Twenty female mice of dd strain received subcutaneous injections of a total amount of 2.5mg of 4-nitroquinoline N-oxide in 10 divided dosis. In all 10 mice survived more than 225 days, multiple pulmonary tumors were induced. Most of the tumors were designated as cystadenomas, histologically. In two cases among them, well-established adenocarcinomas with metastases were found. The result indicates that 4-nitroquinoline N-oxide may have distant carcinogenic action from the site of the injection.

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P³² uptake into DNA and RNA of chicken thymus gland in vitro was investigated at different stages of tumorigenesis caused by chicken sarcoma virus (Chiba's strain).
(1) The specific activities for the different portions of tumor were compared. The solid portion and the rudimentary thymus gland were on a similar level and the jelly-like portion was lower.
(2) From the 3rd to 7th day after virus inoculation, the specific activity of RNA was depressed, and from the 8th day this value increased compared with that of control. Specific activity of DNA changed also accompanied that of RNA.
From the above findings it was concluded that specific activities of RNA and DNA express cell reproduction, and there was no expression of the activity of RNA and DNA fractions ocurred from the 3rd to 7th day after virus infection, but the reason of this decrease is at present not clarified.

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1) The Crabtree effect occurs independently of the concentration of glucose added and lasts so long as the glucose remains. Lactate or pyruvate added together with glucose can not remove the Crabtree effect, showing the dominancy of glucose.
2) When homologous ascitic fluid fortified after Warburg with bicarbonate was employed as suspension medium, the overall gas exchange of tumor cells shows a linear increase of positive or negative pressure according to the presence or absence of glucose, respectively. When glucose concentrations are low (3•10^-3M and 10^-3M), linearly increasing positive pressure turns abruptly to negative pressure at certain points of incubation period and follows a linear line of negative pressure parallel to that in endogenous metabolism. This turning point of pressure is reached the sooner, the lower is glucose concentration.
3) Krebs-Ringer bicarbonate solution can replace completely the fortified ascitic fluid in respect to overall gas exchange.
4) The pattern of the Crabtree effect is greatly modified by the presence of bicarbonate and CO₂ in gas phase, namely, a marked fall of respiration at the early phase of incubation is followed by a rise of respiration which proceeds beyond the endogenous level.
5) The R.Q. value of endogenous respiration is of the order of 0.7, showing that endogenous metabolites consist chiefly of fatty substances. By contrast, the addition of glucose at high concentrations does cause a marked rise in R.Q., giving always a value greater than unity.
6) Resting upon these facts, it has been discussed that the Crabtree effect is a half manifestation of an integrated process of oxidation and reduction which is peculair to tumor cells and to which the presence of bicarbonate is of primary importance.

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A histochemical study under the condition of experimental skin carcinogenesis induced by 20-methylcholanthrene on the back of the mouse was carried out.
1. In processes of malignant growth, acid phosphatase, nonspecific esterase, β-glucuronidase, β-glucosidase and β-galactosidase showed nearly the same localization as in normal skin.
2. Protein-bound sulfhydryl and disulfide groups also exhibited similar patterns to intact skin.
3. Alkaline phosphatase gradually increased its activity in the portion adjacent to the proliferating epithelium but was completely inactive in cancerous tissues.

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In order to investigate the affinity of polyploid cells to various organs of rats bearing tumors, a common strain of Yoshida sarcoma in which polyploid cells were contained at a low percentage was used. Polyploid tumor cells showed much stronger affinity to spleen, kidney and lung, while the diploid ones showed stronger affinity to thymus and lymphatic glands. It was suggested that the polyploid cells can penetrate easier to organs through the blood system, but diploid cells infiltrate predominatly to lymphatic, glands through the lymphatic system.

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1. Correlative histochemical and autoradiographical studies were done on the mouse skin after the painting with tritium-labeled 4-nitroquinoline N-oxide.
2. A definite correlation was observed between the histochemical localization of SH-group and autoradiographical localization of the carcinogenic substance in the epidermis, although it was proved on the other hand that the substance does not usually penetrate deep enough and often becomes trapped in the superficial layers rich in SH-content.
3. The intense incorporation was observed in the regenerating cells, especially in the nuclei. The average ratio of the grain numbers over nuclear vs. cytoplasmic areas was 3.6:1.

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The effect of toxohormone prepared from Rhodamine-B fibrosarcoma on liver IPCE was studied both in vitro and in vivo. The activity of this enzyme was not depressed in both cases. Furthermore it was not affected in the tumor-bearing animals. Injury of heme biosynthesis at the step of iron insertion into protoporphyrin in the tumor-bearing animals or in the animals injected with toxohormone is not due to the inhibition of IPCE but to other factor or factors.

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