A rapid and sensitive liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for quantification of sitagliptin in human plasma and urine had been developed. This method was applied to the pharmacokinetics study of sitagliptin tablet after single- and multiple-dosing in Chinese population. Plasma samples were prepared by a liquid-liquid extracted method, and urine samples were diluted. Compounds were analyzed by multiple reaction monitoring (MRM) mode with a electrospray ionization (ESI) interface. Mobile phase consisted of methanol and water (85 : 15, v/v). The linear concentration range of calibration curve was 0.5-1 000 ng.mL-1. and 0.2-100 µg.mL , intra-run/between-run accuracy was 98.98%-103.69% and 97.63%-102.29%, intra-run/between-run precision was <5.51% and 4.26% for plasma and urine sample, respectively. The stability of sitagliptin stock solution was tested for 55 days at -30 °C. Sitagliptin was stable when stored under the following conditions: 24 hours in the autosampler after sample preparation; 24 hours at room temperature, after 3 freeze and thaw cycles (from -30 °C to room temperature), 40 days at -30 °C for plasma and urine samples. The absolute recovery in plasma was 71.1%, and no matrix effect was founded. This method was proved simple, specific, sensitive, rapid and suitable for pharmacokinetics study of sitagliptin in human being.
Calibration ; Chromatography, Liquid ; Humans ; Liquid-Liquid Extraction ; Sitagliptin Phosphate ; blood ; pharmacokinetics ; urine ; Tandem Mass Spectrometry

The work aims to study the drug metabolizing enzymes involved in the metabolism of butylphthalide and evaluate the induction and inhibition activities of butylphthalide on CYP450 isoenzymes by using in vitro (liver microsome incubation system of rats and human) and in vivo (CYP induced model of rats) method. Butylphthalide was incubated with selective inhibitors of CYP450, and its metabolic rate was determined to identify the metabolizing isoenzymes of NBP in rat (normal and induced rats) and human liver microsomes. The in vitro inhibition effect of butylphthalide on 6 main liver microsomal CYP450 isoenzymes was evaluated by using probe drugs; the induction and inhibition activities in vivo of butylphthalide on CYP450 isoenzymes were evaluated by NBP ig dosing (160 mg x kg(-1)) and iv dosing (20 mg x kg(-1)) in rats. After adding the specific inhibitors of CYP2C11, 2E1 and 3A 1/2 for rat, CYP2C19, 2E1 and 3A4/5 for human, the metabolism of NBP in rat and human liver microsomes were reduced 38.8%, 86.2%, 78.4% and 51.0%, 92.0%, 58.9% of control, respectively. The metabolic rates of NBP in CYP2E1 and 3A 1/2 induced rat liver microsomes were increased 25.5% and 68.9%. High concentration of NBP (≥ 200 μmol x L(-1), in vitro) could inhibit the activities of CYP1A2, 2C6, 2C11 and 2D2 in rats, and high concentration of NBP ( ≥ 15 μmol x L(-1), in vitro) could inhibit the activity of CYP2C19 in human. All the results indicated that NBP should be mainly metabolized by CYP2E1, 2C11 and 3A 1/2 in rats and CYP2E1, 2C19 and 3A4/5 in human. High concentration of NBP could inhibit human CYP2C19 in vitro. No significant induction/inhibition effects of NBP were observed on rat liver CYP450 isoforms after ig 160 mg x kg(-1) NBP or iv 20 mg x kg(-1) NBP.

A rapid and sensitive liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for quantification of sitagliptin in human plasma and urine had been developed. This method was applied to the pharmacokinetics study of sitagliptin tablet after single- and multiple-dosing in Chinese population. Plasma samples were prepared by a liquid-liquid extracted method, and urine samples were diluted. Compounds were analyzed by multiple reaction monitoring (MRM) mode with a electrospray ionization (ESI) interface. Mobile phase consisted of methanol and water (85 : 15, v/v). The linear concentration range of calibration curve was 0.5-1 000 ng.mL-1. and 0.2-100 µg.mL , intra-run/between-run accuracy was 98.98%-103.69% and 97.63%-102.29%, intra-run/between-run precision was <5.51% and 4.26% for plasma and urine sample, respectively. The stability of sitagliptin stock solution was tested for 55 days at -30 °C. Sitagliptin was stable when stored under the following conditions: 24 hours in the autosampler after sample preparation; 24 hours at room temperature, after 3 freeze and thaw cycles (from -30 °C to room temperature), 40 days at -30 °C for plasma and urine samples. The absolute recovery in plasma was 71.1%, and no matrix effect was founded. This method was proved simple, specific, sensitive, rapid and suitable for pharmacokinetics study of sitagliptin in human being.

Adolescent ; Adult ; Automobile Driving ; China ; Electrocardiography ; Female ; Heart ; physiopathology ; Humans ; Male ; Middle Aged ; Noise, Occupational ; adverse effects ; Occupational Exposure ; adverse effects ; Stress, Psychological ; etiology ; physiopathology ; Vibration ; adverse effects

The work aims to study the drug metabolizing enzymes involved in the metabolism of butylphthalide and evaluate the induction and inhibition activities of butylphthalide on CYP450 isoenzymes by using in vitro (liver microsome incubation system of rats and human) and in vivo (CYP induced model of rats) method. Butylphthalide was incubated with selective inhibitors of CYP450, and its metabolic rate was determined to identify the metabolizing isoenzymes of NBP in rat (normal and induced rats) and human liver microsomes. The in vitro inhibition effect of butylphthalide on 6 main liver microsomal CYP450 isoenzymes was evaluated by using probe drugs; the induction and inhibition activities in vivo of butylphthalide on CYP450 isoenzymes were evaluated by NBP ig dosing (160 mg x kg(-1)) and iv dosing (20 mg x kg(-1)) in rats. After adding the specific inhibitors of CYP2C11, 2E1 and 3A 1/2 for rat, CYP2C19, 2E1 and 3A4/5 for human, the metabolism of NBP in rat and human liver microsomes were reduced 38.8%, 86.2%, 78.4% and 51.0%, 92.0%, 58.9% of control, respectively. The metabolic rates of NBP in CYP2E1 and 3A 1/2 induced rat liver microsomes were increased 25.5% and 68.9%. High concentration of NBP (≥ 200 μmol x L(-1), in vitro) could inhibit the activities of CYP1A2, 2C6, 2C11 and 2D2 in rats, and high concentration of NBP ( ≥ 15 μmol x L(-1), in vitro) could inhibit the activity of CYP2C19 in human. All the results indicated that NBP should be mainly metabolized by CYP2E1, 2C11 and 3A 1/2 in rats and CYP2E1, 2C19 and 3A4/5 in human. High concentration of NBP could inhibit human CYP2C19 in vitro. No significant induction/inhibition effects of NBP were observed on rat liver CYP450 isoforms after ig 160 mg x kg(-1) NBP or iv 20 mg x kg(-1) NBP.
Animals ; Benzofurans ; pharmacology ; Cytochrome P-450 Enzyme Inhibitors ; pharmacology ; Cytochrome P-450 Enzyme System ; metabolism ; Humans ; Isoenzymes ; metabolism ; Liver ; metabolism ; Microsomes, Liver ; metabolism ; Rats

Objective:To observe the effect of thoracic infusion of pseudomonas aeruginosa injection in malignant pleural effusion. Methods:A total of 90 patients with malignant pleural effusion were randomly divided into treatment group (31 cases),control group A (29 cases) and control group B(30 cases). Treatment group was treated with pseudomonas aeruginosa through intrathoracic infusion. Control group A and B were respectively treated with cisplatin and interleukin-2 through intrathoracic infusion. The clinical efficacy and adverse reaction were compared among the three groups. Results:The total effective rate of treatment group was 80.6%,the total effective rates of the control group A and B were 51.7%and 56.7%respectively.Compared with that of contral groups, the total effective rate of treatment group was higher, and the differences were statistically significant (P<0.05). The incidence of serious side effects and toxicity was lower in treatment group than in control groups. Conclusion:The effect of thoracic infusion of pseudomonas aeruginosa injection for malignant pleural effusion is significant, and the adverse reaction is mild. Thus it is worth to be promoted clinically.

A white-rot fungi Rigidoporus sp.W-1 which could produce laccase was isolated. The fermentation conditions in shaking flasks were investigated. The optimal carbon source was wheat bran and (NH 4) 2SO 4 was the optimal nitrogen source. The components of the medium were optimized by orthogonal experiment. When W-1 was cultured under the optimum conditions, the activity of laccase could get to 7.1U/mL in 7 days.A great amount of crude laccase could be obtained by adding fresh medium to the 7 days old mycelium.

Objective To evaluate the uncertainty of the pseudo-ginsenoside GQ (PGQ) concentration in human plasma by HPLC-MS/MS.Methods The whole process of PGQ determination by HPLC-MS/MS in human plasma was evaluated and the uncertainty caused by repeatability,weighing,standard solution preparation,biological sample preparation,extraction recovery process,recovery,instrument precision and calibration curve fitting were evaluated,respectively.The combined and expanded uncertainty values were both calculated.Results The expanded uncertainty values for low (15.16 ng·mL-1),medium (2 516.67 ng·mL-1) and high (3 902.00 ng·mL-1) levels of PGQ were 1.39,177.74 and 262.69 ng·mL-1,respectively (P =95 ％,k =2).Conclusion The uncertainty of the PGQ determination in human plasma by HPLC-MS/MS is mainly caused by recovery,repeatabihty and sample preparation at low concentration,by sample preparation and recovery at medium and high concentration.

Objective To study the expression level and clinical significance of bcl-XL gene in childhood medulloblastoma.Methods The expression of Bcl-XL protein and bcl-XL mRNA were determined by immunohistochemical staining and in situ hybridization in 41 samples of medulloblastoma tissues,as well as 20 normal brain tissues.Results The positive rate of Bcl-XL protein(90.2%) and bclXL mRNA(95.1%) in medulloblastoma group were significantly higher than those in normal human brain tissues(all P

ObjectiveTo evaluate the clinical efficacy of cutaneous branches of reverse second and third dorsal metacarpal artery fasciocutaneous flaps for repair of distal- and middle-segment finger soft tissue defects. MethodsA total of 14 patients with distal- and middle-segment finger soft tissue defects complicated by exposure of the phalanx or tendon were repaired by using cutaneous branches of second and third dorsal metacarpal artery fasciocutaneous flaps ranging between 2.0 cm × 4.5 cm and 3.0 cm × 7.0 cm.ResuitsAll of the skin flaps survived after surgery.Follow-up data during a 6-40 month period showed that the flaps exhibited a satisfactory appearance.They were not fat or clumsy,with a 2-point discrimination of 59 mm,and there was good recovery of finger function.The donor site was able to be directly sutured without dermoplasty.Pigmented linear surgical streaks appeared in the donor site.Conclusion The cutaneous branches of Second and third dorsal metacarpal artery fasciocutaneous flaps provide a good approach for the repair of distal- and middle-segment finger soft tissue defects and functional reconstruction because of convenient dissection,little trauma,sufficient use of the dorsal metacarpal artery.