1. From the Surgical Laboratory of Circulatory Research, Department D, Rigshospitalet and the Department of Clinical Physiology, Bispebjerb Hospital, Copenhagen, Denmark, the Cattedra de Chirurgia Vascolare, II Clinica Chirurgica dell'Universita di Roma, and I Clinica Mallattie Nervose e Mentali dell'Universita di Roma, Italy.