Objective To investigate problems in applying clinical epidemiology and evidence-based medicine in the field of dentistry in China. Method In early April of 2001, about 200 copies of a questionnaire were sent to chief editors of dental journals, directors and famous experts of the university dental schools and/or dental departments of the provincial/metropolitan hospitals located in the mainland of China. The sent back questionnaires were summarized and analysized. Results At the end of June, 2001, 40 replies from the experts of 12 universities and one metropolitan dental hospital were received. The main points are summarized as following: EBM in China is at starting stage of "anti-illiteracy" campaign. There are 6 out of 12 universities having delivered clinical epidemiology courses to postgraduates (2 to undergraduates), only 3 added lectures on evidence-based medicine to dental students and/or professionals, only one university held intensive training courses on EBM to clinicians. In dental practice there are still scram dentists making decisions simply by experiences. In the research practice some dentists are eager for quick success, and instant benefits, ignoring, scientific design aid quality control of the studies. Randomized controlled clinical trials are seldom appeared in Chinese dental journals. To popularize EBM in all dental clinicians is important for them to use and produce the best evidences. Conclusions EBM in dental field of China is at starling stage. Collection and dissemination of best dental evidences in dental professionals is a key to raise the dental care levels in China.
目的 构建小鼠甲状腺转录因子-2（TTF-2）转基因动物表达载体（pBROAD3-TTF-2），观察其在小鼠骨髓间充质干细胞（BMSC）中的表达。 方法 从C57BL/6J小鼠肝脏组织中提取基因组DNA，利用聚合酶链式反应方法扩增出TTF-2基因1 113 bp开放阅读框，通过DNA重组技术将TTF-2基因片段插入克隆载体pMD18-T中，经测序正确后，再重组于pBROAD3-mcs中，构建转基因动物表达载体pBROAD3-TTF-2，用酶切电泳分析对其进行鉴定。运用脂质体转染试剂将其转染BMSC后，蛋白质印迹法检测TTF-2基因的表达。 结果 ① DNA测序证实目的基因序列正确无突变，酶切电泳分析得到相应的目的片段，大小与理论计算值一致，成功构建转基因动物表达载体pBROAD3-TTF-2。② 蛋白质印迹法显示转染的BMSC高表达TTF-2蛋白。 结论 成功构建了pBROAD3- TTF-2转基因动物表达载体，显示其转染BMSC后TTF-2基因的表达，为下一步建立TTF-2转基因小鼠模型奠定了基础。
ObjectiveTo study the expression of cyclooxygenase2 (COX2) and its clinical significance in gastric carcinoma. MethodsThe expression of COX2 in 47 cases of gastric carcinoma and 16 cases of normal gastric tissue were detected by SP immunohistochemical technique. Helicobacter pylori (H.pylori) infection was diagnosed by urease experiment and Giemsa staining.ResultsThere was no positive signal of COX2 detected in normal gastric tissue. The positive expression rate of COX2 was 63.8%(30/47) in gastric carcinoma.The expression of COX2 was correlated with TNM stage, lymph node metastasis and H.pylori infection（P＜0.01）. Positive COX2 expression rate in H.pylori infection group was 72.4%(21/29), significantly higher than that in the group without H.pylori infection.Conclusion COX2 expression is involved in the carcinogenesis and malignant progression of gastric carcinoma.The examination of COX2 may be helpful to judge biological behavior of gastric carcinoma.