Molecular basis for the synergistic interaction of adriamycin with the formaldehyde-releasing prodrug pivaloyloxymethyl butyrate (AN-9)

The interaction of Adriamycin and pivaloyloxymethyl butyrate (AN-9) was investigated in IMR-32 neuroblastoma and MCF-7 breast adenocarcinoma cells. Adriamycin is a widely used anticancer drug, whereas AN-9 is an anticancer agent presently undergoing Phase II clinical trials. The anticancer activity of AN-9 has been attributed to its ability to act as a butyric acid prodrug, although it also releases formaldehyde and pivalic acid. Adriamycin and AN-9 in combination display synergy when exposed simultaneously to cells or when AN-9 treatment is up to 18 h after Adriamycin administration. However, the reverse order of addition results in antagonism. These interactions have been established using cell viability assays and classical isobologram analysis. To understand the molecular basis of this synergy, the relative levels of Adriamycin-DNA adducts were determined using various treatment combinations. Levels of Adriamycin-DNA adducts were enhanced when treatment combinations known to be synergistic were used and were diminished using those treatments known to be antagonistic. The relative timing of the addition of Adriamycin and AN-9 was critical, with a 20-fold enhancement of Adriamycin-DNA adducts occurring when AN-9 was administered 2 h after the exposure of cells to Adriamycin. The enhanced levels of these adducts and the accompanying decreased cell viability were directly related to the esterase-dependent release of formaldehyde from AN-9, providing evidence for the formaldehyde-mediated activation of Adriamycin.

Weight-bearing manipulation: a neglected area of medical science relevant to piano playing and overuse syndrome

Functional anatomy and physiology have naturally attended mainly to those functions which occur most commonly in everyday life. Piano playing is a more specialized area, where functions arise which have so far been neglected in medical science. These functions are here described by a pianist (IH) in the hope that medical researchers will respond to fill the gaps. The importance of this lies not only in the understanding of skilled manipulative activity but also in the avoidance of overuse syndrome (OUS) or repetitive strain injury (RSI).