1) In the suspension medium buffered with sodium hydrogencarbonate, addition of glucose causes a rapid fall of respiration (Crabtree effect) in Ehrlich tumor cells. This suppressed respiration, however, begins to be restored after about 30 to 40 minutes of incubation period and proceeds increasingly beyond the level of endogenous respiration.
2) Indifferent to this unstable respiration, the respiration quotient value which is greater than unity is steadily sustained so long as glucose remains, in contrast to that of endogenous metabolism which is of the order of 0.7.
3) The modified pattern of the Crabtree effect is almost reproducible irrespective of different stages of tumor growth. Thus, the facts presented in the preceding report are now fully confirmed.
4) In the presence of sodium hydrogencarbonate, aerobic glycolysis shows a rapid and linear rate during the whole period of incubation.
5) A marked rise of glycolytic activity in tumor cells and at the same time a pronounced loss of carcass weight in host occur abruptly at about 10 days after implantation. The synchronous occurrence of these two phenomena indicates that there is an intimate metabolic relationship between tumor and host, and that the tumor-host relationship as a process can be resolved at least into two phases, initial and latter.

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The effect of subcutaneous inoculation of polyoma virus into the submandibular and dorsal regions of newborn DDO mice within 24 hours after birth was investigated in order to test specific susceptibility of that region or of the mice themselves to the virus, and following points were found.
1) Seventy-six percent of those receiving submandibular inoculations of polyoma virus developed tumor. The mean age for the appearance of the tumor was from 2 to 6 months.
2) Thirty-nine neoplasms developed among 26 mice. They were divided into 6 distinct types: 24 parotid gland tumor: 5 submandibular gland tumor: 4 sublingual gland tumor; 3 osteofibroma in the leg; 2 papillary adenocarcinoma in the mammary gland; and one osteofibroma in the mandible.
3) None of the mice that received the control material (tissue culture preparation without polyoma virus) in the submandibular region developed neoplasms.
4) The animals inoculated with polyoma virus in the back remained free of gross neoplasms during a 7-month observation period, although they did show histopathological changes in the kidney.
5) The mice which received the control material in the back did not develop any gross tumor or histopathological changes.
6) The present experiment indicates that the oncogenic effect of polyoma virus is local rather than systemic and that polyoma virus has special influence on salivary gland tissue without intermediation of other organs. Furthermore, DDO mice exhibited no specific susceptibility to polyoma virus.

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Histochemical demonstration of various enzymes in salivary gland tumor induced by polyoma virus in DDO mice was carried out.
Alkaline phosphatase activity was limited in the reticular and sarcomatous structures, e.g., interstitial non-epithelial elements showed a striking activity. Enzyme activity was not seen in the glandular epithelium. Acid phosphatase and esterase activity was lower than in normal glands, but acid phosphatase in the glandular structures of pleomorphic tumors revealed less activity than in sarcomatous cells. β-Glucuronidase activity was present in the epithelial-like components of glandular-type tumor and other tumor elements showed low activity. Aminopeptidase activity was hardly observed in this tumor. Succinic, malic, and lactic dehydrogenase activities were observed slightly in the tumor cells. In general, dehydrogenase activity was high in the duct epithelium of normal gland but was much lower in the pleomorphic tumor.

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The treatment of tumor cells with Tween 80 in vitro induced an increase of natural sensitivity of rat ascites hepatoma to nitrogen mustard N-oxide (HN₂-O), which was estimated from the minimum effective dose of HN₂-O, determined by the development of abnormal mitotic figure. This increased sensitivity returned rapidly to the original value within 6 hours in vivo showing that no hereditary factor was involved in the change. This phenomenon, however, could not be seen in sublines of Yoshida sarcoma and rat ascites hepatomas with acquired resistance.
The increase of the HN₂-O sensitivity was assumed to be induced by the increased permeability of the membrane of tumor cells by Tween 80, which was proved by the comparative estimation of the total content of SH radical of tumor cells before and after contact with HN₂-O in vitro. It was therefore concluded that the impairment of transportation of HN₂-O through cellular membrane participates to some degree in the natural resistance of rat ascites hepatoma cells to HN₂-O.

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The studies described in this paper are concerned with the effect of a semi-synthetic basal diet containing DL-ethionine, thioacetamide, or α-naphthyl isothiocyanate on reticuloendothelial system activity and quantitative histology of rats. The functional activity of reticuloendothelial system of each rat was determined by the Congo Red index. Histological examination used was the same as the previous method.
The above three substances were found to cause severe disturbances in the functional activity of the reticuloendothelial system. However, the functional activity of the reticuloendothelial system recovered markedly later on α-naphthyl isothiocyanate diet. The present results indicate some relationship to exist between the Congo Red index and the proliferation of connective tissue elements and bile duct cells. However, there was no apparent relationship between the Congo Red index and the percentage of PAS-positive reticuloendothelial cells.

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The histogenesis of ear-duct and liver cancers by means of DAS-feeding and the effect for the development of liver cancer with various short periods of DAB-feeding followed by DAS-feeding were studied. Results so far obtained were as follows:
1) Although feeding of 0.005% DAS ad libitum showed relatively toxic effect to the rat liver, it was demonstrated that DAS has a strong carcinogenic effect to develop ear-duct cancer in the rat. The effect of DAS on the epidermis of ear duct seemed to be its direct proliferation and not a regenerating one.
2) Besides the strong carcinogenic activity to ear-duct epidermis, DAS caused the development of liver as well as mammary cancers in the rat, but their incidence was very low.
3) Feeding of DAB for various short periods was followed by DAS-feeding for 5 months and in these DAB-DAS groups, the incidence of liver cancer was the same as or much higher than those of the group of DAB-feeding alone for 5 months. However, the latent period to develop the liver cancer was longer and the average number of the tumor nodules developed in the liver in each rat was smaller in DAB-DAS group than in DAB group.
4) The average number of tumor nodules in the liver and the frequency of metastatic growth in the lungs of the induced tumors were proportional to the period of DAB-feeding.
On the basis of these results, the histogenesis of ear-duct and liver cancers as well as the effect of combined application of DAB and DAS for the development of liver cancers was discussed.

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In the present series of experiments, various periods of MC-painting or DAS-feeding was followed by various periods of DAB-feeding up to five months and the surviving rats were kept under observation without any treatment for additional seven months. The development of liver and/or ear-duct cancer was examined, especially taking into consideration the pathohistological pattern of the induced tumors, and comparison was made between various groups. The results so far obtained were as follows:
1) Slight retarding effect on liver tumor incidence was observed when MC-painting was made for 2 months, followed by 3 months of DAB-feeding. This effect did not appear in the group which received 1 month of MC-painting followed by 4 months of DAB-feeding.
2) The average number of tumor nodules which developed in each rat was larger and the latent period for the tumor development was shorter in MC-treated groups than their control groups and they were also proportional to the period of DAB-feeding.
3) DAB accelerated the increase of ear-duct cancer in the rats which initially received DAS-feeding for more than 3 months.
4) The development of liver cancer was slightly increased by initial DAS-feeding for 1-2 months followed by 3-4 months of DAB-feeding compared with that of control group which received continuous DAS-feeding for 5 months.
Based on these results and those of the previous experiments, the carcinogenic actions of DAB, DAS, and MC on the rat liver as well as ear duct were investigated and discussed.

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The development of skin tumors was studied on the rats which received MC-painting for 1-5 months, followed by an interval of 7-11 months without any treatment, and then feeding of DAS for 5 months. Results obtained were as follows:
1) In all the animals given MC-painting for 4-5 months, skin tumor alone was produced.
2) Skin cancer development was found even in the rats which received MC-painting only 8 times during the first 1 month, followed by an interval of 11 months without treatment, and then DAS-feeding for the next 5 months.
Based on these results, the carcinogenic actions of MC and DAS were investigated and discussed in relation to the development of skin cancer in rats.

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Quantitative and qualitative analyses were carried out on visible mucus of gastric juice from patients with various disorders of the stomach, especially with carcinoma of the stomach. Volumetric determinations of visible mucus indicate pathological changes of surface epithelium by detecting abberations from normal range. Gastritis was characterized by wider range of deviation. A marked increase in sialic acid content was noted in partial hydrolyzate of the visible mucus of gastric carcinoma. Characteristic changes during disease were noted in increased viscosity at the isoelectric point of the visible mucus. Mechanisms of these phenomena are discussed in connection with patho-physiological functions of the visible mucus.

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