Nongenotoxic Carcinogenesis
Nongenotoxic Carcinogenesis

Author: A. Cockburn

Publisher: Springer Science & Business Media

Published: 2013-03-14

Total Pages: 279

ISBN-13: 3662030225

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"What is a nongenotoxic carcinogen?" This question recurred through out the Ernst Schering Research Foundation Workshop on nongeno toxic carcinogenesis, underlining the complexity of the topic. The clarity of the view that all carcinogens act by mutating DNA, origin ally advocated by Bruce Ames nearly 20 years ago, has been clouded by the increasing numbers of compounds which are not genotoxic but which nevertheless can cause cancer. There is an urgent need to in crease our understanding of these compounds so that their risks can be evaluated realistically and decisions made from a position of knowl edge and strength, rather than in fear of the unknown. A nongenotoxic carcinogen can be defined as a compound which causes cancer, but which does not cause damage to DNA as its primary biological activity. This negative definition covers a range of carci nogens acting through a variety of mechanisms. Such chemicals often produce tumours only in a single organ species, and there are a few common locations which are affected most often. For example, in male rats, certain carcinogens bind to az globulin to form a complex which 11 accumulates in the kidney tubular cells, which is followed by necrosis and compensatory cell proliferation leading the neoplasia. Other com mon mechanisms include hormonal imbalance resulting in thyroid tu mours or peroxisome proliferation resulting in liver cancer. These and other examples are studied in some detail in the papers of this book.

Carcinogens and Anticarcinogens in the Human Diet
Carcinogens and Anticarcinogens in the Human Diet

Author: National Research Council

Publisher: National Academies Press

Published: 1996-03-12

Total Pages: 434

ISBN-13: 0309053919

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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.

Mechanisms of Carcinogenesis
Mechanisms of Carcinogenesis

Author: Elizabeth K. Weisburger

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 210

ISBN-13: 9400925263

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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.

Issues in Risk Assessment
Issues in Risk Assessment

Author: National Research Council

Publisher: National Academies Press

Published: 1993-02-01

Total Pages: 375

ISBN-13: 0309047862

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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.

Thresholds of Genotoxic Carcinogens
Thresholds of Genotoxic Carcinogens

Author: Takehiko Nohmi

Publisher: Academic Press

Published: 2016-05-20

Total Pages: 226

ISBN-13: 0128018038

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Thresholds of Genotoxic Carcinogens: From Mechanisms to Regulation brings together current opinion and research activities from Japan, the US, and Europe on the subject of genotoxic thresholds. In regulation, it is an adage that genotoxic carcinogens have no thresholds for action, and that they impose cancer risk on humans even at very low levels. This policy is frequently called into question as humans possess a number of defense mechanisms including detoxication, DNA repair, and apoptosis, meaning there is a threshold at which these genotoxic carcinogens take action. The book examines these potential thresholds, describing the potential cancer risks of daily low-level exposure, the mechanisms involved (such as DNA repair, detoxication, translesion DNA synthesis), chemical and statistical methods of analysis, and the ways in which these may be utilized to inform policy. Thresholds of Genotoxic Carcinogens: From Mechanisms to Regulation is an essential reference for any professional researchers in genetic toxicology and those involved in toxicological regulation. - Unites an international team of experts to provide a balanced overview of the current opinion on thresholds of genotoxic carcinogens - Provides all the information readers need to determine a safe threshold for potential genotoxic carcinogens - Includes information on the mechanisms of genotoxic carcinogens and how these can inform regulation - Serves as an essential reference for any professional researchers in genetic toxicology and those involved in toxicological regulation

Chemical Carcinogenesis
Chemical Carcinogenesis

Author: Trevor M. Penning

Publisher: Springer Science & Business Media

Published: 2011-03-03

Total Pages: 447

ISBN-13: 1617379956

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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.

An Introduction to Interdisciplinary Toxicology
An Introduction to Interdisciplinary Toxicology

Author: Carey N. Pope

Publisher: Academic Press

Published: 2020-03-06

Total Pages: 644

ISBN-13: 0128136022

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An Introduction to Interdisciplinary Toxicology: From Molecules to Man integrates the various aspects of toxicology, from "simple” molecular systems, to complex human communities, with expertise from a spectrum of interacting disciplines. Chapters are written by specialists within a given subject, such as a chemical engineer, nutritional scientist, or a microbiologist, so subjects are clearly explained and discussed within the toxicology context. Many chapters are comparative across species so that students in ecotoxicology learn mammalian toxicology and vice versa. Specific citations, further reading, study questions, and other learning features are also included. The book allows students to concurrently learn concepts in both biomedical and environmental toxicology fields, thus better equipping them for the many career opportunities toxicology provides. This book will also be useful to those wishing to reference how disciplines interact within the broad field of toxicology. Covers major topics and newer areas in toxicology, including nanotoxicology, Tox21, epigenetic toxicology, and organ-specific toxicity Includes a variety of perspectives to give a complete understanding of toxicology Written by specialists within each subject area, e.g., a chemical engineer, to ensure concepts are clearly explained