NATO ASI Subseries A: – serie

This volume summarises the lecture and poster sessions of a NATO advanced workshop held in Edinburgh, July 15th-19th, 1985. The workshop was held to bring together plant scientists of many different disciplines but who share a common interest in the regulatory role of calcium in plant development. Although this volume covers the formal proceedings, an equal length of time was devoted to discussion both in large and small groups. A little of the flavour of the directions and character of the discussions will be found in the final article by David Clarkson which was written to cover this other­ wise uncovered area of the workshop. The volume reflects much of the current excitement in the field of plant calcium research. Many of the participants are pioneers in their res­ pective areas and the extent to which the last five years has seen a drama­ tic unfolding, a complete inversion of the role of calcium from simple macro­ nutrient to major metabolic and developmental controller is recounted here. The material is new and much of it unpublished. In plant physiology, the eighties may yet be designated the decade of calcium.

In the summer of 1976 a successful workshop on nucleic acids and protein synthesis in plant systems was organised in Strasbourg by Jacques Weil and Lawrence Bogorad. The participants in the workshop, were, without exception, excited both by the quality of the work discussed and by the rapid progress being made in several areas of genomic analysis and expression in plants. It also became apparent that there was a need for an international assembly of this sort at regular intervals. These workshops not only encourage stim­ ulating discussion and constructive thinking but also result in increased collaboration and productive liaison between laboratories with common interests. Hence a ten-day advanced studies institute course was organised in Edinburgh from 11-21 July 1979, and in this volume we have published the contributions given by the invited speakers. The subjects discussed covered most areas of plant molecular biology and the lecturers were asked to balance a review of their chosen subject with the results of their own recent research and likely future advances. Probably the most important technical advance since the previous meeting of this group in Strasbourg, was the application of restriction enzyme analysis and cloning techniques. This is illustrated in many of the published lectures and was the basis for many of the more informal discussion sessions.

The identification and quantitation of environmental risk in humans is one of the main problems to be solved in order to improve the protection of individuals and of human populations against phys­ ical and chemical pollutants. Epidemiology plays a central role in the evaluation of health risk directly in human populations. In this volume are collected 33 lectures presented at the AS! course on "Epidemiology and quanti tat ion of environmental risk in humans from radiation and other agents: potential and limitations", sponsored by NATO and Italian Association of Radiobiology and or­ ganized by ENEA. The course has been devoted to a number of aspects of environ­ mental risk analysis and evaluation based on epidemiological in­ vestigation. Basic epidemiological concepts and methods have been reviewed. Fundamentals of dosimetry and microdosimetry were presented in re­ lation to the contribution of epidemiology in defining the dose­ effect relationships for radiation carcinogenesis and its relation with age, sex and ethnicity. The mechanisms of carcinogenesis as a multi-stage process were illustrated. One of the main topics was 'cancer epidemiology' and its cor­ relation with: - occupational and non-occupational exposure to ra­ diation - diagnostic and therapeutic irradiation - cancer proneness - hereditary and familiar diseases - abnormal response to carcino­ gens - environmental pollution in air and water - exposure to radon in mines and in building material - atomic bomb explosion - chemo­ therapy - dioxin and related compounds.

Prostaglandin research is one of the most explosive fields in the biological science, and there have been a number of international symposia on this subject. In planning the second Advanced Course in Erice (Sicily) at the "Ettore Majorana" center it was realized that large congresses might not represent the best way to facilitate communication within specialized areas of biologic and medical research. In fact small meetings where in depth discussion is confined to a limited number of scientists, are now generally considered successful vehicles of scientific information. With this in mind, we made an effort in collecting a number of experts in both experimental and clinical use of these important arachidonate metabolites. We have been very fortunate in bringing together a faculty of international authorities who contributed to the course with brilliant presentations and lively discussion. Thus, this book represents an up-to-date overview of the physiology and pharmacology of different products derived from arachidonic acid metabolism, associated with outstanding suggestions of their clinical potential. It is our hope that from this Advanced Course, and its resulting publication, new ideas concerning the physio­ pathological role of these compounds will arise together with new directions for future research. We are deeply indebted to NATO for its interest and generous support which made this Second Course a reality.

The physiological role of histamine in gastric secretion has been controversial since Popielski demonstrated that histamine sti- mulates this secretion. The results using H2-receptor antagonists, together with the findings that histamine is produced and stored in the fundic mucosa and released upon vagal or hormonal stimulation, indicate that this amine is the major physiological stimulant of the parietal cells. The concepts of histamine as a 'final common chemo- stimulator' of parietal cells, and as part of a 'multi-messenger' potentiating interaction of various hormonal secretagogues on parietal cells, have both been proposed to explain the involvement of hista- mine in gastric secretory mechanisms. Histamine may also be an im- portant factor in the pathogenesis of gastric hypersecretion and peptic ulcer disease since its mobilization from gastric mucosal stores is accelerated in peptic ulcer disease, and since treatment with vagotomy or H2-receptor antagonists decreases histamine release and increases its degradation in the gastric mucosa. REFERENCES Angus, J. A., 1982, Histamine receptors - their classification and role in gastric acid secretion, in: Receptor Update; Proceedings. Excerpta Medica, Geneva, 29. Angus, J. A. , and Black, J. W. , 1978, Production of acid secretion in the isolated stomach by electrical field stimulation, Br. J. Pharmacal. 62: 460P. Angus, J. A. , and Black, J. W. , 1982, The interaction of choline esters, vagal stimulation and H2-receptor blockade on acid secretion in vitro, Eur. J. Pharmacal. 80: 217. Ash, A. S. F. , and Schild, H. O.

Thirteen years have gone by since the first international meet­ ing on Animal Sonar Systems was held in Frascati, Italy, in 1966. Since that time, almost 900 papers have been published on its theme. The first symposium was vital as it was the starting point for new research lines whose goal was to design and develop technological systems with properties approaching optimal biological systems. There have been highly significant developments since then in all domains related to biological sonar systems and in their appli­ cations to the engineering field. The time had therefore come for a multidisciplinary integration of the information gathered, not only on the evolution of systems used in animal echolocation, but on systems theory, behavior and neurobiology, signal-to-noise ratio, masking, signal processing, and measures observed in certain species against animal sonar systems. Modern electronics technology and systems theory which have been developed only since 1974 now allow designing sophisticated sonar and radar systems applying principles derived from biological systems. At the time of the Frascati meeting, integrated circuits and technol­ ogies exploiting computer science were not well enough developed to yield advantages now possible through use of real-time analysis, leading to, among other things, a definition of target temporal char­ acteristics, as biological sonar systems are able to do. All of these new technical developments necessitate close co­ operation between engineers and biologists within the framework of new experiments which have been designed, particularly in the past five years.

The function of the vascular system is to transport oxygen and nutrients to the cells and to remove carbon dioxide and metabolites. It also transports hormones and locally produced neurohumoral substances which, in part, regulate its own function. These interrelationships are essential to homeostasis. The vascular system is not an assembly of simple (elastic) tubes but a dynamic system with many external and intrinsic regulatory mechanisms. The endothelium plays a major role in the intrinsic regulation of the system. The system is also often subject to disease processes of which atherosclerosis is the most important. As a result of atherosclerosis, and other disease processes, replacement of vessels with prosthetic devices may be required to reestablish adequate tissue blood flow. It is therefore imperative to gain insight into the details of vascular function, especially the dynamics, and the endothelium, the processes of atherosclerosis development, the vascular prosthetic possibilities and, last but not least, the interrelationships between these sub-specialties.