Toxicology Commons^™

Derivation Of Screening Benchmarks For Dietary Methylmercury Exposure For The Common Loon (Gavia Immer): Rationale For Use In Ecological Risk Assessment, David C. Depew, Niladri Basu, Neil M. Burgess, Linda M. Campbell

University Faculty Publications and Creative Works

The current understanding of methylmercury (MeHg) toxicity to avian species has improved considerably in recent years and indicates that exposure to environmentally relevant concentrations of MeHg through the diet can adversely affect various aspects of avian health, reproduction, and survival. Because fish-eating birds are at particular risk for elevated MeHg exposure, the authors surveyed the available primary and secondary literature to summarize the effects of dietary MeHg on the common loon (Gavia immer) and to derive ecologically relevant toxic thresholds for dietary exposure to MeHg in fish prey. After considering the available data, the authors propose three screening benchmarks of …

Physiologically-Based Pharmacokinetic Modeling Of Acetaminophen Metabolism And Toxicity, David M. Ng, Ali Navid

STAR Program Research Presentations

Acetaminophen is a common analgesic and antipyretic. Metabolism of acetaminophen and acetaminophen-induced liver necrosis are predicted using physiologically-based pharmacokinetic (PBPK) modeling. Pharmacokinetic means the model determines where the drug is distributed in the body over time. Physiologically-based means the anatomy and physiology of the human body is reflected in the structure and functioning of the model. Acetaminophen is usually safe and effective when taken as recommended, but consumption at higher levels may lead to liver damage. Additionally, other factors such as alcoholic liver disease, smoking, and malnutrition affect the maximum safe dose of acetaminophen.

Weaponizing Tear Gas: Bahrain’S Unprecedented Use Of Toxic Chemical Agents Against Civilians., Richard Sollom, Holly G. Atkinson

Publications and Research

The Bahraini government’s response to the early 2011 pro-democracy protests was brutal, systematic, and violent. In addition to birdshot and rubber bullets, government law enforcement attacked unarmed protestors with toxic chemical agents including tear gas. The government’s crackdown on the medical profession was especially harmful, as security forces arrested and detained doctors, raided health facilities, and obstructed patients from receiving necessary care. This report’s findings are based on field research that the authors conducted in Bahrain (April 2012) to investigate excessive use of force by law enforcement officials since June 2011—the end of Bahrain’s state of emergency. The medico-legal team …

Analysis Of Nanoparticle Exposure On Legionella Pneumophila Biofilm Morphology And Host-Bacteria Interactions, Tara Diane Raftery

All Theses

An increase in the amount of money spent on nanotechnology has led to an increase in funding to support nanoparticle (NP) research. Due to their stable, beneficial properties, NPs are found in daily consumer products such as bike frames, socks, cosmetics, and sunscreens. As a result of this, these NPs have the potential to enter the environment and interact with various organisms that play integral roles in the ecosystem as a whole. The effect that NPs have on aquatic systems is largely unknown and understudied. Biofilms are an important structural and functional part of aquatic ecosystems, and comprise various microorganisms …

Lipid Peroxides And Glutathione Status In Human Progenitor Mononuclear (U937) Cells Following Exposure To Low Doses Of Nickel And Copper, William Y. Boadi, Shalandus Harris, Justin B. Anderson, Samuel E. Adunyah

Chemistry Faculty Research

Effects of Cu2+, Ni2+ or Cu2+ + Ni2+ on lipid peroxide and glutathione (GSH) levels in U937 cells were investigated. Cells were treated with 0, 5, 10, and 20 µM of Cu2+ and/or Ni2+ and H2O2 (0.01 mM) and incubated for 24 hours at 37°C. Lipid peroxides were measured by the thiobarbituric acid assay (TBA). GSH intracellular levels were assayed by the GSH assay kit from EMD/Calbiochem (San Diego, California, USA). Cu2+ or Ni2+ significantly (P < 0.01) increased lipid peroxides in a dose-dependent manner, compared to controls. The effect was more pronounced for Cu2+, compared to the Ni2+-treated samples. Cu2+ + Ni2+ increased lipid peroxides in a significant (P < 0.001), dose-dependent manner, compared to Cu2+ or Ni2+ alone (i.e., ratio of 2.5:1-fold for combined versus single treatments, respectively). Cu2+ or Ni2+ significantly decreased GSH levels in U937 cells, with the effect being pronounced for Cu2+. Cu2+ + Ni2+ metal ions significantly (P < 0.001) depleted cells of GSH in a dose-dependent manner. Ethylene diamine tetraacetic acid (EDTA) at 50 or 100 µM moderately reduced the Cu2+- or Ni2+-induced effects on GSH levels. Interestingly, GSH levels generally decreased to half (except for the combined metal dose of 20 µM at 100 µM EDTA) of its level at the highest metal concentration tested for both the single or combined treatments. In conclusion, multiple exposures of cells to metal ions may be lethal to cells, compared to their single treatments.

Environmental Monitoring Of Chemicals In Swimming Pools In North And Northeast Houston, Ogochukwu Adaikpoh

Theses (Pre-2016)

N/A

Distribution, Elimination, And Biopersistence To 90 Days Of A Systemically Introduced 30 Nm Ceria-Engineered Nanomaterial In Rats, Robert A. Yokel, Tu C. Au, Robert Macphail, Sarita S. Hardas, D. Allan Butterfield, Rukhsana Sultana, Michael Goodman, Michael T. Tseng, Mo Dan, Hamed Haghnazar, Jason M. Unrine, Uschi M. Graham, Peng Wu, Eric A. Grulke

Pharmaceutical Sciences Faculty Publications

Nanoceria is used as a catalyst in diesel fuel, as an abrasive in printed circuit manufacture, and is being pursued as an antioxidant therapeutic. Our objective is to extend previous findings showing that there were no reductions of cerium in organs of the mononuclear phagocyte (reticuloendothelial) system up to 30 days after a single nanoscale ceria administration. An ~5% aqueous dispersion of citrate-stabilized 30 nm ceria, synthesized and characterized in-house, or vehicle, was iv infused into rats terminated 1, 7, 30, or 90 days later. Cageside observations were obtained daily, body weight weekly. Daily urinary and fecal cerium outputs were …

Arsenic Contamination In Groundwater In Vietnam: An Overview And Analysis Of The Historical, Cultural, Economic, And Political Parameters In The Success Of Various Mitigation Options, Thuy M. Ly

Pomona Senior Theses

Although arsenic is naturally present in the environment, 99% of human exposure to arsenic is through ingestion. Throughout history, arsenic is known as “the king of poisons”; it is mutagenic, carcinogenic, and teratogenic. Even in smaller concentrations, it accumulates in the body and takes decades before any physical symptoms of arsenic poisoning shows. According to the World Health Organization (WHO), the safe concentration of arsenic in drinking water is 10 µg/L. However, this limit is often times ignored until it is decades too late and people begin showing symptoms of having been poisoned.

This is the current situation for Vietnam, …

Evaluation Of Urinary Pesticide Biomarkers Among A Sample Of The Population In The United States, Alex Lance Lebeau

USF Tampa Graduate Theses and Dissertations

Pesticide use in the United States continues to attract negative public attention. In recent years, this attention has focused on the effects that chronic, low-level pesticides may have, especially on children and various sub-populations. Over the past decade, studies have attempted to correlate negative health effects with detections of pesticide biomarkers in biological media. The current research investigates biomarker of exposure levels in a sample of the United States population. Data from the 2001-2002 NHANES dataset (n=11,039) was evaluated. The detection frequency of urinary biomarkers of exposure and the geometric mean from the NHANES pesticide dataset (n=3,152) were determined. Of …

Cationic Amphiphilic Drug-Induced Autophagosome Accumulation Is Due To Autophagosome Sequestration Within Vimentin Intermediate Filament Networks Resulting In Prolonged Autophagosome Half-Life, Miriam Devorah Kleinman

Wayne State University Dissertations

Accumulations of autophagosomes and non-esterified cholesterol are

observed in several cell lines derived from lysosomal storage diseases,

including Niemann Pick Type C (NPC). The relationship between

autophagosome accumulation and lysosomal non-esterified cholesterol is

unclear. Exposure of murine hepatoma 1c1c7 cultures to the cationic

amphiphilic drugs (CADs) U18666A, imipramine and clozapine caused

lysosomal non-esterified cholesterol and autophagosome accumulation.

Measurement of LC3-II conversion in the presence of lysosomal inhibitors

bafilomycin A1 and NH4Cl, degradation of long-lived proteins, and

colocalization of GFP-LC3 and LAMP1 indicated an increase in

autophagosome synthesis without compensatory increase in clearance.

Autophagosome synthesis was blocked using 3-MA to monitor …

The Effect Of Cadmium Exposure On Repeat Swimming Performance And Recovery In Rainbow Trout (Oncorhynchus Mykiss), Brown Trout (Salmo Trutta) And Lake Whitefish (Coregonus Clupeaformis), Jessie L. Cunningham

Theses and Dissertations (Comprehensive)

Swim performance provides a measure of the integrated metabolic costs of sub-lethal exposure to stressors, including Cd. While the impacts to sustained swimming performance in Cd exposed fish have already been characterised, effects to repeat swimming ability have not. This thesis identifies the effects of sub-lethal waterborne Cd exposure on ionoregulatory function, repeat swimming ability, anaerobic metabolism and stress response in rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

Repeat swim trials included an initial swim to 85% of the U_crit of control fish and a recovery period …

Effects Of 17Α-Ethinylestradiol (Ee2) On Reproductive Endocrine Status In Mummichog (Fundulus Heteroclitus) Under Differing Salinity And Temperature Conditions, Esteban Gillio Meina

Theses and Dissertations (Comprehensive)

Waterborne exposure to 17α-ethinylestradiol (EE₂), a synthetic estrogen, has previously been shown to decrease reproductive endocrine status in the estuarine killifish or mummichog (Fundulus heteroclitus macrolepidotus; northern subspecies). To evaluate if variations in salinity or temperature holding conditions modify the effects of EE₂ on gonad size, plasma reproductive steroid levels, and gonadal steroidogenesis, mummichog were exposed in vivo for 14 days to 0, 50 and 250 ng/L EE₂ in 0, 16 and 32 ppt salinity at 18°C and to 0 and 250 ng/L EE₂ at 10, 18 and 26°C at 16 ppt salinity. …

The Chronic Toxicity Of Titanium Dioxide Nanoparticles To The Freshwater Amphipod Hyalella Azteca, Gurkirpal S. Malhi

Theses and Dissertations (Comprehensive)

There has been an increased use of metal-oxide nanoparticles in both commercial and consumer products. The use of these products and waste generated during manufacture may ultimately be released into the aquatic environment and the potential for these contaminants to cause impacts must be assessed. This study examines the effect of titanium dioxide (TiO₂) nanoparticles (NPs) on Hyalella azteca. Chronic toxicity exposures were conducted in 400mL of spiked test solution and contained 20 neonates. Samples collected for characterization of Ti in TiO₂ NP exposure solutions were digested using ammonium persulfate as an oxidizing agent and dissolved …

Analogues Of The Epoxy Resin Monomer Diglycidyl Ether Of Bisphenol F: Effects On Contact Allergenic Potency And Cytotoxicity, Niamh O'Boyle, Tamara Delaine, Kristina Luthman, Andreas Natsch, Ann-Therese Karlberg

Articles

Diglycidyl ethers of bisphenol A (DGEBA) and bisphenol F (DGEBF) are widely used as components in epoxy resin thermosetting products. They are known to cause occupational and non-occupational allergic contact dermatitis. The aim of this study is to investigate analogues of DGEBF with regard to contact allergy and cytotoxicity. A comprehensive knowledge of the structural features that contribute to the allergenic and cytotoxic effects of DGEBF will guide the development of future novel epoxy resin systems with reduced health hazards for those coming into contact with them. It was found that the allergenic effects of DGEBF were dependent on its …

A Survey Of Selected Pharmaceuticals And Personal Care Products In A Binational River And Their Effects On A Member Of Its Zooplankton Community, Plationus Patulus (Rotifera), Diana Angelica Martinez Gomez

Open Access Theses & Dissertations

The presence of 9 selected PPCPs (acetaminophen, caffeine, cotinine, codeine, fluoxetine, erythromycin, ciprofloxacin, sulfamethazine, and trimethoprim) was surveyed in water samples collected at four sites along the middle Rio Grande during two flow regimes (irrigation and non-irrigation). Water collection for PPCPs analyses were conducted from August 2010 through September 2011. Three of the sites were located upstream, in, and downstream of the El Paso, TX/Ciudad Juárez, MX metroplex. Site selection was based on their proximity to the metroplex and due to the fact that the Rio Grande in this region is an effluent receiver water system (IBWC, 2011). The fourth …

Studies On Waterborne Cadmium Exposure To Lymnaea Stagnalis In Varying Water Qualities And The Development Of A Novel Tissue Residue Approach, Nish M. Pais

Theses and Dissertations (Comprehensive)

Recent studies have shown that the use of bioaccumulation (tissue residues) as a predictor for toxic effects for metals is a flawed concept.Adams et al. (2010) suggested a novel tissue residue approach (TRA) in which bioaccumulation in resistant organismsis related to toxic effects in sensitive organisms. The goal of this thesis was to test these assumptions in relation to Cd exposure using the great pond snail, Lymnaea stagnalis by developing and improving the understanding of Cd accumulationin aquatic invertebrates.

The relationship between Cd bioaccumulation and its toxicity was studied in L. stagnalisusing acute (96h) and chronic (one month) …

Investigations Of Oxidative Stress Effects And Their Mechanisms In Rat Brain After Systemic Administration Of Ceria Engineered Nanomaterials, Sarita S. Hardas

Theses and Dissertations--Chemistry

Advancing applications of engineered nanomaterials (ENM) in various fields create the opportunity for intended (e.g. drug and gene delivery) or unintended (e.g. occupational and environmental) exposure to ENM. However, the knowledge of ENM-toxicity is lagging behind their application development. Understanding the ENM hazard can help us to avoid potential human health problems associated with ENM applications as well as to increase their public acceptance. Ceria (cerium [Ce] oxide) ENM have many current and potential commercial applications. Beyond the traditional use of ceria as an abrasive, the scope of ceria ENM applications now extends into fuel cell manufacturing, diesel fuel additives …

Classification Of Plants According To Their Heavy Metal Content Around North Mara Gold Mine, Tanzania: Implication For Phytoremediation, N. Mganga, Mlk Manoko, Z. K. Rulangaranga

Tanzania Journal of Science

Plants like other living organisms respond differently under different environmental conditions. An elevated level of heavy metals is one of the stresses which results into three classes of plants depending on their heavy metal content. The classes of plant species according to their accumulated heavy metals around North Mara Gold Mine were not known. To study such classes, a line transect of 700m long was established opposite the gold mine wastes. A total of eight sampling points were systematically established each after every 100m in that transect. Fifteen plant species were sampled; at least one species per sampling point. Approximately …

Degradation Of Atrazine By White Rot And Soil Fungi, Gerald Presley

Undergraduate Honors Theses

The widespread use of atrazine in agriculture has lead to an abundance of this toxic chemical in the environment. Fungi that have the ability to degrade atrazine into less toxic products have been identified and used in the remediation of atrazine. In this study atrazine degradation in a defined liquid media was characterized in a diverse group of white rot basidiomycete and deuteromycete soil fungi. Atrazine did not have an effect on fungal growth although each species produced a different amount of biomass in culture. Statistical analysis showed that biomass production was an important factor in determining the amount of …

2012 Barley Variety Sowing Guide For Western Australia, Blakely Paynter, Andrea Hills, Harmohinder Dhammu

Bulletins 4000 -

This variety guide is designed as a quick reference to help growers determine which barley variety to grow in their region. It provides domestic and international market feedback, relative grain yield comparisons, disease ratings, agronomic information and herbicide tolerance ratings for all malting barley varieties, the new food variety and selected feed varieties.