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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.
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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.
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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.
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OBJECTIVE:To establish derivative spectrophotometry for the determination of the main component of Captopril tablets.METHODS:Under the alkaline condition of sodium hydroxide,2,4-dinitrofluorobenzene was used as derivatization reagent to react with captopril at 40 ℃ in the water bath.Then UV spectrophotometry was adopted to detect the content of captopril with detection wavelength set at 342 nm.RESULTS:The linear range of captopril was 1.0～14.0 ?g?mL-1(r=0.999 9) with an average recovery of 99.61%(RSD=1.27%,n=9).The RSD of intra-day and inter-day both were less than 2%.CONCLUSION:This method is stable,reliable,rapid and simple for the determination of the main components of Captopril tablets.