title: The role of smooth muscle cell differentiation in the mechanism of obliteration of processus vaginalis.
abstract: OBJECTIVE
  Development of indirect inguinal hernia and hydrocele in childhood is readily explained by the persistence of smooth muscle component around the processus vaginalis (PV) after the descent of the testis into the scrotum. The aim of this study was to investigate the expression of smooth muscle myosin heavy chain (SM MHC) isoforms as the markers of smooth muscle cell (SMC) differentiation in childhood inguinal hernia and hydrocele and in age-matched controls.
  
  
  METHODS
  The authors analyzed sacs from patients with inguinal hernia (male, 10; female, 10) and hydrocele (n = 10) immunohistochemically using monoclonal antibodies against alpha-smooth muscle actin, SM1, SM2 and SMemb. Peritoneal samples (male, 5; female, 5) obtained from age-matched patients served as controls. Immunostaining was evaluated with semiquantitative scoring and chi2 test.
  
  
  RESULTS
  The expression pattern of SM MHC isoforms did not differ among sacs obtained from female inguinal hernia when compared with that of controls. However, strong expression of SMemb within the sac walls of male inguinal hernia and SM1 in hydrocele groups were observed.
  
  
  CONCLUSIONS
  Our results indicate that SMC differentiation may play an important role in the obliteration of processus vaginalis in male inguinal hernia and hydrocele after the descent of the testis.
authors.affiliation: Department of Pediatric Surgery, Dr. Behcet Uz Children's Hospital, Izmir, Turkey.
authors.forename: Munevver
authors.initials: M
authors.lastname: Hosgor
authors.forename: Irfan
authors.initials: I
authors.lastname: Karaca
authors.forename: Erdener
authors.initials: E
authors.lastname: Ozer
authors.forename: Gulsun
authors.initials: G
authors.lastname: Erdag
authors.forename: Cagnur
authors.initials: C
authors.lastname: Ulukus
authors.forename: Orhan
authors.initials: O
authors.lastname: Fescekoglu
authors.forename: Masanori
authors.initials: M
authors.lastname: Aikawa
mesh_terms: D000199:Actins / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D002675:Child, Preschool; D005260:Female; D006552:Hernia, Inguinal / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000032:analysis*; D010537:Peritoneum / Q000473:pathology; D012016:Reference Values; D006848:Testicular Hydrocele / Q000473:pathology* / Q000601:surgery
chemical_list: D000199:Actins; D015415:Biomarkers; D018995:Myosin Heavy Chains