Alfred Taylor

Application of a metabolic inhibitor to the developing chick embryo.

Summary 1. Embryonic chicks were inhibited by the direct injection of 3-acetylpyridine into the yolk-sac. 2. It was shown that this inhibition could be reversed competitively by nicotinamide over the range of 2000 to 7000 γ per egg. 3. Evidence is presented showing that 4-day-old chick embryos have a very limited capacity to convert nicotinic acid to the corresponding amide. 4. Sublethal levels of 3-acetylpyridine are shown to cause a mal-development of the chick embryo.

EFFECT OF SODIUM FLUORIDE ON TUMOR GROWTH.

Summary In 54 tests involving 991 mice bearing transplanted tumors and 58 tests including 1817 tumor-bearing eggs, data were obtained which indicated a statistically significant acceleration of tumor tissue growth in association with comparatively low levels of NaF.

Male mice tolerate dosages of pteroylglutamic acid lethal to females.

Summary and Conclusion Male mice are much more resistant than female mice to injections of high dosages of folic acid. Male mice were only slightly affected by single subdermal injections of 5 mg of folic acid. Female mice receiving the same dosage averaged a 10% loss in body weight followed by a slow recovery. There were no deaths in a group of male mice receiving 15 to 40 mg in a single injection of folic acid. The same dosages administered to female mice were rapidly lethal in every instance.

Inhibition of the Growth of Egg Cultivated Tumor Tissue by Extracts of Cooperia pedunculata Herb

Summary Extracts of Rain-lily bulbs have been tested for their effect on the growth of tumor and embryo of tumor-bearing eggs. The results obtained with aminopterin in the same tests are included for comparison. Acid aqueous and acetone extracts of the plant bulb inhibited tumor growth 81% and 94%, respectively, without affecting the embryo. Aminopterin inhibited tumor growth 87% and embryo growth 19%.

Egg Cultivated Tumor Protects Embryo against Vaccinia Virus

Summary 1. Yolk sac implants of a dba mouse mammary tumor protected the host embryos against vaccinia virus. A dosage of the virus which killed embryos of nontumor-bearing eggs in 3-4 days gave no evidence of toxicity in the embryos bearing the dba tumor 7 days after inoculation. Tests demonstrated that the virus was present in the fluids of these embryos. 2. Comparable tests with eggs bearing a C3H mammary tumor indicated the embryos were only slightly protected against the virus, and yolk sac implants of a rat sarcoma gave negative results in this respect. 3. None of the 3 tumors affected the toxicity of a strain of influenza. 4. It is suggested that the dba tumors protective effect on the embryos was due to the neutralization of the vaccinia virus by the tumor agent.

Temperature level and the growth of embryo and tumor of tumor-bearing eggs.

The technique of growing tumor tissue in embryonated eggs has been routine in this laboratory for more than 4 years. The use of the yolk sac method of inoculation has made it comparatively simple to maintain rat and mouse tumors indefinitely by egg to egg inoculations. 1 , 2 The size of the tumors grown in this manner were of the same order as those obtained by transplant in the host animal. This continued to be so after as much as 114 transplant-generations or about 4 years continuously in eggs. Apparently the egg environment satisfies all the requirements of malignant tissue for vigorous growth. The inoculation of eggs through the yolk sac results in tumor implantation on the yolk sac inner wall. 3 In this situation the growth of the tumor presents a minimum of interference with the development of the chick embryo. Tumor tissue and chick tissue grow together sharing a common blood supply. It is not uncommon for the egg-grown tumor to weigh as much as 6 g at the 17 th day of egg incubation, while the chick embyro normally weighing about 20 g at this stage is reduced to 10 or 12 g. The egg environment is relatively stable but a certain amount of manipulation will be tolerated by the chick embryo. This is especially so with respect to temperature. Incubating eggs will withstand considerable variation in temperature and still survive to the 17-18 day period. The present paper is concerned with a study of the comparative reactions of tumor and chick tissues grown together to temperatures above and below that required for normal incubation. Experimental. Embryonated eggs on the 4th day of incubation were inoculated with dba mouse mammary carcinoma. The eggs of one series of inoculations were divided into 3 groups and incubated from the time of implantation until the termination of the experiment at 3 different temperatures. One group representing the control was kept at 99-100° F, a second group was incubated at 96-97°F, and the third group was maintained at a temperature of 103-104°F. At the 18th day of incubation, or 14 days after tumor inoculation, the embryos and tumors of the surviving eggs were harvested and weighed.

Protective Effect of Symphytum officiale on Mice Bearing Spontaneous and Transplant Tumors

Summary A cold water extract of leaves of the plant Symphytum officiale was given to mice bearing spontaneous or transplanted tumors. The tests involved 73 control and 52 experimental mice bearing spontaneous mammary tumors of various initial sizes, and 71 control and 63 experimental animals bearing transplanted mammary tumors. Survival time of the spontaneous tumor mice that received comfrey extract was increased an average of 59% as compared with the controls. In the transplanted tumor tests, tumor weight at autopsy averaged 24% less in the comfrey extract mice as compared with the controls. These differences between control and experimental groups are statistically significant.