牙列缺损的计算机三维建模

目的 建立牙列缺损的计算机三维模型。方法 采用表面绘制法,依据CT扫描头颅骨标本获得的二维断层图像数据在3D Studio Max中沿牙体长轴放样、微调并赋以材质,得到牙列缺损的计算机三维模型。结果 能在计算机中方便快速地模拟任意类型的牙列缺损,并可全方位地旋转、放大和缩小。结论 提供了一种牙列缺损三维建模的新方法,有利于三维义齿专家系统的开发和计算机辅助教学。     

经关节入路微创钢板固定技术治疗股骨远端C型骨折

目的探讨经关节入路微创钢板固定(MIPPO)技术治疗股骨远端C型骨折的临床疗效。方法2002年4月～2005年2月,应用MIPPO技术治疗股骨远端C型骨折14例,按AO/ASIF分类：C1型3例,C2型6例,C3型5例。先行关节内骨折切开复位、松质骨螺钉固定,再行髁上部分骨折间接复位、经关节内切口插入髁支撑钢板或LISS钢板桥接固定骨折。结果12例患者获得10～32个月(平均18．4个月)随访,骨折均获愈合,愈合时间10周～12个月,平均4．6个月。按Kolmert和Wulff的评价标准：优4例,良5例,可2例,差1例,优良率为75%。结论应用MIPPO技术治疗股骨远端C型骨折实现了微创操作,具有创伤小、软组织干扰少、骨折愈合快等优点,疗效满意。     

Protective Effects of Transgenic Human Endothelial Protein C Receptor Expression in Murine Models of Transplantation

Thrombosis and inflammation are major obstacles to successful pig‐to‐human solid organ xenotransplantation. A potential solution is genetic modification of the donor pig to overexpress molecules such as the endothelial protein C receptor (EPCR), which has anticoagulant, anti‐inflammatory and cytoprotective signaling properties. Transgenic mice expressing human EPCR (hEPCR) were generated and characterized to test this approach. hEPCR was expressed widely and its compatibility with the mouse protein C pathway was evident from the anticoagulant phenotype of the transgenic mice, which exhibited a prolonged tail bleeding time and resistance to collagen‐induced thrombosis. hEPCR mice were protected in a model of warm renal ischemia reperfusion injury compared to wild type (WT) littermates (mean serum creatinine 39.0 ± 2.3 μmol/L vs. 78.5 ± 10.0 μmol/L, p < 0.05; mean injury score 31 ± 7% vs. 56 ± 5%, p < 0.05). Heterotopic cardiac xenografts from hEPCR mice showed a small but significant prolongation of survival in C6‐deficient PVG rat recipients compared to WT grafts (median graft survival 6 vs. 5 days, p < 0.05), with less hemorrhage and edema in rejected transgenic grafts. These data indicate that it is possible to overexpress EPCR at a sufficient level to provide protection against transplant‐related thrombotic and inflammatory injury, without detrimental effects in the donor animal.     

Identification and characterization of novel uroporphyrinogen decarboxylase gene mutations in a large series of porphyria cutanea tarda patients and relatives

Porphyria cutanea tarda (PCT) arises from decreased hepatic activity of uroporphyrinogen decarboxylase (UROD). Both genetic and environmental factors interplay in the precipitation of clinically overt PCT, but these factors may vary between different geographic areas. Decreased activity of UROD in erythrocytes was used to identify patients with UROD mutations among a group of 130 Spanish PCT patients. Nineteen patients (14.6%) were found to harbor a mutation in the UROD gene. Eight mutations were novel: M1I, 5del10, A22V, D79N, F84I, Q116X, T141I and Y182C. Five others were previously described: F46L, V134Q, R142Q, P150L and E218G. The new missense mutations and P150L were expressed in Escherichia coli. D79N and P150L resulted in proteins that were localized to inclusion bodies. The other mutations produced recombinant proteins that were purified and showed reduced activity (range: 2.3–73.2% of wild type). These single amino acid changes were predicted to produce complex structural alterations and/or reduced stability of the enzyme. Screening of relatives of the probands showed that 37.5% of mutation carriers demonstrated increased urinary porphyrins. This study emphasizes the role of UROD mutations as a strong risk factor for PCT even in areas where environmental factors (hepatitis C virus) have been shown to be highly associated with the disease.     

变应性鼻炎脱敏治疗的效果观察

目的观察变应性鼻炎（AR）脱敏治疗的效果，探讨影响变应性鼻炎脱敏治疗效果的相关因素。方法对185例AR患者通过皮肤试验，选择敏感变应原浸液，按递增剂量进行常规皮下脱敏治疗。根据患者治疗前后的症状和体征得分情况，分为显效、有效和无效。选择性别、年龄、病程、病情、伴慢性鼻窦炎、伴哮喘、脱敏治疗时间、皮试反应等8个影响变应性鼻炎脱敏治疗效果的可能因素进行多元回归分析，筛查影响脱敏治疗效果的因素。结果总有效率74．6％，其中显效22．9％，有效51．7％。影响脱敏治疗效果的主要因素是治疗时间，即时间越长，效果越好（P〈0．01）；其次是年龄因素，年龄越小，效果越好（P〈0．05）；伴慢性鼻窦炎和伴哮喘也可能影响脱敏治疗效果（P值分别为0．072和0．069）。结论变应性鼻炎脱敏治疗是有效的，脱敏治疗时间越长、年龄越小，效果越好。     

Reversing antibiotic resistance

Over the past decade many well-tried chemotherapeutic agents have lost their effectiveness. This is due to a phenomenon referred to as multi-drug resistance. The most likely cause of multi-drug resistance is an increase in the activity of an efflux pump mediated through the actions of a P-glycoprotein. There is a continuing search, not only for new chemotherapeutic agents, but also for agents that can reverse the acquired resistance to existing agents.     

A novel form of autosomal recessive pure hereditary spastic paraplegia maps to chromosome 13q14

BACKGROUND: Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous disorder characterized by a progressive weakening and spasticity of the lower limbs. HSP is classified according to the presence or absence of accompanying neurologic problems and by the mode of inheritance. Currently, 17 loci have been linked to the various forms of HSP. OBJECTIVE: To determine the chromosomal location of a gene causing pure autosomal recessive spastic paraplegia. METHODS: Genotyping using fluorescently labeled microsatellite markers was performed on three affected individuals and three unaffected individuals from a family displaying pure autosomal recessive HSP (ARHSP) and sensorineural deafness. All family members were then included in the analysis to narrow the genetic interval. Candidate genes were screened for the presence of mutations by heteroduplex analysis. RESULTS: The paraplegic trait linked to a 1.8-Mb region of chromosome 13q14 flanked by the FLJ11712 gene and the microsatellite marker D13S270. The deafness did not link to this region and did not cosegregate with the paraplegic trait. CONCLUSION: The HSP that this family had represents a novel genetic form of pure ARHSP as no other form of HSP (autosomal dominant or recessive) has been linked to chromosome 13.     

下肢骨肉瘤的MRI与X线对照研究

目的 对比分析下肢骨肉瘤的X线与MRI表现，探讨MRI对骨肉瘤的诊断价值。方法 收集经手术或病理穿刺活检证实的下肢骨肉瘤15例，男11例，女4例，均行MRI平扫及增强扫描（4例行CT扫描），并摄有X线平片，对其MRI征象与X线征象作逐一对比。结果 MRI及X线平片对下肢骨肉瘤的诊断准确率均为100％，MRI在显示病变范围、放射状骨针、Codman三角两层结构以及跳跃病灶等方面明显优于X线平片检查。结论 X线平片是诊断骨肉瘤最简便而实用的方法，但MRI可以更好的显示病变的范围，发现早期病变。