Detection of Carbamazepine and Its Metabolites in Blood Samples by LC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a method for the detection of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS).@*METHODS@#The blood samples were treated with 1-butyl-3-methylimidazolium hexafluorophosphate as an extraction solvent. The samples were extracted by ultrasound-assisted extraction and separated by ZORBAX Eclipse Plus C18, 95Å column. The mobile phase A aqueous solution containing 0.1% formic acid and 10 mmol/L ammonium acetate, and mobile phase B mixed organic solvent containing acetonitrile/methanol (Vacetonitrile∶Vmethanol=2∶3) were used for gradient elution at the flow rate of 1.00 mL/min. An electrospray ion source in positive mode was used for detection in the multiple reaction monitoring.@*RESULTS@#The linearities of carbamazepine and its metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 10,11-dihydro-10-hydroxycarbamazepine in blood samples were good within the corresponding range, with correlation coefficients (r) greater than 0.995 6. The limits of detection were 3.00, 0.40 and 1.30 ng/mL, respectively. The limit of quantitation were 8.00, 1.00 and 5.00 ng/mL, respectively. The extraction recoveries ranged from 76.00% to 106.44%. The relative standard deviations of the intra-day and inter-day precisions were less than 16%. Carbamazepine and its main metabolite 10,11-dihydro-10,11-epoxycarbamazepine were detected in blood samples of death cases with a mass concentration of 2.71 μg/mL and 252.14 ng/mL, respectively.@*CONCLUSIONS@#This method has high sensitivity and good selectivity, which is suitable for the detection of carbamazepine and its metabolites in blood samples, and can be used for carbamazepine-related forensic identifications.

Postmortem Distribution and Postmortem Redistribution of Carbofuran-7-Phenyl Glucuronic Acid in Rabbits / 法医学杂志

OBJECTIVES@#To establish a carbofuran intragastric administration death model in rabbits, and to observe the postmortem distribution and postmortem redistribution of carbofuran-7-phenyl glucuronic acid (Glu-7PH) in rabbits.@*METHODS@#The postmortem distribution: Rabbits were given an administration of 1/2LD50, LD50, 2LD50 carbofuran. Dead rabbits were dissected immediately. Rabbits that had remained alive 2 hours were sacrificed by carbon dioxide (CO2) inhalation and dissected immediately. The myocardium, cardiac blood, liver, spleen, lung, kidney, brain and right hindlimb muscle were collected. The postmortem redistribution: After giving an administration of 4LD50 carbofuran, the myocardium, cardiac blood, liver, spleen, lung, kidney, brain, and right hindlimb muscle were collected at 0, 12, 24, 48, and 72 h postmortem in supine position at 15 ℃ room temperature. The quantity of Glu-7PH was determined by LC-MS/MS.@*RESULTS@#The postmortem distribution: Among the three dose groups, there were significant differences in the quantities of Glu-7PH in different tissues. The postmortem redistribution: There was no significant difference in the Glu-7PH quantities in cardiac blood, mycardium, spleen, kidney, brain and right hindlimb muscle, but there was a significant difference in the Glu-7PH quantities in the liver and lung.@*CONCLUSIONS@#The mycardium, cardiac blood, liver, lung, kidney, brain and hindlimb muscle of rabbits can be used as appropriate samples for Glu-7PH detection. However, it should be noted that Glu-7PH was redistributed postmortem in rabbit liver and lung.

Effect of Danggui Buxuetang on PKD1/NF-κB/MnSOD Signal Pathway in Bleomycin-induced Pulmonary Fibrosis in Rats / 中国实验方剂学杂志

Objective:To observe the effect of Danggui Buxuetang on lung histopathology and protein kinase D1 (PKD1), nuclear transcription factor-κB (NF-κB) and manganese superoxide dismutase (MnSOD)-mediated oxidative stress pathway in rats with pulmonary fibrosis induced by bleomycin, so as to explore the mechanism of intervention of pulmonary fibrosis.Method:Thirty-two male SPF SD rats were randomly divided into sham operation group, model group, Danggui Buxuetang group and prednisone group, with 8 rats in each group. Except the sham operation group, the other groups were prepared through the intratracheal instillation with bleomycin. After modeling for 24 h, the rats of Danggui Buxuetang group were administered with Danggui Buxuetang (0.81 g·kg-1). The rats of prednisone group were given aqueous solution of prednisone (0.005 g·kg-1). The rats of sham operation group and model group were given the same volume of saline. After 14 days of administration, blood was collected from the femoral artery, serum was separated, and the lungs were taken by thoracotomy. The pathological changes of rat lung tissues were observed by hematoxylin-eosin staining (HE) and Masson trichrome staining, and graded by Szapiel score and Ashcroft score at the same time. The content of serum malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) were determined. Real-time fluorescent quantitative polymerase chain reaction (Real-time PCR) and Western blot were used to measure mRNA and protein expressions of PKD1, NF-κB, MnSOD.Result:Compared with the rats in sham operation group, the rats in model group had higher Szapiel scores and Ashcroft scores (P<0.05), higher serum MDA content , but lower SOD, CAT and GSH-Px activities(P<0.01), moreover, the rat lung tissues in model group had higher mRNA and protein expressions of PKD1, NF-κB and MnSOD (P<0.01) than those in sham operation group. Compared with the rats in model group, the Szapiel scores and Ashcroft scores of the rats in Danggui Buxuetang group were decreased significantly（P<0.05）. The serum MDA content was decreased significantly, and SOD, CAT, GSH-Px activities were increased, whereas mRNA and protein expressions of PKD1, NF-κB, MnSOD in the rat lung tissues were decreased（P<0.05，P<0.01）.Conclusion:Danggui Buxuetang can reduce the degree of pulmonary fibrosis by regulating the anti-oxidation pathway of PKD1/NF-κB/MnSOD mitochondrial nucleus and improving the body's antioxidant capacity.

Determination of Escitalopram in Biological Samples by Dispersive Liquid-Liquid Microextraction Combined with GC-MS/MS / 法医学杂志

Objective To establish a method for determination of escitalopram in biological samples by ultrasound-assisted ionic liquid-dispersive liquid-liquid microextraction combined with gas chromatography-tandem mass spectrometry （GC-MS/MS） and provide evidences for forensic determination of cases related to escitalopram. Methods The 1-hexyl-3-methylimidazolium hexafluorophosphate （[C6MIM][PF6]） was selected as an extract solvent to process biological samples. Ultrasound-assisted extraction was used on the samples. Then the samples were detected by GC-MS/MS. Results The linear range of escitalopram in blood and liver were 5.56-1 111.10 ng/mL and 0.025-5.00 mg/g, respectively. The correlation coefficient （r） were greater than 0.999, limit of detection （LOD） were 4.00 ng/mL and 2.00 μg/g, limit of quantitation （LOQ） were 14.00 ng/mL and 6.00 μg/g, respectively. The extraction recovery rates were all greater than 50%, the interday and intraday precision were less than 20%. Escitalopram was detected in blood and liver samples from the actual poisoning case by this method with a content of 1.26 μg/mL and 0.44 mg/g, respectively. Conclusion The ultrasound-assisted ionic liquid-dispersive liquid-liquid microextraction combined with GC-MS/MS is environment friendly, rapid, has good enriching effect and consumes less organic solvent and can be used for forensic determination of escitalopram related cases.