Toxicology Commons^™

A Compromised Liver Alters Polychlorinated Biphenyl-Mediated Toxicity, Banrida Wahlang, Jordan T. Perkins, Michael C. Petriello, Jessie B. Hoffman, Arnold J. Stromberg, Bernhard Hennig

Superfund Research Center Faculty Publications

Exposure to environmental toxicants namely polychlorinated biphenyls (PCBs) is correlated with multiple health disorders including liver and cardiovascular diseases. The liver is important for both xenobiotic and endobiotic metabolism. However, the responses of an injured liver to subsequent environmental insults has not been investigated. The current study aims to evaluate the role of a compromised liver in PCB-induced toxicity and define the implications on overall body homeostasis. Male C57Bl/6 mice were fed either an amino acid control diet (CD) or a methionine-choline deficient diet (MCD) during the 12-week study. Mice were subsequently exposed to either PCB126 (4.9 mg/kg) or the …

An Open-Sourced Statistical Application For Identifying Complex Toxicological Interactions Of Environmental Pollutants, Jordan T. Perkins, Michael C. Petriello, Li Xu, Arnold J. Stromberg, Bernhard Hennig

Superfund Research Center Faculty Publications

The rising number of chemicals that humans are exposed to on a daily basis, as well as advances in biomonitoring and detection technologies have highlighted the diversity of individual exposure profiles (complex body burdens). To address this, the toxicological sciences have begun to shift away from examining toxic agents or stressors individually to focusing on more complex models with multiple agents or stressors present. Literature on interactions between chemicals is fairly limited in comparison with dose-response studies on individual toxicants, which is largely due to experimental and statistical challenges. Experimental designs capable of identifying these complex interactions are often avoided …

Mechanisms Of Thymic Toxicity Induced By Environmentally Relevant Concentrations Of Arsenic, Huan Xu

Biomedical Sciences ETDs

Arsenic, a ubiquitous environmental contaminant, is known to cause immunotoxicity. However, the mechanisms of arsenic induced immunotoxicity are still not clear. Arsenite (As⁺³), the trivalent inorganic form of arsenic, was found to increase DNA damage and inhibit PARP activity in thymus cells at 50 nM in vitro. Oxidative stress and double strand breaks (DSBs) formation occurred in thymus cells exposed to As⁺³ at 500 nM. The genotoxicity was found to be related to As⁺³ exporter expressions and reversed by zinc supplement. IL-7 signaling, the critical cytokine signal for the early DN thymic T cell proliferation, …

Chloroquine-Inducible Par-4 Secretion Is Essential For Tumor Cell Apoptosis And Inhibition Of Metastasis, Ravshan Burikhanov, Nikhil Hebbar, Sunil K. Noothi, Nidhi Shukla, James Sledziona, Nathália Araujo, Meghana Kudrimoti, Qing Jun Wang, David S. Watt, Danny R. Welch, Jodi Maranchie, Akihiro Harada, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

The induction of tumor suppressor proteins capable of cancer cell apoptosis represents an attractive option for the re-purposing of existing drugs. We report that the anti-malarial drug, chloroquine (CQ), is a robust inducer of Par-4 secretion from normal cells in mice and cancer patients in a clinical trial. CQ-inducible Par-4 secretion triggers paracrine apoptosis of cancer cells and also inhibits metastatic tumor growth. CQ induces Par-4 secretion via the classical secretory pathway that requires the activation of p53. Mechanistically, p53 directly induces Rab8b, a GTPase essential for vesicle transport of Par-4 to the plasma membrane prior to secretion. Our findings …

Tenofovir Induced Nephrotoxicity: A Mechanistic Study, Rachel A. Murphy

Theses, Dissertations and Capstones

Tenofovir (TFV) is a reverse transcriptase inhibitor that is approved by the United States Food and Drug Administration (FDA) to treat HIV and chronic Hepatitis B. It has a long half-life, allowing for once a day dosing and is effective in treatment of both naive and experienced patients. It is administered orally as tenofovir disoproxil fumarate (TDF) and is deesterified in plasma to the active drug TFV. However, renal impairment is associated with its use; TFV can induce decreased glomerular filtration rate (GFR) and free calcitriol, renal failure, and Fanconi Syndrome. The exact mechanism of toxicity currently remains unknown, largely …

Establishing Environmental Variability In The Toxins Produced By A Single Strain Of Prymnesium Parvum, Amy Parsons-White

Theses, Dissertations and Capstones

Prymnesium parvum (P. parvum) is a toxin producing haptophyte that has spread globally over the past 100 years. The algae, initially a marine organism, has moved inland to less saline waters. In addition, there is variability in the efficacy of the toxins produced from bloom to bloom. Variation between strains has been suggested as the reason for bloom differences; however, environmental variability within a single strain must first be established. Here, a single strain of P. parvum was cultured at three environmentally relevant salinities, 6psu, 13psu, and 35psu. Three different environmental shocks, decreased temperature, raised pH, and addition of specific …

4-Methylcyclohexanemethanol Acute Toxicity To Daphnia And Its Effects On General Esterase And Glutathione S-Transferase Activity In Fathead Minnows, Rachel Clark, Jared Lewis, Jeehoon Jung, Benjamin Thornton

Research in Biology

In 2014, 10,000 gallons of crude MCHM spilled into the Elk River in West Virginia. Due to a paucity of information about the toxicity of this chemical prior to the spill, our research aimed to verify the published 48-h EC₅₀ for Daphnia magna (Daphnia) examine the effects of MCHM on two enzyme detoxification systems, general esterase and glutathione S-transferase, in Pimephales promelas (Fathead Minnow). We used pure MCHM instead of the crude form used in Eastman’s toxicity tests because the composition of crude MCHM is variable. The EC₅₀ we obtained for pure MCHM did not differ significantly from …

Evaluation Of Childhood Exposure To Lead In Community Water Systems In Maine, Nicholas Flavin

Muskie School Capstones and Dissertations

The concentration of lead in Maine’s public drinking water was evaluated from 4,700 first-draw water samples collected from 358 Maine Community Water systems. Samples collected from 2012-2015 were obtained by request from the Maine Center for Disease Control and Prevention’s (MeCDC)’s Drinking Water Program.

Exposure and physiological uptake of lead can be mathematically modelled or predicted based on the amount of lead in “background” sources of contaminated media such as soil, dust, water, air or dietary items; the better the characterization of lead in these media, the better the exposure predictions. To assess childhood lead exposure, EPA recommends using the …

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, …

The Effects Of The Hiv-1 Tat Protein And Morphine On The Structure And Function Of The Hippocampal Ca1 Subfield, William D. Marks

Theses and Dissertations

HIV is capable of causing a set of neurological diseases collectively termed the HIV Associated Neurocognitive Disorders (HAND). Worsening pathology is observed in HIV+ individuals who use opioid drugs. Memory problems are often observed in HAND, implicating HIV pathology in the hippocampus, and are also known to be exacerbated by morphine use. HIV-1 Tat was demonstrated to reduce spatial memory performance in multiple tasks, and individual subsets of CA1 interneurons were found to be selectively vulnerable to the effects of Tat, notably nNOS+/NPY- interneurons of the pyramidal layer and stratum radiatum, PV+ neurons of the pyramidal layer, and SST+ neurons …

Aluminum And Phthalates In Calcium Gluconate: Contribution From Glass And Plastic Packaging, Robert A. Yokel, Jason M. Unrine

Pharmaceutical Sciences Faculty Publications

Introduction: Aluminum contamination of parenteral nutrition solutions has been documented for three decades. It can result in elevated blood, bone, and whole body aluminum levels associated with neurotoxicity, reduced bone mass and mineral content, and perhaps hepatotoxicity. The primary aluminum source among parenteral nutrition components is glass-packaged calcium gluconate, in which aluminum concentration the past three decades has averaged~ 4000 [mu]g/L, compared to < 200 [mu]g/L in plastic container-packaged calcium gluconate. A concern about plastic packaging is leaching of plasticizers, including phthalates, which have the potential to cause endocrine (male reproductive system) disruption and neurotoxicity.

Methods: Aluminum was quantified in samples collected periodically over more than two years from three calcium gluconate sources used to prepare parenteral nutrition solutions; two packaged in glass (from France and the US) and one in plastic …

Organ-Specific Contribution Of P450 Enzymes To Bioactivation And Acute Respiratory Tract Toxicity Of Naphthalene, Nataliia Kovalchuk

Legacy Theses & Dissertations (2009 - 2024)

Naphthalene (NA) is an omnipresent air pollutant and respiratory toxicant and a possible human lung carcinogen. NA induces cytotoxicity in airways following bioactivation by CYP (P450) enzymes. The overall goal of this study was to examine the relative contributions of hepatic and pulmonary CYPs to bioactivation, disposition and NA-induced pneumotoxicity in vivo. Substantial differences in the expression and enzymatic activity of P450s occur in various organs in human populations, which could modify susceptibility to NA-induced airway damage. The central hypothesis for this study was that NA has the potential to cause lung toxicity in humans and that the metabolism of …

Biomarkers And Metabolic Mechanisms Of Tobacco Smoke-Induced Lung Disease, Matthew Alan Hartog

Legacy Theses & Dissertations (2009 - 2024)

The overall goal of the research conducted in this dissertation is to determine the role of cytochrome (CYP) P450-mediated xenobiotic bioactivation in the development of tobacco smoke-induced lung toxicity. The central hypothesis of this work is that CYP-mediated bioactivation of specific tobacco smoke constituents is an important contributor to the generation of tobacco smoke-induced lung inflammation and injury. The specific aims are 1) to demonstrate that CYP-mediated metabolism contributes to the onset of lung inflammation following tobacco smoke inhalation; 2) to demonstrate that specific tobacco smoke constituents undergo CYP-mediated bioactivation in vivo; 3) to demonstrate that CYP-mediated bioactivation of tobacco …

Understanding The Genotoxicity Of Silver Nanoparticles And The Chemoprevention Of Pomegranate Extract, Sameera Nallanthighal

Legacy Theses & Dissertations (2009 - 2024)

The use of silver nanoparticles (AgNPs) in a wide variety of consumer products (i.e. toothpastes, food containers, dietary supplements and garments) for their antimicrobial properties can lead to potential oral exposure in humans. To enhance their stability, AgNPs are coated with capping agents such as citrate and polyvinylpyrrolidone (PVP). Despite the lack of significant general toxicity based on hematology, blood chemistry and histology evaluations, the potential genotoxic effects of AgNPs cannot be ruled out and have to be addressed. Studies examining the genotoxic risks of AgNPs are needed because genotoxicity is a strong indicator of cancer risk. Here we examined …

Effects Of Antibiotic Treatment On The Expression Of Hepatic And Intestinal Cytochrome P450, Bruno Pereira De Carvalho

Legacy Theses & Dissertations (2009 - 2024)

Expression of metabolic enzymes Cytochrome P450 (CYP) is highly affected by drugs, diseases, age and gender. The Intestinal microflora has been suggested to play a role in regulating CYP expression and antibiotic treatments would lead to changes in level and composition of microbiota in mouse gut. This study aims to analyze CYP expression changes in the liver and small intestine resulted from the reduction of intestinal microflora by antibiotics. Impacts on bile acid signaling were also analyzed for a better comprehension of the mechanisms involved in this modulation. Female C57BL/6J mice (9- to 13-week old) were treated with ampicillin (AMP) …

Endocrine-Disrupting Properties Of Pharmaceuticals And Personal Care Products (Ppcps): An Evaluation Using Aquatic Model Organisms, Manahil Monshi

Wayne State University Theses

Thousands of chemicals have introduced into the environment as a result of human activity since the industrial revolution, and the U.S. Government Accountability Office has estimated that as many as 1,500 new chemical entities are synthesized each year ("Key Issues: Toxic Chemicals - High Risk Issue," 2017). Many of these chemicals are now found in surface water and ground water and can have detrimental effects on environmental health and on human health. This anthropogenic contamination has resulted in the labeling of the diverse array of chemicals found in water, which are not routinely monitored or regulated, as contaminants of emerging …

Mercury Accumulation And Effects In The Brain Of Atlantic Sharpnose Sharks (Rhiszoprionodon Terranovae), Samantha L. Ehnert

UNF Graduate Theses and Dissertations

Sharks often bioaccumulate mercury (Hg) concentrations in their muscle to levels that threaten the health of human consumers. However, few published studies have examined if the high Hg levels seen in shark muscle also occur in the shark brain, or if Hg accumulation affects shark neurophysiology. Therefore, this study examined if shark brains accumulate significant levels of Hg, if Hg accumulation occurs in certain subcomponents of the brain, and if Hg accumulation is associated with oxidative stress effects on the shark central nervous system, with special focus on the Atlantic sharpnose shark (Rhizoprionodon terraenovae). Sharks were collected along …

Effects Of Chromium On Mouse Splenic T Lymphocytes And Effects Of Ethanol Exposure During Early Neurodevelopment On Behaviors In Mice, Lu Dai

Theses and Dissertations--Toxicology and Cancer Biology

The dissertation consists of three major projects with the focus on the immunotoxicity of chromium and the behavior disorders caused by early ETOH exposure respectively.

Hexavalent chromium [Cr(VI)] is widely used in various industrial processes and has been recognized as a carcinogen. As the first line of host defense system, the immune system can be a primary target of Cr(VI). T cell population represents a major arm of the immune system that plays a critical role in host anti-tumor immunity. Dysfunction of T cells compromises host anti-tumor immunity resulting in oncogenesis. Using mouse splenic T cells as an in vitro …

Poison In Pink, Sydney V. Cook

Graduate Student Theses, Dissertations, & Professional Papers

Humans slather, spray, mist, and cleanse their bodies with personal care products like lotion, hairspray, cologne, and shampoo every day. Our cupboards are stocked full of them, but few of us understand what is in those jars and bottles. We trust that if it’s on the shelf at the store, it’s safe. However, this is not always the case, and many personal care products contain chemicals that are harmful to human and environmental health.

My multi-disciplinary Environmental Studies thesis project combines evidenced-based research, interviews, nonfiction narrative, and science communication to create part of a book manuscript intended to educate general …

Immunotherapy Against Drugs Of Abuse, Gianna Raimondi (Class Of 2017)

Writing Across the Curriculum

Current treatments for drug addiction involve classical pharmacological therapy, involving the use of competitive or noncompetitive agonists (full, partial, or inverse) and antagonists. Drugs of abuse enter the brain after crossing the blood-brain barrier rapidly and binding to the proper receptor(s). They are able to do so because they are small and lipid soluble, and produce reinforcing effects by increasing levels of dopamine in brain areas associated with reward. This occurs in specific systems associated with addiction. In the mesolimbic system, neuron cell bodies originate in the ventral tegmental area (VTA) and project to the nucleus accumbens (NAc), amygdala, hippocampus, …