Analysis of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB)-releasing DNA adducts in human exfoliated oral mucosa cells by liquid chromatography-electrospray ionization-tandem mass spectrometry.

Quantitation of DNA adducts could provide critical information on the relationship between exposure to tobacco smoke and cancer risk in smokers. In this study, we developed a robust and sensitive liquid chromatography-tandem mass spectrometry method for the analysis of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB)-releasing DNA adducts in human oral cells, a noninvasive source of DNA for biomarker studies. Isolated DNA undergoes acid hydrolysis, after which samples are purified by solid-phase extraction and analyzed by LC-ESI-MS/MS. The developed method was applied to the analysis of samples obtained via collection with a commercial mouthwash from 30 smokers and 15 nonsmokers. In smokers, the levels of HPB-releasing DNA adducts averaged 12.0 pmol HPB/mg DNA (detected in 20 out of 28 samples with quantifiable DNA yield), and in nonsmokers, the levels of adducts averaged 0.23 pmol/mg DNA (detected in 3 out of 15 samples). For the 30 smoking subjects, matching buccal brushings were also analyzed, and HPB-releasing DNA adducts were detected in 24 out of 27 samples with quantifiable DNA yield, averaging 44.7 pmol HPB/mg DNA. The levels of adducts in buccal brushings correlated with those in mouthwash samples of smokers (R = 0.73, p < 0.0001). Potentially, the method can be applied in studies of individual susceptibility to tobacco-induced cancers in humans.

Toxicity of the components of styrene polymers: polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-butadiene-rubber (SBR). Reactants and additives.

The toxicity of the components of styrene polymers, e.g., polystyrene, ABS and SBR, were reviewed with primary focus on the reactive monomers (except styrene) (e.g., acrylonitrile, butadiene) as well as on impurities and solvents such as benzene, hexane and methylethyl ketone, and additives such as phenyl-2-naphthylamine, di-n-butyl phthalate, and a number of peroxide initiators and flame retardants (e.g., 2,3-dibromopropanol, decadibromodiphenyl oxide and antimony trioxide). It is stressed that toxicity data are generally lacking for the majority of additives employed in the production of styrene polymers. Information is also lacking as to the numbers of individuals at potential risk and the extent of their exposure to the large number of additives employed.