I. Klatzo – författare

The last decades of the past century have brought relentless progress in molecular genetics, opening dramatic opportunities for modifying human life by gene therapy or by cloning new human beings. In this frenzy of new discoveries the names of Cecile and Oskar Vogt, who one hundred years ago envisaged these developments and laid the foundation for modern, genetically oriented neuroscience, have been practically forgotten.This makes most timely the treatise by Igor Klatzo, who spent several years with the Vogts at their Brain Research Institute in the Black Forest, Germany, and then continued his brain research as the Chief of the Laboratory of Neuropathology and Neuroanatomical Sciences at the NIH in Bethesda, MD.Klatzo brings, in addition to the recognition of the Vogts' greatness in pioneering modern brain research, a lively picture of their personalities, which includes their struggles against the rigid rules of society, and political suppression, the latter associated with the risk of their lives.

The topic "Cerebrovascular Transport Mechanisms" was chosen by the General Couneil of the International Society of Neuropathology as one of the four main symposia at the IX International Congress of Neuropathology, September 1982 in Vienna. The chairmen of the symposium were asked to structure a program which would cover the reeent devel- opments in this field and which could serve as a background for free communications, relevant to this topic, submitted by the participants of the Congress. Cerebrovascular transport mechanisms refleet the main function of the blood-brain barrier in providing optimaI, homeostatically regulated, biochemical environment for the brain. It is obvious that disturbanees of this function may play a significant role in patho- physiology of various brain disorders.Since the elucidation of the complex blood-brain barrier phenomenon, consisting of various "barrier systems", necessarily requires applica- tion of multidisciplinary approaches, the program of this symposium was structured by evaluation of ultrastructural, cytochemical, physiological, biochemical, pathophysiological and therapeutic aspects of the blood-brain barrier by invited, recognized experts in respec- tive areas. As aresult, this volume of the proceedings of the symposium attempts to summarize much of today's knowledge on cerebrovascular transport mechanisms in health and disease, and is supplemented by the abstracts of free communications dealing with the most reeent research in this field. We hope that this volume wil1 serve both as an introduction and a reference book, and that it wil1 stimulate further research.

The maturation phenomenon, first described by Ito et al. in 1975, refers to postischemic changes that develop hours or days after an ischemic insult. The delayed neuronal death of CA1 pyramidal cells of the hippocampus is a classic example. The report of the phenomenon boosted research in the field, as it became evident that ischemic damage is not a sudden event, but a process potentially susceptible to therapeutic intervention. Since then a growing number of studies have improved our knowledge on mechanisms of cell death and recovery. This volume contains the presentations of the Fifth International Workshop on Maturation Phenomenon in Cerebral Ischemia, held in Banff, Alberta, Canada, in April/May 2002. It outlines the present status of investigations and provides further stimulation for research in this field.

The maturation phenomenon, first described by Ito et al. in 1975, refers to postischemic changes that develop hours or days after an ischemic insult. The delayed neuronal death of CA1 pyramidal cells of the hippocampus is a classic example. The report of the phenomenon boosted research in the field, as it became evident that ischemic damage is not a sudden event, but a process potentially susceptible to therapeutic intervention. Since then a growing number of studies have improved our knowledge on mechanisms of cell death and recovery. This volume contains the presentations of the 4th international symposium, held in New Orleans in October/November 1999, grouped in sections covering apoptosis and/or necrosis, neuronal recovery vs. death, and protection against infarction. It outlines the present status of investigations and provides further stimulation for research in this field.

Many nerve cells of the brain are not killed outright but rather suffer a "delayed neuronal death" or even recover. This well-known fact has led to the concept of "maturation phenomenon", which implies that the maturation of ischemc lesions may provide a window of opportunity, that is, a period of time during which the injury to neuronal elements is still reversible if the proper therapeutic measures are applied. The symposium on Maturation Phenomenon in Cerebral Ischemia was the first international meeting to focus primarily on this subject; the resulting publication contains presentations and discussions by prominent researchers engaged in this field. This book should stimulate further research on the potential of brain tissue for recovery, particularly with regard to a functional recovery of neurons suffering from chronic ischemic injury.

The patriarch of experimental pancreas research is REIGNIER DE GRAAF (1641-1673). He carried out the first experiments with dogs in order to ob­ tain fistular secretion (1664). But only few years later, the just arisen interest in the physiology of the pancreas was severely set back by remarks of CONRAD BRUNNER. In 1682, BRUNNER expressed his belief that on the basis of experi­ ments he had carried out the pancreas was a vitally unimportant organ. He overlooked that after ligation of the main duct (discovered in the turkey by HOFMAN in 1641 and in a human cadaver by WIRSUNG in 1642), in the dog an accessory duct (described by SANTORINI in 1724) usually maintains an adequate flow of secretion. EBERLE in his monograph (1834) confirmed the emulsifying capacity of the pancreatic juice which had already been suggested by SYLVIUS (FRAN­ CISCUS DE LE BOE, 1614-1672) and he dealt with the essential enzymatic functions of the pancreatic juice such as amylolysis, lipolysis and proteolysis. Since HEIDENHAIN (1875), we know that for example trypsin (largely isolated by KUHNE in 1867) is situated in the acinar epithelial cells as zymogen in inactive form; it is thought that the action of "acid" on the glandular tissue is needed for inducing the "enzymatic activity". According to what we know now about the central role of acidosis in the activation of zymogen this topic is, of course, of topical interest.