Small Initial Doses Research Articles

A Study of the Athreptic Theory of the Growth of Cancer

In 1904 Bashford and Murray (1) showed that tumor transplantation could be successfully performed in mice in which Jensen mouse carcinoma had already developed fourteen days to ten weeks after the first effective transplantation. Two years later Ehrlich (2) reported that the presence of actively growing transplanted mouse carcinoma or sarcoma prevented the growth of secondary implants in a majority of cases. He explained this by assuming that special nutritive substances are required for the growth of neoplastic cells and that these cells take up such food stuffs more rapidly than do normal somatic cells. The limited amount of growth-promoting substances is all taken up by the first implant, thus preventing the development of the secondary implant. From this observation Ehrlich declared his athreptic theory of the growth of cancer. Later Bashford, Murray and Haaland (3) suggested that the degree of resistance of the host to the secondary implantation depends upon the degree of resorption of the first tumor tissue implants. Thus the percentage of the positive reinoculations in animals which received a larger initial dose is much less than those which received a smaller initial dose, because in the latter case less tumor material was reabsorbed than in the former. Where the initial dose for each animal was the same, animals with the more slowly growing tumors have a higher grade of resistance than animals with actively growing tumors, presumably because the animals carrying smaller tumors had re-absorbed a larger amount of tumor tissue than had those with larger tumors.

Bacteriological Research in Bombay

THE report of the Bombay Bacteriological Laboratory for the year 1914, by Major W. Glen Liston, reached this country recently. The report is divided into two parts: (i) that dealing with plague work, and (2) that dealing with general preventive medicine. Statistics are furnished which tend to show that the uninoculated are attacked three times more frequently than the inoculated (against plague). One drawback to the use of plague vaccines is the severe reaction which follows, deterring others from undergoing the operation. It is now suggested, as results of experiments on rats and observations on man, that a small initial dose of 1–2 c.c. should be given, to be followed in a week by a second dose of 2–4 c.c. It appears that there are two other species of fleas of the genus Xenopsylla—viz., X. brasiliensis and X. astia—besides the originally known species X. cheopis, which, however, forms 80 per cent, of the three species concerned. Whether they all transmit plague is a question which must arise. The results of the examination of rats in the laboratory show that both in the case of M. rattus and M. decumanus there is a rise above the mean in the rate of infection in the latter half of January, whereas the rise above the mean in human plague mortality occurs in the first half of March. The fall below the mean occurs at the same time for both species of rats and for man—viz., in the first half of June. The summit of the infection for M. rattus precedes that of M. decumanus by a fortnight, while the infection of the latter and the mortality in man reach their maximum at the same time—viz., in the latter half of April.