Toxicology Commons^™

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …

Effects Of Crude Oil On Tumor Suppressor P53 Polymorphisms In Laboratory-Exposed Atlantic Killifish, Fundulus Heteroclitus, Allison Margaret Nadler

Seton Hall University Dissertations and Theses (ETDs)

Polycyclic aromatic hydrocarbons (PAHs), constituents of crude oil, are implicated as a potent source of adverse toxicological effects on living organisms. To model the effects of PAHs in response to environmental oil spill disasters a species of killifish (Fundulus heteroclitus) was captured and exposed to crude oil in a laboratory-controlled setting. Over a period of 7 days, fish were dosed with crude oil by gavage, culled, and organs were harvested for analysis. Excitation-emission matrix spectroscopy (EEMS) of gall bladder tissue homogenates was used to verify exposure. Effects of PAHs on the p53 gene were evaluated as an indicator …

Identification And Quantification Of Cyanide And Its Metabolites In Lemur Urine, Jeremy Peralta

Student Theses

Cyanide is a chemical compound that contains the monovalent groups of carbon and nitrogen. This substance is considered a rapidly acting deadly chemical. However, some animals such as lemurs consume food products that are known to contain elevated levels of cyanide without major consequences. The mechanism by which the lemur can handle this high exposure to cyanide is unknown. In this study, we developed and validated two analytical methods for the determination of cyanide and two metabolites, thiocyanate and 2-aminothiazoline-4-carboxylic acid (ATCA) in lemur urine. The method was applied to 47 authentic lemur urine samples collected from 4 different species …

Molecularly Imprinted Polymers Synthesized As Adsorbents For Ergot Alkaloids: Characterization And In Vitro And Ex Vivo Assessment Of Effects On Ergot Alkaloid Bioavailability, Manoj B. Kudupoje

Theses and Dissertations--Animal and Food Sciences

Alkaloid toxicities negatively impact livestock health and production and are of serious economic concern to animal industries. To date, few strategies have been developed to evaluate alkaloid levels in feed or to counteract alkaloid toxicities. The present research evaluated the applicability of imprinting technology to synthesize polymers that have potential to interact with ergot alkaloids and therefore reduce their bioavailability in the GIT. The studies also evaluated applicability of synthesized polymers for use in the ruminal environment using an in vitro ruminal fermentation model, and for the ability to ameliorate vasoconstriction using ex vivo myographic evaluations.

In the first experiment, …