This fifth volume in the series The Plant Viruses, dealing with viruses with bipartite genomes, completes the coverage of viruses with isometric parti cles and genomes consisting of single-stranded, positive-sense RNA: viruses that have tripartite and monopartite genomes of this kind were dealt with in Volumes 1 and 3, respectively. How close are the affinities among the viruses within the groupings distinguished in this way? All those with tripartite genomes are considered to be sufficiently closely related to be included in the family Bromoviridae, whereas the monopartite-genome viruses covered in Volume 3 clearly are a much more diverse collection. Affinities among the viruses with bipartite genomes are considered in Chapter 1 of this volume, along with the possible origins, advantages, and disadvantages of these ge nomes. The conclusion reached from this assessment is that the bipartite genome viruses fall into four categories, those within each category having closer affinities with viruses not included in this book than with viruses in the other categories. No evidence was found that possession of a bipartite genome gives a virus overwhelming advantages over viruses of other sorts. More probably, any advantages are largely balanced by disadvantages, and bipartite genomes may be best considered simply as an alternative design for the hereditary material of a virus.

It is now just 20 years since Gomatos and his co-workers at the Rocke feller University showed that the nucleic acid in reovirus particles is double-stranded RNA (dsRNA). This discovery created great excitement, for dsRNA was at that time under intense investigation as the replicative form of viral genomes consisting of single-stranded RNA. An equally interesting and important finding followed soon after: it was found that the reovirus genome consists, not of a single nucleic acid molecule, but of 10 discrete "segments," each with its specific sequence content and each transcribed into its own messenger RNA. It is clear now that these segments are genes. Not surprisingly, the availability of a viral genome 10 unlinked genes has permitted some unique lines of in consisting of vestigation in molecular biology. Mammalian and avian reoviruses proved to be but the first of several viruses recognized as sharing Similarity in size and morphology and ge nomes consisting of 10, II, or 12 separate genes. These viruses are dis tributed throughout living organisms; among the natural hosts of mem bers of this virus family are vertebrates, Insects, and plants. Members of the Reoviridae family differ widely in the virulence that they exhibit toward their hosts . . For example, the first discovered mam malian reovirus literally is, as the name signifies, a "respiratory enteric orphan" virus, that is, a virus unassociated with disease."

Over the last few years, bacterial adhesion has become a more and more important and active scientific area, but the field lacks communication and scientific exchange between medical and microbiology researchers who work with the relevant biological systems, and biochemists, structural biologists and physicists, who know and understand the physical methods best suited to investigate the phenomenon at the molecular level. The field consequently would benefit from a cross-disciplinary conference enabling such communication. This book tries to bridge the gap between the disciplines.

Vector transmission of pathogens affecting human, animal, and plant health continues to plague mankind both in industrialized and Third World coun tries. The diseases caused by these pathogens cost billions of dollars an nually in medical expenses and lost productivity. Some cause widespread of food-and fiber-producing plants and animals, whereas others destruction present direct and immediate threats to human life and further development in Third World countries. During the past 15 years or so, we have witnessed an explosive increase in interest in how vectors acquire, carry, and subsequently inoculate dis ease agents to human, animal, and plant hosts. This interest transcends the boundaries of anyone discipline and involves researchers from such varied fields as human and veterinary medicine, entomology, plant pa thology, virology, physiology, microbiology, parasitology, biochemistry, molecular biology, genetic engineering, ultrastructure, biophysics, bio systematics, biogeography, ecology, behavioral sciences, and others. Ac companying and perhaps generating this renewed interest is the realization that fundamental knowledge of pathogen-vector-host interrelationships is a first and necessary step in our quest for efficient, safe methods of disease control."

No other area of biology has grown as fast and become as relevant over the last decade as virology. It is with no little amount of amaze ment, that the more we learn about fundamental biological questions and mechanisms of diseases, the more obvious it becomes that viruses perme ate all facets of our lives. While on one hand viruses are known to cause acute and chronic, mild and fatal, focal and generalized diseases, on the other hand, they are used as tools for gaining an understanding of the structure and function of higher organisms, and as vehicles for carrying protective or curative therapies. The wide scope of approaches to different biological and medical virological questions was well rep resented by the speakers that participated in this year's Symposium. While the epidemic by the human immunodeficiency virus type 1 continues to spread without hope for much relief in sight, intriguing questions and answers in the area of diagnostics, clinical manifestations and therapeutical approaches to viral infections are unveiled daily. Let us hope, that with the increasing awareness by our society of the role played by viruses, not only as causative agents of diseases, but also as models for better understanding basic biological principles, more efforts and resources are placed into their study. Luis M. de la Maza Irvine, California Ellena M."

Thousands of different microbial species colonize the human body, and are essential for our survival. This book presents a review of the current understanding of human microbiomes, the functions that they bring to the host, how we can model them, their role in health and disease and the methods used to explore them. Current research into areas such as the long-term effect of antibiotics makes this a subject of considerable interest. This title is essential reading for researchers and students of microbiology.

depth overview of the retrovirus family. I have greatly enjoyed and learned from this experience. Each chapter is an excellent introduction to the topic covered and provides a good foundation for further work in the field. Jay A. Levy University of California School of Medicine San Francisco, California REFERENCES Brown, E. W., Yuhki, N., Packer, C., and O'Brien, S. J., 1994, A lion lentivirus related to feline immunodeficiency virus: Epidemiologic and phylogenetic aspects, ,. Viral. 68:5953-5968. Merza, M., Larsson, E., Steen, M., and Morein, B., 1994, Association of a retrovirus with a wasting condition in the Swedish moose, Virology 202:956-961. Contents Chapter 1 The Human Immunodeficiency Viruses Edward Barker, Susan W Barnett, Leonidas Stamatatos, and Jay A. Levy I. Introduction .................................................... 1 TI. Description of Agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 A. Virus Structure .............................................. 2 B. Genetic Organization and Gene Function ...................... 2 TIL Transmission.................................................... 7 A. General Observations ........................................ 7 B. HIV Transmission by Blood and Blood Products ................ 8 C. HIV Transmission by Genital Fluids ........................... 10 D. HIV Transmission by Other Body Fluids ....................... 12 E. Mother-to-Child Transmission ................................ 12 IV. HIV Infection of the Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 . . . . . . . . . . . . . A. Introduction ................................................. 13 B. HIV-Cell Interaction............ ............... .............. 15 C. CD4-Induced gp120 Conformational Changes .................. 16 D. Soluble CD4-Induced gp120-gp41 Dissociation..... ............ 16 E. gp120 Proteolytic Cleavage ................................... 17 F. pH-Independent Membrane Fusion ............................ 19 G. Transmission of HIV by Cell-to-Cell Fusion.................... 19 H. Additional Cell Surface Receptors for HIV ..................... 20 I. The Envelope Region and Cell Tropism ........ . . . . . . . . . . . . 21 . . . .

This book is a compilation of the research which was presented during the NATO-Advanced Research Workshop (ARW) entitled "Advances in Bacterial Paracrystalline Surface Layers" held in London, Ontario, Canada during September 27 to 30, 1992. The organizing committee consisted of the two Workshop directors, S. F. Kaval and T. J. Beveridge, and H. Konig, U. B. Sleytr and T. J. Trust; their summary statements about the significance and success of the NATO-ARWare in Chapter 37 of this book. This was the third international workshop on bacterial S-layers and it demonstrated unequivocally how rapidly research is progressing. The Workshop was made possible by financial support from the North Atlantic Treaty Organization (NATO), the Medical Research Council of Canada (MRC), the Natural Seiences and Engineering Research Council of Canada (NSERC), and the Canadian Bacterial Diseases Network (CBDN) which is a Canadian National Centre of Excellence (NCE). We are very grateful for the support from all of these agencies since their financial aid made it possible to bring to London, Canada a truly international group of S-layer experts. We encouraged the attendance and participation of graduate fellows and research associates, and their presentations students, postdoctoral was an intense three constitute the "Poster" section of this book. The NATO-ARW day workshop held at a delightful secluded location (Spencer Hall) so that the delegates had both formal and informal occasions to interact and evolve new ideas."

Although there are a number of excellent current reviews on one or another aspect of cytomegalovirus, the last comprehensive treatment of this subject was that of Krech et al. (197la). In view of the amazing advances in the virological, epidemiologic, and clinical knowledge of cytomegaloviruses, an up-to-date book is needed. Such a work should cover many areas of expertise and a voluminous technical literature. Each area might have been reviewed and analyzed by workers more expert than myself. However, I have embarked on the entire venture alone in order to attain unity and continuity in this book, characteristics that are not easily achieved in the more popular multiauthored works. I have tried to review the Iiterature and provide a critical summary for each area discussed. To do this, I provide as much of the primary data of the relevant works as needed and not just the qualitative conclusions. Inevitably, the flow of the narrative may be interrupted by dry facts and figures. However, such information is essential to make this a meaningful reference work. But for those not interested in such details, I have provided at what I hope are crucial points critiques and summaries. This book is not an exhaustive review of all the literature. This is probably no Ionger possible or even desirable. By selection, however, one runs the risk of having missed or ignored important papers. I am keenly aware of this, and I wish to apologize for such oversight, if that is possible.

The world needs clean and renewable energy and hydrogen represents an almost ideal resource. Hydrogen is the simplest and most abundant molecule in the universe, yet one that is a challenge to produce from renewable resources. Biohydrogen, or hydrogen produced from renewable resources such as water or organic wastes by biological means, is a goal worthy of increased global attention and resources. The purpose of BioHydrogen '97 was to bring together leaders in the biological p- duction of hydrogen from the United States, Japan, Europe, and elsewhere to exchange scientific and technical information and catalyze further cooperative programs. Parti- pants came from at least different countries representing academia, industry, and g- ernment. Especially important participants were young research scientists and engineers: the next generation of contributors. The conference consisted of plenary presentations, topical sessions, posters, and mini-workshop discussions on key areas of biohydrogen. It was designed to maximize - formation exchange, personal interaction among participants, and formulate new inter- tional initiatives. BioHydrogen '97 was an outgrowth of an international workshop convened by the Research Institute of Innovative Technology for the Earth (RITE) and was held in Tokyo, Japan, November 24-25, 1994. The RITE workshop was highly successful but largely l- ited to traditional biochemical and biological studies and not engineering research topics.

The papers contained in this book were presented at a NATO Advanced Research Workshop (ARW) held at Cape Sounion, Athens, Greece, 19-24 May, 1991. The twenty-eight more comprehensive papers represent the key subjects of the ARW covered by invited speakers. The thirty-four short papers pre sented in a research format are contributions of those invited to participate in the ARW. There was a total of 70 participants from 21 countries. The objectives of the ARW were as follows: to review current knowledge of biological control of plant diseases and plant parasitic nematodes, with emphasis on mechanisms at the molecular, cellular, organismal, and ecosystem level; to examine and expand on current concepts and synthesize new concepts; to identify and prioritize limitations in the use of biological control for plant diseases and nematodes and the scientific research needed to overcome these limitations; and to develop strategies for biological control through management of resident agents or introduction of natural or modified agents."

The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having passed only recently through its descriptive phase of naming and num bering, has probably reached that stage at which relatively few new-truly new-viruses will be discovered. Triggered by the intellectual probes and techniques of molecular biology, genetics, bio chemical cytology, and high resolution microscopy and spec troscopy, the field has experienced a genuine information explosion. Few serious attempts have been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of about 18 volumes, represents a commitment by a large group of active investigators to analyze, digest, and expostulate on the great mass of data relating to viruses, much of which is now amorphous and disjointed, and scattered throughout a wide literature. In this way, we hope to place the entire field in perspective, and to develop an invalua ble reference and sourcebook for researchers and students at all levels. This series is designed as a continuum that can be entered anywhere, but which also provides a logical progression of developing facts and integrated concepts.

In this translation of the Italian second edition, the authors provide a comprehensive account of the current knowledge on antibiotics. They concisely describe how various scientific disciplines are involved in antibiotics research, development, and use. Their work also discusses the industrial and clinical development of new antibiotics, as well as the questions and controversies related to the function of antibiotics in nature. Antibiotics is richly illustrated with clear chemical structures, drawings, diagrams, and synoptical tables.

This treatise is focused on early aspects of fungal pathogenesis in plant and animal hosts. Our aim in choosing the topics and contributors was to demonstrate common approaches to studies of fungal-plant and fungal-animal interactions, particularly at the biochemical and molecular Ievels. For example, the initial events of adh"sion of fungal spores to the exposed surface tissues of the host are essential for subsequent invasion of the plant or animal and establishment of pathogenesis. A point of consensus among investigators who have directed their attention to such events in plants, insects, and vertebrates isthat spore adhesion to the host cuticle or epithelium is more than a simple binding event. lt is a complex and potentially pivotal process in fungal-plant interactions which "may involve the secretion of ftuids that prepare the infection court for the development of morphological stages of the germling" and subsequent invasion of the host (Nicholson and Epstein, Chapter 1). The attachment of the fungal propagule to the arthropod cuticle is also "mediated by the chemical components present on the outer layer of the spore wall and the epicuticle . . . . Initial attachment may be reinforced further by either the active secretion of adhesive materials or the modification of spore wall materiallocated at the [fungal spore arthropod] cuticle interface (Boucias and Pendland, Chapter 5).

Biotechnology is a word that was originally coined to describe the new processes which could be derived from our ability to manipulate, in vitro, the genetic material common to all organisms. I t has now become a generic term encompassing all "applications" of living systems, including the more traditional fermentation and agricultural industries. Recombinant DNA technology has opened up new opportunities for the exploitation of microorganisms and animal and plant cells as producers or modifiers of chemical and biological products. This series of handbooks deals exclusively with microorganisms which are at the forefront of the new technologies and brings together in each of its volumes the background information necessary to appreciate the historical development of the organisms making up a particular genus, the degree to which molecular biology has opened up new opportunities, and the place they occupy in today's biotechnology industry. Our aim was to make this primarily a practical approach, with emphasis on methodology, combining for the first time information which has largely been spread across a wide literature base or only touched upon briefly in review articles. Each handbook should provide the reader with a source text, from which the importance of the genus to his or her work can be identified, and a practical guide to the handling and exploitation of the organisms included.

The literature in microbial ecology is growing rapidly. Journals in many countries dealing with microbiology, ecology, environmental sciences, and environmental technology are publishing an ever-increasing number of papers, and these reports are providing microbial ecologists with a wealth of information. This body of data is now so large and the research is published in so many journals and mono graphs that maintaining an overview of the development of the field grows more difficult. The role of Advances in Microbial Ecology thus becomes more obvious with time. The articles in the present volume encompass an array of topics appropriate to the development of the discipline of microbial ecology. Both terrestrial and aquatic ecosystems are subjects of attention, and a variety of microbiological groups come under review. Furthermore, methodological problems and ap proaches are not overlooked. The ecology of protozoa, constraints on their populations, and their role in nutrient cycling and energy flow are considered by J. D. Stout. A unique micro environment is discussed by B. Norkrans, the surface microlayer of aquatic eco systems, and Dr. Norkrans presents information on a field that has blossomed in the last few years. The subject of the review by H. S. Lowendorf is the genus Rhizobium, a group of bacteria whose importance has grown as the cost of fuel for production of nitrogen fertilizers and ultimately for protein production has increased.

In this volume we aim to present an easy-to-read account of the genus Saccharomyces that we hope will be of value to all students and researchers wishing to exploit this important genus, be it for academic or commer cial purposes. Individual chapters have been commissioned to cover specific aspects of the biology of Saccharomyces species: growth, genetics, and metabolism, with the emphasis on methodology. Basic principles are discussed without an over-detailed, step-by-step breakdown of specific techniques, and lengthy discussions of standard molecular, biological, and biochemical techniques (e. g., polyacrylamide gel electrophoresis, protein purification, DNA sequencing) have been avoided. We hope the volume will provide a quick reference to the current status of a wide range of Saccharomyces-specific methodologies without focusing ex clusively on recent developments in molecular techniques which can be found in the ever increasing numbers of "cloning manuals. " By necessity, much of what is described in this volume concentrates on one particular species of Saccharomyces, namely Saccharomyces cerevisiae. This is not just a reflection of the authors' interests, but indicates the extent to which this simple eukaryote has been studied by biologists from all walks of life, for all sorts of reasons. If this volume can provide a broader knowledge base to the experienced yeast researcher, or ease the path of someone just starting work with Saccharomyces, then we will have achieved our aim."

Hepatitis A virus (HAV) is responsible for around half of the total number of hepatitis infections diagnosed worldwide. HAV infection is mainly propagated via the fecal-oral route, and as a consequence of globalization, transnational outbreaks of foodborne infections are reported with increasing frequency. Therefore, in this review, state-of-the-art information on the molecular procedures for HAV detection in food, and the efficacy of common food manufacturing processes are compiled. The purpose of this Brief is to consolidate basic information on various aspects of HAV and to provide a guideline for its prevention and control across the food supply chain from pre-harvest to manufacturing. "

This SpringerBrief will a comprehensive account of the functions and effects of the Epstein-Barr virus (EBV) EBNA1 protein that relate to EBV-associated cancers and evidence for EBNA1 contributions to these cancers. EBNA1 was the first EBV protein detected and the most critical for EBV latent infection. EBNA1 fulfills multiple functions at EBV genomes which have been described in many (sometimes confusing) reports over the last 28 years. While these were initially thought to be the only roles of EBNA1, many reports in recent years have shown that EBNA1 also directly affects cellular processes in ways that would be expected to contribute to oncogenesis. However, the degree to which EBNA1 promotes cell survival and oncogenesis in various types of human tumours is not entirely clear and a matter of debate. This Brief would offer a current synopsis of EBNA1 functions in EBV latency, including functions in DNA replication, mitotic segregation and transcription. Mechanisms of these EBNA1 functions will also be discussed as well as implications for tumourigenesis. In addition, the many cellular effects of EBNA1 will be reviewed, including how EBNA1 manipulates specific cellular proteins and relationships to EBV-associated lymphomas and carcinomas.

Joseph E. Alouf "The empirical basis of objective science has thus nothing 'abso lute' about it. Science does not rest upon solid bedrock. The bold structure of its theories rises, as it were, above swamp. It is like a building erected on piles. The piles are driven down from above into the swamp, but not down to any natural or 'given' base; and if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being. " -Karl Popper (The Logic of Scientific Discovery) hen I was invited to write this introductory chapter I was hon W ored and pleased to have the opportunity to briefly highlight some important issues relevant to structural aspects of bacterial protein tox ins. The present book attempts for the first time to provide into one volume a series of chapters prepared by invited experts on the struc ture of these fascinating macromolecules. A particular emphasis is placed on the molecular features of these highly active biomolecules in rela tion to their biological properties and mechanisms of action. The researchers in bacterial protein toxinology of my generation have had the privilege of witnessing over 40 years the tremen dous development of this field of biological sciences, particularly in the past decade.

Familiarity with nitric oxide is essential to a modern understanding of pathophysiologic mechanisms of infectious disease. Recent research has established nitric oxide and related reactive nitrogen intermediates to be important molecular mediators of diverse physiologic processes such as control of vascular tone, regulation of the immune system, and microbial and tumor cell growth. This book contains chapters by the leading researchers in the field and examines the biology and biochemistry of nitric oxide and its role in a variety of specific infections ranging from sepsis, tuberculosis and malaria to viral myocarditis, influenza, and AIDS.

''Informative, well-constructed, and readable...The contributors are leaders in their fields and what they have to say is worthwhile.'' --- SGM Quarterly, August 1998

In recent years increased scientific attention has been given to immediate defense mechanisms based on non-clonal recognition of microbial components. These mechanisms constitute the innate immunity arm of the body s defense. Identification of pathogens by these mechanisms involves primarily receptors recognizing sugar moieties of various microorganisms. Innate immunity based mechanisms are essential for the existence of multicellular organisms. They are evolutionarily conserved and designed to provide immediate protection against microbial pathogens to eradicate infection. Activation of innate immunity is crucial for transition to specific immunity and for its orientation, and to assist the specific immune response in the recognition of pathogens and their destruction. Innate immunity is regularly involved in the arrest of bacterial, mycotic, viral and parasitic infections, giving the specific immune response time to become effective. It becomes critically essential in immunocompromised patients who fail to mount specific immune responses due to congenital or acquired immunodeficiencies as a result of chemotherapy, dialysis, immunosuppressive drugs, or HIV infection. The Innate Immunity arsenal constitutes polymorphonuclear and mononuclear phagocytes, mast cells, the complement system, Natural Killer cells, antimicrobial peptides, and presumably a subset of T lymphocytes with TCRl receptors.