ESTABLISHMENT OF A MILK AGENT-FREE SUBSTRAIN C3HeB/Os AND EFFECT OF FOSTER NURSING ON OCCURRENCE OF MAMMARY TUMORS

Abstract

A substrain of C3HeB was established in this institute. This milk agent-flee but susceptible substrain developed spontaneous tumors, i.e. mammary tumors (2.1%), pulmonary adenomas (3.1%), abdominal lymphomas (6.2%), and ovarian cysts (2.1%) in females, and hepatomas (14.3%) and abdominal lymphomas (4.0%) in males. This subline was susceptible to the milk agent but did not pass it on to the offsprings.