Ferment, a sign of progress in any scientific field, has previously been lacking in the area of cryptorchidism, where the only activity has been in improving operative methods. Now, however, profound changes in the care of boys with cryptorchidism are being brought about; ideas are arising from a fresh look at comparative anatomy, and histological and experimental observa tions are being supplemented by clinical tests made possible by new hormonal agents. The treatment of cryptorchidism begins with its recognition by the pediatri cian, who until now has shown little interest because of disappointing results from chorionic gonadotropin administration. As for the surgeon, his bent toward restoration of normal anatomical relationships has kept his attention focused on the development of better surgical technics to bring the recalci trant testis into the scrotum. Both specialists have avoided the primordial question of why the testis did not descend properly. If this were known they would treat the cause of cryptorchidism, and not be satisfied merely with trying to correct its end result. As one reads this book, one sees that in most patients cryptorchidism is not caused by some anatomical structure blocking the way or by some deformity of the testis interfering with the transport mechanism. Rather, deficiencies in the hormonal environment of the fetus retard the developmen tal sequences essential to the normal differentiation and descent of the testis. The clinical solution is thus to provide the deficient substances."

This book is the proceedings of the Falk Symposium No. 127 on Autoimmune Diseases in Paediatric Gastroenterology' (IV International Falk Symposium on Paediatric Gastroenterology), held in Basel, Switzerland, on November 8-9, 2001. The symposium focused on the role of the immune system, both the acquired and the innate systems, in inflammatory bowel disease (IBD) in children and adolescents. The innate system has an important fundamental role in host defence by initiating immune responses against potentially deleterious matter. However, a mutation within the innate system may elicit an immune response against the host: hence, an autoimmune response.

Chronic autoimmune hepatitis occurs predominantly in young people, and especially in women. Immunological changes are conspicuous. Tissue antibodies are found in a large number of patients. This is a disease of disordered immunoregulation marked by a deficit in suppressor T cells causing the production of autoantibodies against specific hepatocyte surface antigen. Liver membrane protein is found in the sera of patients with autoimmune chronic acute hepatitis and with primary biliary cirrhosis (PBC). The latter condition of progressive granulomatous destruction of intrahepatic bile ducts is, in many respects, analogous to the graft-versus-host syndrome where the immune system has become sensitized to foreign HLA-molecules.

Primary sclerosing cholangitis (PSC) is another condition of unknown origin. All parts of the biliary tree can be involved in a chronic, fibrosing, inflammatory process that results in obliteration of the biliary tree and ultimately in biliary cirrhosis. About half of the patients also suffer from ulcerative colitis and rarely from Crohn's disease. Circulating antibodies to some antigens are found in obstructed portal tracts, as well as increased concentrations of biliary immune complexes in patients with PBC.
In all three previous Falk symposia on paediatric gastroenterology, attention was focused on the role of the innate immune system in the aetiology of IBD. It has become increasingly clear in recent years that the innate system has a much more important and fundamental role in host defence. The decision to initiate an immune response is one of the major roles of the innate system. Mutations within this system could transform it into becoming constitutively active, resulting in an inflammatory reaction and thus eliciting an autoimmune response.

Following an introduction to the basic phenomena of autoimmunity, the proceedings discuss clinical aspects of autoimmune diseases. In particular, current knowledge and the state of the art about the diagnosis and treatment of the autoimmune diseases of the gastrointestinal tract are described by world-renowned experts. The book also contains the short presentations on selected topics, as well as abstracts of the mini-posters read by title, which were included in the symposium.

Despite significant progress in modern gastroenterology, the aetiology of inflammatory bowel disease as well as coeliac disease is still to a great extent unknown and poorly understood. The principles of treatment - particularly of IBD - emphasize the importance of a combined medical and surgical approach. This book is the proceedings of an international symposium that brought together workers from many disciplines involved in the treatment of IBD and coeliac disease, and is a useful update on recent advances in paediatric and paediatric-surgical gastroenterology. F. Hadziselimovic, B. Herzog, A. Biirgin-Wolff vii List of Principal Contributors M. BUROELSKI F. HAOZISELIMOVIC Kinderklinik Department of Gastroenterology Medizinische Hochschule Hannover Basler Kinderspital Postfach 61 01 80 Rbmergasse 8 CH-4005 Basel 0-3000 Hannover 61 Switzerland FRG H. K. HARMS A. BURGIN-WOLFF Dr. V. Hauner'sches Kinderspital Basler Kinderspital Lindwurmstrasse 4 Rbmergasse 8 0-8000 Munich 2 CH-4005 Basel FRG Switzerland A. H. CO LOONY W. T. J. HEKKENS Department of Physiology Harvard Medical School Faculty of Medicine Division of Urology The Children's Hospital University of Leiden 300 Longwood Avenue Wassenaarseweg 62 Boston, MA 02115 PO Box 9604 NL-2300 RC Leiden USA The Netherlands C. P. FLIEGEL Department of Radiology B. HERZOG Basler Kinderspital Pediatric Surgery Rbmergasse 8 Basler Kinderspital CH-4005 Basel Rbmergasse 8 Switzerland CH-4005 Basel Switzerland J. -O. GEBBERS Institute of Pathology B. S. KIRSCHNER Kantonsspital Wyler Children's Hospital CH-6000 Luzern 16 5825 S. Maryland Avenue Switzerland Chicago, IL 60637 USA A. M. GRIFFITHS Division of Gastroenterology M. L.

Cytological techniques have greatly improved in the last twenty years, largely as a result of further development of the microscope. Electron microscopy, in particular, has opened up great prospects for the study of cell morphology, while the develop ment of radio-immuno-assay has brought great progress in endocrinology. The applica tion of these two techniques, which are complementary to each other and provide mutually supporting evidence, is the subject of this monograph. The work is divided into two parts. The first deals with the ultrastructure of normal testicular development, describing four main elements of the testicle - the germ cells, the Sertoli cells, the peri tubular connective tissue and the Leydig cell- with details of their individual development. To make the electron micrographs more easily understandable, diagrams have been used to explain the most important points. The second part deals with cryptorchid testicles, including the primary and sec ondary changes involved and morphometric studies of the secondary changes. The significance of these ultrastructural observations for the treatment of cryptorchidism is emphasized. With the aid of radio-immuno-assay the level of testosterone in cryp torchid mice was determined and comparisons drawn between the ultrastructural changes in cryptorchidism in mouse and man. The experimental studies served as a basis for the hypothesis that, in all probability, a congenital disturbance of the hy pothalamo-hypophyso-gonadal axis is responsible for cryptorchidism. I hope that this monograph will contribute towards a better understanding of normal and cryptorchid testicular development and of the etiology of cryptorchidism."

Despite significant progress in modern gastroenterology, the aetiology of inflammatory bowel disease as well as coeliac disease is still to a great extent unknown and poorly understood. The principles of treatment - particularly of IBD - emphasize the importance of a combined medical and surgical approach. This book is the proceedings of an international symposium that brought together workers from many disciplines involved in the treatment of IBD and coeliac disease, and is a useful update on recent advances in paediatric and paediatric-surgical gastroenterology. F. Hadziselimovic, B. Herzog, A. Biirgin-Wolff vii List of Principal Contributors M. BUROELSKI F. HAOZISELIMOVIC Kinderklinik Department of Gastroenterology Medizinische Hochschule Hannover Basler Kinderspital Postfach 61 01 80 Rbmergasse 8 CH-4005 Basel 0-3000 Hannover 61 Switzerland FRG H. K. HARMS A. BURGIN-WOLFF Dr. V. Hauner'sches Kinderspital Basler Kinderspital Lindwurmstrasse 4 Rbmergasse 8 0-8000 Munich 2 CH-4005 Basel FRG Switzerland A. H. CO LOONY W. T. J. HEKKENS Department of Physiology Harvard Medical School Faculty of Medicine Division of Urology The Children's Hospital University of Leiden 300 Longwood Avenue Wassenaarseweg 62 Boston, MA 02115 PO Box 9604 NL-2300 RC Leiden USA The Netherlands C. P. FLIEGEL Department of Radiology B. HERZOG Basler Kinderspital Pediatric Surgery Rbmergasse 8 Basler Kinderspital CH-4005 Basel Rbmergasse 8 Switzerland CH-4005 Basel Switzerland J. -O. GEBBERS Institute of Pathology B. S. KIRSCHNER Kantonsspital Wyler Children's Hospital CH-6000 Luzern 16 5825 S. Maryland Avenue Switzerland Chicago, IL 60637 USA A. M. GRIFFITHS Division of Gastroenterology M. L.