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<p><b>OBJECTIVE</b>A highly sensitive and rapid high-performance liquid chromatography method with pre-column derivatization with 4-fluoro-7-nitrobenzofurazan was developed for determination of taurine in biological samples, including plasma, brain, and liver.</p><p><b>METHODS</b>The optimum derivatization reaction temperature was 70 °C, and at this temperature the reaction was complete within 3 min. The derivatized taurine was separated using phosphate buffer (0.02 mol/L, pH 6.0):acetonitrile (84:16, v/v) as the mobile phase at a flow rate of 1.0 mL/min, and a column temperature of 25 °C. The taurine derivatives were separated within 20 min (tR:14.5 min) and fluorometrically detected at 530 nm with excitation at 470 nm.</p><p><b>RESULTS</b>The intra- and the inter-day coefficients of variation for the method were 5.3% and 7.7%, respectively. The calibration curve was linear from 0.1 μmol/L to 30.0 μmol/L with a correlation coefficient of 0.9995.</p><p><b>CONCLUSION</b>This method can be used to determine the taurine contents in plasma, brain, and liver from normal rats and human plasma.</p>
Subject(s)
Animals , Female , Humans , Male , Rats , 4-Chloro-7-nitrobenzofurazan , Chemistry , Acetonitriles , Chemistry , Brain Chemistry , Chromatography, High Pressure Liquid , Fluorescent Dyes , Chemistry , Hydrogen-Ion Concentration , Liver , Chemistry , Rats, Wistar , Solvents , Chemistry , Taurine , Blood , TemperatureABSTRACT
Objective To know the situation of HCH and DDT residues in the health foods in Shandong Province, China. Methods HCH and DDT residues in 102 different kinds of health food samples were determined by capillary gas chromatography in 2006. Results The detection rate of HCH was 100%, the eligible rate was 97%, as for DDT, they were 62.7% and 96.1% respectively. Conclusion The situation of organochlorine pesticide residues in the health foods in Shandong Province is not satisfactory and to ensure the quality of the health foods, a powerful supervision should be taken, the raw materials of the health foods should be natural and no pollution.
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0.999) and the limits of detection were 0.03-0.6 ng/ml. The average recoveries were 85.5%-113.1%, RSDs were 1.8%-4.6%. Conclusion With the accuracy, high sensitivity and reproducibility, the method is suitable for the determination of organochlorine pesticide residues in the honey.
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Objective To evaluate the correlation of intrahepatic HBV DNA load with the HBV load in serum and peripheral blood mononuclear cells(PBMC)and the stage of fibrosis,grade of inflammation,level of serum ALT and AST.Methods Liver specimens were taken from 50 patients by percutaneous needle biopsy and divided into two parts:one was processed for histological examination,and the other was used for molecular biology analyses.HBV DNA load was measured with fluorescent quantitative polymerase chain reaction(FQ-PCR).The data of serum level of ALT and AST were collected.Results A high correlation between intrahepatic HBV-DNA load and serum virus load was found(r=0.77977,P
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Objective To explore the role of Bcl-2 and Caspase-3 in modulating apoptosis of ER-negative breast cancer cells induced by tamoxifen. Methods ER-negative breast cancer cell lines MDA-MB-231 were treated with 10.0?M tamoxifen for 12, 24, 36,48, 60 hours. The rate of cell apoptosis with or without caspase-3 inhibitor Ac-DEVD-CHO, and protein expression of Bcl-2,Bax were determined by flow cytometry, and the activity of Caspase-3 was examined with fluorophotometry. Results The expression of Bcl-2 was down-regulated, the activity of Caspase-3 and the rate of cell apoptosis were increased by TAM time-dependently, and the rate of apoptosis reached its peak at 48 hours. The expression of Bcl-2 was (negatively) correlated with activity of caspase-3. Tamoxifen, however, did not affect Bax protein expression. Ac-DEVD-CHO, a caspase-3 inhibitor, blocked the activation of caspase-3 and inhibited cell apoptosis (induced) by tamoxifen. Conclusions TAM could induce apoptosis in ER-negative breast cancer cells via (mitochondria) pathway by down-regulating Bcl-2 expression, and the activation of Caspase-3 might play an (important) role in the process of tamoxifen-induced apoptosis of ER-negative breast cancer cells.
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0.05). Conclusion: This method is simple, accurate, feasible for determination of reduced and total VC of beverage.