Objective To develop a polymerase chain reaction(PCR) assay for rapid,specific and sensitive detection of Shigella ipaH gene.Methods According to the sequences of the ipaH gene,primers were designed to amplify ipaH gene.The length of amplicon was 204 bp.To evaluate the specificity of the assay,3 strains of Shigella and 6 strains of non-Shigella were tested by PCR.One of Shigella flexneri was 10-fold serially diluted and amplified by PCR to verify the limit of detection.PCR results were judged by electrophoresis and DNA sequence analysis.Results For 3 strains of Shigella,the results of the PCR assay were observed.No amplified bands were observed in 6 strains of non-Shigella.The specificity of PCR assay was also confirmed by DNA sequence analysis.The detection limit of PCR assay was 10 CFU/ml of Shigella flexneri.Conclusions These results indicated that the PCR assay is a rapid,specific and sensitive detection method for Shigella ipaH gene.

Objective To study the pathophysiology of ankylosing spondylitis (AS)-related osteoporosis by investigating the relation between bone mineral density (BMD) and bone turnover markers.Methods Fortysix AS patients were included in this study,including 35 male and 11 female patients.Twenty-five gender and age matched healthy subjects were served as the healthy control group.Informed consents were obtained from all subjects.BMD of lumbar spine (L2-4),fermoral neck and radius were tested using dual-energy X-ray absorption method.Data about BASDAi,ESR,Ig was collected.Bone formation markers including procollagen type Ⅰ N-terminal peptide (PINP) and osteocalcin (OC) were included for analysis,the formal was measured by radioimmunoassay and the later was measured by immunoradiometric assay and bone resorption marker.β-Crosslaps was measured by electrochemiluminescence immunoassay.Independent-samples t test was used to compare normal distributed data between the two groups.Analysis of variance was used to compare the data between the three groups.For those data which were not normally distributed,Rank sum test was performed.Correlations were determined by Pearson or Spearman's ranking.Results ① 48％ of AS patients had bone loss,while the percentage in the healthy control group was 20％ (x2=5.32,P=0.021).BMD of lumbar spine,fermoral neck and radius of the AS patients were lower than the controls (t=-3.73,-3.68,-5.24; P＜0.05).② Bone density (BMD) of lumbar spine in patients at the late stage was higher than patients at early disease stage (t=2.26,P=0.034),however,the BMD in the femoral neck was not.③ The procollagen (PINP),OC and β-CrossLaps were not significantly different in patients at different stage of diseases (P＞0.05).④BMD of lumbar spine was negatively correlated with the β-CrossLaps and ESR(r=-0.325,P=0.047; r=-0.314,P=0.046),The BMD in fermoral neck was negatively correlated with β-CrossLaps and OC (r=-0.387,P=0.024; r=-0.371,P=0.034),but they were not correlated with disease duration and BADSAI.Conclusion Osteoporosis is common in AS.Bone turnover markers including bone formation and bone resorption are increased in AS.β-CrossLaps is likely to predict bone loss in AS.

A rapid detection method of 16 preservative residues in vegetables for export was developed by gas chromatography_mass spectrometry ( GC_MS ) after pre_treatment method of dispersive solid phase extraction ( SPE) . Samples including leafy, eggplant fruit, bean, melon and tuber vegetables were extracted with acetonitrile and detected by GC/MS with external standard method after being cleaned up with dispersive SPE. The results showed that the method had a good linearity over concentration range of 0 . 02-2 . 0 mg/L preservatives with correlation coefficients of 0 . 9990-0 . 9997 . The limits of detection ( LODs ) were in the range of 0. 004-0. 965 μg/kg. The recoveries of the preservatives were in the range of 76. 7%-120. 0% at the spiked levels of 0. 01, 0. 02 and 1. 00 mg/kg, and the relative standard deviations ( RSDs) were in the range of 2. 1%-10. 6%. Compared with the GB/T 19648_2006, etc, the method is rapid, simple, highly sensitive, and can meet testing requirements of 16 preservative residues in vegetables for export.

Objective To investigate the expression of micro RNA-146a (miR-146a),TNF receptorassociated factor 6 (TRAF6) gene and IL-1 receptor-associated kinase 1 (IRAK1) gene in the peripheral mononuclear cells (PBMCs) of patients with ankylosing spondylitis (AS) and their relationship with the disease activity.The role of miR-146a,TRAF6,IRAK1 in the pathogenesis of AS was explored.Methods Expression of miR-146a,TRAF-6 and IRAK-1 in peripheral blood mononuclear cells was studied using realtime polymerase chain reaction (qRT-PCR) in 45 AS patients and 22 healthy controls.The indicators of disease activity adopted in this study were Bath ankylosing spondylitis disease activity index (BASDAI),erythrocyte sedimentation rate (ESR),C-reactive protein (CRP) level,and immunoglobulin (Ig).The relationship was analyzed in AS patients between the relative expression levels miR-146a,TRAF6,IRAK1 and BASDAI,ESR,CRP,Ig concentration.Non-parametric test,t test,One-way ANOVA,Pearson's and Spearman's correlation analysis were used for statistical analysis.Results ①The relative expression level of miR-146a which was observed in PBMCs of AS patients was significantly higher than that in normal control group [1.46(0.39,4.79)and 0.81(0.17,1.90),P＜0.05].The expression of miR-146a was significantly higher in active AS patients group than that in inactive patients [2.93(0.95,7.95) and 0.54(0.28,1.69),P＜0.05],there was no difference between the treatment group and without treatment group [1.28(0.31,2.37) and 2.22(0.49,7.71),P＞0.05].② There was significant difference in the relative expression level of IRAK-1 between AS patients and the normal control group.IRAK1 was significantly higher in AS patients than that in normal control group (1.4±0.7,1.1±0.4,P＜0.05).However,there was not difference between active AS patients group and inactive patients group as well as treated group and untreated group (1.5±0.9,1.4±0.5; 1.6±0.7,1.3±0.7,P＞0.05).③ TRAF6 expression was obviously lower in AS patients than that in normal control group (1.3±0.6,1.7±0.8,P＜0.05),and that was also significantly lower in the untreated group and active group than that in the normal control group (1.1±0.7,1.7±0.8; 1.1±0.5,1.7±0.8,P＜0.05).④ Signi-ficant positive correlation was observed between the miR-146a level and BASDAI,as well as duration of morning stiffness (r=0.557,P=0.000; r=0.363,P=0.018).The expression level of IRAK1 was significantly negative correlated with IgM (r=-0.313,P=0.046).Conclusion ① miR-146a expression is up-regulated in patients with AS,and it may be a potential useful marker for disease activity in AS patients; ② The abnormal expression of IRAK1,TRAF6 in AS patients may play a role in the pathogenesis of AS.

Objective To assess the efficacy and safety of ipragliflozin ,a sodium glucose cotransporter 2 (SGLT2)inhibitor,for the treatment of type 2 diabetes. Methods Pubmed,the Cochrane Library,EMbase,CBM and CNKI databases was searched to identify randomized controlled trials(RCTs)pertinent to of ipragliflozin. The risk of bias of the included RCTs was assessed according to the Cochrane Handbook for Systematic Reviews of Inter-ventions Version 5.1.The RevMan 5.3 software was used for Meta-analysis. Results Ten RCTs with 2,390 partici-pants were included,Meta analysis showed that ipragliflozin was more effective than placebo in improving HbA1c level,and could concurrently reduce body weight,blood pressure,and the fasting plasma glucose(FPG)but not increase the risk of hypoglycemia. There were no statistically significant differences in the occurrence of urinary tract infection and genital infection as well as serious adverse events. Conclusion As a safe method ,ipragliflozin can effectively improve the HbA1c level in type 2 diabetes,help patients lose weight and reduce blood pressure.

Long-chain dicarboxylic acid (DCA), a building block for synthesizing a variety of high value-added chemicals, has been widely used in agriculture, chemical, and pharmaceutical industries. The global demand for DCA is increasing in recent years. Compared with chemical synthesis which requires harsh conditions and complicated processes, fermentative production of DCA has many unparalleled advantages, such as low cost and mild reaction conditions. In this review, we summarized the chemical and microbial synthesis methods for DCA and the commercialization status of the fermentation process. Moreover, the advances of using molecular and metabolic engineering to create high-yielding strains for efficient production of DCA were highlighted. Furthermore, the challenges remaining in the microbial fermentation process were also discussed. Finally, the perspectives for developing high titer DCA producing strains by synthetic biology were proposed.
Fermentation ; Dicarboxylic Acids/metabolism* ; Metabolic Engineering ; Technology