While vancomycin activity has been shown to be attenuated against SCVs of S. aureus, few data exist regarding daptomycin. The objective was to evaluate the pharmacodynamics of daptomycin against MK5108 cell line defined S. aureus mutants displaying the SCV phenotype.\n\nTwo S. aureus hemB mutants (Ia48 and III33) displaying the SCV phenotype and their parental strains (COL and Newman) were evaluated. Time-kill experiments were performed using
a starting inoculum of 10(6) cfu/mL at 0, 0.25, 0.5, 1, 2, 4, 8, 16, 32 and 64 times the MIC. Samples were obtained at 0, 1, 2, 4, 6, 8 and 24 h, plated and incubated to determine colony counts. A Hill-type pharmacodynamic mathematical model was fitted to the data to characterize the effect.\n\nBactericidal activity for daptomycin was achieved and occurred in a concentration-dependent manner against both
hemB mutants and their parental strains. Against strains with normal phenotype, bactericidal activity was achieved rapidly, within 2 h at concentrations >= 16 times the MIC, while against SCVs, bactericidal activity was achieved within 6 h at concentrations 3-Methyladenine mw >= 16 times the MIC. Against both hemB mutants, daptomycin maintained bactericidal activity at 24 h, with similar profiles of killing activity when compared with their parental strains.\n\nDaptomycin achieved bactericidal activity against S. aureus hemB mutants and parenteral isolates. Daptomycin represents a potential therapeutic option for infections caused by S. aureus strains displaying the SCV phenotype and additional studies are warranted.”
“Purpose: Liproxstatin-1 mouse The mTOR pathway is thought to be a central regulator of proliferation and survival of cells. Rapamycin and its analogs are undergoing clinical trials in patients with epithelial ovarian cancer. This study aimed to assess the potential to use rapamycin and anticancer agents in combination for first- and second-line chemotherapy to treat ovarian cancer.\n\nExperimental Design: We used six ovarian serous adenocarcinoma cell lines (KF, KOC-2S, SHIN-3, SK-OV-3, TU-OS-3,
and TU-OS-4) in this study. We treated the cells with rapamycin and anticancer agents, then assessed cell viability, apoptosis, and the expression of protein in apoptotic pathways and molecules downstream of the mTOR signaling pathways. We also investigated the effect of these drug combinations on survival in nude mouse xenograft models.\n\nResults: Synergistic effects were observed in five cell lines from the combination of etoposide and rapamycin. However, we observed antagonistic effects when rapamycin was combined with gemcitabine, cisplatin, or paclitaxel on more than two cell lines. Rapamycin dramatically enhanced apoptosis induced by etoposide and the expression of cleaved caspase 9. This effect was associated with upregulation of phosphorylated c-Jun and downregulation of Bcl-xL. The synergistic interaction of rapamycin and etoposide was lower when the c-Jun pathway was suppressed by a c-Jun N-terminal kinase inhibitor (SP600125).