To search the statistical approaches for evaluating and dealing with the center effects in multi-center clinical trial. Breslow-Day test was used for evaluating the differences of the virtual rating among the centers whose responses were binary, Cochran-Mantel-Haenszel test for dealing with the center effects whose responses were binary or ordinal, and logistic regression for evaluating and dealing with the center effects simultaneously. The results showed that Breslow-Day test is invalid in evaluating the center effects whose response is ordinal, and Cochran-Mantel- Haenszel test can not be used for dealing with the effects of other covariates meanwhile.

AIM: To investigate the effects of oxidized low density lipoprotein (OX-LDL) on expression of matrix metalloproteinase-2 (MMP-2) in human umbilical vein endothelial cells (HUVEC). METHODS: The MMP-2 mRNA was determined by reverse transcriptase-polymerase chain reaction (RT-PCR), MMP-2 protein was measured by western blotting and MMP-2 activity in conditioned medium was observed by gelatin zymography. RESULTS: In comparison with the control, there was no difference in the expression of MMP-2 between control and 25 mg/L LDL, whereas 25 mg/L OX-LDL increased MMP-2 activity in HUVEC ( P

A perfect clinical trial must nave a solid study design, strict conduction, complete quality control, non-interference of statistical result, and acceptable risk-benefit ratio. To reach the target, the quality control (QC) should be performed from the study design to conduction, from the analysis to conclusion. We discuss the relationship between data management and biostatistics from the statistical point of view, and emphasize the importance of the statistical concept and methods in the improvement of data quality in clinical data management.
Biostatistics ; Clinical Trials as Topic ; statistics & numerical data ; Data Collection ; standards ; Quality Control ; Research Design ; standards

Breast Neoplasms ; metabolism ; pathology ; Female ; Humans ; Insulin-Like Growth Factor Binding Protein 5 ; biosynthesis ; genetics ; Lymph Nodes ; pathology ; Lymphatic Metastasis ; RNA, Messenger ; biosynthesis ; genetics ; Tumor Cells, Cultured

In recent years, the medical graduates who take part in postgraduate examination have been increasing each year. The preparation for postgraduate examination affects the clinical practice, but not yet has a quantitative report. This article studied the students in general surgery, which were divided into postgraduate examination group and clinical practice group. By comparing the theoretical knowledge results and the clinical practice skills between the two groups we found that there was no difference between the two groups in the theoretical and operating skill when they were just in the department, and the operating results in the clinical practice group were better than the postgraduate examination group when they were out of the department.

It is difficult to measure the circular arc radius for central angle less than 30 degrees. The existing measuring methods are of low efficiency and big error. Through designing the machine vision system and studying the image detecting method for measurement, It is obtained good results by using the new measurement for tracheal intubation's circular arc radius, Realized a rapid and accurate measurement of the circular arc radius, and expanded the application in the field of machine vision.
Humans ; Imaging, Three-Dimensional ; instrumentation ; Intubation ; Trachea

Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Pneumoconiosis ; diagnostic imaging ; Radiography, Thoracic ; methods ; Tomography, X-Ray Computed

A perfect clinical trial must nave a solid study design, strict conduction, complete quality control, non-interference of statistical result, and acceptable risk-benefit ratio. To reach the target, the quality control (QC) should be performed from the study design to conduction, from the analysis to conclusion. We discuss the relationship between data management and biostatistics from the statistical point of view, and emphasize the importance of the statistical concept and methods in the improvement of data quality in clinical data management.

AIM:To introduce and evaluate two methods for sample size calculation in doseresponse research.METHODS:The methods used for sample size calculation in dose-response research include Cochran-Armitage trend(CAT) test proposed by Jun-mo Nam and the Unified contrast(CUC) method proposed by Chang. This paper takes the example of binary data,uses the two methods to calculate the required sample size and evaluate the power by simulation under the assumption that the response rate had a linear relationship with dosage under the logit scale.RESULTS:When the probability of response followed a linear trend on the logit scale, the sample sizes estimated from the two methods are approximately equal in various parameter's settings.The simulated power of CAT test was close to the expected one,however,the simulated power of CUC method was obviously affected by the values of contrast coefficient,if a contrast whose coefficients parallel the expected response, the CUC method was more powerful. CONCLUSION:When the probability of response follows a linear trend over dosage on the logit scale,the two methods reach almost the same result,in such circumstance,the Chang's unified contrast method will obtain an increasing power.

AIM:To introduce the concept of bridging study and its strategies in clinical trials for new drug application.METHODS:The concept of bridging study proposed in the ICH E5 guideline was introduced,with a case using bridging strategies in the new drug applications(NDAs)approved by the regulatory authority in Japan.The concrete mode and the development of bridging studies in Asia were summarized.RESULTS:With the application of the ICH E5,some countries and regions have successfully used the bridging strategy in the new drug applications.The bridging strategy is becoming a common and practical basis for the decision making of marketing approvals of new drugs in the Asia-pacific country.CONCLUSION:The currently bridging studies in Asia will play an important role in the extrapolation of foreign clinical data in new drug application.Using bridging study is very helpful in judging ethnic differences of drugs,reducing duplication of clinical trails,as well as shortening clinical development periods.