Influence of slide aging on results of translational research studies using immunohistochemistry.

Several reports have shown that a long delay between cutting sections and immunohistochemical (IHC) staining can decrease the IHC reaction intensity. However, systematic large-scale studies to investigate to what extent this problem may influence the outcome of translational research studies are lacking. In this study, we used a tissue microarray (TMA) approach to investigate the influence of slide age on comparisons between the results of IHC analyses for estrogen receptor (ER), progesterone receptor (PR), cyclin D1, HER2 (HercepTest), and E-cadherin and clinical outcome in a series of 522 breast cancer patients.

Permeation, metabolism and site of action concentration of nicotinic acid derivatives in human skin. Correlation with topical pharmacological effect.

A novel methodology for establishing a pharmacological dose-effect relationship of methyl nicotinate, hexyl nicotinate and nicotinic acid acting as peripheral vasodilators in the skin following topical application is investigated. This methodology involves the estimation of the unbound drug concentration in the aqueous compartment at the site of action in tissue, termed C(*), which was evaluated as the pertinent concentration responsible for the pharmacological effect. Blood capillaries next to the epidermis-dermis boundary were postulated to be the relevant site of action.