Effect of Pirin on the proliferation and self-renew of glioma stem cell / 国际药学研究杂志

Objective To study the effect of Pirin(an iron-binding nuclear protein)on the proliferation and self-renewal of glioma stem cell(GSC)so as to provide a potential therapy target for malignant glioma.Methods PLKO.1-shPirin lentiviral plasmids were constructed to stably knock down Pirin in GSC by using lentivirus infection system.The interference efficiency of Pirin short hair?pin RNA(shRNA)was detected by Western blotting. The capacity of GSC was examined by the assessment of cell viability. Tumor sphere formation assay was used to detect the effect of Pirin on GSC self-renewal capacity. Results Pirin was highly expressed in GSC.Consistently,the protein level of Pirin in the conditioned medium from GSC was much higher than that from the corresponding non-stem tumor cell(NSTC).Gene-sequencing analysis demonstrated that PLKO.1-shPirin lentiviral plasmids were successfully con?structed.Pirin shRNA transfection significantly inhibited the expression of Pirin in GSC and suppressed the cell viability and ability of tumorsphere formation.Conclusion Knocking down Pirin significantly inhibites the cell proliferation and self-renewal of GSC.

LC-MS/MS determination of budesonide in dog plasma / 药学学报

A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of budesonide in dog plasma. Budesonide and the internal standard triamcinolone acetonide were separated from plasma by alkalinized liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a Capcell Pak C18 MG column with the mobile phase consisted of acetonitrile -5 mmol x L(-1) ammonium acetate (60:40, v/v) at a flow-rate of 0.50 mL x min(-1). A tandem mass spectrometer equipped with electrospray ionization source was used as detector and operated in the negative ion mode. Quantification was performed using multiple reaction monitoring (MRM) of the transitions m/z 489 --> m/z 357 and m/z 493 --> m/z 413 for budesonide and the internal standard, respectively. The linear calibration curves were obtained in the concentration range of 25.0-2000 pg x mL(-1). The lower limit of quantification was 25.0 pg x mL(-1). The intra- and inter-day relative standard deviation over the entire concentration range was less than 15%. The accuracy was in the range of -8.1% to -1.7% in terms of relative error. The method was applied to a pharmacokinetic study of budesonide controlled-release capsules in Beagle dogs. Maximal budesonide plasma level was observed after (3.5 +/- 3.3) h and the Cmax was (786 +/- 498) pg x mL(-1) after a single oral administration of 9 mg budesonide capsules, Cmax was increased to (2142 +/- 1515) pg x mL(-1) after multiple oral administration (9 mg x 5 d) of budesonide capsules. This method was selective and rapid, and the sensitivity was sufficient for the purpose of the pharmacokinetic study of budesonide controlled-release formulation.

Simultaneous determination of ephedrine and chlorpheniramine in human plasma by a highly sensitive liquid chromatography-tandem mass spectrometric method / 药学学报

<p><b>AIM</b>To develop and validate a liquid chromatography-tandem mass spectrometric (LC/MS/MS) method for the simultaneous quantification of ephedrine and chlorpheniramine in human plasma after oral administration of a compound preparation.</p><p><b>METHODS</b>The analytes and the internal standard, diphenhydramine, were isolated from plasma by protein precipitation with methanol, then chromatographied on a Zorbax SB-C18 column (150 mm x 4.6 mm ID) using a mobile phase consisted of methanol-water-formic acid (80: 20: 0.5, v/v), at a flow rate of 0.5 mL x min(-1). A tandem mass spectrometer equipped with electrospray ionization source was used as detector and was operated in the positive ion mode. Selected reaction monitoring (SRM) using the precursor to produce ion combinations of m/z 166-->115, m/z 275-->230 and m/z 256-->167 were used to quantify ephedrine, chlorpheniramine and the internal standard, respectively. Results The linear concentration ranges of the calibration curves for ephedrine and chlorpheniramine were 0.50 - 200 microg x L(-1) and 0.050 - 20.0 microg x L(-1), respectively. The lower limits of quantification were 0. 50 microg x L(-1) for ephedrine and 0.050 microg x L(-1) for chlorpheniramine, individually. The intra- and inter-day relative standard deviation (RSD) across three validation runs over the entire concentration range was less than 9.3% for both ephedrine and chlorpheniramine. The inter-day accuracy (RE) was within +/- 3.4% for the analytes. Each sample was chromatographied within 3.3 min. The method was successfully used in pharmacokinetics study of ephedrine and chlorpheniramine in human plasma after oral administration of a compound preparation containing 5 mg ephedrine hydrochloride, 1 mg chlorpheniramine maleate, 50 mg phenytoin, 12.5 mg theophylline, 12.5 mg theobromine and 7.5 mg caffeine. No interaction among the six components was observed on their pharmacokinetic parameters.</p><p><b>CONCLUSION</b>The method was proved to be highly sensitive, selective, and suitable for pharmacokinetics investigations of different compound preparations containing low dosage of both ephedrine and chlorpheniramine.</p>

Determination of risperidone in human plasma by liquid chromatography-tandem mass spectrometry / 药学学报

<p><b>AIM</b>To develop and validate a liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for the determination of risperidone in human plasma.</p><p><b>METHODS</b>Risperidone and the internal standard, diphenhydramine, were isolated from plasma by liquid-liquid extraction with etherdichloromethane (3:2, v/v) , then chromatographed on a Zorbax Extend-C18 column (150 mm x 4.6 mm ID, 5 microm) using a mobile phase consisted of acetonitrile-water-formic acid (40:60: 0.5, v/v), at a flow rate of 0.7 mL x min(-1). A Finnigan TSQ tandem mass spectrometer equipped with atmospheric pressure chemical ionization source was used as detector and was operated in the positive ion mode. Selected reaction monitoring (SRM) using the precursor product ion combinations of m/z 411-->191 and m/z 256-->167 were used to quantify risperidone and diphenhydramine (IS) , respectively.</p><p><b>RESULTS</b>The linear concentration range of the calibration curve for risperidone was 0.025 - 50 microg L(-1). The lower limit of quantification was 0.025 microg x L(-1). The intra- and inter-day relative standard deviation (RSD) across three validation running over the entire concentration range was less than 7.1%. The accuracy was within +/- 3.8%. Each sample was chromatographed within 2.7 min.</p><p><b>CONCLUSION</b>The method was proved to be rapid, sensitive and suitable for pharmacokinetic investigations of risperidone.</p>