Toxicology Commons^™

Impact Of Zinc Oxide Nanoparticles On Green Pea Plant & Seed Quality And Effects On Physiological Traits Of Green Peas, Corn, And Zucchini By Silver Nanoparticles, Arnab Mukherjee

Open Access Theses & Dissertations

The production and use of numerous engineered nanomaterials (ENMs) have increased exponentially over the past decade. Nanoparticles (NPs), ENMs possessing diameter between 1-100 nm, (NPs), are widely used in many applications. Worldwide consumption of NPs has increased their possible release into the environment. This, in turn, has elevated the extent of the potential impacts of NP exposure to living and non-living organisms. This is why the assessment of the impact of NPs on different environmental components, especially on plants, the producer in the food web, has become a very important aspect of nano-ecotoxicology. However, studies focusing on phytotoxicity and effects …

Concern-Driven Integrated Toxicity Testing Strategies For Nanomaterials - Report Of The Nanosafety Cluster Working Group 10, Hugh Byrne, Agnes G. Oomen, Peter M.J. Bos, Teresa F. Fernandes, Kerstin Hund-Rinke, Diana Boraschi, Karin Aschberger, Stefania Gottardo, Frank Von Der Kammer, Dana Kühnel, Danail Hristozov, Antonio Marcomini, Lucia Migliore

Articles

Bringing together topic-related European Union-(EU)-funded projects, the so-called “NanoSafety Cluster” aims at identifying key areas for further research on risk assessment procedures for nanomaterials (NM). The outcome of NanoSafety Cluster Working Group 10, this commentary presents a vision for concern-driven integrated approaches for the (eco-)toxicological testing and assessment (IATA) of NM. Such approaches should start out by determining concerns, i.e. specific information needs for a given NM based on realistic exposure scenarios. Recognized concerns can be addressed in a set of tiers using standardized protocols for NM preparation and testing. Tier 1 includes determining physico-chemical properties, non-testing (e.g. structure …

Toxic And Repellent Effects Of Pyrethroids Used In Orchards On The Honey Bee, Apis Mellifera L. (Hymenoptera: Apidae), Erin M. Ingram

Department of Entomology: Dissertations, Theses, and Student Research

Managed honey bee colonies provide valuable pollination services and are rented by fruit orchards to improve fruit quality and yield. The placement of colonies in this agricultural setting increases the possibility of exposure to pyrethroids used for broad-spectrum pest control in orchards. Although highly toxic to bees, pyrethroids are believed to pose a relatively low hazard due to their low application rates in the field as well as their contact repellent properties. Previous studies have noted a decrease in foraging visits following pyrethroid application possibly preventing bees from acquiring a lethal dose in the field.

This research quantified behaviors associated …

Importance Of Clinical Toxicology Teaching And Its Impact In Improving, Nadeem Ullah Khan, Jabeen Fayyaz, Uzma R. Khan, Asher Feroze

Department of Emergency Medicine

Objective: To assess the impact of a one-day clinical toxicology workshop in improving knowledge.
Methods: A one-day clinical toxicology workshop was conducted as a pre-conference workshop of the Annual Emergency Medicine Conference at the Aga Khan University Hospital, Karachi, in April 2012. The course was composed of poisoning-related common clinical scenarios. The pre-test and post-test understanding was used to assess the impact of the course in improving knowledge. The participants also evaluated the workshop as a whole thorough written evaluation forms. SPSS 19 was ued for statistical analysis of the data.
Result: There were 22 participants in the course. The …

High Dose, Variable Length, N-Acetylcysteine (Hinac) Therapy For Late-Presenting Acetaminophen Poisoning, Jessica K. Eygnor Do, Suprina Dorai Md, Philip W. Moore Do, J Ward Donovan Md, Keith K. Burkhart Md

Department of Emergency Medicine

No abstract provided.

Immunological And Reproductive Health Assessment In Herring Gulls And Black-Crowned Night Herons In The Hudson-Raritan Estuary, Keith A. Grasman, Kathy R. Echols, Thomas M. May, Paul H. Peterman

University Faculty Publications and Creative Works

Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in …

Atrazine And Nitrate In Public Drinking Water Supplies And Non-Hodgkin Lymphoma In Nebraska, Usa, Martha G. Rhoades, Jane L. Meza, Cheryl L. Beseler, Patrick J. Shea, Andy Kahle, Julie M. Vose, Kent M. Eskridge, Roy F. Spalding

School of Natural Resources: Faculty Publications

A secondary analysis of 1999–2002 Nebraska case-control data was conducted to assess the risk of non-Hodgkin lymphoma (NHL) associated with exposure to nitrate- and atrazine-contaminated drinking water. Water chemistry data were collected and weighted by well contribution and proximity of residence to water supply, followed by logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). We found no association between NHL risk and exposure to drinking water containing atrazine or nitrate alone. Risk associated with the interaction of nitrate and atrazine in drinking water was elevated (OR, 2.5; CI, 1.0–6.2). Risk of indolent B-cell lymphoma was higher …

Toxicological Effects Of Cerium Oxide Nanoparticle Aggregates On Caenorhabditis Elegans, Steven N. Rogers

Theses, Dissertations and Capstones

Assessing the toxicity and unique reactivity of nanoparticles in biological systems has become an relevant and quickly growing area of environmental toxicology research. The broad use of nanoparticles in industrial and commercial commodities results in exposure of these nano-compounds to the environment, the ecosystems, and humans. While previous data has suggested that cerium oxide (CeO₂) nanoparticles are relatively safe to cultured cells much less is known about the potential toxicity of these materials at the organismal level. In this study we employed transgenic Caenorhabditis elegans (C. elegans) strains to assess the toxicity of CeO₂ nanoparticles under “real-world” …

Linking Environmental Toxicant Exposure To Diabetes Susceptibility, Jannifer Beth Tyrrell

Wayne State University Dissertations

An important and unresolved question in the environmental health field is whether exposure to common environmental toxicants, such as dioxin and heavy metals like Pb, increase the risk of developing diabetes, especially in combination with other common metabolic stressors such as obesity.

Previous studies suggested that dioxin exposure increased peripheral insulin resistance but did not appear to cause fasting hyperglycemia or elevated hepatic glucose output. In concordance with those findings we observed that dioxin treatment caused a strong suppression of the expression of the key hepatic gluconeogenic genes PEPCK and G6Pase. However, this suppression was not solely mediated by the …

Determinación Del Efecto Teratogénico En El Desarrollo Del Tejido Óseo En Rattus Norvegicus Cepa Wistar, Inducido Por La Presencia De Arsénico A Concentraciones Encontradas En Aguas De Zimapán, Hidalgo, México, Mireya Quiterio-Pérez, Juan Carlos Gaytán-Oyarzún, Scott Monks, Alberto José Gordillo-Martínez, Francisco Prieto-García

Estudios científicos en el estado de Hidalgo y zonas aledañas

En el presente trabajo se evaluaron los posibles efectos teratogénicos del Arsénico (As) de las mismas concentraciones registradas en aguas de Zimapán, Hidalgo, empleando ejemplares de Rattus norvegicus de la cepa Wistar, preñadas. Las cuales se sometieron a diferentes concentraciones de Arsenato de Sodio (1887.91 mg/l, 943.95 mg/l y 0.5 mg/l), la concentración 0.5 mg/l corresponde a la registrada en agua de Zimapán, Hidalgo, así como Trióxido de Cromo (166.0 mg/l) utilizado como control positivo y Sacarosa al 5% como un control negativo. Los ejemplares se expusieron del día 7º al 15º de gestación, y se sacrificaron el día 19º …

Combined Effects Of Rearing Environment And Lead (Pb2+) Exposure On Visuospatial Learning And Memory In Rats, Nicholas Tolman

Behavioral Neuroscience Honors Papers

Critical periods of neural development occur during early postnatal life that correspond with increases in synaptic plasticity and the formation of neural circuits needed for learning and memory. This development can be profoundly influenced by experience and negatively affected by environmental toxins. Environmental enrichment and lead exposure inversely affect mediators of synaptic plasticity, which suggests that enrichment may have an attenuating effect on lead induced cognitive deficits. A wealth of evidence has indicated that exposure to excessive amounts of inorganic Pb2+ during early development can produce long lasting cognitive deficits in humans. Evidence also suggests that children raised in an …

Non-Cytotoxic Antibacterial Silver–Coumarin Complex Doped Sol–Gel Coatings, Swarna Jaiswal, Kunal Bhattacharya, Maeve Sullivan, Maureen Walsh, Bernadette Creaven, Fathima Laffir, Brendan Duffy, Patrick Mchale

Articles

Microbial colonisation on clinical and industrial surfaces is currently of global concern and silane based sol–gel coatings are being proposed as potential solutions. Sol–gels are chemically inert, stable and homogeneous and can be designed to act as a reservoir for releasing antimicrobial agents over extended time periods. In the present study, silver nitrate (AgN) and a series of silver coumarin complexes based on coumarin-3-carboxylatosilver (AgC) and it is 6,7 and 8 hydroxylated analogues (Ag6, Ag7, Ag8) were incorporated into sol–gel coatings. The comparative antibacterial activity of the coatings was determined against meticillin resistant Staphylococcus aureus (MRSA) and multidrug resistance Enterobacter …

Function And Regulation Of Intestinal P450 Enzymes : Insights From Conditional Cytochrome P450 Reductase Knockout Mouse Models, Yi Zhu

Legacy Theses & Dissertations (2009 - 2024)

The overall goal of this thesis work was to investigate the function and regulation of intestinal P450 enzymes (P450s). The central hypotheses are that 1) small intestinal (SI) P450s play an important role in the first-pass clearance of oral drugs and in bioactivation of chemicals that cause intestinal toxicity, 2) endogenous regulatory compounds produced by intestinal P450s are important for protection against chemical-induced colon inflammation, and 3) there is a cross talk between the liver and the SI that helps to maintain the overall xenobiotic-metabolism capacity of the digestive tract.

Role Of P450 Enzymes In Tobacco Dependence And Lung Tumorigenesis, Lei Li

Legacy Theses & Dissertations (2009 - 2024)

The overall aim of this study is to better define the roles of P450 enzymes, particularly those in the CYP2A, 2B, and 2F gene subfamilies, in the metabolism and actions of tobacco-related chemicals. Tobacco smoke contains numerous compounds that are deleterious to health, including the primary addictive component nicotine and procarcinogenic compounds, such as naphthalene (NA) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Our main hypotheses are i) that CYP2A and 2B enzymes are largely responsible for nicotine metabolism, and they can impact nicotine dependence; and ii) that CYP2A, 2B, and 2F enzymes play important and tissue-specific roles in NA and NNK bioactivation, leading …

Study Of Charge-Dependent Transport And Toxicity Of Peptide-Functionalized Silver Nanoparticles Using Zebrafish Embryos And Single Nanoparticle Plasmonic Spectroscopy, Kerry J. Lee, Lauren M. Browning, Prakash D. Nallathamby, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Nanomaterials possess unusually high surface area-to-volume ratios and surface-determined physicochemical properties. It is essential to understand their surface-dependent toxicity in order to rationally design biocompatible nanomaterials for a wide variety of applications. In this study, we have functionalized the surfaces of silver nanoparticles (Ag NPs, 11.7 ±+2.7 nm in diameter) with three biocompatible peptides (CALNNK, CALNNS, CALNNE) to prepare positively (Ag-CALNNK NPs^+ζ), negatively (Ag-CALNNS NPs^−2ζ), and more negatively charged NPs (Ag-CALNNE NPs^−4ζ), respectively. Each peptide differs in a single amino acid at its C-terminus, which minimizes the effects of peptide sequences and serves as …

Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Muhammad A. Farooq, Tammy M. Pracheil, Zhejun Dong, Fei Xiao, Zhengchang Liu

Biological Sciences Faculty Publications

Aconitase, the second enzyme of the tricarboxylic acid cycle encoded by ACO1 in the budding yeast Saccharomyces cerevisiae, catalyzes the conversion of citrate to isocitrate. aco1 Delta results in mitochondrial DNA (mtDNA) instability. It has been proposed that Aco1 binds to mtDNA and mediates its maintenance. Here we propose an alternative mechanism to account for mtDNA loss in aco1 Delta mutant cells. We found that aco1 Delta activated the RTG pathway, resulting in increased expression of genes encoding citrate synthase. By deleting RTG1, RTG3, or genes encoding citrate synthase, mtDNA instability was prevented in aco1 Delta mutant …

The Bio-Nano-Interface In Predicting Nanoparticle Fate And Behaviour In Living Organisms: Towards Grouping And Categorising Nanomaterials And Ensuring Nanosafety By Design, Hugh Byrne, Arti Ahluwalia, Diana Boraschi,, Bengt Fadeel, Peter Gehr, Arno C. Gutleb, Michaela Kendall, Manthos Papadopoulos, Iseult Lynch

Articles

In biological media, nanoparticles acquire a coating of biomolecules (proteins, lipids, polysaccharides) from their surroundings, which reduces their surface energy and confers a biological identity to the particles. This adsorbed layer is the interface between the nanomaterial and living systems and therefore plays a significant role in determining the fate and behaviour of the nanoparticles. This review summarises the state of the art in terms of understanding the bio-nano interface and provides direction for potential future research directions and some recommendations for future priorities and strategies to support the safe implementation of nanotechnologies. The central premise is that nanomaterials must …

Does Ecosystem Disturbance Alter The Capacity Of Dissolved Organic Matter To Mitigate The Impact Of Copper To Hyalella Azteca?, Kelly Livingstone

Theses and Dissertations (Comprehensive)

The potential for aquatic ecosystem recovery as a result of dissolved organic matter (DOM) protecting against metal toxicity has become a significant area of research in environmental toxicology. It is a well-characterized relationship that DOM binds free metal ions in a concentration-dependant manner, making them unavailable for toxic action and a reduction in toxicity is seen. Less understood is source variability and how the upland terrestrial environment influences the protective quality of DOM. The aim of this study was to examine the influence of land disturbance (logging, fire, smelter emissions) on DOM quality by comparing the protective capacity of different …

Novel Liquid Chromatography - Fourier Transform Mass Spectrometry (Ms) And Triple Quadrupole Ms Methods For The Determination Of Diarrhetic Shellfish Poisoning (Dsp) Toxins., Bébhine Carey

Theses

Harmful algal blooms (HABs) appear to be on the rise globally, which not only has a negative impact on the shellfish industry but can also cause human and animal intoxications. In order to advance our knowledge of HABs, specific and sensitive analytical methods are required to aid in monitoring shellfish and algal samples for biotoxins, harmful to consumers.

Generation Of Intracellular Reactive Oxygen Species And Genotoxicity Effect To Exposure Of Nanosized Polyamidoamine (Pamam) Dendrimers In Plhc-1 Cells In Vitro, Hugh Byrne, Pratap Naha

Articles

Polyamidoamine (PAMAM) dendrimers elicit systematically variable cyto- and eco-toxic responses, promising the basis for structure activity relationships governing nanotoxicological responses. Increased production of intracellular reactive oxygen species (ROS), genotoxicity and apoptosis due to in-vitro exposure of hepatocellular carcinoma cells to dendrimer generations G-4, G-5 and G-6 is demonstrated. A generation dependent increase in ROS and genotoxicity was observed, consistent with our previous studies. The responses correlate well with the number of surface amino groups per generation. Although ROS production initially increases approximately linearly, it saturates at higher doses. Notably, normalised to molar dose of surface amino groups, the dose-dependent ROS …