Basic Life Sciences - Böcker

1. In the lumbar spinal canal of the achondroplast there is decreased cross-sectional area. In addition the intervertebral foramina are narrow. These changes result in reduced area for the dural sac and exiting spinal nerves. 2. There is associated thoracolumbar kyphosis and a lumbosacral hyperlordosis. These sagittal plane changes result in increased tension on the dural sac and nerves. 3. With aging there is disc degeneration with disc space narrowing and osteophyte formation. In addition facet hypertrophy with osteophyte formation are common. These degenerative changes further reduce the size of an already compromised spinal canal and intervertebral foramina. The above understanding of the normal spinal and anatomy in the achondroplast, and the added effects of aging allow the surgeon to plan a logical treatment regimen for neurological problems in the achondroplast. Fig. 6. Cross-section at the di sc level of an achondroplast (A) and an age matched non-achondroplast (B). The cross-sectional area of the spinal canal is reduced in the achondroplast, with a reduction in the antero- posterior canal (C vs. C 1 ).There is facet hyper- trophy extending into the nerve root canal and into the spinal canal lateral recess (B vs. B 1 ). In ad- dition the nerve root canal is markedly reduced in-the achondroplast (D vs. D1 ). (Reprinted with permis- sion, as of Fig. 5). 225 REFERENCES 1. R. J. Eulert, Scoliosis and kyphosis in dwarfing conditions, Arch. Orthop.Traum. Surg.102:45 (1983).

This symposium is the third in a series featuring the propaga­ tion of higher plants through tissue culture. One of the aims of these symposia was to examine the current state­ of-the-art in tissue culture technology and to relate this state of technology to practical, applied, and commercial interests.

It is delightful but humbling to find my face at the start of these Proceedings--there are innumerable other faces which could equally weIl stand there, from among the band who have fore­ gathered at every gerontology conference since the subject was launched in its present form; but I deeply appreciate being there. Gerontology d. id not grow by accident. Its present standing is the fruit of careful planning, undertaken by European and American scientists back in the 1950's. In those days it was still a "fringe" science, and the conspirators had much the standing of the 1920's Interplanetary Society. The United States itself is the offspring of conspiracy, for when the results of conspiracy are beneficent, the conspirators become Founding Fathers. This has been the case with gerontology. The present meeting is especially gratifying because the papers have been recitals of normal, hard-science investigation. We had to get through the rigors of a long period of semantic argument and a long period of one-shot general theories before this kind of meeting, normal in all other research fields, could take place. It was also necesssary to breed in the menagerie a generation of excellent investigators aware of the theoretical background but unintimidated by it, who share our conviction that human aging is comprehensible and probably controllable, and who go into the laboratory to attack specifics.

This Volume contains the papers presented by twenty-eight invited speakers at the symposium entitled, "Genetic Manipulation of Woody Plants," held at Michigan State University, East Lansing, Michigan, from June 21-25, 1987. Also included are abstracts of contributed poster papers presented during the meeting. That the molecular biology of woody plants is a rapidly expanding field is attested to by the large attendance and high level of enthusiasm generated at the conference. Leading scientists from throughout the world discussed challenging problems and presented new insights into the devel­ opment of in vitro culture systems, techniques for DNA analysis and manipulation, gene vector systems, and experimental systems that will lead to a clearer understanding of gene expression and regulation for woody plant species. The presence at the conference of both invited speakers and other scientists who work with nonwoody plant species also added depth to the discussions and applicability of the information presented at the conference. The editors want to commend the speakers for their well-organized and informative talks, and feel particularly indebted to the late Dr. Alexander Hollaender and others on the planning committee who assist­ ed in the selection of the invited speakers. The committee consisted of David Burger (University of California, Davis), Don J. Durzan (University of California, Davis) , Bruce Haissig (U. S. Department of Agriculture Forest Service), Stanley Krugman (U. S. Department of Agriculture Forest Service) , Ralph Mott (North Carolina State University), Otto Schwarz (Univer.sity of Tennessee, Knoxville), and Roger Timmis (Weyerhaeuser Company).

Gilbert S. Omenn Dean, School of Public Health and Community Medicine University of Washington Seattle, Washington 98195 On behalf of the University of Washington , the City of Seattle, the Steering Committee, and the sponsoring agencies, corporations, and organ­ izations, I welcome you. \Ve all expect this Conference to stimulate further what is becoming an important application of biotechnology in an area in which our society experiences considerable frustration and gloom: the management of hazardous wastes. It is an all-too-frequent refrain that technology has its benefits and its risks. To many--in the lay pUblic, at least--the damaging notion has taken hold that we are capable of creating problems but are less capable of finding solutions. Chemical streams from industry, agriculture, municipal operations, and household operations have contaminated groundwater, drinking water, and soils, and have undermined the productivity of agri­ culture and the quality of life. In the meantime, however, we have im­ proved our quality of life in immeasurable ways through some related developments. The challenge is to continue the enhancements while modifying or preventing the damage.

This book is the compilation of papers presented at the International Symposium on in vivo Body Composition Studies, held at the University of Toronto, Ontario, Canada, June 20 - 23, 1989. The purpose of this conference was to report on advances in techniques for the in vivo measurement of body composition and to present recent data on normal body composition and changes during disease. This conference was the most recent of several meetings on body composition studies, and follows two successful such meetings, one at Brookhaven National Laboratory in 1986, and at Edinburgh in 1988. The large number of excellent research papers and posters presented at these conferences demonstrates the rapid growth of the field and the broad interest in the subject of in vivo body composition studies. The proceedings of the Brookhaven meeting "In Vivo Body Composition Studies", is published by The Institute of Physical Sciences in Medicine, London. Both the Brookhaven and the current Toronto meeting emphasized the clinical applications, together with the techniques employed. The Edinburgh meeting placed more emphasis on the methodological problems and design of instrumentation. Because of the number of papers presented at the meeting it was necessary to ask the authors from the same institution to combine their presentations into a single paper where appropriate. The editors wish to thank the authors for their cooperation and for graciously accepting the minor revisions made to each manuscript.

This book was developed from the proceedings of the 2nd North American Tan­ nin Conference held in Houghton, Michigan, June, 1991. The objective of this con­ ference was to bring together people with a common interest in plant polyphenols and to promote interdisciplinary interactions that will lead to a bet ter understand­ ing of the importance of these substances. Another objective of this conference was to extend the 'tannin family' by making special efforts to encourage participation by scientists outside the United States, obtain more coverage of the hydrolyzable tannins, and further broaden the scope of coverage from the initial concentration on forestry and forest products. Com­ parison of the contents of this book with 'Chemistry and Significance of Condensed Tannins' that resulted from the proceedings of the 1st North American Tannin Conference shows the degree that these objectives were met. In developing the second conference, care was taken to assure that this book extends rather than duplicates the coverage of the first conference. Therefore, the two books should be taken together to obtain an up to date coverage of the broad area of chemistry and significance of plant polyphenols. Our thanks go to the authors who so kindly contributed chapters and so pa­ tiently responded to our requests. We thank the Conference Assistance Staff of Michigan Technological University for their help in planning and conducting the conference.

This book is the compilation of papers presented at the International Symposium on In Vivo Body Composition Studies, held in Houston, Texas, November 10-12, 1992. The purpose of this conference was to report on the state-of-the-art techniques for in vivo body composition measurements and to present the most recent human data on normal body composition and changes during disease. This conference was the third in a series of meetings on body composition studies held in North America, and follows the successful meetings at Brookhaven National Laboratory in 1986, and the one in Toronto in 1989. A large number of excellent research papers were offered for consideration at this Conference which demonstrates the rapid growth of the field in the last three years. However, we had to limit the presentations to approximately 90 papers which provided a broad spectrum of the applications and recent interest in the subject. The proceedings of the Brookhaven meeting "In Vivo Body Composition Studies", is published by The Institute of Physical Sciences in Medicine, London. The proceedings of the Toronto meeting "In Vivo Body Composition Studies" was published by Plenum Press in its basic life science series. Both these meetings placed more emphasis on technical aspects while the current Houston meeting tried to emphasize more the emerging clinical applications of these techniques. The general sessions used at the Conference for presentations forms the basis of the order of appearance of the papers in this book.

Charles E. Hess Department of Environmental Horticulture University of California Davis, CA 95616 Research in the biology of adventitious root formation has a special place in science. It provides an excellent forum in which to pursue fundamental research on the regulation of plant growth and development. At the same time the results of the research have been quickly applied by commercial plant propagators, agronomists, foresters and horticulturists (see the chapter by Kovar and Kuchenbuch, by Ritchie, and by Davies and coworkers in this volume). In an era when there is great interest in speeding technology transfer, the experiences gained in research in adventitious root formation may provide useful examples for other areas of science. Interaction between the fundamental and the applied have been and continue to be facilitated by the establishment, in 1951, of the Plant Propagators' Society, which has evolved into the International Plant Propagators' Society, with active programs in six regions around the world. It is a unique organization which brings together researchers in universities, botanical gardens and arboreta, and commercial plant propagators. In this synergistic environment new knowledge is rapidly transferred and new ideas for fundamental research evolve from the presentations and discussions by experienced plant propagators. In the past 50 years, based on research related to the biology of adventitious root formation, advances in plant propagation have been made on two major fronts.

The Office of Health and Environmental Research (OHER) has supported and continues to support development of computational approaches in biology and medicine. OHER's Radiological and Chemical Physics Program initiated development of computational approaches to determine the effects produced by radiation of different quality (such as high energy electrons, protons, helium and other heavy ions, etc. ) in a variety of materials of biological interest-such as water, polymers and DNA; these include molecular excitations and sub-excitations and the production of ionization and their spatial and temporal distribution. In the past several years, significant advances have been made in computational methods for this purpose. In particular, codes based on Monte Carlo techniques have ·been developed that provide a realistic description of track-structure produced by charged particles. In addition, the codes have become sufficiently sophisticated so that it is now possible to calculate the spatial and temporal distribution of energy deposition patterns in small volumes of subnanometer and nanometer dimensions. These dimensions or resolution levels are relevant for our understanding of mechanisms at the molecular level by which radiations affect biological systems. Since the Monte Carlo track structure codes for use in radiation chemistry and radiation biology are still in the developmental stage, a number of investigators have been exploring different strategies for improving these codes.

This compendium presents some of the major applications of neutron scattering techniques to problems in biology. It is a record of the papers presented at the Neutrons in Biology Conference, the third in an occasional series held to highlight progress in the field and to provide a focus for future direction. The strength ofthe neutron scattering technique remains principally in the manipula­ tion of scattering density through hydrogen and deuterium atoms. The development ofad­ vanced detectors, innovative instrument and beamline components, and sophisticated data acquisition systems through the 1970s and early 1980s provided a sound foundation for the technique. With continued development, some of the exotic and expensive equipment has become affordable by the medium-sized facilities, thereby broadening the user base considerably. Despite problems with the major neutron sources in the late 1980s and early 1990s, some spectacular results have been achieved. Whilst the high and medium flux beam reac­ tors will continue to make a major impact in the field, the results from the first experi­ ments, and the planned developments on spallation neutron sources, clearly indicate that the technique has enormous potential.

We also would like to thank the Bend Chamber of Commerce, Central Oregon Community College, The Riverhouse, Interstate Tours, Wanderlust Tours, and the people of Bend for welcoming our group to Central Oregon.

Physical and chemical agents in the environment damage the DNA of humans, and pose a major threat to human health today, and to the genetic integrity of human populations. Although studies on isolated DNA in vitro, on prokaryotes, on mammalian cells in culture, and on laboratory animals have provided essential background information, it is now possible to study DNA damage and repair in human tissues directly. New techniques of high sensitivity, especially those not requiring radioactive labeling have made possible quantitation of DNA damage and repair, as well as detection of residual, unrepaired DNA lesions . In recent years, several investigators have taken up the challenge of studying damage and repair responses in humans, and we have chosen that work as the special focus of this Symposium. Major advances in under­ standing damage and responses in human skin, in blood cells and in human internal organs indicate three major themes. First, DNA damage levels in human tissues depend not only on the initial exposures, but also on the capapacity of that tissue for repair of the specific lesion type. Second, repair in human tissues may differ quantitatively and qualitatively from that in human cells in culture.

This book is the compilation of papers presented at the International Symposium on in vivo Body Composition Studies, held at the University of Toronto, Ontario, Canada, June 20 - 23, 1989. The purpose of this conference was to report on advances in techniques for the in vivo measurement of body composition and to present recent data on normal body composition and changes during disease. This conference was the most recent of several meetings on body composition studies, and follows two successful such meetings, one at Brookhaven National Laboratory in 1986, and at Edinburgh in 1988. The large number of excellent research papers and posters presented at these conferences demonstrates the rapid growth of the field and the broad interest in the subject of in vivo body composition studies. The proceedings of the Brookhaven meeting "In Vivo Body Composition Studies", is published by The Institute of Physical Sciences in Medicine, London. Both the Brookhaven and the current Toronto meeting emphasized the clinical applications, together with the techniques employed. The Edinburgh meeting placed more emphasis on the methodological problems and design of instrumentation. Because of the number of papers presented at the meeting it was necessary to ask the authors from the same institution to combine their presentations into a single paper where appropriate. The editors wish to thank the authors for their cooperation and for graciously accepting the minor revisions made to each manuscript.

This Volume contains the papers presented by twenty-eight invited speakers at the symposium entitled, "Genetic Manipulation of Woody Plants," held at Michigan State University, East Lansing, Michigan, from June 21-25, 1987. Also included are abstracts of contributed poster papers presented during the meeting. That the molecular biology of woody plants is a rapidly expanding field is attested to by the large attendance and high level of enthusiasm generated at the conference. Leading scientists from throughout the world discussed challenging problems and presented new insights into the devel­ opment of in vitro culture systems, techniques for DNA analysis and manipulation, gene vector systems, and experimental systems that will lead to a clearer understanding of gene expression and regulation for woody plant species. The presence at the conference of both invited speakers and other scientists who work with nonwoody plant species also added depth to the discussions and applicability of the information presented at the conference. The editors want to commend the speakers for their well-organized and informative talks, and feel particularly indebted to the late Dr. Alexander Hollaender and others on the planning committee who assist­ ed in the selection of the invited speakers. The committee consisted of David Burger (University of California, Davis), Don J. Durzan (University of California, Davis) , Bruce Haissig (U. S. Department of Agriculture Forest Service), Stanley Krugman (U. S. Department of Agriculture Forest Service) , Ralph Mott (North Carolina State University), Otto Schwarz (Univer.sity of Tennessee, Knoxville), and Roger Timmis (Weyerhaeuser Company).

The analysis of intra-group correlations between LS and BW at representative intervals yields no consistent support for the hypothesis that lower BW is associated with longer LS. Indeed, among male Wistar rats and C57BL/6J and A/J mice followed since weaning on AL diets, the data suggested that relatively higher BW across the adult LS was generally associated with longer life. Even when the diet was restricted by EOD or RES regimens, this pattern of positive correlations between LS and BW persisted for the C57BL/6J and A/J strains when relative ages were analyzed. However, when BW at absolute ages were correlated with LS, support for the positive relationship between BW and LS was not as forthcoming. When AL groups were assessed beginning at later ages (> 10 months), the pattern of positive correlations was very evident for the Wistar rats--heavier rats tended to liver longer. This pattern was also evident among AL-fed C57BL/6J mice followed since 6 months, but was lost in the 10-month group in this strain. Among A/J mice on AL diets, the pattern became somewhat negative when followed at 6 and 10 months of age. However, among both C57BL/6J and A/J mice placed on EOD diets at 6 and 10 months of age, the pattern clearly tended toward the positive.

The "Symposium on Aneuploidy: Etiology and Mechanisms" was held at the Carnegie Institution of Washington Auditorium from March 25-29. 1985. This Symposium developed as a consequence of the concern of the Environmen­ tal Protection Agency with the support of the National Institute of Envi­ ronmental Health Sciences about human exposure to environmental agents that cause aneuploidy. The program was chosen to explore what is currently known about the underlying causes, the origins, and the extent of the prob­ lem of human aneuploidy, and whether exposure to environmental agents is assodated with an increased incidence of aneuploidy in humans. Basic research findings in the area of mitosis and meiosis were presented and related to possible mechanisms of how aneuploidy may be produced spontane­ ously and chemically. A survey of data regarding the chemical induction of aneuploidy in experimental organisms was presented. Outstanding scientists from different fields were invited to cover a broad perspective of aneu­ ploidy from the molecular aspects to the human situation. We hope that the publication of the proceedings will share the enthu­ siasm of the meeting and its scientific content. The topic of aneuploidy has received little attention and it is the purpose of this Volume to establish a scientific basis for assessing health risks posed by environ­ mental exposures to aneuploidy-inducing chemicals. Vicki L. DeJlarco Peter E. Voytek Alexander Hollaender vii ACKNOWLEDGEMENT The Editors of the proceedings of the "Symposium on Aneuploidy" wish to acknowledge the support of Dr. Elizabeth L.

The study of bacterial plasmids has not always been as popular as it is today. For many years, the molecular biology of pro cary- otes was focused heavily on bacteriophage and plasmid investigations which were carried out in only a few laboratories. Whatever inter- est existed in plasmids concerned the role of these extrachromosomal elements in bacterial conjugation, genetic exchanges, and antibiotic resistance, as well as in the structure of plasmids themselves. Gradually, however, it became increasingly evident that many of the special characteristics displayed by bacteria of medical, agricul- tural, industrial, and environmental importance are determined by genes carried by plasmids, and this interest in plasmid-encoded functions, such as bacterial virulence properties (exotoxin produc- tion, serum resistance, adhesiveness), metabolism of organic com- pounds, plant tumor formation, and biological nitrogen fixation, led to increasing study of. the plasmids that carry these genes.Inves- tigations of other plasmid-related properties such as replication and recombination have yielded much information about fundamental biological processes; information having implications that extend far beyond the particular plasmids under study. Concurrently, plas- mids were playing a key role in the discovery of bacterial transpos- able elements and were proving to be increasingly useful in the elu- cidation of mechanisms responsible for a variety of chromosomal rearrangement events in bacteria and plants. Their status as "mini- chromosomes" that could be isolated easily from bacterial cells and then reintroduced into other cells by transformation is of fundamen- tal importance in this regard.

This book is concerned with the genetic consequences of nu­ cleotide pool imbalance. There are a number of ways in which this state can be achieved and the majority of papers in this volume de­ scribe the effects of nucleotide pool imbalance on DNA replication and repair, and the induction of gene mutations in various organisms. This book grew out of a Conference on "Genetic Consequences of Nu­ cleotide Pool Imbalance" which was held at the National Institute of Environmental Health Sciences on May 9-11, 1983. The Organizing Com­ mittee consisted of Drs. Diana Anderson (BIBRA), Robert Haynes (York University), Bernard Kunz (NIEHS), Barry Glickman (NIEHS), and Frederick J. de Serres (NIEHS), Chairman. The meeting was org- ized by the staff of the Office of the Associate Director for Genetics and was financed solely by the National Institute of Environmental Health Sciences. Frederick J. de Serres, Ph.D. Associate Director for Genetics v CONTENTS SECTION I. INTRODUCTION Molecular Mechanisms in Genetic Stability and Change: 1 The Role of Deoxyribonucleotide Pool Balance •••••• Robert H. Haynes SECTION II. NUCLEOTIDE METABOLISM 25 Metabolic Effects of Poly(ADP-ribose) Inhibitors •••••••• Kathryn M. Milam and James E. Cleaver Ribonucleotide Reductase and Deoxyribonucleotide 33 POQ 1 s ............................................ . Peter Reichard 47 Enzymatic Channeling of DNA Precursors •••••••••••••••••• Christopher K. Mathews A Possible Secondary Role for Thymine-Containing DNA 67 Precursors ....................................... . Robert J. Melamede and Susan S. Wallace Multiple Mechanisms of Adenosine Toxicity in an Adenosine Sensitive Mutant of Baby Hamster 103 Kidney (BHK) Cells............................... .

This book was inspired by an intimate, stimulating, intellectually enrich­ ing conference that took place in Poland. However, the book is not a conference report. Rather, at the time of the conference, participants agreed that it would be worthwhile to create a volume representing the international state of knowledge in pro social behavior, and many of them agreed to write chapters. This volume is the outcome. The book contains chapters by outstanding researchers and scholars who have made substantial contributions to some aspect of scholarship about pro social behavior-helpfulness, generosity, kindness, coopera­ tion, or other behavior that benefits people. The book concerns itself with how prosocial behavior comes about and what influences contrib­ ute to or inhibit it; how prosocial behavior, or values and other personal characteristics that promote prosocial behavior, develop; how socializa­ tion, peer interaction, and other experiences contribute to development; and with the cognitive, emotional, and behavioral consequences of re­ ceiving help. Some chapters directly, and a number of them implicitly, concern themselves with applications of knowledge about prosocial be­ havior, particularly with the question of how cooperation and behavior that benefits other people can be promoted. The purpose of the book is. in part to show where the field stands and what knowledge we have accumulated, and in part to suggest fu­ ture directions and advance the field. It is a truly international book, with contributors from most countries where research on pro social be­ havior is being conducted.

Polyploidy as a dramatic mutational event in the process of evolution has wide implications in nature and for the generation of new and improved crops. The three day Conference on POLYPLOIDY: BIOLOGICAL RELEVANCE focused on three aspects of this natural phenomenon: the first emphasized the characteristics of polyploidy, the second described the occurrence of polyploidy among plants and animals, and the third considered past and future areas of both fundamental and pragmatic research that involve polyploidy. New information relative to origin, cytogenetics, ecology, physiology, biochemistry, and populational studies stress the need to reexamine current views on the origins of polyploidy and its significance among both plants and animals. There are major differences in the occurrence of polyploidy between. plant groups and it is proving a much more common event among bisexual vertebrates than heretofore considered possible. Crop development and improvement must utilize approaches based fundamentally on more natural systems; in fact future research should focus more on polyploidy as a natural phenomenon that needs study at all levels of endeavor from field-oriented populational aspects to sophisticated molecular analyses and genome manipulations. This volume provides a summary of current knowledge of polyploidy pertinent to botanists, zoologists, and agriculturists who are interested in the evolution o~natural systems and who are concerned with the contribution that crop improvement can make to human well-being. Walter H. Lewis St. Louis, Missouri October, 1979 v ACKNOWLEDGMENTS The Host Committee thanks all speakers and moderators for their generous contribution to the Conference and to this volume.

In writing this book, I found the choice of a suitable title to be a most vexing problem. Lehninger's excellent earlier monograph The Mitochondrion had already appropriated in the domain of library cards what appeared to be the most fitting description of the subject matter. Once the text was completed, however, it became obvious that pluralization was the simplest solution to this dilemma. Variations in the structure and function of this organelle and recent discoveries of the phylogenetic diversity in the organization and genetic con­ tent of its DNA all seemed to justify the idea that there are as many different mitochondria as there are mitochondriologists. Even though my initial intention was to provide advanced undergraduate and graduate students of cell biology with supplemental reading material on topics usually dealt with in a cursory manner by most standard texts, inevitably the scope was broadened to attract the interest of more seasoned readers who might be familiar with some but not other areas of mitochondrial studies. Con­ sistent with the original aim, literature citations have been kept to a minimum and are avoided in the main body of the text for purposes of readability.

It has been nearly 35 years since the peacetime Biology Division of Oak Ridge National Laboratory was started, born of rather inauspicious conditions. Virtually no facilities were available and most of the wartime scientists had left. So, when we started out, it was obvious to me that something had to be done to reestab­ lish research. Even more, because Oak Ridge was not known at that time for its biological work but rather for the separation of Uranium 235, nuclear reactor development, and radioisotope produc­ tion, a new tradition had to be promoted. Although good biological work had been done at Oak Ridge during the war to protect the workers and the results of this work were quite excellent, very few installations remained. When we started the work of the Biology Division, it became essential to make it part of the flow of mod~rn biology allover the world. As Director, I had to do more than just attract promising scientists. We created an atmosphere conducive to creative research and nurtured all of the other aspects of a productive laboratory. Of course, we carefully prepared the results of our work in publish­ able form. We made a sincere effort to invite seminar speakers and lecturers to come to Oak Ridge despite the sacrifices this presented to our early budget. We also had to do something more, and here I "cashed in" on my experience of the previous 15 years.

In numerous conversations with our colleagues from India, it was suggested that we help to institute a series of symposia in India similar in nature to those that have been conducted by our Latin American colleagues for more than 10 years. We were fortunate to have with us in Oak Ridge Dr. Niyogi and Dr. Mitra from Indian universities. Their close ties with the Bose Institute in Calcutta and the resultant correspondence with the Institute Director, Dr. S. M. Sircar, provided the stimulus for organization of this first Indian symposium, which was held in Calcutta. Under the direction of Dr. Sircar, Dr. B. B. Biswas did an outstandingjob of organizing this conference. Financial support was arranged through Dr. R. R. Ronkin of the United States National Science Foundation, who smoothed the way for the use of PL 480 funds which were approved by the Indian Government for the organization and running of this most valuable symposium. The many Indian scientists who contributed papers and enthusiastically and vigorously entered into the discussions demonstrated the strength of modern science in India. The topic, Control of Transcription, is a timely one, and considerable activity in this area is going on all over the world. The success of this symposium speaks well for the future of these Indian conferences and workshops being planned for the next few years. Again, the worldwide "community of science" is clearly manifested by the close cooperation we have observed in this fruitful and successful symposium.

Lifestyle, in any part of the world, is associated with the occurrence of major chronic diseases, including coronary heart disease, hypertension, and stroke; many distinct types of cancer; and adult onset diabetes (11,22,70,75). One important element of lifestyle is tobacco use, which appreciably increases the risk of a number of chronic diseases (21). Other lifestyle factors relate to nutritional traditions, alcohol use, and exercise (11,30,58,60,70,71). The underlying evidence is, in part, based on the evidence of specific diseases in relation to dietary habits in a given geographic region, as well as changes in such disease occurrences in migrant populations from a low risk to a high risk area, and vice versa (25,42). Populations that customarily consume fruits and vegetables and also whole grain cereal products generally have a lower risk of cardiovascular diseases and specific types of cancer than populations with a lower intake of such foods, everything else being equal (63). In the last few years, research has provided mechanistic explanations as to the reasons for the protective effects of specific foods. This paper will emphasize the mechanisms whereby cancer risks are reduced by dietary modification.

This book was developed from the proceedings of the 2nd North American Tan­ nin Conference held in Houghton, Michigan, June, 1991. The objective of this con­ ference was to bring together people with a common interest in plant polyphenols and to promote interdisciplinary interactions that will lead to a bet ter understand­ ing of the importance of these substances. Another objective of this conference was to extend the 'tannin family' by making special efforts to encourage participation by scientists outside the United States, obtain more coverage of the hydrolyzable tannins, and further broaden the scope of coverage from the initial concentration on forestry and forest products. Com­ parison of the contents of this book with 'Chemistry and Significance of Condensed Tannins' that resulted from the proceedings of the 1st North American Tannin Conference shows the degree that these objectives were met. In developing the second conference, care was taken to assure that this book extends rather than duplicates the coverage of the first conference. Therefore, the two books should be taken together to obtain an up to date coverage of the broad area of chemistry and significance of plant polyphenols. Our thanks go to the authors who so kindly contributed chapters and so pa­ tiently responded to our requests. We thank the Conference Assistance Staff of Michigan Technological University for their help in planning and conducting the conference.