title: Postnatal development of the testis in Japanese children based on observations of undescended testes.
abstract: BACKGROUND
  Little is known about the morphological aspects of the postnatal development of the testis in Japanese children. By investigating the normal development of the testis, clinicians in urology can give better strategies to their patients. In addition, the pattern of development will improve the understanding of the effect of xenoestrogens.
  
  
  METHODS
  Biopsied testis samples of 68 patients with undescended testes aged between 2 and 21 years were examined by light microscopy. Nineteen patients with normal histology of the bilateral testes were selected for this study. For light microscopy, paraffin sections were stained with hematoxylin and eosin. In addition, using electron microscope, Epon sections stained with lead citrate and uranyl acetate were observed. Semi-thin sections stained with toluidine blue were also used for light microscopy.
  
  
  RESULTS
  Gonocytes were observed in the testis of the 2-year-old boys. Spermatocytes developed by 4 years of age and spermatids developed by 11 years of age. The immature Sertoli-Sertoli ectoplasmic junction was observed as early as 4 years of age, and it was completed by 9 years of age. Mature myoid cells were observed by the age of 13 years. Immature Leydig cells were found at 7 years of age and the cells matured by 13 years of age.
  
  
  CONCLUSIONS
  A pattern of postnatal development of the testis in Japanese children was presented.
authors.affiliation: Department of Urology, Chiba University School of Medicine, Chiba, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Yuasa
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Toyama
authors.forename: S
authors.initials: S
authors.lastname: Yuasa
authors.forename: M
authors.initials: M
authors.lastname: Masai
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D007564:Japan; D007985:Leydig Cells / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D012016:Reference Values; D012671:Seminiferous Tubules / Q000166:cytology / Q000254:growth & development*; D012708:Sertoli Cells / Q000648:ultrastructure; D013737:Testis / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*