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Objective To establish an ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for detecting α-hydroxybutyrate (α-HB) in serum.Methods Electrospray ionization negative ion and multiple reaction monitoring mode were used to detect serum α-HB.The linearity,low limits of quantification,precision,recovery and interference of UHPLC-MS/MS were evaluated.The reference interval of this method was established in 130 serum samples (62 males and 68 females) from Shanghai East Hospital.Dixon method was used to judge the outliers and K-S test was used to analyze the data normality.The standard curve was scored by linear regression analysis.Results The total run time was 4 min of UHPLC-MS/MS method for the determination of α-HB.It has a good linear relationship in the range of 0.5-40.0 mg/L(r=0.999 4);the low limit of quantification was 0.5 mg/L;the in-batch and inter-batch coefficient of variation precision were less than 4.1％ and 6.3％,respectively;the recovery ranged between 95.8％ and 103.8％.Hemolytic samples (about 5 g/L hemoglobin),lipemic samples (about 12 mmol/L triglyceride),icteric samples (about 150 μmol/L total bilirubin) had no significant interference to the detection.The reference range of the apparent healthy population was 1.46-6.48 mg/L.Conclusions A method for the determination of serum α-HB by UHPLC-MS/MS was established.The method was simple,rapid,and could be used for the detection of clinical samples.
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Objective@#To establish a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the detection of serum oleic acid (OA), and preliminarily evaluate the role of OA in insulin resistance (IR) of type 2 diabetes (T2DM). @*Methods@#OA-［ 13 C 5 ］ was used as isotope-labeled internal standard, and the ion pairs of OA and OA-［ 13 C 5 ］ were 281.3/281.3 and 286.3/286.3, respectively. The ultrapure water was used as mobile phase A and methanol: acetonitrile (1∶1, v/v) as mobile phase B in a ZORBAX SB-Aq C18 reversed phase column. Meanwhile, the gradient elution system with a flow rate of 0.3 mL/min was used. According to the CLSI guidelines (EP15-A3), the reliability of the established method was evaluated by detecting the performance indicators such as precision, trueness, linear range, stability and carrying contamination rate. Serum OA levels were detected by the established HPLC-MS/MS method in 109 patients with clinically diagnosed T2DM and 100 healthy controls. The insulin resistance index (HOMA-IR) was calculated to evaluate IR, and the relationship between OA and IR was further analyzed. @*Results@#The established HPLC-MS/MS method for the detection of serum OA had good specificity and linearity in the range of 10-1 000 μmol/L (y=0.007 55x+0.004 83,r=0.997 7), and the low limit of quantification (LLOQ) was 10 μmol/L. It also had good precision, and the within-run coefficient of variation (CV) and total CV were not more than 1.62% and 1.73%, respectively, indicating that the method was suitable for the detection of serum OA. The serum OA levels in T2DM patients ［(425.58 ± 220.17) μmol/L］ were significantly higher than that in the healthy controls ［(113.20±58.00) μmol/L］, and serum OA levels were significantly correlated with HOMA-IR in T2DM patients and healthy controls. The area under the receiver operating characteristic (ROC) curve (AUC) of OA for the diagnosis of IR was 0.689. When the cut-off value identified by Youden index was 235.8 μmol/L, the sensitivity and specificity were 70.4% and 63%, respectively. When OA combined with fasting blood glucose (FBG) to diagnose IR, the AUC increased to 0.806, which was significantly higher than that of OA (P＜0.05). @*Conclusion@#A scientific and efficient HPLC-MS/MS method for the quantitative detection of serum OA is established successfully, which provides a reliable method for the dynamic monitoring of the changes of OA levels in the patients with metabolic diseases.
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Objective To investigate the distribution characteristics and drug resistance of pathogenic bacteria in ICU . Methods The bacteria identification and drug sensitive test were carried out on all pathogenic bacteria in ICU of our hospital from January 2013 to December 2013 .Results A total of 187 strains of pathogenic bacteria were separated ,among them 37 strains (19 .79% ) were Gram‐positive bacteria ,which was dominated by staphylococcus aureus ,with drug resistance rate to vancomycin , teicoplanin and linezolid of 0 .00% ;135 strains were Gram‐negative bacteria (72 .19% ) ,which was dominated by pseudomonas aeruginosa ,acinetobacter baumannii ,klebsiella pneumoniae and escherichia coli ,the drug resistant rate of acinetobacter baumannii to cefoperazone/sulbactam and minocycline was lower (43 .59% ,46 .15% ,which of pseudomonas aeruginosa to amikacin ,cefotaxime , cefoperazone/sulbactam were 27 .91% ,32 .56% and 30 .23% ,respectively ;15 strains(8 .02% ) of fungi were isolated ,which were mainly candida albicans and candida tropicalis .Conclusion Regular detection of distribution types and drug resistance change can provide the basis for climical rational use of antibacterial drugs .
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Objective To evaluate the effects of small interfering RNA (siRNA) against peptidylarginine deiminase 4 (PADI4) gene on apoptosis of fibroblast-like synoviocytes (FLS) from synovium of rheumatoid arthritis (RA).Methods The siRNA targeting PADI4 was constructed and transfected into FLS cells in RA via LipofectamineTM 2000.The expression level of PDAI4 mRNA was detected by using real-time quantitative polymerase chain reaction (real-time PCR).The protein expression of PADI4,CyclinB1 and P21 was detected by Western blotting.The apoptosis of FLS cells in RA was examined by flow cytometry.The levels of IL-1β were detected by ELISA.T-test was used for statistical analysis.Results siRNA-PADI4 efficiently down-regulated the PADI4 expression compared with control group,1.00±0.20 vs 0.38±0.20 (t=9.607,P＜0.01),0.39±0.23(t=8.394,P＜0.01).FCM analysis showed that the percentage of apoptosis cells in PADI4 siRNA group in FLS was (5.4±0.6)％ (t=-19.223,P＜0.01) and (6.1±0.6)％ respectively (t=-24.229,P＜0.01),which was significantly higher than that in the control group in FLS (1.6±0.3)％.The expression of CyclinB1 protein was decreased,and P21 increased.The concentrations of IL-1β in culture medium of the transfected group were (26.8±0.7) ng/ml (t=-10.747,P＜0.01) and (27.7±0.7) ng/ml (t=-10.967,P＜0.01),higher than the control group [(23.9±0.7) ng/ml].Conclusion After being transfected with PADI4 siRNA,the apoptosis of FLS cells in RA is increased.Our results have demonstrated the potential role of CyclinB1 and P21 in PADI4 signaling.
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Activating transcription factor 4 ( ATF4),one of the activating transcription factors,belongs to the cyclic AMP response element binding protein family.The expression of ATF4 is up-regulated by tumor micro-environmental factors.And ATF4 regulates the processes of tumor growth,infiltration,metastasis,apoptosis and drug resistance.Therefore,ATF4 might serve as a potential therapeutic target in cancer.
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AIM: To investigate the association between HBV infection and HLA-DPB1 gene in population of Guangzhou Chinese. METHODS: 58 unrelated patients (test positive of HbsAg,HBeAg,HbcAb) and 75 unrelated healthy control individuals were typed by sequencing based typing (SBT) method in their HLA-DPB1 gene. RESULTS: The phenotype frequencies of HLA-DPB1 alleles of patients and control have no significant difference. CONCLUSION: These results indicate that there is no association between HLA-DPB1 gene and HBV infection.