Abstract
Summary
1. Parotid tumors or leukemia developed following inoculation of Ak extracts into newborn C3H mice. When extracts from induced C3H leukemias were inoculated into 105 newborn C3H mice (Bittner substrain), 25 (24%) developed leukemia, 12 (11%) parotid tumors, and 7 (7%) subcutaneous sarcomas. Of 296 newborn C3H mice inoculated with parotid tumor extracts, 24 (8%) developed leukemia, 21 (7%) parotid tumors, 15 (5%) subcutaneous sarcomas, 2 submaxillary gland tumors, and 2 medullary adrenal tumors. 2. Centrifuged extracts from normal C3H embryos were inoculated into 103 newborn C3H mice, and 3 developed parotid tumors. Of 9 newborn C3H mice inoculated with C57 Brown/cd embryo extracts, 1 developed parotid tumor. When centrifuged extracts prepared from normal C3H mammary glands were inoculated into 60 newborn C3H mice, 9 developed parotid tumors, and 5 subcutaneous sarcomas. Centrifuged pooled normal C3H(f) and C3H organ (liver, spleen, heart, kidney) extracts fresh, or preserved either by dry-freezing or in 50% glycerine, were inoculated into 74 newborn C3H mice, and 10 (14%) developed parotid tumors. 3. Physiological saline solution or sterile tryptophane broth inoculated into 62 newborn C3H mice, did not induce tumors or leukemia. 4. Ak mice may carry not only a leukemic, but also another oncogenic agent, the latter not pathogenic for its natural carrier. C3H mice may also carry such a masked agent. A blind transfer into a newborn susceptible (C3H) host may sufficiently increase its pathogenic potency to cause parotid tumors. The sarcomas may be caused by another, individually distinct, though biologically similar agent.
Get full access to this article
View all access options for this article.