What regulation shall we have for the operation? Shall a man transfuse he knows not what. to correct he knows not what. God knows how (l)? Dr. Henry Stubbs Royal College of Physicians circa 1670 If dialysis therapy were a new phannaceutical product being evaluated by the FDA now, it might not be approved for marketing. The recommended dose, its potential toxicity, the side effects of under-or over-dialysis as well as its efficacy have been the subject of very few studies. The high mortality rate associated with the treatment may raise a few eyebrows. That it is a life-saving modality of treatment is undoubtedly true for more than 100,000 patients in the United States and for more than a million patients world wide. Because dialysis has extended the lives of many people by a variable period of time, most nephrologists have "rested on their laurels" and did not vigorously pursue studies to optimize these treatments. But facts have a way of intruding in all our lives and the facts are that the overall mortality rate of dialysis patients in the United States is rising and stands close to 25% per year and is closer to 33% per year for patients between the ages of 65 and 74 (2). These mortality figures are considerably higher for age-adjusted dialysis populations in Europe and particu larly in Japan, and certainly for the age-adjusted nonnal population."

Renal stone disease remains a common clinical problem. Patients m a y attend either medical or surgical clinics and n o t infrequently present as acute abdominal emergencies to general practitioners, physicians, surgeons and even gynaecologists. Recent urinary calculi continue to cause considerable morbidity despite the recent advances in our understanding of the pathogenesis of the different types of stones involved and despite improvements in t reatment- by appropriate drug therapy, by ultrasound techniques and by lithotripsy. This volume discusses the investigation and management o f patients with calculus disease. Each chapterhas been written by a n experienced clinician and provides information of considerable relevance and importance for all doctors engaged in clinical practice. The technical developments o f the last few years have clearly demonstrated that renal stone disease, even when recurrent, should be an uncommon cause of chronic renal failure. Knowledge o f the recent developments in this field is important for all practising doctors and even more important for their patients.

When the external Quinton-Scribner arteriovenous shunt was developed in 1960, and, a little later, the internal Brescia-Cimino arteriovenous fistula was developed as a vascular access for hemodialysis, thereby making possible regular dialysis therapy of chronic uremic patients, many nephrologists became surgeons, having learned the type of vascular surgery related to hemodialysis quite well. The same series of events occurred with regards to peritoneal dialysis with the introduction of the Tenckhoff catheter and the need for gaining a permanent access to the peritoneum for chronic ambulatory peritoneal dialysis (CAPD) therapy. With time, however, problems relating to vascular and peritoneal access have forced many nephrologists to give up their surgery; meanwhile, many surgeons have become quite expert in some sophisticated techniques relating to dial ysis (e. g., vessel grafting, prosthesis implantation, etc.). Today, whether or not involved in this type of surgery, both nephrologists and surgeons remain interested in knowing all available access devices for dialysis as well as the surgical techniques involved. However, all nephrologists involved in dialysis must know how to prevent or treat complications related to dialysis access. Thus, it appeared to me to be quite advisable to have a book in my series, Topics in Renal Medicine, dealing with vascular and peritoneal access for dialysis.

We are pleased to present to our readers the Proceedings of the Fifth International Workshop on Phosphate and Other Minerals which was held in New York City, New York, U.S.A during September 23-27,1981. It was hosted by Joseph M. Letteri, M.D., Professor of Medicine at the State University of New York at Stonybrook School of Medicine, and Chief, Division of Nephrology, Nassau County Medical Center. As in the previous Workshops, this meeting provided an oppor tunity for interested scientists from interrelated fields, including nephrology, endocrinology, physiology, biochemistry and nutrition, to get together and discuss the recent advances in the field of phosphate and mineral metabolism. There were 29 invited presenta tions by leading scientists and 40 oral and 90 poster presentations selected from over 250 abstracts submitted to the Organizing Committee. The Workshop was attended by 250 scientists from 14 countries including Austria, Australia, Canada, Denmark, England, France, Germany, Holland, Israel, Italy, Japan, Sweden, and the United States of America. The Sixth International Workshop on Phosphate and Other Minerals will be held during June 24-26, 1983 in Verona, Italy. It will be hosted by Professor Giuseppe Maschio, Director, Division of Nephrology, Istituti Ospitalieri, Verona, Italy. The theme of this coming Workshop will continue to focus on the pathophysiology of phosphate homeostasis and the metabolism of other minerals."

We are pleased to present to our readers the Proceedings of the Fourth International Workshop on Phosphate and Other Minerals which was held in Strasbourg during June 22-24, 1979. It was hosted by Professor Henri Jahn, Professor of Medicine and Chief, Department of Nephrology at the University of Strasbourg. These Workshops have become a tradition in the scientific scene of mineral metabolism. The meetings have been providing a unique framework for close interaction between scientists from various disciplines, such as nephrologists, endocrinologists, bio chemists, nutritionists, and those dealing with bone metabolism. The Workshops also created a forum for the delivery of original information, as well as state-of-the-art presentations on exciting topics of current interest in this evergrowing field of phosphate and mineral homeostasis. The Fourth International Workshop was attended by three hundred scientists from 15 countries including Austria, Canada, Denmark, England, France, Germany, Holland, Israel, Italy, Japan, Sweden, Switzerland and the United States of America. The topics discussed included those dealing with the renal handling of phos phate, calcium and magnesium, intermediary phosphate metabolism and phosphate homeostasis in health and disease. Two symposia were also presented: one dealt with nephrolithiasis and its rela tion to phosphate and the other with bone metabolism. In addition to 22 presentations by invited speakers, the Workshop provided 46 oral and 93 poster presentations selected from over 250 abstracts submitted to the Organizing Committee."

Serious disturbances of fluid and electrolyte balance are frequently encountered in acutely ill patients; somewhat less often in the chronically sick. There seems to be a trend for such cases to increase, due probably to an increase in major surgical procedures on older patients whose renal function is less than adequate. There are already many publications dealing with the physiology of the homeo stasis of fluid and electrolytes, and others dealing with the clinical aspects of the subject. It is often assumed that a knowledge of the basic principles of physiology will enable the doctor to prescribe suitable intravenous therapy. In practice this is often found not to be so and the evidence for this is the frequency of calls for help with electrolyte problems from well-qualified and experienced doctors who are undoubtedly equipped with adequate or even excellent knowledge of the basic It is not an unusual observation that knowledge of theory and principles involved. principles does not necessarily lead to successful practice in this or any other art or craft. Most doctors already possess knowledge of the physiology of the internal envi ronment, but some are aware of being unable to deal effectively with clinical problems related to fluid and electrolyte disturbances and seek guidance to translate theoretical knowledge into practice."

The mechanisms by which animals regulate the volume and composition of their body fluids has long had a particular fascination for students of biology. As a consequence, the subject can lay claim to an impressive record of ground breaking scientific achievements as well as a provocative body of philosophical speculation concerning the role of the system in the origin and evolution of life. Indeed, the entire concept of homeostasis on which so much of o r current biologic thinking is based, derives from Claude Bernard's pioneering exploration of the forces that determine the composition of this 'internal sea'. Other seminal achievements credited to this area of inquiry include the first description of a genetically transmitted human disease (familial neurogenic diabetes insipidus); the first isolation sequencing and synthesis of a peptide hormone (vasopressin and oxytocin); the first demonstration of peptide hormone synthesis by way of a larger protein precursor; the first description of resistance to the biologic actions of a hormone (nephrogenic diabetes insipidus); and the conceptual realization of the unique counter-current mechanism that permits concentration of the urine. This record of far reaching and fundamental advances has been distinguished by many fruitful inter actions between clinical and basic science."

This book in the Topic Pack series covers some of the commoner and some of the rarer nephrological diseases. Owing to their diverse nature a 'traditional' approach, i.e. one considering pathogenesis, symptoms, signs and treatment, has been used. This inevitably leads to some repetition but the reader should be con stantly reminded that apparently trivial symptoms such as fre quency, dysuria, etc. may be the clues to more fascinating pathol ogy. In addition, where relevant, attempts have been made to remind the reader of some basic renal physiology in order to understand the results of pathological changes, those changes being illustrated by renal histology, specimens and radiographs. John Walls, Leicester General Hospital, 1. Urinary Tract Infections Infection of the urinary tract is the commonest renal disease seen in nephrological practice and second only to infections of the respiratory tract in overall clinical practice. With the widespread and early use of antibiotics over the past three decades it was hoped that some of the problems caused by urinary tract infec tions would be eliminated. However, this has not proved so, as the figures from the European Dialysis and Transplant Association Register (1975) have shown (Figure 1). 'Pyelonephritis' is the Figure 1. The main causes of end stage renal failure (from the European Dialysis and Transplant Association Register 1975)."

RICHARD J. GLASSOCK Introducing a scientific symposium is an uncertain and difficult task. The remarks must not be too specific lest the participant's later contributions be intruded upon, yet an overview of the goals and objectives of the conference should be presented in an inquisitive and stimulating fashion. Perhaps a compromise position would be to make a few general statements and pose a limited number of questions which hopefully would then be addressed dur ing the formal or informal portions of the meeting. A conclusion incorpo of the relevance of the specific topic to the more rating some perspectives global issues of disease and its consequences might be appropriate. The goals and objectives of this conference, as set forth by its organizers, Professors Ponti celli, D'Amico and Minetti, are rather simple and straight forward; namely, to review and elucidate the immunopathophysiology of cryoimmunoglobulins and auto-antibodies to immunoglobulins (lg) and, secondarily, to explore the possible participation of these disordered states in glomerular injury. As such, this conference is principally devoted to an analysis of two properties of certain species of the globulin fraction of serum proteins, specifically the ability to self associate on the basis of immune interactions and to form insoluble aggregates when exposed to reduced ambient temperature. As we shall see, these two properties are often dis tinctly related."

In November 1986, I was invited to attend a symposium held in Barcelona on Diseases of the Pericardium. The course was directed by Dr. J. Soler-Soler, director of Cardiology at Hospital General Vall d'Hebron in Barcelona. During my brief but delightful visit to this institution, my appreciation of the depth and breadth of study into pericardial diseases, carried out by Dr. Soler and his group, grew into the conviction that these clinical investigators have accumulated a wealth of information concerning pericardial diseases, and that investigators and clinicians practicing in English speaking countries would greatly profit from ready access to the results of the clinical investiga tions into pericardial disease carried out in Barcelona. The proceedings of the Barcelona conference were published in a beauti fully executed volume in the Spanish language edited by Dr. Soler and pro duced by Ediciones Doyma. Because I believe that this work should be brought to the attention of the English speaking scientific and clinical com munities, I encouraged Dr. Soler to have the book translated into English. I knew that this task could be accomplished and that the book would be trans lated into good English without change of its content. My confidence was based upon a translation of my own book, The Pericardium, into Spanish undertaken by Dr. Permanyer, who is a contributor and co-editor of the pre sent volume."

Renal transplantation is now accepted as the treatment of choice for patients with end-stage renal failure. During the last decade both patients and graft survival rates have increased significantly and when assessed at one year are now greater than 90% and 80% respectively. These marked improvements have occurred at a time when increasing numbers of patients in the older age groups and with more complex forms of renal disease are being accepted for transplantation. The reasons for the improved clinical results are not fully understood but are probably linked with changes in blood transfusion policy, tissue typing policy and drug therapy. These topics, together with immunological monitoring and details of how to treat the highly sensitized patient, are fully covered in this volume. All the chapters have been written by recognized experts in their field. Not only are the recent advances well documented but the likely future developments in management are identified and discussed. As renal transplantation is now the single most common of treatment for renal failure, the information presented in this form volume should prove of value to all with an interest in current clinical practice.

Decoding the significance of proteinuria as an indicator of severity or prognosis in kidney disease is a stimulating challenge to students and practitioners of nephrology. Sir Richard Bright in 1827 associated pro with the disease that bears his name. In the subsequent more teinuria than a century and a half, however, the meaning of the linkage between proteinuria and renal disease remains elusive. Proteinuria is discovered on routine urinalysis in about 10 million Americans, most of whom express no symptoms of kidney disease, each year. From the studies of Robinson (updated in these pages), we know that proteinuria, per se, can be present for 20 years without change in re nal function, as described in orthostatic proteinuria. By contrast, pro teinuria may be the harbinger of swift kidney destruction, rarely cul minating in clinical collapse, a syndrome typifying "malignant proteinuria" as detailed herein by Avram. Although proteinuria is ubiquitous, an orderly management strategy for rational handling of proteinuria of less than nephrotic range is lack ing. Separation of tubular proteinuria and transient proteinuria of fever is now possible routinely. This book provides a record of the contribu tions of investigators and clinicians whose work forms the substrate for production of understanding and, ultimately, marching orders for prac titioners seeking optimized management for their proteinuric patients."

This is a book about renal cysts and cystic kidneys. Its contributors have created a resource of current information in a field that once aroused only curiosity, but that now stands at the leading edge of molecular nephrology. Its authorship includes 'oldtimers', who bring the wisdom of experience, and 'newcomers', whose presence attests to the contributions made by the investigative and technological advances of the past decade. Its text is organized to carry the reader from renal cyst to cystic renal disease. Each of its chapters defines or explores a challenge or an advance. Cells that line renal cysts are diverse in structure, type, and perhaps function. The cysts themselves lie within an interstitium that is not normal and may influence cyst development and growth. Experimental analogs of human disease offer increasing opportunities to basic researchers to examine, in sequence and under controlled circumstances, those events that favor nephron dilation, cyst growth and ultimate renal failure.

This is the 11th of the Pediatric Nephrology series created to help us be in touch with developments which are relevant to the problems we face daily in clinical practice and the questions we ask and try to answer in clinical and experimental research. Like volume IX, this one focuses on one of the subgroups to which we are committed--the neonates' special fluid and electrolyte requirements. This volume has more on blood pressure and renal function and looks at the hormonal regulators. There is greater depth about intoxications and nephrotic agents, congenital disorders and mineral metabolism. The exchanges were stimulating and the controversies were brought out without need of much of my usual prodding. At Julie Ingelfinger's suggestion, at the end of each panel discussion I have added a comment to highlight the main points as I see them. Otherwise, the format remains as in past editions: the papers given related to the four major topic areas, each followed by panel and registrant discussion. Although the transcription is almost verbatim, you will not find the names of the discussants, purposely omitted to ease my editorial work and to encourage everyone to speak candidly. Some of the questions and answers are those submitted to the panelists after the sessions, incorporated here by request. Also, frequent references are made to others' work but their names have been omitted.

For more than a generation haemodialysis has been the principal method of treating patients with both acute and chronic renal failure. Initially, developments and improvements in the system were highly technical and relevant to only a relatively small number of specialists in nephrology. More recently, as advances in therapy have dem onstrated the value of haemoperfusion for certain types of poisoning, the basic principles ofhaemodialysis have been perceived as important in many areas of clinical practice. In this volume, the potential advantages of bicarbonate haemo dialysis are objectively assessed, the technical and clinical aspects of both haemofiltration and haemoperfusion discussed and the con tinuing problems associated with such extracorporeal circuits analysed. All the chapters have been written by recognized experts in their field. The increasing availability of highly technical facilities for appropriately selected patients should ensure that the information contained in the book is relevant not only to nephrologists but to all practising clinicians."

Urinary tract infection remains one of the most common reasons for an individual seeking medical advice. Although the associated morbidity varies widely in adults, such infections are less common but may constitute severe, life-threatening illness in children and in the elderly. Diagnostic tests and treatment have been rationalized in recent years but many practising doctors still have difficulty in appreciating the patho-physiological principles involved. Particular difficulty is often experienced when treating patients with recurrent urinary tract infections, covert bacteriuria, vesico-ureteric reflux, elderly patients and those with indwelling catheters. These topics are fully discussed in this volume. Each chapter has been written by a recognized expert and practical aspects of patient management have been emphasized. The information presented in this volume should prove of interest not only to nephrologists but to all practising clinicians. VII ABOUT THE EDITOR Professor Graeme R. D. Catto is Professor in Medicine and Thera peutics at the University of Aberdeen and Honorary Consultant Phy sician/Nephrologist to the Grampian Health Board. His current interest in transplant immunology was stimulated as a Harkness Fellow at Harvard Medical School and the Peter Bent Brighton Hos pital, Boston, USA. He is a member of many medical societies includ ing the Association of Physicians of Great Britain and Ireland, the Renal Association and the Transplantation Society. He has published widely on transplant and reproductive immunology, calcium metab olism and general nephrology."

The need for adequate means by which to improve urine output is very old. Even in the "Scuola Salernitana", the oldest medieval medical school in Western Europe, about 1000 years ago it was taught how to improve urine output. The list of known "diuretica" included herbs, plants, roots, vegetables, in particular asparagus, fennel and carrot. The first diuretic drugs, however, were mercurial compounds. Thus, calomel, mercurous chloride, was initially used as a diuretic in the sixteenth century by Paracelsus, being one of the ingredients of the so-called "Guy's Hospital pill". But calomel had a cathartic effect so that it was replaced by organic mercurial compounds. These diuretics were clearly toxic. After the discovery of the car bonic anhydrase, in the early 1930s, and the introduction of sulfanilamide as a chemotherapeutic agent, it was observed that this drug was inhibiting carbonic anhydrase in vitro and urinary acidification in vivo thereby causing metabolic acidosis; urine output, however, appeared to increase. Subsequent studies led to the synthesis of more potent analogs, in particular acetazolamide. Studies on car bonic anhydrase inhibitors led to the synthesis of benzothiadiazides which disclosed much less inactivating action on carbonic anhydrase and much more diuretic effect through an inhibition of tubular transport of sodium and chloride. Chlorothiazide was the first member of this class of diuretics. Thiazides are still used in clinical practice.

CHARLES Y. c. PAK Major progress has been made in the pathophysiologic elucidation and management of nephrolithiasis during the past two decades. It is now possible to detect the cause of stone disease in more than 95% of patients, to prevent recurrent formation of stones in the majority of patients, and to remove most existing stones less invasively. The assumption of editorship of this book permits me to indulge in the discussion of this progress from my personal perspective. Three somewhat fortuitous events in my academic career dictated my directing major efforts in stone research. The first event occurred in 1963 when, after having completed medical training, I was faced with two years of military service as a participant of the Berry plan. Choices were limited and disconcerting for someone interested in a research career: a staff physician at a military installation or an indian reservation, or a member of a research team in a state penitentiary. An interesting article by Norman Gershfeld on phospholi pid monolayers prompted me to write him seeking a position in his laboratory of Health (NIH) in Bethesda, MD. Partly because of at the National Institutes my rudimentary exposure and publication in surface chemistry, I was offered a position as a staff scientist and a position in the Public Health Service which satisfied the requirements of a military service."

Fresh insights into the pathogenic mechanisms by which hyperglycemia induces tissue and organ injurt are the basis for rapidly evolving promising therapies in diabetes. Especially promising as targets for intervention are products of oxidative stress, including kinins and growth factors. Improving results of renal replacement regimes now incorporating pancreatic islet transplants are able to delay and prevent end-organ damage in diabetic individuals. The evolving story of the taming of diabetes is of direct concern to nephrologists, endocrinologists, ophthalmologists, primary care physicians and medical students.

Once dialysis treatment, in 1960, permitted life prolongation for some but not all patients in kidney failure, an ethical genie' was released. The introduction of peritoneal dialysis and kidney transplantation compounded the physician's dilemma by underscoring those left untreated. Who should be selected for uremia therapy? Should exclusion from treatment be properly delegated to administrators or physicians, or better left to a committee? Are some candidates more worthy than others? As examples: Do Presidents and Kings warrant priority in cadaver organ allocation over ordinary citizens? Are rich people more deserving than the poor? Is it ethical to choose a younger over an older patient? Can children and/or mentally incompetent persons serve as living organ donors? Is it proper to market organs under controlled circumstances? Eli A. Friedman, an experienced nephrology training program director, and Medical Advisor to the American Association of Kidney Patients, has collected 24 difficult cases that focus on these and other vexing though common stressful issues faced by those who manage kidney patients. Using a novel approach to each case, the opinions of lawyers, nephrologists, patients, and a transplant surgeon are proffered sequentially. Friedman asks and then answers searching questions arising from the debate. The quality of information presented is positively flavored by the fact that three of the respondents (one an attorney) are kidney transplant recipients. Members of the kidney team, those immersed in seeking truth in medical ethics, and all participating in exploring the legality or ethical basis of organ replacement will find this book pertinent to their effort.

We are pleased to present to our readers the proceedings of the Fourth Bari Seminars in Nephrology. The Topic of these proceedings deals with tubulo- interstitial nephropathies. The Bari Seminars in nephrology are bi-annual meetings attended by a large international audience comprised of clinician-scientists in the various disci- plines of nephrology and related fields. We trust that our readers will find the content of these proceedings reward- ing and interesting. We are indebted for the generous financial support of the Centro Nationale delle Richerche, Italy. Alberto Amerio Pasquale Coratelli Shaul G. Massry TUBULO-INTERSTITIAL NEPHROPATHIES 1 STRUCTURAL, ASPECTS OF THE RENAL INTERSTITIUM W.KRIZ AND K.V. LEMLEY Institute of Anatomy and Cell Biology, University of Heidelberg, D-6900 Heidelberg 1, F.R.G. Childrens Hospital of Los Angeles, Division of Nephrology, Los Angeles, U.S.A. The interstitium of the kidney includes the extravascular inter- tubular spaces of" the renal parenchyma, with their attendant cellular elements and extracellular substances. It is bounded on all sides by tubular and vascular basement membranes. The lymphatics are considered as part of the interstitium.

The last 20 years has seen an enormous increase in our knowledge about the management of patients with terminal renal failure. Despite this, even the most successful dialysis and transplant patients require long term specialist supervision so that renal units will have an incremental work load until the death rate of patients undergoing treatment equals the rate of intake of new patients. Furthermore, innumerable conditions which were once regarded as contraindications to therapy may no longer be seen in this light, so that the number of new patients coming forward for treatment each year is increasing rapidly. Dialysis and transplantation are expensive forms of treatment, in terms of staff, facilities and consumables, and it is therefore inevitable that there will be problems in providing treatment for all who need it. These will be particularly acute in times of economic crisis. This book contains the proceedings of a conference which was set up to explore the difference between the supply and the demand for treatment in the United Kingdom, to compare the situation with that in other countries, to explore possible solutions and possibly assign responsibility for the shortfall and to examine the practical and moral implications of our failure to treat the treatable.

For more than a generation haemodialysis has been the principal method of treating patients with both acute and chronic renal failure. Initially, developments and improvements in the system were highly technical and relevant to only a relatively small number of specialists in nephrology. More recently, as advances in therapy have dem onstrated the value of haemofiltration in the intensive therapy unit and haemoperfusion for certain types of poisoning, the basic principles of haemodialysis have been perceived as important in many areas of clinical practice. In this volume, the potential advantages of bicarbonate haemo dialysis are objectively assessed, the technical and clinical aspects of both haemofiltration and haemoperfusion discussed and the con tinuing problems associated with such extra corporeal circuits analysed. All the chapters have been written by recognized experts in their field. The increasing availability of highly technical facilities for appropriately selected patients should ensure that the information contained in the book is relevant not only to nephrologists but to all practising clinicians. ABOUT THE EDITOR Dr Graeme R. D. Catto is Professor in Medicine and Therapeutics at the University of Aberdeen and Honorary Consultant Phy sician/Nephrologist to the Grampian Health Board. His current inter est in transplant immunology was stimulated as a Harkness Fellow at Harvard Medical School and the Peter Bent Brighton Hospital, Boston, USA. He is a member of many medical societies including the Association of Physicians of Great Britain and Ireland, the Renal Association and the Transplantation Society."

The first sporadic observations describing renal abnormalities in diabetes were published late in the 19th century, but systematic studies of the kidney in diabetes started only half a century ago after the paper by Cambier in 1934 and the much more famous study by Kimmelstiel and Wilson in 1936. These authors described two distinct features of renal involvement in diabetes: early hyperfiltration and late nephropathy. Diabetic nephropathy is, despite half a century of studies, still a very pertinent problem, renal disease in diabetes now being a very common cause of end-stage renal failure in Europe and North America and probably throughout the world. It is a very important part of the generalized vascular disease found in long-term diabetes as described by Knud Lundbaek in his mono graph Long-term Diabetes in 1953, published by Munks gaard, Copenhagen. Surprisingly, there has not been a comprehensive volume describing all aspects of renal involvement in diabetes, and the time is now ripe for such a volume summarizing the very considerable research activity within this field during the last decade and especially during the last few years. This book attempts to cover practically all aspects of renal involvement in diabetes. It is written by colleagues who are themselves active in the many fields of medical research covered in this volume: epidemiology, physiology and pathophysiology, laboratory methodology, and renal pathology. New studies deal with the dia gnosis and treatment of both incipient and overt nephropathy by metabolie, antihypertensive, and dietary invention."

Since oxygen is mainly transported by diffusion within tissue, the oxygen pressure field reflects the local balance between oxygen supply and oxygen consumption and characterizes the state of oxygen supply. Despite large physiological varia- tions (e. g. , hypo-and hyperoxia, hypo-and hypertension, change of energy de- mand), this oxygen pressure field can remain remarkably constant, demonstrating that very effective mechanisms must exist that guarantee the adequacy of oxygen supply. Today, it is possible to describe in detail the responsible effector mecha- nisms that produce such a stable state of oxygen supply, but our knowledge of the reactions that sense tissue oxygen supply and trigger the regulatory responses is still incomplete. Since such knowledge is essential for understanding the system of oxygen supply and the way in which it has developed during evolution, even small progress is important. In this book the important O sensor reactions are discussed as they occur in 2 cells, organs, and organ systems. This broad approach gives an excellent picture of the actual state of knowledge in this field. Professor Dr. D. W. Lubbers Contributors Acker, H. Max-Planck-Institut fUr Systemphysiologie, Rheinlanddamm 201, 4600 Dortmund 1, FRG Bassenge, E. Institut fUr Angewandte Physiologie der Universitat Freiburg, Hermann-Herder-Stral3e 7, 7800 Freiburg, FRG Bingmann, D. Poliklinik fUr zahnarztliche Chirurgie, Universitat Mainz, Augustusplatz 2, 6500 Mainz, FRG Bauer, C. Physiologisches Institut, Universitat Zurich, Winterthurerstral3e 190, 8057 Zurich, Switzerland Busse, R. Institut fUr Angewandte Physiologie, Universitat Freiburg, Hermann-Herder-Stral3e 7, 7800 Freiburg, FRG Delpiano, M. A.