Molecular motor proteins produce force for movement in an incredibly wide variety of cellular processes. This volume explores the extreme functional and structural diversity of molecular motors and presents methods relevant to each motor family. In addition, it describes techniques directed at motors that fall outside of the three characterized families: dynamin and F1ATPase.

The Neurosurgeons of Berlin are happy to welcome their colleagues from Germany and from foreign countries to our Annual Meeting, being held in this city once again after many years. The external appearance of the city may have changed in many respects since our winter meeting in 1965. This ist not the case, however, as concerns the outstanding quality of its cultural life. We hope that you take as much profit of it as possible. When choosing the scientific themes of this congress, we were led by the idea that problems should be discussed which are not dealt with at special symposia this year. Thus, the problems related to lumbar disc surgery and its complications were chosen as one main topic. This important chapter of neurosurgery worries (and not seldom depresses) us in our daily work. A joint statistic analysis has been made, for which we are indebted to the colleagues from the following university clinics: Essen, Freiburg, Graz, Hannover, Heidelberg, Kiel, Koln, Mainz, Wiirzburg, Berlin-Charlottenburg, Berlin Steglitz, of the Neurosurgical Department of the BG-U nfallklinik Frankfurt/Main, of the Neurosurgical Department Wagner-J auregg-Krankenhaus Linz, of the Neurosurgical Clinic of the Katharinen-Hospital Stuttgart, and of the Neurosurgical Clinic of the Stadt. Krankenhaus Berlin-N eukolln."

This volume contains the papers presented at the 26th Annual Meeting of the Deutsche Gesellschaft fUr Neurochirurgie, held in Heidelberg, Western Germany, on May 1-3,1975. Since at recent meetings of the German Neurosurgical Society central pathophysiological problems such as "central dysregulation" and "brain edema" had been discussed extensively, it seemed appropriate to choose another major area of cerebral patho- physiology for the meeting in Heidelberg. CEREBRAL HYPOXIA is, as LANGFITT once emphasized, "the final common denominator" of various cerebral lesions with which the neurosurgeon is confronted every day. Raised intracranial pressure, respiratory disorders and disturbances in systemic arterial blood pressure, etc. may lead, if not treated, to a focal or global lack of oxygen in the brain tissue. Anoxia finally results in cell death and thus in irreversible cerebral damage or even death. Main interest has therefore been focussed on disturbances in cerebral perfusion pressure ("ischemic hypoxia") and in arterial oxygenation ("hypoxic hypoxia"). The importance of cerebral autoregulatory mechanisms protecting the brain against tissue hypoxia, of patho- morphological alterations of the cerebral vessels (e. g. the "no-reflow-phenomenon") in the course of severe hypoxia, and of changes in brain metabolism have been discussed on a large scale. The organizing committee was particularly happy to have obtained internationally well-known scientists who presented their work in the field of cerebral hypoxia.

On this occasion we look back on 25 years of the Deutsche Gesellschaft fur Neuro chirurgie. They hold a great deal: founding and development of the society, comple tion and extension, communication between the individual members and contacts to other societies beyond our borders. They also stand for close co-operation with those who transfer their patients to u- the neurologists and specialists in internal medicine, the ophthalmologists and ear nose-and throat specialists as well as the general surgeons. This 25th annual meeting will deal with two examples of diseases that present common problems to the neurologist and to the neurosurgeon, namely meningiomas and multiple sclerosis. In view of their long histories often going back over many years, both of these lesions lead to diagnostic errors and indequate treatment. And yet it should be possible to recognize meningiomas at an early date and to initiate the only possible treatment, the operation, if all diagnostic measures are repeatedly carried out. The diagnosis MS, on the other hand, with the multiplicity of symptoms which are peculiar to this disease, should continue to be re-examined until every other lesion has been excluded with certainty. The increasing number of legal proceedings because of diagnostic and therapeutic measures as well as the doctor-patient talk preceding the written consent for these measures are further problems in need of discussion. For this reason, the topic "medical liability in special reference to the neurosurgeon" was chosen for this meeting. Many questions necessitate many answers."