was unjustified, they favoured the view that the presence of a nidus of necrotic cartilage was essential. Again, Goldhaft, Wright, and Pemberton claimed confirmation of the work of Wollenberg. Degenerative and hypertrophic changes followed the occlusion of the patellar blood supply Danusertib PHA-739358 in dogs. Walkhoff Ewald, and Preiser repeated the same work in dogs and rabbits but with negative results. Goldhaft, Wright, and Pemberton, in further studies, showed, not surprisingly, that the response of dogs to such procedures was conditioned by their maturity. Finally, Bennett and Bauer repeated these experiments yet again, this time with convincingly positive results. COMEWNT Physical agents damaging to joints have been used experimentally to produce forms of arthritis which most frequently resemble degenerative joint disease in the human.
There is no evidence that such methods lead to changes which by their nature or disposition resemble those of rheumatoid Gefitinib arthritis. The future elucidation of the nature and cause of rheumatoid arthritis is unlikely to result from methods of the kind mentioned in this section. Summary The cause of rheumatoid arthritis is not known. One of the reasons for this lack of understanding may be the absence of a true experimental replica of the disease. As part of an approach to this problem, a review has been made of the principal methods which have been described for producing arthritis experimentally. The methods, considered chronologically, have been divided for convenience into five groups: infective, chemical, endocrinological, immunological, and physical.
The conclusion is reached that none of the forms of experimental arthritis at present known bears more than a superficial similarity to rheumatoid arthritis in the human. It appears possible that this disease may be confined to man or to the primates. The suggestion is made that our understanding of the aetiology and pathogenesis of rheumatoid arthritis may be better advanced by a concentration of experiment on the organ and tissue responses in man and the anthropoid apes, than by a dissipation of effort on the laboratory study of arthritis induced in small rodents. THE INFLUENCE of ultraviolet irradiation of the operating room on the incidence of postoperative wound infection was investigated by means of a double blind, randomized study in five institutions.
Over a two year period, 14,854 operations and 15,613 incisions were studied in relation to postoperative wound infection. Although ultraviolet irradiation reduced the number of airborne bacteria in the operating room, the wound infection rate in the entire series following operation was 7.4 per cent in irradiated rooms and 7.5 per cent in unirradiated rooms. The only category of wounds that benefited significantly from the use of ultraviolet radiation was the refined clean group, in which the postoperative infection rate was reduced from 3.8 to 2.9 per cent. Even this beneficial effect, which was confined to a category representing only 19.2 per cent of all infections analyzed, was lost in the over all experience, offset by an apparent detrimental effect of irradiation in nonclean wounds. The over all infection rates at each of the five participating hospitals varied from a l