Download or read book Caenorhabditis Elegans as a Model to Study Molecular Mechanisms of Methylmercury Toxicity written by Kirsten Jeanne Helmcke and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury (MeHg), a known neurotoxicant, is found in seafood, leading to regular exposure of humans to this compound. Many of the molecular targets and detoxifying components of MeHg toxicity, including glutathione (GSH), metallothioneins (MTs), and heat shock proteins (HSPs) have been identified; however, the molecular mechanisms of MeHg neurotoxicity are largely unknown. We used the model organism, Caenorhabditis elegans, to elucidate some of these mechanisms. We found that, although MeHg accumulated within C. elegans and caused a delay in development and a decrease in pharyngeal pumping rate, many endpoints, including life span, brood size, thrashing rate, and, most surprisingly, nervous system morphology, were unaffected. This finding led to the hypothesis that C. elegans has unique mechanisms for protecting its nervous system from MeHg neurotoxicity. We examined the involvement of GSH, MTs, and HSPs in MeHg toxicity in C. elegans and found that GSH levels were altered upon MeHg exposure, a glutathione s-transferase was highly upregulated upon exposure, and that the lack of MTs in MT knockout animals resulted in increased sensitivity to this toxicant. We also demonstrated that MeHg can induce hormesis in C. elegans, likely at least partially due to the involvement of GSTs in MeHg toxicity. As a result of our findings, we began to elucidate some of the molecular mechanisms of MeHg neuroprotection in the C. elegans model system. Our findings are highly valuable to the field of human health due to the regular exposure of humans to MeHg.

Download or read book The Nematode Caenorhabditis Elegans written by Jason C. Tew and published by . This book was released on 2008 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification and Characterization of Molecular Modulators of Methylmercury induced Toxicity and Dopamine Neuron Degeneration in Caenorhabditis Elegans written by Natalia M. VanDuyn and published by . This book was released on 2014 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury (MeHg) exposure from occupational, environmental and food sources is a significant threat to public health. MeHg poisonings in adults may result in severe psychological and neurological deficits, and in utero exposures can confer significant damage to the developing brain and impair neurobehavioral and intellectual development. Recent epidemiological and vertebrate studies suggest that MeHg exposure may contribute to dopamine (DA) neuron vulnerability and the propensity to develop Parkinson's disease (PD). I have developed a novel Caenorhabditis elegans (C. elegans) model of MeHg toxicity and have shown that low, chronic exposure confers embryonic defects, developmental delays, reduction in brood size, decreased animal viability and DA neuron degeneration. Toxicant exposure results in an increase in reactive oxygen species (ROS) and the robust induction of several glutathione-S-transferases (GSTs) that are largely dependent on the PD-associated phase II antioxidant transcription factor SKN-1/Nrf2. I have also shown that SKN-1 is expressed in the DA neurons, and a reduction in SKN-1 gene expression increases MeHg-induced animal vulnerability and DA neuron degeneration. Furthermore, I incorporated a novel genome wide reverse genetic screen that identified 92 genes involved in inhibiting MeHg-induced animal death. The putative multidrug resistance protein MRP-7 was identified in the screen. I have shown that this transporter is likely expressed in DA neurons, and reduced gene expression increases cellular Hg accumulation and MeHg-associated DA neurodegeneration. My studies indicate that C. elegans is a useful genetic model to explore the molecular basis of MeHg-associated DA neurodegeneration, and may identify novel therapeutic targets to address this highly relevant health issue.

Download or read book Methylmercury and Neurotoxicity written by Sandra Ceccatelli and published by Springer Science & Business Media. This book was released on 2012-03-23 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury (Hg) is a global pollutant that knows no environmental boundaries. Even the most stringent control of anthropogenic Hg sources will not eliminate exposure given its ubiquitous presence. Exposure to Hg occurs primarily via the food chain due to MeHg’s accumulation in fish. Latest US statistics indicate that 46 States have fish consumption advisories. In addition, Hg is a common pollutant in hazardous waste sites, with an estimated 3-4 million children living within one mile of at least one of the 1,300+ active hazardous waste sites in the US. The effects on intellectual function in children prenatally exposed to MeHg via maternal fish consumption have been the subject of two on-going major, prospective, longitudinal studies in the Seychelles and the Faroe Islands. It is important to recognize that the risk for MeHg exposure is not limited only to islanders with high fish consumption. This book will provide state-of-the-art information to the graduate student training in toxicology, risk assessors, researchers and medical providers at large. It is aimed to bring the reader up to date on contemporary issues associated with exposure to methylmercury, from its effects on stem cells and neurons to population studies.

Download or read book Mitochondrial Dysfunction Caused by Drugs and Environmental Toxicants written by Yvonne Will and published by John Wiley & Sons. This book was released on 2018-03-23 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed as a one-stop reference source for drug safety and toxicology professionals, this book explains why mitochondrial failure is a crucial step in drug toxicity and how it can be avoided. • Covers both basic science and applied technology / methods • Allows readers to understand the basis of mitochondrial function, the preclinical assessments used, and what they reveal about drug effects • Contains both in vitro and in vivo methods for analysis, including practical screening approaches for drug discovery and development • Adds coverage about mitochondrial toxicity underlying organ injury, clinical reports on drug classes, and discussion of environmental toxicants affecting mitochondria

Download or read book Molecular and Cellular Mechanisms of Toxicity written by Lewis L. Smith and published by CRC Press. This book was released on 2019-06-04 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: First Published in 1995: Written by specialists in their fields, this book contains short reviews intended to highlight points of growing interest in mechanistic toxicology. The first section considers selected aspects of molecular mechanisms, including selectivity of toxic agents and repair processes in the nervous system, toxicity of oxygen, fibers and aflatoxins. The second section discusses the interactions of carcinogens with DNA, and other targets, and their relevance to both molecular dosimetry of exposure and development of cancer. The final part is concerned with cellular and genetic aspects and includes coverage of some of the most recent and rapidly developing problems in toxicology.

Download or read book Alternative Methods in Neurotoxicology written by and published by Elsevier. This book was released on 2023-06-08 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alternative Methods in Neurotoxicology, Volume Nine, the latest release in this series, provides an overview of important in vitro and non-vertebrate animal models available to study the neurotoxicity of a range of toxicants of occupational and environmental relevance. Chapters in this new release include Evaluation of mitochondrial function in neurotoxicology using alternative models, Planarians as a model to study neurotoxic agents, Role of Drosophila melanogaster in neurotoxicology studies: Responses to different harmful substances, Neurotoxicology of metals and metallic nanoparticles in Caenorhabditis elegans, Neurotoxicology of environmental toxicants using Caenorhabditis elegans as a model, Nauphoeta cinerea as an emerging model in neurotoxicology, and more. Other chapters cover Human Neural Stem Cells in Developmental Neurotoxicology: Current Scenario and Future Prospects, Use of Drosophila melanogaster for advances in developmental neurotoxicology studies, 3D neurospheres and neurotoxicity of organophosphorus and TCE, Genetic factors in methylmercury-induced neurotoxicity: what we have learned from Caenorhabditis elegans models, and more. Give an up-to-date about the utilization of popular invertebrates (Drosophila melanogaster and Caenorhabditis elegans) in neurotoxicology Brings concise information on emerging invertebrate models in neurotoxicology (from basic to environmental approaches) Presents updates on the in vitro exploitation of human stem cell in developmental neurotoxicology

Download or read book C elegans written by Ian A. Hope and published by OUP Oxford. This book was released on 1999-12-09 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Caenorhabditis Elegans has been a popular model organism for biological research for over thirty years and has been used to investigate many aspects of animal development, for example apoptosis, the Hox genes, signal transduction pathways, and the development of the nervous system. It has recently taken on new importance with the publication of the entire genome sequence in 1998. The first chapter gives all the basic information on C. elegans required to use it: it's natural history, anatomy, life cycle, development, and evolution. Information on how to obtain, grow, and maintain C. elegans for use as a model system is given in Chapter 4. Chapters 2 and 3 describe the genome project and show how to use genome sequence information by searching the database for homologues using different search methods and then how to analyse the search data. The next chapter gives the essential practical details of transformation and common uses for the technique. Chapter 6 covers reverse genetics and describes strategies for gene inactivation that are known to work in C elegans: epigenetic inactivation and mutational germ line inactivation. Chapter 7 is designed to help the user analyse phenotype by microscopy and includes Normaski, fluorescence, 4-dimensional, and electron microscopy. Techniques for studying the neurobiology of C. elegans are given in chapter 8. Chapter 9 describes the three commonly used approaches for studying gene expression and Chapter 10 deals with the common methods of molecular biology essential for gene characterization. C. elegans is not the ideal organism for biochemical studies, but chapter 11 describes several procedures for producing biochemically useful quantities of pure tissues. The final chapter is about conventional genetics and details the standard procedures for selfing and crossing; mutagenesis and mutant screening; characterization of mutants; gene mapping; temperature-shift experiments and mosaic analysis. Caenorhabditis Elegans: A Practical Approach will therefore provide all the background information necessary for use of C. elegans as a model system.

Download or read book Handbook of Developmental Neurotoxicology written by William Slikker Jr. and published by Academic Press. This book was released on 2018-01-04 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Developmental Neurotoxicology, Second Edition, provides a comprehensive view of the fundamental aspects of neurodevelopment, the pathways and agents that affect them, relevant clinical syndromes, and risk assessment procedures for developmental neurotoxicants. The editors and chapter authors are internationally recognized experts whose collaboration heralds a remarkable advance in the field, bridging developmental neuroscience with the principles of neurotoxicology. The book features eight new chapters with newly recruited authors, making it an essential text for students and professionals in toxicology, neurotoxicology, developmental biology, pharmacology, and neuroscience. Presents a comprehensive, up-to-date resource on developmental neurotoxicology with updated chapters from the first edition Contains new chapters that focus on subjects recent to the field Includes well-illustrated material, with diagrams, charts, and tables Contains compelling case studies and chapters written by world experts

Download or read book Scientific Frontiers in Developmental Toxicology and Risk Assessment written by National Research Council and published by National Academies Press. This book was released on 2000-12-21 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific Frontiers in Developmental Toxicology and Risk Assessment reviews advances made during the last 10-15 years in fields such as developmental biology, molecular biology, and genetics. It describes a novel approach for how these advances might be used in combination with existing methodologies to further the understanding of mechanisms of developmental toxicity, to improve the assessment of chemicals for their ability to cause developmental toxicity, and to improve risk assessment for developmental defects. For example, based on the recent advances, even the smallest, simplest laboratory animals such as the fruit fly, roundworm, and zebrafish might be able to serve as developmental toxicological models for human biological systems. Use of such organisms might allow for rapid and inexpensive testing of large numbers of chemicals for their potential to cause developmental toxicity; presently, there are little or no developmental toxicity data available for the majority of natural and manufactured chemicals in use. This new approach to developmental toxicology and risk assessment will require simultaneous research on several fronts by experts from multiple scientific disciplines, including developmental toxicologists, developmental biologists, geneticists, epidemiologists, and biostatisticians.

Download or read book Molecular Epidemiology written by Paul A. Schulte and published by Academic Press. This book was released on 2012-12-02 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will serve as a primer for both laboratory and field scientists who are shaping the emerging field of molecular epidemiology. Molecular epidemiology utilizes the same paradigm as traditional epidemiology but uses biological markers to identify exposure, disease or susceptibility. Schulte and Perera present the epidemiologic methods pertinent to biological markers. The book is also designed to enumerate the considerations necessary for valid field research and provide a resource on the salient and subtle features of biological indicators.

Download or read book Reviews of Environmental Contamination and Toxicology Volume 237 written by W.P. de Voogt and published by Springer. This book was released on 2015-11-27 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews of Environmental Contamination and Toxicology attempts to provide concise, critical reviews of timely advances, philosophy and significant areas of accomplished or needed endeavor in the total field of xenobiotics, in any segment of the environment, as well as toxicological implications.

Download or read book Environmental Epigenetics written by L. Joseph Su and published by Springer. This book was released on 2015-05-18 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the toxicological and health implications of environmental epigenetics and provides knowledge through an interdisciplinary approach. Included in this volume are chapters outlining various environmental risk factors such as phthalates and dietary components, life states such as pregnancy and ageing, hormonal and metabolic considerations and specific disease risks such as cancer cardiovascular diseases and other non-communicable diseases. Environmental Epigenetics imparts integrative knowledge of the science of epigenetics and the issues raised in environmental epidemiology. This book is intended to serve both as a reference compendium on environmental epigenetics for scientists in academia, industry and laboratories and as a textbook for graduate level environmental health courses. Environmental Epigenetics imparts integrative knowledge of the science of epigenetics and the issues raised in environmental epidemiology. This book is intended to serve both as a reference compendium on environmental epigenetics for scientists in academia, industry and laboratories and as a textbook for graduate level environmental health courses.

Download or read book Poisoning in the Modern World written by Ozgur Karcioglu and published by BoD – Books on Demand. This book was released on 2019-06-19 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 400 years ago, Swiss alchemist and physician Paracelsus (1493-1541) cited: "All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy." This is often condensed to: "The dose makes the poison." So, why are we overtly anxious about intoxications?In fact, poisons became a global problem with the industrial revolution. Pesticides, asbestos, occupational chemicals, air pollution, and heavy metal toxicity maintain high priority worldwide, especially in developing countries. Children between 0 and 5 years old are the most vulnerable to both acute and chronic poisonings, while older adults suffer from the chronic effects of chemicals. This book aims to raise awareness about the challenges of poisons, to help clinicians understand current issues in toxicology.

Download or read book Toxicological Effects of Methylmercury written by National Research Council and published by National Academies Press. This book was released on 2000-09-27 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury is widespread in our environment. Methylmercury, one organic form of mercury, can accumulate up the aquatic food chain and lead to high concentrations in predatory fish. When consumed by humans, contaminated fish represent a public health risk. Combustion processes, especially coal-fired power plants, are major sources of mercury contamination in the environment. The U.S. Environmental Protection Agency (EPA) is considering regulating mercury emissions from those plants. Toxicological Effects of Methylmercury reviews the health effects of methylmercury and discusses the estimation of mercury exposure from measured biomarkers, how differences between individuals affect mercury toxicity, and appropriate statistical methods for analysis of the data and thoroughly compares the epidemiological studies available on methylmercury. Included are discussions of current mercury levels on public health and a delineation of the scientific aspects and policy decisions involved in the regulation of mercury. This report is a valuable resource for individuals interested in the public health effects and regulation of mercury. The report also provides an excellent example of the implications of decisions in the risk assessment process for a larger audience.

Download or read book Issues in Pharmacology Pharmacy Drug Research and Drug Innovation 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 4229 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Pharmacology, Pharmacy, Drug Research, and Drug Innovation: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Pharmacology, Pharmacy, Drug Research, and Drug Innovation. The editors have built Issues in Pharmacology, Pharmacy, Drug Research, and Drug Innovation: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Pharmacology, Pharmacy, Drug Research, and Drug Innovation in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Pharmacology, Pharmacy, Drug Research, and Drug Innovation: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book The Changing Faces of Glutathione a Cellular Protagonist written by Alfonso Pompella and published by Frontiers Media SA. This book was released on 2015-07-17 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glutathione (GSH) has been described for a long time just as a defensive reagent against the action of toxic xenobiotics (drugs, pollutants, carcinogens), both directly and as a cofactor for GSH transferases. As a prototype antioxidant, it has been involved in cell protection from the noxious effect of excess oxidant stress, both directly and as a cofactor of glutathione peroxidases. In addition, it has long been known that GSH is capable of forming disulfide bonds with cysteine residues of proteins, and the relevance of this mechanism ("S-glutathionylation") in regulation of protein function has been well documented in a number of research fields. Rather paradoxically, it has also been highlighted that GSH—and notably its catabolites, as originated by metabolism by gamma-glutamyltransferase—can promote oxidative processes, by participating in metal ion-mediated reactions eventually leading to formation of reactive oxygen species and free radicals. Also, a fundamental role of GSH has been recognized in the storage and transport of nitric oxide (NO), in the form of S-nitrosoglutathione (GSNO). The significance of GSH as a major factor in regulation of cell life, proliferation, and death, can be regarded as the integrated result of all these roles, as well as of more which are emerging in diverse fields of biology and pathophysiology. Against this background, modulation of GSH levels and GSH-related enzyme activities represents a fertile field for experimental pharmacology in numerous and diverse perspectives of animal, plant and microbiologic research. This research topic includes 14 articles, i.e. 4 Opinion Articles, 6 Reviews, and 4 Original Research Articles. The contributions by several distinguished research groups, each from his own standpoint of competence and expertise, provide a comprehensive and updated view over the diverse roles, the changing faces of GSH and GSH-related enzymes in cell’s health, disease and death.