核糖核酸的酶消化方法直接顺序分析

应用硷基特异性核酸内切酶进行RNA的顺序分析。以~(32)P标记RNA分子的5′或3′末端的四种硷基能被酶试剂部分裂解。放射性的水解产物经胶电泳按其大小而分离。放射自显影后它的核苷酸顺序从带谱上可以直接读出。核糖核酸酶(RNasc)T_1(G特异性)、U_2(A特异性)、Phy M(U+A特异性)和B.cereus(C+U特异性)是最常用于顺序RNA的四种酶。     

地震灾害对分娩的影响

目的:观察地震灾害对分娩的影响。方法:对我院2008年5月12日至2008年6月12日在地震期间分娩的216例产妇进行回顾性分析。结果:阴道分娩率较地震前比较明显上升,剖宫产率明显下降。结论:地震灾害致孕妇的心理发生变化,导致阴道分娩率上升剖宫产率明显下降。     

Synergistic effects of Nell-1 and BMP-2 on the osteogenic differentiation of myoblasts.

Osteogenesis is synergistically enhanced by the combined effect of complimentary factors. This study showed that Nell-1 and BMP-2 synergistically enhanced osteogenic differentiation of myoblasts and phosphorylated the JNK MAPK pathway. The findings are important because of the osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of coordinated BMP-2 and Nell-1 delivery. INTRODUCTION: BMPs play an important role in the migration and proliferation of mesenchymal cells and have a unique ability to alter the differentiation of mesenchymal cells toward chondrogenic and osteogenic lineages. Signaling upstream of Cbfa1/Runx2, BMPs effects are not limited to cells of the osteoblast lineage. Thus, additional osteoblast-specific factors that could synergize with BMP-2 would be advantageous for bone regeneration procedures. NELL-1 (NEL-like molecule-1; NEL [a protein strongly expressed in neural tissue encoding epidermal growth factor like domain]) is a novel growth factor believed to preferentially target cells committed to the osteochondral lineage. MATERIALS AND METHODS: C2C12 myoblasts were transduced with AdLacZ, AdNell-1, AdBMP-2, or AdNell-1+AdBMP-2 overexpression viruses. Effects were studied by cell morphology, alkaline phosphatase activity, osteopontin production, and MAPK signaling. Additionally, in a nude mouse model, viruses were injected into leg muscles, and new bone formation was examined after 2 and 8 wk. RESULTS: C2C12 myoblasts co-transduced with AdNell-1+AdBMP-2 showed a synergistic effect on osteogenic differentiation as detected by alkaline phosphatase activity and osteopontin production. Nell-1 stimulation on AdNell-1 + AdBMP-2 preconditioned C2C12 cells revealed significant activation of the non-BMP-2 associated c-Jun N-terminal kinase (JNK) MAPK signaling pathway, but not the p38 or extracellular signal-regulated kinase (ERK1/2) MAPK pathways. Importantly Nell-1 alone did not induce osteogenic differentiation of myoblasts. In a nude mouse model, injection of AdNell-1 alone stimulated no bone formation within muscle; however, injection of AdNell-1+AdBMP-2 stimulated a synergistic increase in bone formation compared with AdBMP-2 alone. CONCLUSIONS: These findings are important because of the confirmed osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of enhanced BMP-2 action with coordinated Nell-1 delivery.     

股骨头骨坏死样本空间结构的Micro-CT评估

目的以股骨头骨坏死样本的Micro-CT断层图像为基础，对其进行空间结构评估。方法2003年11月～2005年6月，收集股骨头骨坏死患者行全髋关节置换术时取出的股骨头样本6个，对样本进行Micro-CT断层扫描，获取股骨头骨坏死样本的计算机三维图像，图像空间分辨率为36μm×36μm×36μm。手工选取兴趣区，随后采用骨体积分数（BV／TV）、骨小梁间隙（Tb．Sp）、骨小梁厚度（Tb，Th）、骨小梁数目（Tb．N）、骨表面积体积比（BS／BV）、结构模型指数（SMI）、骨小梁模型因子（Tb．Pf）等三维空间参数分别对股骨头骨坏死标本的正常区域、硬化带和塌陷区进行评价。结果晚期股骨头骨坏死硬化区和塌陷区的骨小梁空间结构明显改变：硬化区Bv／Tv明显增加，Tb．Th明显增厚，Tb，Sp变窄，SMI与正常区域的骨小梁无差别；而塌陷区Bv／Tv明显减少，BS／BV增大，Tb．N和Tb．Pf增加，Tb，Th改变不明显。结论Micro-CT作为一种新的检测手段，能够在不损伤样本的条件下快速获取股骨头骨坏死样本断层图像，具有精度高、检测快、可进行三维重建分析的优点。晚期股骨头骨坏死不同区域的骨三维结构呈现出不同的空间结构特征。     

蛋白酶对降低异常精液粘稠度的实验对比研究

目的通过不同蛋白酶类对降低高粘稠度精液的粘稠度效果对比,寻找理想的降低精液粘稠度的药物。方法将高粘稠度精液标本分为两组,A组:31例采用α-糜蛋白酶降低精液粘稠度:B组:32例采用尿激酶降低精液粘稠度;两组均观察用药前后的精子活动力。采用配对t检验和单因素方差分析对所得数据作统计学处理。结果高粘稠度精液用药物(α-糜蛋白酶或者尿激酶)液化精液后,精子的活动力较用药前有明显提高(P<0．001);用药前后精液的粘稠度都存在着明显的差异,精液的粘稠度分别下降44．83％和55．45％(P<0．001);在A组和B组的对比研究中,单因素方差分析检验提示:用药后两组间粘稠度数据有显著的差异(P<0．001￡(?)。结论蛋白酶可以有效地降低异常精液粘稠度的精液,从实验结果提示尿激酶降低精液粘稠度的效果优于α-糜蛋白酶,这有助于临床开展应用性研究和治疗。     

Using rare earth element tracers and neutron activation analysis to study rill erosion process.

Spatially averaged soil erosion data provide little information on the process of rill erosion. The dynamically varied data on the temporal and spatial distributions in the rill erosion process are needed to better understand the erosion process and reveal its innate characteristics. The objectives of this study were to examine the feasibility and effectiveness of rare earth element (REE) tracers and the neutron activation analysis (NAA) method on the study of the rill erosion process and to reveal quantitatively the relationships and characteristics of temporal and spatial distributions of sediment yield in rill erosion. Four REEs were used to study the changeable process of rill erosion at 4 slope positions. Four water inflow rates were applied to a 0.3 x 5 m soil bed at 3 slopes of 10.5%, 15.8% and 21.2% in scouring experiments. All of the runoff was collected in the experiment. Each sample was air-dried and well mixed. Then 20 g of each sample was sieved through 100-mesh and about a 50 mg sample was weighed for analysis of the four elemental compositions by NAA. Results indicate that the REE tracers and NAA method can be used to not only quantitatively determine soil erosion amounts on different slope segments, but also to reveal the changeable process of rill erosion amount. All of the relative errors of the experimental results were less than 25%, which is considered satisfactory on the study of rill erosion process.     

The role of endotoxin in the pathogenesis of experimental multiple system organ failure: a preliminary report.

In this study, an animal model of multiple system organ failure (MSOF) in rabbits, engendered by feeding E. coli prior to severe hemorrhagic shock, was used for the purpose of investigating 1) the relationship between lipopolysaccharide (LPS) and MSOF, and 2) the effectiveness of Re-LPS antiserum in preventing MSOF. The results showed that endotoxemia occurred very early, and its degree correlated well with that of organ dysfunction. Re-LPS antiserum administration abated the toxic effects and lowered the incidence of MSOF. These results suggest that sequential analysis of circulating LPS levels may be useful for the early diagnosis of MSOF, and that gut-derived endotoxin might play an important role in the pathogenesis of experimental MSOF.     

细胞内游离Ca2+在发育中大鼠皮层神经元无镁诱导惊厥性损伤中的作用

目的: 观察细胞内游离Ca2+([Ca2+]i)在培养的不同发育阶段皮层神经元无镁诱导惊厥性损伤中的作用,探讨惊厥性脑损伤年龄依赖性的可能机制.方法:体外培养6 d、17 d的胚胎大鼠皮层神经元用无镁细胞外液处理3 h,或于无镁处理前用NMDA(N-甲基-D-门冬氨酸)受体拮抗剂或Ca2+通道阻滞剂预处理,用MTT代谢率测定的方法检测神经元损伤,以Fluo-3作标记用激光共聚焦显微镜扫描的方法检测[Ca2+]i.结果:体外培养6 d、17 d的神经元单纯无镁组MTT代谢率较同期对照组降低.应用MK-801 10 μmol*L-1、AP-5 50 μmol*L-1、尼莫地平10 μmol*L-1预处理后再给无镁处理,培养6 d、17 d的神经元MTT代谢率均不同程度高于同期单纯无镁组.培养6 d、17 d的神经元相对荧光强度之间差异有显著性,两者与基线荧光强度比较差异亦有显著性.应用上述各种拮抗剂后,[Ca2+]i改变的峰值均明显低于同期单纯无镁组.结论: 在体外不同发育阶段的神经元,短暂无镁处理诱导惊厥样放电所引起的神经元线粒体功能损伤以及[Ca2+]i改变程度不同.这种[Ca2+]i改变的年龄依赖性可能是惊厥导致神经元损伤的年龄依赖性的机制之一.NMDA受体-Ca2+通道激活是导致这种[Ca2+]i改变及神经元损伤的关键环节.     

外伤性股动脉栓塞继发肾功能衰竭32例的综合治疗

目的 探讨外伤性股动脉栓塞后继发急性肾功能衰竭的临床综合治疗。方法 对32例外伤性股动脉栓塞术后继发急性肾功能衰竭病例均进行急诊手术切开取栓、血管吻合术，术后均予以综合治疗。结果住院时间7天-3个月，平均41d。最终截肢6例，死亡2例，24例修复成功。结论 术前准确判断预后，正确选择手术方式、术中筋膜减张性切开、术后及时清除坏死组织、术后利尿合剂应用和及时必要的血透是影响外伤性股动脉栓塞保肢术后急性肾功能衰竭预后的重要因素。     

神经导航下经岩骨幕上下联合入路中面神经管的解剖研究

OBJECTIVE: To study the value of neuronavigation in the transpetroal approach, and to provide anatomic data for the protection of the nerves in the facial nerve canal (FNC) during surgeries. METHODS: Simulated surgery through the transpetroal approach was performed on 16 sides of 8 adult cadaver heads with the assistance by neuronavigation. The anatomy of the facial nerve and the relationship of related structures were observed and the distances from the utmost external edge of the mastoid to different segments of the FNC were measured. RESULTS: Neuronavigation was successful with all the FNC, with the mean error of less than 0.9 mm. The FNC could be divided into 3 segments, the labyrinthine, the tympanic and the mastoid segments, stretching 3.6+/-1.2 mm, 11.2+/-2.5 mm and 16.1+/-3.6 mm respectively and with diameters of 1.2+/-0.3 mm, 1.4+/-0.1 mm and 1.7+/-0.2 mm, respectively. CONCLUSION: Neuronavigation may help protect the FNC during surgical procedures, and a thorough knowledge of the anatomic features of the FNC can be significant for preservation of the facial nerves.