[PDF] Use Of Short Term Test Systems For The Prediction Of The Hazard Represented By Potential Chemical Carcinogens eBook

Author :
Publisher :
Page : 129 pages
File Size : 37,50 MB
Release : 1990
Category :
ISBN :

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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.

Author : Larry Ronald Glass
Publisher :
Page : 458 pages
File Size : 19,36 MB
Release : 1987
Category : Carcinogens
ISBN :

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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). The results were statistically significant (p $

Author : K. H. Norpoth
Publisher : Springer
Page : 440 pages
File Size : 45,68 MB
Release : 1980
Category : Medical
ISBN :

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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.

Author : National Research Council
Publisher : National Academies Press
Page : 300 pages
File Size : 38,75 MB
Release : 2007-12-19
Category : Science
ISBN : 0309112982

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The new field of toxicogenomics presents a potentially powerful set of tools to better understand the health effects of exposures to toxicants in the environment. At the request of the National Institute of Environmental Health Sciences, the National Research Council assembled a committee to identify the benefits of toxicogenomics, the challenges to achieving them, and potential approaches to overcoming such challenges. The report concludes that realizing the potential of toxicogenomics to improve public health decisions will require a concerted effort to generate data, make use of existing data, and study data in new waysâ€"an effort requiring funding, interagency coordination, and data management strategies.

Author : V. Chankong
Publisher : Springer Science & Business Media
Page : 214 pages
File Size : 41,9 MB
Release : 2012-12-06
Category : Science
ISBN : 1468455958

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The difficulties associated with making risk assessments on the basis of experimental results are familiar to practitioners in many fields engineering, epidemiology, chemistry, etc. These difficulties are particularly common in problems that have dynamic and stochastic characteristics driven by multiple purposes and goals, with complex interconnections and inter dependencies. Acquiring an appropriate data base, processing and analyzing model results, and transmitting these results at an appropriate technical, social, political, and institutional level are additional difficulties that must be addressed. This book is grounded on the premise that risks are best assessed on the basis of experimental results and sound mathematical analyses, coupled with the knowledge of experts. The carcinogenicity prediction and battery selection (ePBS) approach described herein provides a systematic mechan ism-a synthesis of systems and statistical and decision analyses-to aid researchers and decision makers in the critical field of carcinogenicity prediction in selecting an appropriate battery of tests to use and in translating experimental results into information that can be used as an aid to decision making.

Author : H.C. Grice
Publisher : Springer
Page : 0 pages
File Size : 36,95 MB
Release : 1984-11-01
Category : Medical
ISBN : 9783540136965

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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.