Download or read book Short Term Tests for Chemical Carcinogens written by H.F. Stich and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent surge of interest in designing, validating, and implementing short-term tests for carcinogens has been spurred by the fairly convincing correlation be tween the carcinogenicity and mutagenicity of chemicals and physical agents and by the assumption that DNA alteration, mutations, and chromosome aberrations are somehow involved in neoplastic transformation. Moreover, it has been tacitly assumed that the mutagenic capacity alone of compounds would induce regulatory agencies to pass rules for their removal from the environment and would lead the public to avoid them. The actual response, however, is quite different. Governmental departments shy away from making any decisions on the basis of in vitro test systems. The public at large is becoming irritated by daily an nouncements that many of their cherished habits could adversely affect their health. Industry appears to feel threatened and may reduce its search for new beneficial chemicals. The reluctance to accept wholeheartedly the mutagenicity tests for the detection of carcinogens is partly due to uncertainty about the in volvement of mutations in neoplastic transformation, partly due to the present difficulty of extrapolating results from various endpoints obtained on numerous organisms to man, and partly due to a multitude of complex events that lead in vivo to the evolvement of benign or malignant tumors.
Download or read book Short Term Test Systems for Detecting Carcinogens written by K.H. Norpoth and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: The varying cancer incidence from country to country and region to region suggests that en vironmental factors play a considerable role in the aetiology of cancer. Whether these factors in the environment moderate the effect of car cinogenic chemicals or whether they might them selves be carcinogenic is not known at the present time. What is known is that there are various chemicals, both naturally occurring and man-made, which can induce cancer in man. In the Western world estimates vary as to how much cancer is occupational in origin; the figures range from 1% to 40%. It is our feeling that probably about 10% of cancer has a direct oc cupational origin. Nevertheless this number is considerable and it behoves us therefore to identify those chemicals which are carcinogenic and to reduce human exposure. Recent work on the mode of action of carcinogenic chemicals suggests that the majority exert their effect through an activation step to give elec trophilic metabolites. Such metabolites have as a common feature the ability to react with cel lular nucleophiles to give covalently bound products. Such reaction will occur after carcino gen treatment of animals with nucleic acids par ticularly in target organs. It is reaction with nucleic acids that provides the basis of a num ber of short-term tests for carcinogens, since the basic composition of DNA is similar in micro-organisms and in human cells.
Download or read book Carcinogens and Anticarcinogens in the Human Diet written by National Research Council and published by National Academies Press. This book was released on 1996-02-12 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite increasing knowledge of human nutrition, the dietary contribution to cancer remains a troubling question. Carcinogens and Anticarcinogens assembles the best available information on the magnitude of potential cancer riskâ€"and potential anticarcinogenic effectâ€"from naturally occurring chemicals compared with risk from synthetic chemical constituents. The committee draws important conclusions about diet and cancer, including the carcinogenic role of excess calories and fat, the anticarcinogenic benefit of fiber and other substances, and the impact of food additive regulation. The book offers recommendations for epidemiological and diet research. Carcinogens and Anticarcinogens provides a readable overview of issues and addresses critical questions: Does diet contribute to an appreciable proportion of human cancer? Are there significant interactions between carcinogens and anticarcinogens in the diet? The volume discusses the mechanisms of carcinogenic and anticarcinogenic properties and considers whether techniques used to evaluate the carcinogenic potential of synthetics can be used with naturally occurring chemicals. The committee provides criteria for prioritizing the vast number of substances that need to be tested. Carcinogens and Anticarcinogens clarifies the issues and sets the direction for further investigations into diet and cancer. This volume will be of interest to anyone involved in food and health issues: policymakers, regulators, researchers, nutrition professionals, and health advocates.
Download or read book Interpretation and Extrapolation of Chemical and Biological Carcinogenicity Data to Establish Human Safety Standards written by H.C. Grice and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Life Sciences Institute (lLSI) is a scientific foundation wh ich addresses critical health and safety issues of national and international concern. ILSI promotes international cooperation by pro viding the mechanism for scientists from government, industry and universities to work together on cooperative programs to generate and disseminate scientific data. The members and trustees of the Institute believe that questions regarding health and safety are best resolved when scientists can ex amine and discuss issues, as an independent body, se~arate from the political pressures of individual countries and the economic concerns of individual companies. Frequently, meaningful assessment of the risk of a test substance is hindered by the inherent inconsistencies in the system. The development and refinement of methods and systems to evaluate the safety of chemicals have evolved in a rapid and largely unplanned fashion. Attempts to improve the system have largely been directed toward broad general concerns, with little attention being given to specific problems or issues. A failure to resolve these problems has frequently resulted in increased testing costs and complications in the assessment and extrapolation of the results. Publicity surrounding toxicologic issues has created chronic public apprehension about the ability of science and government to deal effectively with these problems. In response to these difficulties, ILSI has assembled highly qualified and renowned scientists from research institutes, universities, government and industry, with relevant scientific knowledge and expertise regarding the issues that complicate risk assessment procedures.
Download or read book Short Term Tests for Chemical Carcinogens written by British Columbia Cancer Research Centre. Environmental Carcinogenesis Unit and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Carcinogenesis written by Trevor M. Penning and published by Springer Science & Business Media. This book was released on 2011-03-03 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume will provide a contemporary account of advances in chemical carcinogenesis. It will promote the view that it is chemical alteration of the DNA that is a route cause of many cancers. The multi-stage model of chemical carcinogenesis, exposure to major classes of human carcinogens and their mode-of-action will be a focal point. The balance between metabolic activation to form biological reactive intermediates and their detoxification, ensuing DNA-lesions and their repair will be profiled. It will describe the chemical changes that occur in DNA that result from endogenous insults including epigenetic changes that lead to gene silencing. It will describe major mechanisms of mutagenesis, affects on tumor suppressor genes and proto-oncogenes, and how cell-cycle check points can be by-passed by the "stealth-like" properties of chemical carcinogens. Environmental agents that can promote tumor formation will be discussed. The monograph will have wide appeal as a knowledge base for graduate students, post-doctoral fellows and faculty interested in this aspect of cancer causation and research.
Download or read book The Predictive Value of Short term Screening Tests in Carcinogenicity Evaluation written by and published by Elsevier-North-Holland Biomedical Press. This book was released on 1980 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Efficacy of Short term Tests for Certain Classes of Chemical Carcinogens written by Vincent R. Nathan and published by . This book was released on 1983 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strategies for Short term Testing for Mutagens carcinogens written by Byron E. Butterworth and published by . This book was released on 1979 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidelines for the Testing of Chemicals for Carcinogenicity written by Great Britain. Committee on Carcinogenicity of Chemicals in Food, Consumer Products, and the Environment and published by . This book was released on 1982 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report of the NTP Ad Hoc Panel on Chemical Carcinogenisis sic Testing and Evaluation written by National Toxicology Program (U.S.). NTP Ad Hoc Panel on Chemical Carcinogenesis Testing and Evaluation and published by . This book was released on 1984 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanisms of Carcinogenesis written by Elizabeth K. Weisburger and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: but also the possibility of intervention in specific stages. In Human behavior, including stress and other factors, plays an important role in neoplasia, although too little is known addition, variables which affect cancer development as well on the reasons for such development. Carcinogens, which as some endogenous factors can be better delineated help initiate the neoplastic process, may be either synthetic through such investigations. The topics of this volume encompass premalignant non or naturally-occurring. Cancer causation may be ascribed to invasive lesions, species-specific aspects of carcinogenicity, certain chemicals, physical agents, radioactive materials, viruses, parasites, the genetic make-up of the organism, and radiation, viruses, a quantum theory of carinogenesis, onco bacteria. Humans, eumetazoan animals and vascular plants genes, and selected environmental carcinogens. are susceptible to the first six groups of cancer causes, whe reas the last group, bacteria, seems to affect only vascular plants. Neoplastic development may begin with impairment ofJmdy defenses by a toxic material (carcinogen) which acts as an initiator, followed by promotion and progression to an overt neoplastic state. Investigation of these processes Series Editor Volume Editor allows not only a better insight into the mechanism of action Hans E. Kaiser Elizabeth K. Weisburger vii ACKNOWLEDGEMENT Inspiration and encouragement for this wide ranging project on cancer distribution and dissemination from a comparative biological and clinical point of view, was given by my late friend E. H. Krokowski.
Download or read book Review of Short term Screening Tests for Mutagens Toxigens and Carcinogens written by Heath J. Carney and published by . This book was released on 1979 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Short term Test Systems for the Prediction of the Hazard Represented by Potential Chemical Carcinogens written by and published by . This book was released on 1990 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address the problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs.
Download or read book Issues in Risk Assessment written by National Research Council and published by National Academies Press. This book was released on 1993-02-01 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scientific basis, inference assumptions, regulatory uses, and research needs in risk assessment are considered in this two-part volume. The first part, Use of Maximum Tolerated Dose in Animal Bioassays for Carcinogenicity, focuses on whether the maximum tolerated dose should continue to be used in carcinogenesis bioassays. The committee considers several options for modifying current bioassay procedures. The second part, Two-Stage Models of Carcinogenesis, stems from efforts to identify improved means of cancer risk assessment that have resulted in the development of a mathematical dose-response model based on a paradigm for the biologic phenomena thought to be associated with carcinogenesis.
Download or read book Short term Tests for Carcinogens Mutagens and Other Genotoxic Agents written by Anne Trontell and published by . This book was released on 1979 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Short term Tests for Carcinogens written by Frederick J. De Serres and published by North-Holland. This book was released on 1981 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
