心肌造影超声心动图评估心肌缺血程度的实验研究

本实验制作不同程度心肌缺血的动物模型，以声处理５％人血白蛋白为超声造影剂进行心肌灌注造影，探讨ＭＣＥ时间－强度曲线各指标与心肌缺血程度间的关系。结果表明：心肌显影的峰值强度和曲线下面积均与缺血程度呈显著负相关（相关系数分别为ｒ＝－０．９８，Ｐ值＜０．００５；ｒ＝－０．９４，Ｐ值＜０．０５），且能区分轻度、中度和重度三种程度的心肌缺血；而三项时间指标与心肌缺血程度间未发现显著性差异。本实验的初步结果表明，ＭＣＥ是一项活体评估局部心肌血流灌注的有效方法。     

Distribution of rat facial motoneurons and its reorganization following nerve reinnervation]

OBJECTIVE: To examine the distribution of rat facial motoneurons contributing different branches under normal situation and when nerve reinnervation occurred following facial nerve axotomy. METHODS: The normal distribution of motoneurons innervated both buccal and marginal mandibular branches and its reorganization after facial nerve reinnervation was observed using retrograde labeling with fluorescein. RESULTS: Under normal situation, the motoneurons contributing buccall and marginal mandibular branches were primarily distributed in the intermedial and lateral subnucleus in facial nucleus and almost completely overlapped. The two types labeled neurons organized closely, but there were no double-labeled neurons. Although the motoneurons contributing buccall and marginal mandibular branches were primarily overlapped 4 month post-anastomosis, the number of the labeled neurons obviously decreased and the organization got more scattered. There were 10% of buccall branches, 5% of marginal mandibular motoneurons in the dorsal subnuleus, 1% of buccall and 4% of marginal mandibular in dorsal ventral and medial subnucleus. The distribution pattern of the motoneurons 6 month post-anastomosis was similar to that of 4 month post-anastomosis, but the number of the labeled neurons increased, and there were 1%-2% double-labeled neurons. CONCLUSION: The distribution pattern of motoneurons innervated both buccal and marginal mandibular branches indicates that it should exist wide-spread communicating branches, and its reorganization after facial nerve reinnervation suggests that misdirected regeneration occurs among motoneurons innervating different branches.     

成牙本质细胞中上游刺激因子1对骨桥素表达调控的研究

目的检测成牙本质细胞中上游刺激因子1（upstream stimulatory factor 1，USF1）对骨桥素表达的影响。方法培养成牙本质细胞MDPC-23，稳定转染PCMV-USF1和酸性-USF（A-USF）质粒，提取总RNA，半定量反转录聚合酶链反应检测骨桥素的表达水平，并对结果进行统计学分析。结果筛选出稳定转染USF1和A-USF的抗性克隆，USF1、A-USF转染组和对照组骨桥素相对灰度比值分别为：60．33％±4．51％、229．33％±7．09％、110．00％±15．62％，转染组与对照组差异有统计学意义（P〈0．01）。结论USF1可调控成牙本质细胞骨桥素mRNA转录，该作用被A-USF部分阻断。     

糖皮质激素对哮喘患者白细胞介素-5mRNA表达与嗜酸性粒细胞激活作用的影响

为了观察糖皮质激素对哮喘患者白细胞介素（ＩＬ）－５ｍＲＮＡ表达与嗜酸性粒细胞激活作用的影响，本研究用逆转录（ＲＴ）－聚合酶链反应（ＰＣＲ）法半定量分析了哮喘患者用糖皮质激素治疗前后外周血单个核细胞（ＰＢＭＣ）中ＩＬ－５ｍＲＮＡ表达水平的变化，检测了血清嗜酸细胞阳离子蛋白（ＥＣＰ）浓度、一秒钟用力呼气容积（ＦＥＶ１）下降２０％时的乙酰甲胆碱（ＭＣＨ）激发浓度（ＭＣＨ－ＰＣ２０值）和基础ＦＥＶ１占用力肺活量比值（ＦＥＶ１％）等指标。结果发现，糖皮质激素不仅能改善哮喘患者的气道高反应性和通气功能，而且还可抑制ＰＢＭＣ中ＩＬ－５ｍＲＮＡ的表达和降低血清ＥＣＰ浓度（Ｐ＜０．０５）；血清ＥＣＰ浓度下降幅度或ＭＣＨ－ＰＣ２０值改善幅度与ＩＬ－５ｍＲＮＡ表达水平下降幅度之间均呈显著正相关（ｒ分别为０．５４２６和０．４８５７，Ｐ值＜０．０５）。提示糖皮质激素可能是通过抑制ＩＬ－５基因的转录，从而抑制后者对嗜酸性粒细胞的活化，而发挥其抗气道炎症反应和降低气道高反应性的作用。     

Osteolytic potential of triphenyl bismuth as an alternative contrast medium in acrylic bone cement

Radiopaque cement containing barium sulfate causes significantly more bone resorption in vivo and in vitro than radiolucent cement. The aim of this study was to investigate the osteolytic potential of an alternative radiopaque agent, triphenyl bismuth (TPB). Bone cement particles containing various concentration of TPB (15 and 25 wt %) prepared by two methods, blending and dissolution, were added to monocytes in a bone resorption assay and the extent of lacunar resorption on dentine slices was determined. The results clearly show that cement particles containing TPB cause less bone resorption than cement particles containing barium sulfate. In addition, our results suggest that TPB prepared by dissolution in bone cement induces less osteolytic response than TPB-cement prepared by blending. The osteolysis in response to bone cement wear particles may therefore be reduced with TPB prepared using the blending technique.     

Design and Simulation of Active Biochip System

To solve the problems existing in passive biochip systems, we designed a novel active biochip system. This system introduces negative pressure and controlling devices to adjust the antigen-antibody reaction on the nitrocellulose membrane. Computational simulation demonstrated that this system is a rapid, stable, robust and practical system that may enhance the efficiency of antigen-antibody reactions and improve the repeatability and accuracy of biochip analysis.