Toxicology Commons^™

Aluminum And Phthalates In Calcium Gluconate: Contribution From Glass And Plastic Packaging, Robert A. Yokel, Jason M. Unrine

Pharmaceutical Sciences Faculty Publications

Introduction: Aluminum contamination of parenteral nutrition solutions has been documented for three decades. It can result in elevated blood, bone, and whole body aluminum levels associated with neurotoxicity, reduced bone mass and mineral content, and perhaps hepatotoxicity. The primary aluminum source among parenteral nutrition components is glass-packaged calcium gluconate, in which aluminum concentration the past three decades has averaged~ 4000 [mu]g/L, compared to < 200 [mu]g/L in plastic container-packaged calcium gluconate. A concern about plastic packaging is leaching of plasticizers, including phthalates, which have the potential to cause endocrine (male reproductive system) disruption and neurotoxicity.

Methods: Aluminum was quantified in samples collected periodically over more than two years from three calcium gluconate sources used to prepare parenteral nutrition solutions; two packaged in glass (from France and the US) and one in plastic …

Effects Of Chromium On Mouse Splenic T Lymphocytes And Effects Of Ethanol Exposure During Early Neurodevelopment On Behaviors In Mice, Lu Dai

Theses and Dissertations--Toxicology and Cancer Biology

The dissertation consists of three major projects with the focus on the immunotoxicity of chromium and the behavior disorders caused by early ETOH exposure respectively.

Hexavalent chromium [Cr(VI)] is widely used in various industrial processes and has been recognized as a carcinogen. As the first line of host defense system, the immune system can be a primary target of Cr(VI). T cell population represents a major arm of the immune system that plays a critical role in host anti-tumor immunity. Dysfunction of T cells compromises host anti-tumor immunity resulting in oncogenesis. Using mouse splenic T cells as an in vitro …

Comparison Of Protein Phosphatase Inhibition Assay With Lc-Ms/Ms For Diagnosis Of Microcystin Toxicosis In Veterinary Cases, Caroline E. Moore, Jeanette Juan, Yanping Lin, Cynthia L. Gaskill, Birgit Puschner

Veterinary Diagnostic Laboratory Faculty Publications

Microcystins are acute hepatotoxins of increasing global concern in drinking and recreational waters and are a major health risk to humans and animals. Produced by cyanobacteria, microcystins inhibit serine/threonine protein phosphatase 1 (PP1). A cost-effective PP1 assay using p-nitrophenyl phosphate was developed to quickly assess water and rumen content samples. Significant inhibition was determined via a linear model, which compared increasing volumes of sample to the log-transformed ratio of the exposed rate over the control rate of PP1 activity. To test the usefulness of this model in diagnostic case investigations, samples from two veterinary cases were tested. In August …

The Role Of Renal Replacement Therapy In The Management Of Pharmacologic Poisonings, Aibek E. Mirrakhimov, Aram Barbaryan, Adam Gray, Taha Ayach

Internal Medicine Faculty Publications

Pharmacologic toxicities are common and range from mild to life-threatening. The aim of this study is to review and update the data on the role of renal replacement therapy (RRT) in the management of various pharmacologic poisonings. We aim to provide a focused review on the role of RRT in the management of pharmacological toxicities. Relevant publications were searched in MEDLINE with the following search terms alone or in combination: pharmacologic toxicity, hemodialysis, hemofiltration, renal replacement therapy, toxicology, poisonings, critical illness, and intensive care. The studies showed that a pharmacologic substance should meet several prerequisites to be deemed dialyzable. These …

Exploration Of The Srx-Prx Axis As A Small-Molecule Target, Murli Mishra

Theses and Dissertations--Toxicology and Cancer Biology

Lung cancer is a leading cause of cancer-related mortality irrespective of gender. The Sulfiredoxin (Srx) and Peroxiredoxin (Prx) are a group of thiol-based antioxidant proteins that plays an essential role in non-small cell lung cancer. Understanding the molecular characteristics of the Srx-Prx interaction may help design the strategies for future development of therapeutic tools. Based on existing literature and preliminary data from our lab, we hypothesized that the Srx plays a critical role in lung carcinogenesis and targeting the Srx-Prx axis or Srx alone may facilitate future development of targeted therapeutics for prevention and treatment of lung cancer. First, …

Toxicity Of Engineered Nanomaterials To Plant Growth Promoting Rhizobacteria, Ricky W. Lewis

Theses and Dissertations--Plant and Soil Sciences

Engineered nanomaterials (ENMs) have become ubiquitous in consumer products and industrial applications, and consequently the environment. Much of the environmentally released ENMs are expected to enter terrestrial ecosystems via land application of nano-enriched biosolids to agricultural fields. Among the organisms most likely to encounter nano-enriched biosolids are the key soil bacteria known as plant growth promoting rhizobacteria (PGPR). I reviewed what is known concerning the toxicological effects of ENMs to PGPR and observed the need for high-throughput methods to evaluate lethal and sublethal toxic responses of aerobic microbes. I addressed this issue by developing high-throughput microplate assays which allowed me …

The Effects Of Manufactured Nanomaterial Transformations On Bioavailability, Toxicity And Transcriptomic Responses Of Caenorhabditis Elegans, Daniel L. Starnes

Theses and Dissertations--Plant and Soil Sciences

In recent decades, there has been a rapid expansion in the use of manufactured nanoparticles (MNPs). Experimental evidence and material flow models predict that MNPs enter wastewater treatment plants and partition to sewage sludge and majority of that sludge is land applied as biosolids. During wastewater treatment and after land application, MNPs undergo biogeochemical transformations (aging). The primary transformation process for silver MNPs (Ag-MNPs) is sulfidation, while zinc oxide MNPs (ZnO-MNPs) most likely undergo phosphatation and sulfidation. Our overall goal was to assess bioavailability and toxicogenomic impacts of both pristine, defined as-synthesized, and aged Ag- and ZnO-MNPs, as well as …

Role Of Caveolin-1 And Nrf2 In Nutritional Modulation Of Pcb Toxicity, Michael C. Petriello

Theses and Dissertations--Toxicology and Cancer Biology

Cardiovascular disease is the leading cause of mortality in Western societies and is linked to multiple modifiable risk factors including lifestyle choices. Emerging evidence implicates exposure to persistent environmental pollutants, such as polychlorinated biphenyls (PCBs), as a risk factor for the development or progression of cardiovascular disease. To reduce disease risks, it is critical to identify sensible means of biomedically reducing the toxicity of persistent organic pollutants and related environmental stressors.

First, we tested a hypothesis that endothelial cell inflammation and subsequent cardiovascular toxicity initiated by coplanar PCBs is modulated by the crosstalk between caveolae and Nuclear factor (erythroid-derived 2)-like …

The Role Of Surface Chemistry In The Toxicity Of Manufactured Cerium Dioxide Nanomaterials To Caenorhabditis Elegans, Emily Kay Oostveen

Theses and Dissertations--Plant and Soil Sciences

Manufactured CeO₂ nanomaterials (CeO₂-MNMs) are used for a wide variety of applications including diesel fuel additives and chemical/mechanical planarization media. To test the effects of CeO₂-MNM surface coating charge on to model organism Caenorhabditis elegans, we synthesized 4 nm CeO₂ with cationic (DEAE-), anionic (CM-), and neutral (DEX) coatings. In L3 nematodes exposed for 24 hours, DEAE-CeO₂ induced lethality at lower concentrations than CM- or DEX-CeO₂. Feeding slightly decreased CeO₂ toxicity, regardless of coating. In L2 nematodes exposed for 48 hours with feeding, DEAE-CeO₂ caused lethality at the …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

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 …

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 …

Genotoxin-Induced Acetylation Of The Werner Syndrome Protein (Wrn) And Effect On Its Dna Metabolic Function, Enerlyn Meliza Lozada Santiago

University of Kentucky Doctoral Dissertations

Loss of function of the WRN protein causes the genetic disorder Werner Syndrome that is characterized by increased cancer and premature aging. WRN belongs to the RecQ helicase family that plays key roles in preventing genome instability. In response to treatment with genotoxins, WRN is subject to post-translational modification. The relationship of post-translational modification of WRN with its function in DNA metabolism is unknown. There is accumulating evidence suggesting that WRN contributes to the maintenance of genomic integrity through its involvement in DNA replication. Consistent with this notion, WS cells are sensitive to DNA replication inhibitors and DNA damaging agents …

Identification Of Activities Involved In Cag/Ctg Repeat Instability, Nelson Lap Shun Chan

University of Kentucky Doctoral Dissertations

CAG/CTG repeat instability is associated with at least 14 neurological disorders, including Huntington’s disease and Myotonic dystrophy type 1. In vitro and in vivo studies have showed that CAG/CTG repeats form a stable hairpin that is believed to be the intermediate for repeat expansion and contraction.

Addition of extra DNA is essential for repeat expansion, so DNA synthesis is one of the keys for repeat expansion. In vivo studies reveal that 3’ CTG slippage with subsequent hairpin formation (henceforth called the 3’ CTG slippage hairpin) occurs during DNA synthesis. It is proposed that hairpin tolerance machinery is activated because prolonged …

The Influence Of Citrate, Maltolate And Fluoride On The Gastrointestinal Absorption Of Aluminum At A Drinking Water-Relevant Concentration: A 26Al And 14C Study, Yuzhao Zhou, Wesley R. Harris, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

The objectives were to test the null hypotheses that (1) citrate, maltolate, and fluoride do not significantly influence oral Al bioavailability, C_max or T_max at an Al dose relevant to drinking water exposure; and (2) Al citrate and maltolate are absorbed intact from the gastrointestinal tract. Male Fisher rats were given 1 ml of solution intra-gastrically containing 1 nCi ²⁶Al (65 nmol total Al) as the Al³⁺ ion, or as complexes with ¹⁴C-citrate, ¹⁴C-maltolate or fluoride, during concurrent ²⁷Al iv infusion. Blood was repeatedly collected for serum ²⁶Al, total Al and ^{14 …}

The Speciation Of Metals In Mammals Influences Their Toxicokinetics And Toxicodynamics And Therefore Human Health Risk Assessment, Robert A. Yokel, Stephen M. Lasley, David C. Dorman

Pharmaceutical Sciences Faculty Publications

Chemical form (i.e., species) can influence metal toxicokinetics and toxicodynamics and should be considered to improve human health risk assessment. Factors that influence metal speciation (and examples) include: (1) carrier-mediated processes for specific metal species (arsenic, chromium, lead and manganese), (2) valence state (arsenic, chromium, manganese and mercury), (3) particle size (lead and manganese), (4) the nature of metal binding ligands (aluminum, arsenic, chromium, lead, and manganese), (5) whether the metal is an organic versus inorganic species (arsenic, lead, and mercury), and (6) biotransformation of metal species (aluminum, arsenic, chromium, lead, manganese and mercury). The influence of speciation on metal …

Manganese Distribution Across The Blood-Brain Barrier. Iv. Evidence For Brain Influx Through Store-Operated Calcium Channels, Janelle S. Crossgrove, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is a required co-factor for many ubiquitous enzymes; however, chronic Mn overexposure can cause manganism, a parkinsonian-like syndrome. Previous studies showed Mn influx into brain is carrier-mediated, though the putative carrier(s) were not established. Studies conducted with cultured bovine brain microvascular endothelial cells (bBMECs), which comprise the blood–brain barrier, revealed ⁵⁴Mn (II) uptake positively correlated with pH, was temperature-dependent, and was sodium- and energy-independent. Brain ⁵⁴Mn uptake correlated inversely with calcium (Ca) concentration, but ⁴⁵Ca uptake was unaltered by high Mn concentration. Lanthanum (La), a non-selective inhibitor of several Ca channel types, as well as …

Manganese Distribution Across The Blood-Brain Barrier. I. Evidence For Carrier-Mediated Influx Of Managanese Citrate As Well As Manganese And Manganese Transferrin, Janelle S. Crossgrove, David D. Allen, Bonny L. Bukaveckas, Susan S. Rhineheimer, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is an essential element and a neurotoxicant. Regulation of Mn movement across the blood–brain barrier (BBB) contributes to whether the brain Mn concentration is functional or toxic. In plasma, Mn associates with water, small molecular weight ligands and proteins. Mn speciation may influence the kinetics of its movement through the BBB. In the present work, the brain influx rates of ⁵⁴Mn²⁺, ⁵⁴Mn citrate and ⁵⁴Mn transferrin (⁵⁴Mn Tf) were determined using the in situ brain perfusion technique. The influx rates were compared to their predicted diffusion rates, which were determined from …

The Toxicology Of Aluminum In The Brain: A Review, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Aluminum is environmentally ubiquitous, providing human exposure. Usual human exposure is primarily dietary. The potential for significant Al absorption from the nasal cavity and direct distribution into the brain should be further investigated. Decreased renal function increases human risk of Al-induced accumulation and toxicity. Brain Al entry from blood may involve transferrin-receptor mediated endocytosis and a more rapid process transporting small molecular weight Al species. There appears to be Al efflux from the brain, probably as Al citrate. There is prolonged retention of a fraction of Al that enters the brain, suggesting the potential for accumulation with repeated exposure. Al …

Toxicological Studies On Aquatic Contaminants Originating From Coal Production And Utilization: The Induction Of Tolerance To Silver In Laboratory Populations Of Fish And The Chronic Toxicity Of Nickel To Fish Early Life Stages, Wesley J. Birge, Jeffrey A. Black, James F. Hobson, Albert G. Westerman

KWRRI Research Reports

Aquatic toxicity studies were performed on two important coal-derived contaminants, silver and nickel. Silver was investigated with regard to metal-induced tolerance in laboratory populations of the fathead minnow (Pimephales promelas). Fish were exposed to acute silver concentrations following acclimation to sublethal exposures of this metal. Based on median lethal times (LT50), animals which had received 14 days prior exposure to 1.5 and 15 μg Ag/L were three to four times more resistant to silver than were previously unexposed organisms. This metal-induced resistance was not a sustained response. After organisms which had been acclimated to 15 μg/L had been transferred to …

The Induction Of Tolerance To Heavy Metals In Natural And Laboratory Populations Of Fish, Wesley J. Birge, William H. Benson, Jeffrey A. Black

KWRRI Research Reports

Aquatic toxicity studies were performed on two natural populations of fathead minnows. One group of organisms was taken from a metal-contaminated flyash pond associated with a coal-fired power plant and the other group was collected from relatively uncontaminated hatchery ponds. Acute tests indicated that flyash pond fish were significantly more tolerant to cadmium and copper than were hatchery fish. At an exposure concentration of 6.0 mg Cd/L in moderately hard water, the median period of survival for flyash pond fish was 50.0 hr compared to 6.8 hr for hatchery fish. Both groups of organisms were about equally sensitive to zinc. …

Effects Of Organic Compounds On Amphibian Reproduction, Wesley J. Birge, Jeffrey A. Black, Robert A. Kuehne

KWRRI Research Reports

Aquatic toxicity tests were conducted with atrazine, carbon tetrachloride, chloroform, methylene chloride, trisodium nitrilotriacetic acid (NTA), and phenol. Each compound was administered to developmental stages of three to five amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. Test responses included lethality and teratogenesis. Different amphibian species exhibited varying degrees of tolerance to the selected compounds. Greatest tolerance usually was observed for the more broadly adapted semi-aquatic and terrestrial species (e.g., Bufo americanus, Bufo fowleri). The more sensitive amphibians usually included those species which normally are restricted to aquatic or moist habitats (e.g., Rana …