Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 2: Potential coral effects.

Coral reefs are in decline worldwide due to anthropogenic stressors including reductions in water and substratum quality. Dredging results in the mobilization of sediments, which can stress and kill corals via increasing turbidity, tissue damage and burial. The Particle Tracking Model (PTM) was applied to predict the potential impacts of dredging-associated sediment exposure on the coral reef ecosystems of Apra Harbor, Guam.

Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 1: Sediment exposure modeling.

Model studies were conducted to investigate the potential coral reef sediment exposure from dredging associated with proposed development of a deepwater wharf in Apra Harbor, Guam. The Particle Tracking Model (PTM) was applied to quantify the exposure of coral reefs to material suspended by the dredging operations at two alternative sites. Key PTM features include the flexible capability of continuous multiple releases of sediment parcels, control of parcel/substrate interaction, and the ability to efficiently track vast numbers of parcels.

An HPLC method for the indirect quantification of a quinone adduct of the drug paroxetine.

An HPLC method has been developed which enables the quantification of low levels of a catechol derivative and a quinone adduct of paroxetine in the presence of excess drug substance. Due to its inherent instability, the paroxetine quinone adduct is not available as a pure compound so that an indirect method was developed for its quantification. This procedure is based on the assumption that one molecule of the catechol (or more precisely the corresponding 1,2-benzoquinone) reacts with one molecule of paroxetine to produce one molecule of paroxetine quinone adduct.

Protein expression changes in the Sprague Dawley rat liver proteome following administration of peroxisome proliferator activated receptor alpha and gamma ligands.

Peroxisome proliferator activated receptors (PPARs) are members of the nuclear receptor superfamily and are intimately involved in lipid metabolism and energy homeostasis. Activation of these receptors in rodents can lead to hepatomegaly and ultimately hepatic carcinogenesis although the mechanisms by which these processes occur are poorly understood. To further our understanding of these processes and to discriminate between different PPAR mediated signalling pathways, a proteomic approach has been undertaken to identify changes in protein expression patterns in Sprague Dawley rat liver following dosing with a PPARalpha agonist (Wyeth 14643), a PPARgamma agonist (Troglitazone) and a compound with mixed PPARalpha/gamma agonist activity (SB-219994).

Protein expression analysis of drug-mediated hepatotoxicity in the Sprague-Dawley rat.

This study has investigated the protein changes in rat liver elicited by a group of model hepatotoxicants, methapyrilene, cyproterone acetate and dexamethasone and offers a compelling argument in support of the use of two-dimensional polyacrylamide gel electrophoresis and mass spectrometry for the identification of compound specific biomarkers. The different treatments caused distinct changes to the rat liver proteome. Many of the protein changes could be associated with the known pharmacological and toxicological mechanisms of action of these drugs, whereas for other proteins, the rationale behind the alterations was less obvious.