Abstract
An autoradiographic analysis of cellular proliferation in normal mucous membrane and tumor tissue of the mal regions of man in vitro: Under relatively simple methods with short-time incubation, we have studied living normal epithelial and tumor tissues in oral regions in vitro with the application of 3H-thymidine autoradiographically, in order to explain the relation between the histological findings and the mechanism of the cell proliferation, which were staying in the process of DNA-synthesis. As the material for the research, 12 tissue pieces were excised from the normal oral epithelium, 12 tissue pieces from the cancer, 4 from the ameloblastoma and 2 pieces from the others in the oral regions. By all these 12 materials of the normal epithelial tissues, the epithelial cells were labeled with silver grains autoradiographically, which lay till 3 or 4 epithelial layers above the basal cell layer. Their labeling index was 11.1% (with 95% confidence limit, 9.6-12.6%), with the mean value of all cases. Under 12 surgical or biopsy specimens of the cancer, the labeled cells were found in the 10 cases of autoradiograms. The group of the cancer showed a considerable variation of their labeling index from 10.0% (7.8-12.2%) till 32.2% (28.7-35.7%). Under the autoradiograms of 2 cases of the cancer not any labeled cell was found. With each 3 excised materials from the normal epithelial tissues and the cancers, the distribution of the labeled cells was examined respectively. By the group of the normal epithelial tissues, the labeled epithelium was found mainly in the stratum germinativum exclusively and in all basal cell layers, and located regularly but dispersedly. On the contrary, the distribution of the labeled cells of the cancers was observed in an irregular arrangement and found in several limited parts of the specimens intensively and densely in groups.
