The editor of this volume, having research interests in the field of ROS production and the damage to cellular systems, has identified a number of enzymes showing OH scavenging activities details of which are anticipated to be published in the near future as confirmatory experiments are awaited. It is hoped that the information presented in this book on NDs will stimulate both expert and novice researchers in the field with excellent overviews of the current status of research and pointers to future research goals. Clinicians, nurses as well as families and caregivers should also benefit from the material presented in handling and treating their specialised cases. Also the insights gained should be valuable for further understanding of the diseases at molecular levels and should lead to development of new biomarkers, novel diagnostic tools and more effective therapeutic drugs to treat the clinical problems raised by these devastating diseases.