Toxicology Commons^™

Genomic Based Environmental Health Assessment: Vieques, Puerto Rico, Valeria Hernandez Talavera

Graduate Doctoral Dissertations

From 1941 to 2003, the United States Navy and North Atlantic Treaty Organization (NATO) used Vieques, Puerto Rico, for military training, which led to long-term pollution from metals, organic chemicals, explosives, and per- and polyfluoroalkyl substances (PFAS). While earlier research found these contaminants in the environment and in living organisms, their combined effects on local ecosystems remain poorly understood.

This dissertation used a Genomic-Based Environmental Health Assessment (GEHA) framework to study the ecological risks from past military pollution in Vieques. The approach combined sediment toxicity tests, chemical analysis, gene expression studies, microbial community analysis, and community-based research. The four main …

Spider Biodiversity And Insecticide Sensitivity Across Active And Restored Cranberry Bogs On Nantucket, Tyler J. Kulak

Graduate Masters Theses

Spiders are one of the most diverse groups of organisms on the planet with over 53,000 species described as of 2026. They provide a suite of ecosystem services including their regulation of problematic pests in agricultural systems, appearing in high biomasses across a breadth of ecological niches. While beneficial as pest regulators, they are also susceptible to the same management techniques as pest organisms and are especially vulnerable to chemical control. Cranberry production in Massachusetts likely benefits from spider ecosystem services, but diversity research on spiders in these systems is limited. This study compares the diversity of spider populations from …

Evaluation Of Pulmonary Toxicity To Inhaled Erbium Oxide Nanoparticles In Golden Syrian Hamsters, Randy Liang

Theses and Dissertations

Erbium oxide nanoparticles (Er2O3 NPs) are used in various products from simple pottery to semiconductors and such usage leads to an elevated risk of accidental occupational exposure. In the present study, the pulmonary toxicity of Er2O3 NPs was assessed by examining tissues and bronchoalveolar lavage fluid (BALF) from the lungs of Golden Syrian Hamsters following inhalation exposure. The study’s goal was to determine the severity and mechanism of toxicity upon exposure to inhaled Er2O3 NPs. Animals were divided into 4 groups all being exposed for 4 hours a day for 8 days: Group-1: room air, Group-2: vehicle control (water), Group-3: …

Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber

Journal of Earth and Life Science

Brown Bullhead Ameiurus nebulosus, Yellow Bullhead Ameiurus natalis, and Bluegill Lepomis macrochirus are unique in their stark differences. Bullhead are scaleless bottom feeders that can tolerate high pollution and low O₂ conditions. In contrast, Bluegill are scaled, aggressive nesters and are less tolerant of high pollutants or low-oxygen conditions. Among these pollutants include a class of chemicals called neonicotinoids (hereafter referred to as neonics). Neonics are a class of insecticides primarily used within agriculture and pest management. Due to the effectiveness, application has escalated on a global scale. They have been well documented by many toxicology assessments. …

Identifying Rna Splicing Changes During Alcohol Withdrawal Using An Optimized Rna-Seq Analysis Pipeline, Yasaswi Veera, Luana Martins De Carvalho, Amy Lasek

Undergraduate Research Posters

Alcohol use disorder (AUD) causes long-lasting changes in brain gene expression and RNA splicing, particularly in the ventral hippocampus. This study analyzes RNA-Seq data from rats exposed to chronic alcohol and withdrawal to identify transcript-level and splicing alterations. An optimized RNA-Seq pipeline using STAR, FeatureCounts, edgeR, and WGCNA improved efficiency by 25-40% while maintaining consistency across 25 datasets. Results reveal changes in neural signaling and stress-response pathways associated with withdrawal. This work provides both biological insight into AUD and a reproducible computational framework for transcriptomic analysis.

Effects Of Photo-Oxidized Crude Oil On Gulf Killifish Early Life Stages, Charles Campbell

LSU Master's Theses

Photo-oxidation of spilled crude oil generates polar compounds that can heighten toxicity to marine fish embryos. We investigated the effects of photo-oxidized crude oil on early life stages of Gulf killifish (Fundulus grandis) by exposing embryos under flow-through conditions to water-accommodated fractions of four oil treatments: fresh oil unexposed to either sunlight or weathering referred to as dark control (DC), a UV-light oxidized whole oil (LT), the polar fraction extracted from LT (Pol) and the remnants after extracting the Pol from LT (NP). Oil loadings of 0.38–3.00 g oil/kg water were tested. Total PAH concentrations and chemical profiles …

Assessing The Behavioral Impact Of Pyridostigmine Bromide In Rats, Noah A. Martin

Honors Theses

Pyridostigmine bromide (PB) is an organophosphate (OP) nerve agent prophylactic used to protect warfighters against chemical warfare agents. OPs inhibit the neural enzyme acetylcholinesterase (AChE) in the brain. This leads to the buildup of acetylcholine, causing respiratory failure, seizures, and death. PB functions by inhibiting ~30% of peripheral AChE temporarily, protecting the enzymes so that the body is able to restore sufficient cholinergic function post-exposure. PB does not cross the blood-brain barrier, though it may still indirectly affect toxicity in the brain due to repeated AChE inhibition throughout treatment, or by inhibition of non-target ChE’s in the blood. The aim …

Zonal Hepatocellular Responses To Acute Ethanol: Impacts On Mitochondrial Function And Metabolism, Matthew T. Savoca

MUSC Theses and Dissertations

Background: Ethanol (EtOH) consumption causes hepatocellular mitochondrial depolarization (mtDepo) and mitophagy. Here, the Aims were to develop techniques to characterize sublobular hepatocellular metabolism and the distribution of mtDepo and mitophagy after acute EtOH. Methods: Wildtype and GFP-LC3 transgenic mice were treated with EtOH or vehicle and administered the covalently labeling mitochondrial membrane potential (ΔΨ) reporter, MitoTracker Red (MTR), and/or the non-covalent ΔΨ reporter, rhodamine 123 (Rh123), prior to intravital imaging, liver fixation, or hepatocyte isolation. After in vivo MTR, hepatocytes were isolated and sorted. Enrichment in E-cadherin (ECAD) and cytochrome P4502E1 in periportal (PP) and pericentral (PC) hepatocytes, respectively, validated …

Potentiation Of Gelonin Cytotoxicity By Pulsed Electric Fields, Olga N. Pakhomova, Eleni Zivla, Giedre Silkuniene, Mantas Silkunas, Andrei G. Pakhomov

Bioelectrics Publications

Gelonin is a ribosome-inactivating protein with extreme intracellular toxicity but poor permeation into cells. Targeted disruption of cell membranes to facilitate gelonin entry is explored for cancer and tissue ablation. We demonstrate a hundreds- to thousands-fold enhancement of gelonin cytotoxicity by pulsed electric fields in the T24, U-87, and CT26 cell lines. The effective gelonin concentration to kill 50% of cells (EC₅₀) after electroporation ranged from <1 nM to about 100 nM. For intact cells, the EC₅₀ was unattainable even at the highest gelonin concentration of 1000 nM, which reduced cell survival by only 5–15%. For isoeffective electroporation treatments using 300 ns, 9 µs, and 100 µs pulses, longer pulses were more efficient at lowering gelonin EC₅₀. Increasing the electric field strength of 8, 100 µs pulses from 0.65 to 1.25 kV/cm reduced gelonin EC₅₀ from 128 nM to 0.72 nM. Conversely, the presence of 100 nM gelonin enabled a more than 20-fold reduction in the number of pulses required for equivalent cell killing. Pulsed electric field-mediated delivery of gelonin shows promise for hyperplasia ablation at concentrations sufficiently low to minimize or avoid systemic toxicity.

Pharmacokinetic Modeling Of Metonitazene And Isotonitazene Using In Vitro And In Vivo Models And Comparison To Human Postmortem Casework, Justine P. Sorrentino

Theses and Dissertations

Metonitazene and isotonitazene are two benzimidazole opioids that are contributing to the opioid crisis nationwide. Limited pharmacokinetic data has been published on these nitazene compounds, therefore this study sought to determine if these two structurally similar opioids would have comparable half-lives and clearance utilizing in vitro and in vivo models. Using the data determined in the pharmacokinetic study, and by testing human postmortem cases, this study aimed to inform interpretation of these drugs detected in human casework. Sample analysis for all aspects of the study was performed utilizing LC/MS/MS. In vitro pharmacokinetics of both drugs were examined using a human …

The Method Development And Validation Of Designer Benzodiazepines In Oral Fluid Using Solid Phase Extraction And Lc-Ms/Ms, Jenna L. Monsell

Student Theses

Oral fluid is a useful biological matrix. Collection is non-invasive, quick, observable, and its correlation between oral fluid and blood drug concentration make oral fluid an important matrix to use as a roadside test. Designer benzodiazepines have become increasingly popular over the years, adversely affecting motor skills and leading to driving under the influence. Many previous studies have focused on the method development and validation of designer benzodiazepines in blood and hair but fail to validate a method to detect designer benzodiazepines in oral fluid. This study focuses on the method validation of 13 designer benzodiazepines in oral fluid using …

Hair And Drugs: The Impact Of Dry Shampoo And Gel On Cocaine-Contaminated Hair, Marialejandra Faure Betancourt

Student Theses

Hair is a biological sample used in forensic toxicology to identify and quantify drug exposure. However, when interpreting analytical results, hair can be challenging due to the presence of external contamination. Previous studies have shown that cosmetic treatments remove drugs within the hair shaft decreasing their concentration. Nevertheless, not enough information is available to explain this phenomenon. This study focused to determine whether cosmetic products such as dry shampoo and gel influence the concentration of externally deposited cocaine (COC) and benzoylecgonine (BE) in different hair types/colors. Hair samples from fifteen COC-free volunteers of various hair colors/types were collected and divided …

Investigating Stormwater Parameters From Runoff On East Tennessee State University Campus, Abby Mciver, Dr. Joseph R. Bidwell

Undergraduate Honors Theses

Climate change has caused an increase in extreme rain events and flooding in certain regions across the globe. During rain events, water flows over impervious surfaces structures such as roads and sidewalks, picking up contaminants such as metals, fertilizers and other nutrients, and various organics that which may impact organisms in such as streams, river, and lakes. Previous work has found significant differences in survival of organisms that were exposed to contaminated stormwater runoff. This study investigated stormwater chemistry parameters at collection sites on the East Tennessee State University campus. Sites were selected based on the extent of human interaction …

Examining The Oxidative Stress Effects In Rats Exposed To 2-Aminoanthracene In Utero And High Fat Diet Three Months After, Brianna A. Lanoix

Honors College Theses

Polycyclic aromatic hydrocarbons are organic compounds that are created synthetically or found in partially burned oil, gasoline, and coal. 2-aminoanthracene (2AA) is a common example of a PAH and can affect lipid and carbohydrate metabolism and resulting in inflammatory problems and oxidative stress. The objective of the research project is to investigate oxidative stress in relation to diabetes in rats exposed to 2AA in utero and a high fat diet later in life. Pregnant dams were separated into treatment groups based on their dosages of 2AA; 0 mg/kg (control), 50 mg/kg (low), 100 mg/kg (high). During the gestation -postpartum period, …

The Intersection Between Toxicology And Aging Research: A Toxic Aging Coin Perspective., John P. Wise Jr.

Faculty and Staff Scholarship

We are imminently faced with the challenges of an increasingly aging population and longer lifespans due to improved health care. Concomitantly, we are faced with ubiquitous environmental pollution linked with various health effects and age-related diseases which contribute to increased morbidity with age. Geriatric populations are rarely considered in the development of environmental regulations or in toxicology research. Today, life expectancy is often into one’s 80s or beyond, which means multiple decades living as a geriatric individual. Hence, adverse health effects and late-onset diseases might be due to environmental exposures as a geriatric, and we currently have no way of …

Elisa Validation Method For The Detection Of Ketamine In Hair, Daria A. Centonza

Student Theses

An ELISA method was developed and validated to detect ketamine in human hair samples. Ketamine is an anesthetic drug that causes memory loss, dissociative sensations, and hallucinations. Due to these adverse effects, ketamine is a common drug used in drug facilitated sexual assaults (DFSAs). It is very important to be able to detect the substances used in DFSAs over a longer period of time due to the delayed reporting of these crimes. Victims, often out of fear and from the sedative/memory loss effects of the drugs, tend to report these crimes when it is too late to use urine and …

The Sublethal Response Of Cambarus Sp. To Acute Low Dose Herbicide Exposure Evidenced By A Change In Ggt Levels And Apoptosis, Amelia Wickham

Senior Honors Theses

Following application, herbicidal runoff can collect in freshwater ecosystems, briefly exposing non-target organisms. As biological indicators, crayfish serve as models to assess freshwater health. Chemically stressed crayfish form reactive oxygen species (ROS) which are neutralized by the glutathione pathway. As glutathione depletes, γ-glutamyl-transferase (GGT) upregulates to increase glutathione formation. High oxidative stress lowers glutathione levels and subsequent apoptosis occurs. For this acute study, crayfish were exposed to 5ppb and 50ppb of atrazine, glyphosate, and 2,4-D. Herbicide exposures were expected to induce higher GGT production, increased oxidative stress, and increased apoptosis. Instead, GGT and apoptosis predominately decreased relative to the control. …

Effect Of Metal-Containing Nanoparticles On Bacterial Biofilms And On The Microbiome Of Girardia Tigrina, Azar Saikali

West Chester University Master’s Theses

Anthropogenically-produced nanoparticles are a form of nanotechnology being used in industries including food and textiles. Humans and livestock are frequently exposed to metal-containing nanoparticles (MCNPs), that have been washed into streams and rivers, have been deliberately used in food packaging as antimicrobials, preservatives or for supplementation. The animal microbiome, which consists of a diverse community of microorganisms, provides a number of benefits to the host in terms of nutrition availability, immune support, and can influence behavior. Biofilms of diverse microbes may cause detrimental effects, for instance by causing dental diseases in humans. However, the scientific community has not reached consensus …

Avian Haemosporidian Blood Parasite Diversity, Prevalence, And Distribution In Michigan’S Western Upper Peninsula, Maria M. Ferrer

Dissertations, Master's Theses and Master's Reports

Avian haemosporidian parasites, known as avian malaria (phylum Apicomplexa) can diminish an individual bird’s fitness by causing parasitemia, anemia, and reduced survival. Climate change is predicted to increase the spread of malarial parasites into more northerly latitudes where little is known about community compositions of these parasites. I assessed the prevalence and diversity of haemosporidian parasites in the first-ever community-level sampling of malaria in songbirds across the western Upper Peninsula of Michigan. In total, 179 blood samples were collected from birds representing 17 species, at five locations in the Upper Peninsula, including a mature forest, an early successional forest, and …

Toxicology Of Chemical Stress To Monarch Butterflies (Danaus Plexippus L.), Annie Krueger

Department of Entomology: Dissertations, Theses, and Student Research

Monarch butterfly (Danaus plexippus L.) population declines have caught the attention of the country and prompted nationwide conservation initiatives. The United States Fish and Wildlife Service has identified insecticide exposure and loss of milkweed (Asclepias spp.) reproductive habitat as primary threats to the monarch. In the Midwestern US, milkweed largely occurs around cropland borders where there may be a spatial and temporal overlap of monarch larvae, insecticide usage, and fertilizer applications. In this study, the acute toxicity and sub-lethal effects on growth and diet consumption of two commonly used pyrethroid insecticides, bifenthrin and beta-cyfluthrin, were characterized …

Addressing Uncertainties Of Polychlorinated Biphenyls In Schools, Alice Fan

Master's Projects and Capstones

Despite the potential neurological health deficits resulting from polychlorinated biphenyls, there is a lack of inhalation studies and regulations to protect students and teachers who are widely exposed to PCBs in older (1950 to 1979) schools. To estimate the extent of PCB detections in Los Angeles County schools, I applied a mathematical model to estimate the range of PCB detections in schools built between 1950 and 1984. I estimate the range of 17-34% PCB detections of open schools within Los Angeles County. Next, I reviewed exposure tools provided by the US EPA to bridge the uncertainty gaps between ingestion and …

David S. Miller: Scientist, Mentor, Friend--A Tribute And Thank You, Björn Bauer, J. Larry Renfro, Karl J. Karnaky, Rosalinde Masereeuw, Gert Fricker, Ron E. Cannon, Anika M. S. Hartz

Pharmaceutical Sciences Faculty Publications

David S. Miller was Acting Scientific Director of the Division of Intramural Research at the National Institute of Environmental Health Sciences, National Institutes of Health, and Head of the Intracellular Regulation Group in the Laboratory of Toxicology and Pharmacology before he retired in 2016. David received his Ph.D. in biochemistry from the University of Maine in 1973. David was a Group Leader at the Michigan Cancer Foundation before joining the NIEHS in 1985. His research covered a wide range from renal excretory transport mechanisms to regulation of transporters at the blood-CSF and blood-brain barriers, from fish, amphibians and birds to …

A Health Evaluation Of Gulf Of Mexico Golden Tilefish (Lopholatilus Chamaeleonticeps) And Red Snapper (Lutjanus Campechanus) Following The Deepwater Horizon Oil Spill, Kristina Leigh Deak

USF Tampa Graduate Theses and Dissertations

A lack of baseline heath indices for offshore Gulf of Mexico (GoM) teleosts complicated impact assessments of the Deepwater Horizon (DWH) oil spill. While measurement of contaminant levels in fish after a pollution event can document exposure, such data fail to provide meaningful information about how this contact affects an animal's physiology. Controlled exposure studies have highlighted the utility of biomarkers that may indicate deleterious, long-lasting effects of pollutant exposure on various life stages of fish, however, their extrapolation to wild-caught, non-model species is challenging. In an increasingly chemically-saturated environment, it can also be difficult to separate the influence of …

Investigating The Toxicology Of Intramuscular Injected Cnt-Ab In Mice Followed By Microwave Hyperthermia., Conner Clark

Honors College Theses

The advent of carbon nanotubes (CNTs) has led to a wide range of research in various fields including cancer therapy for targeting specific localized and site-specific treatment. Carbon nanotubes bound to tumor specific antibodies (Ab) offers specific treatment for cancer cells without affecting surrounding tissue. This treatment makes use of infrared absorptive properties of nanotubes to incinerate both the nanotube and its associated tumor in vivo. We seek to affirm the initial results of CNT in cancer therapy by investigating the toxicological effect in mice injected with CNT-Ab followed by microwave hypothermia. After 1-week post-injection, mice were sacrificed followed …

Assessing Field-Scale Risks Of Foliar Insecticide Applications To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Yang Zhang, Keith G. Bidne, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Establishment and maintenance of milkweed plants (Asclepias spp.) in agricultural landscapes of the north central United States are needed to reverse the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Because of a lack of toxicity data, it is unclear how insecticide use may reduce monarch productivity when milkweed habitat is placed near maize and soybean fields. To assess the potential effects of foliar insecticides, acute cuticular and dietary toxicity of 5 representative active ingredients were determined: beta-cyfluthrin (pyrethroid), chlorantraniliprole (anthranilic diamide), chlorpyrifos (organophosphate), and imidacloprid and thiamethoxam (neonicotinoids). Cuticular median lethal dose values for …

Exosomes As Systemic Mediators Of Nanotube Induced Neurotoxicity, Christopher G. Canal

Theses and Dissertations

Extra-pulmonary effects of nanoparticle inhalation have been well documented; however, mechanisms for conveying peripheral bioactivity remain elusive. Recent studies point to indirect molecular mediators shed into the circulation. Protein and lipid alternatives to cytokines or chemokines have been proposed, yet the diversity among responses suggests a broader assemblage of factors. Recently we have proposed proteolytic fragment peptides as an additional source of bioactivity, which interestingly were significantly associated with exosomal proteins after enrichment analysis. Here we tested whether modeled exposure to multi-walled carbon nanotubes (MWCNT) could alter the composition and bioactivity of circulating exosomes. Male C57BL/6 mice were exposed by …

The Combined Effects Of Chemicals Used In Textile Processing On Plankton Communities., Diana Wilson

Honors College Theses

Industrial discharge, such as textile effluent, is a major source of chemical mixtures to surface waters. The effects of these mixtures on interacting aquatic organisms can be difficult to predict. We hypothesized that individual chemical effects on phytoplankton and a zooplankton grazer are altered by the presence of other chemicals in mixtures. Microcosms containing a phytoplankton food source (Chlorella sp.) and a zooplankton grazer (Daphnia magna) were exposed to THPC, ammonium, and hydrogen peroxide in a fully crossed design in a greenhouse for one week. Phytoplankton abundance was quantified and zooplankton response was measured as mortality and …

A Mechanistic Study Of The Teratogenic Potential Of 4-O-Methylhonokiol (Mh) On Japanese Medaka (Oryzias Latipes), Santu Kumar Singha

Electronic Theses and Dissertations

An additional goal of this project was to characterize the Wnt/β-catenin signaling pathway to unravel the adverse potential of MH on the cardiovascular system (CVS). Our study suggested that MH-mediated cardiovascular injury may be caused due to upregulation of some major components of the Wnt/β-catenin pathway through expression of excessive pro-inflammatory mediators. Moreover MH decreased expression of ErbB3 and NRG-2 suggesting impaired cardiac structure. MH exposure caused a slow heartbeat blood occlusion absence of blood circulation decreased hatching efficiency and increased mortality in medaka embryos in a concentration- and time-dependent manner. MH might cause blood vessel occlusion by increasing the …

Zolpidem Facilitated Sexual Assaults: A Hair Method Validation, Danielle N. Chasworth

Student Theses

A liquid chromatography tandem mass spectrometry (LC-MSMS) method was developed and validated to detect for the presence of zolpidem in human hair samples. Zolpidem is a sedative hypnotic whose adverse effects make it a common drug found in drug facilitated crimes (DFC). It is important to be able to detect and quantitate the drug after a long period of time due to the victim’s delayed reporting of the crime. Hair’s long window of detection makes it a useful matrix for DFC investigations. The linear range of the assay was targeted at 2 pg/mg to 1,000 pg/mg and experiments designed to …

The Combined Effects Of Atrazine And Tetracycline On Primary Producers And Zooplankton In Freshwater Microcosms, Madison R. Kelly

Honors College Theses

Widespread use of agrochemicals such as herbicides and antibiotics increases their likelihood of entering aquatic systems in mixture. Despite different modes of action, atrazine (herbicide) and tetracycline (antibiotic) adversely affect non-target photosynthetic organisms, such algae and macrophytes, with the potential to reduce food availability to higher trophic levels. However, the effects of simultaneous exposure to both contaminants have yet to be determined. I hypothesized that a mixture of atrazine and tetracycline affects freshwater communities differently than each compound alone. A microcosm experiment was conducted to test effects of environmentally relevant concentrations of atrazine (1 μg L^-1) and tetracycline …