title: Early morphological changes leading to central polydactyly, syndactyly, and central deficiencies: an experimental study in rats.
abstract: OBJECTIVE
  Various combinations of central polydactyly, syndactyly, and cleft hand have been frequently observed in the individual hands and feet in the same patients. Little is known, however, about the early changes of abnormal induction of digital rays during limb development. To determine the early changes and process of formation of central polydactyly, syndactyly, and cleft hand, we experimentally induced these anomalies in the hind limbs of rat embryos and discussed the relationship among these abnormalities.
  
  
  METHODS
  Inbred WKAH/Hkm rats were used for this study. Pregnant females were treated with busulfan at embryonic day (E) 11. The embryos were removed at E12 to E21 and stained with alcian blue and alizarin red S. The abnormal changes in the treated embryos' hind limbs were observed with a microscope.
  
  
  RESULTS
  The edges of the footplates were irregular, and their growth was reduced at E14. By E15, abnormal clefts in the distal edge were present that disrupted the central digits (2 to 4) of the footplates. Because of these abnormal clefts, the digital rays were bent or branched, and the neighboring interdigital spaces were narrowed. These changes led to central polydactyly, syndactyly, and central deficiencies.
  
  
  CONCLUSIONS
  These findings show that central polydactyly, syndactyly, and central deficiencies have the same early morphological changes: abnormal clefts in the central part of the footplate.
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University School of Medicine, Yamagata, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Naruse
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takahara
authors.forename: Michiaki
authors.initials: M
authors.lastname: Takagi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ogino
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D002066:Busulfan / Q000494:pharmacology; D004622:Embryo, Mammalian; D005260:Female; D006614:Hindlimb / Q000196:embryology*; D006801:Humans; D007178:Inbreeding; D017880:Limb Deformities, Congenital / Q000196:embryology*; D008853:Microscopy; D023421:Models, Animal; D011247:Pregnancy; D051381:Rats
chemical_list: D018906:Antineoplastic Agents, Alkylating; D002066:Busulfan