The Streptomycetes are industrially widely used microorganisms due to their ability to produce numerous different chemical compounds. These show very varied effects upon other living systems, and result from profound and subtle biochemical and morphological differentiation during the streptomycete life cycle. It is therefore not surprising that research on the genetics of antibiotic biosynthesis and differentiation in this group is currently progressing rapidly in many countries. Intimately connected with the production of antibiotics is resistance to them; analysis of this is giving further information about the origin and evolution of this class of genes and their hypothesized spread among other microorganisms. Another interesting feature of the Streptomyces group is their mycelial growth. Also, their ecologically important utilization of high molecular weight compounds requires enzymes to be transported outside the cell to hydrolyze non-diffusible substrates. Finally, we have as yet limited understanding of the various mechanisms of genome rearrangement observed in some of these species; deletions and/or amplifications of enormous amounts of DNA can occur without seriously affecting the viability of the organism under laboratory conditions. The present volume, which includes contributions addressing the above subjects and others, originates from a meeting on "Genetics and Product Formation in Streptomyces" sponsored by the Federation of European Microbiological Societies in Erfurt on May 1-6 1990. Compared to previous ones of this kind held in 1979, 1983 and 1987 in Weimar, one can point to impressive progress in the study and applications of Streptomyces genetics.

The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having only recently passed 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, biochemical cytology, and high-resolution microscopy and spectroscopy, the field has experienced a genuine information explosion. Few serious attempts have so far been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of about 22 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 as well as to develop an invaluable 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."

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, biochemical cytology, and high resolution microscopy and spectroscopy, 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 22 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 invalu able 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."

The fIrst reports on the tropism of the human immunodefIciency virus (HIV), then called human T-celilymphotrophic virus type ill (HTLY- ill) or lymphadenopathy associated virus (LA V), indicated an almost absolute specifIcity of the virus for T4 (helper/inducer) lymphocytes. It became apparent a few years later that macrophages were also infectable by HIV. The common cellular receptor for the virus on these cell types was CD4. A remarkable series of studies by fIve different groups, four of which were published in the same issue of~, showed that recombinant soluble CD4 could inhibit the infectivity of the virus. Subsequent studies began to reveal, however, that cells not expressing CD4 could also be infected, thus raising the possibility that almost any cell in the body could act as a latent reservoir for the virus. Recent observations that the infectivity of patient isolates is not inhibited at the low concentrations of rsCD4 that inhibit laboratory strains, also indicate the importance of CD4-independent mechanisms. The mechanisms of fusion of my with cellular membranes are under investigation by a large number of laboratories. These studies range from the determination of the oligomeric structure of the envelope glycoproteins, to the analysis of the function of various regions of the proteins by site-directed mutagenesis, to the fluorimetric monitoring of membrane fusion. This book originated as the proceedings of a Workshop on the Mechanisms and Specificity of HIV Entry into Host Cells, held at the University of California, San Francisco in June 1989.

This volume is based on the program of the International Conference on Drugs of Abuse, Immunity and Immunodeficiency held in Clearwater Beach, Florida. It was sponsored by the University of South Florida College of Medicine with the support of the National Institute on Drug Abuse. During the past few decades, drugs of abuse, including marijuana, cocaine, opiates and alcohol, have been studied by biomedical scientists in terms of the systemic effects of the drugs as well as alterations in neurophysiology and the psychology. More recently, the scope of such investigations has been broadened to include alterations within the immune system, and the influence of altered immunity on physiological and psychological consequences of drug abuse. In this regard, participants in the Clearwater Beach conference provided new information concern ing both basic and clinical aspects of drugs of abuse and immunity, especially immunodeficiency. Advances have been made in recent years in understanding the nature and mechanisms regulating the immune response and the mechanisms by which drugs may influence immune responses. In particular, the emergence of psychoneuroimmunology as a new discipline has heightened interest in immune responses influenced by psychoactive drugs. This has resulted in interdisciplinary investigations involving clinical and basic scientists including microbiologists, immu nologists, physiologists, psychiatrists, oncologists and others. The recreational use of the above mentioned drugs by large numbers of individuals has aroused serious concern about the consequences of this activity.

Mammalian Toll-like receptors (TLRs) were first identified in 1997 based on their homology with Drosophila Toll, which mediates innate immunity in the fly. In recent years, the number of studies describing TLR expression and function in the nervous system has been increasing steadily and expanding beyond their traditional roles in infectious diseases to neurodegenerative disorders and injury. Interest in the field serves as the impetus for this volume in the Current Topics in Microbiology and Immunology series entitled "Toll-like receptors: Roles in Infection and Neuropathology." The first five chapters highlight more traditional roles for TLRs in infectious diseases of the CNS. The second half of the volume discusses recently emerging roles for TLRs in non-infectious neurodegenerative diseases and the challenges faced in these models with identifying endogenous ligands. Several conceptual theories are introduced in various chapters that deal with the dual nature of TLR engagement and whether these signals favor neuroprotective versus neurodegenerative outcomes. This volume should be informative for both experts as well as newcomers to the field of TLRs in the nervous system based on its coverage of basic TLR biology as well as specialization to discuss specific diseases of the nervous system where TLR function has been implicated. A must read for researchers interested in the dual role of these receptors in neuroinfection and neurodegeneration.

It has been 10 years since the Plenum Publishing Corporation printed a series of review articles on bacteriophages in Comprehensive Virology. Articles in that series contained physical-genetic maps but very little DNA sequence information. Now the complete DNA sequence is known for some phages, and others will soon follow. During the past 10 years, two phages have come into common use as reagents: A phage for cloning single copies of genes, and M13 for cloning and DNA sequencing by the dideoxy termination method. Also during this period the use of alter native sigma factors by RNA polymerase has become established for and T4. This seems to be a widely used mechanism in bacteria, SPO 1 since it has been implicated in sporulation, heat shock response, and regulation of nitrogen metabolism. The control of transcription by the binding of A phage CII protein to the -35 region of the promoter is a recent finding, and it is not known how widespread this mechanism may be. This rapid progress made me eager to solicit a new series of reviews. These chapters are of two types: each of the first type deals with an issue that is exemplified by many kinds of phages. Chapters of this type should be useful in teaching advanced courses. Chapters of the second type pro vide comprehensive pictures of individual phage families and should pro vide valuable information for use in planning experiments."

The emergence of H5N1 avian influenza in 1997 and of the influenza A H1N1 of swine origin in 2009 calls for new, rapid and sustainable solutions for both seasonal and pandemic influenza viruses. During the last ten years, science and technology have made enormous progress, and we are now able to monitor in real time the genetics of viruses while they spread globally, to make more powerful vaccines using novel adjuvants, and to generate viruses in the laboratory using reverse genetics. This volume not only provides state-of-the-art information on the biology of influenza viruses and on influenza vaccines, but is also designed to be a resource to face the present H1N1 pandemic and to plan for long-term global and sustainable solutions.

Autophagy is a fundamental biological process that enables cells to autodigest their own cytosol during starvation and other forms of stress. It has a growing spectrum of acknowledged roles in immunity, aging, development, neurodegeneration, and cancer biology. An immunological role of autophagy was first recognized with the discovery of autophagy's ability to sanitize the cellular interior by killing intracellular microbes. Since then, the repertoire of autophagy's roles in immunity has been vastly expanded to include a diverse but interconnected portfolio of regulatory and effector functions. Autophagy is an effector of Th1/Th2 polarization; it fuels MHC II presentation of cytosolic (self and microbial) antigens; it shapes central tolerance; it affects B and T cell homeostasis; it acts both as an effector and a regulator of Toll-like receptor and other innate immunity receptor signaling; and it may help ward off chronic inflammatory disease in humans. With such a multitude of innate and adaptive immunity functions, the study of autophagy in immunity is one of the most rapidly growing fields of contemporary immunological research. This book introduces the reader to the fundamentals of autophagy, guides a novice and the well-informed reader alike through different immunological aspects of autophagy as well as the countermeasures used by highly adapted pathogens to fight autophagy, and provides the expert with the latest, up-to-date information on the specifics of the leading edge of autophagy research in infection and immunity.

The study of viruses necessarily involves dissecting the intimate details of cellular pathways. Viruses have often been employed as tools in studying cellular pathways, as was done by early retrovirologists such as Peyton Rous in attempting to understand the mechanism of cellular transformation and oncogenesis. On the other side of the coin, virologists seek to de?ne those cellular elements interacting intimatelywiththeir virus ofinterestinorder to better understand viral replication itself, and in some cases to develop antiviral strategies. It is in the intersection of virology and cell biology that many of us ?nd the most rewarding aspects of our research. When a new discovery yields insights into basic cellular mechanisms and presents new targets for int- vention to ?ght a serious pathogen, the impact can be high and the excitement intense. HIV has been no exception to the rule that viruses reveal many basic aspects of cellular biology. In recent years, in part because of the importance of HIV as a major cause of human suffering, numerous cellular processes have been elucidated through work on processes or proteins of this human retrovirus. The excitement in this ?eld is especially well illustrated by the discovery of new innate means of resisting viral replication, such as the work on APOBEC3G, TRIM5a, and BST-2/ tetherin presented in this volume.

Deficiencies in any of the defense mechanisms of the host can lead to severe microbial infections; these are of clinical relevance. Broad up-to-date knowledge in this field allows identification of many unspecific as well as highly specific defense reactions involved in the struggle against infectious diseases. On the other hand, protective structures on the microbial cell surfaces have been adapted and improve the counterpart's chances of survival. In particular, it has been considered that the great diversity of the bacterial envelopes not only determines the anatomical location of the tissue injury but also induces activation of distinct parts of the complex defense system. The specific defense mechanism, whose most prominent constituent is provided by the antibo

The Bunyaviridae represent an extremely diverse family of viruses, whichuntilrecentlywererelativelypoorlyunderstood. These viruses have become increasingly important in both human and veterinary medicine, and, most recently, bunyaviruses have been recognized as plant pathogens as well. This book attemptsto treat all aspectsof their biology, including their natural history, genetics, virion structure, unusual pathway of intracellular assembly, gene structure and the mechanisms of its expression, antigenicity, and pathogenesis, inasinglevolume. Assuch, itfillsavoid inthe virologyliterature.Thisvolumeisalsotimely, asthemolecular descriptionofthisfamilyisnowalmostcomplete. Thereader can expect to find the present state of the art on how bunyavirusesaremaintainedinnature, andhowtheyreplicate and sometimescausedisease. Iwould like tothank myco-contributorsfor the time and efforttheyhaveinvestedtomaketheirchaptersascompleteas possible, and notleastofall, for byand largerespectingthe deadline. Iam alsogratefulto DickCompansforsuggesting this volume and helping to design its contents, and for the manydiscussionsduring hisstayin Geneva. DANIEL KOLAKOFSKY ListofContents C. R. PRINGLE: TheBunyaviridaeandTheirGenetics An Overview . . . . . . . . . . . . . . . . . . . . . B.J. BEATYand C. H. CALISHER: Bunyaviridae- Natural History. . . . . . . . . . . . . . . . . . 27 M.J. HEWLETTand W. CHIU: Virion Structure . . 79 R. M. ELLIOTT, C. S. SCHMALJOHN.and M. S. COLLETT: BunyaviridaeGenomeStructureandGeneExpression 91 D. KOLAKOFSKYand D. HACKER: BunyavirusRNA Synthesis: GenomeTranscriptionand Replication. 143 Y. MATSUOKA, S. Y. CHEN, and R. W. COMPANS: BunyavirusProteinTransportandAssembly. 161 L. KINGSFORD: AntigenicVariance. . . . . . . . 181 F.GONZALEZ-SCARANO, M. J. ENDRES.and N. NATHANSON: Pathogenesis. . . . . . . . . . . . . . . . . . . . . . ... 217 ListofContributors BEATY, B. J.... 27 HACKER. D.... 143 CALISHER, C. H.. 27 HEWLETT, M. J. 79 CHEN, S.Y . 161 KINGSFORD, L.. 181 CHIU, w. . 79 KOLAKOFSKY D.. 143 COLLETT, M.S. . 91 MATSUOKA, Y.. 161 COMPANS, R. W.. 161 NATHANSON, N.. 217 ELLIOTT, R. M.. . 91 PRINGLE, C. R.. . 1 ENDRES. M. J. . . 217 SCHMALJOHN. C.S.. 91 GONZALEZ-S

It has been known for a long time that the majority of plant viruses contain RNA and in the past decade and a half it has been realized that many have genomes consisting of three molecules of single-stranded RNA with positive polarity. Among these are viruses belonging to four groups recognized by the International Committee for Virus Taxonomy: the Bromovirus and Cucumovirus groups whose genomes are encapsi dated in small icosahedral particles or the Ilarvirus and alfalfa mosaic virus groups with spheroidal or bacilliform particles. In addition to their tripartite genomes, these viruses share a number of other properties and it has been proposed that they should perhaps be grouped in a single virus family for which the name Tricornaviridae has been suggested, the tri indicating the tripartite nature of the genome, the co emphasizing the cooperation of the three genome parts required to initiate infection, and the rna indicating that the genome is composed of RNA. Viruses of this "family" are less uniform in their biological proper ties. A number of them are widespread, causing very destructive plant diseases. Viruses such as those of cucumber mosaic and alfalfa mosaic have very extensive host ranges and are responsible for serious crop losses in many parts of the world. Others such as prunus necrotic ringspot or prune dwarf viruses are more restricted in their host ranges but never theless infect important perennial hosts such as stone fruits and reduce productivity considerably."

The data summarized in this chapter show that morphological transformation and oncogenesis by adenoviruses are brought about by the coordinated activity of regions E1A and E1B. Gene products of each of these subregions appear to fulfill distinct roles in oncogenic transformation, with the possible exception of the product(s) encoded by the O. 9-kb E1A mRNA. Also unclear is the func- tion of the 20-kd E1B protein, which has a small role, if any, in morphological transformation, but appears to be essential for the development of the oncogenic phenotype, as defined by the ability of transformed cells to grow in immuno- deficient nude mice. The differences in biological properties of oncogenic and nononcogenic adenoviruses must be attributed to differences in the primary structure of the respective E1A and E1B gene products, in particular of the product(s) of the 1. 0-kb E1A mRNA and of the 55-kd protein encoded by the 2. 2-kb EiB mRNA. The availability of cold-sensitive adenovirus mutants has enabled us to conclude that the transformed phenotype is maintained as a result of continuous expression of at least region E1A gene products, and is therefore not the result of a hit-and-run mechanism. Despite the progress in our understanding of adenovirus transformation and oncogenesis, virtually nothing is known about the precise mechanism by which the viral gene products bring about the neoplastic changes in cells. The only exception is the demonstration that Ad12 region E1A (1.

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, biochemical cytology, and high-resolution microscopy and spectroscopy, 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 22 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 invaluable 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."

Our gut is colonized by numerous bacteria throughout our life, and the gut epithelium is constantly exposed to foreign microbes and dietary antigens. Thus, the gut epithelium acts as a barrier against microbial invaders and is equipped with various innate defense systems. Resident commensal and foreign invading bacteria interact intimately with the gut epithelium and can impact host cellular and innate immune responses. From the perspective of many pathogenic bacteria, the gut epithelium serves as an infectious foothold and port of entry for disseminate into deeper tissues. In some instances when the intestinal defense activity and host immune system become compromised, even commensal and opportunistic pathogenic bacteria can cross the barrier and initiate local and systematic infectious diseases. Conversely, some highly pathogenic bacteria, such as those highlighted in this book, are able to colonize or invade the intestinal epithelium despite the gut barrier function is intact. Therefore, the relationship between the defensive activity of the intestinal epithelium against microbes and the pathogenesis of infective microbes becomes the basis for maintaining a healthy life. The authors offer an overview of the current topics related to major gastric and enteric pathogens, while highlighting their highly evolved host (human)-adapted infectious processes. Clearly, an in-depth study of bacterial infectious strategies, as well as the host cellular and immune responses, presented in each chapter of this book will provide further insight into the critical roles of the host innate and adaptive immune systems and their importance in determining the severity or completely preventing infectious diseases. Furthermore, under the continuous threat of emerging and re-emerging infectious diseases, the topic of gut-bacteria molecular interactions will provide various clues and ideas for the development of new therapeutic strategies.

attempted to cover metabolic matters already reviewed in Volumes I and II of The Biochemistry and Physiology of Protozoa (eds. Lwoff, and Lwoff and Hutner). To those interested in the broader aspects of photo- synthesis and photoreception, reference is made to Photosynthesis and Related Processes, Volume I, and parts I and 2 of Volume II, by E. Rabinowitch; the Brookhaven Symposium on The Photochemical Ap- paratus: Its Structure and Function (1959); the New York Academy of Sciences conference on Photoreception (1958), and to the many recent symposia, reviews, and current journal literature. This book is primarily concerned with the use of Euglena in study- ing photoreception; it is also hoped that biologists, biochemists, and biophysicists will find in Euglena a remarkably versatile research tool for attacking some of their problems. I would like to thank Drs. S. H. Hutner and L. Provasoli of the Haskins Laboratories for introducing me to Euglena as an exceptional experimental "animal," as well as for many stimulating discussions and continued enthusiasm. I am indebted to Drs. G. E. Palade and K. R.

The book provides a comprehensive account of ticks and tick-borne diseases occurring in tropical and subtropical areas. It begins with a complete up-to-date overview of the systematics of the Ixodida (Ixodidae, Argasidae and Nutalliellidae) and is followed by a review of the problem of ticks and tick-borne diseases of domestic animals world wide. This leads on to multi-disciplinary approaches to planning tick and tick-borne disease control and to contributions on calculating the economic impact of a tick species such as Amblyomma americanum on beef production systems. Heartwater fever (cowdriosis) and dermatophilosis are endemic in Africa and pose a threat to the North American mainland. The epidemiology of these two diseases is discussed in detail as is the role of frozen vaccines to control bovine babesiosis and anaplasmosis. The book also includes chapters on tick transmitted zoonoses such as Lyme borreliosis, tick typhus and ehrlichiosis. It concludes with a review of the acaricidal treatment of tick infestation.

Tuberculosis once again occupies a special position in the areas of infec tious diseases and microbiology. This disease has been important to mankind since even before biblical times. Tuberculosis has been a major cause of morbidity and mortality in humans, especially in highly ur banized Europe, until a few decades ago. Indeed, this disease became a center of many novels, plays, and operas, since it appeared to be quite popular to have the heroine dying of "consumption. " Most importantly, tuberculosis also became the focus of attention for many investigations during the 19th and even the 20th centuries. Major advances were made in the areas of isolation and identification of M. tuberculosis and related microorganisms. The discovery, by Robert Koch, that tuberculosis was caused by an infectious agent revolutionized our thinking about dis eases. Koch's postulates were developed with tuberculosis in mind and became a focal point for many advances in microbiology and medicine. Studies with mycobacteria as a central focus have also led to revolu tionary new concepts about immunology in general. Koch himself showed that those exposed to M. tuberculosis develop a skin hypersen sitivity or allergy to the microorganism's antigens, an observation which was the starting point for many important developments. Indeed, imme diate-type hypersensitivity and atopic or IgE-mediated allergy were de fined in relation to the delayed-type cutaneous hypersensitivity evi denced with the tubercle bacillus."

The modem microbiologist is often a real specialist who has difficulty under standing and applying many of the techniques beyond those in his or her own immediate field. On the other hand, most benefits to modem microbiology are obtained when a broad spectrum of scientific approaches can be focused on a problem. In early studies, electron microscopy was pivotal in understanding bacterial and viral morphology, and we still feel that we will understand a disease better if we have seen an electron micrograph of the causative agent. Today, because there is an increased awareness of the need to understand the rela tionships between microbial structure and function, the electron microscope is still one of the most important tools microbiologists can use for detailed analysis of microorganisms. Often, however, the aforementioned modem microbiologist still thinks of ultrastructure as involving negative staining or ultrathin sectioning in order to get a look at the shape of a "bug. " Many of the newer ultrastructure techniques, such as gold-labeled antibody localization, freeze-fracture, X-ray microanalysis, enzyme localization, and even scanning electron microscopy, are poorly under stood by, and therefore forbidding to, the average microbiologist. Even many cell biologists admit to having difficulty staying in touch with current develop ments in the fast-moving field of electron microscopy techniques."

All but one* of the following articles represent comprehensive reports on a workshop held between 7 and 9 May 1981 at the Institute of Virology and Immunobiology, University of Wfuzburg, Federal Republic of Germany. The title of the workshop was "The Involvement of Endogenous Retroviruses inN ormalFunction and Pathological Growth of Lymphocytes." Rather than collecting and printing manuscripts of the individual communications, the organizers asked selected parti cipants to write, after the workshop, concise articles each compris ing several contributions and discussions on major topics. In so doing, we hope to present to a larger audience a synopsis of the various information and views exchanged at the meeting. Such a procedure seemed the more appropriate as the workshop was intended to bring together specialists from two rather diverse fields: RNA-tumor virology and immunobiology. While this created some initial problems of terminology, it was quite effective in making representatives of one field more aware of the significance and the contributions ofthe other. It also great ly contributed to realization of the complexity of the problems involved in virus-induced leukemogenesis."

of McGill University of Montreal, Canada, who talks about artifi cial cells prepared from semipermeable microcapsules. Also illustrative of this method is a contribution on microencapsulated pesticides by C. B. Desavigny and E. E. Ivy of Pennwalt Corporation. Another method of polymerization in situ is micro encapsulation by vapor deposition, the subject of W. M. Jayne of Union Carbide Corporation. The more mechanical methods of microencapsulation are represented by two techniques, one involving a fluidized bed the other involving mainly a centrifugal method. The fluidized bed method is covered in a paper by H. Hall and T. M. Hinkes of the Wisconsin Alumini Research Foundation. The centrifugal and other related methods are treated by Mr. J. E. Goodwin and Mr. Sommerville of the Southwest Research Institute of San Antoni~ Texas. Dr. G. Baxter of Moore Business Forms, studied capsules made by mechanical methods as well as by chemical methods. Mr. Russell G. Arnold of the Bureau of Veteranary Medicine of the Food and Drug Administration draws our attention to the procedures to be used for securing approval of a new animal drug application for the marketing of microencapsulated products. And last but not least, we have a contribution by Mr. G. O. Fanger on "Micro encapsulation a Brief History and Introduction, whose title speaks for itself.

No one whose opinion deserves a moment's consideration can doubt that most of the great positive evils of the world are in themselves removable, and will, if human affairs continue to improve, be in the end reduced to narrow limits. J. S. Mill, Utilitarianism, II, 1863 Mill was not writing about herpesviruses, but had he known them as we do, he would have included them among the great positive evils of the world. They cause disease and premature death, and are very costly to our society. There is no loftier aim than to cure or prevent human infections with these viruses. The objective of much of the current research on herpesviruses is directed toward an understanding of the molecular mechanisms involved in initiation of infection, establish ment and termination of latent state, virus multiplication, and the destruction of cells which ultimately is the basis of the diseases caused by these viruses. At no time during the past 80 years, since members of the herpesvirus family were first discovered, has there been so much progress in our understanding of the biology of these viruses as in the past few years. Along with the development of a greater understanding of the molecular biol ogy of the well-known herpesviruses we have witnessed the isolation of new human herpes viruses.

When Antibiotics I was published in 1967, the teleological view was held by some that" antibiotics" were substances elaborated by certain microorgan isms for the purpose of competing with other microorganisms for survival in mixed ecological environments. However, not only had J. EHRLICH and his associates shown 15 years earlier that chloramphenicol was produced by Strepto myces venezuelae in cultures of sterilized soils but not in parallel cultures of the same soils which were not sterilized, but operationally, the search for anti cancer antibiotics was actively under way (Antibiotics I reporting on numerous such substances), although the concept of antibiosis could not logically justify such undertakings. This editor hesitates to accept the use of the term "antibiotic" for anti microbial agents of non microbiological origins which is sometimes encountered, but neither does he subscribe to the view that antibiotics are in some fundamental manner different from chemotherapeutic substances of other origins. Modes and mechanisms of action of chemotherapeutic compounds are not systematic functions of their origins nor of the taxonomical position of the target organisms. Consequently, in the selection of topics for Antibiotics III (published in 1975), synthetic drugs and natural products of higher plants (alkaloids) were represented, along with antibiotics in the strict sense of the definition. We now present Antibiotics V, for whose assembly the same selection criteria were applied as for Antibiotics Ill. The aggregate length of the contributions rendered it impractical to place the entire text between the covers of one book."