Toxicology Commons^™

Fatty Acids And Mercury In Seventy Seven Species Of Commercially Available Finfish In The United States, Dennis P. Cladis

Open Access Theses

Finfish are consumed across the United States and constitute an important part of the American diet. However, seafood consumption can be a tenuous topic, with supporters highlighting the health benefits of eicosapentaenoic acid (EPA, C20:5n3) and docosahexaenoic acid (DHA, C22:6n3) and opponents emphasizing the neurotoxicity of methylmercury. Because all fish contain varying amounts of EPA, DHA, and methylmercury, the need for clear and unbiased information is essential to alleviate the confusion experienced by many consumers and empower them to make informed decisions regarding seafood consumption. As the market changes and more fish originate from aquaculture sources, where diets are controlled, …

Pharmaceuticals And Personal Care Products: Emerging Contaminants In Aquatic Ecosystems, Jenny E. Zenobio

Open Access Theses

In recent years, the presence of pharmaceuticals and personal care products (PPCPs) in aquatic systems has led to research on their fate and effects. PPCPs have been found in mixture in wastewater effluents, surface, ground, and drinking water at low concentrations from areas of intense urbanization. Although adverse effects to human health from the current environmental concentrations are unlikely, the impacts to ecological receptors are not clear. We performed field and laboratory studies to quantify and evaluate effects of PPCPs on fish. First, a field study was conducted at the Baca National Wildlife Refuge, Colorado (2010-2012) because a portion of …

An Lnvestigation Using Saccharornyces Cereylslae During Growth With Haloperidol On Different Carbon Sources, Elizabeth Garza

Honors Program Theses and Research Projects

Haloperidol is a first generation antipsychotic that is used to treat symptoms of psychosis in patients affected by schizophrenia. This class of antipsychotics is associated with neurological side effects. On the other hand, atypical antipsychotics, such as Clozapine, are associated with metabolic side effects. Ln order to better understand the metabolic basis for the different side effects, we compared the two classes of antipsychotics. Yeast was grown in the presence of Haloperidol on both fermentable and non fermentable carbon sources at concentrations of 0 uM, 1 uM, 5 uM, and 10 uM. The resultant cell viability and the reactive oxygen …

Environews #7, Richard Philp

Data and Test Instruments

Artificial sweeteners in rivers, arsenic underground, gutting of environmental protection laws are topics discussed.

The Characterization Of Pb2+ Toxicity In Rat Neural Development: An Assessment Of Pb2+ Effects On The Gaba Shift In Neural Networks And Implications For Learning And Memory Disruption, Lorenz Simon Neuwirth

Dissertations, Theses, and Capstone Projects

The toxic effects of Pb2+ on the developing rat nervous system has been investigated to assess early developmental GABAergic disruption and its implications with altering inhibitory learning and memory. This goal was achieved using a multi-systems approach: blood lead levels (clinical physiology), qRT-PCR (molecular genetics), brain and primary neuronal culture immunology (immunohistochemical and cellular approaches), physiological cellular components (synaptosomes and protein expression) and finally through learning and memory assessment with GABA mimetic drug manipulations in the intact animal (behavioral pharmacology). The influence of a 956ppm Pb2+ gestational diet (i.e. from birth to sacrifice) resulted in pup mean blood lead levels …

Subthreshold Toxic Effects Of Atrazine And Three Degradates On Behavior In Procambarus Clarkii, Carol B. Starkey

Theses, Dissertations and Capstones

Atrazine is among the most heavily applied pesticides worldwide, and recent evidence suggests that it may be unsafe at environmental levels. It is a known endocrine disruptor and a suggested neurotoxin. The US EPA Maximum Contaminant Level (MCL) is 3 μg/L for human ingestion and 200 μg/L for limited human exposure. Several environmentally persistent degradates have been identified, including deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HA). No MCLs have been established for these degradates, although some are suggested toxins. Thus, there remains concern for the risk associated with the presence of atrazine and its degradates in the environment. Currently little …

Re: Pierce Et Al. Diacetyl And 2,3-Pentanedione Exposures Associated With Cigarette Smoking: Implications For Risk Assessment Of Food And Flavoring Workers Crit Rev Toxicol, 2014; 44(5): 420-435, Muge Akpinar-Elci, Omur Cinar Elci

Center for Global Health Publications

We were greatly dismayed by Pierce et al.’ s report on the associations between exposure to Diacetyl and 2,3-pentanedione and cigarette smoking (Pierce et al. 2014). It stated that “ Diacetyl and 2,3-pentanedione exposures from cigarette smoking far exceed occupational exposures for most food/flavoring workers who smoke. ” Based on this finding, the authors suggested that “ previous claims of a significant exposure – response relationship between diacetyl inhalation and respiratory disease in food/flavoring workers were confounded because none of the investigations considered or quantified the non-occupational diacetyl exposure from cigarette smoke, yet all the cohorts evaluated had considerable smoking …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …