Objective To establish a fast and sensitive method for the detection of 8-hydroxy-2’-deoxyguanosine （8-OHdG） in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid （INH） -induced oxidative D...Objective To establish a fast and sensitive method for the detection of 8-hydroxy-2’-deoxyguanosine （8-OHdG） in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid （INH） -induced oxidative DNA damage. Methods Precision-cut liver slices （300 μm） were prepared from male rats, and incubated with INH （0.018 mol/L） for 2 h after 1 h preincubation. DNA in the slices was extracted and digested into free nucleosides at 37℃ . The samples were injected into HPLC-MS/MS after the proteins were removed. The level of oxidative DNA damage was estimated using the ratio of 8-OHdG to deoxyguanosine （dG）. Results The limit of detection of 8-OHdG was 1 ng/mL （S/N=3） and the intra-assay relative standard variation was 3.38% when one transition 284.3/168.4 was used as a quantifier and another two transitions 284.3/140.2, 306.1/190.2 as qualifiers. 8-OHdG and dG were well separated, as indicated by elution at 10.02 and 7.37 min, respectively. INH significantly increased the ratio of 8-OHdG to dG in rat liver slices （P〈0.05）. Conclusion 8-OHdG in precision-cut liver slices could be sensitively determined by HPLC-MS/MS. HPLC-MS/MS coupled with precision-cut tissue slices is a fast and reliable analytical technique to evaluate oxidative DNA damage of target tissues caused by procarcinogens and cytotoxins.展开更多
Precision-cut liver slice has been successfully used to study the mechanism of drug-induced hepatotoxicity, the prediction of liver toxicity, the discovery of early hepatic toxicity biomarker and the metabolism of dru...Precision-cut liver slice has been successfully used to study the mechanism of drug-induced hepatotoxicity, the prediction of liver toxicity, the discovery of early hepatic toxicity biomarker and the metabolism of drug in liver. We detected the expression of CYP3A4, CYP2B1 + CYP2B2 and CYP2E1 in precision-cut liver slice after co-cultured with monocrotaline or Tussilago farfara alkaloids to investigate the hepatotoxicity mechanism of those drugs. After co-culturing with monocrotaline or Tussilago farfara alkaloids for 6 hours, the expression of CYP3A4 in the microsome of precision-cut liver slices was detected by Western blot, and the expressions of CYP2B1 + CYP2B2 and CYP2E1 were detected by immunofluorescence. The results showed that monocrotaline induced the expression of CYP3A4 and CYP2B1 + CYP2B2, and Tussilago farfara alkaloids obviously up-regulated the expression of CYP2E1 and CYP3A4. Thus, we conclude that the up-regulation of CYP3A4, CYP2B1 + CYP2B2 and CYP2E1 may be one of the toxic mechanisms of liver injury of those drugs.展开更多
Adaptive layered Cartesian cut cell method is presented to solve the difficulty of the tmstructured hexahedral anisotropic Cartesian grids generation from the complex CAD model. ＂Vertex merging algorithm based on rel...Adaptive layered Cartesian cut cell method is presented to solve the difficulty of the tmstructured hexahedral anisotropic Cartesian grids generation from the complex CAD model. ＂Vertex merging algorithm based on relaxed AVL tree is investigated to construct topological structure for stereo lithography （STL） files, and a topology-based self-adaptive layered slicing algorithm with special features control strategy is brought forward. With the help of convex hull, a new points-in-polygon method is employed to improve the Cartesian cut cell method. By integrating the self-adaptive layered slicing algorithm and the improved Cartesian cut cell method, the adaptive layered Cartesian cut cell method gains the volume data of the complex CAD model in STL file and generates the unstructured hexahedral anisotropic Cartesian grids.展开更多
基金This research was supported by the National Natural Science Foundation of China (No. 30600773).
文摘Objective To establish a fast and sensitive method for the detection of 8-hydroxy-2’-deoxyguanosine （8-OHdG） in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid （INH） -induced oxidative DNA damage. Methods Precision-cut liver slices （300 μm） were prepared from male rats, and incubated with INH （0.018 mol/L） for 2 h after 1 h preincubation. DNA in the slices was extracted and digested into free nucleosides at 37℃ . The samples were injected into HPLC-MS/MS after the proteins were removed. The level of oxidative DNA damage was estimated using the ratio of 8-OHdG to deoxyguanosine （dG）. Results The limit of detection of 8-OHdG was 1 ng/mL （S/N=3） and the intra-assay relative standard variation was 3.38% when one transition 284.3/168.4 was used as a quantifier and another two transitions 284.3/140.2, 306.1/190.2 as qualifiers. 8-OHdG and dG were well separated, as indicated by elution at 10.02 and 7.37 min, respectively. INH significantly increased the ratio of 8-OHdG to dG in rat liver slices （P〈0.05）. Conclusion 8-OHdG in precision-cut liver slices could be sensitively determined by HPLC-MS/MS. HPLC-MS/MS coupled with precision-cut tissue slices is a fast and reliable analytical technique to evaluate oxidative DNA damage of target tissues caused by procarcinogens and cytotoxins.
文摘Precision-cut liver slice has been successfully used to study the mechanism of drug-induced hepatotoxicity, the prediction of liver toxicity, the discovery of early hepatic toxicity biomarker and the metabolism of drug in liver. We detected the expression of CYP3A4, CYP2B1 + CYP2B2 and CYP2E1 in precision-cut liver slice after co-cultured with monocrotaline or Tussilago farfara alkaloids to investigate the hepatotoxicity mechanism of those drugs. After co-culturing with monocrotaline or Tussilago farfara alkaloids for 6 hours, the expression of CYP3A4 in the microsome of precision-cut liver slices was detected by Western blot, and the expressions of CYP2B1 + CYP2B2 and CYP2E1 were detected by immunofluorescence. The results showed that monocrotaline induced the expression of CYP3A4 and CYP2B1 + CYP2B2, and Tussilago farfara alkaloids obviously up-regulated the expression of CYP2E1 and CYP3A4. Thus, we conclude that the up-regulation of CYP3A4, CYP2B1 + CYP2B2 and CYP2E1 may be one of the toxic mechanisms of liver injury of those drugs.
基金This project is supported by National Natural Science Foundation of China (No. 60375020, No. 50305033)Provincial Natural Science Foundation of Zhejiang, China (No. Y105430).
文摘Adaptive layered Cartesian cut cell method is presented to solve the difficulty of the tmstructured hexahedral anisotropic Cartesian grids generation from the complex CAD model. ＂Vertex merging algorithm based on relaxed AVL tree is investigated to construct topological structure for stereo lithography （STL） files, and a topology-based self-adaptive layered slicing algorithm with special features control strategy is brought forward. With the help of convex hull, a new points-in-polygon method is employed to improve the Cartesian cut cell method. By integrating the self-adaptive layered slicing algorithm and the improved Cartesian cut cell method, the adaptive layered Cartesian cut cell method gains the volume data of the complex CAD model in STL file and generates the unstructured hexahedral anisotropic Cartesian grids.
