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Pharmacology, Toxicology and Environmental Health Commons™

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Toxicology

2000

Articles 1 - 6 of 6

Full-Text Articles in Pharmacology, Toxicology and Environmental Health

The Toxicology Of Aluminum In The Brain: A Review, Robert A. Yokel Oct 2000

The Toxicology Of Aluminum In The Brain: A Review, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Aluminum is environmentally ubiquitous, providing human exposure. Usual human exposure is primarily dietary. The potential for significant Al absorption from the nasal cavity and direct distribution into the brain should be further investigated. Decreased renal function increases human risk of Al-induced accumulation and toxicity. Brain Al entry from blood may involve transferrin-receptor mediated endocytosis and a more rapid process transporting small molecular weight Al species. There appears to be Al efflux from the brain, probably as Al citrate. There is prolonged retention of a fraction of Al that enters the brain, suggesting the potential for accumulation with repeated exposure. Al …

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Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning Feb 2000

Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning

Department of Biological Sciences Publications

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.

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A Computationally Based Identification Algorithm For Estrogen Receptor Ligands: Part 2. Evaluation Of A Herα Binding Affinity Model, Steven P. Bradbury, O. G. Mekenyan, V. Kamenska, P. K. Schmieder, G. T. Ankley Jan 2000

A Computationally Based Identification Algorithm For Estrogen Receptor Ligands: Part 2. Evaluation Of A Herα Binding Affinity Model, Steven P. Bradbury, O. G. Mekenyan, V. Kamenska, P. K. Schmieder, G. T. Ankley

Steven P. Bradbury

The objective of this study was to evaluate the capability of an expert system described in the previous paper (S. Bradbury et al., Toxicol. Sci. 58, 253–269) to identify the potential for chemicals to act as ligands of mammalian estrogen receptors (ERs). The basis of the expert system was a structure activity relationship (SAR) model, based on relative binding affinity (RBA) values for steroidal and nonsteroidal chemicals derived from human ERa (hERa) competitive binding assays. The expert system enables categorization of chemicals into (RBA ranges of < 0.1, 0.1 to 1, 1 to 10, 10 to 100, and >150% relative to 17b-estradiol. In the current analysis, the algorithm was evaluated with respect …

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A Computationally Based Identification Algorithm For Estrogen Receptor Ligands: Part 1. Predicting Herα Binding Affinity, Steven P. Bradbury, V. Kamenska, P. Schmieder, G. Ankley, O. Mekenyan Jan 2000

A Computationally Based Identification Algorithm For Estrogen Receptor Ligands: Part 1. Predicting Herα Binding Affinity, Steven P. Bradbury, V. Kamenska, P. Schmieder, G. Ankley, O. Mekenyan

Steven P. Bradbury

The common reactivity pattern (COREPA) approach is a 3-dimensional, quantitative structure activity relationship (3-D QSAR) technique that permits identification and quantification of specific global and local stereoelectronic characteristics associated with a chemical’s biological activity. It goes beyond conventional 3-D QSAR approaches by incorporating dynamic chemical conformational flexibility in ligand-receptor interactions. The approach provides flexibility in screening chemical data sets in that it helps establish criteria for identifying false positives and false negatives, and is not dependent upon a predetermined and specified toxicophore or an alignment of conformers to a lead compound. The algorithm was recently used to screen chemical data …

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Effects Of Polychlorinated Biphenyl Exposure On Development And Sexual Differentiation In Ranid Tadpoles, Mary J. Rybitski Jan 2000

Effects Of Polychlorinated Biphenyl Exposure On Development And Sexual Differentiation In Ranid Tadpoles, Mary J. Rybitski

Dissertations, Theses, and Masters Projects

The effects of AroclorRTM1242 exposure on developing amphibians were examined by exposing southern leopard frogs, Rana sphenocephala, to a contaminated diet throughout the larval period. Treatment groups consisted of an untreated control, a solvent control, 17beta-estradiol, and three PCB doses (10, 100, and 1000 mug/g). PCB accumulation and biotransformation were examined. Effects of PCB exposure on metamorphosis and sexual differentiation were assessed. PCB accumulation was not statistically different between the egg masses. Levels of PCBs in the tissues differed in a dose related manner. Within treatments, body weight appeared to be the major factor correlated with PCB concentration. Congener patterns …

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Ambient Toxicity Of Water Samples From Four Locations In The Elizabeth River : A Comparison Of Species Sensitivities, Morris H. Roberts, Peter F. De Lisle Jan 2000

Ambient Toxicity Of Water Samples From Four Locations In The Elizabeth River : A Comparison Of Species Sensitivities, Morris H. Roberts, Peter F. De Lisle

Reports

In the present study, the objective was to evaluate four species for relative sensitivity when challenged with ambient water from four locations in the Elizabeth River, ranging from locations considered to be free of toxicity to an area known to have copper concentrations that exceeded water quality standards in past sampling.

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