Clinical evaluation of QT/QTc prolongation and proarrhythmic potential for nonantiarrhythmic drugs: the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use E14 guideline.

Proarrhythmias due to drug-induced QT prolongation are the second most common cause for drug withdrawal and have caused increasing concern. Two new International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines were recently endorsed in which nonclinical (S7B) and clinical (E14) methodologies are discussed and guidance is given to the industry. This commentary describes the key components of the E14 document, the impact of nonclinical testing on the clinical program, the thorough QT study, and the impact of its result on late-stage development.

[Zidovudine. The current status of its evaluation].

3'-azido-3'-deoxythymidine is a thymidine analogue with an in vitro as well as in vivo efficacy towards HIV-mediated infection. Zidovudine exerts its action, following an intracellular three-step phosphorylation, through viral reverse transcriptase inhibition. Its half-life is approximately one hour.

Ultrastructural localization of aluminum in hepatocytes of hemodialyzed patients.

The livers of 7 hemodialyzed patients have been studied by electron microscopy and electron probe X-ray microanalysis. In 6 patients dialyzed for a long time (at least 39 months), aluminum has been detected in high concentrations in phagolysosomes of hepatocytes; in these lysosomes aluminum is associated with phosphorus. In 2 of these 6 patients, a very large number of aluminum inclusion bodies were found inside hepatocytes and this aluminum accumulation was associated with severe ultrastructural lesions of the cells.

[Prevention and treatment of cytomegalovirus infections after graft of allogenic bone marrow].

Cytomegalovirus (CMV) infection is the most frequent cause of lethal infection after bone marrow transplantation. Viremia occurs in 50% of patients seropositive for CMV before transplantation. Interstitial pneumonitis due to CMV occurs in 10% to 20% of patients with 85% mortality.