Acta Medica Okayama 20巻 4号

With the purpose to prevent the dissemination and consequent metastasis of cancer cells at the time of operation we gave 10 mg of Mitomycin C per day for four consecutive days prior to surgical operation of gastric cancer (total of 322 patients), and this so-called adjuvant chemotherapy proved to be effective on the cases with serosal involvement and infiltrating type of cancer, irrespective of histological types. It also gave five-year survival rate of 35 per cent. However, to lymph nodes already metastasized, the adjuvant chemotherapy proved to be not effective.

Large doses of adenovirus type 12 were injected intraperitoneally into adult hamsters, and development of tumors and other pathological findings were studied in comparison with those in hamsters injected when newborn. Doses of 38~47 TCID60 per gram body weight produced tumors in 3 of 12 hamsters injected at 37~57 days of age. A dose of 170 TCID60 per gram body weight produced tumors in one of 18 hamsters injected at 61~71 days of age, but in none of 18 hamsters injected at 147~174 days of age, while the same dose per gram body weight produced tumors in 24 of 26 hamsters injected when newborn. In hamsters injected at adult ages, the number of tumors per animal decreased and the latent period for tumor development became very long as compared with those in hamsters injected when newborn. Regardless of the age at the time of injection, acute inflammatory change was observed in the peritoneum which later developed into various degrees of peritoneal adhesion. Adenovirus type 3 also induced the peritoneal adhesion. Histology of tumors was studied and discussed.

DNA synthesis and cell renewal of mouse intestinal epithelium were studied with radioautography after injection of thymidine-H³ to know the difference of the mode of epithelial cell generation relating to the different frequency of cancer developement in several parts of small and large intestines. Succinic dehydrogensase activity was also observed by histochemical method. Renewal time of the intestinal epithelium of mouse is about three days throughout the intestine with somewhat longer time in rectum and anus, and relatively shorter one in ileum compared to the other parts of the intestine. Daily regenerating rate was low in large intestine, especially in rectum and anus. Strong activity of succinic dehydrogenase appeared in the bottom of crypt and seems to be correlated to the active cell division. Epithelial cells in large intestine move very slowly upward and few of them seem to move to the opposite side or stay long time at one place. Intermitotic time is about 27 hours in small intestine and about 40 hours in large intestine. These suggest some relations between the mode of the epthelial cell renewal and cancer development. Because in human the frequency of cancer development is very high in large intestine, rectum and anus, and the epithelial renewal of these areas is supposed to be delayed similarly as in mice.

Histochemical evaluations of human sarcomas such as reticulum cell sarcoma, fibrosarcoma, lymphosarcoma and neurofibrosarcoma, were carried out with five hydrolytic enzymes and eight oxidative enzymes. The activities of acid phosphatase and beta-glucuronidase were slightly positive in the neoplastic cells observed. Beta-esterase activity was also positive but varied according to the kind of sarcomas. Alkaline phosphatase activity was faint or negative in sarcoma cells, though positive in capillary walls. Leucine aminopeptidase activity was negative giving not any appreciable coloration of the cell as far as the method employed is concerned. Among the activities of dehydrogenases, the most intense activity was observed in lactic dehydrogenase. The activities of succinic and beta-hydroxybutyric dehydrogenases were slight. The activities of alpha-glycerophosphate, glutamic and betahydroxybutyric dehydrogenases were faint or slight. The activities of NADPlinked dehydrogenases, glucose-6-phosphate and isocitric dehydrogenase were all faint or slight in these sarcoma cells.

Detailed morphologic characteristics of type C virus particles observed in an X-ray-induced C58 mammary tumor and its transplants have been described. The particles are round and 75 to 100 mμ in diameter, containing an electrondense nucleoid 60 to 70 mμ in diameter. By the negative staining, they do not show obvious spines. Two abnormal types of particles, i. e. cylindrical and aberrant forms have been observed.