Neural tube defects （NTDs） are severe congenital malformation diseases, which occur in 1 out of 1000 births in human. In Xenopus, several tissue movements are involved in the neural tube closure process. Immediately...Neural tube defects （NTDs） are severe congenital malformation diseases, which occur in 1 out of 1000 births in human. In Xenopus, several tissue movements are involved in the neural tube closure process. Immediately after the neural tube fusion, the neural crest cells get monopolar protrusion toward dorsal midline and migrate to form the roof of the neural tube. At the same time, radial intercalation takes place from the ventral neural tube and forces it to be single-layered. Here, we physically block the neural tube closure to test the cell movements and the following patterning in Xenopus laevis explants. The results show that the single-layered neural tube fails to form and the neural crest cells remain at the lateral regions in the explants with NTDs. However, the patterning of the neural tube is not affected as indicated by the normal expression of the preneural genes. These results indicate a requirement of the neural tube fusion for the radial intercalation and the dorsal midline directed neural crest migration, but not for the dorsal-ventral patterning of the neural tube.展开更多
Objective： To study the patterns and morphologic characteristics of blunt head injury and analyse its formative mechanism in attempt to provide references for medicolegal expertise. Methods： The statistical analysi...Objective： To study the patterns and morphologic characteristics of blunt head injury and analyse its formative mechanism in attempt to provide references for medicolegal expertise. Methods： The statistical analysis was done in terms of gender, age, as well as the nature, pattern, location, and feature of the injuries. Results： Among the 202 cases of head injury-induced death, 124 were male and 78 female with the age ranging from 1-81 years. Death caused by homicide was dominant （106, 52.5%）, followed by suicide （49, 24.3%） and accident （44, 21.8%）. The majority of suicide-induced death were byfalling from height, and traffic crash was responsible for majority of unexpected death cases. The morphology and pathogenesis of the injuries varied according to differences on the mode, magnitude, and orientation of the outside force giving rise to blunt injury as well as the character of vulnerants. Conclusion： Studies on the morphology and its forma- tive rationale of blunt head injury will offer easy access to medicolegal expertise on the mode and character of the injury.展开更多
基金supported by grants from the National Natural Science Foundation of China (30425011 30530380)the Innovation Project of the Chinese Academy of Sciences (KSCX2-YW-R-090)~~
文摘Neural tube defects （NTDs） are severe congenital malformation diseases, which occur in 1 out of 1000 births in human. In Xenopus, several tissue movements are involved in the neural tube closure process. Immediately after the neural tube fusion, the neural crest cells get monopolar protrusion toward dorsal midline and migrate to form the roof of the neural tube. At the same time, radial intercalation takes place from the ventral neural tube and forces it to be single-layered. Here, we physically block the neural tube closure to test the cell movements and the following patterning in Xenopus laevis explants. The results show that the single-layered neural tube fails to form and the neural crest cells remain at the lateral regions in the explants with NTDs. However, the patterning of the neural tube is not affected as indicated by the normal expression of the preneural genes. These results indicate a requirement of the neural tube fusion for the radial intercalation and the dorsal midline directed neural crest migration, but not for the dorsal-ventral patterning of the neural tube.
文摘Objective： To study the patterns and morphologic characteristics of blunt head injury and analyse its formative mechanism in attempt to provide references for medicolegal expertise. Methods： The statistical analysis was done in terms of gender, age, as well as the nature, pattern, location, and feature of the injuries. Results： Among the 202 cases of head injury-induced death, 124 were male and 78 female with the age ranging from 1-81 years. Death caused by homicide was dominant （106, 52.5%）, followed by suicide （49, 24.3%） and accident （44, 21.8%）. The majority of suicide-induced death were byfalling from height, and traffic crash was responsible for majority of unexpected death cases. The morphology and pathogenesis of the injuries varied according to differences on the mode, magnitude, and orientation of the outside force giving rise to blunt injury as well as the character of vulnerants. Conclusion： Studies on the morphology and its forma- tive rationale of blunt head injury will offer easy access to medicolegal expertise on the mode and character of the injury.
