As a result of the industrial revolution, man's technological achievements have been truly great, increasing the quality of life to almost unimagined proportions; but all this progress has not been accomplished without equally un imagined health risks. Sufficiently diagnostic short-term assay procedures have been developed in recent years for us to determine that there are mutagenic agents among thou sands of chemicals to which the human population is exposed today. These chemicals were not significantly present prior to the indus trial revolution. As of today, there are no procedures available which have been adequately demonstrated to assess individual sus ceptibility to genotoxic exposures, and as a result we have had to rely on extrapolating toxicological data from animal model systems. The question is can we afford to allow such an increased environ mental selection pressure via mutagenic exposures to occur without expecting adverse long-term effects on our health. It is apparent from this line of reasoning that what is lacking and immediately needed are test procedures that can be applied to humans to assess genotoxic exposure as well as individual susceptibility to it. There have already been two conferences which have focused at tention on this research area. "Guidelines for studies of human populations exposed to mutagenic and reproductive hazards" (A. D. Bloom, ed., March of Dimes Birth Defects Foundation, White Plains, New York, 1981) and "Indicators of genotoxic exposure in humans" (Banbury Report 13, B. A. Bridges, B. E. Butterworth, and I. B.
In the rapidly developing field of environmental mutagenesis, the use of stand- ardized protocols has permitted the evaluation of large numbers of chemicals for mutagenic and potential carcinogenic activity. In this sixth volume of Chemical Mutagens, the chapters by Perry, Williams, Rosenkranz and Leifer, Kada et al., Pienta, Tazima, Epler, and Rinkus and Legator provide a systematic listing of the chemicals that have been tested, bringing together both unpublished and previously published data. These chapters will serve as an important milestone by providing a convenient reference to tabulated test data with particular assay systems. Another important area of research is the modification of mutagenic activity. In the chapter by Sugimura and Nagao, factors that alter in vitro metabolic activation are discussed, whereas in the chapter by Maher and McCormick, the role of genetic heterogeneity is considered. Equally important is our need to obtain a better understanding of mutation-induction kinetics, and the mathematical analysis by Haynes and Eckardt provides an important step in this direction. An important new approach for the induction of specific locus mutations in human cells in culture is discussed in the chapter by Thilly and co-workers. We have also been concerned about the problems in the practical applica- tion of various short-term tests in commerical testing laboratories. The prob- lems emerging in the evaluation of potentially important new chemicals have been discussed in a chapter by Brusick et al.
Volume 8 of Chemical Mutagens covers a wide range of topics in this continuously changing field. This volume includes chapters on the detection of genetic damage in mammalian sperm both at specific loci and over the entire genome. The discussion of in vitro techniques for working with mammalian cells covers not only specific locus assays but also cellular activation systems. Another chapter extensively discusses the need for a revised protocol for the micronucleus assay. Structure activity relationships are investigated in a chapter dealing with hair dye constituents. One of the most comprehensive chapters deals with problems associated with the detection of mutagenic effects in defined human populations. Finally, there is a detailed presentation of a comprehensive study tabulating the genetic bioassay data on some known or suspected human carcinogens. In keeping with our policy of publishing important legislation in the area of chemical mutagens, we have also included the Council of the European Communities Directive of 18 September 1979. Frederick J. de Serres Research Triangle Park, North Carolina vii Contents Chapter 1 Detection of Effects of Mutagens in Human Populations George R. Hoffmann 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Monitoring Progeny for Evidence of Germ-Cell Mutations. . . . . 3 2. 1. The Classical Approach: Phenotypic Monitoring . . . . . . . 3 2. 2. Monitoring for Changes in Gene Products . . . . . . . . . . . 7 3. Detection of Gene Mutations in Somatic Cells. . . . . . . . . . . . . 9 3. 1. Drug-Resistant Lymphocytes . . . . . . . . . . . . . . . . . . . . . . 9 3. 2. Hemoglobin Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4. Nongenetic Indicators of Mutagen Exposure .. . . . . . . . . . . . 21 4. 1. Alkylation of Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. 2. DNA Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conducting Health Research: Principles, Process, and Methods presents an integrated and practical introduction to the principles and strategies for planning, implementing, reporting, and assessing health sciences research. Comprehensive in its breadth and depth, with an accessible writing style, this text prepares students in public health and related fields to be adept researchers and consumers of health research. Through real-world examples and step-by-step guidance, Frederick J. Kviz provides students with the skills they need to: identify and evaluate research strengths and limitations as practitioners; to actually perform the various core aspects of research; and to choose among alternative methods when making decisions about health practice, policy, and future research needs.
The importance of safety in any scientific endeavor is never in question. However, when cryogenic temperatures are involved, safety is especially important. In addition to observing the normal precautions, one must also take into account the variations of physical properties that occur at low temperatures. At these tempera tures, some properties not only exhibit large differences from their normal values but also can vary widely over a small temperature range. Before any cryogenic project is started, a thorough knowledge of the possible hazards is necessary. Only in this way can the safest operation be attained. Over the hundred-year history of cryogenic research, this has been shown to be the case. Keeping this requirement in mind is an essential ingredient in the quest for accident-free work. The past four or five decades have seen a great expansion of cryogenic technology. Cryogenic liquids, such as oxygen, nitrogen, hydrogen, and helium, have become commonly used in a number of different applications and are easily available in any part of the United States and, indeed, almost anywhere in the world. Not only are these liquids available, they have become less expensive and also available in ever larger quantities. As quantities increase, so also do the conse quences of mishaps. The future seems to hold promise of ever larger and more widespread use of the common cryogens. Thus, the importance of safety also increases as time progresses.