Urine test for the assessment of smoking status.

A simple, quick and inexpensive test for smoking status would be useful in a variety of settings. The non-polar barbituric acid derivative 1,3-dibutyl-2-thiobarbituric acid (DBTB) is described as a novel derivatisation reagent for nicotine and its metabolites in the König reaction to assess smoking status. The relative performance of qualitative methods for assessing smoking status using DBTB and the previously employed derivatisation reagent 1,3-diethyl-2-thiobarbituric acid (DETB), as well as quantitatively-based methods for determining 'total nicotine metabolites' (TNMs) using these two reagents, were evaluated against a cotinine-based radioimmunoassay (RIA) as the 'gold standard'. Clinical sensitivity and specificity for all the approaches studied were in excess of 94%. Simple qualitative assessment by eye was superior to quantitatively-based measures of smoking status. Correlation between estimation of nicotine metabolites using DBTB, DETB and RIA were good. The most efficient and convenient method to distinguish between smokers and non-smokers was the simple qualitative method using the more lipophilic reagent DBTB.

Effects of nimesulide and its metabolites or manufacturing intermediates on the viability and growth of the human hepatoma HepG2 cell line.

Hepatitis and fulminant hepatic failure have, infrequently, been associated with nimesulide. To establish if nimesulide or its analogues have direct cytotoxic activity on liver cells, experiments were undertaken to investigate the effects of nimesulide and its principal metabolites and production intermediates on the viability and growth of the human hepatoma cell line, HepG2, in vitro. The parent drug, metabolites or production intermediates as well as formulations of nimesulide were incubated for 6-48 hr with HepG2 cells and the extent of toxicity determined using the mitochondrial selective redox dye 3-4,5-dimethylthazol-2-yl)-2,4-diphenyl tetrazolium bromide (MTT). The results showed that there was no appreciable cytotoxic activity exhibited by nimesulide and its principle metabolites or production intermediates on HepG2 cells.