title: Bcl-2 and Bax expressions in pre-term, term and post-term placentas.
abstract: OBJECTIVE
  Placental apoptosis-associated protein imbalance might contribute to the pathogenesis of pre- and post-term birth. Therefore, we evaluated the expression and distribution of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) molecules in term, pre-term and post-term placentas.
  
  
  METHODS
  Placental samples were collected from women with term (n = 25), pre-term (n = 7) and post-term (n = 10) deliveries. The expression of Bcl-2 and Bax was assessed by immunochemistry on paraffin-embedded placental specimens.
  
  
  RESULTS
  The pattern of immunostaining for Bcl-2 and Bax was the same in all samples, but not the intensity. The Bax/Bcl-2 ratio was higher in both pre-term and post-term placental samples compared with term placentas as a result of intense reactivity for the pro-apoptotic factor, Bax in pre-term and post-term placentas and, for Bcl-2 decrease in pre-term placentas.
  
  
  CONCLUSIONS
  These findings suggest that different unbalance mechanisms in placental apoptotic-associated protein expressions may be involved in the physiopathology of pre-term and post-term births.
authors.affiliation: Department of Obstetrics, Paulista Medical School, São Paulo Federal University, São Paulo, Brazil. silviadaher@hotmail.com
authors.forename: Silvia
authors.initials: S
authors.lastname: Daher
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Guimarães
authors.forename: Rosiane
authors.initials: R
authors.lastname: Mattar
authors.forename: Márcia M S
authors.initials: MM
authors.lastname: Ishigai
authors.forename: Erica G
authors.initials: EG
authors.lastname: Barreiro
authors.forename: Estela
authors.initials: E
authors.lastname: Bevilacqua
mesh_terms: D017209:Apoptosis; D005260:Female; D015870:Gene Expression; D006801:Humans; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D047928:Premature Birth / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D047929:Term Birth / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: C494826:BAX protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein