Mixture of 3, 4-benzopyrene and skin homogenate in aqueous solution was stirred for three days or more in a light-shielded glass flask and it was lyophilized. The sample gave ESR signal characteristic of a typical free radical with g=2.004, and greater parts of this free radical were diminished by degassing. Judging from the g-value, this free radical seems not to be peroxy radical, but rather seems to be a semiquinone radical. Possibility of photo-oxidation by room light during stirring and lyophilization was excluded by the fact that no difference was observed in the amount of free radical produced between the light-shielded samples and that of non-shielded samples. Dependence of the capacity for the free radical production in skin homogenates on the age of the mouse was tested using the skin homogenates of the newborn, 3-week-old, and 9-month-old mice. The skin homogenate of 9-month-old mice gave the most remarkable signal on stirring with 3, 4-benzopyrene. Among aromatic compounds tested, 3, 4-benzopyrene and 3-methylcholanthrene gave the free radical, whereas dibenz[a, c]anthracene, pyrene, phenanthrene, and Acridine Orange did not.
Mixture of protein with 3, 4-benzopyrene gave a similar signal as in the case of skin homogenate. Among the proteins tested, albumin and globulin gave a large amount of free radical, whereas DNase, RNase, chymotrypsin, and insulin gave lesser amount of the free radical. No free radical production was observed by stirring DNA or RNA with hydrocarbons.

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Effect of chondroitinsulfate and its components on the tumor growth was investigated, using solid Ehrlich ascites (hypotetraploid stock) tumor inoculated subcutaneously in SMA and ddN mice. One ml of various concentrations of test materials was injected subcutaneously into the back of mice, followed by tumor inoculation into the same site, and on the 8th day after tumor inoculation, average tumor weight in experimental group was compared with that in control group that received injection of saline.
2% D-Glucosamine hydrochloride, 0.2% D-glucuronic acid, and 0.2% N-acetyl-D-glucosamine accelerated the growth of tumor to some extent. The growth-promoting activity of these materials was not so marked compared with that of chondroitinsulfate solution, but chondroitinsulfate solution had no promoting activity on the tumor growth when hyaluronidase was added.
The effects of chondroitinsulfate and its components on the growth of tumor are briefly discussed.

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Animals given 2-(diacetamido)fluorene developed hyperplastic lesions and hepatocellular carcinomas. Hepatic lesions were transplanted subcutaneously, intramuscularly, or intrasplenically in autologous and isologous hosts, and intrahepatically or intraperitoneally in isologous hosts. Hyperplastic cells sometimes survived when transplanted intrahepatically and developed degenerative changes but did not grow on transplantation to any site. In isologous hosts, small welldifferentiated carcinomas grew only after intrahepatic transplantation. They grew better in male than in female animals. Small poorly differentiated and large highly, well, and poorly differentiated carcinomas grew in all sites. It is concluded that hyperplastic hepatic cells will not grow except in the site of origin in the liver in which they developed.

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The cytotoxic effect of 37 cardenolides, mainly extracted from Digitalis purpurea, were tested against HeLa-S₃ cells, with correlation to their cardiac activities. In general, the relative cytotoxicity of the cardenolides tested was found to parallel their cardiac activity. The cytotoxicity of cardenolides was not affected by cell age or the presence of bovine serum. The effect of cardenolides was observed as morphological changes in the culture such as clumping of the cells and subsequent detachment from the glass surface, but there were no observable differences in the ratio of mitotic figures between the cardenolide-treated and untreated control cultures. Neither did the treatment with cardenolide seem to affect the macromolecular synthesis of the HeLa-S₃ cells.
The mechanism of cytotoxic effect of the cardenolides was, therefore, suggested that the agents possibly act on the cell membrane per se rather than on the synthetic machinery of the cells. The cardenolides, though exhibiting high cytotoxicity against cultured cells, showed no antitumor effect whatsoever against Ehrlich ascites tumor in vivo.

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Impairment of antibody production following the administration of nitrogen mustard N-oxide could be protected by a photosensitizing cyanine dye. Pretreatment of the host with this dye inhibited the tumor take, whereas the host pretreated with nitrogen mustard N-oxide accelerated it. There was no effect on survival time of the host when the tumor cells were exposed to the dye in vitro before implantation. This dye itself had neither toxicity on the host nor reduction of effectiveness of chemotherapeutic agent in the experimental doses.

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Cell damages induced in the transplantable Donryu rat pulmonary carcinoma by X-irradiation of 3000R were investigated histochemically.
Non-irradiated tumor cells showed finely particulate reaction Products of acid phosphatase and β-glucuronidase in the Golgi region. After irradiation, they became diffuse and faint throughout the cytoplasm, through a transient increase of the activities at the Golgi region. The spontaneously degenerating tumor cells due probably to ischemia showed almost no changes in the localization pattern of the enzyme activities.
Reduced NAD dehydrogenase and succinate dehydrogenase activities showed no difference in the localization pattern in both irradiated and spontaneously degenerating tumor cells.
Radiation effects on the activities of acid hydrolases in tumor cells were discussed in relation to the enzyme release hypothesis.

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By intragastric instillation of 4-hydroxyaminoquinoline 1-oxide, neoplastic lesions of the glandular stomach were induced in mice. It was demonstrated that 4-hydroxyaminoquinoline 1-oxide in diluted ethanol solution induces adenocarcinomas only in the mucosa of the glandular portion, especially in the pyloric area, but not in that of the forestomach in mice.

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By means of quantitative immunochemical assay as well as activity determinations, depression of catalase in livers of mice injected with toxohormone was studied. The rate of reduction in the activity of liver catalase was found to be proportional to that in the actual concentration of the enzyme protein.
Depression of the activity of liver catalase by toxohormone was considered to be due to the decreased rate of synthesis of the enzyme protein, taking the result of our previous experiment into account.
Heterogeneity of chromatographic pattern of liver catalase of mouse in the course of purification of this enzyme is discussed, suggesting possible presence of isozymes of catalase in the mouse liver.

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1) Delayed hypersensitivity to tuberculin antigen was tested on 325 patients with advanced cancer, 442 patients with various non-cancerous diseases, 83 patients with pulmonary tuberculosis, and 356 subjects with no detectable diseases. Only 32.6% of the cancer group showed positive response in contrast to 65.5% of the non-cancer group, 92.8% of the tuberculosis group, and 69.1% of the non-diseased control group. The BCG vaccination hardly elicited a positive skin reaction in cancer patients in latent tuberculin allergy.
2) The humoral antibody response to the phosphatide fraction of tubercle bacilli was determined in 48 patients with advanced cancer, 33 patients with various non-cancerous diseases, and 35 patients with pulmonary tuberculosis. The humoral antibody was detected in half of the cancer group as well as in the majority of the non-cancer and tuberculosis groups. In most of the cancer patients who showed negative result, the response was elicited by BCG vaccination.
3) The results obtained in this study and available evidences indicate that the advancement of carcinoma is characterized by the dissociation in the way of response between the two types of immunological reactions; humoral response and cell-mediated one. This altered immune status was discussed in the light of the impaired function of immunologically competent cells.

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DNA content of individual nuclei in six different hypo- and hyper-diploid ascites hepatomas of the rat was measured by Feulgen-microspectrophotometry using ascites smears. Ascites hepatoma cells, even those with hypo-diploid chromosomes, had a larger amount of DNA, when compared with normal leucocytes.

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