A study of the preparation, localization, and effects of antitumor antibodies labeled with I131.

24, 29, 30). Furthermore, a specific type of local inflammatory response, which may indicate the development of spontaneous resistance to the neoplastic cells (13, 28), has been observed at the edge of some tumors. Antibodies to neoplastic tissue in one species can be produced in another. These antibodies can be demonstrated serologically (7, 11, 12) and, under some conditions, have been shown to alter the growth or appearance of neoplastic cells in vitro (5, 9, 10). There is little evidence, however, that the growth or structure of well established neoplastic cells can be altered in vivo by immuno logie methods. More recently, Pressman and co-workers (1621) have pioneered in demonstrating that a spe cific heterologous antiorgan or antitumor serum labeled with I131shows in vivolocalization (8, 20).