Résumé
Molecular interactions between epithelium and mesenchyme are important for root formation. Nuclear factor I-C (Nfic) has been identified as a key regulator of root formation. However, the mechanisms of root formation and their interactions between Hertwig's epithelial root sheath (HERS) and mesenchyme remain unclear. In this study, we investigated the role of Nfic in root patterning and growth during molar root development. The molars of Nfic knockout mice exhibited an enlarged pulp chamber and apical displacement of the pulpal floor, characteristic features of taurodontism, due to delayed furcation formation. In developing molar roots of mutant mice at P14, BrdU positive cells decreased in the apical mesenchyme of the elongation region whereas those cells increased in the dental papilla of the furcation region. Whereas cytokeratin 14 and laminin were localized in HERS cells of mutant molars, Smoothened (Smo) and Gli1 were downregulated in preodontoblasts. In contrast, cytokeratin 14 and Smo were localized in the cells of the furcation region of mutant molars. These results indicate that Nfic regulates cell proliferation in the dental mesenchyme and affects the fate of HERS cells in a site-specific manner. From the results, it is suggested that Nfic is required for root patterning and growth during root morphogenesis.
Sujets)
Animaux , Souris , Broxuridine , Prolifération cellulaire , Papille dentaire , Cavité pulpaire de la dent , Épithélium , Kératine-14 , Laminine , Mésoderme , Souris knockout , Molaire , Morphogenèse , Facteurs nucléaires-I , Racine dentaire , DentRésumé
Objective To evaluate a modified operation for the treatment of urethral hymenal fusion. Methods 45 case underwent the modified meatoplasty.The key points of the operative procedure were excision of the pathological changes at the external meatus and widened the distance between the external meatus and ostium vaginae to 1.2～1.5 cm. Results 43 case (96%) have been followed up for 3～48 months with 37(86%) cured of the disease and 2(5%) patients were improved.The operation failed in 4(9%). Conclusions The modified operation was claimed to be simple and effective for the treatment of urethtal hymenal fusion.