Ellipticine cytotoxicity to cancer cell lines — a comparative study

Ellipticine is a potent antineoplastic agent exhibiting multiple mechanisms of action. This anticancer agent should be considered a pro-drug, whose pharmacological efficiency and/or genotoxic side effects are dependent on its cytochrome P450 (CYP)- and/or peroxidase-mediated activation to species forming covalent DNA adducts. Ellipticine can also act as an inhibitor or inducer of biotransformation enzymes, thereby modulating its own metabolism leading to its genotoxic and pharmacological effects. Here, a comparison of the toxicity of ellipticine to human breast adenocarcinoma MCF-7 cells, leukemia HL-60 and CCRF-CEM cells, neuroblastoma IMR-32, UKF-NB-3 and UKF-NB-4 cells and U87MG glioblastoma cells and mechanisms of its action to these cells were evaluated. Treatment of all cells tested with ellipticine resulted in inhibition of cell growth and proliferation. This effect was associated with formation of two covalent ellipticine-derived DNA adducts, identical to those formed by 13-hydroxy- and 12-hydroxyellipticine, the ellipticine metabolites generated by CYP and peroxidase enzymes, in MCF-7, HL-60, CCRF-CEM, UKF-NB-3, UKF-NB-4 and U87MG cells, but not in neuroblastoma UKF-NB-3 cells. Therefore, DNA adduct formation in most cancer cell lines tested in this comparative study might be the predominant cause of their sensitivity to ellipticine treatment, whereas other mechanisms of ellipticine action also contribute to its cytotoxicity to neuroblastoma UKF-NB-3 cells

The genetic impact of translocations and habitat fragmentation in chamois (Rupicapra) spp.

The chamois is a useful species with which to investigate the combined genetic impact of habitat fragmentation, over hunting, and translocations. Genetic variation within and between chamois (genus Rupicapra) populations was analyzed i

Meropenem Pharmacokinetics in the Newborn▿

We studied meropenem in 23 pre-term (gestational age, 29 to 36 weeks) and 15 full-term (gestational age, 37 to 42 weeks) neonates. Meropenem doses of 10, 20, and 40 mg/kg were administered as single doses (30-min intravenous infusion) on a random basis. Blood was obtained for determining the meropenem concentration nine times. Each child required other antimicrobials for proven/suspected bacterial infections. Samples were assayed by high-performance liquid chromatography analysis. Population pharmacokinetic parameter values were obtained by employing the BigNPAG program. Model building was performed by the likelihood ratio test. The final model included estimated creatinine clearance (CLcr) (Schwartz formula) and weight (Wt) in the calculation of clearance (meropenem clearance = 0.00112 × CLcr + 0.0925 × Wt + 0.156 liter/hr). The overall fit of the model to the data was good (observed = 1.037 × predicted − 0.096; r2 = 0.977). Given the distributions of estimated creatinine clearance and weight between pre-term and full-term neonates, meropenem clearance was substantially higher in the full-term group. A Monte Carlo simulation was performed using the creatinine clearance and weight distributions for pre-term and full-term populations separately, examining 20- and 40-mg/kg doses, 8- and 12-h dosing intervals, and 0.5-h and 4-h infusion times. The 8-h interval produced robust target attainments (both populations). If more resistant organisms were to be treated (MIC of 4 to 8 mg/liter), the 40-mg/kg dose and a prolonged infusion was favored. Treating clinicians need to balance dose choices for optimizing target attainment against potential toxicity. These findings require validation in clinical circumstances