Dentistry, Federal University of Uberlândia, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Loyola
authors.forename: S V
authors.initials: SV
authors.lastname: Cardoso
authors.forename: G S
authors.initials: GS
authors.lastname: Lisa
authors.forename: L J
authors.initials: LJ
authors.lastname: Oliveira
authors.forename: R A
authors.initials: RA
authors.lastname: Mesquita
authors.forename: M A V
authors.initials: MA
authors.lastname: Carmo
authors.forename: M C F
authors.initials: MC
authors.lastname: Aguiar
mesh_terms: D017209:Apoptosis; D004847:Epithelial Cells / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D011842:Radicular Cyst / Q000473:pathology*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2