"Oxidative stress" is used as the generic term describing the involve ment of reactive oxygen species in various human diseases. The scope of such a topic is becoming increasingly wide. The recent interest in radicals such as nitric oxide and the discovery of new mechanisms such as the effect of free radicals on redox sensitive proteins and genes are enlarging our understanding of the physiological role of free radicals. Oxidative stress is involved in numerous pathological. processes such as ageing, respiratory or cardiovascular diseases, cancer, neurological pathologies such as dementia or Parkinson's disease. It still remains difficult, however, to demonstrate by chemical measurement the in vivo production of free radicals and even more to realise their speciation. Therefore, the development of new tools and indicators is engrossing many researchers working in this field. Reliable indicators are abso lutely necessary not only to monitor the evolution of oxidative stress in patients but also to evaluate the efficiency of new antioxidant treat ments. The French Free radical club of Grenoble, the CERLIB has been involved for many years in the organisation of international training programs on methodology, in order to provide both theoretical and practical help to researchers from various countries. Such training sessions have been highly successful and participants value the oppor tunity to learn reliable techniques. This positive echo explains why the researchers of CERLIB decided, with the help of Prof. Dr. B. Kalyanaraman, to publish selected techniques on free radical re search."

This publication presents the culmination of collaborative effort between specialists in the wide range of disciplines concerned with the effects of ionizing radiations on nucleic acids. The authors belong to a group formed under the aegis of the Com mission of the European Communities some eight years ago with the object of facilitating the exchange of ideas and inforrration between European scientists working in this field. The Commission'S aim was not to replace traditional information channels, but to strengthen the various links between the scien tists in the group, as if they were working together in a single team. In addition to the annual meetings of the group, contact was maintained by individual visits, exchanges of young scientists, experiments using mutual equipment, and the regular publication of a Newsletter, mainly to announce the availability of preprints. Bruxelles, December 1977 A. J. Bertinchamps Commission of the European Communities. Preface Mankind today is faced with a choice of cardinal importance, namely, deciding on the source and quantity of energy to be made available for tomorrow's world. If, as is probable, the energy is to be mainly of nuclear origin, we must expect a marked ex pansion of the nuclear industry, which could well become the world's leading industry in the not-too-distant future. This would carry with it the problems caused by the presence of enor mous quantities of radioactivity, despite the stringent precau tions taken to date and those to be taken in future."