Download or read book OECD Guidelines for the Testing of Chemicals Section 2 Test No 248 Xenopus Eleutheroembryonic Thyroid Assay XETA written by OECD and published by OECD Publishing. This book was released on 2019-06-18 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the test is to measure the capacity of a chemical to activate or inhibit the transcription of a genetic construct (THb/ZIP-GFP X. laevis eleutheroembryos) either by binding to the thyroid hormone receptor or by modifying the amount of thyroid hormone available for transcription. The test is based on the use of a transgenic frog (possessing the genetic construction THb/ZIP-GFP) of the species X. laevis. GFP is a fluorescent protein that can be used to affirm the presence of the substance and to follow its action. This test is based on the quantification of fluorescence, and thus of the GFP protein, throughout the eleutheroembryo exposed to a test chemical. Indeed, if the fluorescence is > 12% by including the highest concentration of the test, the test is considered positive. Organisms are exposed in chemically inert cell culture plates (6 wells). Each well contains ten organisms in solution. In a run, 20 organisms are exposed to each test concentration. Tadpoles are exposed to the test chemical at NF stage 45 for a duration of 72 hours. A positive result of the XETA test indicates in vivo that a substance induces damage to the receptor and metabolization of the thyroid hormone. A negative result indicates that, under test conditions, the test substance does not induce detectable damage to the thyroid and its functioning.

Download or read book The Role of Thyroid Hormones in Vertebrate Development volume II written by Marco António Campinho and published by Frontiers Media SA. This book was released on 2024-04-26 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thyroid hormones role in development was first suggested in the 18th century when a relationship between goiter and cretinism was found by F.E. Fodere. But it was Rudolf Virchow work in the late 19th century with thyroidectomized animals that clearly demonstrated that goiter led to cretinism. This opened the door to the understanding of TH action on vertebrate development. However given the relative ease by which cretinism could be treated simply by eating animal thyroid gland or iodine supplementation, research into the action of TH on vertebrate development has been lagging. This was further enhanced by the complex biology of TH where, after production in the gland, entry, activation and binding of the TH to cognate receptors in target cells is highly regulated. Nonetheless, new scientific advances and technologies are now providing tools to dissect the developmental role of TH on vertebrate development, both embryonic and post-natal. The post-natal role of TH in vertebrate development is long known from anuran studies but less evidences exist from other vertebrates. Recently, new evidences show that TH constitute key developmental signal in embryonic development of vertebrates, especially in neural development, from humans to fish. This new evidences are corroborating long-standing observations that infants from mothers with impaired TH physiology presented changes in mental and cognitive indexes. Nonetheless, given that TH constitute integrative physiological signals in vertebrates a new scenario is emerging whereas TH seem to be important in the development and maturation of most organ systems in vertebrates during their different life transitions

Download or read book Bioanalytical Tools in Water Quality Assessment written by Beate Escher and published by IWA Publishing. This book was released on 2011-12-15 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part of Water Quality Set - Buy all four books and save over 30% on buying separately! Bioanalytical Tools in Water Quality Assessment reviews the application of bioanalytical tools to the assessment of water quality including surveillance monitoring. The types of water included range from wastewater to drinking water, including recycled water, as well as treatment processes and advanced water treatment. Bioanalytical Tools in Water Quality Assessment not only demonstrates applications but also fills in the background knowledge in toxicology/ecotoxicology needed to appreciate these applications. Each chapter summarises fundamental material in a targeted way so that information can be applied to better understand the use of bioanalytical tools in water quality assessment. Bioanalytical tools in Water Quality Assessment can be used by lecturers teaching academic and professional courses and also by risk assessors, regulators, experts, consultants, researchers and managers working in the water sector. It can also be a reference manual for environmental engineers, analytical chemists, and toxicologists. Authors: Beate Escher, National Research Centre for Environmental Toxicology (EnTox), The University of Queensland, Australia, Frederic Leusch, Smart Water Research Facility (G51), Griffith University Gold Coast Campus, Australia. With contributions by Heather Chapman and Anita Poulsen

Download or read book OECD Guidelines for the Testing of Chemicals Section 2 Test No 231 Amphibian Metamorphosis Assay written by OECD and published by OECD Publishing. This book was released on 2009-09-08 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Test Guideline describes an amphibian metamorphosis assay intended to screen substances which may interfere with the normal functioning of the hypothalamo-pituitary-thyroid axis. The assay was validated with the species Xenopus laevis, which is ...

Download or read book Chemical Mixtures and Combined Chemical and Nonchemical Stressors written by Cynthia V. Rider and published by Springer. This book was released on 2018-02-16 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, both basic and advanced concepts are discussed for considering mixtures from initial exposure characterization through evaluation of risk associated with combined exposures. This book will provide an introduction to key issues and multiple options for evaluating both the toxicity of mixtures as well as the risk associated with exposure to mixtures. Additionally, promising tools adapted from other disciplines will be discussed in the context of mixtures toxicology and risk assessment. Finally, the discussion will move beyond chemical mixtures to address incorporating non-chemical stressors into toxicity studies and cumulative risk assessments. Although exposure to multiple chemical and non-chemical stressors is the rule, not the exception, consideration of mixtures in toxicology and risk assessment continues to be a significant challenge. This book will be an essential resource for researchers and professionals in the fields of toxicology, epidemiology, exposure science, risk assessment, and statistics.

Download or read book Clinical Safety and Efficacy Testing of Cosmetics written by William Waggoner and published by CRC Press. This book was released on 1989-11-27 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lattice written by Deepayan Sarkar and published by Springer Science & Business Media. This book was released on 2008-02-15 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the author of the lattice system, this book describes lattice in considerable depth, beginning with the essentials and systematically delving into specific low levels details as necessary. No prior experience with lattice is required to read the book, although basic familiarity with R is assumed. The book contains close to 150 figures produced with lattice. Many of the examples emphasize principles of good graphical design; almost all use real data sets that are publicly available in various R packages. All code and figures in the book are also available online, along with supplementary material covering more advanced topics.

Download or read book Statistical Analysis of Ecotoxicity Studies written by John W. Green and published by John Wiley & Sons. This book was released on 2018-08-14 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to the issues relevant to the design, analysis, and interpretation of toxicity studies that examine chemicals for use in the environment Statistical Analysis of Ecotoxicity Studies offers a guide to the design, analysis, and interpretation of a range of experiments that are used to assess the toxicity of chemicals. While the book highlights ecotoxicity studies, the methods presented are applicable to the broad range of toxicity studies. The text contains myriad datasets (from laboratory and field research) that clearly illustrate the book's topics. The datasets reveal the techniques, pitfalls, and precautions derived from these studies. The text includes information on recently developed methods for the analysis of severity scores and other ordered responses, as well as extensive power studies of competing tests and computer simulation studies of regression models that offer an understanding of the sensitivity (or lack thereof) of various methods and the quality of parameter estimates from regression models. The authors also discuss the regulatory process indicating how test guidelines are developed and review the statistical methodology in current or pending OECD and USEPA ecotoxicity guidelines. This important guide: Offers the information needed for the design and analysis to a wide array of ecotoxicity experiments and to the development of international test guidelines used to assess the toxicity of chemicals Contains a thorough examination of the statistical issues that arise in toxicity studies, especially ecotoxicity Includes an introduction to toxicity experiments and statistical analysis basics Includes programs in R and excel Covers the analysis of continuous and Quantal data, analysis of data as well as Regulatory Issues Presents additional topics (Mesocosm and Microplate experiments, mixtures of chemicals, benchmark dose models, and limit tests) as well as software Written for directors, scientists, regulators, and technicians, Statistical Analysis of Ecotoxicity Studies provides a sound understanding of the technical and practical issues in designing, analyzing, and interpreting toxicity studies to support or challenge chemicals for use in the environment.

Download or read book OECD Guidelines for the Testing of Chemicals Section 2 Test No 243 Lymnaea stagnalis Reproduction Test written by OECD and published by OECD Publishing. This book was released on 2016-07-29 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Test Guideline is designed to assess effects of prolonged exposure to chemicals on the reproduction and survival of the hermaphrodite freshwater snail Lymnaea stagnalis (the Great Pond Snail).

Download or read book Threatened Amphibians of the World written by S. N. Stuart and published by . This book was released on 2008 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Amphibians are facing an extinction crisis, but getting to the facts has been difficult. "Threatened Amphibians of the World" is a visual journey through the first-ever comprehensive assessment of the conservation status of the world's 6,000 known species of frogs, toads, salamanders, and caecilians. All 1,900 species known to be threatened with extinction are covered, including a description of threats to each species and an evaluation of conservation measures in place or needed. Each entry includes a photograph or illustration of the species where available, a distribution map, and detailed information on range, population and habitat and ecology. Introductory chapters present a detailed analysis of the results, complemented by a series of short essays written by many of the world's leading herpetologists. Appendices include annoted lists of lower risk species and a country-by-country listing of threatened amphibians."--pub. desc.

Download or read book Pituitary Adenylate Cyclase Activating Polypeptide PACAP written by Dora Reglodi and published by Springer. This book was released on 2016-10-08 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first comprehensive book to cover all aspects of the last 25 years of PACAP (pituitary adenylate cyclase activating polypeptide) research, this book contains contributions from virtually all the leading researchers in the field, and addresses some of the following topics: evolutionary aspects of PACAP, distribution and occurrence of PACAP and its receptors, hormonal effects of PACAP, intracellular signaling, effects on cellular proliferation and differentiation, protective effects of PACAP, behavioral effects of PACAP, developmental aspects of PACAP, other physiological effects of PACAP (cardiovascular, thermoregulatory), human studies, drug design, metabolism and transport. This compendium can serve as an important reference for researchers and students in PACAP research and can also be a thorough introduction for those in related fields.

Download or read book Animal Care and Use Committees written by John Timothy Allen and published by . This book was released on 1992 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Child to Adult written by Phil A. Silva and published by . This book was released on 1996 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the Dunedin Multidisciplinary Health and Development Study (DMHDS), an ongoing longitudinal study of 1037 babies born in Dunedin between 1 April 1972 and 31 March 1973. The study has generated more than 500 specialist papers in scientific journals, unpublished research reports, theses, etc. This book presents the major findings in a form accessible to the non-specialist.

Download or read book OECD Series on Testing and Assessment Guidance Document on Good In Vitro Method Practices GIVIMP written by OECD and published by OECD Publishing. This book was released on 2018-12-10 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past several decades, there has been a substantial increase in the availability of in vitro test methods for evaluating chemical safety in an international regulatory context. To foster confidence in in vitro alternatives to animal testing, the test methods and conditions under which ...

Download or read book OECD Guidelines for the Testing of Chemicals Section 4 Test No 456 H295R Steroidogenesis Assay written by OECD and published by OECD Publishing. This book was released on 2011-07-28 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Test Guideline describes an in vitro screen for chemical effects on steroidogenesis, specifically the production of 17ß-estradiol (E2) and testosterone (T). The human H295R adreno-carcinoma cell line, used for the assay, expresses genes that ...

Download or read book OECD Guidelines for the Testing of Chemicals Section 4 Test No 441 Hershberger Bioassay in Rats A Short term Screening Assay for Anti Androgenic Properties written by OECD and published by OECD Publishing. This book was released on 2009-09-08 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hershberger Bioassay is an in vivo short–term screening test. It evaluates the ability of a chemical to elicit biological activities consistent with androgen agonists, antagonists or 5 á-reductase inhibitors. The current bioassay is based on the ...

Download or read book OECD Guidelines for the Testing of Chemicals Section 2 Test No 246 Bumblebee Acute Contact Toxicity Test written by OECD and published by OECD Publishing. This book was released on 2017-10-09 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Test Guideline describes a method to assess effects of a test chemical on the phagocytotic activity of activated sludge containing protozoan organisms under defined conditions in the presence of different concentrations of the test chemical. The principle of biological sewage-treatment ...