Metabolism and accumulation of the lipophilic deoxynucleoside analogs elacytarabine and CP-4126

Cytarabine (ara-C) and gemcitabine (dFdC) are commonly used anticancer drugs, which depend on the equilibrative (ENT) and concentrative-nucleoside-transporters to enter the cell. To bypass transport-related drug resistance, lipophilic derivatives elacytarabine (CP-4055), ara-C-5′elaidic-acid-ester, and CP-4126, (CO 1.01) gemcitabine-5′elaidic-acid-ester, were investigated for the entry into the cell, distribution, metabolism and retention. The leukemic CEM-cell-line and its deoxycytidine-kinase deficient variant (CEM/dCK-) were exposed for 30 and 60 min to the radiolabeled drugs; followed by culture in drug-free medium in order to determine drug retention in the cell. The cellular fractions were analyzed with thin-layer-chromatography and HPLC. Elacytarabine and CP-4126 were converted to the parent compounds both inside and outside the cell (35–45%). The ENT-inhibitor dipyridamole did not affect their uptake or retention. Inside the cell Elacytarabine and CP-4126 predominantly localized in the membrane and cytosolic fraction, leading to a long retention after removal of the medium. In contrast, in cells exposed to the parent drugs ara-C and dFdC, intracellular drug concentration increased during exposure but decreased to undetectable levels after drug removal. In the dCK- cell line, no metabolism was observed. The concentrations of ara-CTP and dFdCTP reached a peak at the end of the incubation with the drugs, and decreased after drug removal; peak levels of dFdCTP were 35 times higher than ara-CTP and was retained better. In contrast, after exposure to elacytarabine or CP-4126, ara-CTP and dFdCTP levels continued to increase not only during exposure but also during 120 min after removal of the elacytarabine and CP-4126. Levels of ara-CTP and dFdCTP were higher than after exposure to the parent drugs. In conclusion, the lipophilic derivatives elacytarabine and CP-4126 showed a nucleoside-transporter independent uptake, with long retention of the active nucleotides. These lipophilic nucleoside analogues are new chemical entities suitable for novel clinical applications

Development and preliminary evaluation of a telephone-based coping skills training intervention for survivors of acute lung injury and their informal caregivers

PURPOSE: Survivors of acute lung injury (ALI) and their informal caregivers have difficulty coping with the physical and emotional challenges of recovery from critical illness. We aimed to develop and pilot test a telephone-based coping skills training intervention for this population. METHODS: 58 participants were enrolled overall. 21 patients and 23 caregivers participated in a cross-sectional study to assess coping and its association with psychological distress. This also informed the development of an ALI coping skills training intervention in an iterative process involving content and methodological experts. The intervention was then evaluated in 7 patients and 7 caregivers in an uncontrolled, prospective, pre-post study. Outcomes included acceptability, feasibility, and symptoms of psychological distress measured with the Hospital Anxiety and Depression Scale (HADS) and Post-Traumatic Symptom Scale (PTSS). RESULTS: Survivors and their caregivers used adaptive coping infrequently, a pattern that was strongly associated with psychological distress. These findings informed the development of a 12-session intervention for acquiring, applying, and maintaining coping skills. In the evaluation phase, participants completed 77 (92%) of a possible 84 telephone sessions and all (100%) reported that the intervention’s usefulness in their daily routine. Mean change scores reflecting improvements in the HADS (7.8 units) and PTSS (10.3 units) were associated with adaptive coping (r=0.50–0.70) and high self-efficacy (r=0.67–0.79). CONCLUSIONS: A novel telephone-based coping skills training intervention was acceptable, feasible, and may have been associated with a reduction in psychological distress among survivors of ALI and their informal caregivers. A randomized trial is needed to evaluate the intervention