17 research outputs found
Natural forest regeneration in abandoned sugarcane fields in northeastern Brazil: floristic changes
Organophosphate triesters and selected metabolites enhance binding of thyroxine to human transthyretin in vitro
The toxicological properties of organophosphate (OP) triesters that are used as flame retardants and plasticizers are currently not well understood, though increasing evidence suggests they can affect the thyroid system. Perturbation of thyroid hormone (TH) transport is one mechanism of action that may affect thyroid function. The present study applied an in vitro competitive protein binding assay with thyroxine (T4) and human transthyretin (hTTR) transport protein to determine the potential for the OP triesters, TDCIPP (tris(1,3-dichloro-2-propyl) phosphate), TBOEP (tris(butoxyethyl) phosphate), TEP (triethyl phosphate), TPHP (triphenyl phosphate), p-OH-TPHP (para-hydroxy triphenyl phosphate), and the OP diester DPHP (diphenyl phosphate), to competitively displace T4 from hTTR. Enhancement of T4 binding to hTTR, rather than the hypothesized competition, was observed for the six OP esters and in a concentration-dependent manner. For example, T4-hTTR binding was significantly increased at concentrations of TBOEP as low as 64 nM, and up to 184% of controls at 5000 nM. A plausible explanation of these results, which to our knowledg
Spatial distributions of polychlorinated biphenyls, polybrominated diphenyl ethers, tetrabromobisphenol A and bisphenol A in Lake Erie sediment
Long-term consequences of variation in timing and manner of fry introduction on juvenile Atlantic salmon ( Salmo salar
Vapor-liquid equilibria and excess molar properties of MTBE + methanol and + ethanol mixtures
Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 1. Accumulation patterns in harbour seals and harbour porpoises
Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are two representative top
predator species of the North Sea ecosystem. The median values of sum of 21 polychlorinated biphenyl
(PCB) congeners and sum of 10 polybrominated diphenyl ether (PBDE) congeners were 23.1 mg/g lipid
weight (lw) and 0.33 mg/g lw in blubber of harbour seals (n ¼ 28) and 12.4 mg/g lw and 0.76 mg/g lw in
blubber of harbour porpoises (n¼ 35), respectively. For both species, the highest PCB concentrations
were observed in adult males indicating bioaccumulation. On the contrary, the highest PBDE concentrations
were measured in juveniles, likely due to better-developed metabolic capacities with age in
adults. A higher contribution of lower chlorinated and non-persistent congeners, such as CB 52, CB 95, CB
101, and CB 149, together with higher contributions of other PBDE congeners than BDE 47, indicated that
harbour porpoises are unable to metabolize these compounds. Harbour seals showed a higher ability to
metabolize PCBs and PBDEs