Pharmacology, Toxicology and Environmental Health Commons^™

Exocrine Pancreatic Neoplasms In The Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site, John W. Fournie, Wolfgang K. Vogelbein

VIMS Articles

A high prevalence of exocrine pancreatic neoplasms occurred in mummichog, Fundulus heteroclitus, from a creosote-contaminated site in the Elizabeth River, Virginia. A total of 20 neoplasms were found in a group of about 1,300 fish obtained at this site over a 2-yr period. Of 240 fish collected during October 1991, 3.3% had pancreatic neoplasms. Adjusted total lesion prevalence for large adult fish (Size Class III: total length = 75–85 mm; Size Class IV: total length > 85 mm) was 6.7%. Pancreatic neoplasms were not observed in 234 fish collected at this site during May 1991, nor were they found in …

Molecular Toxicology Of Pyrrolizidine Alkaloids, Hea-Young Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pyrrolizidine alkaloids are cytotoxic, carcinogenic, and anti-carcinogenic in vivo and in vitro, and they produce many hazardous effects in humans and animals. Pyrrolizidine alkaloids (PAs) also cross-link with DNA and/or protein. However, whether such cross-linking is important to the toxic action of PAs is not known. In addition, the exact mechanism underlying these DNA cross-links or cytotoxicity is also not clear.

In three separate studies, I characterized the nature of PA-induced DNA cross-links and the relationships between PA structures and cross-linking potency. In the first study (Chapter II), I found that cross-linking potency of PA congeners coincided with their …

Predicting Modes Of Toxic Action From Chemical Structure: An Overview, Steven P. Bradbury

Steven P. Bradbury

In the field of environmental toxicology, and especially aquatic toxicology, quantitative structure activity relationships (QSARs) have developed as scientifically-credible tools for predicting the toxicity of chemicals when little or no empirical data are available. A basic and fundamental understanding of toxicological principles has been considered crucial to the continued acceptance and application of these techniques as biologically relevant. As a consequence, there has been an evolution of QSAR development and application from that of a chemical-class perspective to one that is more consistent with assumptions regarding modes of toxic action. The assessment of a compound’s likely mode of toxic action …

Comparative Toxicity Of Creosote And Creosote Contaminated Sediments, Padma T. Venkatraman

Dissertations, Theses, and Masters Projects

No abstract provided.

An Evaluation Of Benthic Macroinvertebrate Community Structure And Sediment Toxicity In Lake Taylorville, Sanhita Datta

Masters Theses

Sediments act as a "sink" for xenobiotics which can be accumulated by a variety of organisms and thereby enter the food chain contaminating fish, wildlife and humans. Although the chemical nature of these substances can be known by direct chemical analysis of the sediments, the significance of the contaminants and their bioavailability should be determined through bioassay techniques. A survey of the benthic macroinvertebrates of Lake Taylorville, a reservoir in central Illinois which is fed by two rivers that drain a primarily agricultural area, revealed a rather depauperate fauna. Subsequent studies were conducted in order to identify the underlying cause …

Toxicity Resistance In Mummichog (Fundulus Heteroclitus) From A Chemically Contaminated Environment, Cynthia A. H. Williams

Dissertations, Theses, and Masters Projects

No abstract provided.

Investigations Into Cataract Formation In Sciaenid Fish Species From The Elizabeth River, Chesapeake Bay, Virginia, Christopher D. Williams

Dissertations, Theses, and Masters Projects

Cataract formation in the Elizabeth River (ER) has been reported since 1986. Previous studies have concentrated on describing cataract as a function of exposure to polluted sediments, especially polycyclic aromatic hydrocarbons (PAH). These studies, however, have not examined what processes might be involved in fish cataractogenesis. The overall objective of this research was to identify important processes associated with the early development of cataract in feral fish populations. Field studies were used to systematically examine cataract development. Cataract in sciaenids was not associated with previously described cataractogenic factors, but could be linked to contaminated sediments of the ER. Cataract was …

Effects Of Methyl Parathion On The Cellular Immune Responses In Giant Black Tiger Shrimp, Penaeus Monodon, Nantarika. Bodhipaksha

Dissertations, Theses, and Masters Projects

The effects of an organophosphorus pesticide, methyl parathion, on cellular immune defense mechanisms of the giant black tiger shrimp (Penaeus monodon) were studied. Animals were exposed for 96 hours at concentrations equal to, above and below the LC&\sb{lcub}50{rcub}& (3 ppb). Phagocytes were obtained from the heart and circulating hemolymph. Cellular immune responses, including chemotaxis, phagocytosis and the respiratory burst were examined. Chemotactic activity was determined by means of a modified Boyden double chamber technique. There was a dose-dependent decrease in the chemotactic activities of both circulating hemocytes and cardiac phagocytes. Phagocytic activity (percent phagocytosis) was examined by the microscopic enumeration …