超声诊断1例肺动脉瓣下膜型狭窄

单纯肺动脉瓣下膜型狭窄少见,用超声诊断本病尚未见报告。今报告1例同时合并非特异性心包炎,术前经心导管及左、右心造影,其后又经手术证实。

Histopathological and genetic differences between polypoid and non-polypoid submucosal colorectal carcinoma

AIM： To investigate the histopathological and geneticdifferences between polypoid growth （PG） and nonpolypoid growth （NPG） submucosal invasive colorectal carcinoma （CRC）.METHODS： A total of 96 cases of submucosal CRC were divided into two groups according to their growth type;60 cases of PG and 36 cases of NPG. The size, histological degree of dysplasia, depth of submucosal invasion and lymph node metastasis were compared between the two groups. Furthermore, expression of p53 was detected by immunohistochemical staining, and K-ras gene mutation was examined by polymerase chain reaction based single-strand conformation polymorphism （SSCP）.RESULTS： The average size of the lesions in the NPG group was significantly smaller than those in the PG group （7.5 mm vs 13.8 mm, P 〈 0.001）. The histological degree of dysplasia tended to be more severe in NPG group, while the incidence of submucosal massive invasion and the lymph node metastasis were both significantly higher in the NPG type than in the PG group （64.3% vs 43.3%, P = 0.004; 43% vs 7%, P =0.008, respectively）. In addition, K-ras gene mutations were detected in 67% of lesions in the PG group, but none in the NPG group, while no difference in p53immunohistochemical expression was found between the two groups.CONCLUSION： Compared with PG submucosal CRC,NPG type demonstrates more frequent submucosal massive invasion, more lymph node metastasis and a higher degree dysplasia. Genetically, NPG type shows much less frequent K-ras mutation.

Establishment of a blunt impact-induced brain injury model in rabbits

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.