Toxicology Commons^™

Promoting Healthier Treatment Outcomes In Obese Cancer Patients Taking High Dose Methotrexate, Carly Dell'ova

Walden Dissertations and Doctoral Studies

Cancer and obesity rates continue to rise, creating enormous public heath burdens to the individual and at the national and global levels, reducing quality of life, and increasing spending. Moreover, the relationships between cancer and obesity are not well understood. A commonly used chemotherapy for several types of cancer is high dose methotrexate (HDMTX). Along with chemotherapy, especially at high doses, comes toxicity to specific organs and the entire body. However, limited research has been conducted on obese cancer patients as they are often excluded from clinical studies. Practitioners need to better understand how to dose these patients to provide …

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …

Hepatic Transcriptomic Assessment Of Sprague Dawley Rats In Response To Dietary Perfluorobutane Sulfonate (Pfbs) Ingestion, Isaac Appiah

College of Graduate Studies: Theses & Dissertations

Perfluorobutane sulfonate (PFBS) is a short-chain PFAS that is considered to be a less toxic replacement for the rather more toxic long-chain perfluorooctane sulfonate (PFOS). Its numerous industrial applications and widespread presence in the environment have raised environmental and health concerns because of growing evidence associating adverse health effects and certain liver diseases to PFBS exposure. The study goal was to investigate whether dietary ingestion of PFBS would induce liver injuries, damage, inflammations, and oxidative stress. To achieve these goals, Sprague-Dawley rats were assigned into three PFBS dietary treatment groups (0, 50, and 100 PPM) for 11 weeks. After this …

Acute Copper (Cu) Toxicity In Dragonfly Naiads (Insecta: Odonata), Jeff M. Simpson

Department of Entomology: Distance Master of Science Projects

The objective of this study was to examine the effects copper (Cu) on mortality within a pair of test groups of naiads in the order Odonata, and to replicate previous observations regarding their potential uses as indicators for water quality. Few past studies have examined toxicity within relation to the odonates. It has been suggested that this order may contain valuable model organisms (Tollett et al., 2008). Very little focus has been given to odonates as bioindicators, with the few studies done being performed on species that would typically inhabit lentic environments (Trevino, 1999). Similarly, the test subjects for this …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

Gut-Lung Axis Of The Microbiome Alterations After Ultrafine Particles And Ozone Inhalation, Md Habibul Hasan Mazumder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Air pollution poses a significant threat to public health. It is a mixture of particulate matter, gaseous substances, and other secondary substances. Despite epidemiological research indicating the interactive effects of various components of air pollution, existing studies and regulatory limits often focus on single-exposure scenarios. The emerging understanding of the microbiome’s role in regulating immune response, metabolism, and pathophysiology of various diseases points towards interactions between environmental exposures and microbial dysbiosis. In this dissertation, mice were exposed to relevant deposited doses of carbon black (CB) and ozone (O3), and lung inflammation as well as the lung-gut axis of the microbiome …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Quantification Of Phosphatidylethanol In Whole Blood And Dried Blood Spots By Lc-Ms/Ms, Elizabeth Yulianto

Student Theses

Phosphatidylethanol (PEth) is an alcohol biomarker that provides a longer window of detection than direct alcohol measurement or other common alcohol metabolites, like ethyl glucuronide. PEth has become useful in assessing drinking history, such as for alcohol-withdrawal treatment, organ transplant settings or prenatal alcohol exposure determination. A method was developed and validated to quantify PEth 16:0/18:1 and 16:0/18:2 in whole blood and dried blood spots (DBS) by liquid chromatography tandem mass spectrometry (LC-MS/MS). The whole blood method was applied to 149 samples from pregnant women, elucidating possible prenatal alcohol exposure. Fifty μL whole blood and 12.7 mm whole punches from …

Inhibition Of Rad18 By Arsenic, Lindsay B. Volk

Biomedical Sciences ETDs

Arsenite exposure leads to the retention of UV-induced DNA damage, thus burdening translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and is implicated in homologous recombination. It contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Results from this study reveal arsenite binding to both zinc fingers of Rad18 and a corresponding loss of domain function. Importantly, arsenite inhibited Rad18 RING-dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage. Further analysis demonstrated multiple effects of arsenite, including the reduction in the nuclear localization and UV-induced chromatin recruitment …

Hepatocyte-Hepatic Stellate Cell Axis In Potentiation Of Alcohol And Hiv-Induced Liver Injury, Moses O. New-Aaron

Theses & Dissertations

Human Immunodeficiency Virus (HIV) remains a global threat, with approximately 38.4 million active infections and 33 million HIV-related deaths since the first case. While many may be tempted to think of HIV as a relic of the past, emerging data suggests otherwise. By the end of 2021, approximately 1.5 million HIV incidences and 650 000 mortalities were reported globally. The etiologies of HIV-related mortality are numerous. Liver disease is one of the leading etiologies of HIV-related mortality, especially in recent times of antiretroviral therapy (ART)-induced longevity among people living with HIV (PLWH). While co-infections with hepatotropic viruses notoriously contribute to …

Étude Visant À Mieux Guider L’Évaluation Des Risques Des Travailleurs Exposés Aux Nanoparticules (Np) : Existe-T-Il Différentes Propriétés Inflammatoires Des Np Liées Au Sexe?, Marion Vanharen, Abdelaziz Saafane, Alexanne Léveillé, Thomas Mahbeer, Denis Girard

Rapports de recherche scientifique

Les nanotechnologies offrent un important potentiel d’exploitation dans des secteurs industriels variés, pour lequel les bénéfices financiers ne sont pas négligeables. À l’instar des provinces canadiennes et de nombreux pays industrialisés, le Québec voit un nombre grandissant de compagnies produisant des nanomatériaux et des nanoparticules (NP) se développer, sans oublier celles qui introduisent de plus en plus de NP dans leurs produits. Le nombre de travailleurs québécois œuvrant dans la fabrication et dans la synthèse des NP augmentera dans les années à venir. De plus, le nombre de travailleurs appelés à manipuler et à transformer des NP dans les domaines …

Effects Of Microcystin-Lr On Channel Catfish (Ictalurus Punctatus) Susceptibility To Microbial Pathogens (Aeromonas Hydrophila And Edwardsiella Piscicida), Alison Marchant

Theses and Dissertations

Microcystin-LR is a hepatotoxin produced by cyanobacteria. Aeromonas hydrophila and Edwardsiella piscicida infections are leading causes of losses in market-sized channel catfish (Ictalurus punctatus). These older fish should have natural immunity in place and a predisposing factor is likely a prerequisite for these disease outbreaks. While microcystin-LR rarely causes mortality in warm-water aquaculture, we believe it may be a predisposing factor that leads to bacterial disease outbreaks during the summer months due to its ability to damage the liver. Our study investigated microcystin-LR’s effects on channel catfish susceptibility to these pathogens. We found that a sublethal dose of microcystin-LR induced …

Quantifying The Toxicological Effects Of The Organic Uv Filters Avobenzone And Homosalate On Acropora Cervicornis, Samantha F. Buckley

All HCAS Student Capstones, Theses, and Dissertations

Reports of the environmental effects of organic UV filters such as oxybenzone have led to the marketing of “reef-safe” sunscreen ingredients, including avobenzone and homosalate. Avobenzone provides broad-spectrum UV protection which blocks higher wavelength UV rays, the leading cause of aging and skin cancer. However, as polycyclic aromatic hydrocarbons (PAHs), organic UV filters have similar structures to crude oil and estrogens, some of which have been labeled endocrine disrupters. Common in personal care products, UV filters enter marine ecosystems via wastewater effluent and swimmers. Significant stress and mortality have been observed in juvenile and some adult scleractinian corals after exposure …

Investigation Of Human N-Acetyltransferases (Nat1 And Nat2) Genetic Polymorphisms In Susceptibility To Aromatic Amine And Alkylaniline Genotoxicity., Mariam Habil

Electronic Theses and Dissertations

Arylamine N-acetyltransferases, NAT1 and NAT2, catalyze the detoxification and/or activation of carcinogens. Single nucleotide polymorphisms or SNPs result in different human NAT1 and NAT2 genotypes. We hypothesize that different NATs alleles will impact levels of N-acetylation, HPRT mutations, DNA damage and oxidative stress induced by carcinogens. NER-deficient Chinese hamster ovary (CHO) cells transfected with human CYP1A2 and NAT1*4, NAT1*14B, NAT2*4, NAT2*5B or NAT2*7B have been used to investigate N-acetylation of benzidine, β-naphthylamine (BNA), and 4, 4’-methylene bis (2-chloroaniline) (MOCA) as aromatic amines and 3,4-dimethylaniline (3,4-DMA) as one of alkylanilines and their associated toxicity. Our …

Developmental Effects Of Chronic Low-Level Arsenic Exposure In Mouse Embryonic Stem Cells And In Human Induced Pluripotent Stem Cells, M. Chiara Perego

All Dissertations

Arsenic is an environmental contaminant commonly found in food and drinking water. Exposure to arsenic during embryonic development has been linked to reduced muscle growth, disrupted muscle development and locomotor activity, impaired neurodevelopment, reduced IQ, impaired memory and learning deficits. While the mechanisms responsible for developmental changes following in utero exposure to arsenic are not well known, one possibility is that arsenic might disrupt proper cellular differentiation. Therefore, we aimed to investigate the mechanisms by which arsenic exposure could alter stem cell differentiation into neurons.

First, we continuously exposed P19 mouse embryonic stem (ES) cells to 0.1 μM (7.5 ppb) …

The Impact Of Pharmacogenetics On Oral Fluid Steady State Drug Testing Results, Aliya D. Lewis

Student Theses

Pharmacogenetics refers to the relationship between phenotypic variation in metabolism and response to certain drugs. The interface of pharmacogenetics and forensic toxicology is not well explored. A major component of the opioid metabolic pathway has to do with a family of cytochromes called cytochrome P450 (CYP450). CYP450 refers to a general family of enzymes capable of catalyzing the oxidative biotransformation of lipophilic substances, CYPs are further categorized into families and sub-families (Roller, 2015; Zanger & Schwab, 2013). The gene CYP2D6 belongs to the CYP2 family which is responsible for the biotransformation of xenobiotics. This study looked at the effect of …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Effects Of Titanium Dioxide Nanoparticle Injections On Tissue Function And Morphology In Goldfish (Carassius Auratus), Bryan Joel Patterson

Graduate Theses

Fish gills are sensitive to a variety of environmental factors because they regulate the exchange of oxygen and ions between the fish and the external environment. This study examined the effects of polyacrylic acid (PAA) coated titanium dioxide nanoparticle injections (TiO₂ NPs) on goldfish (Carassius auratus) over 14 days. Following the experimental period, we examined gill histological samples and looked for signs of an inflammatory response through blood glucose levels and relevant gene expression. TiO₂ injected fish developed a more robust ILCM (interlamellar cell mass) compared to the non-injected controls, which remained elevated over 14 days post injection. …

The Effect Of Volatile Organic Compounds On Endothelial Function And Atherogenesis., Samantha Mcfall

Electronic Theses and Dissertations

Volatile organic compounds (VOCs) are a group of pervasive air pollutants that are released into the atmosphere from both anthropogenic and environmental sources. Recent epidemiological studies suggest that exposure to various VOCs is associated with an increased risk of cardiovascular disease. However, the relationship between VOCs and cardiovascular disease is not well-studied. Using animal models and three select VOCs, benzene, xylene, and trichloroethylene, we studied the effects of VOCs on endothelial injury and benzene-induced atherogenesis. We found that exposure to benzene and xylene increased circulating endothelial microparticles, depleted progenitor cells, and increased platelet activation. Following the exposure to the representative …

Acknowledgment Of Reviewers

Journal of Food and Drug Analysis

No abstract provided.