Determination of volatile nitrosamines in urine through gas chromatography-mass spectrometry / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a detection method based on gas chromatography-mass spectrometry (GC-MS) for concentrations of volatile nitrosamine compounds in urine, and apply it to the test of real samples.</p><p><b>METHODS</b>Target compounds dichloromethane in urine samples was extracted with dichloromethane through liquid-liquid extraction, then the dichloromethane extract was filtrated, evaporated with nitrogen at 40°C to dryness, and the volume was set with 0.2 ml dichloromethane. Analysis of nine volatile nitroso-compounds were performed with GC-MS under selected ion monitoring mode, external reference method was used for quantification, and the detection limit, repeatability and sensitivity were evaluated. In addition, nine volatile nitroso-compounds of 92 urine samples in a town of Anhui province were measured.</p><p><b>RESULTS</b>A good linear range of 2 - 200 ng/ml (with correlation coefficient 0.9985 - 0.9999) were obtained for the above mentioned nine kinds of analyte, and the lowest examination concentration was 0.05 - 0.50 ng/ml. The addition standard recoveries were 68%-102% with the RSD of 0.4% - 5.5% (n = 3). The detection limits were 0.001 - 0.013 ng/ml urine. The detection rate of N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopyrrolidine (NPYR), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitrosodi-n-butylamine (NDBA) and N-nitrosodiphenylamine (NDPhA) were 71% (65), 74% (68), 65% (60), 80% (73), 92% (85), 78% (72), 76% (70), 87% (80), 98% (90), respectively, with the results (0.27 ± 0.12), (0.75 ± 0.29), (0.06 ± 0.02), (0.16 ± 0.07), (23.66 ± 5.18), (1.01 ± 0.35), (0.38 ± 0.11), (2.47 ± 0.52) and (15.13 ± 3.48) nmol/g creatinine.</p><p><b>CONCLUSIONS</b>A gas chromatography-mass spectrometry detect method was developed for low level volatile nitrosamines in urine samples.</p>

Effects of triptolide on the production of interferon-gamma in human peripheral blood mononuclear cell and phosphorylation of signal transducer and activator of transcription-1 and production of interleukin-8 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effects of triptolide on the production of interferon-gamma (IFN-gamma) in human peripheral blood mononuclear cell (PBMC) and interleukin-8 (IL-8) in HaCaT keratinocytes and phosphorylation of signal transducer and activator of transcription-1 (STAT1) of IFN-gamma signal transduction pathways in HaCaT cells.</p><p><b>METHODS</b>Human PBMC was induced by phytohaemagglutinin (PHA-L) and HaCaT cells were stimulated by recombinant human IFN-gamma (rhIFN-gamma). The productions of IFN-gamma and IL-8 in cells were detected by ELISA. The expression of STAT1 and its phosphorylation were analyzed by Western blot.</p><p><b>RESULTS</b>Triptolide inhibited the production of IFN-gamma in human PBMC induced by PHA-L in a dose-dependent manner (P < 0.05, P < 0.01, P < 0.001) and the 50% inhibitory concentration (IC50) value was 5.96 x 10(-11) mol/L. IL-8 production in HaCaT cells induced by rhIFN-gamma in vitro was also inhibited by triptolide (P < 0.001) and the IC50 value was about 1.15 x 10(-13) mol/L. The expressions of phosphorylated STAT1 in HaCaT cells stimulated by rhIFN-gamma was inhibited by triptolide (P < 0.01) and the IC50 value was about 9.45 x 10(-11) mol/L.</p><p><b>CONCLUSION</b>Triptolide can inhibit the production of IFN-gamma in human PBMC and downregulate IL-8 level in HaCaT keratinocytes induced by rhIFN-gamma. Triptolide can inhibit the phosphorylations of STAT1 of IFN-gamma signal pathway in HaCaT keratinocytes stimulated by IFN-gamma.</p>

In vitro Antiviral activity of a berberine derivant HB-13 against herpes simplex virus / 中华皮肤科杂志

Objective To evaluate the in vitro antiviral activity of HB-13,a compound derivant from berberine and its prodrug berberine,against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). Methods Vero cells were cultured in vitro and infected with HSV.Then,various concentrations of HB-13, berberine,and aciclovir were used to treat these infected cells.The cytopathic effect was observed to deter- mine the antiviral effects and cytotoxicity of HB-13 and berberine.Results For HB-13,berberine and acy- clovir,the half toxicity concentration (TC_(50)) to Vero cells was 31.99,380 and more than 800?g/mL, respectively;the average half inhibitory concentration (IC_(50)) against HSV-1 was 1.328,more than 100,and 0.443?g/mL,respectively,the treatment index (TI) against HSV-1 was 24.09,less than 3.80,and more than 1805.87,respectively;the IC_(50) against HSV-2 was 1.344,more than 100,and 0.679?g/mL,respectively,the TI against HSV-2 was 23.80,less than 3.80 and more than 1178.20,respectively.Conclusion HB-13 possesses marked antiviral activity against HSV-1 and HSV-2 in vitro,while berberine does not.

Application of Cationic Liposome and Direct Injection Method to Express hGH in Mice in vivo / 中国肿瘤生物治疗杂志

An eukaryotic expression plasmid Rc/CMV GHcDNA containing CMV late promoter and hGH cDNA was constructed and introduced into mouse skeletal muscle by means of direct injection with or without the cationic liposome (Lipofectin and Lipofectamine reagent) intramuscularly. The expression of the gene was detected through both RT-PCR and IRMA (Immunoradiometric assay) at the level of transcription and protein respectively. The gene expression can be detected even after 90 days of single plasmid injection. Compared with the mice injected with the plasmid itself, the expression levels of mice injected with the plasmid-cationic liposome complex seem to be higher, and the expression period longer. Furthermore, the effect of Lipofectamine seems to be even better than that of Lipofectin. The results indicate that direct intramuscular injection with recombinant expression plasmid or plasmid-cationic liposome complex is a simple, efficient and economical way for foreign gene transfer and expression in experimental mice in vivo.