Hygiene

Two recent papers help to shed a little further light on this problem. H. E. Holling, R. S. Brodey and H. C. Bolandhave studied the problem both in man and in the dog. Earlier work has shown that in man osteoarthropathy may be associated with an increased bloodtlow in the limbs, and this is also the case in the dog. By means of cross-circulation experiments between the limb of a normal dog and one with osteoarthropathy, Holling, Brodey and Boland were able to show that blood-flow was not signitlcantly affected in either limb. This would suggest that humoral factors are not implicated in the pathogenesis of osteoarthropathy. In man regression of osteoarthropathy has followed removal of the primary lung lesion, exploratory thoracotomy or unilateral vagotomy, and this is associated with prompt reduction of the increased blood-tlow, followed by resolution of the soft tissue overgrowth, and some weeks later by the regression of the bony changes. The work ot these investigators suggests that the blood·tlow is maintained by a retlex with afferent tlbres in the vagus nerves, though the efferent pathway of this retlex remains undetermined.