Aromatic DNA adducts in brain tumors by 32P-postlabeling analysis

Sampling and analytical method development and hand wipe measurements of dermal exposures to polycyclic aromatic hydrocarbons

This article describes the laboratory assessment of a hand and surface wipe sampling method for polycyclic aromatic hydrocarbons (PAHs). The analytical method employed extraction of the wipe samples into dimethyl sulfoxide (DMSO) and high-performance liquid chromatography (HPLC) flourometric detection of pyrene, a predominant PAH in used gasoline engine oils (UGEO). Recovery of pyrene was evaluated for two different sampling media by first contaminating the hands of a small number of volunteers with UGEO, followed by applying a small amount of corn oil to the palms, and by wiping the skin with a Whatman cellulostic filter paper or a polyester fabric wipe (i.e., Alpha wipes). In summary, using either Whatman or Alpha wipes, the mean recovery of pyrene from the UGEO that was applied to the hands and contained within three consecutive wipes was 69% and 54%, respectively. However, the relative recovery of the first to second wipe was on average 47% and 75% for the two media, respectively. These results indicate that the Alpha wipes were more efficient at recovering pyrene in the first wipe but less efficient overall when all three consecutive samples were included. Even though this sampling was performed in a controlled laboratory environment, the minimum and maximum amount of pyrene recovered in the individual composite samples using either method spanned a range of twofold. Overall, intra-and interpersonal variability, as measured by coefficient of variation, were 22% and 19%, respectively, and were not statistically different by type of media used. This method was used in a pilot field survey to sample the hands of 18 automotive repair technicians and 18 office workers. Detectable amounts of pyrene (>0.2 microg/sample) were found on the hands of 61% and 0% of these two groups, respectively, with the highest measured quantity equal to 1.06 microg. Samples from the upper surfaces of automobile motors were generally low to nondetectable (<0.027 microg/sample), while the median value of 0.047 mkcrlg/50 cm(2)(CV = 160%) and up to 0.640 microg were found on the drip pans.

Non-destructive analysis of the protein conformational structure of human pituitary adenomas using reflectance FT-IR microspectroscopy

Reflectance Fourier-transform infrared microspectroscopy was used to determine the secondary structure and composition of the different human pituitary adenomas. Non-functioning pituitary adenomas exhibited similar protein secondary structure and conformational composition, but active pituitary adenomas revealed different behavior. The differences in secondary structure for the different human pituitary adenomas might possibly be due to the different protein conformations of the proliferated adenoma tissues and various hormones shared.