For many years now, our understanding of the somatotrophic and reproduc tive axes has evolved essentially independently, both fields of study reaching a highly advanced, although far from complete, level of under standing. Along the way, however, it became apparent that in some circumstances the reproductive and somatotrophic axes may be inter dependent. Inklings to this effect were at times feeble and at other times more convincing. Among those inklings are the clinical recognition by pediatric endocrinologists of the apparent association between isolated GH deficiency and delayed puberty, as well as of the apparent permissive, pUberty-promoting property of GH. Equally important is a body of experi mental studies establishing the ovary of multiple species as a site of GH reception and action. Arguing against an essential role for GH in the reproductive process is the observation that individuals who have GH resistance of the Laron variety are fertile arid that isolated GH deficiency does not constitute an absolute barrier to the attainment of sexual maturation and fertility. The intraovarian insulin-like growth factor (IGF) hypothesis proposes that IGFs may serve as amplifiers of gonadotropin action. Although the dependence of intraovarian IGFs on systemic GH action has never been unequivocally demonstrated, that leap of faith has often been made. The intraovarian IGF hypothesis serves as the rationale for the adjunctive use of GH in the induction of ovulation."

Thoroughly illustrated, this second edition provides the primary care physician with detailed information on the most commonly encountered clinical situations and the most frequently asked questions. The chapters address everything the primary care physician will regularly face and will need to know about the breast, pregnancy, sexually transmitted diseases, contraception, infertility, gynecologic cancers, urogynecology and gynecology.

The importance of osteoporosis in the United Kingdom as a cause of death and disability is now well recognised. There are in excess of 200,000 osteoporotic-related fractures in the UK per annum asso ciated with an estimated cost of GBP942,000,000. Following hip fracture it is known that about 50% of patients are unable to live indepen dently and about 20% of such patients die within the first 6 months. These figures, compelling as they are, reflect poorly on current medical practices which manifestly have failed to identify patients with low bone density at risk of fracture. The hope is that the techni cal advances which have enabled bone mineral density, and other allied indices, to be measured with high precision and accuracy offers the chance of identifying patients at risk of fracture and guiding the clinician to make treatment decisions which may reduce the patients' risk of fracture. In the UK, services for identifying patients at risk of fracture are still in their infancy and are not uniformly available throughout the country. This situation is, however, likely to improve particularly fol lowing the publication of the Royal College of Physicians report "Osteoporosis -clinical guidelines for prevention and treatment" and the recognition in "Our Healthier Nation" that osteoporosis pre vention should be included as a target to achieve a reduction of 20% in accidents by 2010.

Since its inception in 1976, the overall goal of the Ovarian Workshop has been to bring together biologists from various disciplines so that they may collectively achieve a better understanding of the latest developments and define important problems in ovarian physiology. The Ovarian Workshop, which was pioneered by Dr. A. Rees Midgley, has developed into a major biennial meeting for investigators in the ovarian field. Largely as a consequence of advances in technology, especially in mo- lecular biology, progress in the area of gene expression and signal transduc- tion has been rapid. The Eighth Ovarian Workshop focused on two major topics: (1) the expression of hormonally and nonhormonally controlled genes involved in the functional and morphological differentiation of the cells forming the ovary and (2) the signaling mechanisms by which endogenous and exogenous hormones and cytokines affect ovarian differentiation and steroidogenesis. The Eighth Ovarian Workshop, held on the campus of Maryville College in Maryville, Tennessee, July 12 to 14, 1990, was again generously funded and coordinated by Serono Symposia, USA. I would especially like to thank Dr. Lisa Kern of Serono for her expert help in organizing this meeting. The board of directors of the Eighth Ovarian Workshop consisted of Drs. Eli Adashi, JoAnne Fortune, Anne Hirshfield, Aaron Hsueh, Julia Lobotsky, Gordon Niswender, David W. Schomberg, Richard Stouffer, and Jerry Strauss. Their valuable advice and the important roles they played in the planning of the scientific program are gratefully acknowledged.

practitioner up to date on the various aspects of conditions and diseases considered to be sexually transmitted. REFERENCES 1. Crissey JT, Denenholz DA: Development of the modern forms and concepts of syphilis. Clin Dermatol, 2(1):1-10, 1984. 2. Panconesi E, Mazzi M: The day syphilis came. Int 1 Dermatol, 23:284-286, 1984. 3. Washington AE, Johnson RE, Sanders LL: Chlamydia trachomatis infections in the United States: What are they costing us? lAMA, 257:2070-2074, 1987. 4. Bulkley LD: Syphilis in the Innocent. New York: Bailey and Fairchild, 1894. 5. Syphilis: Major perinatal killer. Med World Trib, 28(16):2, 1987. 6. Renshaw DC: Management of impotence. I. Psychological considerations. Clin Therap, 9:142-148,1987. Acknowledgments. We are very grateful to our teachers for the stimulation they provided in our studies of dermatology and sexually transmitted diseases. We partic ularly acknowledge the impetus given by Herman Beerman, M.D., Emeritus Professor of Dermatology, University of Pennsylvania School of Medicine, Philadel phia. Our office staffs have been particularly helpful, and we would like to recognize the contributions of Mrs. Carmela Ciferni. Lastly, this book was conceived through the inspiration of Dr. Jerry Stone, late Senior Medical Editor of Springer-Verlag, New York. Philadelphia, Pennsylvania LAWRENCE CHARLES PARISH Vienna, Austria FRIEDRICH GSCHNAIT Contents Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Xl . . . . . . . . . . . . . . . What are Sexually Transmitted Diseases? Chapter 1 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . LOIS Y. MATSUOKA Chapter 2 Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 . . . . . . . . . . . . HARRY L. ARNOLD, JR. Diseases Chapter 3 Syphilis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 . . . . . . . . . . . . . JOHN THORNE CRISSEY Chapter 4 Endemic Treponematoses . . . . . . . . . . .. . . . . . . . . . . . . . . . 32 . . ."

Intrauterine Growth Restriction: Aetiology and Management will be the first book to focus exclusively on this extremely important and common complication of pregnancy. There have been many recent developments in our understanding of the aetiology and pathogenesis of the condition as well as in screening, monitoring and therapy. This book is unique in that it covers both the aetiology and pathogenesis as well as clinical management and also includes sections on definitions and potential future advances. Every aspect is covered by an international expert which will provide the reader with a valuable insight into this condition.

In the last few years rapid advances have been made in reproductive medicine, making it necessary for those involved to regularly update their knowledge. The purpose of this book is to describe the state of the art in this field, making it possible for the reader to gain an orientation among all the diagnostic and therapeutic potentials of modern reproductive medicine in order to advise patients fully. Chapters from the fields of gynecology, and reproductive medicine in a specific sense provide knowledge about these subjects. Authors of international standing have contributed chapters on their specialties. These chapters together form a book describing the state of the art in the diagnosis and therapy of sterility in gynecology and andrology.

The purpose of this series of volumes is to present a comprehensive view of the complications that result from the use of acceptable diagnostic and thera peutic procedures. Individual volumes will deal with iatrogenic complications involving (1) the alimentary system, (2) the urinary system, (3) the respiratory and cardiac systems, (4) the skeletal system and (5) the pediatric patient. The term iatrogenic, derived from two Greek words, means physician-in duced. Originally, it applied only to psychiatric disorders generated in the patient by autosuggestion, based on misinterpretation of the doctor's attitude and comments. As clinically used, it now pertains to the inadvertent side effects and complications created in the course of diagnosis and treatment. The classic categories of disease have included: (1) congenital and developmen tal, (2) traumatic, (3) infectious and inflammatory, (4) metabolic, (5) neoplastic, and (6) degenerative. To these must be added, however, iatrogenic disorders a major, although generally unacknowledged, source of illness. While great advances in medical care in both diagnosis and therapy have been accomplished in the past few decades, many are at times associated with certain side-effects and risks which may result in distress equal to or greater than the basic condi tion. Iatrogenic complications, which may be referred to as "diseases of medical progress," have become a new dimension in the causation of human disease."

The concept of the foeto-placental unit as an integrated endocrine organ has been defined recently by many in vivo studies at the 17th- 20th week of gestation. A functioning foeto-placental unit is necessary for most of the increased oestrogen production of pregnancy and for the provision of glucocorticoids and aldosterone to the foetus. Neither the foetus nor the placenta alone have the necessary enzyme systems for the synthesis of these groups of steroids. However, when the foetus and placenta function as a unit, all of the enzyme systems are present for the synthesis of these steroids from circulating cholesterol. The placenta, but not the mid-gestation foetal adrenal, can synthesize physiologically significant amounts of pregnenolone from circulating cholesterol. Part of the pregnenolone is converted to progesterone in the placenta by the 3 -HSD system (absent in the foetus). The progesterone is transferred to the foetus where it is transformed by C-II, C-17, C-18 and C-21 hydroxylases (all absent in the placenta) to cortisol, corticosterone and aldosterone. Pregnenolone transferred from the placenta to the foetus undergoes 171X-hydroxylation, side chain splitting and sulfurylation (absent in the placenta) and is converted to DHAS. The DHAS may undergo 161X-hydroxylation (absent in the placenta) in the foetal liver and be transported to the placenta as 161X-OH-DHAS. There it is subjected to a neutral steroid sulfatase (absent in the foetus) and is converted to oestriol by action of the 3 -HSD system and the aromatizing enzyme system."

The birth of a baby is the culmination of months of anticipation and plan ning. Most often, mother and infant are healthy and readily able to estab lish close contact-a bond. However, in some situations either mother or baby or both present complications. The more prompt and rational the treatment, the sooner the normal parent-infant relationship will commence. This book is devoted exclusively to the first days following birth. In its 15 chapters, postpartum and postnatal physiology and pathophy i: .;logy are reviewed by 18 specialists. Normal and abnormal development of mother and child is correlated with proven means of clinical management. Chapters 1 through 3 cover maternal postpartum developments and complications. Chapter 4 stresses the importance of a normal parent newborn relationship, a concept of increasing concern in modern society. The following ten chapters discuss neonatal physiology and pathophysi ology; the effects of obstetric anesthesia on infant behavior, pulmonary function measurements in the postnatal period and treatment of the sick newborn are discussed in detail. The final chapter reviews maternal and perinatal mortality; the data, based on extensive surveys in New York City, indicate that current management is effecting an overall decline in mortality."

Contraception is the most comprehensive exploration of the newest technologies in the area of contraception. Edited by renowned authorities Dr. Donna Shoupe and Dr. Florence Haseltine, with chapters written by leaders in the field, this book comprises the most up-to-date, practical and clinical information available and presents a thorough examination of clinical efficacy, side effects, mechanisms of action, and benefits of all types of contraception, including: - chapters on the IUD, the new subdermal implant Norplant, injectables, the diaphragm, condoms, sponge, female sterilization, vasectomy, and more - discussions of cutting edge contraceptive technologies, including the new progestin oral contraceptive pills, contraceptive vaginal rings, and RU 486, - an important chapter on AIDS and contraception. This book will serve as an invaluable reference providing useful, instructive background information and pertinent clinical applications for the physician, resident, and researcher. At such an exciting time for contraceptive technology, no one in the field can afford to be without this text.

This book is a compilation of edited papers which were presented at the XIth World Congress of Fertility and Sterility held in June 1983 in Dublin, Ireland. Although it has long been known that male factors are responsible in at least 30% of infertile couples only recently have concerted efforts been made on the part of urologists, gynaecologists and basic scientists to identify these factors more precisely. The nature of spermatogenesis is complex but application of various scientific methods have at last opened up new and promising approaches to our understanding of this subject. Clinical results however have been depressing; the majority of treatments lack realistic evaluation and are initiated in hope rather than with a sound scientific basis. We anticipate that this volume will in some small way correct these deficiencies. The papers have been grouped into related topics. The first section deals with the evaluation of the spermatozoa and includes a critical assessment of the recently introduced zona-free hamster egg test of sperm function. Further sections include the biochemistry of gonadal function and the immunology of male reproduction; most papers are concerned with studies in the human. The clinical sections cover medical and surgical approaches to treatment and the final section deals with various aspects of AID practice.

The VIIIth Annual International Spring Symposium on Health Sciences held at the George Washington University School of Medicine in Washington, D.C., attracted over three hun dred fifty scientists from twenty-five countries. The leading scientific experts in the field reported on recent biomedical advances in aging. They provided an up-to-date account of the molecular, genetic, nutritional, and immunological mechanisms associated with the aging process and approaches to intervention and treatment of the major disorders associated with the aging process, including Alzheimer's disease. A unique aspect of this meeting was a concurrent one-day hearing of the U.S. Senate Sub-Committee on Aging, organized by the Alliance for Aging Research. The theme for the hearing was "Advances in Aging Research." Seven scientists attending our aging sym posium were asked to testify. They were Drs. Carl Cotman (University of California-Irvine), Trudy Bush (Johns Hopkins University), Takashi Makinodan (University of California-Los Angeles), William Ershler (University of Wisconsin-Madison), Gino Doria (ENEA, Rome), Mr. Dan Perry (Director of the Alliance for Aging Research), and myself."

These four volumes comprlslng "GnRH Analogues in Cancer and Human Reproduction" are a distillation of the presentations of the invited speakers at a landmark International Symposium bearing the same name, organized by one of us (B. L. ) and held in Geneva, SwitLerland in February 1988. The 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 The International Commitlee for Research in Reproduction and the sponsorship of the International Society of Gynecologic Endocrinology, The Swiss Society of fertility and Sterility, The University of Geneva School of Medicine, The Swiss Society of Endocrinology and The US foundation for Studies in Reproduction Inc. , and help from the World Health Organization. B. H. Vickery B. Lunenfeld June 1989 xiii 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" D-2300 Kiel 1, FRG Rome, Italy M. Bartholomew P. Abel Department of Medicine/Endocrinology Department of Urology Milton S. Hershey Medical Center Hammersmith Hospital Pennsylvania State University DuCaneRoad PO Box 850, Hershey, PA 17033, USA London W12 OHS, UK D. Beck H.

Infectious diseases remain a major problem for physicians and other health professionals dealing with problems of the reproductive system. Accordingly, this two-volume comprehensive presentation of infectious diseases involving the male and female reproductive systems promises to be a major contribution in this field and to fill a much-needed vacuum. During the past three decades, the introduction of antimicrobial therapy has dramatically altered both the clinical presentation and the therapeutic approaches employed in dealing with the traditional infections of the repro ductive system. In addition, the changing demographics of infectious problems in the industrial countries and the developing world have been a source of concern. A good deal of important information on this topic is included in this series. In recent years, considerable attention has been given to the role of Myco plasma and Chlamydia in both male and female infertility and the problems related to genital herpes and human papilloma virus infections. Current clinical information is included on these infections as well as on newer aspects of diagnosis, such as the use of laparoscopy in the diagnosis and treatment of pelvic inflammatory disease. Also addressed is new information regarding the role of actinomycosis in pelvic infections; current problems such as toxic shock syndrome and acquired immune deficiency syndrome (AIDS) are reviewed as well. New concepts are included in these volumes to complement the clinical information. The attachment of microbial organisms to sperm may help to explain access of these and other organisms to the upper female genital tract."

This RRCR-conference-volume marks "number six" in a 20-year evolution of international conferences on the adjuvant therapy of primary breast cancer. Starting in 1978, a handful of some 80 en thusiastic breast cancer surgeons and oncologists, met in a se cluded mountain resort near st. Gallen in Eastern Switzerland, to exchange their early data of some pioneer trials on adjuvant sys temic therapy of early breast cancer, and to correlate their future research efforts to overcome the frustrating prognostic stagna tion of this dominant neoplastic disease in Western females dur ing the past decades. Repeated every 3-4 years, these St. Gallen International Conferences on Adjuvant Therapy of Primary Breast Cancer have continuously grown in numbers of partici pants and in normative, therapeutic influence by being published in major oncology journals 1-3], the last (6th) conference hav ing taken place from February 25-28, 1998 with more than 1800 attendees from over 50 countries worldwide. What is the fascination of adjuvant therapy in primary (early) breast cancer, and what has changed, during the last 3 years since March 1995, to justify another international gathering of this size, and of the world's leading experts in the field? There is no question, that providing even more effective care and designing appropriate recommendations for the multitudes of patients with so-called early breast cancer or at high risk of developing the disease, remain highly important public health goals."

One of the first applications of lasers was for surgery on the retina of the eye. That, and the evident analogy to the old dreams of powerful heat rays, led many to predict that lasers would quickly be used for all kinds of cutting and welding, including surgical applications. It was soon apparent that laser sur gery could be performed in ways that caused little bleeding. Nevertheless, other surgical applications have been slower to arrive. One difficulty has been the enormous range of possibilities provided by the many different kinds of lasers. Infrared, visible, and ultraviolet light beams each interact very differently with human tissues. Light pulses of enor mously great peak powers became available from lasers, but their effects dif fered in surprising ways from those obtained with continuous beams. That provided both opportunities (i.e., treating or removing a very thin surface layer without affecting the underlying tissue) and problems with undesired side effects. Moreover, techniques were needed to deliver a precisely con trolled amount of energy just where it was desired. Lasers also had to be engineered and manufactured with the desired power levels and a high reliability."

This book was written to provide a clear and systematic sum mary of the principles of gynaecology in synoptic form. It is part of a three volume series, the first two volumes covering topics in undergraduate obstetricE and neonatal medicine respectively. Where appropriate, fundamentals of related anatomy and physiology are also covered. It is primarily directed at under graduate medical students and midwives, but material useful as reference to doctors revising for further qualifications has been included. Although much of the content is organized in the form of lists, this book differs from the usual 'list' book in that cover age is full and systematic. Thus the text has been organized into the following subheadings, where appropriate: Definitions, Aetiology, Pathophysiology, Clinical features, Differential Diag nosis, Investigations, Treatment, and Prognosis. To avoid rep etition, certain clinical areas including ectopic pregnancy and abortion which have been covered in the earlier volumes are not included. Certain useful diagnostic lists are also provided, and, in pre paring the book, previous examination papers of the Univer sities of Oxford, Cambridge and London, as well as of the Central Midwives Board, were consulted. Illustrations have been specially prepared in the form of explanatory line drawings that are simple, and easy to memorize and reproduce. Although drug dosages were checked with care before going to press, changes in medical practice make it advisable to verify regimes and doses with the latest prescribing information and the pharmacopoeia, before use."

Having received the invitation from Springer-Verlag to produce a volume on drug-induced birth defects for the Handbook of Experimental Pharmacology, we asked ourselves what new approach could we offer that would capture the state of the science and bring a new synthesis of the information on this topic to the world's literature. We chose a three-pronged approach, centered around those particular drugs for which we have a relatively well established basis for understanding how they exert their unwanted effects on the human embryo. We then supplemented this information with a series of reviews of critical biological processes involved in the established normal developmental patterns, with emphasis on what happens to the embryo when the processes are perturbed by experimental means. Knowing that the search for mechanisms in teratology has often been inhibited by the lack of understanding of how normal development proceeds, we also included chapters describing the amazing new discoveries related to the molecular control of normal morphogenesis for several organ systems in the hope that experimental toxicologists and molecular biologists will begin to better appreciate each others questions and progress. Several times during the last two years of developing outlines, issuing invitations, reviewing chapters, and cajoling belated contributors, we have wondered whether we made the correct decision to undertake this effort.

The frontispiece, Leonardo da Vinci's drawing of the embryo in the womb, was chosen as a starting point for this book. It was Leonardo who in his notebooks and drawings combined artistic composition and accurate recording of the anatomy of the human body. Leonardo studied human anatomy in order to execute artistic drawings. His aim was to clarify form and function of human organs including reproductive organs. He followed up his extensive research with graphic representa tion and thereby initiated record keeping as a basis of scientific investigation. His records, accurate three-dimensional drawings, allowed others to reproduce his find ings and to test for correctness. Results could be updated and refined. Only after these steps can abnormalities be ascertained and defined as pathology. Though Leonardo was both artist and scientist, it is assumed that his anatomic drawings were used to improve his art, and thus scientific endeavor was at the service of his art. Anatomy, the offspring of science and art, is an integration of the two and became an accepted branch of the natural sciences. Although art and science continued to interact throughout the Renaissance, art was often placed in the service of science. In the course of history that followed, art and science in creasingly followed separate ways."

The book gives an overview of the clinical developments in the use of bisphosphonates in clinical oncology. The first part pre sents the composition, physiology, and pathophysiology of bone. Next is a section giving insight into mechanisms of bone resorp tion, bone formation, and bone remodeling, a field in which I was most influenced by O. L. M. Bijvoet and H. Fleisch. The sec ond part summarizes the pharmacological treatments for disor ders of bone remodeling. The clinical aspects of tumor-induced hypercalcemia and its management are described in detail, in cluding our first prospective randomized crossover study testing pamidronate versus mithramycin. The bisphosphonates were in troduced in clinical oncology by endocrinologists. The same was true for our institution in 1986, when P. Burckhardt proposed testing pamidronate in the above-mentioned trial in his institu tion (CHUV) and in our department. The impressive results ob tained in the hypercalcemia trial stimulated our interest, and we actively investigated the use of pamidronate to counteract osteo lytic bone destruction in cancer patients. These investigations are presented and discussed in the third part. They represent the interdisciplinary work involving many co-workers of the Depart ment of Internal Medicine C and other institutes of the Interdis ciplinary Oncology Center St. Gallen (IOSG), which I was privi leged to chair for 10 years. Initially, a pharmacokinetic study was performed in order to optimize and facilitate the administration of the drug to patients with malignant osteolytic bone disease."

G. Piekarski appears not to have been brought home to at Forty years have passed since Trussent pub- least some clinicians. Of special importance in lished an important book in the English lan- this connection are T. vaginalis and Pentatri- guage on Trichomonas vaginalis Donne and uro- chomonas hominis (Davaine), the intestinal tri- genital trichomoniasis. During the intervening chomonads of many mammalian species, in- four decades, much information has been accu- cluding humans. Some practitioners still tell mulated on trichomonads parasitic in humans their patients about the possibility of an intesti- and on the diseases they cause. In light of this, nal origin of trichomonal infection of the uro- many parasitologists and clinicians believe that the time has come for a complete review, in genital tract. book form, of various aspects of these parasites Trichomonas vaginalis infection of new- and of the trichomonad parasitemias. This need borns, infants, and young children constitutes has been further reinforced by the finding that, an interesting, although not extensively pur- despite the use of effective anti trichomonal sued, area of investigation. For hitherto incom- drugs during the past years, the prevalence of pletely understood reasons, the period of preg- human urogenital trichomoniasis, the world's nancy appears to favor the increase of most common sexually transmitted disease, has symptomatic trichomoniasis; there is, there- been increasing significantly. As might have fore, little doubt that infants can be infected been expected, therefore, discussion of various during birth.

The traditional concept of a neuroendocrine mechanism for regulation of growth hormone (GH) secretion is based in large part on the work of Roger Guillemin. The work of Dr. Guillemin, who was awarded the 1977 Nobel Prize in Physiology and Medicine, supported the view that quantita tive change in GH secretion was the net result of pituitary stimulation and inhibition by the hypothalamic neurohormones, GH releasing hormone (GHRH), and somatostatin (somatotropin release inhibiting factor; SRIF), respectively. During the 1970s, another endocrine research pioneer, Dr. Cyril Bowers, discovered that structural modification of enkephalin re sulted in a family of peptides with GH releasing properties. These com pounds, simply called GH releasing peptide (GHRP), were originally thought to mimic GHRH. However, upon subsequent investigation they were found to supplement the activity of the natural hormone through a different mechanism. Nearly two decades after their discovery, the differ ences between GHRP and GHRH have been described by many different laboratories throughout the world. The complementary GH secretagogues have different binding sites, second messengers, and effects on gene expres sion. Based on these differences, it has been suggested that expansion of the original two hormone mechanisms for GH regulation to include a third molecule may be appropriate, even though the naturally occurring ana logue of GHRP has not yet been identified. Despite our lack of knowledge concerning the natural product mimicked by GHRP, clinical development of the new family of GH secretagogues for diagnostic and therapeutic purposes has begun in earnest."

A central concept in the evolutionary theory of senescence is the idea that ageing results from life-history trade-offs. In particular, the disposable soma theory suggests that longevity is determined through the setting of longevity assurance mechanisms so as to provide an optimal compromise between investments in somatic maintenance (including stress resistance) and in reproduction. Comparative studies among mammalian species confirm that cells from long-lived species appear to have a greater intrinsic capacity to withstand stresses than cells from short-lived species. Childbearing at older ages has become increasingly common in modern societies because of demographic changes, medical progress and personal choice. While the detrimental effects of late reproduction on infant mortality and genetic diseases have been well documented, little is known about the possible postponed detrimental effects of late parenting.