Identification of Tiletamine, Zolazepam and Their Metabolites in Drug Facilitated Sexual Assault by GC-QTOF-MS

Objective To identify tiletamine, zolazepam and their metabolites in samples from drug facilitated sexual assault by gas chromatography-quadrupole time of flight mass spectrometry （GC-QTOF-MS）. Methods Urine samples of victims were collected, and detected by GC-QTOF-MS after liquid-liquid extraction and concentration. The molecular formula of fragments ions was identified by determination of accurate mass numbers, to detect related substances. Results Tiletamine, zolazepam, three metabolites of tiletamine and two metabolites of zolazepam were identified in urine samples from actual cases. Conclusion GC-QTOF-MS provides abundant and accurate information of fragment ions mass numbers, which can be used for qualitative identification of tiletamine, zolazepam and their metabolites in drug facilitated sexual assault.

Down-regulation of mitochondrial ATPase by hypermethylation mechanism in chronic myeloid leukemia is associated with multidrug resistance

BACKGROUND

To identify novel proteins involved in multidrug resistance in chronic myeloid leukemia (CML).

MATERIALS AND METHODS

Comparative proteomics was used to screen multidrug resistance-related proteins from K562 and K562/A02; the differently expressed proteins were further confirmed by western blot and real-time PCR. short hairpin RNA (shRNA) assay was applied to determine the relationship between candidate protein and adriamycin resistance. Bisulfite sequencing was carried out to assess methylation status of candidate multidrug resistance-related gene promoter. K562/A02 was treated with 5-azacytidine or trichostatin A (TSA); multidrug resistance phenotype and corresponding protein or gene changes were detected.

RESULTS

Seventeen proteins with altered abundances of more than twofold were detected, among which mitochondrial ATPase in K562/A02 was significantly down-regulated. Suppressing mitochondrial ATPase by shRNA could enhance adriamycin resistance and antiapoptosis activity of K562. The promoter hypermethylation in mitochondrial ATPase was found to be attributed to the adriamycin-resistant phenotype of both K562/A02 (methylated frequency 18.18%) and CML primary cells in accelerated phase (methylated frequency 7.95%) or blast crisis (methylated frequency 26.59%). Inhibition of hypermethylation increased adriamycin sensitivity of K562/A02. A synergistic effect on reversing adriamycin-resistant phenotype was obtained when 5-azacytidine was combined with TSA.

CONCLUSION

Down-regulation of mitochondrial ATPase can lead to adriamycin resistance in CML and the mechanism is associated with DNA methylation regulation.

Adjuvant therapy with imatinib in gastrointestinal stromal tumor (GIST) patients with intermediate or high risk: Analysis from a single-center contrast study

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Background: Imatinib benefits the patients with metastatic GIST but whether it is effective in the adjuvant setting after complete tumor resection of primary GIST is questionable. Methods: Patients who had undergone complete tumor resection with intermediate or high risk of recurrence (define) were enrolled in a single-center non-randomized open contrast study. Patients had adjuvant therapy with imatinib (400mg once a day) for 3 years commencing within 12 weeks of tumor resection, or had follow-up alone. We performed c-kit and PDGFRA mutation analysis for patients with archival tumor samples. The primary objective was recurrence-free survival (RFS) and the second objective was correlation of gene mutation profile with efficacy of adjuvant therapy. Results: One hundred and five patients were enrolled: 56 patients in adjuvant therapy group and 49 patients in control group. Median follow-up was 30 months (range 12–62); Median treatment duration in adjuvant therapy group were 20 months (range 12–36); There was relatively higher 1-year and 2-year RFS in the adjuvant therapy group compared with the control group (100% vs 89.8%,94.4% vs 60.0%) (Log-RankP< 0.001). Hazard risk was 0.13 (95% CI 0.039–0.438, P= 0.001) in Cox proportional hazard regression model. For further sub-group analysis, Log-rank and Cox regression analysis showed that adjuvant therapy could significantly decrease recurrence risk in patients with high risk disease (define)(2-year RFS: 91.5% vs 46,2%, Log-Rank: P<0.001, HR:0.107 (95%CI 0.031–0.370), P<0.001). c-kit and PDGFRA mutation were analyzed in forty-nine patients. There was a better survival benefit from adjuvant therapy for patients with c-kit exon 11 mutation. Conclusions: Adjuvant therapy with imatinib can improve 1-year and 2-year recurrence-free survival for patients with an intermediate or high risk of recurrence after complete tumor resection.

No significant financial relationships to disclose.