Controlled and predictable interference with hormonal feed- back mechanisms has become a major direction of preclinical and clinical research. There is a steadily increasing number of hormonal pep tides detected and characterized that are re- sponsible for endo-, para-, and autocrine cellular actions. Naturally, these peptides have been studied with regard to their cell growth stimulatory action and, in parallel, the re- spective antagonists are being investigated in terms of their antiproliferative (antineoplastic) function. Among the numerous pep tides of interest in this respect, somatostatin (somatotropin release inhibitory factor) and bombesin antagonizing factors have been the topic of inten- sive research during recent years. No presentation of the role of pep tides in oncology would be complete without a compre- hensive treatise of their physiological, preclinical and clinical functions in the context of their antineoplastic mechanism of action. Somatostatin and its various short- and long-acting analogs have the unique feature of suppressing and inhibiting a wide range of cellular processes including cell proliferation. Recep- tors for these peptides, which belong in a wider sense to the family of neuropeptides or neurotransmitters, are widely dis- tributed, a feature which is not in keeping with the general view of a growth hormone regulatory system. Thus, these substances are found in the gut in a variety of endocrine and exocrine glands including breast, pancreas, and prostate, and in the nervous system.

Obstetricians and pediatricians in daily practice will find here the answersand explanations they need concerning the major problem of perinatal asphyxia. Leading experts in pediatrics, obstetrics and neurophysiology havecome together to produce a single sourcebook covering all aspects of thesubject. Biochemical mechanisms and clinical aspects of perinatal asphyxia, fetal and neonatal assessment, and perinatal management are thoroughly discussed. Neurodevelopmental outcome is another important issue addressed. In light of newer technologies, the prognosis of infants suffering from asphyxia is examined. Many figures and typicalcases are provided, making the book easy to use and providing quick access to solutions. The reader can easily identify a problem in the fetus and its subsequent development. With such knowledge, the improved managementof perinatal asphyxia is made possible.

Over the past ten years, carbon dioxide laser surgery has made impressive strides and is now applied to every field of surgery without exception. It is the intention of this book to record the work done in this field in the Department of Plastic and Maxillofacial Surgery of the Beilinson Medical Center and Tel Aviv University Medical School, Israel, as well as that performed in association with other depart ments. In this context, one feels that it is incumbent upon one to acknowledge the cooperation of the medical and paramedical staff of the Department of Plastic and Maxillofacial Surgery of the Beilinson Medical Center, as well as that of Prof. Yehuda Shindel and Dr. Daniel Katenelson of the Department of Ear, Nose and Throat, Dr. Y ona Tadir of the Department of Obstetrics and Gynecology and Dr. Itamar Kott of the Department of General Surgery. I should like to make special mention of Dr. Ralph Ger of New York, who worked with me on the original clinical trials, and the engineer Uzi Sharon, who developed the Sharplan Laser with me. The progress of Laser Surgery is well demonstrated by the participation in the four meetings of the International Society for Laser Surgery, the first of which was held in Tel Aviv in 1975 with an attendance of 65 and the last in Tokyo in 1981 with an attendance of 1200.

Despite a plethora of theories, premenstrual syndrome (PMS) has remained an enigma. There has persisted in the literature a constant conflict as to the existence of the syndrome, a question as to whether it is one syndrome or several, and a debate as to whether the origin is psychic, somatic, or both. Advances in endocrinology, specifically in radioligand assays, allowing for accurate hormone measurements, have precipitated a more scientific evaluation of PMS in recent years. Nonetheless, diffi culties have persisted in accumulating well-documented data because of the protean nature of the syndrome. Indeed, even at this time, the question of what requires measurement during the follicular phase of the cycle and the premenstrual phase remains unresolved, and is difficult to place in perspective. In view of the persisting conflict between the organic and the psychological schools of thought, we, the editors of this book, considered the Sixth International Congress of Psychosomatic Obstetrics and Gynecology to be an ideal venue for a workshop in which both parties could be encouraged to participate. Towards this end, the organizing committee of the Inter national Society of Psychosomatic Obstetrics and Gynecology (ISPOG) was approached, and their response was extremely encouraging. In this respect, we wish to record our thanks to the Scientific Committee oflSOPG for allowing this workshop to be organized under their auspices, but totally under our direction. We, in turn, stand responsible for the format and content of the workshop."

The commonest cause of blindness in young and middle-aged people in the Western world is diabetes mellitus. Although the mechanism underlying diabetic retinopathy is still not understood, the technology to reduce its progress exists, provided treatment is given at the appropriate time. Doctors caring for patients with diabetes should be familiar with all aspects of diabetic retinopathy as well as the other ocular complications of diabetes. They also need a basic knowledge of the special techniques used in the diagnosis and treatment of diabetic eye disease (fundus fluorescein angiography, retinal photocoagulation, vitrectomy) and to understand how these procedures affect the diabetic patient in terms of limitation of activities and time off work. To ensure the most efficient use of ophthalmic services a clear plan of referral to ophthalmologists is required. These are the concepts on which this guide is based, compiled by an ophthalmologist involved in the treatment of diabetic eye disease and a physician with a special interest in diabetes. In addition to doctors involved in the management of diabetic patients, this guide may be of value to ophthalmic opticians, medical students and nurses as a self-instruction manual. ' 7 1 Examination of the Eye Testing visual acuity Using the ophthalmoscope The normal fundus The abnormal fundus Recording the findings 9 TESTING VISUAL ACUITY Method Test one eye at a time. Test distant visual acuity. Correct the refractive error if the visual acuity is worse than 6/6.

These four volumes comprlslng "GnRH Analogues in Cancer and Human Reproduction" are a distillation of the presentations of the invited speakers at alandmark International Symposium bearing the same name, organized by one of us (B. L. ) and held in Geneva, Switzerland in February 1988. lhe Symposium was truly interdisciplinary spanning gonadal hormone dependent disease including various forms of cancer and ranging to control of fertility, both pro- and conception. The international flavor can be caught from the 480 participants and 259 contributors drawn from 14 countries. The Symposium, and therefore this book, would not have been possible without the backing of lhe International CommitLee for Research in Reproduction and the sponsorship of the International Society of Gynecologic Endocrinology, The Swiss Society of Fertility and Sterility, lhe University of Geneva School of Medicine, The Swiss Society of Endocrinology and The US ~oundation for Studies in Reproduction Inc. , and help from the World Health Organizatlon. B. H. Vickery B. Lunenfeld June 1989 x~i LIST OF CONTRIBUTORS TO THE SERIES A. Abbondante H. Bartermann First Institute of Obstetrics and Urologische Universitatsklinik Kiel Gynecology Arnold-Heller Strasse 7 University "La Sapienza" 0-2300 Kiel 1, FRG Rome,ltaly M. Bartholomew P. Abel Department of Medicine/Endoerinology Department of Urology MUton S. Hershey Medical Center Hammersmith Hospital Pennsylvania State University DuCaneRoad PO Box 850, Hershey, PA 17033, USA London W12 OHS, UK D. Beck Departments of Obstetrics and H.

Almost all known tumors and tumor-like conditions of the fe- male lower genital tract are classified in this complete mo- nograph on the subject. Clinical features, treatment and prognosis ar included, making this book a practical refe- rence for the busy clinician.

We often hear physicians, health care professionals, poli ticians, and patient advocates that "nothing has happened in the treatment of breast cancer," since patients with breast cancer, the most frequent neoplastic condition in women in industrialized countries, are continuing to suffer relapse and succumb to this dreadful disease This negativistic attitude does not seem to be justified, but, why is the transmission of clinical trial results into general practice, and with it progress, such a slow process? After many decades of frustrating stagnation of long-term survival expectations, in all stages of early, oper/lble breast cancer treated only by surgery and locoregional radio therapy, adjuvant systemic therapy (chemo- as well as endocrine treatments) clearly showed to significantly benefit in terms of disease-free and overall survival. This evolution has been extensively expounded on by the Worldwide Oxford Overview and the Expert Consensus Panel at the fourth International Conference 'on Adjuvant Therapy of Primary Breast Cancer in St. Gallen (Early Breast Cancer Trialists' Collaborative Group 1992; Glick et al. 1992). What has happened since then? During the past 3-5 years, several new concepts and treatment strategies have emerged and have been studied in various major breast cancer groups and treatment centers worldwide. Some of these can already be considered to assist in the primary treatment of operable breast cancer today, while others are . still undergoing clini, cal trials for better definition of their practical usefulness."

ABOUT THE SUBJECT MATTER Adolescence is a time of significant change. The adolescent era spans the interval between childhood and adulthood. It is a time of physical, social, and even emotional upheaval. During this relatively brief period of time not only does physical growth accelerate but, of more significance in the biology of any species, the individual attains reproductive maturity. Within this time frame, the human being acquires the capacity to procreate and perpetuate our species. From a reproductive standpoint, throughout adeolescence the individual is being prepared for perhaps what might be considered the most important function an organism has during his/her brief sojourn on earth, namely to endow successor(s) with a minute quan tity of DNA to enable continuation of its form of life. The interlude be tween childhood and adulthood is not always socially or emotionally sim ple. The anatomic and physiologic modifications that come to pass during adolescence are not necessarily paralleled by a capacity to assume the societal responsibilities associated with reproductive maturity. Although the physiologic changes normally proceed in a predetermined fashion, adaptation to a changing role is a far more trying process. Accustomed to living in a child's world, the subject of adolescent change requires considerable time and understanding to facilitate exis tence in the adult world. The early stages of sexual awareness, for ex ample, are generally extremely confusing and, as evidenced by the in ordinately high frequency of teenage pregnancy and sexually transmitted diseases, can be extraordinarily dangerous."

This book is based on the 20th Study Group of the Royal College of Obstetricians and Gynaecologists, which concerned the important topic of fetal growth. Basic scientific and both obstetric and paediatric aspects of the subject were addressed in contributions from many different disciplines. The deliberations covered the broad topics of normal fetal growth, fetal overgrowth and fetal undergrowth. Clinical implications of these entities, especially fetal undergrowth, played a large part in the proceedings as dictated by clinical concerns. Definitions, epidemiology, aetiology and screening were covered, as were technological developments, with special reference to blood flow and volume flow measurements, both fetal and placental. Other aspects of clinical fetal monitoring, including fetal activity measurements, and biophysical evaluation were rationalised and placed in context, and the important newly emerging areas of cordocentesis and therapy in IUGR addressed. Finally, neonatal management of the SGA baby, mortality and long-term morbidity were discussed.The formal papers presented by the members of the Study Group are given together with edited versions of the ensuing discussions and the Group's conclusions.

Most textbooks are cumbersome to carry, expensive to buy, difficult to read, and boring. They have no plot, no characterization, no suspense, no climax. What they have are facts. If Dragnet's Sgt. Friday were Scientist Friday, the script wouldn't be much different "just the facts, ma'am." Students can't escape textbooks. But like death and taxes, they are necessary evils. of old ideas makes room for new ones. Death makes room for new people and the death Taxes are the dues we pay to live in a country. Everybody gets stuck with paying some kind of dues and students are no exception. Students pay dues in the form of tuition to listen to professors lecture, and they also pay dues in what a former governor of California called' 'psychic bucks" -time, concentration, independent study, reading textbooks like this one-to come up with the correct answers to exam questions. Textbooks on economics will tell you about where our tuition bucks come from. This book is about where our psychic bucks come from and the forces that can bankrupt our psychic nest eggs."

The state of health care is reflected by perinatal and neonatal morbidity and mortality as well as by the frequencies of long-term neurologic and developmental disorders. Many factors, some without immediately rec ognizable significance to childbearing and many still unknown, undoubt edly contribute beneficially or adversely to the outcome of pregnancy. Knowledge concerning the impact of such factors on the fetus and sur viving infant is critical. Confounding analyses of pregnancy outcome, especially these past two or three decades, are the effects of newly un dertaken invasive or inactive therapeutic approaches coupled with the advent of high technology. Many innovations have been introduced with out serious efforts to evaluate their impact prospectively and objectively. The consequences of therapeutic misadventures characterized the past; it seems they have been replaced to a degree by some of the complications of applied technology. Examples abound: after overuse of oxygen was recognized to cause retrolental fibroplasia, its restriction led to an in crease in both neonatal death rates and neurologic damage in surviving infants. Administration of vitamin K to prevent neonatal hemorrhagic disease, particularly when given in what we now know as excessive dos age, occasionally resulted in kernicterus. Prophylactic sulfonamide use had a similar end result. More recent is the observation of bronchopul monary dysplasia as a complication of respirator therapy for hyaline membrane disease."

The European School of Oncology came into existence to respond to a need for informa tion, education and training in the field of the diagnosis and treatment of cancer. There are two main reasons why such an initiative was considered necessary. Firstly, the teaching of oncology requires a rigorously multidisciplinary approach which is difficult for the Univer sities to put into practice since their system is mainly disciplinary orientated. Secondly, the rate of technological development that impinges on the diagnosis and treatment of cancer has been so rapid that it is not an easy task for medical faculties to adapt their curricula flexibly. With its residential courses for organ pathologies and the seminars on new techniques (laser, monoclonal antibodies, imaging techniques etc.) or on the principal therapeutic controversies (conservative or mutilating surgery, primary or adjuvant chemotherapy, radiotherapy alone or integrated), it is the ambition of the European School of Oncology to fill a cultural and scientific gap and, thereby, create a bridge between the University and Industry and between these two and daily medical practice. One of the more recent initiatives of ESO has been the institution of permanent study groups, also called task forces, where a limited number of leading experts are invited to meet once a year with the aim of defining the state of the art and possibly reaching a consensus on future developments in specific fields of oncology.

Changing approaches to diagnosis and clinical management of the uterus are comprehensively examined in this book. It gives a concise update of new concepts in physiology and pathology and their application in clinical practice. The book is designed especially for the gynecologist actively involved in patient care. Topics discussed include the pathophysiology of diethylstilbestrol (DES) changes, the immunology of the uterus, papillomaviruses and cervical neoplasia, endocervical carcinoma, mesenchymal tumors and diagnostic procedures such as colposcopy of the cervix, hysterosalpingography, and magnetic resonance imaging. The status of contemporary management is presented for hysteroscopy and hysteroscopic surgery, the congenital absence of the uterus and vagina, anovulatory dysfunctional uterine bleeding of the adolescent, uterine leiomyomata, genital prolapse, endometrial adenocarcinoma and childhood rhabdomyosarcoma of the vagina and uterus.

an adequate oxygen supply is vital for the undisturbed development of the fetus and its functions. This book gives a synopsis of the ruling influence that oxygen has in multiple regulation sytems in the mother and especially in the fetus. The authors consider oxygen as a manipulated variable or as a corrective element during normal pregnancy, during delivery and during acute and chronic oxygen deficiency. Furthermore, they deal with the consequences that oxygen deficiency has on the fetus.

Congenital adrenal hyperplasia (CAH) consists of a group of disorders of adrenal steroidogenesis. Each disorder results from an inherited deficiency of one of the several enzymes necessary for normal steroid synthesis. The different enzyme deficiencies produce characteristic patterns of hormonal abnormalities; the clinical symptoms of the different forms of CAH depend on the particular hormones that are deficient or that are produced in excess. The earliest documented description of CAH was by DeCrecchio in 1865 (DeCrecchio 1865). This Neapolitan anatomist described a cadaver having a penis with first degree hypospadias but no externally palpable gonads. Dis- section revealed a vagina, uterus, fallopian tubes, ovaries, and markedly enlarged adrenals. It is interesting that the subject suffered a confusion of sex assignment, being declared a female at birth and a male 4 years later. He conducted himself as a male sexually and socially. Since the original descrip- tion of this case, investigators have unravelled the pathophysiology of the inborn errors of steroidogenesis. 1 Steroidogenesis and Enzymatic Conversions of Adrenal Steroid Hormones A. Steroidogenesis The adrenal synthesizes three main classes of hormones: mineralocorticoids (17-deoxy pathway), glucocorticoids (17-hydroxy pathway), and sex steroids.

Medical ethics is a difficult and controversial field and that part of it dealing with reproductive medicine is no exception. Our first conference on philosophical ethics in reproductive medicine (PERM 1) in 1988 discussed many of the controversies in this field. The acclaim it received encouraged us to organise PERM 2 but choosing a relevant and topical programme was a clairvoyant challenge in its own right. Since PERM 1 we have seen a number of developments, in the UK and internationally, that have thrown the problems that society must face into sharp relief. Drawing on the expertise of contributors from science, many medical specialities, philosophy, theology and economics, we have sought to address the issues raised by these new developments, as well as a number of long-standing issues that remain as contentious as ever, but of undiminished significance. On the scientific front, the long-predicted technique of embryo biopsy and diagnosis is now a reality. This has prompted the inclusion of some of the topics addressed by this second conference.

Sexual medicine is an interdisciplinary subject. Special knowledge of normal and disturbed sexuality is expected of general practitioners, gynecologists, dermato logists, urologists, specialists in internal medicine, neurologists, psychiatrists, and psychotherapists. Sexual dysfunctions may occur in connection with organic lesions or as psychosomatic phenomena. They are brought to the practicing physician's attention by the patient either directly or in the form of factitious symptoms. The disturbed sexual function generally causes suffering and so motivates the patient to consult a physician. Psychosomatic aspects are thus very much to the fore. In a significant number of cases, however the disturbances stem from a physical-functional handicap which not only affects the patient's general personality but also has a direct adverse effect on sexual function. The physical defect leads to disturbances of the body-image, and so can cause impairments in the sexual sphere both directly and indirectly. The diseases which result in sexual handicap and which can be treated by reconstructive surgery were examined and discussed at an international satellite symposium of experts on the occasion of the 8 th World Congress for Sexology in June 1987. The papers presented at this symposium have been collected and edited in this volume."

The Third International Copenhagen Symposium on Detection of Breast Cancer afforded a further opportunity for scientists from all over the world to come together and present important papers con cerning breast cancer and early diagnostic procedures. The Sympo sium was an opportunity to learn from extensive screening proce dures carried out at outstanding centers in the United States, Sweden, the Netherlands, and England. Furthermore, the Sympo sium dealt with new modalities such as ultrasonography, magnifi cation techniques, and magnetic resonance; and very important contributions concerning self-examination, fine needle aspiration biopsy, and radiation risks were presented. A whole section was also dedicated to the highly important cooperation between radiologist, surgeon, and pathologist. It is our sincere hope that a study of the different aspects of breast cancer presented in this volume will encourage the reader to join in the struggle against this dreadful dis ease. December 1986 S. Brunner B. Langfeldt Contents B. Nielsen Image Quality in Mammography: Physical and Technical Limitations . 1 S. A. Feig, B. M. Galkin, and H. D. Muir Clinical Considerations in Selection of Dedicated Mammography Units . . . . . . . . . . . . . . . . . . . . 15 . . . E. A. Sickles The Role of Magnification Technique in Modern Mammography . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. M. Galkin, S. A. Feig, P. Frasca, H. D. Muir, and R. Z. Soriano Imaging Capabilities and Dose Considerations of Different Mammographic Units . . . . . . . . . . . . . . . . . . 25 . . . E. A. Sickles Computed Tomography Scanning, Transillumination, and Magnetic Resonance Imaging of the Breast . . . . . . . . . . . 31 A. G. Haus Recent Trends in Screen-Film Mammography: Technical Factors and Radiation Dose . . . . . . . . . ."

The ultimate "consumer" of the data presented at conferences on the primary treatment of operable breast cancer is the patient, and when, as in this disease, the benefits of therapy are relatively mod est, the availability and interpretation of the data from trials be comes an issue of primary importance. The effects of present treat ment are in fact such that more patients relapse despite therapy than are estimated to benefit from it. It is, therefore, extremely dif ficult for the physician to recommend unequivocally one particular adjuvant treatment modality for the vast population of women with breast cancer. The interpretation of results from clinical research-oriented pro grams is constantly applied, however, in the treatment of breast cancer patients outside of clinical trials. From presented or publish ed data, many physicians extrapolate indications for the use of a given treatment regimen for their patients, perceiving it as the "best available therapy. " It is essential that the "best available therapy" be selected individually for each patient. However, considering the modest effect of treatment upon outcome, it is imperative that those who provide the data - those who are involved in both pa tient care and clinical research - make it known that the best cur rent treatment for the population of breast cancer patients is avail able within the framework of clinical trials. In this way not only present-day patients but also future ones will derive the greatest benefit.

Perinatal medicine, which is concerned with the problems of the fetus and newborn, has rapidly developed in the last two decades as an important and challenging specialty. Rapid advances in the field, coupled with tech nological advances, now are making survival of infants with weights as low as 500 grams possible. Ventilator care for severe respiratory problems is on the verge of being replaced by surfactant replacement therapy; on the other hand, development of such technologies as extracorporeal mem brane oxygenation and jet ventilation has revolutionized the care of these sick infants. The advances taking place today in the field of perinatal medicine make periodic updates, like the one provided by this volume, a virtual necessity for clinicians and paramedical personnel alike. A distinguished group of specialists in various aspects of perinatal medicine has contributed to this book. Their wide-ranging experience and points of view should make this book a valuable reference for all physicians and allied health personnel involved in the care of the high-risk fetus and newborn. MANOHAR RATHI, M.D. Acknowledgements. I am grateful to the contributors for their cooperation in preparing the manuscripts, to my associates for their help and support, and to the publishers for their continued interest in this work. Above all, I thank Ms. Rose Aiello-Lech and Ms. MaryAnn Cichowski for their hard work in making this publication possible."

Endocrinologic investigations during pregnancy have focused in the last decades on placental hormones, the maternal endocrine system and maternal fetal interactions. Less is known about the fetus itself and the interaction of fetal hormonal response and physiological parameters. In this book physiologists, pediatricians and obstetricians active in experimental studies in both physiology and endocrinology combine both aspects of investigations. Historical remarks on the endocrine development of the fetus are followed by observations of the hormonal control of the cardiovascular system. Basic mechanisms of fetal endocrine control such as brain development, fetal growth, fetal behaviour, and thermoregulation are given particular consideration. Finally, carbohydrate metabolism and the mechanism of parturition are outlined.

I am very happy and honoured to have so many famous contrib utors from around the world presenting their knowledge and experience in this book, including Dr. Rufer who, as early as 1967, attempted to improve the pressure-volume curve of a child dying from RDS using dried surfactant from dogs; Drs. Enhorn ing and Robertson who were the first to treat rabbit fetuses with surfactant replacement and impressively demonstrated that sur factant improved lung mechanics; and Dr. Fujiwara who at the end of the 1970's had already successfully treated the first babies with surfactant replacement and published this work al ready in 1980. Thus, the idea of surfactant replacement therapy is now more or less 20 years old and almost 10 years have passed since the first publication by Dr. Fujiwara of his impressive clinical results. Up to now (September, 1988) about 2,200 babies have been treated worldwide with tracheal instillation of surfactant, with most promising results. The type of surfactant used varies from pure natural extracts from bovine or pig lungs, to surfactant extracted from human amniotic fluid, to pure phospholipids. To date, however, there is still no surfactant commercially available (except in Japan), in spite of the fact that it is urgently awaited by neonatologists and intensive care doctors throughout the world. This volume is based on the contributions presented at the international congress on Surfactant Replacement Therapy which was held in Rotterdam, The Netherlands, in November 1987."

The account of "neonatal sterilization" is the story of the advocates of direct effect of steroids on the gonads and those who believed in the indirect influence, mediated through the hypothalamus and/or the pituitary gland. As often happens in biology, both convictions represent the same image seen from different perspectives. Prof DC Johnson (Kansas City, KS) reminisced the beginning of the story in a letter to me. I am paraphrasing parts of the letter with his permission. "As a starting point we could pick the life-long research of Emil Steinach ... " Steinach recognized the influence of testes on the develop ment of accessory sex organs in 1894, described virilization of females and feminization of males in 1913, and identified the controlling influence of the hypophysis on the gonads in 1928. He reviewed his work in a book Sex and Life, Forty Years of Biological and Medical Experience (E Steinach and L Loebe!; Faber and Faber, London, 1940). He got on the wrong road in later years and that is the reason everybody seems to have forgotten him. He presented his hypothesis that estrogen has a direct effect upon the testes, i. e. hormone antagonism, at the 1st International Congress on Sex Research in 1926.

The term polycystic ovary syndrome (peOS) is meant to describe a clinical endocrinopathy characterized by menstrual irregularity and evidence of hyperandrogenism. While recognized since the 1800s, a clinical composite was not constructed until 1935 when Stein and Leventhal reported their findings of seven women with infertility, menstrual dysfunction, hirsutism, and enlarged ovaries. Notably, the ovaries contained numerous multiple cysts and the ovarian capsule was thickened. At the time, this preciseness of definition was sufficient to entitle the entity Stein-Leventhal syndrome. Subsequently, over the intervening years as investigators attempted to un ravel the pathophysiology and genesis of this disorder and the number of reported studies increased, there ensued a gradual and distinct terminologic conversion to polycystic ovary syndrome, which, whether intentional or not, connoted a less well-defined condition. Perhaps this is appropriately so, given the seemingly broadening spectrum of clinical presentations and the continuing debate over what constitutes peos. The expansive new knowledge about peos was discussed to a significant degree at an international symposium organized by Serono Symposia USA and held in Boston in the late spring of 1995. Ovarian physiology, including the fate of the follicular unit, was a central focus with several presentations on the genesis, growth, and death of ovarian cellular components. A discus sion of the regulation of ovarian cell function was also highlighted and comprised a major portion of the program."