Thresholds of Genotoxic Carcinogens

Thresholds of Genotoxic Carcinogens PDF Author: Takehiko Nohmi
Publisher: Academic Press
ISBN: 0128018038
Category : Medical
Languages : en
Pages : 224

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Book Description
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

Thresholds of Genotoxic Carcinogens

Thresholds of Genotoxic Carcinogens PDF Author: Takehiko Nohmi
Publisher: Academic Press
ISBN: 0128018038
Category : Medical
Languages : en
Pages : 224

Get Book

Book Description
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

The Cellular Response to the Genotoxic Insult

The Cellular Response to the Genotoxic Insult PDF Author: Helmut Greim
Publisher: Royal Society of Chemistry
ISBN: 1782626042
Category : Science
Languages : en
Pages : 352

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Book Description
Genotoxic carcinogens can lead to DNA mutations with the potential to cause cancer. Typically, a series of mutation events are needed before malignancy occurs so a single, small exposure may not result in disease. Also, cells have an armoury of defence mechanisms which, to a degree, counter the effects of mutagens. Distinguishing the point at which exposure to a carcinogen increases mutation rates beyond the background level is challenging. In fact, there is now general agreement that, for genotoxic carcinogens, no specific threshold can be identified. However, NOAELs (No Observed Adverse Effect Levels) may be used in the process of establishing a dose-response relationship. These denote the level of exposure at which there is no significant increase in adverse effects in the exposed population when compared to an appropriate control. Such a scientifically defendable threshold allows us to propose health based exposure limits for genotoxic carcinogens. This book describes the various cellular defence mechanisms individually and explains how they are regulated. The processes covered include metabolic inactivation, epigenetic regulation, scavenging mechanisms, DNA-repair and apoptosis. It also considers dose-dependent threshold mechanisms of carcinogenesis and the rate limiting parameters. Aimed at graduate level and above, the book discusses the consequences of genotoxic evaluation and urges readers to question the idea that even low exposures present a cancer risk.

Regulatory Toxicology

Regulatory Toxicology PDF Author: Franz-Xaver Reichl
Publisher: Springer
ISBN: 9783642353734
Category : Medical
Languages : en
Pages : 0

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Book Description
This book will be written by experts for professionals, scientists and all those involved in toxicological data generation and decision-making. It is the updated and expanded version of a monograph published in German in 2004. Chemical safety is regulated on various levels including production, storage, transport, handling, disposal or labelling. This book deals comprehensively with the safety-ensuring methods and concepts employed by regulatory agencies, industry and academics. Toxicologists use experimental and scientific approaches for data collection, e.g. about chemical hazards, physicochemical features or toxicokinetics. The respective experimental methods are described in the book. Toxicologists also deal with much insecurity in the exposure and effect scenarios during risk assessment. To overcome these, they have different extrapolation methods and estimation procedures at their disposal. The book describes these methods in an accessible manner. Differing concepts from one regulation area to another are also covered. Reasons and consequences become evident when reading the book. Altogether, the book Regulatory Toxicology will serve as an excellent reference.

Genotoxic Impurities

Genotoxic Impurities PDF Author: Andrew Teasdale
Publisher: John Wiley & Sons
ISBN: 0470934751
Category : Medical
Languages : en
Pages : 455

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Book Description
This book examines genotoxic impurities and their impact on the pharmaceutical industry. Specific sections examine this from both a toxicological and analytical perspective. Within these sections, the book defines appropriate strategies to both assess and ultimately control genotoxic impurities, thus aiding the reader to develop effective control measures. An opening section covers the development of guidelines and the threshold of toxicological concern (TTC) and is followed by a section on safety aspects, including safety tests in vivo and vitro, and data interpretation. The second section addresses the risk posed by genotoxic impurities from outside sources and from mutagens within DNA. In the final section, the book deals with the quality perspective of genotoxic impurities focused on two critical aspects, the first being the analysis and the second how to practically evaluate the impurities.

Cancer Risk Assessment

Cancer Risk Assessment PDF Author: Ching-Hung Hsu
Publisher: John Wiley & Sons
ISBN: 1118035127
Category : Science
Languages : en
Pages : 727

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Book Description
With a weight-of-the-evidence approach, cancer risk assessment indentifies hazards, determines dose-response relationships, and assesses exposure to characterize the true risk. This book focuses on the quantitative methods for conducting chemical cancer risk assessments for solvents, metals, mixtures, and nanoparticles. It links these to the basic toxicology and biology of cancer, along with the impacts on regulatory guidelines and standards. By providing insightful perspective, Cancer Risk Assessment helps researchers develop a discriminate eye when it comes to interpreting data accurately and separating relevant information from erroneous.

Mutagenic Impurities

Mutagenic Impurities PDF Author: Andrew Teasdale
Publisher: John Wiley & Sons
ISBN: 1119551218
Category : Medical
Languages : en
Pages : 548

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Book Description
Learn to implement effective control measures for mutagenic impurities in pharmaceutical development In Mutagenic Impurities: Strategies for Identification and Control, distinguished chemist Andrew Teasdale delivers a thorough examination of mutagenic impurities and their impact on the pharmaceutical industry. The book incorporates the adoption of the ICH M7 guideline and focuses on mutagenic impurities from both a toxicological and analytical perspective. The editor has created a primary reference for any professional or student studying or working with mutagenic impurities and offers readers a definitive narrative of applicable guidelines and practical, tested solutions. It demonstrates the development of effective control measures, including chapters on the purge tool for risk assessment. The book incorporates a discussion of N-Nitrosamines which was arguably the largest mutagenic impurity issue ever faced by the pharmaceutical industry, resulting in the recall of Zantac and similar drugs resulting from N-Nitrosamine contamination. Readers will also benefit from the inclusion of: A thorough introduction to the development of regulatory guidelines for mutagenic and genotoxic impurities, including a historical perspective on the development of the EMEA guidelines and the ICH M7 guideline An exploration of in silico assessment of mutagenicity, including use of structure activity relationship evaluation as a tool in the evaluation of the genotoxic potential of impurities A discussion of a toxicological perspective on mutagenic impurities, including the assessment of mutagenicity and examining the mutagenic and carcinogenic potential of common synthetic reagents Perfect for chemists, analysts, and regulatory professionals, Mutagenic Impurities: Strategies for Identification and Control will also earn a place in the libraries of toxicologists and clinical safety scientists seeking a one-stop reference on the subject of mutagenic impurity identification and control.

Issues in Risk Assessment

Issues in Risk Assessment PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309047862
Category : Science
Languages : en
Pages : 375

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Book Description
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.

Carcinogens and Anticarcinogens in the Human Diet

Carcinogens and Anticarcinogens in the Human Diet PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309175712
Category : Nature
Languages : en
Pages : 433

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Book Description
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.

Science and Decisions

Science and Decisions PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309120462
Category : Political Science
Languages : en
Pages : 422

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Book Description
Risk assessment has become a dominant public policy tool for making choices, based on limited resources, to protect public health and the environment. It has been instrumental to the mission of the U.S. Environmental Protection Agency (EPA) as well as other federal agencies in evaluating public health concerns, informing regulatory and technological decisions, prioritizing research needs and funding, and in developing approaches for cost-benefit analysis. However, risk assessment is at a crossroads. Despite advances in the field, risk assessment faces a number of significant challenges including lengthy delays in making complex decisions; lack of data leading to significant uncertainty in risk assessments; and many chemicals in the marketplace that have not been evaluated and emerging agents requiring assessment. Science and Decisions makes practical scientific and technical recommendations to address these challenges. This book is a complement to the widely used 1983 National Academies book, Risk Assessment in the Federal Government (also known as the Red Book). The earlier book established a framework for the concepts and conduct of risk assessment that has been adopted by numerous expert committees, regulatory agencies, and public health institutions. The new book embeds these concepts within a broader framework for risk-based decision-making. Together, these are essential references for those working in the regulatory and public health fields.

Genetic Toxicology and Cancer Risk Assessment

Genetic Toxicology and Cancer Risk Assessment PDF Author: Wai Nang Choy
Publisher: CRC Press
ISBN: 0824745221
Category : Medical
Languages : en
Pages : 405

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Book Description
Presents state-of-the-art regulatory cancer risk assessment models including a biologically based model for two-hit carcinogenesis and cell proliferation! This book comprehensively reviews the various roles of genetic toxicology in human cancer risk assessment conducted by United States and worldwide regulatory agencies-discussing hazard identification, dose-response relationships, exposure assessment, and current practices of risk characterization. Examines predictive values of mutagenicity tests, mechanisms of carcinogenesis, and conventional genotoxicity tests required by the International Conference on Harmonization and the Organization for Economic Cooperation and Development/Environmental Protection Agency guidelines! Comprised of contributions from prominent experts and risk assessors and including nearly 1200 references to facilitate further study, Genetic Toxicology and Cancer Risk Assessment reviews contemporary human cancer genetics as related to the mutagenic nature of carcinogenesis calculates acceptable exposure levels based on a carcinogenic threshold dose for nongenotoxic carcinogens reveals the rationale and methodology of quantitative estimation of human cancer risks using mathematical models discusses the threshold concept of carcinogenesis demonstrates how bacterial mutagenicity assays are the most reliable for predicting rodent carcinogens considers structural activity relationship (SAR) analysis of chemical carcinogenicity describes the emergence of the mouse lymphoma microwell and in vitro micronucleus assays illustrates the use of genetic biomarkers for dosimetry analysis and more! Linking human cancer genetics, mutagenicity assays, mechanisms of carcinogenesis, carcinogenic thresholds, molecular epidemiology, mathematical modeling, and quantitative cancer risk analysis, Genetic Toxicology and Cancer Risk Assessment is a must-have reference for toxicologists; oncologists; geneticists; biostatisticians; reproductive, developmental, cell, and molecular biologists; endocrinologists; biochemists; and upper-level undergraduate, graduate, and medical school students in these disciplines.