Basic research has thrown new light on the importance of free radicals in biol- ogy and medicine. The clarification of interactions opens numerous physio- logical and pathological processes to closer scrutiny. The pathophysiological processes are now understood, even though the basic mechanisms of free radi- cal reaction have as yet escaped full explanation. Asystematic approach makes it possible to re-evaluate and contrast the in- dications, reactions, and prospects for success. The extracellular significance of oxygen radicals in inflammatory condi- tions and their role in the destruction of bacteria in the phagosome of granu- locytes were primary factors intensifying research. Nature also provides a great number of examples which demonstrate that through the emergence of free radicals highly toxic combinations can form from innocuous substances. The reverse principle may also be encountered. Taking into account free radical reactions in pathomorphological investi- gations helps prepare the ground for causal therapy. Research into these phen- omena will contribute to a better understanding of physiological and patho- physiological processes. Many questions still remain unanswered, and it will take several years of research before the final stone is unturned.

Based on the results of the latest congress of the European Association for the Study of the Liver (EASL), this volume makes excellent reading since it explores in detail the role of free radical reactions in liver diseases. Studies in recent years using various methods have shown that free radicals play an important role in toxic liver disorders. For this reason, the current scientific knowledge is presented in this balanced, clinical portrayal. The account refers to the many observations, experiencesand evaluations that have been made both clinically and experimentally. Two major areas discussed concern the pathophysiological changes by free radicals and the therapeutic possibilities that have come to light.

Basic and clinical research have in recent years contributed towards clarifying certain aspects ofthe epidemiology, pathogenesis, prevention, and treatment of liver diseases. New diagnostic techniques have, moreover, facilitated observations on the evolution of such diseases. Nevertheless, a numberofquestions still remain, especially in the assess- ment and management ofliver patients. The hope that such questions can be answered justifies publications like the present one, which provide experts an opportunity to pre- sent the results oftheir research. The papers collected in this volume cover all aspects of the assessment and man- agement of hepatobiliary disease. The focal points are three summaries ofthe state of the art. The first deals with the highly topical problem of liver transplants from the point ofview ofpatient selection. Roger Williams in fact stresses the urgent need to ex- ercise caution in the selection ofsuitable candidates. This is especially true at the pre- sent time when cyclosporin A, a new immunosuppressive drug now available on the market, has significantly changed the natural history ofsurvival after liver transplanta- tion.