The contrast in the reactions to the implantation of cancer after the inoculation of living and mechanically disintegrated cells

Abstract

The object of the present paper is to show the difference obtaining between the employment of the living cell, cancerous and normal, as an agent to induce active resistance to the implantation of cancer cells, and the employment for the same purpose of the protein obtained from these cells by mechanically disintegrating them. As a means of devitalising the cells with least disturbance of their chemical properties, the method adopted was that of grinding them either in the MacFayden-Rowland apparatus at the temperature of liquid air, or in a mortar, cooled by embedding it in ice and salt. Comparison of the results obtained by both methods showed that the latter was the more efficacious. By interrupting the freezing, the material can be kept of a pasty consistence specially favourable for crushing all the cells. The completeness of the disintegration of the cells was ascertained by microscopic examination, revealing the absence of intact nuclei, and, in the case of the caner tissue, also by inoculation of the material not yielding tumours. Every precaution has been taken to employ mice as uniform in age, size, and weight as possible, in order to make the estimations upon a soil of uniform natural resistance. In order to analyse the results more closely in each experiment, the animals were killed after the same interval of time, when the tumours threatened to ulcerate, and all the tumours obtained were weighed. The protocol of such an experiment is given, showing all the details of the experiment, including: (1) The length of time elapsed between inoculation and the date when mice were killed; (2) number of tumour mice alive up till then; (3) total number of mice alive; (4) total weight of tumour obtained; and (5) average weight of mice. To obtain an estimate of the average growth, two calculations have been made: the one indicates the average weight of tumour obtained, calculated on all the animals of the series living up till the time when they were killed (negative include): ("average weight of tumours pro mouse"); the other gives the average weight of each tumour, when only the positive mice are takeninto account ("average weight of tumours pro tumour"). It seemed inadivsable to use the figures obtained for more elaborate calculations, because of the only approximate value of all such figures obtained by biological experiment. In all transferences of cancer cells, small factors, such as health of the animals, intercurrent diseases—factors which are incapable of exact measurement—play a very important part in determining the results.