%0 Generic %D 2016 %T Toxicity in zebrafish of complex polycyclic aromatic hydrocarbon mixtures exposed to terrestrially-appropriate UV-radiation. %A Peter D Hoffman %A Lane G Tidwell %A Kim A Anderson %B Society for Environmental Toxicology and Chemistry 2016 Annual Meeting, Orlando, Florida, USA %8 11/2016 %G eng %0 Journal Article %J Environ Sci Pollut Res Int %D 2016 %T Transport stability of pesticides and PAHs sequestered in polyethylene passive sampling devices. %A Carey E Donald %A Elie, Marc R %A Brian W Smith %A Peter D Hoffman %A Kim A Anderson %X

Research using low-density polyethylene (LDPE) passive samplers has steadily increased over the past two decades. However, such research efforts remain hampered because of strict guidelines, requiring that these samplers be quickly transported in airtight metal or glass containers or foil wrapped on ice. We investigate the transport stability of model pesticides and polycyclic aromatic hydrocarbons (PAHs) with varying physicochemical properties using polytetrafluoroethylene (PTFE) bags instead. Transport scenarios were simulated with transport times up to 14 days with temperatures ranging between -20 and 35 °C. Our findings show that concentrations of all model compounds examined were stable for all transport conditions tested, with mean recoveries ranging from 88 to 113 %. Furthermore, PTFE bags proved beneficial as reusable, lightweight, low-volume, low-cost alternatives to conventional containers. This documentation of stability will allow for more flexible transportation of LDPE passive samplers in an expanding range of research applications while maintaining experimental rigor.

%B Environ Sci Pollut Res Int %8 03/2016 %G eng %R 10.1007/s11356-016-6453-3 %0 Journal Article %J Environ Mol Mutagen %D 2006 %T Testing excision models for responses of mismatch-repair systems to UV photoproducts in DNA. %A Wang, Huxian %A Peter D Hoffman %A Christopher W Lawrence %A John B Hays %K Animals %K Base Pair Mismatch %K CHO Cells %K Cricetinae %K Cricetulus %K DNA %K DNA Repair %K HeLa Cells %K Humans %K Plasmids %K Pyrimidine Dimers %K Ultraviolet Rays %X

Mismatch-repair (MMR) systems correct DNA replication errors and respond to a variety of DNA lesions. Previous observations that MMR antagonizes UV mutagenesis, and that the mismatch-recognition protein heterodimer MSH2*MSH6 (MutSalpha) selectively binds DNA containing "mismatched" photoproducts (T[CPD]T/AG, T[6-4]T/AG) but not "matched" photoproducts (T[CPD]T/AA, T[6-4]T/AA), suggested that mismatched photoproducts would provoke MMR excision similar to mismatched bases. Excision of incorrect nucleotides inserted opposite template photoproducts might then prevent UV-induced mutation. We tested T[CPD]T/AG DNA, in a sequence context in which it is bound substantially by hMutSalpha and in three other contexts, for stimulation of 3' MMR excision in mammalian nuclear extracts. T[CPD]T/AG was inactive in HeLa extracts, or in extracts deficient in the photoproduct-binding proteins DDB or XPC* hHR23B, arguing against interference from the nucleotide excision repair pathway. Prior incubation with hMutSalpha and MLH2.PMS2 (hMutLalpha) did not increase excision relative to homoduplex controls. T[6-4]T/AG also failed to provoke excision. T/G, C/A, and T/T substrates, even though bound by hMutSalpha no better than T[CPD]T/AG substrates, efficiently provoked excision. Even a substrate containing three T[CPD]T/AG photoproducts (in different contexts) did not significantly provoke excision. Thus, MMR may suppress UV mutagenesis by non-excisive mechanisms.

%B Environ Mol Mutagen %V 47 %P 296-306 %8 2006 May %G eng %N 4 %R 10.1002/em.20206