An investigation of the statistical power of the effect size in randomized controlled trials for the treatment of patients with type 2 diabetes mellitus using Chinese medicine / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate whether the power of the effect size was based on adequate sample size in randomized controlled trials (RCTs) for the treatment of patients with type 2 diabetes mellitus (T2DM) using Chinese medicine.</p><p><b>METHODS</b>China Knowledge Resource Integrated Database (CNKI), VIP Database for Chinese Technical Periodicals (VIP), Chinese Biomedical Database (CBM), and Wangfang Data were systematically recruited using terms like "Xiaoke" or diabetes, Chinese herbal medicine, patent medicine, traditional Chinese medicine, randomized, controlled, blinded, and placebo-controlled. Limitation was set on the intervention course > or = 3 months in order to identify the information of outcome assessement and the sample size. Data collection forms were made according to the checking lists found in the CONSORT statement. Independent double data extractions were performed on all included trials. The statistical power of the effects size for each RCT study was assessed using sample size calculation equations.</p><p><b>RESULTS</b>(1) A total of 207 RCTs were included, including 111 superiority trials and 96 non-inferiority trials. (2) Among the 111 superiority trials, fasting plasma glucose (FPG) and glycosylated hemoglobin HbA1c (HbA1c) outcome measure were reported in 9% and 12% of the RCTs respectively with the sample size > 150 in each trial. For the outcome of HbA1c, only 10% of the RCTs had more than 80% power. For FPG, 23% of the RCTs had more than 80% power. (3) In the 96 non-inferiority trials, the outcomes FPG and HbA1c were reported as 31% and 36% respectively. These RCTs had a samples size > 150. For HbA1c only 36% of the RCTs had more than 80% power. For FPG, only 27% of the studies had more than 80% power.</p><p><b>CONCLUSIONS</b>The sample size for statistical analysis was distressingly low and most RCTs did not achieve 80% power. In order to obtain a sufficient statistic power, it is recommended that clinical trials should establish clear research objective and hypothesis first, and choose scientific and evidence-based study design and outcome measurements. At the same time, calculate required sample size to ensure a precise research conclusion.</p>

Expertise-based randomized controlled trials and its application in acupuncture clinical research / 中国针灸

Through introduction of the methodological mechanism and comparison with classic randomized controlled trial, the status and the applicability of the expertise-based randomized controlled trials in clinic are explored, and its characteristics in acupuncture clinical application are analyzed. It is held that expertise-based randomized controlled trial is more suitable for the acupuncture clinical research, especially for acupuncture practice which emphasizes manipulations and different schools.

Secreted expression of Bacillus pumilus xylanase gene in Pichia pastoris and study on enzymatic properties / 生物工程学报

The endo-1,4-xylanase gene from Bacillus pumilus HB030 was cloned into the Pichia pastoris expression vector, pPIC9k, the recombinant plasmid was named pHBM220. The digested recombinant plasmid pHBM220 was transformed into Pichia pastoris KM71, GS115, SMD1168, respectively. The recombinant Pichia pastoris KM71 (pHBM220), GS115 (pHBM220), SMD1168 (pHBM220) secreted functional endo-1,4-xylanase, and the enzymatic activities reached 10.80IU/mL, 11.63IU/mL, 9.68IU/mL, respectively. The temperature and pH optimum for the recombinant xylanase were 60 degrees C and pH5.5, respectively.

Expression and identification of recombinant arresten in Pichia pastoris / 生物工程学报

Arresten as a endogenous inhibitor of angiogenesis originated from the carboxyl-terminal 223 amino acids fragment of the non-collagen domain in alpha1 chain of human collagen IV. In order to get the soluble arresten with biological activity, the cDNA of arresten was cloned and expressed in Pichia pastoris. The produced arresten cDNA was amplified by PCR using primer P1:5'-AGGCCCCGATGGGTTGC-3', primer P2:5'-CTATAAG GCACTTTACGGTTTC-3'. The PCR products was cloned into pGEM-T vector, and sequenced. The arresten cDNA from pGEM-T vector was recombined with vector pPIC9 as pPIC9-arresten, used to transform E. coli DH5alpha, and the inserted arresten cDNA confirmed by agarose electrophoresis and sequencing. pPIC9-arresten was linearized by Sac I. Pichia pastoris GS115 was treated with PEG1000 (followed Invitrogen' s specification); transformed with linear recombined pPIC9-arresten. Pichia pastoris GS115 was culured on MD mediun, single clone was selected and the DNA from the single clone was extracted, used as template, characterized by PCR using the second pair primers P3:5'-CGCTCGAGAAAAGATCTGTTGATC-3', P4:5'-GCCCCGG ATCCTTATGTTCTFCTCATACAG-3'. The polynucleotides CTCGAGAAAAGA used as marker sequence was inserted into primer P3 for signal peptidase to cleave off the signal sequence correctively. The recombined Pichia pastoris GS115 was selected according to the results of PCR, cultured on MM and MD media and then in the BMGY media using methanol as inducer. Expressed arresten was analysed by SDS-PAGE. The soluble arresten expressed by Pichia pastoris gave apparent molecular weight in SDS-PAGE consistent with that calculated, and in matrigel gel it showed inhibitary activity on the tubulation of endothelial cell ECV-304 induced by tumor cell MDA-MB-435S. These results showesd arresten with biological activity is expressed successfully in Pichia pastoris GS115.

Cloning of Acidic Xylanase Gene and Its Secretion Expression in Pichia pastoris / 微生物学通报

An acidic xylanase gene,named xyl3,was cloned from the genomic library of enviromental microbes constructed by using shotgun cloning strategy,and submitted to GeneBank with accession number of gb:AY300805.BLAST analysis indicated that the gene xyl3 has low similarity with other xylanase genes and the encoded xylanase,sorted as Glycosyl hydrolases family 10,has 77% similarity with the intra-cellular xylanase from Geobacillus stearothermophilus at amino acid level.Treated with T4 DNA polymerase,the gene xyl3 was ligated with the linearized Pichia pastoris expression vector pHBM905 produced by digestion of restriction endonuclease CpoI and NotI to generate the recombinant plasmid pHBM706.Then the plasmid pHBM706,digested by restriction endonuclease SalI,was transformed into P.pastoris GS115 to obtain the recombinant P.pastoris GS115(pHBM706),which was induced to produce the recombinant xylanase with 0.5% methanol at 28℃.At the 36th hours of induction,the porduced crude enzyme was detected to reach the higest enzyme activity of 0.177 IU/mL.The optimal pH and temperature of the enzyme activity is 5.5 and 50℃ respectively.