Aged ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Carcinoma, Signet Ring Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Gastrectomy ; methods ; Histiocytic Sarcoma ; metabolism ; pathology ; surgery ; Humans ; Lymphatic Metastasis ; Male ; Phosphoglucomutase ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; surgery

A rapid, sensitive and convenient LC-MS/MS method was developed for the determination of γ-aminobutyric acid (GABA) in human plasma. d2-γ-Aminobutyric acid (d2-GABA) was synthesized as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all analytes were separated on a Luna HILIC column (100 mm x 3.0 mm, 3 μm) using an isocratic mobile phase of water: acetonitrile: formic acid (20 : 80 : 0.12) with a flow rate of 0.5 mL x min(-1). Acquisition of mass spectrometric data was performed in multiple reaction monitoring mode (MRM) in positive electrospray ionization using the transitions of m/z 104 --> 69 for GABA and m/z 106 --> 71 for d2-GABA. The method was linear in the concentration range of 5.00 to 1 000 ng x mL(-1). The intra- and inter-day precisions were within 9.9%, and accuracy ranged from 99.1% to 104%, within the acceptable limit across all concentrations. The method was successfully applied to a pharmacokinetic study of GABA tablets in healthy Chinese volunteers.
Chromatography, Liquid ; Humans ; Tandem Mass Spectrometry ; gamma-Aminobutyric Acid ; blood

The study aims to develop a rapid, sensitive and specified method of liquid chromatography with heated electrospray ionization tandem mass spectrometry (LC-HESI/MS/MS) for simultaneous determination of amlodipine, benazepril and benazeprilat in human plasma using amlodipine-d4 and ubenimex as internal standards (ISs). Selected reaction monitoring (SRM) with heated electrospray ionization (HESI) was used in the positive mode for mass spectrometric detection. Analytes and ISs were extracted from plasma by simple protein precipitation. The reconstituted samples were chromatographed on a C18 (100 mm x 4.6 mm, 5 microm) column with mixture of methanol-acetonitrile-5 mmol.L- ammonium acetate-formic acid (30 : 30 : 40 : 0.1) as mobile phase at a flow rate of 0.6 mL.min-1. The standard curves were demonstrated to be linear in the range of 0.02 to 6.00 ng.mL-1 for amlodipine, 0.2 to 1,500 ng.mL-1 for benazepril and benazeprilat with r2>0.99 for each analyte. The lower limit of quantitation was identifiable and reproducible at 0.02, 0.2 and 0.2 ng mL-1 for amlodipine, benazepril and benazeprilat, respectively. The intra-day and inter-day precision and accuracy results were within the acceptable limit across all concentrations. The plasma samples were stable after four freeze-thaw cycles and being stored for 93 days at -20 degrees C. The method was applied to a pharmacokinetic study of a fixed-dose combination of amlodipine and benazepril on Chinese healthy volunteers.
Administration, Oral ; Amlodipine ; administration & dosage ; blood ; Benzazepines ; administration & dosage ; blood ; Chromatography, Liquid ; Humans ; Sensitivity and Specificity ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry

The study aims to evaluate the bioequivalence of valsartan hydrochlorothiazide tablets, and to investigate the potential cause of bioinequivalence. This was a single-center study with an open, randomized double-way crossover design. Test and reference preparations containing 160 mg of valsartan and 25 mg of hydrochlorothiazide were given to 36 healthy male volunteers. Plasma concentrations of valsartan and hydrochlorothiazide were determined simultaneously by LC-MS/MS. The pharmacokinetic parameters and relative bioavailability were calculated, while the bioequivalence between test and reference preparations were evaluated. The dissolution profiles of test and reference preparations in four different mediums were determined via dissolution test and HPLC. The similarity was investigated according to the similarity factors (f2). The F(o-t) and F(0-infinity) were (139.4 +/- 65.2)% and (137.5 +/- 61.2)% for valsartan of test preparations. It led to get the conclusion that test and reference preparations were not bioequivalent for valsartan. A significant difference was observed between test and reference tablets in the valsartan dissolution test of pH 1.2 hydrochloric acid solution. The key factor of the bioinequivalence might be that dissolution of valsartan in acid medium has marked difference between two preparations.
Administration, Oral ; Adolescent ; Adult ; Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Antihypertensive Agents ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Area Under Curve ; Chromatography, Liquid ; Cross-Over Studies ; Drug Liberation ; Humans ; Hydrochlorothiazide ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Male ; Tablets ; Tandem Mass Spectrometry ; Therapeutic Equivalency ; Valsartan ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Young Adult

To study the metabolite excretion of theophylline, a rapid and specific method by liquid chromatography with heated electrospray ionization tandem mass spectrometry (LC-HESI/MS/MS) method for simultaneous determination of theophylline, 1, 3-dimethyluric acid (1,3-DMU), 3-methylxanthine (3-MX) and 1-methyluric acid (1-MU) in human urine was developed using theophylline-d6 and 5-fluorouracil as internal standards. Selected reaction monitoring (SRM) with heated electrospray ionization (HESI) was used in the negative mode for mass spectrometric detection. After diluted with methanol and centrifuged, the analytes and ISs were separated on a XDB-Phenyl (150 mm x 4.6 mm, 5 microm) column with a mixture of water-methanol-formic acid (30 : 70 : 0.15) as mobile phase at a flow rate of 0.6 mL x min(-1). The linear calibration curves for theophylline, 1, 3-DMU, 3-MX and 1-MU were obtained in the concentration range of 1.0-250 microg x mL(-1), separately. The method herein described is effective and convenient, and can be used for determination of theophylline and its three metabolites. The results showed that urinary excretion ratio of theophylline, 1,3-DMU, 3-MX and 1-MU is approximately 1 : 3 : 1 : 2 in Chinese subjects, which is similar to the reported excretion pattern in Caucasian.
Administration, Oral ; Asian Continental Ancestry Group ; Calibration ; Chromatography, Liquid ; Delayed-Action Preparations ; metabolism ; Healthy Volunteers ; Humans ; Spectrometry, Mass, Electrospray Ionization ; Tablets ; Tandem Mass Spectrometry ; Theophylline ; metabolism ; urine ; Uric Acid ; analogs & derivatives ; urine ; Xanthines ; urine

lacZα-mini-attTn7 was inserted into the intergenic region between the gG and gD genes in a PRV bacterial artificial chromosome (BAC) by homologous recombination in E. coli. The resulting recombinant BAC (pBeckerZF1) was confirmed by PCR and sequencing. Green fluorescent protein (GFP) gene was then transposed into pBeckerZF1 by transposon Tn7 to generate pBeckerZF2. Recombinant viruses vBeckerZF1 and vBeckerZF2 were generated by transfection with the corresponding BAC pBeckerZF1 or pBeckerZF2. The titers and cytopathic effect (CPE) observed for by vBeckerZF1 and vBeckerZF2 was comparable to that of the parental virus vBecker3. vBeckerZF2 was serial passaged for five rounds in cell culture, and the mini-Tn7 insertion was stably maintained in viral genome. These results show that recombinant viruses can be rapidly and reliably created by Tn7-mediated transposition. This technology should accelerate greatly the pace at which recombinant PRV can be generated and, thus, facilitate the use of recombinant viruses for detailed mutagenic studies.

Objective To investigate the antibacterial effect of grape peel residue procyanidins on common clinical bacteria ,inclu‐ding E .coli ,Pseudomonas aeruginosa ,Acinetobacter baumannii ,Enterococcus and methicillin‐resistant Staphylococcus aureus (M R‐SA) .Methods By the means of agar plate method ,we detected the minimum inhibitory concentration (MIC) of 30 strains of E .co‐li ,28 strains of Pseudomonas aeruginosa ,15 strains of Acinetobacter baumannii ,32 strains of Feces Enterococcus ,25 strains of E . faecalis and 70 strains of MRSA ,then calculate the MIC50 and MIC90 .The result was analyzed with SPSS software 16 .0 .Results The concentration of procyanidins at 3 -8 mg/mL had no inhibitory effect on E .coli ,Pseudomonas aeruginosa and Acinetobacter baumannii;there was no inhibitory effect on E .faecalis at 3-8 mg/mL ,but the inhibition rate to Feces Enterococcus was 6 .3% .By measuring the inhibitory effect of procyanidins on 70 MRSA ,the inhibition rate at 4 mg/mL was 65 .7% ,at 8 mg/mL was 95 .7% , MIC50 was 4 .221 mg/mL and MIC90 was 6 .260 mg/mL .Conclusion There are no inhibitory effects of grape peel residue procya‐nidins on Gram‐negative bacilli such as E .coli ,Pseudomonas aeruginosa ,Acinetobacter baumannii ,and there are certain inhibitory effects on Gram‐positive bacteria such as MRSA ,enterococci ,especially on MRSA (P<0 .05) .

OBJECTIVETo study in series the p16 protein expression on the rat brain tumor induced transplacentally by ENU.

METHODSThe p16 protein expression was determined with immuno-histochemistry stain on the offspring's brain at their 60, 90, 120, 150 days after birth.

RESULTS(1) p16 proteins were expressed in all of the brain samples in the 60-day group; occasionally negative in the 90-day group; partly expressed in the 120-day group; significantly less expressed in the 150-day group. (2) The rate of expression in the tissue around tumor was higher than that in the tumor. (3) The p16 protein was mainly orientated in the nuclear of cell and sporadically orientated in the cytoplasm.

CONCLUSION(1) It shows the p16 protein expression decreases with the increase of tumor incidence in the rat brain, which accompanies the start and development of the induced tumor. So we speculate that the dysfunction of p16 gene is one of the factors related to tumor incidence in this animal model. (2) The p16 protein is mainly orientated in the nuclear of cell and sporadically orientated in the cytoplasm.

Animals ; Brain ; metabolism ; pathology ; Brain Neoplasms ; chemically induced ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p16 ; biosynthesis ; Disease Models, Animal ; Ethylnitrosourea ; Female ; Glioma ; chemically induced ; metabolism ; pathology ; Immunohistochemistry ; Male ; Placenta ; drug effects ; Pregnancy ; Rats ; Rats, Sprague-Dawley

The improvement of diagnostics teaching system,including the establishment of curriculum system and evaluation system,is the base of promoting clinical- medicine teaching.Our study showed that the theoretical knowledge and clinical skill of medical students could be improved by constructing clinical diagnostics curriculum system and improving organization management and assessment system,which could pave the way for the transition from medical students to clinicians.

Objective To investigate whether the release of fibroblast growth factor-1 ( FGF-1 ) was changed after inhibition of S100A13 gene (small hairpin RNA, shRNA)and serum-deprivation in human thyroid cancer cells (TT cells ). Methods The S100A13-shRNA pENTRTM/U6 entry vector was transfected into TT cells. The expression of S100A13 mRNA and protein was detected by immunoflurescence, real-time RT-PCR, and Western blot. Then TT cells were treated with S100A13 gene inhibition and serum-deprivation. The changes in release of FGF-1 were detected by indirect immunoflurescence, RT-PCR, and ELISA. Results S100A13 shRNA transfected TT cells (S100A13 RNAi cells)had a reduction of S100A13 gene and protein expression by 80%.Indirect immunofluorescence indicated FGF-1 was mostly localized in the cytoplasm and nucleus of TT cells in primary culture. When serum-deprivation stress was given to TT cells, FGF-1 in cytoplasm almost disappeared in the cells at 6 h. RT-PCR indicated that when serum-deprivation stress was given to TT cells the mRNA of FGF-1 was reduced. ELISA showed that with inhibition of S100A13, the release of FGF-1 was reduced (P＜0.05).Conclusion S100A13-shRNA pENTRTM/U6 entry vector transfected TT cells may inhibit the expression of S100A13 and reduce the release of FGF-1.