@article{KuntzenKuhnKuntzenetal.2016, author = {Kuntzen, Thomas and Kuhn, Sereina and Kuntzen, Daniela and Seifert, Burkhardt and M{\"u}llhaupt, Beat and Geier, Andreas}, title = {Influence of Ribavirin Serum Levels on Outcome of Antiviral Treatment and Anemia in Hepatitis C Virus Infection}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {7}, doi = {10.1371/journal.pone.0158512}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166888}, pages = {e0158512}, year = {2016}, abstract = {Background Ribavirin blood levels vary considerably between patients with standard weight-based dosing. Their impact on sustained virological response (SVR) with pegylated interferon and ribavirin is controversial, but has mostly been studied before the IL28b gene polymorphism as a possible confounder was discovered. Methods The impact of serum ribavirin trough levels at week 4, at the end of treatment and of mean levels across the entire antiviral treatment with pegylated interferon and ribavirin on relapse, SVR rates and anemia was retrospectively studied by univariate and multivariable logistic regression analyses in 214 patients with HCV genotype 1-4 infection, including 88 patients with available IL28b genotyping. Results Mean ribavirin levels varied between 0.68-5.65 mg/l and significantly differed between patients with or without SVR. By multivariable regression including age, sex, HCV viral load, HCV genotype, liver fibrosis stage, prior treatments, immunosuppression and IL28b genotype, ribavirin levels consistently displayed significant influence on SVR and relapse without indication for a specific importance of higher concentrations early or late in the treatment course. Although hemoglobin decline was on average more pronounced in patients with higher ribavirin levels, hemoglobin remained relatively stable in a significant proportion of these, indicating that ribavirin levels alone are insufficient to predict anemia. Conclusion While data are scarce to draw conclusions applicable for modern DAA therapies, these results support ribavirin treatment based on serum levels instead of purely weight-based dosing in combination with pegylated interferon.}, language = {en} } @article{vonBuerenOehlerShalabyetal.2011, author = {von Bueren, Andr{\´e} O. and Oehler, Christoph and Shalaby, Tarek and von Hoff, Katja and Pruschy, Martin and Seifert, Burkhardt and Gerber, Nicolas U. and Warmuth-Metz, Monika and Stearns, Duncan and Eberhart, Charles G. and Kortmann, Rolf D. and Rutkowski, Stefan and Grotzer, Michael A.}, title = {c-MYC expression sensitizes medulloblastoma cells to radio- and chemotherapy and has no impact on response in medulloblastoma patients}, series = {BMC Cancer}, volume = {11}, journal = {BMC Cancer}, number = {74}, doi = {10.1186/1471-2407-11-74}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134185}, pages = {1-11}, year = {2011}, abstract = {Background: To study whether and how c-MYC expression determines response to radio-and chemotherapy in childhood medulloblastoma (MB). Methods: We used DAOY and UW228 human MB cells engineered to stably express different levels of c-MYC, and tested whether c-MYC expression has an effect on radio-and chemosensitivity using the colorimetric 3-(4,5-dimethylthiazol- 2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay, clonogenic survival, apoptosis assays, cell cycle analysis, and western blot assessment. In an effort to validate our results, we analyzed c-MYC mRNA expression in formalin-fixed paraffin-embedded tumor samples from well-documented patients with postoperative residual tumor and compared c-MYC mRNA expression with response to radio-and chemotherapy as examined by neuroradiological imaging. Results: In DAOY -and to a lesser extent in UW228 -cells expressing high levels of c-MYC, the cytotoxicity of cisplatin, and etoposide was significantly higher when compared with DAOY/UW228 cells expressing low levels of c-MYC. Irradiation-and chemotherapy-induced apoptotic cell death was enhanced in DAOY cells expressing high levels of c-MYC. The response of 62 of 66 residual tumors was evaluable and response to postoperative radio-(14 responders (CR, PR) vs. 5 non-responders (SD, PD)) or chemotherapy (23 CR/PR vs. 20 SD/PD) was assessed. c-MYC mRNA expression was similar in primary MB samples of responders and non-responders (Mann-Whitney U test, p = 0.50, ratio 0.49, 95\% CI 0.008-30.0 and p = 0.67, ratio 1.8, 95\% CI 0.14-23.5, respectively). Conclusions: c-MYC sensitizes MB cells to some anti-cancer treatments in vitro. As we failed to show evidence for such an effect on postoperative residual tumors when analyzed by imaging, additional investigations in xenografts and larger MB cohorts may help to define the exact function of c-MYC in modulating response to treatment.}, language = {en} }