Toxicology Commons^™

Age-Related Host Factors Regulate Lung Cancer Progression., John Caleb Greenwell

Electronic Theses and Dissertations

Cancer is largely a disease of the elderly. In the United States alone, 87% of all cancers in 2017 will be diagnosed in individuals aged 50 years or older. Among them, lung cancer is the deadliest, accounting for 1 in 4 cancer deaths. The 5-year survival rate is below 20%, a number which has not changed substantially over the past several decades. This underscores a desperate need for new strategies in prevention, early detection and treatment of this deadly disease. While tobacco use is unquestionably the number one risk factor for the development of lung cancer, the majority of diagnoses …

Toxicity And Mitochondrial Delivery Of Flavonol-Based Carbon Monoxide-Releasing Molecules, Hector Jose Esquer Heredia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Despite the reputation of carbon monoxide (CO) as a silent killer, new evidence suggests that this gaseous molecule has anti-inflammatory, anti-cancer and vasoprotective properties. Unfortunately, little is known about the role of CO in the body. However, proteins present in mitochondria are believed to be important targets. We previously synthesized a class of novel and structurally modifiable flavonol-based CO-releasing molecules (CORMs). Flavonols are commonly found in fruits and vegetables. The base structure, Flav-1, is fluorescent, exhibits low toxicity, and releases CO after exposure to visible light. Previous reports indicate that addition of a triphenylphosphonium (TPP) tail allows chemical structures to …

Activation Des Éosinophiles Humains Par Des Nanoparticules, Denis Girard, Maxime Marion-Murphy

Rapports de recherche scientifique

L’économie du Canada, comme celle de bien d’autres pays industrialisés, bénéficie du développement des nanotechnologies dont le fort potentiel peut être exploité dans plusieurs secteurs industriels. Un nombre croissant d’entreprises québécoises de production de nanoparticules (NP) est d’ailleurs déjà implanté et tout porte à croire que d’autres emboîteront le pas dans les années à venir. Ce faisant, non seulement le nombre de travailleurs œuvrant dans la fabrication et la synthèse des NP augmentera sensiblement, mais également le nombre de ceux qui seront appelés à en manipuler et à en transformer dans les domaines des nanotechnologies en général. Une des conséquences …

A Historical Assessment Of Asbestos Exposure, Abatement Methods And Containment Efficacy During Asbestos Containing Material Removal Activities At A Large Federal Facility, Daniel A. Newfang

USF Tampa Graduate Theses and Dissertations

Asbestos sampling and monitoring data, starting from 2003, located in a large federal facility’s Asbestos Air Database Management (AADM) repository will be queried and analyzed on airborne asbestos fiber concentrations generated from abatement activities of asbestos-containing materials (ACM) and asbestos-containing building materials (ACBM). Historically, concerns expressed by personnel outside of the containment areas, whether adjacent to or quite a distance from the asbestos abatement activities present operational challenges for the project manager, potential angst and uneasiness to personnel residing next to the abatement activity as well as programmatic concerns to the building/facility managers. The concerned individuals working outside the abatement …

Multigeneration Effects Of Chronic Exposure To Polycyclic Aromatic Hydrocarbons In Gulf Killifish (Fundulus Grandis), Andrea Yammine

LSU Master's Theses

The goal of this study was to examine potential adaptation within two generations of Gulf killifish exposed to polycyclic aromatic hydrocarbons (PAH) while also investigating the use of mucus as an effective and non-lethal alternative to determine concentrations of 11-ketotestosterone (11-KT) and vitellogenin (VTG) of F. grandis. Multiple biomarkers were used to assess adaptation within these fish, such as lysozyme (enzyme critical in innate immunity), and 11-ketotestosterone and vitellogenin (endocrine hormones often affected by PAHs).

Mucal concentrations of 11-KT and VTG were determined and evaluated for effectiveness through comparative assays with blood plasma. This method was then applied to …

Effects Of Carboxylated Nanodiamonds On Macrophages During And After Differentiation, Maisoun E. Bani Hani

Biological Sciences Theses & Dissertations

Nanodiamonds (ND) are a carbon-based nanomaterial that are increasingly being proposed for developing novel imaging techniques, as carriers of biomolecules and therapeutic drugs, as coatings for implants, and for other biomedical applications. The exceptional chemical, mechanical, and optical properties of ND make this material suitable in a wide range of fields. The application of ND in the biomedical field is attractive but requires more in-depth investigation into the safety of ND and its interactions with different cells and systems. The effects of ND on the immune system are not fully understood or investigated and there are several controverting reports regarding …

Protective Effect Of Beta-Sitosterol Against Ethanol Toxemia, Dakota Cooper, April Boucher-Zamzo

Journal of Undergraduate Research at Minnesota State University, Mankato

Herbal medications have no indications of interactions with alcohol on their labels. There has been at least one clinical finding that saw palmetto with active ingredient beta-sitosterol used for enlarged male prostates caused pancreatic damage. This study with 20 male mice hypothesized that ethanol would increase the toxicity of beta-sitosterol. It was found that mice dosed by gavage with 0.1 ml of 95 proof ethanol died starting at the second dose and increased to 100% by the sixth dose (unexpected based on literature). 60-microgram injections of beta-sitosterol prevented deaths in 80% of the mice past the sixth dose opposite to …

Inhibition Of Post-Transcriptional Steps In Ribosome Biogenesis Confers Cytoprotection Against Chemotherapeutic Agents In A P53-Dependent Manner, Russell T Sapio, Anastasiya N Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J Manna, Natalie Minkovsky, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The p53-mediated nucleolar stress response associated with inhibition of ribosomal RNA transcription was previously shown to potentiate killing of tumor cells. Here, we asked whether targeting of ribosome biogenesis can be used as the basis for selective p53-dependent cytoprotection of nonmalignant cells. Temporary functional inactivation of the 60S ribosome assembly factor Bop1 in a 3T3 cell model markedly increased cell recovery after exposure to camptothecin or methotrexate. This was due, at least in part, to reversible pausing of the cell cycle preventing S phase associated DNA damage. Similar cytoprotective effects were observed after transient shRNA-mediated silencing of Rps19, but not …

Rxtx And Micromedex, Shawn Hendrikx, Kelly Hatch

Western Libraries Publications

No abstract provided.

Enemy Exacerbation: Effects Of Predator Stress On Sulfate Lethality In Freshwater Amphipods (Gammarus Minus), Trevor Chapman

Electronic Theses and Dissertations

Predator cues can influence how aquatic organisms respond to anthropogenic contaminants. This study examined the effects of predator cues on behavior, metabolic rate, and sulfate (as Na₂SO₄) toxicity in amphipods (Gammarus minus). Predator cues included alarm cue (macerated conspecifics) and kairomone from mosquitofish (Gambusia affinis). Amphipods decreased activity and increased time in refuge when exposed to alarm cue, and increased time in refuge when exposed to kairomone. While median lethal concentrations (96-h LC₅₀) were not influenced by predator cues, analysis of dose response curves indicated that kairomone exposure increased amphipod …

Novel Insight Into The Liver-Lung Axis In Alcohol-Enhanced Acute Lung Injury., Lauren G. Poole

Electronic Theses and Dissertations

Background. Individuals who chronically abuse alcohol are almost 4 times more likely to develop Acute Respiratory Distress Syndrome (ARDS), the most severe form of Acute Lung Injury (ALI), but the mechanisms by which alcohol abuse sensitizes the lung to injury are poorly understood. However, the lung appears to share many parallel mechanisms of injury with the liver- a primary target of alcohol abuse. The overarching goal of this dissertation was therefore to expand on established mechanisms of alcohol-induced liver injury to ask innovative questions about mechanisms of alcohol-enhanced acute lung injury, as well as to develop new tools that may …

The Comparative Cytotoxicity And Genotoxicity Of Hexavalent Chromium In Humans And Sea Turtles., Rachel M. Speer

Electronic Theses and Dissertations

Monitoring the health effects of environmental contaminants can be achieved using sentinel species as models. Leatherback sea turtles (Dermochelys coriacea) are an endangered marine species that may experience prolonged exposures to environmental contaminants including hexavalent chromium [Cr(VI)]. While Cr(VI) has been identified as a known human carcinogen, the health effects in marine species are poorly understood. In this study the cytotoxic and genotoxic effects of particulate and soluble Cr(VI) were assessed in leatherback lung cells and compared to those in human lung cells. Cr(VI) induced a concentration-dependent increase in cytotoxicity and genotoxicity in leatherback lung cells indicating Cr(VI) …

Sphingolipids In Models Of Kidney Disease And Injury., Tess V. Dupre

Electronic Theses and Dissertations

Acute kidney injury (AKI), resulting from cisplatin, remains an obstacle in the treatment of cancer. Cisplatin-induced AKI involves cell death pathways regulated by sphingolipids such as ceramide and glucosylceramide. Results indicate that cisplatin-treated mice had increased levels of ceramide and hexosylceramide. Pre-treatment of mice with inhibitors of ceramide synthesis prevented accumulation of ceramide and hexosylceramide in the renal cortex and attenuated cisplatin-induced AKI. To determine the role of ceramide metabolism to hexosylceramides in kidney injury, we treated mice with an inhibitor of glycosphingolipid synthesis. Inhibition of glycosphingolipid synthesis attenuated the accumulation of the hexosylceramide and exacerbated ceramide accumulation in the …

Distribution Of Polybrominated Diphenyl Ethers Among Demographic Categories, Giorvanni Merilis

USF Tampa Graduate Theses and Dissertations

Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used within the United States in various products such as plastics, electronics, textiles and furniture. With an increase in production and usage, PBDEs have recently emerged as a contaminant of concern. Due to their chemical structure, PBDEs have the propensity to bioaccumulate in mammals. In fact, elevated PBDE concentrations have been recorded in human breast milk. Due to the potential widespread exposure to PBDEs, this study investigates human blood concentrations of PBDEs generated through the 2003-2004 National Health and Nutrition Examination Survey. Through the use of statistical modeling, a comparison of mean …

Growth And Survival Of Salamanders Exposed To Different Formulations Of Glyphosate-Based Herbicide, Jessica Johnson

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations have been experiencing rapid declines worldwide in the past few decades. There are many proposed causations, including the use of agricultural chemicals such as herbicides. Glyphosate based herbicides are one of the most widely used herbicides. This study looks at the effects of different brands of glyphosate-based herbicides, including those intended for aquatic use, on the survival and growth of axolotl salamander larvae. Out of four brands of glyphosate herbicide (Aquamaster, Aquaneat, Helosate plus, and Roundup Pro), the survival rates of Roundup Pro were the lowest. Most mortality occurred between the 3 mg/L and 6 mg/L concentrations, during …

A Validation Of The Detection Of Barbiturates In Hair By Elisa, Alisa M. Valentino

Student Theses

An original method to extract and detect barbiturates, specifically secobarbital, in hair by enzyme-linked immunosorbent assay (ELISA), has been developed. Drug-free hair specimens were fortified with an exaggerated amount of secobarbital to produce a homogeneous, true positive sample to be utilized to test the drug extraction efficiency from hair. Drug extraction using hair extraction buffer (HEB) from Immunalysis was compared to a base digestion using 1M NaOH. After LCMS/MS analysis, HEB extraction was deemed a successful method for extracting barbiturates from hair. Using this method, the Barbiturates Direct ELISA Kit from Immunalysis was evaluated for its potential use in the …

Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman

Dissertations, Theses, and Capstone Projects

There is a long history of damage to natural ecosystems from environmental pollution. Many environmental contaminants are man-made and have been released with abandon over the last 100 years including dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs). These chemicals act on similar cellular processes and cause skin lesions, cancer, learning disabilities and reproductive problems in many vertebrates. There are many studies exploring various aspects of TCDD and PCB exposure on model and wild organisms. Few studies however, have compared effects of PCB mixtures on ecosystems to effects of individual PCBs in the lab. The first aim of this thesis is …

Quantitative Analysis Of Opioids And Cannabinoids In Wastewater Samples, Alethea Jacox

Student Theses

Wastewater-based epidemiology is an innovative approach that uses the analysis of human excretion products in wastewater to obtain information about exposure to drugs in defined population groups. We developed and validated an analytical method for the detection and quantification of opioids (morphine, oxycodone, hydrocodone, oxymorphone and hydromorphone), and cannabinoids (9-tetrahydrocannabinol, 11-nor 9-carboxy- tetrahydrocannabinol (THCCOOH) and THCCOOH-glucuronide) in raw influent wastewater samples by ultra-high performance liquid chromatography-tandem mass spectrometry. Method validation included linearity (5–1 000 ng/L for opioids, 10–1 000 ng/L for cannabinoids), imprecision (<21.2%), accuracy (83%–131%), matrix effect (from –35.1% to –14.7%) and extraction efficiency (25%–84%), limit of detection (1–5 ng/L) and quantification (5–10 ng/L) and auto-sampler stability (no loss detected). River, sewage overflow and wastewater samples were collected in triplicate from different locations in New York City and stored at -20 C until analysis. River water samples were negative for all the compounds. Water from sewage overflow location tested positive for morphine (10.7 ng/L), oxycodone (4.2–23.5 ng/L), oxymorphone (4.8 ng/L) and hydromorphone (4.2 ng/L). Wastewater samples tested positive for morphine (133.0– 258.3 ng/L), oxycodone (31.1– 63.6 ng/L), oxymorphone (16.0–56.8 ng/L), hydromorphone (6.8–18.0 ng/L), hydrocodone (4.0– 12.8 ng/L) and THCCOOH (168.2– 772.0 ng/L). This method is sensitive and specific for opioids and marijuana determination in wastewater samples.

Evaluation Of Perfluorohexane Sulfonate (Pfhxs) Exposure To Risk Of Liver Disease Caused By High Fat Fructose Diet, Dwight C. Anderson

Senior Honors Projects

Perfluorohexane sulfonate (PFHxS) has been used in products as surfactants[AS1] . These products include fluoropolymers and as protective and water-resistant coatings to different materials such as carpets, paper, and textiles. Also, evidence of PFHxS exposure has been reported in firefighters who use certain film forming foams. Current investigations have shown widespread exposure to PFHxS in the environment, specifically in drinking water. There has also been evidence of PFHxS accumulation in humans, with a half-life lasting several years.

PFHxS is one of several perfluoronated alkyl substances (PFAS). Other PFASs are considered to be hepatotoxic in rodents and potentially in humans. Studies …

Mercury Concentrations In Snowy Plovers And Sediments Of Their Breeding Environments In The Southern Great Plains, Laura Duffie

Electronic Theses and Dissertations

Western snowy plovers (Charadrius nivosus) are philopatric shorebirds sporadically distributed during the breeding season at saline lake and alkali flat breeding environments of the Southern Great Plains (SGP) of Oklahoma, New Mexico, and Texas. The major conservation threat to interior snowy plovers breeding on the SGP derives from anthropogenic modification of breeding environments. The SGP is one of the most intensively cultivated regions in the world, and excessive groundwater mining and resulting deterioration of artesian spring flows reduces site quantity and quality critical for regional successful nesting. Most saline lakes now primarily receive freshwater inputs via irregular precipitation …