Serono Symposia USA – serie

This volume contains the proceedings of the Symposium on GHRH, GH, and IGF-1: Basic and Clinical Advances, held December 9 - 12, 1993 in San Diego, California. Written and edited by eminent international experts, the papers herein cover: an overview of the physiology of GHRH-Somatostatin-GH-IGF-1 axis; the effects of recombinant human GH and/or IGF-1 in catabolic illness; contemporary issues in growth and development; the effects of rhGH and IGF-1 on intermediary and bone metabolism; and the use of GHRH, rhGH, and rhIGF-1 in aging.

The young investor with an idea has to negotiate many institutional, federal, and industrial challenges in order to get a product to market and has little knowledge of the steps in the development of new drugs, diagnostics, or devices. This volume contains the proceedings of the Symposium on Idea to Product: The Process, held in Washington D.C. from November 17 - 20, 1994. Written and edited by eminent authorities in the field, the papers herein contain timely, practical information on planning clinical research, identifying funding opportunities, details of drug development, negotiating the system, understanding the organization and function of the FDA, patenting and licensing, clinical trial development and design, and starting a medical product business. A must for those planning a career in academic medicine as well as for established academicians seeking an organized, comprehensive overview of the process.

Embryoimplantationisaremarkableandcomplexprocess. Approachesde- velopedfromthefieldsofcellanddevelopmentalbiology,immunology, andmolecularbiologyhavegreatlyenhancedourabilitytostudythe sharedaswellasuniquefeaturesofembryo-uterineinteractions. Impres- siveandcriticalgroundworkhasbeenlaidbyalargeanddedicatedarray ofendocrinologists,reproductivebiologists,andanatomists. Thesestudies havesetthestagetoutilizesensitiveandsophisticatedtechniquestode- tectandmodulateproteinandgeneexpression. Justasthesymbiosisofmother andfetusiscriticalforthemaintenanceofpregnancy,soisthesynergyamong investigatorsfrommanydisciplines,bothinbasicandclinicalarenas,keyto unravelingthemysteriesofimplantationandplacentation. Alargegroupof contributorsinthisfieldhadtheopportunitytomeetanddiscussthestateof thisartwiththesupportofSeronoSymposiaUSA,Inc. Whileitisneverpos- sibletobringtogethereveryonewhohasplayedanimportantrole,itwas, nonetheless,bothexcitingandgratifyingtohavesomanycolleaguestogether forthisevent. Inthechaptersthatfollow,thehighlightsofthismeetingarepresented assummarizedbytheindividualpresentersofsevendifferentsessions.The topichasbeenconsideredfromthebroadsocialandethicalimplications ofmoderninvitrofertilizationandassistedreproductivetechnologiesto detailedmolecularcontrolsovereventsthatoccurduringembryonicdevel- opment,uterinepreparationforimplantation,andplacentalorganogenesis. Thesechaptersdemonstratethesignificantandrapidprogressbeingmade inthisfieldofbiologyandmedicine. Atthesametime,theyshowthat muchmoreneedstobedonetounderstandandfullyappreciatethispro- cess. Lessonslearnedfromthiseffortcanbeexpectedtocontinuetopro- videinsightsintoother,relatedfields. Ofthemanycontributorstoour understandingoftheprocessofimplantation,nonehavehadalargerim- pactthanourcolleague,AllenEnders. Dr. Endershasplayedaparamount roleindevelopingthebasicunderstandingofthecellbiologicalprocesses vii VIII Preface underlyingimplantationandplacentationinmanyspecies,includinghu- mans. Hecontinuestocontributeandguidethoughtintheseareas. The participantsofthissymposiumrecognizedDr. Enders'impressivecontribu- tionsbyholdingthiseventinhishonor. DANIELD. CARSON * Contents Preface vii Contributors xiii PartI. Development and Future ofHuman In Vitro Fertilization and Embryo Implantation I.ImplantationintheHumanasViewedbyCanonLaw, CivilLaw,andNaturalReason 3 HOWARDW. JONES, JR. , RICHARDA. MCCORMICK, AND SUSAN L. CROCKIN 2. TheImpactofMaternalAgeandOvarianAge onImplantationEfficiency...12 STEVEN SPANDORFER AND ZEV ROSENWAKS Part II. CellularAspects ofImplantation 3. VascularInvasionDuringImplantationandPlacentation 23 ALLEN C. ENDERS AND THOMASN. BLANKENSHIP 4. OxygenRegulatesHumanCytotrophoblastProliferation, Differentiation,andInvasion:Implicationsfor EndovascularInvasioninNormalPregnancy andPreeclampsia 39 OLGA GENBACEV,YAN ZHOU, MICHAEL T. McMASTER, JOHNW. LUDLOW, CAROLINEH. DAMSKY, AND SUSAN1. FISHER 5. Embryo-MaternalInteractionsafterDiapause inaMarsupial 54 MARILYNB. RENFREE AND GEOFFREY SHAW IX x Contents 6. CellularInteractionsandtheCysteineProteinases intheProcessofMouseImplantation 67 BRUCE BABIARZ, SUZANNE AFONSO, ANDLINDA ROMAGNANO Part III. HormonalRegulation 7. NovelSteroid-RegulatedMarkersofImplantation 83 INDRANIC. BAGCHI 8. MolecularSignalinginImplantation 92 SANJOYK. DAS, BIBHASHC. PARIA, AND SUDHANSU K. DEY 9. IdentificationofProgesterone-RegulatedGenes intheUterus 107 CINDEER. FUNK, BERTW. O'MALLEY, AND FRANCESCO1. DEMAYO PartIV.MolecularMarkersofReceptivity 10. MucinsProvideaBarriertoEmbryoImplantation 123 MARYM. DESOUZA, GULNARA. SURVEYOR, XINHUI ZHOU, JoANNE JULIAN, ANDDANIELD. CARSON II. PotentialInvolvementofTrophinin,Bystin, andTastininEmbryoImplantation 132 MICHIKON. FUKUDA, DAITA NADANO,NAO SUZUKJ, AND JUN NAKAYAMA 12. OsteopontininHumanEndometrium: ARoleinEndometrialReceptivityand EmbryoImplantation? 141 CHRISTOS COUTIFARJS,AKINYINKA OMIGBODUN, PIOTR ZIOLKIEWICZ, AND JOHN HOYER PartV. TrophoblastFactors 13. TheRabbitasaModelforImplantation: InVivoandInVitroStudies 151 LORENH. HOFFMAN,D. RACHEL BREINAN, AND GARETHL. BLAEUER 14. RegulationofTrophoblastEndocrineFunction: ThePlacentaDoesItsOwnThingTranscriptionally...161 JEROMEF. STRAUSSIII ANDLEE-CHUANKAo Contents XI 15. TranscriptionFactorsRegulatingtheDifferentiation oftheTrophoblastCellLineage 167 IANC. SCOTTANDJAMESC.

The field of human artificial reproductive technology (ART) is continually advancing and has witnessed significant changes since the inception of Louise Brown in 1978. Though Louise Brown herself was conceived after the trans­ fer of a blastocyst, there remain significant confusion and debate regarding the stage at which the human embryo conceived in the laboratory should be replaced in the mother. Developments in culture media formulations, leading to the introduction of sequential media, have brought the role of the blasto­ cyst in human ART back into the spotlight. It was due to this resurgence of interest in the niche of extended culture in human infertility treatment that the symposium on "ART and the Human Blastocyst" was held. of this meeting within this volume bring to the forefront The proceedings the main issues raised with the transfer of embryos at the blastocyst stage. It is evident from the chapters that follow that ART needs to be perceived as a continuum of procedures, each one dependent on the preceding one, and all equally as important as each other. That is to say, the development of a com­ petent embryo is ultimately dependent on the quality of the gametes from which it was derived. With regard to the oocyte, this then places the emphasis on the physician to use a stimulation protocol that both produces quality oocytes and does not impair endometrial function. Maintenance of gamete and embryo quality is the laboratory's role.

The young investigator with an idea has to negotiate many institutional, federal, and industrial challenges in order to get a product to market.

Recent research suggests that adult growth hormone (GH) deficiency, whether of pathological or physiological origin, is associated with a dis­ tinct syndrome that includes alterations in body composition, endocrine­ metabolic function, immune competence, and physical and psychosocial well-being. Not surprisingly, substantial investigative effort is currently focused on validating the above hypothesis and on determining whether restoration of a normal GH-IGF-I axis in various states of adult GH deficiency is clinically useful, safe, and cost-beneficial. This book contains the proceedings from the Symposium on GHRH, GH, and IGF-I: Basic and Clinical Advances, held December 9 to 12, 1993, in San Diego, California, and sponsored by Serono Symposia USA, Inc. The conference was meant to highlight selected novel and exciting clinical research developments related to possible therapeutic uses of recombinant human GH and IGF-I, GHRH, GH releasing peptides, and related GH secretagogues. This meeting occurred only one year after a similar Serono symposium that was somewhat more oriented to novel basic science discoveries, thus attesting to the current scientific and clinical interest in this area.

Changes in the allocation of healthcare resources have raised issues related to the efficacy and outcomes of medical therapy and how such factors may be measured. The questions associated with the quality of life and functional capability of patients with chronic health conditions have been of special interest. Endocrine disorders have the potential for disrupting the general health and well-being of affected individuals and their families; thus they warrant serious attention. This symposium was convened in November 1997 at Palm Beach Gardens, Florida, to bring together medical, behavioral, and social scientists. The meeting fostered the presentation and discussion of the most current clinical research on the effects of various therapies on a wide range of endocrine disorders from diabetes to adrenal insufficiency and growth hormone deficiency. The participants, all noted national and international experts in their fields, focused their attention on both the biomedical value and effectiveness of treatment, as well as on the impact such treatments have on psychological states such as mood and cognition. Many presentations specifically emphasized the quality of life (QOL) indicators that now regu­ larly appear in many research protocols and reports. The pioneering work of two clinical researchers was a major highlight of the meeting and an Award of Recognition was presented to Robert Blizzard, M. D. , and John Money, Ph. D. , for their innovative and insightful work in pediatric endocrinology and psychosexual development.

They discussed the mechanism and regulation of motility, the metabolic strategy of human spermatozoa, the effects of exogenous fac­ tors such as antibodies, infections, and toxins, and finally the role of intracel­ lular calcium on sperm motility.

Sex-Steroid Interactions with Growth Hormone presents the proceedings of an international symposium held from October 22-25 in Naples, Florida. The proceedings provide new insights and concepts gained by molecular, cellular and neuroendocrine research into mechanistic interactions of the reproductive and somatotrophic axes. Chapters include discussions of the impact of sex steroids on growth hormone secretion in both children and adults; sex steroids, growth hormone releasing factor, and somatostatin; how sex steroids modulate growth hormone action on target issues; and differential effects of growth hormone secretagogues in men and women. This volume is designed for physicians, scientists and other health professionals interested or trained in clinical and basic endocrinology, growth or reproduction.

Embryoimplantationisaremarkableandcomplexprocess. Approachesde- velopedfromthefieldsofcellanddevelopmentalbiology,immunology, andmolecularbiologyhavegreatlyenhancedourabilitytostudythe sharedaswellasuniquefeaturesofembryo-uterineinteractions. Impres- siveandcriticalgroundworkhasbeenlaidbyalargeanddedicatedarray ofendocrinologists,reproductivebiologists,andanatomists. Thesestudies havesetthestagetoutilizesensitiveandsophisticatedtechniquestode- tectandmodulateproteinandgeneexpression. Justasthesymbiosisofmother andfetusiscriticalforthemaintenanceofpregnancy,soisthesynergyamong investigatorsfrommanydisciplines,bothinbasicandclinicalarenas,keyto unravelingthemysteriesofimplantationandplacentation. Alargegroupof contributorsinthisfieldhadtheopportunitytomeetanddiscussthestateof thisartwiththesupportofSeronoSymposiaUSA,Inc. Whileitisneverpos- sibletobringtogethereveryonewhohasplayedanimportantrole,itwas, nonetheless,bothexcitingandgratifyingtohavesomanycolleaguestogether forthisevent. Inthechaptersthatfollow,thehighlightsofthismeetingarepresented assummarizedbytheindividualpresentersofsevendifferentsessions.The topichasbeenconsideredfromthebroadsocialandethicalimplications ofmoderninvitrofertilizationandassistedreproductivetechnologiesto detailedmolecularcontrolsovereventsthatoccurduringembryonicdevel- opment,uterinepreparationforimplantation,andplacentalorganogenesis. Thesechaptersdemonstratethesignificantandrapidprogressbeingmade inthisfieldofbiologyandmedicine. Atthesametime,theyshowthat muchmoreneedstobedonetounderstandandfullyappreciatethispro- cess. Lessonslearnedfromthiseffortcanbeexpectedtocontinuetopro- videinsightsintoother,relatedfields. Ofthemanycontributorstoour understandingoftheprocessofimplantation,nonehavehadalargerim- pactthanourcolleague,AllenEnders. Dr. Endershasplayedaparamount roleindevelopingthebasicunderstandingofthecellbiologicalprocesses vii VIII Preface underlyingimplantationandplacentationinmanyspecies,includinghu- mans. Hecontinuestocontributeandguidethoughtintheseareas. The participantsofthissymposiumrecognizedDr. Enders'impressivecontribu- tionsbyholdingthiseventinhishonor. DANIELD. CARSON * Contents Preface vii Contributors xiii PartI. Development and Future ofHuman In Vitro Fertilization and Embryo Implantation I.ImplantationintheHumanasViewedbyCanonLaw, CivilLaw,andNaturalReason 3 HOWARDW. JONES, JR. , RICHARDA. MCCORMICK, AND SUSAN L. CROCKIN 2. TheImpactofMaternalAgeandOvarianAge onImplantationEfficiency...12 STEVEN SPANDORFER AND ZEV ROSENWAKS Part II. CellularAspects ofImplantation 3. VascularInvasionDuringImplantationandPlacentation 23 ALLEN C. ENDERS AND THOMASN. BLANKENSHIP 4. OxygenRegulatesHumanCytotrophoblastProliferation, Differentiation,andInvasion:Implicationsfor EndovascularInvasioninNormalPregnancy andPreeclampsia 39 OLGA GENBACEV,YAN ZHOU, MICHAEL T. McMASTER, JOHNW. LUDLOW, CAROLINEH. DAMSKY, AND SUSAN1. FISHER 5. Embryo-MaternalInteractionsafterDiapause inaMarsupial 54 MARILYNB. RENFREE AND GEOFFREY SHAW IX x Contents 6. CellularInteractionsandtheCysteineProteinases intheProcessofMouseImplantation 67 BRUCE BABIARZ, SUZANNE AFONSO, ANDLINDA ROMAGNANO Part III. HormonalRegulation 7. NovelSteroid-RegulatedMarkersofImplantation 83 INDRANIC. BAGCHI 8. MolecularSignalinginImplantation 92 SANJOYK. DAS, BIBHASHC. PARIA, AND SUDHANSU K. DEY 9. IdentificationofProgesterone-RegulatedGenes intheUterus 107 CINDEER. FUNK, BERTW. O'MALLEY, AND FRANCESCO1. DEMAYO PartIV.MolecularMarkersofReceptivity 10. MucinsProvideaBarriertoEmbryoImplantation 123 MARYM. DESOUZA, GULNARA. SURVEYOR, XINHUI ZHOU, JoANNE JULIAN, ANDDANIELD. CARSON II. PotentialInvolvementofTrophinin,Bystin, andTastininEmbryoImplantation 132 MICHIKON. FUKUDA, DAITA NADANO,NAO SUZUKJ, AND JUN NAKAYAMA 12. OsteopontininHumanEndometrium: ARoleinEndometrialReceptivityand EmbryoImplantation? 141 CHRISTOS COUTIFARJS,AKINYINKA OMIGBODUN, PIOTR ZIOLKIEWICZ, AND JOHN HOYER PartV. TrophoblastFactors 13. TheRabbitasaModelforImplantation: InVivoandInVitroStudies 151 LORENH. HOFFMAN,D. RACHEL BREINAN, AND GARETHL. BLAEUER 14. RegulationofTrophoblastEndocrineFunction: ThePlacentaDoesItsOwnThingTranscriptionally...161 JEROMEF. STRAUSSIII ANDLEE-CHUANKAo Contents XI 15. TranscriptionFactorsRegulatingtheDifferentiation oftheTrophoblastCellLineage 167 IANC. SCOTTANDJAMESC.

Inhibin, activin, and follistatin were originally discovered as hormonal fac- tors a decade ago. Subsequent studies revealed that they are widely distrib- uted anatomically and have multiple biological functions in a wide range of cells and tissues. Since the last Symposium three years ago, there has been remarkable progress toward defining activin's roles in controlling hormone secretion, cell differentiation and proliferation, mesoderm induction in em- bryos, nerve cell survival, and promotion of bone growth. Furthermore, the characterization of activin receptors as serine and threonine kinases and the identification of intracellular mediators such as the Smads have provided key elements for the eventual understanding of signaling mechanisms for activin and the other members of the TGF-beta superfamily. The unknown in this integrative field, however, remains far greater than the known. For ex- ample, we are just beginning to exploit the recently improved activin, inhibin, and follistatin two-site assays for the evaluation of the physiological and pathophysiological functions of these proteins.Also, we have only a rudi- mentary understanding of the mechanisms by which inhibin blocks activin, and many steps in the pathways linking the formation of ligand-receptor(s) complexes to transcriptional regulation are unclear. The aim of the Third Symposium was to bring together scientists from diverse fields to share technical and conceptual developments. The program was framed with the intention to include a wide range of timely research topics.

The biology of wound healing and tissue repair are increasingly being defined. At the same time, the availability of recombinant peptide growth factors for clinical investigation has prompted numerous trials of growth factor administration as adjunctive therapy to enhance the rate and quality of acute and chronic wound repair. New basic science information on growth factor function and regulation obtained in the research laboratory is actively being applied in animal studies and in clinical research settings. In addition to studies of surface wounds, an increasing number of investiga­ tions on growth factor administration have focused on healing and repair in nondermal tissues such as the intestinal tract and other organs. While the amount of new information on the molecular biology of growth factor expression, signaling, and function has been exponential in recent years, results of many clinical trials on growth factor administration in wound healing have been disappointing. This maybe due, in part, to the heterogeneity of clinical wounds and the patients who harbor them, less than adequate standardization of care in experimental and control groups, issues related to drug dosing, and inadequate control for important issues relevant to healing such as nutrient intake and underlying nutritional status.

The regulation of cell death in various reproductive tissues, as in other ma­ jor organ systems of the body, has become a focal point of research activity in many laboratories over the past few years. As such, the need for a "for­ mal" meeting to highlight recent work in this field, as well as to integrate knowledge from other sources (such as investigators working on cell death in cancer and immune function) in the broad context of identifying con­ served pathways that coordinate life-and-death decisions in diverse cell types, became apparent. Therefore, the goals of the Scientific Committee of the International Symposium on Cell Death in Reproductive Physiology, spon­ sored by Serono Symposia USA, were already predetermined by this need. Simply stated, we sought to bring together for the first time a select cohort of reproductive biologists and cell death researchers, many but not all cho­ sen based on their pioneering efforts in elucidating the fundamental aspects of apoptosis in reproductive and nonreproductive tissues, as a means to re­ view the current status of the field, foster new ideas, and promote scientific collaborations. In the ensuing chapters of this book, summaries of work dis­ cussed at the meeting are presented to emphasize both the diversity and the similarities in the occurrence and regulation of apoptosis in tissues of the male and female reproductive systems.

Quality of the Body Cell Mass presents proceedings of the International Symposium on Quality of the Body Cell Mass held in Fort Lauderdale , Florida. The text describes the states of the art of making measurements of body composition, including the methods and their interactions, and provides examples of applications that describe individual studies in the clinical areas of AIDS, obesity, osteoporosis, aging, wasting, and chronic disease. More than 50 illustrations complement the text.

This volume contains the proceedings of the XVth North American Testis Workshop, held in Louisville, Kentucky, April 7 to 10, 1999, to describe current advances in testis biology. The first two chapters provide a useful historical perspective of testis physiology and formulate compelling research questions about important aspects of sperm formation and function. This prologue sets the scene for the remainder of the volume that follows a logical progression, as the title implies, from stem cell to cell function, but that is necessarily preceded by sex determination, the quintessential requirement for there being a testis in the first place. The program for this XVth Testis Workshop evolved from recommenda­ tions of the scientific committee and their advice on the selection of invited speakers. The XVth Testis Workshop has a strong comparative flavor with contributions on worms (Caenorhabditis), flies (Drosophila), and chickens, which are models that permit and thereby reveal the power of genetic analy­ ses of the molecular mechanisms involved in spermatogenesis. A glimpse into the future is provided with information from EST, protein, and genome databases that already have an impact on progress in our understanding of the male germ cell. Although there is heavy emphasis in these chapters on cellular and molecular e,¥ents, database mining and translational profiling relevant to testis function and dysfunction and assisted reproduction tech­ nologies are not overlooked.

This book is composed of chapters prepared by invited speakers of the XIVth North American Testis Workshop, held in Baltimore, Maryland, February 19 to 22, 1997. The book reflects the desire of the Testis Workshop Scientific Commit- tee for a program addressing a broad array of current research focused on the germ cell, from its development through its death. Consequently, the research of those who have contributed chapters to this book addresses, or can be applied to, the hormonal and molecular regulation of spermatogonial cell development and nmc- tion (Nishimune, Orth, Russell, Dym), meiosis (Bickel, Wolgemuth, Handel, Trasler), spermatogenesis (Sassone-Corsi, Habener, Braun), cell death and aging (Campisi, Chen, Knudson, Swerdloff), and toxicant effects on spermatogenesis (Sharpe, Keice, Robaire, Meistrich). In their preface to the proceedings of the 1988 Testis Workshop, Drs. Larry Ewing and Bernard Robaire noted that the first published description of semi- niferous tubules in the testis was in 1668, by C.Aubry, and that "the exciting papers in these proceedings [of the 1988 Workshop] emphasize the significant progress that has been made since the mid-17th century in understanding testis and function. " It is quite clear that current research is proceeding at a breathtaking pace, with enormous strides having been made even since the XIIIth Workshop in 1995. If the XIVth Workshop succeeded, and this book succeeds, in convey- ing this excitement in our field (which, of course, was our intent), credit belongs to the creativity of the Scientific Committee, whose members were William J.

For the third time, specialists from all over the world met to present their most recent scientific results and to update their knowledge in the expand­ ing field of nutrition and, osteoporosis. Major nutrition-al factors, such as calcium and vitamin D, were reexamined, with special attention on the ef­ fects of calcium, given either as a supplement or in dairy products in chil­ dren and adolescents, and to vitamin D supplementation in the elderly. The RDA for calcium was questioned, and the calcium requirement was rede­ fined. Special attention was paid to proteins and their growth promoting action via IGF-l, as well as to the profound effects on calcium and bone metabolism of vegetarian diets or diets rich in acidic or alkaline foods. Although considered an environmental factor influencing the pathogenesis of osteoporosis, nutrition was discussed in relation to genetic conditions, because certain genetic conditions modifY patients' responses to nutritional deficiencies and to supplementary interventions. These proceedings report the wide spectrum of research currently being undertaken and the new perspectives this presents and emphasize the sig­ nificant and important impact of nutrition on bone health and disease.

The perimenopause is an extremely important time in a woman's life. In a similar but reverse sequence to puberty, it signals a change in ovarian status. Although some women pass through this transition without symptoms or concern, for many women, the perimenopause, which can last several years, is of great concern. Symptoms of estrogen deficiency, menstrual irregular­ ity, concerns over changes in mood, as well as reproductive concerns lead to anxiety and frustration. Because it is poorly understood, many clinicians are equally frustrated in finding ways to help their patients and question the appropriateness and/or need for treatment. This Serono Symposia USA, Inc., meeting was designed to help address some of these issues from both a basic science and a clinical perspective, and to provide a forum for discussion. The waning of ovarian function can be divided into two events that are dissociated: gametogenic and endocrine failure. Thus, the symposium was divided into three parts to address these two phenomena and to discuss treatment options. An outstanding international group of clinicians and investigators assembled to first address oocyte depletion and possible markers. Next the complex endocrine changes were discussed as well as the physiologic consequences of these changes. This included a discussion of hot flushes, bone and cardiovascular changes, menstrual irregularity, mood disturbances and depression, and anatomical changes in the ovary and breast. The third part of the symposium addressed treatment options, both in terms of symptoms as well as reproductive and fertility concerns.

Conceptual advances in the biological sciences are marked by the applica­ tion of new techniques and experimental strategies. Nowhere has this ge­ neric principle been more apparent than in the study of testicular cells, as judged by the evolution of themes presented at the Testis Workshop over the past 23 years. Like its predecessors, the 1995 Testis Workshop was structured to offer fresh insights and approaches for understanding the mechanisms of spermatogenesis and steroidogenesis. The chapters pre­ sented in this book emphasize three aspects of testicular cell function: first, the molecular analysis of the cell cycle; second, examination of the cell cycle, including the function and identification of specific macromolecules that direct the proliferation and differentiation of germ cells; and third, the development of Leydig cells and the role of specific macromolecules in the formation of testicular steroids. Each chapter is based on a lecture presented at the XIIIth Testis Work­ shop held on March 30 to April 1, 1995, at the Radisson Plaza Hotel in Raleigh, North Carolina. The selection of topics reflects the recommenda­ tions of the workshop'S organizing committee. Sincere thanks are due to the speakers who agreed to lecture and prepare chapters.

Immunomodulatory agents have been expressed in defined tissues or throughout the body, providing tools for studying the functional consequences of dysregulated expression of biologi­ cal response modifiers.

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.

The very first international working discussion on slow infections of the nervous system was entitled "Slow, Latent, and Temperate Virus Infec­ tions" and was held at the National Institutes of Health (NIH) in December 1964. The primary impetus was the discovery and investigation of kuru in New Guinea by D. Carleton Gajdusek, M. D. This working discussion brought together investigators in human and veterinary medicine, virolo­ gists, microbiologists, and neuropathologists actively engaged in laboratory work with viruses that illustrated properties of latency, masking, slowness, or temperateness, with emphasis on subacute and chronic neurologic dis­ eases of unknown etiology. In the Preface to the monograph of published papers presented at the working discussion, Gajdusek and Gibbs wrote the following: After microbiology had given solution to the etiology of most acute infections of the central nervous system and after fungi and bacteria had been incriminated in impor­ tant chronic disorders of the nervous system such as torula and tuberculosis men­ ingitis, we have been left, in neurology, with a wide range of subacute and chronic affections of the central nervous systems of unknown etiology. Some of these diseases, still listed as idiopathic, are among the most prevalent afflictions of the central nervous system. Many others with familial patterns of occurrence do not yet have their basic pathogenesis or underlying metabolic defect elucidated, although we tend to think of them as genetically mediated.

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.

This volume contains the proceedings of the Symposium on Molecular and Cellular Aspects of Periimplantation Processes, held July 15 - 18, 1994, in Boston, Massachusetts. Despite considerable research, the molecular and cellular bases of embryo-uterine interactions are still poorly understood. The papers included in this volume address recent advances in several areas in the field of implantation, including uterine receptivity, hormonal regulation, cell-cell interaction, growth factors/cytokines, immunobiology, and trophoblast invasion.

The XIIth North American Testis Workshop was held in Tampa, Florida, April 13 to 16, 1993. The program consisted of 23 invited lectures and 120 poster presentations. In keeping with the tradition of the Testis Workshop, every attempt was made to emphasize recent develop- ments in the study of endocrine and gametogenic functions of the male gonad. Although the main emphasis, reflected in the title of the pro- ceedings, was on the function and control of somatic cells in the testis, one session was devoted to germ cells and one to the studies of male reproductive development and function. The last session of the workshop was included in the program of the Postgraduate Course of the American Society of Andrology, which held its annual meeting in Tampa imme- diately following the workshop. This volume consists of 21 chapters prepared by the speakers and 8 chapters contributed by presenters of the posters. The Program Committee consisted of Drs. Nancy Alexander, C. Wayne Bardin, Andrzej Bartke (Chairman), Kevin J. Catt, Claude Desjardins, Maria Dufau, Michael Griswold, Norman Hecht, Aaron Hsueh, Dolores J. Patanelli, Bernard Robaire, and Richard Sherins.The workshop was generously funded by Serono Symposia, USA, which also agreed to handle registration, local arrangements, and publication of this volume. On behalf of the Program Committee and all participants, I would like to thank Dr. Bruce Burnett of Serono Symposia, USA and his staff for their efforts and support in every aspect of the organization of the workshop.

It is a genuine honor and a privilege of distinction to provide the foreword for the proceedings that follow. This marvelous symposium reflects the unique qualities of its two principal sponsors. Whenever the Oregon Regional Primate Research Center is involved in matters of science, we see a consistent record of exceptional quality in both the work is unequaled and the people who do it. Likewise, Serono Symposia, USA in assuring a world-class speakers' forum, utterly without taint of commercial influence. The proceedings published herein are a remarkable testimony, not only to the contributors, but to Drs. Brenner, Wolf, Stouffer, and Burnett, who have shepherded its conception, presentation, and publication. Readers will notice immediately one of the universal strengths of this total composition; that is, the diversity of investigational interests among attendees. Presentations on the core topic of primate in vitro fertilization and embryo transfer were joined by specialist presentations in related areas, including human-assisted reproductive technologies, reproductive physiology of the great apes, sperm biology, implantation mechanisms, cryobiology, coculture systems for embryogenesis, micromanipulation technologies, and genetic diagnosis of heritable diseases in the pre­ embryo. Even though pro-fertility issues understandably dominated this forum, there was significant attention given to fertility-control research, especially the role of primates in this endeavor (more on this subject below).

Trophoblast cells coordinate the activities of maternal and embryonic tissues by secreting hormones, cytokines, and various growth factors that selectively and specifically gain access to maternal and embryonic compartments. Abnormalities associated with trophoblast cell growth, differentiation, or function result in impaired embryonic development. Understanding the complexities of the trophoblast cell signaling system was the focus of the Serono Symposia, USA conference entitled Tropho­ blast Cells: Pathways for Maternal-Embryonic Communication, held August 6-9, 1992, in Las Vegas, Nevada. The conference was designed to provide a forum for morphologists, cell biologists, endocrinologists, and molecular biologists and for scientists investigating primate, ru­ minant, and rodent trophoblast biology. An important outcome of the conference was the communication achieved between basic scientists and clinicians. This volume represents the contributions of the invited symposium speakers. The opening keynote address of the conference was entitled "Chorio­ carcinoma and the Embryo" and was presented by G. Barry Pierce, M. D. , Centennial Distinguished Research Professor of the University of Colorado School of Medicine. The address is not represented in this volume, but deserves a special comment. Dr. Pierce's scientific con­ tributions have significantly influenced our understanding of trophoblast cells. Dr. Pierce, together with Dr. A. Rees Midgley, identified the origin of syncytial trophoblast cells of the primate placenta and discovered that these cells were responsible for the production of chorionic gonadotropin (J Exp Med 1962;115:289-94; Am J Pathol 1963;43:929-43; and Science 1963;141:349-50).

Since the awarding of the Nobel Prize to Drs. Guillemin and Schally iJ) 1971 for isolation and chemical characterization of gonadotropin releasing hormone, we have experienced a remarkable period of growth of interest in this hormone. The last 20 years have been characterized by a swift translation of basic science discovery into clinical utility. Approval of GnRH and its analogs for treatment of prostate cancer, endometriosis, of ovulation indicate the range and precocious puberty and for induction of these agents. of usefulness In order to bring together the leaders in the basic and clinical science of GnRH, a conference was organized on "Modes of Action of GnRH and GnRH Analogs" and held in Scottsdale, Arizona, February 26 to March 2, 1991. The presentations, given as chapters in this volume, show both the advances in the body of information in this discipline and the efforts underway to reduce basic science to clinical practice. The audience was a combination of representatives from universities, government, industry, and physicians in practice. The lively discussions and insightful questions indicated the interest in the topics discussed and frequently served to catalyze planned interactions of the meeting participants. The organizers are grateful to the speakers and poster presenters for their contributions and for the timely preparations of the manuscripts included in the present volume. We are also thankful to the staff of Serono Symposia, USA, for the organizational skills and support that allowed the meeting organizers to focus on the science and medicine presented.

The critical role of growth factors in normal as well as abnormal cellular growth and function has become overwhelmingly apparent in recent years. The significant advances in reproductive biology within this rapidly expanding field were highlighted at the Serono Symposia, USA, symposium entitled Growth Factors in Reproduc­ tion. The conference focused on growth factors as polyfunctional regulators of growth and development in the reproductive system. The program was organized into five areas: (1) growth factors as polyfunctional regulators of growth and development, (2) growth factors and gonadal function, (3) regulation of normal and neoplastic mammary growth, (4) regulatory peptides in reproductive tract development and function, and (5) embryo-maternal signaling. This volume constitutes the contributions ofthe invited symposium speakers and is organized into sections representing the five topic areas of the sessions. Drs. Eli Y. Adashi, Robert B. Dickson, David C. Lee, James Hammond, John A. McLachlan, and R. Michael Roberts, who served as chairmen ofthese sessions, not only provided invaluable advice and assistance in organizing the symposium, but contributed significantly to its content. The enthusiasm and esprit de corps of the poster presenters and discussion participants also helped make this symposium succeed as the first of its kind. Finally, special thanks are due Drs. James Posillico and Lisa Kern ofSerono Symposia, USA, for their guidance and support in the conception and planning of the symposium and in the publication of this volume.