Howard B. Andervont

Effect of Testosterone Propionate on Development and Growth of Mammary Carcinoma in Female Mice.

Estrogen, when administered to male mice of certain strains, will result in the appearance of spontaneous mammary carcinoma. 1 , 2 , 3 The females of these strains ordinarily have a high incidence of spontaneous mammary carcinomas, which do not normally occur in the males. It has further been demonstrated that the incidence can be increased and the time of appearance of the mammary carcinoma hastened by the administration of estrogen to the females of these same strains. 4 Recently, Lacassagne 5 tested the effect of testosterone upon development of mammary carcinoma in females of a high incidence strain and noted no alteration from the controls. The dosages used, however, were small. It is the purpose of this communication to report the results of long term injections of testosterone propionate∗ upon subsequent development and growth of spontaneous mammary tumors in female mice with an extremely high incidence (95%). 6 Forty female mice of the C3H strain, born at approximately the same time, were kept under similar experimental conditions. They were then bred at maturity and all except 2 animals had their litters within several weeks of each other. The remaining 2 animals had litters one month after the first of the entire group. The litters were killed within 24 hours after birth and the animals were then divided into 2 groups of 20. For every animal in one group, there was a sister litter mate in the other. At the age of 4 1/2 months, injections of testosterone propionate in sesame oil were given to one group of 20, dosage 0.5 mg in 0.05 cc of oil 3 times weekly for a period of 4 months.

Relation Between Latent Period and Growth Rate in Chemically Induced Tumors

Summary There is a high degree of correlation between the malignancy of chemically induced tumors, as measured by growth rate and mitotic index, and shortness of the latent period before appearance of palpable tumors. This relation holds true in the various responses of different strains of mice to the same agent, and in responses to different agents and modes of administration. It is suggested that the growth rate of a tumor in the microscopic stage is important and may be the main factor determining the latent period in carcinogenesis.

The Relation Between the Virus of Epithelioma Contagiosum and the Vaccine Virus.

As the result of a recent study of the relationship existing between the virus of epithelioma contagiosum and the vaccine virus, the author concludes that while the vaccine virus is definitely pathogenic for the fowl, the epithelioma contagiosum virus is only mildly pathogenic for the rabbit. The lesions which the vaccine virus evokes in the fowl are characteristic of vaccinia, while those which the epithelioma contagiosum virus produces in the rabbit, are not specific. While the vaccine virus will give rise to the formation of typical Guarnieri bodies both in the skin and in the cornea of the inoculated fowl, the epithelioma contagiosum virus produces no Bollinger bodies in either the skin or the cornea of the inoculated rabbit. It is especially noteworthy that the fowls skin and cornea are capable of producing both Guarnieri and Bollinger bodies and that they respond to the introduction of the two viruses in question in a perfectly specific manner. Fowls develop a definite and specific immunity to both the virus of epithelioma contagiosum and to the vaccine virus, but a preliminary infection with either does not protect against a subsequent infection with the other. A preliminary inoculation of the rabbit with the epithelioma contagiosum virus will similarly not protect the animal against a subsequent infection with the vaccine virus, and a previous infection with the vaccine virus is without effect against the slight response which the rabbit may normally offer to the epithelioma virus. The authors results support the claims of Loewenthal and his coworkers 1 regarding the lack of identity or even of a close relationship between the vaccine virus and the virus of epithelioma contctgiosulm, and stand in opposition to those of Van Heelsbergen 2 and Toyoda. 3