The contributing role of glove powder in sensitization to natural rubber latex (NRL) proteins has been well documented in laboratory studies and through clinical evaluations. However, the quantitative relationship of the respiratory and topical exposures in the sensitization process remains unknown because the relative levels of protein on the glove powders in relation to the total levels of protein on NRL gloves have not been determined. In NRL allergens--Hev b 1, Hev b 3, Hev b 5, and Hev b 6.02--on randomly selected surgical and examination NRL gloves. We also examined the binding pattern of the four allergens to several glove powders that showed a different affinity to NRL proteins. The level of powder-bound protein was determined by the ELISA Inhibition Assay (ASTM D6499 standard method). Two cross-linked corn starch powders, one sample of cooking corn starch and one oat starch sample, were exposed to ammoniated (AL) or nonammoniated (NAL) raw NRL protein extracts. The levels of individual allergens were determined using the NRL allergen kit. In the NRL glove extracts we observed a wide range in the total allergen levels and a great diversity in the proportion of the four allergens. On the other hand, the evaluated starches had similar ratios of four individual allergens, regardless of the differences in their total allergen levels. The exposure of starches to NRL proteins with different allergen profiles did not affect the allergen ratio. All samples demonstrated a selective affinity for binding Hev b 1 and Hev b 5 allergens and a lesser affinity for the Hev b 6.02 allergen. Allergen Hev b 6.02 made up about 60% of the total allergen in the NAL extract, but only 12-30% of Hev b 6.02 was bound to starches. In contrast, there was only 3-7% of Hev b 1 allergen in the NAL extract, but powders had 35-45% of Hev b 1. These findings indicate that allergenic properties of NRL gloves and respective glove powders may be different.

No abstract

No abstract

A method for determination of two relevant sphingoid precursors such as sphingosine and sphinganine and the corresponding conjugates sphingosine 1-phosphate and sphinganine 1-phosphate in human urine and serum is here presented. The method is characterized by a solid- phase extraction step with in situ derivatization of the sphingolipids in the eluate (o-phthaldialdehyde derivatives) to obtain fluorescent compounds. In this way, sample preparation was completely performed in a single automated step by means of a lab-on-valve system. Derivatized analytes were injected into a liquid chromatography system operating at micro regime and detected by laser-induced fluorescence. For determination of sphingoid phosphates, they were enzymatically converted to free sphingoids to obtain stable fluorescent derivatives. The detection limits were in the range 4.2-10.2 ng mL(-1) for serum and 0.56-1.36 ng mL(-1) for urine, with repeatability ranging from 3.9% to 6.2% expressed as relative standard deviation. The method was validated by direct infusion tandem mass spectrometry in multiple reaction monitoring to compare results provided by analysis of biofluids and to confirm the identity of the target compounds. Sensitivity and precision were better than or similar to those provided by the confirmatory method. The automation of sample preparation enables to scale-down this step and improves precision by minimization of human intervention, being thus suitable for clinical analysis.