A liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying ilaprazole and its major metabolite in human plasma was developed and validated. Sample preparation was based on chloroform extractio...A liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying ilaprazole and its major metabolite in human plasma was developed and validated. Sample preparation was based on chloroform extraction. Chromatography was performed on a C18 analytical column and the retention times were 1.2, 1.28 and 1.65 min for ilaprazole, ilaprazole sulfone and omeprazole (internal standard), respectively. The ionization was optimized using ESI (+) and enhanced selectivity achieved by tandem mass spectrometric analysis. The calibration curve ranged from 0.36 to 368.40 ng/mL and from 0.125 to 128.000 ng/mL for ilaprazole and ilaprazole sulfone, respectively. The intra-and inter-day precision (CV) were within 15%, and accuracy of ilaprazole and ilaprazole sulfone were within 80% to 120%. The analytes showed stable over the timescale of the whole procedure. The robustness of the method was demonstrated by good reproducibility of results obtained from the analysis of clinical samples.展开更多
AIM: Caffeine metabolite ratios in urine can be used to evaluate the activity of CYP1A2, CYP2A6, NAT2 and XO in vivo. In this study, an HPLC method was developed to quantify the concentrations of caffeine metabolites ...AIM: Caffeine metabolite ratios in urine can be used to evaluate the activity of CYP1A2, CYP2A6, NAT2 and XO in vivo. In this study, an HPLC method was developed to quantify the concentrations of caffeine metabolites in 24 Chinese healthy volunteers. METHODS: 100 mg of caffeine was given to each subject as a probe drug and the urine samples of 0-12 h were collected. Urine samples were extracted with chloroform/isopropanol (9∶1, v/v) under acerbic environment (pH 3.5) and separated on a Hypersil BDS C18 column with gradient elution. The mobile phase was composed of phase A (acetonitrile) and phase B (10 mmol/L ammonium formate/formic acid (998/2, v/v) (pH 3.5) from 98/2 to 70/30, the detection wave length was 280 nm. CYP1A2 phenotype was calculated from the metabolite ratio of (AFMU+1X+1U)/17U, CYP2A6 from the ratio of 17U/(17U+17X+1U+1X+AFMU), NAT2 from the ratio of AFMU/(AFMU+1U+1X) and XO from the ratio of 1U/1X+1U. RESULTS: The calibration curves of AFMU, 1U, 1X, 17U, 17X, 137X were linear over the range of 1.25-160 μmol/L, yielding correlation of coefficients from 0.991 to 0.999. The LOD were 2.5 ng/mL for AFMU, 1X, 1U and 1 ng/mL for 17U, 17X, 137X. Recoveries for the analytes wereranged from 81%-94%, Intra-and Inter-day coefficients of variation were ranged from 2.56%-9.48% and 5.74%-10.91%, respectively. After logarithmic transformation of these metabolite ratios, phenotype of CYP1A2, CYP2A6, NAT2 were shown normal distribution, while the phenotype of XO was shown non-normal distribution with two subjects appearing with very low metabolic capacity. It was also found a negative association between the phenotype of CYP2A6 and CYP1A2 which might be explained by the fact that CYP2A6 plays an influential role in 17X metabolism. CONCLUSION: In brief, the experiment demonstrates an accurate, stable and replicable HPLC method for phenotyping of these enzymes in Chinese volunteers.展开更多
AIM: This study is aimed to investigate Runx2’s regulation by phytoestrogens resveratrol and genistein, screen for Runx2 mutation in Chinese cleidocranial dysplasia(CCD) patients, also determine the functional differ...AIM: This study is aimed to investigate Runx2’s regulation by phytoestrogens resveratrol and genistein, screen for Runx2 mutation in Chinese cleidocranial dysplasia(CCD) patients, also determine the functional difference between Runx2’s two major isoforms-type I and type II. METHODS: The simian virus 40 large T antigens (SV40LT) gene was used to establish immortalized hBMSCs and the cell line were then identified by specific surface markers confirmation and pro-longed life span and renewable proliferative capacity illustration. Then we tested resveratrol and genistein’s regulation on the cell line by monitoring several osteoblastic markers and invested the possible involved pathway by western blotting. Subsequently, we determined the functional difference of Runx2’s two major isoforms-type I and type II-in osteoblastic differentiation by RNAi. Also for the first time we screened for the Runx2 mutations in Chinese CCD patients by DNA analysis. RESULTS: We successfully established a permanent hBMSCs by stable transfection of SV40LT. Based on this cell line platform, we illustrated that phytoestrogens resveratrol and genistein regulated Runx2’s expression in osteoblastic differentiation and might partly via MAPK pathway. We also found that type I and type II play a different role in osteoblastic differentiation process, during which type I major increased in the early phase and important for the cell proliferation while type II predominantly functioned in the late stage and necessary for the cell maturation. What’s more, we sequencing coding domains and promoter domains of Runx2 from 9 patients in 3 different CCD familial cases and found two nucleotide changes. CONCLUSION: In this paper, we set up an immortalized hBMSC line by stable transfection of SV40LT which brings convenience for the later studies, reveals that resveratrol and genistein are capable of promote osteoblastic differentiation and are probably via MAPK pathway, also finds that type I major functions in the early stage of osteoblastic differentiation while type II predominantly functions in the late stage, which for the first time distinguishes their effects and gave new hints for bone-related diseases therapies. Moreover, the investigation on RUNX2 mutations in CCD patients adds new records to the repertoire of RUNX2 mutations in China.展开更多
AIM: Itopride, which is a dopamine D2 antagonist with acetylcholinesterase inhibitory actions, is often prescribed for patients with functional dyspepsia. The primary metabolite in humans is the N-oxide, generated by ...AIM: Itopride, which is a dopamine D2 antagonist with acetylcholinesterase inhibitory actions, is often prescribed for patients with functional dyspepsia. The primary metabolite in humans is the N-oxide, generated by oxidation of the tertiary amine N-dimethyl group. The urinary excretions of itopride and its N-oxide were 3.7% and 75.4%, respectively, in healthy subjects after a single oral administration at a therapeutic dose. Studies support a predominant role of FMO3 in the formation of itopride N-oxide in human liver microsomes. In addition, itopride appears to be a suitable probe for human liver FMO3. Our aim was to establish a simple method adopting a one-step liquid-liquid extraction with dichloromethane followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection to simultaneously determine itopride and its N-oxide in human plasma and urine for FMO3 pharmacogenetics study, using sulpiride as an internal standard (IS). METHODS: Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 360.1>166.4 for itopride, m/z 376.1>165.5 for itopride N-oxide and m/z 342.9>112.2 for IS, respectively. Analytes were chromatographed on an Intersil ODS-3 reverse-phase chromatographic column (2.1 mm×150 mm, 5 μm) by isocratic elution with water (1000 mL water added 1 mL formic acid)-acetonitrile (60∶40, v/v), the flow rate was 0.2 mL/min with a total analysis time of 3 min per run. RESULTS: The linearity for itopride and its N-oxide were in the range of 0.25-1 000 ng/mL and 0.5-1 000 ng/mL, respectively, both in plasma and urine (r2=0.999). The recovery of itopride was 95.8% for plasma and 101.2% for urine and that of itopride N-oxide was 90.4% for plasma and 98.4% for urine. The intra-and inter-day RSD were <15% both in plasma and urine. CONCLUSION: The method described is successfully applied to the analysis of itopride and its N-oxide in plasma and urine samples generated after administration of 50 mg itopride hydrochloride in 18 healthy male volunteers who were genetyped according to FMO3 genetic polymorphism.展开更多
AIM: The inhibition of organic anion transporting polypeptide 1B1 (OATP1B1) on the pharmacokinetics of rosuvastatin is unknown. Hence, the effect of ursodeoxycholic acid (UDCA) on the kinetics of rosuvastatin in healt...AIM: The inhibition of organic anion transporting polypeptide 1B1 (OATP1B1) on the pharmacokinetics of rosuvastatin is unknown. Hence, the effect of ursodeoxycholic acid (UDCA) on the kinetics of rosuvastatin in healthy volunteers is to be investigated. METHODS: The inhibition effect of long term use of UDCA on rosuvastatin kinetics was studied in 12 subjects in a randomized, crossover study. Each subject received 500 mg UDCA once daily continuously for 14 days. A single oral dose of 20 mg rosuvastatin was given on study day 15 and 34 separated by 2 weeks. Plasma concentrations of rosuvastatin were above the limits of quantitation for up to 72 h after dosing. RESULTS: UDCA significantly increased AUC0-72 and AUC0-∞ of rosuvastatin to 146%±55% (P=0.008) and 167%±73% (P=0.004) compared with those of the control group and CL/F decreased 75%±19% (P=0.003). The results confirmed the in vitro study that UDCA inhibited OATP1B1 activity via hepatic nuclear factor 1a (HNF1a). CONCLUSION: Inhibition of HNF1a and hepatic uptake may have consequences on clinic outcomes of drugs like rosuvastatin mainly excreted by hepatobiliary system.展开更多
Rifampin, a member of the rifamycin class of antibiotics, is well known for its ability to activate the pregnant X receptor and induce drug-metabolizing enzymes and transporters. Available data suggest rifampin entry ...Rifampin, a member of the rifamycin class of antibiotics, is well known for its ability to activate the pregnant X receptor and induce drug-metabolizing enzymes and transporters. Available data suggest rifampin entry into hepatocytes is mediated by OATP1B1. Accordingly, it is therefore plausible that modulation of the intracellular concentration of rifampin by OATP1B1 genetic polymorphisms would influence the degree of CYP3A induction. AIM: To study the association between haplotypes of the SLCO1B1 and the rifampicin-mediated inducible CYP3A4 activity. A single-point determination of midazolam plasma concentration method was developed to assess the constitutive and inducible CYP3A4 activity. A pharmacokinetic study of a single dose of 450 mg rifampicin was conducted to evaluate the mechanism of rifampicin-midazolam interaction in different SLCO1B1 genotypic subjects. METHODS: Twenty-three healthy volunteers with different SLCO1B1 haplotypes (7 for SLCO1B1*1a/*1a, 7 for SLCO1B1*1b/*1b, 7 for SLCO1B1*1b/*15 and 2 for SLCO1B1*15/*15) were enrolled in this study. Each was given a single oral dose of 7.5 mg midazolam on day 0 and day 6. Rifampicin of 450 mg was given from day 1 to day 5. Plasma concentrations of midazolam were measured for up to 8 hours by LC-MS, and its pharmacokinetic parameters were analyzed. Plasma concentrations of a single oral dose of 450 mg rifampicin were measured for up to 12 hours. RESULTS: A significant correlation (r2=0.763, P<0.001, n=23) was found between AUC(0-∞) and the single plasma concentration of midazolam at 2.5 hour (C2.5 h). The 2.5 h midazolam measurement was an optimal predictor of CYP3A phenotype. However, the percentage reduction of AUC(0-∞) or C2.5 h in different SLCO1B1 haplotypes was not significantly different. The pharmacokinetics parameters of rifampin were not significantly different between the 521T>C mutant group and the control group. CONCLUSION: A single blood concentration at 2.5 h after 7.5 mg oral midazolam intake can be used to predict CYP3A activity. The SLCO1B1 haplotypes do not influence the extent of inducible CYP3A activity by rifampin. SLCO1B1 genotypes has no significant impact on the disposition of rifampin in vivo.展开更多
AIM: To develop and validate a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying trimetazidine in human plasma. METHODS: Sample preparation was based on extracted using acetonitrile onl...AIM: To develop and validate a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying trimetazidine in human plasma. METHODS: Sample preparation was based on extracted using acetonitrile only. Chromatography was performed on a C18 analytical column and the retention times were 1.9 and 2.6 min for trimetazidine and cetirizine (internal standard), respectively. The ionization was optimized using ESI (+) and enhanced selectivity was achieved using tandem mass spectrometric analysis via two MRM functions, m/z:267→m/z:181 and m/z:389→m/z:201 for trimetazidine and cetirizine. RESULTS: The calibration curve ranged from 0.77 to 198 ng/mL. The inter-day precision and accuracy and the relative standard deviation (RSD) were<15%. The analyte was shown to be stable over the timescale of the whole procedure. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples. CONCLUSION: The experiment demonstrates an accurate, stable and reproducible LC-MS/MS method for quantifying trimetazidine in human plasma.展开更多
AIM: To evaluate the expression of eukaryotic initiation factors 3(eIF3) subunit 170 (eIF3 P170) in lung cancer tissues and its association with chemotherapy response of lung cancer. METHODS: 31 paraffin imbedded slic...AIM: To evaluate the expression of eukaryotic initiation factors 3(eIF3) subunit 170 (eIF3 P170) in lung cancer tissues and its association with chemotherapy response of lung cancer. METHODS: 31 paraffin imbedded slices of lung cancer tissue from fiberscope diagnosis, 20 samples of benign lung tissues from inflammatory pseudotumor and bronchiectasis, and 10 samples of normal lung tissues from surgical operation were collected. The protein expression of eIF3 p170 in lung-cancer tissues, benign lesion tissues, and normal lung tissues were determined by immunohistochemical staining. RESULTS: The positive ratio of eIF3 p170 expression in lung cancer tissues is higher than those in normal and benign tissues, the lung cancer patients with a higher expression level of eIF3 p170 seems to be more sensitive to chemotherapy. Here, we also found that down-regulation of expression of eIF3 p170 could inhibit the growth of human lung adeno-carcinoma cell A549 cells and decrease the sensitivity of A549 to cisplatin. CONCLUSION: Our data suggest that eIF3 p170 may be involved in the pathogenesis of lung cancer and it appears to be associated with chemotherapy response of lung cancer.展开更多
AIM: To determine whether the use of an antioxidant reagent coenzyme Q10 can protect human dopaminergic cell line SHSY-5Y against rotenone-induced apoptosis. METHODS: Cell viability was quantified by 3-(4,5-dimethylth...AIM: To determine whether the use of an antioxidant reagent coenzyme Q10 can protect human dopaminergic cell line SHSY-5Y against rotenone-induced apoptosis. METHODS: Cell viability was quantified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the apoptosis induced by rotenone was observed by Hoechst 33342, propidium iodide, and calcein AM staining in SHSY-5Y cells. RESULTS: Rotenone, a commonly used natural pesticide, inhibitor of mitochondrial respiratory chain complex I, was shown to decrease cell viability and induce apoptosis in SHSY-5Y cells. Pretreated with coenzyme Q10, the electron transporter in the mitochondrial respiratory chain, remarkably increased cell viability as well as significantly reduced the percentage of apoptotic SHSY5Y cells induced by rotenone. CONCLUSION: Coenzyme Q10 has a beneficial effect in protecting against rotenone-induced apoptosis in SHSY-5Y cells. The results support the hypothesis that coenzyme Q10 is a component of the antioxidant machinery that protects cell membranes from oxidative damage and decreases apoptosis. Further evaluation is required to determine whether the neuroprotective action of coenzyme Q10 can be used for the prevention and therapy of neurodegenerative diseases.展开更多
文摘A liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying ilaprazole and its major metabolite in human plasma was developed and validated. Sample preparation was based on chloroform extraction. Chromatography was performed on a C18 analytical column and the retention times were 1.2, 1.28 and 1.65 min for ilaprazole, ilaprazole sulfone and omeprazole (internal standard), respectively. The ionization was optimized using ESI (+) and enhanced selectivity achieved by tandem mass spectrometric analysis. The calibration curve ranged from 0.36 to 368.40 ng/mL and from 0.125 to 128.000 ng/mL for ilaprazole and ilaprazole sulfone, respectively. The intra-and inter-day precision (CV) were within 15%, and accuracy of ilaprazole and ilaprazole sulfone were within 80% to 120%. The analytes showed stable over the timescale of the whole procedure. The robustness of the method was demonstrated by good reproducibility of results obtained from the analysis of clinical samples.
文摘AIM: Caffeine metabolite ratios in urine can be used to evaluate the activity of CYP1A2, CYP2A6, NAT2 and XO in vivo. In this study, an HPLC method was developed to quantify the concentrations of caffeine metabolites in 24 Chinese healthy volunteers. METHODS: 100 mg of caffeine was given to each subject as a probe drug and the urine samples of 0-12 h were collected. Urine samples were extracted with chloroform/isopropanol (9∶1, v/v) under acerbic environment (pH 3.5) and separated on a Hypersil BDS C18 column with gradient elution. The mobile phase was composed of phase A (acetonitrile) and phase B (10 mmol/L ammonium formate/formic acid (998/2, v/v) (pH 3.5) from 98/2 to 70/30, the detection wave length was 280 nm. CYP1A2 phenotype was calculated from the metabolite ratio of (AFMU+1X+1U)/17U, CYP2A6 from the ratio of 17U/(17U+17X+1U+1X+AFMU), NAT2 from the ratio of AFMU/(AFMU+1U+1X) and XO from the ratio of 1U/1X+1U. RESULTS: The calibration curves of AFMU, 1U, 1X, 17U, 17X, 137X were linear over the range of 1.25-160 μmol/L, yielding correlation of coefficients from 0.991 to 0.999. The LOD were 2.5 ng/mL for AFMU, 1X, 1U and 1 ng/mL for 17U, 17X, 137X. Recoveries for the analytes wereranged from 81%-94%, Intra-and Inter-day coefficients of variation were ranged from 2.56%-9.48% and 5.74%-10.91%, respectively. After logarithmic transformation of these metabolite ratios, phenotype of CYP1A2, CYP2A6, NAT2 were shown normal distribution, while the phenotype of XO was shown non-normal distribution with two subjects appearing with very low metabolic capacity. It was also found a negative association between the phenotype of CYP2A6 and CYP1A2 which might be explained by the fact that CYP2A6 plays an influential role in 17X metabolism. CONCLUSION: In brief, the experiment demonstrates an accurate, stable and replicable HPLC method for phenotyping of these enzymes in Chinese volunteers.
基金This work was supported by research grants from the National Natural Science Foundation of China , C30528026,C30672497the China Medical Board of NewYork grants 99-697 and 01-755 .
文摘AIM: This study is aimed to investigate Runx2’s regulation by phytoestrogens resveratrol and genistein, screen for Runx2 mutation in Chinese cleidocranial dysplasia(CCD) patients, also determine the functional difference between Runx2’s two major isoforms-type I and type II. METHODS: The simian virus 40 large T antigens (SV40LT) gene was used to establish immortalized hBMSCs and the cell line were then identified by specific surface markers confirmation and pro-longed life span and renewable proliferative capacity illustration. Then we tested resveratrol and genistein’s regulation on the cell line by monitoring several osteoblastic markers and invested the possible involved pathway by western blotting. Subsequently, we determined the functional difference of Runx2’s two major isoforms-type I and type II-in osteoblastic differentiation by RNAi. Also for the first time we screened for the Runx2 mutations in Chinese CCD patients by DNA analysis. RESULTS: We successfully established a permanent hBMSCs by stable transfection of SV40LT. Based on this cell line platform, we illustrated that phytoestrogens resveratrol and genistein regulated Runx2’s expression in osteoblastic differentiation and might partly via MAPK pathway. We also found that type I and type II play a different role in osteoblastic differentiation process, during which type I major increased in the early phase and important for the cell proliferation while type II predominantly functioned in the late stage and necessary for the cell maturation. What’s more, we sequencing coding domains and promoter domains of Runx2 from 9 patients in 3 different CCD familial cases and found two nucleotide changes. CONCLUSION: In this paper, we set up an immortalized hBMSC line by stable transfection of SV40LT which brings convenience for the later studies, reveals that resveratrol and genistein are capable of promote osteoblastic differentiation and are probably via MAPK pathway, also finds that type I major functions in the early stage of osteoblastic differentiation while type II predominantly functions in the late stage, which for the first time distinguishes their effects and gave new hints for bone-related diseases therapies. Moreover, the investigation on RUNX2 mutations in CCD patients adds new records to the repertoire of RUNX2 mutations in China.
文摘AIM: Itopride, which is a dopamine D2 antagonist with acetylcholinesterase inhibitory actions, is often prescribed for patients with functional dyspepsia. The primary metabolite in humans is the N-oxide, generated by oxidation of the tertiary amine N-dimethyl group. The urinary excretions of itopride and its N-oxide were 3.7% and 75.4%, respectively, in healthy subjects after a single oral administration at a therapeutic dose. Studies support a predominant role of FMO3 in the formation of itopride N-oxide in human liver microsomes. In addition, itopride appears to be a suitable probe for human liver FMO3. Our aim was to establish a simple method adopting a one-step liquid-liquid extraction with dichloromethane followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection to simultaneously determine itopride and its N-oxide in human plasma and urine for FMO3 pharmacogenetics study, using sulpiride as an internal standard (IS). METHODS: Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 360.1>166.4 for itopride, m/z 376.1>165.5 for itopride N-oxide and m/z 342.9>112.2 for IS, respectively. Analytes were chromatographed on an Intersil ODS-3 reverse-phase chromatographic column (2.1 mm×150 mm, 5 μm) by isocratic elution with water (1000 mL water added 1 mL formic acid)-acetonitrile (60∶40, v/v), the flow rate was 0.2 mL/min with a total analysis time of 3 min per run. RESULTS: The linearity for itopride and its N-oxide were in the range of 0.25-1 000 ng/mL and 0.5-1 000 ng/mL, respectively, both in plasma and urine (r2=0.999). The recovery of itopride was 95.8% for plasma and 101.2% for urine and that of itopride N-oxide was 90.4% for plasma and 98.4% for urine. The intra-and inter-day RSD were <15% both in plasma and urine. CONCLUSION: The method described is successfully applied to the analysis of itopride and its N-oxide in plasma and urine samples generated after administration of 50 mg itopride hydrochloride in 18 healthy male volunteers who were genetyped according to FMO3 genetic polymorphism.
文摘AIM: The inhibition of organic anion transporting polypeptide 1B1 (OATP1B1) on the pharmacokinetics of rosuvastatin is unknown. Hence, the effect of ursodeoxycholic acid (UDCA) on the kinetics of rosuvastatin in healthy volunteers is to be investigated. METHODS: The inhibition effect of long term use of UDCA on rosuvastatin kinetics was studied in 12 subjects in a randomized, crossover study. Each subject received 500 mg UDCA once daily continuously for 14 days. A single oral dose of 20 mg rosuvastatin was given on study day 15 and 34 separated by 2 weeks. Plasma concentrations of rosuvastatin were above the limits of quantitation for up to 72 h after dosing. RESULTS: UDCA significantly increased AUC0-72 and AUC0-∞ of rosuvastatin to 146%±55% (P=0.008) and 167%±73% (P=0.004) compared with those of the control group and CL/F decreased 75%±19% (P=0.003). The results confirmed the in vitro study that UDCA inhibited OATP1B1 activity via hepatic nuclear factor 1a (HNF1a). CONCLUSION: Inhibition of HNF1a and hepatic uptake may have consequences on clinic outcomes of drugs like rosuvastatin mainly excreted by hepatobiliary system.
文摘Rifampin, a member of the rifamycin class of antibiotics, is well known for its ability to activate the pregnant X receptor and induce drug-metabolizing enzymes and transporters. Available data suggest rifampin entry into hepatocytes is mediated by OATP1B1. Accordingly, it is therefore plausible that modulation of the intracellular concentration of rifampin by OATP1B1 genetic polymorphisms would influence the degree of CYP3A induction. AIM: To study the association between haplotypes of the SLCO1B1 and the rifampicin-mediated inducible CYP3A4 activity. A single-point determination of midazolam plasma concentration method was developed to assess the constitutive and inducible CYP3A4 activity. A pharmacokinetic study of a single dose of 450 mg rifampicin was conducted to evaluate the mechanism of rifampicin-midazolam interaction in different SLCO1B1 genotypic subjects. METHODS: Twenty-three healthy volunteers with different SLCO1B1 haplotypes (7 for SLCO1B1*1a/*1a, 7 for SLCO1B1*1b/*1b, 7 for SLCO1B1*1b/*15 and 2 for SLCO1B1*15/*15) were enrolled in this study. Each was given a single oral dose of 7.5 mg midazolam on day 0 and day 6. Rifampicin of 450 mg was given from day 1 to day 5. Plasma concentrations of midazolam were measured for up to 8 hours by LC-MS, and its pharmacokinetic parameters were analyzed. Plasma concentrations of a single oral dose of 450 mg rifampicin were measured for up to 12 hours. RESULTS: A significant correlation (r2=0.763, P<0.001, n=23) was found between AUC(0-∞) and the single plasma concentration of midazolam at 2.5 hour (C2.5 h). The 2.5 h midazolam measurement was an optimal predictor of CYP3A phenotype. However, the percentage reduction of AUC(0-∞) or C2.5 h in different SLCO1B1 haplotypes was not significantly different. The pharmacokinetics parameters of rifampin were not significantly different between the 521T>C mutant group and the control group. CONCLUSION: A single blood concentration at 2.5 h after 7.5 mg oral midazolam intake can be used to predict CYP3A activity. The SLCO1B1 haplotypes do not influence the extent of inducible CYP3A activity by rifampin. SLCO1B1 genotypes has no significant impact on the disposition of rifampin in vivo.
文摘AIM: To develop and validate a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for quantifying trimetazidine in human plasma. METHODS: Sample preparation was based on extracted using acetonitrile only. Chromatography was performed on a C18 analytical column and the retention times were 1.9 and 2.6 min for trimetazidine and cetirizine (internal standard), respectively. The ionization was optimized using ESI (+) and enhanced selectivity was achieved using tandem mass spectrometric analysis via two MRM functions, m/z:267→m/z:181 and m/z:389→m/z:201 for trimetazidine and cetirizine. RESULTS: The calibration curve ranged from 0.77 to 198 ng/mL. The inter-day precision and accuracy and the relative standard deviation (RSD) were<15%. The analyte was shown to be stable over the timescale of the whole procedure. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples. CONCLUSION: The experiment demonstrates an accurate, stable and reproducible LC-MS/MS method for quantifying trimetazidine in human plasma.
基金This project was supported by the National Natural Science Foundation of China grant(No 30572230) the Supported Program for New Century Excellent Talents in University (NCET-04-0749) sponsored by Ministry of Education of China .
文摘AIM: To evaluate the expression of eukaryotic initiation factors 3(eIF3) subunit 170 (eIF3 P170) in lung cancer tissues and its association with chemotherapy response of lung cancer. METHODS: 31 paraffin imbedded slices of lung cancer tissue from fiberscope diagnosis, 20 samples of benign lung tissues from inflammatory pseudotumor and bronchiectasis, and 10 samples of normal lung tissues from surgical operation were collected. The protein expression of eIF3 p170 in lung-cancer tissues, benign lesion tissues, and normal lung tissues were determined by immunohistochemical staining. RESULTS: The positive ratio of eIF3 p170 expression in lung cancer tissues is higher than those in normal and benign tissues, the lung cancer patients with a higher expression level of eIF3 p170 seems to be more sensitive to chemotherapy. Here, we also found that down-regulation of expression of eIF3 p170 could inhibit the growth of human lung adeno-carcinoma cell A549 cells and decrease the sensitivity of A549 to cisplatin. CONCLUSION: Our data suggest that eIF3 p170 may be involved in the pathogenesis of lung cancer and it appears to be associated with chemotherapy response of lung cancer.
基金Supported by foundation for build-up of key disciplines from the Education Department of Hunan province .
文摘AIM: To determine whether the use of an antioxidant reagent coenzyme Q10 can protect human dopaminergic cell line SHSY-5Y against rotenone-induced apoptosis. METHODS: Cell viability was quantified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the apoptosis induced by rotenone was observed by Hoechst 33342, propidium iodide, and calcein AM staining in SHSY-5Y cells. RESULTS: Rotenone, a commonly used natural pesticide, inhibitor of mitochondrial respiratory chain complex I, was shown to decrease cell viability and induce apoptosis in SHSY-5Y cells. Pretreated with coenzyme Q10, the electron transporter in the mitochondrial respiratory chain, remarkably increased cell viability as well as significantly reduced the percentage of apoptotic SHSY5Y cells induced by rotenone. CONCLUSION: Coenzyme Q10 has a beneficial effect in protecting against rotenone-induced apoptosis in SHSY-5Y cells. The results support the hypothesis that coenzyme Q10 is a component of the antioxidant machinery that protects cell membranes from oxidative damage and decreases apoptosis. Further evaluation is required to determine whether the neuroprotective action of coenzyme Q10 can be used for the prevention and therapy of neurodegenerative diseases.
