Changes in calculated glomerular filtration rate (GFR) from baseline to five yr were analyzed in relation to risk factors among renal transplant recipients. At three months after transplantation (baseline), 430 eligible patients receiving sirolimus (SRL), cyclosporine (CsA), and steroids (ST) were randomly assigned (1:1) to continue SRL-CsA-ST or have CsA withdrawn and SRL trough levels increased (SRL-ST group). For each risk factor, changes from baseline were compared within each treatment using a t-test and between treatments using ANCOVA.
View Article and Find Full Text PDFIn sediments that contain iron monosulfide, cadmium, nickel, lead, zinc, and silver(I) form insoluble metal sulfides that lower the metal ion activity in the sediment-pore water system, thereby reducing toxicity. However, metal sulfides are susceptible to oxidation by molecular oxygen resulting in metal solubilization. To better understand the sources and sinks of metal sulfides in sediments, iron monsulfide-rich freshwater sediments were spiked with cadmium, nickel, lead, zinc, or silver(I) and placed into cylindrical cores with an overlying layer of oxygen-saturated water.
View Article and Find Full Text PDFEnviron Toxicol Chem
November 2005
Ionic silver is toxic to aquatic organisms at low concentrations. However, complexation to binding sites on natural organic matter has been shown to reduce silver toxicity. Research indicates that there is a need to develop reliable methods for characterizing silver binding at very low silver ion concentrations where strong binding sites have a significant influence on silver speciation.
View Article and Find Full Text PDFEnviron Sci Technol
December 2005
Arsenic contamination in aquatic systems is a worldwide concern. Understanding the redox cycling of arsenic in sediments is critical in evaluating the fate of arsenic in aquatic environments and in developing sediment quality guidelines. The direct oxidation of inorganic trivalent arsenic, As(III), by dissolved molecular oxygen has been studied and found to be quite slow.
View Article and Find Full Text PDFThe Challenger mechanism for the methylation of arsenic is a repeating sequence of a two-electron reduction of pentavalent arsenic As(V) species to trivalent arsenic As(III) species followed by a methylation-oxidation reaction forming the successive methyl As(V) species. This unusual oxidation-reduction sequence prompted an examination of the thermodynamics of these reactions. Quantum chemical methods are employed to estimate the thermodynamic parameters for the methyl arsenic species.
View Article and Find Full Text PDFActivated glial cells (microglia and astroglia) in the spinal cord play a major role in mediating enhanced pain states by releasing proinflammatory cytokines and other substances thought to facilitate pain transmission. In the present study, we report that intrathecal administration of minocycline, a selective inhibitor of microglial cell activation, inhibits low threshold mechanical allodynia, as measured by the von Frey test, in two models of pain facilitation. In a rat model of neuropathic pain induced by sciatic nerve inflammation (sciatic inflammatory neuropathy, SIN), minocycline delayed the induction of allodynia in both acute and persistent paradigms.
View Article and Find Full Text PDFLack of donors has led to a worldwide increase in commercial kidney transplantation programs where recipients acquire kidneys either from executed prisoners or live non-related donors. Commercial transplantation is prohibited by legislation in Australia. Our centres have had 16 patients who have travelled overseas to receive a commercial kidney transplant; five have subsequently died.
View Article and Find Full Text PDFSoluble arsenic(III)-sulfide complexes (thioarsenites) play a significant role in the chemistry of arsenic in reducing, sulfidic environments at circumneutral pH. Chemical equilibrium calculations using thioarsenite thermodynamic data from the literature indicate that the formation of a dithioarsenite complex, AsS(OH)(SH)(-1), reduces the concentration of the uncomplexed inorganic As(III) species present (defined sigma H3AsO3, where sigma H3AsO3 = AsO3(-3) + HAsO3(-2) + H2AsO3(-1) + H3AsO3). With enough sulfide present, soluble As(III) is dominated by this complex.
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