Liver-cell Nuclei during the Development of Hepatoma Produced by Butter-Yellow

Abstract

Cell nuclei of YOSHIDA's ascites sarcoma were studied by MAKINO and many others. But karyological studies on hepatoma produced by butter yellow were undertaken by AMANO (1940) and TYUMA (1948). Concerning nucleus morphology during tumor development is, however, still much unknown.After a month administration of butter yellow, abnormalities in nuclear division took place, and they were demonstrable at the end of 4th to 7th month. The abnormal figures are heteroploidy of chromosomes, ir-arrangement on the equatorial plate, chromosomal confusion, spherization of chromosomes, bridge formation of chromosomes, non-disjunction of chromosmes, multipolar division and amitosis, which take place before the formation of the tumor. The ratio of number of abnormal mitosis to the normal one is lower than 1 from the beginning to the end of 3rd month, then after the 4th month it rises over 1 till the time of tumor formation, so that the precarcinoma period can be divided into 2 stages. These facts suggest to us that the ratio can be a sign of precarcinoma period. In the abnormal divisions induced by butter yellow no such peculiar karyoutypes were seen in all stages of the precarcinoma, as were found in many kinds of ascites sarcoma cells.