18三体腭裂小鼠颅上颌复合体发育的比较组织形态学研究

Comparative Histomorphological Study on the Craniomaxillary Development of the Trisomy-18 with Cleft Palate and Euploid Mice

目的 :研究 18三体腭裂小鼠实验动物模型的颅上颌复合体组织学发育异常。方法 :30对胎鼠 (每对包括 1只正常胎鼠和 1只与其体重相近的三体腭裂的胎鼠 )的颅上颌复合体分别作序列连续切片 (厚度 7μm) ,再从每组序列切片中选择 6张有特殊结构的特征切片 ,并借助显微形态学的研究手段对各特征切片中的特殊结构进行比较组织形态学观察研究。结果 :该模型虽无原发腭裂却伴有原发腭的发育不足 ;腭裂组上腭骨性结构及鼻中隔内硬组织 (包括鼻中隔软骨、鼻中隔旁软骨及犁骨等 )呈现明显的发育障碍 ;腭裂样本伴有明显的腭咽闭合不全 (VIP)鼻囊发育扁平。结论 :18三体腭裂小鼠颅上颌复合体的发育伴有严重的硬组织发育障碍和不足 ,可能与其常染色体三体密切相关。

Objective: The aim of this study is to compare histological morphology of craniomaxillary complex of Trisomy 18 with cleft palate (Ts+CP) and euploid mouse foetuses to understand whether cleft palate is associated with maldevelopment of the craniomaxillary complex or with hypoplasia of the adjacent tissues. Methods: Thirty pairs of Ts+CP and euploid mouse foetuses with about equal body weight were selected, and sixty craniomaxillary complex were precisely orientated in the coronal plane, then serially sectioned with 7 μm thickness through the primary palate, the whole hard palate and the soft palate. Finally six sections were selected for comparative histomorphological study based on anatomical landmarks. Results: The trisomy with cleft palate mouse foetuses had significantly developmental hypoplasia in the primary palatal shelves. The palatal shelves, vomer, palatal bone and nasal septal cartilage in cleft samples showed significantly developmental hypoplasia with a relatively wider nasal septum, nasal capsule and a bigger nasal airway volume, nasopharyngeal cavity. Conclusion: The hard tissues of the craniomaxillary complex in Ts+CP mouse foetuses, including bone and cartilage show serious maldevelopment or developmental hypoplasia, and these may be closely related to the autosomal trisomic condition. \;