Clinical Analysis of Axis Fracture

This retrospective analysis describes the clinical characteristics, treatment, and long-term outcome of 30 patients with axis fracture admitted to our institution between January 1991 and December 1995. The incidence of axis fracture was 27.2% in the 110 cervical spine fractures. Among these, odontoid process fracture was the most common type, 19 cases(63%) followed by 8 hangmans fractures(27%), 3 miscellaneous fractures(10%). Hangman's fractures, odontoid type III fractures and miscellaneous fractures were treated with external immobilization devices. Remaining 11 odontoid type II fractures, and six patients with dens dislocation of 6 mm or greater were initially treated by early surgical stabilization. Individuals with dens dislocated less than 6 mm were treated by external immobilization only. Among the nonoperative group of acute axis fractures, there was no fusion failure. In the early operated group, all patients were stable clinically or radiologically. But three patients with posterior wiring and bone graft complained of their neck motion limitation.

Contractile and Inhibitory Effects of McN-A-343 and Acetylcholine on Isolated Arteries

Effect of acetylcholine(ACh) and McN-A-343 on porcine coronary artery and rabbit thoracic aorta were investigated in isolated preparations with or without intact endothelium. In the porcine coronary artery, ACh produced concentration dependent contraction which was greater in rings without the endothelium than in intact endothelial rings, but McN-A-343 did not alter the basel tension in both tissues. ACh relaxed contraction induced by 5-hydroxytryptamine(5-HT) in only intact endothelial rings, while NcN-A-343 inhibited the 5-HT induced tension in both preparations dose dependently. Carbachol elicited a prominent contraction in both tissues. The carbacol-induced tension was markedly inhibited by McN-A-343 in either rings with or without endothelium, while ACh contracted further the tension. ACh and McN-A-343 did not after the KCi induced tension, but clearly potentiated the contraction induced by Bay K 8644 in intact endothelial rings. In rabbit thoracic aorta, ACh elicited contraction in a concentration-dependent fashion which was potentiated by removal of endothelium, but McN-A-343 did not affect the basal tension of both rings. ACh inhibited the 5-HT-induced contraction in only intact endothelial ring, but McN-A-343 did not change the contraction of both rings. Conclusively, ACh produces endothelium-dependent relaxation in both arteries, while McN-A-343 elevated endothelium-independent inhibition to 5-HT or carbachol-induced tension.