New insights into the physicochemical effects of ammonia/peroxide bleaching of hair and Sepia melanins.

Chemically unaltered melanosomes from black hair were isolated using a mild enzymatic procedure reported by Novellino et al. involving sequential treatment of a homogenized hair sample with different protease enzymes. Time-dependent fluorescence studies show, under identical conditions, that the rate of bleaching upon NH3/H2O2 treatment of hair melanosomes is twice that of Sepia melanosomes.

Story understanding and counterfactual reasoning.

D. Kahneman and A. Tversky (1982), in a seminal study on counterfactual reasoning, claimed empirical support for a simulation heuristic wherein ease of converting unusual conditions determines their selection as causes over normal conditions.

Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial.

Objective: To evaluate the efficacy and tolerability of 2 widely used topical alpha-hydroxy acids at low concentrations, 8% glycolic acid and 8% lactic (L-isoform) acid creams, in the treatment of photodamaged skin.

Design: A single-center, 22-week, double-blind, vehicle-controlled, randomized clinical trial assessed the overall severity of photodamage on the faces and forearms of volunteers, based on 7 individual clinical components of cutaneous photodamage.

Setting: The study was performed in an outpatient clinical research unit at the Massachusetts General Hospital, Boston.

Purification, antibody production, and partial amino acid sequence of the 58-kDa acetaminophen-binding liver proteins.

Immunochemical analysis of electrophoretically resolved liver proteins from mice administered hepatotoxic doses of acetaminophen has identified two proteins of 44 and 58 kDa as major targets for acetaminophen arylation. In the present study the 58-kDa acetaminophen-binding protein (58-ABP) was purified from mouse liver cytosol by gel permeation chromatography, preparative isoelectric focusing, and polyacrylamide gel electrophoresis. The acetaminophen adducts were visualized on immunoblots using affinity-purified anti-acetaminophen antibodies after each step of the purification.

A comparison of proteins S-thiolated by glutathione to those arylated by acetaminophen.

This study was designed to evaluate whether the same proteins that irreversibly bind reactive electrophiles of drugs also bind glutathione (GSH) under oxidative conditions. Specifically, proteins that can be arylated by acetaminophen were compared to those that form glutathione-protein mixed disulfides (PSSG) after incubation with diamide. Data are presented which suggest that both GSH and acetaminophen bind to a subset of N-ethylmaleimide (NEM)-reactive protein thiols.