Toxicology Commons^™

The Development Of Liquid Chromatography Mass Spectrometry Methods For The Analysis Of Cyanobacterial Toxins In Environmental Freshwaters, Brian Anthony Dineen

Theses

Cyanobacteria, also known as blue-green algae, are a common component of many freshwater and marine ecosystems and have a potential to produce several different classes of biotoxins. The most common class of cyanobacterial toxins are the microcystins (MCs) and cylindrospermopsins (CYLs). MCs are cyclic heptapeptides that display potent hepatotoxicity and are tumour promoters. CYLs are alkaloids that are cytotoxic and can cause illness and display hepatotoxic effects in animals and humans. Worldwide, these toxins have caused fatal poisonings to animals, birds and fish. Several incidents of human intoxications have been reported and the presence of these toxins in environmental waters …

Investigation Of Pyrrolizidine Alkaloids In Foods Using Liquid Chromatography Mass Spectrometry, Caroline Griffin

Theses

Pyrrolizidine Alkaloids (PAs) are known plant toxins which can cause hepatic veno-occlusive disease (HVOD) in both humans and livestock when ingested. Although PAs are primarily known for their hepatotoxicity they also induce genotoxicity, carcinogenicity and pneumotoxicity. PAs are consumed through plants as food, for medicinal purposes, or as contaminants of agricultural crops. Aside from ingesting the plants directly PA exposure may occur through the consumption of honey produced by bees that visit PA-containing plants or by drinking milk produced by animals that have consumed PA-containing plants. Possible PA contamination in our food chain is a potential health risk.

To assess …

Epigenetic Changes After Prenatal Environmental Tobacco Smoke Exposure And Asthma, Sonja Christensen

Graduate Student Theses, Dissertations, & Professional Papers

Allergic asthma affects over 300 million people worldwide. Multiple factors have been shown to alter an individuals' susceptibility to this allergic airway disease such as exposure to polycyclic aromatic hydrocarbons (PAHs), endotoxin, and environmental tobacco smoke (ETS). Prenatal exposure to these contaminants, especially ETS, has been shown to increase risk for an individuals’ asthma risk, however, the mechanism by which this happens is still unknown. Epigenetic alterations, particularly DNA methylation patterns, have been introduced as a proposed mechanism. The goals of this project were to use a house dust mite (HDM) murine model of asthma to determine the methylation alterations …

An Environmental Toxic Model Of Parkinson's Disease: The Fruit Fly, Jennene Lyda

Graduate Student Theses, Dissertations, & Professional Papers

Parkinson’s disease (PD) is the second most common neurodegenerative disorder with no known specific cause; although genetic risk factors and/or environmental exposure are thought to be involved. The etiology of PD is currently unknown, although the combination of non-genetic components such as environmental exposures, the accumulation of exposure, and gene-environment interactions are thought to play a major role. However, despite this knowledge it is important to develop better models that parallel PD pathophysiology to further understand the mechanisms underlying dopaminergic neuron (DaN) damage. The use of mammalian models to study the degenerative processes in PD has been the most common …

Species - Dependent Cardiac And Motor Responses To Cholinergic Stimulation In Daphnia Pulex And Daphnia Magna, Bryan James Hannan

Wayne State University Theses

The role of acetylcholine (ACh) in regulating the activity of the heart and `feeding current' driven by the beating thoracic appendages of Daphnia pulex and Daphnia magna was evaluated using acetylcholinesterase inhibitors (AChE-I) and muscarinic receptor agonists. Single animals, tethered to a stainless steel pin, were tested in a watertight aquatic chamber that allowed free movement of appendages and swimming antennae. Heart contraction rate and the rate of thoracic appendage beating were quantified optically by measuring fluctuating changes in light-intensity caused by movement. Physostigmine, neostigmine, oxotremorine, pilocarpine as well as nicotine were used to study ACh and AChE. Atropine was …

Study Of Protective Role Of Cytochrome P450s In Inflammatory Bowel Disease Using Cprlow Mouse Model, Xiaoyu Fan

Legacy Theses & Dissertations (2009 - 2024)

Glucocorticoids (GCs) are potent regulatory factors for inflammation. The synthesis of GCs involves several cytochrome P450 enzymes, such as mitochondrial CYP11A1, CYP11B1, and microsomal CYP21. Previous studies have indicated that the GCs, including those released from adrenal glands, and those synthesized in extra-adrenal tissues, such as intestine, exert inhibitory effects on inflammatory bowel disease (IBD). In a previous study using an intestinal epithelium (IE)-specific P450 reductase (CPR) knockout (IE-Cpr-null) mouse model, the results suggested that the intestinal P450s had a protective role in DSS-induced acute colitis. In this study, using a hypomorphic CPR mouse model (Cprlow), which presents a global …

Impact Of Zinc Oxide Nanoparticles On Green Pea Plant & Seed Quality And Effects On Physiological Traits Of Green Peas, Corn, And Zucchini By Silver Nanoparticles, Arnab Mukherjee

Open Access Theses & Dissertations

The production and use of numerous engineered nanomaterials (ENMs) have increased exponentially over the past decade. Nanoparticles (NPs), ENMs possessing diameter between 1-100 nm, (NPs), are widely used in many applications. Worldwide consumption of NPs has increased their possible release into the environment. This, in turn, has elevated the extent of the potential impacts of NP exposure to living and non-living organisms. This is why the assessment of the impact of NPs on different environmental components, especially on plants, the producer in the food web, has become a very important aspect of nano-ecotoxicology. However, studies focusing on phytotoxicity and effects …

The Role Of Surface Chemistry In The Toxicity Of Manufactured Cerium Dioxide Nanomaterials To Caenorhabditis Elegans, Emily Kay Oostveen

Theses and Dissertations--Plant and Soil Sciences

Manufactured CeO₂ nanomaterials (CeO₂-MNMs) are used for a wide variety of applications including diesel fuel additives and chemical/mechanical planarization media. To test the effects of CeO₂-MNM surface coating charge on to model organism Caenorhabditis elegans, we synthesized 4 nm CeO₂ with cationic (DEAE-), anionic (CM-), and neutral (DEX) coatings. In L3 nematodes exposed for 24 hours, DEAE-CeO₂ induced lethality at lower concentrations than CM- or DEX-CeO₂. Feeding slightly decreased CeO₂ toxicity, regardless of coating. In L2 nematodes exposed for 48 hours with feeding, DEAE-CeO₂ caused lethality at the …

Bystander Effects Due To Neutrons, And Low-Dose Hyper-Radiosensitivity To Gamma Rays In Human Cells Using Cytogenetics, Isheeta Seth

Wayne State University Dissertations

Chapter 2:

Micronuclei have been used extensively in studies as an easily-evaluated indicator of DNA damage but little is known about their association with other types of damage such as nucleoplasmic bridges and nuclear buds. Radiation-induced clastogenic events were evaluated via the cytokinesis-block micronucleus assay in two normal human lymphoblastoid cell lines exposed to neutrons or gamma radiation. Micronuclei, nucleoplasmic bridges and nuclear buds were enumerated by recording the coincident presence of these endpoints within individual cells, and the associations among these three endpoints were evaluated for all treatment conditions. The common odds ratios for micronuclei and nucleoplasmic bridges were …

Epoxy Resin Monomers With Reduced Skin Sensitizing Potency, Niamh F. O'Boyle, Ida B. Niklasson, Ali R. Tehrani-Bagda, Tamara Delaine, Krister Holmberg, Kristina Luthman, Ann-Therese Karlberg

Articles

Epoxy resin monomers, including diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to cause widespread contact allergy. This research describes a number of alternative epoxy resin monomers, designed with the aim of reducing the skin sensitizing potency whilst maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, assessed for skin sensitizing potency using the in vivo murine local lymph node assay, and tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. All the novel epoxy resin monomers had decreased skin …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

Concern-Driven Integrated Toxicity Testing Strategies For Nanomaterials - Report Of The Nanosafety Cluster Working Group 10, Hugh Byrne, Agnes G. Oomen, Peter M.J. Bos, Teresa F. Fernandes, Kerstin Hund-Rinke, Diana Boraschi, Karin Aschberger, Stefania Gottardo, Frank Von Der Kammer, Dana Kühnel, Danail Hristozov, Antonio Marcomini, Lucia Migliore

Articles

Bringing together topic-related European Union-(EU)-funded projects, the so-called “NanoSafety Cluster” aims at identifying key areas for further research on risk assessment procedures for nanomaterials (NM). The outcome of NanoSafety Cluster Working Group 10, this commentary presents a vision for concern-driven integrated approaches for the (eco-)toxicological testing and assessment (IATA) of NM. Such approaches should start out by determining concerns, i.e. specific information needs for a given NM based on realistic exposure scenarios. Recognized concerns can be addressed in a set of tiers using standardized protocols for NM preparation and testing. Tier 1 includes determining physico-chemical properties, non-testing (e.g. structure …

Effects Of Salinity And Dissolved Organic Matter On Cu Toxicity To Americamysis Bahia In Estuarine Environments, Rabia Nasir

Theses and Dissertations (Comprehensive)

As salinity increases the geochemical speciation of Cu is altered as a result of organic/inorganic complexation/competition. Such salinity changes may further challenge the osmoregulatory capabilities of euryhaline organisms. This chemical-biological interaction complicates the understanding of the impacts of Cu in estuarine waters. Dissolved organic matter (DOM) has been widely established to be an important modifier of Cu toxicity in freshwaters however its effectiveness in modulating Cu toxicity across the range of salinities that occur in estuarine conditions has not been studied in a systematic manner. Site to site differences in DOM quality with respect to the potential for toxicity mitigation …

Distribution And Elimination Of 3-Trifluoromethyl-4-Nitrophenol (Tfm) By Sea Lamprey (Petromyzon Marinus) And Non-Target, Rainbow Trout (Oncorhynchus Mykiss) And Lake Sturgeon (Acipenser Fulvescens), Michael W. Le Clair

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), has been highly successful in the control of sea lamprey (Petromyzon marinus) populations in the Great Lakes. Treatments with TFM involve applying it to streams, where it targets larval sea lamprey which live burrowed in the stream substrate. While the toxic mechanism of TFM has been elucidated, and its effects on sea lamprey described, its effects on non-target fish species such as rainbow trout (Oncorhynchus mykiss) and lake sturgeon (Acipenser fulvescens) are not as well understood. The present work demonstrated that rainbow trout show a great capacity to detoxify the lampricide using glucuronidation, when exposed to …

The Establishment Of A Fibroblastic Cell Line From Yellow Perch (Perca Flavescens) And Its Potential Applications In Toxicology, Katelin W. Spiteri

Theses and Dissertations (Comprehensive)

This thesis describes the establishment, characterization and potential toxicological applications of YPF5, a yellow perch cell line. YPF5 is a fibroblastic cell line derived from the caudal fin of yellow perch. This cell line has been maintained for over 2 years. Cultures have been passaged over 60 times, and successfully cryopreserved and thawed. YPF5 is grown at room temperature in Leibovitz-15 (L-15) media, supplemented with 10% fetal bovine serum and 3% penicillin-streptomycin. The origin of YPF5 has been confirmed as Perca flavescens through “DNA Barcoding” and reaffirmed through Karyotyping (2n = 48) as per literature reported karyology for percidae including …

Toxic And Repellent Effects Of Pyrethroids Used In Orchards On The Honey Bee, Apis Mellifera L. (Hymenoptera: Apidae), Erin M. Ingram

Department of Entomology: Dissertations, Theses, and Student Research

Managed honey bee colonies provide valuable pollination services and are rented by fruit orchards to improve fruit quality and yield. The placement of colonies in this agricultural setting increases the possibility of exposure to pyrethroids used for broad-spectrum pest control in orchards. Although highly toxic to bees, pyrethroids are believed to pose a relatively low hazard due to their low application rates in the field as well as their contact repellent properties. Previous studies have noted a decrease in foraging visits following pyrethroid application possibly preventing bees from acquiring a lethal dose in the field.

This research quantified behaviors associated …

Importance Of Clinical Toxicology Teaching And Its Impact In Improving, Nadeem Ullah Khan, Jabeen Fayyaz, Uzma R. Khan, Asher Feroze

Department of Emergency Medicine

Objective: To assess the impact of a one-day clinical toxicology workshop in improving knowledge.
Methods: A one-day clinical toxicology workshop was conducted as a pre-conference workshop of the Annual Emergency Medicine Conference at the Aga Khan University Hospital, Karachi, in April 2012. The course was composed of poisoning-related common clinical scenarios. The pre-test and post-test understanding was used to assess the impact of the course in improving knowledge. The participants also evaluated the workshop as a whole thorough written evaluation forms. SPSS 19 was ued for statistical analysis of the data.
Result: There were 22 participants in the course. The …

High Dose, Variable Length, N-Acetylcysteine (Hinac) Therapy For Late-Presenting Acetaminophen Poisoning, Jessica K. Eygnor Do, Suprina Dorai Md, Philip W. Moore Do, J Ward Donovan Md, Keith K. Burkhart Md

Department of Emergency Medicine

No abstract provided.

Immunological And Reproductive Health Assessment In Herring Gulls And Black-Crowned Night Herons In The Hudson-Raritan Estuary, Keith A. Grasman, Kathy R. Echols, Thomas M. May, Paul H. Peterman

University Faculty Publications and Creative Works

Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in …

Atrazine And Nitrate In Public Drinking Water Supplies And Non-Hodgkin Lymphoma In Nebraska, Usa, Martha G. Rhoades, Jane L. Meza, Cheryl L. Beseler, Patrick J. Shea, Andy Kahle, Julie M. Vose, Kent M. Eskridge, Roy F. Spalding

School of Natural Resources: Faculty Publications

A secondary analysis of 1999–2002 Nebraska case-control data was conducted to assess the risk of non-Hodgkin lymphoma (NHL) associated with exposure to nitrate- and atrazine-contaminated drinking water. Water chemistry data were collected and weighted by well contribution and proximity of residence to water supply, followed by logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). We found no association between NHL risk and exposure to drinking water containing atrazine or nitrate alone. Risk associated with the interaction of nitrate and atrazine in drinking water was elevated (OR, 2.5; CI, 1.0–6.2). Risk of indolent B-cell lymphoma was higher …