Toxicology Commons^™

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Menthalactone From Mentha Piperita L., A Monocot-Selective Bioherbicide, Adam Soltani

Honors Theses

The challenge of managing invasive weed species continues to affect the agricultural industry, presenting ecological, economic, and agronomic hurdles that lead to over 100 billion USD in annual crop losses globally. One such concern is the management of Agrostis stolonifera L., commonly known as creeping bentgrass, particularly due to its ability to form hybrids. This scenario underscores the urgent need for innovative, effective, and environmentally sustainable herbicides, steering the focus toward natural substances as potential candidates. We report here a promising natural lactone, commonly known as menthalactone, which is derived from Mentha piperita L. Its phytotoxic activity was assessed against …

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 …

Early Developmental Exposure To Δ9-Tetrahydrocannabinol Causes Latent Behavioral, Growth, And Bioenergetic Effects In Danio Rerio, Astra Hahm

Honors Theses

Early developmental exposure to Δ9-tetrahydrocannabinol causes latent behavioral, growth, and bioenergetic effects in Danio rerio

(Under the direction of Dr. Kristine Willett)

Δ9-tetrahydrocannabinol (Δ9-THC) is used during pregnancy to mitigate symptoms such as nausea, pain, and insomnia. It is established that Δ9-THC exposure early in life causes adverse effects in children’s development including behavioral disorders. Our goal was to determine the latent and generational impacts on growth, behavior, and mitochondrial bioenergetics following exposure to Δ9-THC. Wildtype (5D) zebrafish were exposed to 0 (0.05% DMSO), 0.08, 0.4, or 1 µM Δ9-THC from 6-96 hours post-fertilization (hpf), then subsequently raised in clean …

Validation Of A Triple Quadrupole Lcms Instrument For Cocaine And Amphetamines, Isabel R. Nichols

Honors Theses

Despite the opioid crisis taking headlines, the abuse of cocaine and amphetamines remains rampant and laboratory instruments must be able to effectively and reliably handle the overwhelming case load. In this study, an Agilent 6475 Triple Quadrupole (QQQ) LCMS, recently acquired by the Tarrant County Medical Examiner’s Office (TCMEO) in Fort Worth, Texas, was validated for identifying and quantifying CocAmps. Results show that the instrument was fit-for-purpose and that the instrument passed all validation tests. Reproducibility was ≤ 20% RSD for 12 QC replicates, 6 of blood and 6 of urine. Accuracy was ± 20%. A 98.9% recovery was yielded …

Trends In Cyanotoxin Production Potential In China Lake: An Edna Analysis Of Microcystis And Dolichospermum And The Environmental Drivers Of Cyanotoxin Production, Gennifer M. Rubin

Honors Theses

Episodes of cyano-harmful algal blooms (cyano-HABs) are hypothesized to be exacerbated by the effects of climate change. However, the dynamics of the interactions between elements of climate change and toxigenic cyanobacteria proliferation are not well defined. China Lake is the drinking water source for 7 municipalities in the Kennebec County and is one of many lakes in central Maine that has been subjected to high levels of cyano-HABs and microcystin toxin contamination in recent years. Monitoring the toxicity of these blooms in relation to various aspects of climate change may lead to identification of the major drivers of microcystin production …

Black Carbon And Meteorological Parameters At Two Locations In Northern Mississippi, Ashton Swader

Honors Theses

Black Carbon, which is a component of fine particulate matter, is a known pollutant that has been linked to the development of several diseases including cardiovascular disease. This pollutant can be measured by taking samples of air within a certain region and analyzing them using a transmissometer. It is known that black carbon concentrations tend to be higher in urban areas when compared to rural areas within a region. Black carbon concentrations can also vary depending on certain meteorological parameters such as temperature and humidity. There were no current studies that analyze the air quality in northern Mississippi due to …

Pfas Environmental Contamination In Central Maine, Megan H. Andersen

Honors Theses

PFAS (per- and polyfluoroalkyl substances) are toxic, persistent, and bioaccumulative chemicals that are used in a variety of consumer products and industrial applications. Paper mills across the state of Maine have used PFAS in their industrial paper making processes, and their wastes often flow for treatment into municipal sewage treatment facilities. PFAS contaminated municipal wastewater from the general use of PFAS consumer products are also processed by these plants. Liquid waste is condensed into solid waste septage and sludge, and in what was thought to be an environmentally friendly repurposing practice, municipal sludge and septage has been spread on plots …

Determination Of Metals And Microplastics In Sediment From Oyster Reefs In The Mississippi Sound, Shelby Goza

Honors Theses

This research centers on the determination of metals (Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu) and microplastics (MPs) in marine sediment from oyster reefs in the Mississippi Sound Estuary. Oysters (Crassostrea virginica) are a vital part of the Gulf Coast economy, but their population has dramatically declined in recent years due to multiple stressors, including oil spills and fluctuations in salinity from flooding. Increasingly frequent flooding events also introduce high loads of MPs and sediments containing heavy metals from the Mississippi River. These pollutants can have deleterious effects on oyster biology; however, they have not been adequately …

Composition And Oxidative Potential Of Fine Particulate Matter From Pascagoula, Ms, Madison Smith

Honors Theses

Air pollution is one of the top-ranking risk factors for death and disability around the world, accounting for nearly 4.9 million deaths worldwide (State of Global Air, 2019). Specifically, fine particulate matter (PM_2.5) has been linked to many adverse effects on human health, yet there is very little known about what characteristics exactly cause these adverse health effects and how they cause them. Samples for this study were collected from Pascagoula, MS, a small town located on the Mississippi Gulf Coast that is home to many industrial yards, from September 2013 to December 2013. Black carbon (BC) analysis …

Responses To Fine Particulate Matter (Pm2.5) Exposures In Two Wild-Type Zebrafish Strains, Connor Necaise

Honors Theses

Atmospheric fine particulate matter (PM_2.5) exposure poses great health risks across the globe, causing both acute and chronic illnesses in humans. Therefore, a more complete understanding of the mechanisms in which PM_2.5 induces these adverse health effects is urgently needed. Oxidative stress due to PAHs and other common components of PM_2.5 is a proposed mechanism for its adverse health effects. However, little is known about the actual mechanisms of PM_2.5 damage in humans. This study aimed to distinguish behavioral differences in two lines of zebrafish (AB & 5D) as a result of developmental exposure to …

Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma, Shahbaz Gul

Honors Theses

Depression has become one of the most prominent problems in society, disrupting both personal and social lives. Tricyclic antidepressants (TCAs) were first developed in the 1950’s and became some of the leading anti-depressant medications on the market later that decade. Today, newer anti-depressants have risen to the forefront, being safer and having a lower side-effect probability. Nonetheless, TCAs continue to be prescribed for severe depression, especially in cases where the newer anti-depressants have failed. However, TCAs are still highly potent, the toxicity associated with these compounds cannot be ignored. They have considerable cardiovascular and neurological toxicity, and in the event …

Oxidative Potential And Composition Of Fine Particulate Matter At Two Locations In Mississippi, Victoria Claire Stevens

Honors Theses

Air pollution exposure has negative health effects on individuals across the globe. Negative impacts on human health have been documented in studies following both short-term and long-term exposure to air pollution, and these adverse effects have been seen even at the lowest levels of exposure. Fine particulate matter (PM_2.5) has specifically been linked to these negative health effects. These effects come from many sources, but one large contribution to the negative health effects comes from oxidative stress. In this study, samples were collected from Hernando, MS and Gulfport, MS in September 2013 and November 2013. Black carbon (BC) …

Lead, Copper, And Iron In University Tap Water, Alison Mclendon

Honors Theses

This study observed concentrations of lead, copper, and iron in university tap water over an eight-week span during and between the summer and fall semesters. First draw and 30s flush samples were taken after overnight stagnation from the Honor House, College Hall, J. B. George Building, and International Center bathrooms and analyzed with an inductively-coupled plasma mass spectrometer (ICPMS). There was no obvious correlation between time in the semester and metal concentrations. Relative iron levels rose and fell at the same time in all buildings, but there was little correlation between buildings for lead and copper concentrations. The Honor House …

A Broad-Spectrum Mer Operon In A Multi-Drug Resistant Strain Of The Fish Pathogen, Aeromonas Salmonicida, Erin Parry

Honors Theses

Aeromonas salmonicida AS03, a potential fish pathogen, was isolated from Atlantic salmon, Salmo salar, in 2003. This strain was found to be resistant to ≥1000 mM HgCl2 and ≥32 mM phenylmercuric acetate as well as multiple antimicrobials. Mercury (Hg) and antibiotic resistance genes are often located on the same mobile genetic elements, so the genetic determinants of both resistances and the possibility of horizontal gene transfer were examined. Specific PCR primers were used to amplify and sequence distinctive regions of the mer operon. A. salmonicida AS03 was found to have a pDU1358-like broad-spectrum mer operon, containing merB as well as …

Cytogenetic Test Of Captan And Triethylenemelamine In Mouse Bone Marrow, Stephen M. Fry

Honors Theses

Following a single non-toxic i.p. injection with 0.5 or 1.0 mg triethylenemelamine/kig a significant increase in chromosome aberrations in mouse bone marrow was observed 6, 12, 30, but not 54 h after treatment. A single i.p. injection with 250 mg captan/kig caused up to 68% lethality above controls, but no significant increase in chromosome aberrations after the same time intervals. One metacentric chromosome was observed 6, 30, and 54 h after captan treatment among 300, 300, and 101 metaphase spreads respectively, whereas none appeared in 1495 control spreads.

The Great Potato Debate, James D. Hudson

Honors Theses

Anencephaly and spina bifida cystica are two of the most common severe congenital malformations consistently observed in human populations. Both represent defects in the neural tube and share a significant number of similar epidemiological associations among them, occupational class, geography, sex ratio, maternal age, year and season of the year. In anencephaly most of the brain and upper skull never form usually resulting in death within a few hours of birth. Spina bifida cystica is a malformation of the spinal cord often causing paralysis, vulnerability to infection, and early death. In 1972, Dr. J.H. Renwick presented a controversial hypothesis which …