Cross-clamping of the thoracic aorta. Influence of aortic shunts, laminectomy, papaverine, calcium channel blocker, allopurinol and superoxide dismutase on spinal cord blood flow and paraplegia in baboons. - Svensson,L.G.; von Ritter,C.M.; Groeneveld,H.T. (Ann Surg, 1986)