The effect of stress on the antioxidative potential of serum: implications for Alzheimer's disease.

There is growing consensus in the literature that oxidation status is increased in Alzheimer's disease (AD), and that antioxidant supplementation as prevention or treatment strategy should be investigated further. In the present study the total antioxidant status (TAS) was found to be highly significantly lower in 22 AD patients (p < 0.0001) than in 22 age- and gender matched non-demented controls.

Population screening for isoniazid acetylator phenotype.

Purpose: To establish a useful method for acetylator phenotypification and therapeutic drug monitoring of patients receiving isoniazid.

Methods: Sixty patients with uncomplicated pulmonary tuberculosis were given a 5-mg/kg oral dose of isoniazid each. Plasma concentrations of isoniazid and its metabolite, acetyl-isoniazid, were determined by HPLC analyses at various post-dose times.

Trimodality of isoniazid elimination: phenotype and genotype in patients with tuberculosis.

The study was undertaken to show that polymorphic isoniazid elimination in humans is trimodal; that the acetylator genotype and eliminator phenotype of the individual patient are concordant; and that the differences in the pharmacokinetic parameters of fast, intermediate, and slow eliminator subgroups are statistically significant. Sixty adult patients of both sexes and of mixed race with tuberculosis participated in the trial. The apparent elimination rate constant (k, h(-1)) and the area under the isoniazid concentration-time curve (AUC, mg/L/h), over the interval 2 to 6 h after oral isoniazid were determined in all patients; NAT2 allele composition was determined in 47 patients.

Free radical scavenging effects of melatonin and serotonin: possible mechanism.

Melatonin has been reported to be a potent free radical scavenger, but the mechanism by which it protects membranes from lipid peroxidation is poorly understood. The present study addresses this problem by comparing the free radical scavenging properties of melatonin and serotonin, two indoles with similar structure, but differing solubilities. Both serotonin and melatonin significantly prevented lipid peroxidation of platelet membranes.