Observations on Oral Tumors in Vitro

1. Zeiosis versus the Nucleus and Endoplasmic Reticulum in Strain KB

¹ Department of Medicine, University of Texas Dental Branch, Houston, Texas, Department of Biology, University of Texas M. D. Anderson Hospital and Tumor Institute, Houston, Texas, Pasadena Foundation for Medical Research, Pasadena, California

Cells from the oral carcinoma strain KB were cultivated in multipurpose culture chambers under strips of dialysis cellophane. In certain areas these cultured cells were observed to undergo a blebbing activity at their periphery, termed by Costero and Pomerat as "zeiosis" ("to boil over"). The general occurrence of this phenomenon in some cells cultivated in these conditions, as well as that of cells in additional experimental conditions reported by others, was discussed. A time-lapse motion-picture series was shown to denote the reversibility of the zeiotic phenomenon in this environmental condition. Two cells that had zeiotic protrusions, one containing a nucleus and other elements of the cytomembrane system, were shown in time-lapse sequences. Of particular interest was the constriction ring activity in some of the zeiotic extensions.