Over the past 10 years there has been a veritable explosion of knowledge in working in this area are fortunate to meet their bile acid research. Those colleagues from time to time at International Meetings which are often held in attractive parts of the world. The 7th International Symposium on bile acids 'Bile Acids in Gastroenterology' was no exception. It took place in Cortina d'Ampezzo in the heart of the Italian Dolomites, from 17th-20th March 1982. This meeting was organised by a Scientific Committee, with representatives from Italy, the United States and Great Britain, in collaboration with the Italian Society of Gastroenterology. The format of the meeting was somewhat different from that of previous years. In addition to the free communications (verbal and poster presentations) which characte rise many scientific meetings, there was also an Advanced Postgraduate Course on bile acids given by a distinguished international panel of experts. Their contributions form the basis for this timely volume which should be of interest both to basic scientists and to clinical investigators alike. The editors are indebted to Dr Gian Germano Giuliani, Gipharmex SpA, Milano, whose generous support made the meeting possible. They also thank Mr P. M. Lister, Managing Editor, MTP Press Limited and Mrs Veronica Cesari, Italian Society of Gastroenterology for help with the publication of these proceedings. R. Herman Dowling ix 1 Liquid-solid extraction, lipophilic gel chromatography and capillary column gas chromatography in the analysis of bile acids from biological samples K. D. R.

During the 7th International Bile Acid meeting held in Cortina d'Ampezzo., Italy, during March 1982, there were two important Workshops dealing with recent advances in two areas of bile acid metabolism - Serum Bile Acids i, n Health and Disease and The Pathophysiology of the Enterohepatic Circulation. These Workshops complemented the broad range of topics in bile acid metabolism which were presented formally as part of a Postgraduate Course. The proceedings of these formal presentations have already been pub lished by MTP Press under the title Bile Acids in Gastroenterology but in view of the exciting, important, new information which emerged during both Workshops, the organisers of the meeting felt that it would be valuable to record and edit the proceedings of the Work shops, which form the basis of this volume. The advent of new techniques for measurement of total and indi vidual bile acids in serum now means that accurate and reliable 7 PREFACE measurements of bile acids in peripheral circulation are available to all. This has resulted in a veritable explosion of information in the serum bile acid field and, therefore, the appearance of a critical evalu ation of the technical and basic scientific and clinical aspects of measuring serum bile acids is indeed timely."

In 1983 and 1984, I had the pleasure of being invited to Europe for the Cour- se of Hepatobiliary Surgery started by Professor Hepp and continued by Pro- fessor Bismuth. In these courses, I demonstrated many slides and movies of intraoperative echography that Makuuchi, one of my staff members, had made using the transducer that he was the first to develop. The topic of Intraoperative Echography had an enormous impact on the audience, and its use has since spread rapidly over the European countries, by virtue of the first Italian edition of Professor Gozzetti's book on Intra- operative Echography and Professor Bismuth's monograph on the same top- ic. I had been, therefore, unwittingly a very fortunate transmitter of intra- operative echography to Europe by means of Makuuchi's slide file. I am extremely honoured that the Italian Edition written by Gozzetti, Maz- ziotti and Bolondi has been dedicated to me. Also in this English Edition, Professor Gozzetti very kindly asked me to write a few words. It is an extra- ordinary pleasure for me to emphasize how this book is easy to read and understand, maybe by virtue of the profound Italian tradition of artistic expression since the Renaissance. On the other hand, a variety of series of intraoperative echographic images as well as resected specimens are arranged in an excellent manner.