While the recent release of the Chinese tree shrew （Tupaia belangeri chinensis） genome has made the tree shrew an increasingly viable experimental animal model for biomedical research, further study of the genome ma...While the recent release of the Chinese tree shrew （Tupaia belangeri chinensis） genome has made the tree shrew an increasingly viable experimental animal model for biomedical research, further study of the genome may facilitate new insights into the applicability of this model. For example, though the tree shrew has a rapid rate of speed and strong jumping ability, there are limited studies on its locomotion ability. In this study we used the available Chinese tree shrew genome information and compared the evolutionary pattern of 407 locomotion system related orthologs among five mammals （human, rhesus monkey, mouse, rat and dog） and the Chinese tree shrew. Our analyses identified 29 genes with significantly high co （Ka/Ks ratio） values and 48 amino acid sites in 14 genes showed significant evidence of positive selection in the Chinese tree shrew. Some of these positively selected genes, e.g. HOXA6 （homeobox A6） and AVP （arginine vasopressin）, play important roles in muscle contraction or skeletal morphogenesis. These results provide important clues in understanding the genetic bases of locomotor adaptation in the Chinese tree shrew.展开更多
Objective： To establish an animal model to replicate the blunt impact brain injury in forensic medicine. Methods： Twenty-four New Zealand white rabbits were randomly divided into control group （n=4）, minor injury...Objective： To establish an animal model to replicate the blunt impact brain injury in forensic medicine. Methods： Twenty-four New Zealand white rabbits were randomly divided into control group （n=4）, minor injury group （n：10） and severe injury group （n=10）. Based on the BIM- II Horizontal Bio-impact Machine, self-designed iron bar was used to produce blunt brain injury. Two rabbits from each injury group were randomly selected to monitor the change ofintracranial pressure （ICP） during the impact- ing process by pressure microsensors. Six hours after injury, all the rabbits were dissected to observe the injury mor- phology and underwent routine pathological examination. Results： Varying degrees of nervous system positive signs were observed in all the injured rabbits. Within 6 hours, the mortality rate was 1/10 in the minor injury group and 6/10 in the severe injury group. Morphological changes con-sisted of different levels of scalp hematoma, skull fracture, epidural hematoma, subdural hematoma, subarachnoid hemo- rrhage and brain injury. At the moment of hitting, the ICP was greater in severe injury group than in mild injury group; and within the same group, the impact side showed positive pressure while the opposite side showed negative pressure. Conclusions： Under the rigidly-controlled experimental condition, this animal model has a good reproducibility and stable results. Meanwhile, it is able to simulate the morphology of iron strike-induced injury, thus can be used to study the mechanism of blunt head injury in forensic medicine.展开更多
基金Foundation items： This study was supported by the National 863 Project of China （2012AA021801, 2012AA022402） and grants from Chinese Academy of Sciences （KSCX2-EW-R-11, KSCX2-EW-J23） and Yunnan Province （2013FB071）Acknowledgements： We are grateful to Dr. Dong WANG for helpful discussion.
文摘While the recent release of the Chinese tree shrew （Tupaia belangeri chinensis） genome has made the tree shrew an increasingly viable experimental animal model for biomedical research, further study of the genome may facilitate new insights into the applicability of this model. For example, though the tree shrew has a rapid rate of speed and strong jumping ability, there are limited studies on its locomotion ability. In this study we used the available Chinese tree shrew genome information and compared the evolutionary pattern of 407 locomotion system related orthologs among five mammals （human, rhesus monkey, mouse, rat and dog） and the Chinese tree shrew. Our analyses identified 29 genes with significantly high co （Ka/Ks ratio） values and 48 amino acid sites in 14 genes showed significant evidence of positive selection in the Chinese tree shrew. Some of these positively selected genes, e.g. HOXA6 （homeobox A6） and AVP （arginine vasopressin）, play important roles in muscle contraction or skeletal morphogenesis. These results provide important clues in understanding the genetic bases of locomotor adaptation in the Chinese tree shrew.
基金This study was supported Dy grants trom the National Natural Science Foundation （No. 30800243, 31170908, 81072504）, Chongqing Municipal Science and Technology Program （CSTC. 2005BA6020, 2005AB60022, 2009AB0208） and Ministry of Public Security Program （No. ZDYJCQSJ007）
文摘Objective： To establish an animal model to replicate the blunt impact brain injury in forensic medicine. Methods： Twenty-four New Zealand white rabbits were randomly divided into control group （n=4）, minor injury group （n：10） and severe injury group （n=10）. Based on the BIM- II Horizontal Bio-impact Machine, self-designed iron bar was used to produce blunt brain injury. Two rabbits from each injury group were randomly selected to monitor the change ofintracranial pressure （ICP） during the impact- ing process by pressure microsensors. Six hours after injury, all the rabbits were dissected to observe the injury mor- phology and underwent routine pathological examination. Results： Varying degrees of nervous system positive signs were observed in all the injured rabbits. Within 6 hours, the mortality rate was 1/10 in the minor injury group and 6/10 in the severe injury group. Morphological changes con-sisted of different levels of scalp hematoma, skull fracture, epidural hematoma, subdural hematoma, subarachnoid hemo- rrhage and brain injury. At the moment of hitting, the ICP was greater in severe injury group than in mild injury group; and within the same group, the impact side showed positive pressure while the opposite side showed negative pressure. Conclusions： Under the rigidly-controlled experimental condition, this animal model has a good reproducibility and stable results. Meanwhile, it is able to simulate the morphology of iron strike-induced injury, thus can be used to study the mechanism of blunt head injury in forensic medicine.
