title: Why does the fallopian tube fail in ectopic pregnancy? The role of activins, inducible nitric oxide synthase, and MUC1 in ectopic implantation.
abstract: OBJECTIVE
  To investigate the role of activin-βA subunit, activin type II receptors, inducible nitric oxide synthase (iNOS), and MUC1 in the pathogenesis of ectopic pregnancy (EP) and their involvement in the determination of the implantation site.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Academic unit of reproductive and developmental medicine.
  
  
  METHODS
  Four women at the luteal phase, three pseudopregnant women at the time of hysterectomy for benign disease, and 10 archived cases of EP. We collected 14 Fallopian tubes were collected from four women at the luteal phase and three pseudopregnant women at the time of hysterectomy for benign disease; specimens from implantation site, trophoblast and remote sites from the implantation site were collected from 10 archived cases of EP.
  
  
  METHODS
  Immunohistochemistry and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR).
  
  
  METHODS
  Comparison of the expression of candidate molecules between the different groups.
  
  
  RESULTS
  The expression of activin-βA subunit, activin type II receptors, and iNOS was statistically significantly increased and expression of MUC1 statistically significantly decreased in tubes bearing an EP. There was no statistically significant difference in the expression of the candidate molecules between the implantation and remote sites. Candidate molecules were also expressed in the trophoblast.
  
  
  CONCLUSIONS
  The pathological expression of candidate molecules by tubes bearing an EP is not involved in the determination of implantation site. Additionally, candidate molecules may play a role in the regulation of trophoblast cells in vivo during early pregnancy.
authors.affiliation: Laboratory Medicine Department, College of Applied Medical Sciences, Umm Al-Qura University, Mecca, Saudi Arabia.
authors.forename: Bassem
authors.initials: B
authors.lastname: Refaat
authors.forename: Hannah
authors.initials: H
authors.lastname: Simpson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Britton
authors.forename: Jhulan
authors.initials: J
authors.lastname: Biswas
authors.forename: Michael
authors.initials: M
authors.lastname: Wells
authors.forename: John D
authors.initials: JD
authors.lastname: Aplin
authors.forename: William
authors.initials: W
authors.lastname: Ledger
mesh_terms: D030301:Activin Receptors, Type II / Q000032:analysis; D000328:Adult; D010064:Embryo Implantation; D004739:England; D005187:Fallopian Tubes / Q000201:enzymology* / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D028322:Inhibin-beta Subunits / Q000032:analysis* / Q000235:genetics; D018396:Mucin-1 / Q000032:analysis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II / Q000032:analysis* / Q000235:genetics; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000201:enzymology / Q000209:etiology* / Q000235:genetics / Q000276:immunology / Q000503:physiopathology; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014327:Trophoblasts / Q000201:enzymology / Q000276:immunology; D055815:Young Adult
chemical_list: C060192:MUC1 protein, human; D018396:Mucin-1; D012333:RNA, Messenger; C103008:inhibin beta A subunit; D028322:Inhibin-beta Subunits; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D030301:Activin Receptors, Type II