Excited States And Free Radicals In Biology And Medicine

Excited states and free radicals are involved in the normal physiology of living systems, in pathological processes (including lipid peroxidation, inflammation, Parkinson's disease, cancer, and aging), in the mechanisms of drug action, and in the photochemotherapies such as the PUVA therapy for skin diseases and PDT for cancer. This text introduces the reader to this rapidly expanding field, one that lies at the borderlines of physics, chemistry, biology, pharmacology, and medicine. The authors explore in particular how time-resolved spectroscopic methods have found solutions at the molecular level to biological and medical problems. Topics include the nature of excited states and free radicals and the techniques for their study, activated oxygen species, DNA, proteins, carotenoids and photosynthetic reaction centers, photodermatology and melanogenesis, and aspects of cancer related to radio-, chemo-, and photodynamic therapy. Researchers and graduate students in photochemistry, photobiology, photomedicine, radiation chemistry and biology, and cancer therapies will find this book to be of very significant interest.

Free Radicals in Biology and Medicine has become a classic text in the field of free radical and antioxidant research. Now in its fifth edition, the book has been comprehensively rewritten and updated whilst maintaining the clarity of its predecessors. Two new chapters discuss 'in vivo' and 'dietary' antioxidants, the first emphasising the role of peroxiredoxins and integrated defence mechanisms which allow useful roles for ROS, and the second containing new information on the role of fruits, vegetables, and vitamins in health and disease. This new edition also contains expanded coverage of the mechanisms of oxidative damage to lipids, DNA, and proteins (and the repair of such damage), and the roles played by reactive species in signal transduction, cell survival, death, human reproduction, defence mechanisms of animals and plants against pathogens, and other important biological events. The methodologies available to measure reactive species and oxidative damage (and their potential pitfalls) have been fully updated, as have the topics of phagocyte ROS production, NADPH oxidase enzymes, and toxicology. There is a detailed and critical evaluation of the role of free radicals and other reactive species in human diseases, especially cancer, cardiovascular, chronic inflammatory and neurodegenerative diseases. New aspects of ageing are discussed in the context of the free radical theory of ageing. This book is recommended as a comprehensive introduction to the field for students, educators, clinicians, and researchers. It will also be an invaluable companion to all those interested in the role of free radicals in the life and biomedical sciences.

Although free radicals perform some useful immune functions, they can also damage healthy cells through a process called oxidation. Antioxidants reduce the effect of free radicals by binding together with these harmful molecules, decreasing their destructive power. This book highlights various issues of free radical biology from the perspective of antioxidant defense mechanisms. It also provides useful information on gene modulation, radiation-generated reactive oxygen species-induced apoptosis in cancer, and environmental aspects associated with free radicals’ exposure on living systems.

This book is based on the papers presented at the "Fourth International Congress on Oxygen Radicals (4-ICOR)," held June 27 - July 3, 1987, at the University of California, La Jolla. The chapters deal with the phenomena associated with highly reactive oxygen species (hydroxy, peroxy, alkoxy, aroxy, and superoxide radicals, as well as singlet oxygen) and their peroxidation products (hydrogen peroxide, hydroperoxides, peroxides, and epoxides) as they relate to the fields of chemistry, food technology, nutrition, biology, pharmacology, and medicine. The kinetics, energetics, and mechanistic aspects of the reactions of these species and the interrelationship of oxygen radicals (or any other free radicals) and peroxidized products have been emphasized. Special attention is focused on the mechanisms of the generation of free radicals and peroxy products in biosystems and on the adverse effects of these radicals and products in humans. The topics span the continuum from the simple chemistry of model systems to the complex considerations of clinical medicine. The book also explores the mechanisms of agents that protect against free radicals and peroxy products in vitro and in vivo. These agents include antioxidants used in materials, food antioxidants, physiological antioxidants, and antioxienzymes (SOD, glutathione peroxidase, and catalases). The use of these inhibitors to prevent damage to organs being prepared for transplantation, thereby maintaining the quality of transplanted organs and/or extending their "shelf-life," also is examined.

Focuses on the pivotal roles of reactive oxygen and nitrogen species (ROS and RNS) in the pathogenesis of many clinical conditions (together with their involvement in the ageing process of lower (yeast) cells, and higher organisms including plants). This book also discusses the potential applications of dietary-derived antioxidants.

This concise monograph describes a variety of important reactions of iron in biological free-radical reactions. It presents both a chemical and a biochemical perspective of the topic, but at the same time unifies ideas where possible. Iron plays a key role in biological life processes, as acatalayst enabling us to use oxygen to generate the heat and chemical energy that drives life. When iron is not properly controlled within the body it can cause damage by making free radicals. The authors present a chemical and biomedical perspective of how reactions of iron complexes and freeradicals may contribute to human health and disease, especially in reactions of oxygen and hydrogen peroxide.