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The limitations of current techniques using measures of volume and pressure alone to describe biomechanical function and sensory responses are presented with constructive and interesting discussion describing more appropriate methodology. In-depth discussion is given about conformational changes that occur within the tissue in response to applied forces that are not accounted for by currently used measuring techniques. Emphasis is made that stress and strain generated within tissue need to be detected using appropriate techniques as they reflect the biomechanical changes occurring in response, primarily, to distention of the gut. The importance of tissue deformation during the application of forces is described with evidence for tissue remodelling in response to prolonged or repeated deformation or stressors which need to be considered when investigating gastrointestinal function. Mathematical modeling of theoretical tissue responses is presented with derivation equations for determining unknown functions. This modeling is an aid to the understanding of biomechanical systems that may seem rather daunting on first glance but is easily followed and relevant to the topic of discussion. This mathematical modeling provides the substance behind the argument for more sophisticated investigative techniques. These would enable more appropriate interpretation of the biomechanical responses to the stimuli presented, and a better understanding of the mechanisms underlying the variations in both motor and sensory responses within the gut. The aim of the book is to introduce Biomechanics as a methodology that should be applied to gastrointestinal function. The material is well-presented and easily read even by the relative novice. There are references throughout the book to many relevant publications and further reading material for those who wish to extend their knowledge base about this interesting area. This book is aimed at those investigators with enquiring minds who would like to extend their basic knowledge about tissue biomechanics and motility and so derive more clinically useful information about normal physiology and an understanding of the tissue pathophysiology resulting in dysmotility within the gastrointestinal tract. I recommend this book to all serious researchers in gastrointestinal motility as it provides a clear message that for appropriate investigation of the motor and sensory function of the gastrointestinal tract, appropriate techniques should be used that allow all the biomechanical factors inherent within the biological system to be taken into consideration during the investigative process. Bottom Line: Recommended for researchers in gastrointestinal motility.
JOSEPHINE D. BARLOW, PH.D., BSC(HON) FAGIP Department of Gastrointestinal Physiology G.I. Sciences Hope Hospital Salford, England
GASTROENTEROLOGY Vol. 126, No. 2
Practical Gastrointestinal Endoscopy, 5th Edition. By Peter B. Cotton and Christopher B. Williams. 224 pp. $169.95. Blackwell Publishing, Malden, Massachusetts, 2003. ISBN 1405102357. Web address for ordering: www.blackwellpublishing.com This fifth edition of what has become the classic textbook covering the basics of gastrointestinal endoscopy should be required reading for all gastroenterology trainees and their instructors. The text has been completely revised and updated since the previous edition, now 7 years old, to include technical advances, as well as changes that have occurred in gastroenterology practice. The major change in the book is the omission of chapters on advanced endoscopy such as endoscopic retrograde cholangiopancreatography (ERCP), which appropriately do not belong in a book that aims to cover the basics of endoscopy that a first-year trainee should learn. The book is an invaluable asset to augment the largely hands-on training of gastrointestinal endoscopy. The authors emphasize both the technical aspects of doing an endoscopic procedure, as well as the overall integration of endoscopy into patient management. The importance of teamwork is stressed, as well as appropriate behavior in the endoscopy suite, something that all trainees should abide by. The basics of patient education and preparation, informed consent, and ways to reduce the risk of complications are emphasized. The description of how to reliably get to the cecum during colonoscopy is a masterful description of the minute technical details that are keys to success. The text is easy to read and liberally peppered with spicy pearls of wisdom from the authors who are both talented endoscopists and educators. For example, white wine or diluted spirits are suggested as a way to boost morale during patient preparation for a colonoscopy! The book is accompanied by 2 read-only compact discs (CDs) that complement the text descriptions. Organized to follow the written material in the book, the CDs are amply illustrated with video sequences of the endoscopist handling the endoscope, as well as the endoscopic images. Clear indexes and navigation tools allow one to move easily to areas of interest. The colonoscopy CD is especially well done, with numerous short endoscopic videos to illustrate findings and techniques. Illustrations using the 3-dimensional image guide system developed by one of the authors make it easy to understand how loops form in the colonoscope, and how these loops can be reduced. There are some minor differences from endoscopy guidelines published by the American Society for Gastrointestinal Endoscopy (ASGE), likely reflecting the varying practices of endoscopy internationally. For example, a 60-minute glutaraldehyde soak is recommended for endoscopes used in patients with AIDS or tuberculosis rather than the universal application of the standard soaking times advocated by the ASGE. Mannitol is also listed as an acceptable laxative prior to colonoscopy despite the availability of alternatives and the risk of explosion with electrocautery. The presence of a cardiac pacemaker is said
to contraindicate use of argon plasma coagulation, a concept that is not widely accepted in the United States. There are no books comparable to this one for teaching the fundamentals of gastrointestinal endoscopy. Training guidelines from the ASGE cover some of the areas presented, but not in as much detail or with the graphical illustrations provided on the CD. Videotapes available from the ASGE cover some of the therapeutic endoscopic procedures in more depth than this text, but do not cover the basics of endoscopy, as well as this text and its accompanying CDs. All beginning trainees in gastrointestinal endoscopy should be required to read Practical Gastrointestinal Endoscopy and study the accompanying CDs. They should do so at the beginning of their gastrointestinal fellowship and then return to the material frequently during training. Instructors of endoscopy should find the material helpful in their own teaching practices. I also encourage senior endoscopists to read this text as a good review of the basics and to pick up some pearls that will enhance their own endoscopic skills. I only hope the authors follow up this text with a similar book for teaching advanced endoscopy such as ERCP and endoscopic ultrasonography. Bottom Line: Required reading for all gastroenterology trainees and their instructors.
MICHAEL B. KIMMEY, M.D. University of Washington Seattle, Washington Bile Acids and Pregnancy–Falk Workshop. Edited by U. Leuschner, P.A. Berg, and J. Holtmeier. 80 pp. $56.00. Kluwer Academic Publishers, Boston, Massachusetts, 2002. ISBN 0-7923-8782-1. Web address for ordering: www.wkap.nl This little book contains summaries, some very brief, of a Falk Workshop held in June 2002 in Freiburg. The title is misleading, as the first portion of the book deals with the as of yet still unanswered question: why does the pregnant woman not reject her fetus? Of these 5 papers, 3 are abstracts only. The remaining 2 are fascinating. Dr. Vacchio, from the NIH, discusses the transient state of tolerance induced in the pregnant woman, a state that allows the foreign fetus to stay aboard until maturity. Pregnancy is “non-inflammatory”—not associated with trauma, which elicits a “danger” signal, and awakens the immune system. Instead, the steroids and cytokines of the placenta bias the mother’s immune system to Th-2 type responses, thus allowing the pregnancy to proceed. Later in the book Dr. Formby from the Rasmus Institute in Santa Barbara notes that 30% of human pregnancies are lost early in gestation and that the cause of the 60% or more of pregnancies that result in spontaneous abortion remains unknown, but may be due to immune mechanisms (“rejection” of the fetus). These investigators propose that one of the steroid modulators of the maternal immune response is progesterone. The latter two thirds of the book deals with more familiar territory– bile acids and pregnancy–with emphasis on the disorder known as intrahepatic cholestasis of pregnancy (ICP).
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Three of these papers are from Professor Reyes’s unit in Santiago, Chile, where ICP is quite common. He reviews the clinical hallmarks of the condition, and the data on alterations in progesterone and bile acid metabolism in affected pregnancies. Ursodeoxycholic acid (Urso–marketed by Falk as Ursofalk) ameliorates the pruritus of ICP, and reverses the abnormalities in progesterone and bile acid metabolism. One of the most vexing problems about ICP is its association with an increase in prematurity and stillbirth. Dr. Palma reports data demonstrating a decrease in prematurity and an attendant increase in birth weight in patients with ICP treated with Urso. Is normal pregnancy a relatively cholestatic state? We know that there is a “physiologic cholestasis” of the newborn–reflecting immaturity of the mechanisms of the enterohepatic circulation of bile acids. Dr. Arrese et al. would have us believe so, and argue that women with ICP have either an inherited exaggeration if this normal physiology, or a polymorphism in the response to certain xenobiotics. Dr. Mazzella and the group from Bologna are quite persuasive that the appropriate dose of Urso for ICP is 20 –25 mg⫺1 䡠 kg⫺1 䡠 day, higher than the dose usually used in treating PBC. The final chapter, from Calmus and the group at Hopital Cochin in Paris, explores the immune modulatory effects of bile acids, and the beneficial effects of Urso. It’s too bad that the editor was unsuccessful in getting a real manuscript from several of his participants–the abstracts are tantalizing, and not all of us could go to the meeting. The chapter by Dr. Marin looks interesting, but was written in Faulknerian sentences that were virtually impenetrable. What did I learn? First of all, the data supporting the use of Urso in ICP is becoming more and more compelling, even for those of us living in the United States where the use of any medication in pregnancy is scrutinized. Its use is backed up by clinical and experimental studies showing improvement in laboratory results and outcome. Secondly, the field of the relative “immune privilege” of pregnancy is a fascinating one, particularly for those of us who struggle to understand the immune responses to hepatitis C, and to control the immune reactions to liver transplantation.
CAROLINE A. RIELY, M.D. Departmemts of Medicine and Pediatrics University of Tennessee Health Science Center Memphis, Tennessee Molecular Biology and Immunology in Hepatology. Edited by T. Tusji, T. Higashi, M. Zeniya, and K.-H. Meyer zum Bu¨ schenfelde. 362 pp. $145.00. Elsevier, 2002. ISBN 0-444-50653-5. Web address for ordering: www.elsevier.com Many key diseases of the liver involve viruses, the immune system, or both. Substantial progress in molecular virology and molecular immunology makes possible a synthesis of these diverse areas, and this has been attempted in a book, “Molecular Biology and Immunology in Hepatology: Advances in the