Paper Session I-A - Benchmarking: A Tool For Sharing and Cooperation

Kennedy Space Center, AmericaÕs gateway to the universe, leads the world in preparing and launching missions from earth to the frontiers of space. NASAÕs mission is to advance and communicate scientific knowledge and understanding; explore, use, and develop space; and research, develop, and transfer aerospace technologies. Like any private or public organization, NASA and its contractors are faced with the challenge of performing work better, faster, and cheaper, while maintaining world-class levels of safety and quality. To meet this challenge, the KSC team is using benchmarking as one tool to achieve the goal of improving the bottom-line. Benchmarking is a disciplined approach for comparing and measuring work processes against best-in-class organizations. One outcome of performing a benchmarking study is the identification of best practices that enable superior performance. These best practices can then be adapted and incorporated to achieve improvements in cost, quality, schedule, and cycle time

Hepatic P450 Enzyme Activity, Tissue Morphology and Histology of Mink (Mustela vison) Exposed to Polychlorinated Dibenzofurans

Dose- and time-dependent effects of environmentally relevant concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ) of 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or a mixture of these two congeners on hepatic P450 enzyme activity and tissue morphology, including jaw histology, of adult ranch mink were determined under controlled conditions. Adult female ranch mink were fed either TCDF (0.98, 3.8, or 20 ng TEQTCDF/kg bw/day) or PeCDF (0.62, 2.2, or 9.5 ng TEQPeCDF/kg bw/day), or a mixture of TCDF and PeCDF (4.1 ng TEQTCDF/kg bw/day and 2.8 ng TEQPeCDF/kg bw/day, respectively) for 180 days. Doses used in this study were approximately eight times greater than those reported in a parallel field study. Activities of the cytochrome P450 1A enzymes, ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-deethylase (MROD) were significantly greater in livers of mink exposed to TCDF, PeCDF, and a mixture of the two congeners; however, there were no significant histological or morphological effects observed. It was determined that EROD and MROD activity can be used as sensitive biomarkers of exposure to PeCDF and TCDF in adult female mink; however, under the conditions of this study, the response of EROD/MROD induction occurred at doses that were less than those required to cause histological or morphological changes