Extracellular matrix (ECM) turnover is a widespread but in completely understood process. Many studies have been con ducted with the aim of discovering the general mechanisms which produce and maintain the ECM in tissues. Wound re pair in animals has always been a suitable "tool" for exploring these mechanisms. In such a pathologic event, the different components of the healing system can be readily observed since they are exaggerated. It has now become clear that the regulation of protease/inhibitor activity is one of the most im portant steps in maintaining the integrity of ECM in the normal as well as in the pathologic state. As far as the repair process is concerned, a failure in such regulation may result in abnormal wound healing ranging from nonhealing wounds to hyper trophic scarring. Experimental findings have been directly applied in clinical practice. For example, the importance of debridement in nor mal and especially in poorly healing wounds has become much clearer in the recent past. Different methods have been proposed to obtain an optimal wound bed in order to perform skin transplantation. Both mechanical and physical debridement procedures un doubtedly offer some advantages and are essential when extensive third degree burns have to be treated. On the other hand, pain, excessive blood loss, and overall broad and indi scriminate debridement are common negative side effects. Thus, many enzymic formulations have been proposed and used in practice by clinicians all over the world."

This book is the fruit of lectures given during the symposium "Proteolytic Enzymes and Wound Healing" at the Joint Meet ing of the Wound Healing Society and the European Tissue Repair Society held in Amsterdam, August 22-25, 1993. Look ing back, we can conclude with satisfaction that the meeting was a great success, with regard to both the number of partici pants and the scientific level. Enormous progress is being made in the field of wound heal ing and tissue repair. It was therefore of prime importance that one fundamental aspect in the healing of chronic wound- the proteolytic debridement of tissue necrosis - be given thorough attention during the above-mentioned symposium. Renowned authors dealt with the various aspects of proteoly tic enzymes and wound healing, so that a unique overview was given. The lectures were written up and arranged into the various chapters of this book, which should provide the reader with a practical guide in understanding and treating necrotic wounds. Wiete Westerhof, M. D., Ph. D. President of the Organizing Committee of the Joint Meeting of the Wound Healing Society and the European Tissue Repair Society Contents Pathobiology of Necrosis P. K. Das and W. Westerhof.. ................................... ."