Homografting
The possibility of successfully transplanting tissues from one human being to another has long been of interest to both clinicians and research workers. Up to this time, however, one may say that no adult tissue exists which can be successfully and permanently transplanted from one human being to another, preserving its normal structure and its original living cells. Two possible exceptions to this statement are the cells in homogenous grafts of cartilage and those in the interstitial portion of cornea. In both of these cases, however, the tissues are avascular, and the cells are protected by a muco-protein-like matrix, which prevents the entrance of hostile host cells.The generally accepted theory regarding the rejection of homografts is that of an actively acquired immunity. According to this concept, the homograft liberates some product which stimulates the formation of a specific antibody. This antibody causes destruction of the cells in the