Transplantation immunity and isograft size of spontaneous mammary carcinomata in mice

ABSTRACT

A method was described for determining the size of palpable mammary tumors in a mice without removing the tumor or killing the host. A formula was worked out and nomographs were made for simple and direct use employing only 2 diameters, bisecting the palpable growth at right angles to each other. Small tumor implants [0.05 to 5 cu mm in size] of C 3H spontaneous mammary carcinomas developed palpable tumors with same growth rates and same times of appearance in young syngeneic hosts of C 3H virgin females irrespective of the initial implant size. On the other hand, large implants [25 and 50 cu mm in size] of same carcinomas underwent necrosis and/or regression after an initial retarded growth and delayed appearance in syngeneic hosts.However, animals with regressing tumors from large implants remained refractory to a second challenge implant [0.5 cu mm in size], those with progressing growing tumors from small implants developed large tumors at challenge site.Resistance to challenge implants apparently immunologic in nature could be passively transferred to normal syngeneic hosts by lymph node cells and peritoneal washing cells