Toxicology Commons^™

Toxicity Of The Technology Critical Elements Germanium And Yttrium To Daphnia Magna And Hyalella Azteca And The Influence Of Toxicity Modifying Factors, Rashid Shah

Theses and Dissertations (Comprehensive)

Technology critical elements (TCEs) are increasingly used in high and green technologies but there is little aquatic toxicity data for TCEs, particularly in fresh water. The objective of this study was to investigate the toxicity of two TCEs, Ge and Y, to Daphnia magna and Hyalella azteca and to understand the role of natural organic matter and cations on toxicity modification. Testing followed standard methods. The 48 h EC50 for D. magna was 11.6 (95% CI of 9.64-13.8) mg Ge/L based on measured dissolved concentrations at test end. The addition of NOM at 10 mg DOC/L resulted in a significant …

Prunus Africanus Herbal Extracts Reverse And Ameliorate The Histological And Histomorphometric Changes In Testosterone-Induced Benign Prostate Hyperplasia Rat Models, Felix P. William, Denis A. Russa

Tanzania Journal of Science

Benign prostatic hyperplasia (BPH) is the most common benign proliferative disease among men during aging. The herbal extract of P. africanus has been used for the treatment of BPH since time immemorial. However microstructural changes of this extract to the prostate of animal or human models are still elusive. Therefore, histological and histomorphometric changes in rats with testosterone-induced BPH due to P. africanus herbal extracts were investigated. Twenty-eight male Wistar rats (200 ± 50 g) were divided into four groups each with 7 rats. Group 1 (Negative control) was given 2 ml/day of olive oil subcutaneously and 2 ml/day of …

Neonicotinoids Can Cause Arrested Pupal Ecdysis In Lepidoptera, Niranjana Krishnan, Russell A. Jurenka, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Recently, we reported a novel mode of action in monarch butterfly (Danaus plexippus) larvae exposed to neonicotinoid insecticides: arrest in pupal ecdysis following successful larval ecdysis. In this paper, we explore arrested pupal ecdysis in greater detail and propose adverse outcome pathways to explain how neonicotinoids cause this effect. Using imidacloprid as a model compound, we determined that final-instar monarchs, corn earworms (Helicoverpa zea), and wax moths (Galleria mellonella) showed high susceptibility to arrested pupal ecdysis while painted ladies (Vanessa cardui) and red admirals (Vanessa atalanta) showed low susceptibility. Fall …

Manipulation Of The Microbiome In The Gut Of The Fruit Fly To Alleviate Cadmium Bioaccumulation, Natasya Tamba

Symposium of Student Scholars

Cadmium (Cd) poisoning contributes to severe bodily detriments characterized by kidney failure, osteomalacia, and osteoporosis, otherwise known as Itai-Itai disease. The ingestion of cadmium contaminated foods primarily causes these conditions. There are no treatments to remove cadmium once absorbed, resulting in bioaccumulation. In this study, we are developing a method to manipulate the community of microorganisms (microbiome) living within the gastrointestinal (GI) tract of the fruit fly (Drosophila melanogaster), intending to use microorganisms to reduce the availability of ingested cadmium.

The biodiversity of microorganisms within the GI tract is responsible for metabolizing substances that the body cannot perform. …

Effects Of Heavy Metal Pollution On The Antipredator Behavior Of Orangethroat Darters (Etheostoma Spectabile), Caleb S. O'Neal

Graduate Theses/Dissertations

Heavy metal pollution can have numerous negative impacts on stream fishes, including both lethal and sublethal effects. Because of the sensitivity of fishes to toxins, they are excellent environmental indicators of stream and watershed health. The Tri-State Mining District is a Superfund site located in parts of Missouri, Kansas and Oklahoma that offers a good opportunity to study sublethal effects of heavy metal pollutants on fish behavior. I observed the antipredator behavior of Orangethroat Darters (Etheostoma spectabile) from 3 streams that varied in the abundance of heavy metal pollutants. In the lab, darters from the most polluted site …

Pectin And Alginate Extraction To Treat Liquid Cafo Manure, Clare Sunderman

Honors Projects

For this project, various extraction methods were used to extract pectin from Pastinaca Sativa and alginate from Macrocystis. These extractions were then dried and used in treating 250mL of manure along with a CaCl₂ or FeCl₃ coagulant. It was found that CaCl₂ was not as effective as FeCl₃ in coagulating manure. But the results obtained suggest that pectin and alginate obtained with a simpler extraction method is just as effective as the highly purified and refined pectin and alginate produced for the food industry, in the treatment of CAFO manure. The liquid portion of the …

Comparative Effects Of Chemical And Physical Sunscreen On Fertilization Of Purple Sea Urchins (Strongylocentrotus Purpuratus), Marilla Lippert, Maurice Codespoti Goodman, Nikki Adams

Biological Sciences

Organic compound-based “chemical” sunscreens dominate the commercial sunscreen market, but recent research has revealed the ingredients of these products are detrimental to the health of marine organisms. This revelation has led to increased popularity of mineral-based “physical” sunscreens, primarily containing zinc-oxide (ZnO), as environmentally safe alternatives. While they are marketed as environmentally safe, these claims are largely untested, and it is important to consider potential effects of ZnO-based sunscreens on the development of marine organisms. Though Zn is a necessary micronutrient in the ocean, excess Zn is released into marine environments from anthropogenic sources has negative effects on marine life. …

Mechanisms Of Cadmium-Induced And Epidermal Growth Factor Receptor Mutation-Driven Lung Tumorigenesis, Hsuan-Pei Lin

Theses and Dissertations--Toxicology and Cancer Biology

Cadmium (Cd) is a ubiquitous pollutant in the environment and a known carcinogen for lung cancer. Cd has been shown to act as a weak mutagen, which suggests that it may exert tumorigenic effect through non-genotoxic ways, such as epigenetic mechanisms. The goal of this project is to investigate the mechanisms of Cd carcinogenesis focusing on the role of lncRNA dysregulations. The Cd-exposed cells formed significantly more colonies in soft agar, displayed cancer stem cell (CSC)-like property and formed tumors in nude mice. Mechanistically, the lncRNA microarray analysis revealed that chronic Cd exposure dysregulates lncRNA expressions. Q-PCR analysis confirmed the …

The Effects Of Fluoride On Macrophage Thp-1 Cell Apoptosis, Jessica Heims

Honors Program Theses

Fluoride is an earthly mineral that occurs naturally both in the sedimentary earth as well as in the human body. The main biological function of fluoride in the human body is to enhance bone structure, as well as prevent the decay of teeth. This mineral has been used by dentists and public health officials to artificially introduce an extra layer of protection through the means of fluoride-enriched public water supplies and toothpastes. By using extra levels of fluoride, dentists have been able to help patients prevent future cavities and dental diseases. Although most dentists highly encourage strategic consumption of these …

Investigating Dose-Dependent, Multi-Generational, And Strain-Specific Effects Of 17Α-Ethynylestradiol Exposure In Zebrafish (Danio Rerio), Decatur Mitochondria Foster

Dissertations and Theses

Endocrine disrupting chemicals (EDCs) pose a threat to biodiversity at the individual, population, and ecosystem level, as they can interfere with processes that are responsible for regulating metabolism, development, behavior, and reproduction in living organisms. 17α-ethynylestradiol (EE2) is a synthetic estrogen and EDC utilized in pharmaceutical and livestock industries, and contaminates waterways worldwide. This research explores the effects of dose-dependent and multi-generational exposure of EE2 in three strains of zebrafish. High dose (10-25 ng/L EE2) exposure led to complete reproductive failure, as well as significantly decreased survival and growth. A period in clean water (depuration) after exposure allowed for some …

Hepatobiliary Polycyclic Aromatic Hydrocarbons In Pelagic Fishes Of The Gulf Of Mexico, Madison R. Schwaab

USF Tampa Graduate Theses and Dissertations

Fisheries populations and their ecosystems are negatively impacted by both chronic and acute inputs of pollutants, including oil spills such as the Deepwater Horizon platform blowout in 2010 in the Gulf of Mexico (GoM). After Deepwater Horizon, toxicological studies of demersal fishes of the northern GoM were undertaken to characterize impacts and to establish baseline contaminant levels in the aftermath of the spill. In this study, I quantify polycyclic aromatic hydrocarbon (PAH) concentrations in eight pelagic fish species to demonstrate oil exposure differences between species, region and time. Analysis of biliary PAH metabolite equivalents using high performance liquid chromatography was …

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 …

Assessment Of The Toxicological Effects Of Cnt-Ab In Mice Followed By Microwave Hyperthermia 14 Days Post Treatment., Andrew C. Mixson

Honors College Theses

Serious side effects and treatment resistance are the main impediments to successful cancer therapy. A variety of nanoparticles have been used for localized, site-specific treatment that prevent or circumvent these impediments. Microwaves alone have been previously used for thermal ablation of various tumors, setting precedence for their successful use in live organisms. In cell culture studies, it has been observed that multiwall carbon nanotubes (MWCNTs) instantly and efficiently absorb microwaves, causing hyperthermia of cells in direct contact with them with unnoticed harm to other cells. It is hypothesized that a treatment can be developed based on a safe microwave heating …

The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek

UCARE: Research Products

Cigarette butts are the most littered item in the world and contain over 4,000 chemicals, including the organic compound nicotine (Slaughter et al. 2011). Billions of cigarette butts are littered each year which may wash into bodies of water, impacting the local wildlife. To determine how introduced chemicals impact the environment, it is important to study its effects on indicator species. Amphibians, such as Lithobates catebeianus, act as indicator species due to their extreme sensitivity to chemical changes in its environment. The purpose of this research project was to obtain data to help determine the impact nicotine accumulation has …

The Effects Of Trichloroethylene On The Germination And Early Development Of Radish, Butternut Squash, Corn, And Soybean, Sarah Jaksich

UNO Student Research and Creative Activity Fair

Trichloroethylene (TCE) is a small molecule used as a metal degreaser and as an extraction solvent for lipids. Historically, TCE has been used to clean missiles and rockets after testing at military sites. However, TCE has decreased in use due to its potential health hazards. TCE is particularly dangerous because it is soluble in water and easily seeps into ground water. As a result, TCE has contaminated groundwater in Mead, Nebraska. The town is near the formal Nebraska Ordnance Plant, a military factory specializing in bomb assembly, ammonium nitrate production, and explosives burning. Soil sampling in Mead indicated TCE levels …

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 …

The Effect Of Seasonality On Yellow Perch Ecology And Ecotoxicology Within Lake Manganese, Bailey Duxbury

Dissertations, Master's Theses and Master's Reports

Seasonality is a consistent component of aquatic ecosystems yet most fish biological and ecotoxicological studies commonly employ field sampling protocols focused during the warm open water season with minimal emphasis placed on winter sampling, especially for north-temperate latitude ecosystems. Such strategies limit our understanding of poikilotherm biology and ecology during the overwintering seasons. Here, I investigated seasonal changes in yellow perch (Perca flavescens) biology, ecology and ecotoxicology over a one-year period in Lake Manganese. Significant seasonality was observed for metrics including fish energy densities (kJ/g), gonadosomatic indices, whole-body lipid contents, and carbon stable isotope values (δ¹³C). …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

Petri Nets As A Unifying Tool To Link Physiologically Based Toxicokinetic (Pbtk) Models To Adverse Outcome Pathways (Aops), Ian Edhlund

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Herbicide Toxicity To Non-Target Aquatic Organisms Does Not Increase In Mixtures With Surfactants, Courtney L. Telfort

Honors College Theses

Agricultural herbicides enter aquatic environments after rain events where they affect microscopic aquatic plants (phytoplankton) and animals (zooplankton) that form the base of aquatic food webs. Atrazine, an herbicide with low solubility in water, is often mixed with surfactants such as alkyl polyglucoside (APG) to improve effectiveness. Although APG has low-toxicity, a potential drawback to increased atrazine solubility is greater adverse effects on aquatic organisms. I hypothesized that atrazine and APG decrease phytoplankton abundance more than atrazine alone. Specifically, I predicted phytoplankton abundance should 1) decrease with increasing concentrations of the mixture compared to the same atrazine concentrations individually, and …

Ultrafine Black Carbon: A Cumulative Assessment On The Physiology Of Lung - Derived Cells, M Esther Salinas

Open Access Theses & Dissertations

Combustion-derived nanomaterials are noxious ultrafine (<100 nm) aerosolized by-products generated by human activity. They pose threats to pulmonary health due to their small size, allowing them to penetrate deep into the alveolar regions causing detrimental responses downstream. Indeed, an examination between nanocarbon particle exposure and poor pulmonary health via cellular behavior was needed. I hypothesized that low-dose and long-term administrations of carbonaceous nanoparticles contribute to respiratory conditions by irritating lung-derived cells. Responses to ultrafine black carbon (UBC), a key component of airborne pollutants, by human lung A549 and murine lung LA4 epithelial cells, human peripheral-blood monocytes THP1, and murine macrophages RAW264.7 were investigated. These lines were chosen because epithelial cells and mononuclear cells (monocytes and macrophages) are the first to come in contact with inhaled particulate matter (PM) and contribute to stress and inflammation of pulmonary tissues. The cells were first plated on day zero and fed fresh UBC suspended in culture media on days one, four, and seven. The exposure regimen included three different low-level concentrations of UBC. On day ten, all cells were prepared for subsequent assays. Effects on cellular viability revealed that UBC was modestly cytotoxic while ATPase and esterase activity (termed enzyme vitality for the purpose of this study) were significantly diminished in a dose-dependent manner. Additionally, beta-galactosidase proportionally increased with UBC concentration compared to untreated cells, indicating that cellular senescence was promoted across all cell types. Multiple markers of oxidative stress were subsequently measured, showing non-uniform trends and displaying moderate accumulation of oxidative damage, contingent upon cell line and UBC treatment. However, a significant induction of inner mitochondrial membrane depolarization of human UBC-treated cells was observed; an aberrant cell-cycle progression was found across all cells. The implemented regimen of UBC exposure elicited an imbalance of free (reduced) glutathione, altered mitochondrial potential, and abnormal cell-cycle activity. This method demonstrated that modifications across both species induced changes to cellular fitness overall. The data supported that compounding nanosized black carbon exposure could negatively affect overall pulmonary cell health by distinctively modifying intracellular activity. Additionally, we further surmised that sustained exposure to nanocarbon could impair innate immunity. Therefore, reactive oxygen species (ROS), reactive nitrogen species (RNS), and cytokine levels upon continuous administrations to 3.0 μg/mL UBC after brief challenges to microbial proxies were assessed; on day 9, the cells were succumbed to three different microbial insults (LPS, Poly I:C, and Zymosan). On day 10, measurements demonstrated a moderate accumulation of oxidative stress, conditional to each cell type. Thus, UBC plus microbe approach triggered pro-oxidant levels and cytokine production across different cell types and diminished phagocytic response by murine macrophages. Based on the results, ultrafine-PM exposure may impair inflammatory function in response to pathogenic infections. In summation, our findings indicated that additive nanosized UBC in combination with microbe-like challenges may compromise cellular behavior, suggesting potential ways by which inhalation of ultrafine-PM may contribute to or exacerbate poor pulmonary health.

Potential Impact Of Northern Resource Development On Aquatic Biota: Toxicity Of Chromium And Rare Earth Element Processing Reagent, So Yeon Choi

Theses and Dissertations (Comprehensive)

Chromite and rare earth element development was identified in the 2015 Canadian Federal budget as a significant opportunity, however, key data gaps exist regarding the environmental concerns related to these resource developments. Chromium is essential in the production of stainless steel, and no suitable substitute is known. Rare earth elements (REEs) are a series of metals that are composed of 15 lanthanides, as well as scandium and yttrium. Uses for REEs range from electronic devices (i.e. cell phones, computers, televisions) to magnets and controlling nuclear reactors. While commercial production of REEs signify a great economic opportunity for Canada, key data …

Negative Effects Of Common Herbicides On Non-Target Invertebrates, Debbi Albanese

College of Graduate Studies: Theses & Dissertations

Three herbicide formulations, Roundup® Ready to Use Weed and Grass Killer, Bayer Advanced Southern Weed Killer for Lawns and Pure 20% Vinegar Solution were directly applied to eggs of four species of butterflies, Danaus plexippus, Papilio cresphontes, Papilio polyxenes and Papilio troilus. Roundup and Bayer Advanced containing 2,4-D, mecoprop-p and dicamba significantly reduced hatch success in all four species. Lethal and sublethal effects of these herbicides on the earthworm, Eisenia andrei, was also examined. Direct contact by E. andrei with a heavy dose of the herbicides applied to tops of soil 24 hours prior was lethal to earthworms. …

The Value Of Chemical Defense: The Effects Of Toxin Milking On The Physical, Physiological, And Behavioral Performance Of Cane Toads (Rhinella Marina), Ryann Blennerhassett

Independent Study Project (ISP) Collection

Amphibians have cutaneous glands on their skin which produce a number of toxic compounds that serve as protection against predators and microorganisms. Cane toads (Rhinella marina) have large parotoid glands located on their shoulders to store toxins, many of which are derived from lipids and are thus energetically expensive to produce. I used a combination of field and laboratory studies to investigate behavioral and physiological consequences of toxin loss and replenishment in cane toads. In a cross-sectional study, free-ranging toads were euthanized and dissected to identify correlations between toxin content and morphology /physiology. Experimental manipulations (manually expressing toxin from glands) …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Investigating The Role Of Genomic Variation In Susceptibility To Environmental Chemicals Across Populations, Lindsay Adrian Holden

Dissertations and Theses

No two individuals are identical. This is true at the genetic level and at the phenotypic level. One of the traits that varies between populations is toxicant susceptibility: some individuals are sensitive to the effects of environmental chemical exposure, and others are resistant. This body of work aims to address the impact of genomic copy number variants (CNV)--large (>1 Kb) duplications or deletions across the genome--on the toxicant-susceptibility phenotype.

Herein copy number variants were characterized across three commonly used laboratory strains of zebrafish (Danio rerio) and mRNA expression phenotypes were identified in the same strains. It was found that …

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 …

Effects Of Radiation On Neurite Morphology And Cytoskeleton Structure, Melissa Sassman

Student Scholarship

Long-term manned space exploration to the moon, Mars, and other areas beyond Earth's protective magnetic field poses possible acute and late central nervous systems (CNS) risks. Of particular concern for astronauts is exposure to high atomic number, high energy particles known as HZE particles, a component of galactic cosmic radiation (GCR). Although NASA has radiation safety requirements, the possible effects of GCR and HZE particles on the central nervous systems of astronauts remains unknown. Understanding the risks and effects of galactic cosmic radiation and HZE particles on the central nervous system will allow for safer space exploration.

Additionally, and perhaps …

Forensic Markers Of Lampricide Toxicity In Oncorhynchsus Mykiss, Chris White

Theses and Dissertations (Comprehensive)

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used for decades to control invasive sea lamprey (Petromyzon marinus) populations in the Great Lakes, normally with little harm to other fish populations. However, due to the nature of lampricide treatments and the chemical properties of TFM, adverse effects to non-target fishes and non-target mortality occasionally occur. However, investigations of non-target mortality can be complex, particularly if fish deaths are not noticed immediately, due to decomposition of the carcasses. The objectives of this thesis were to expose rainbow trout (Oncorhynchsus mykiss) to TFM in order to: (i) identify forensic markers …