Observations on Oral Tumors In Vitro. III. Morphologic Properties and Longevity of Nonviral Intranuclear Inclusions23

Abstract

Intranuclear inclusions were observed in noninfected tissue cultures of strain KB cells and fibroblastoid cells from a facial biopsy explant from a boy with cherubism. Inclusions with different forms and content are shown in the micrographs, and one pair of inclusions was followed for 16 days by time-lapse cinemicrography. Changes occurred in the inclusions of the cells, although these cells appeared to be unusual in no other way. The inclusions shown, although similar to one another in many respects, are believed to be of two types. One is derived from an invagination of the nuclear membrane, leading to envelopment of cytoplasmic components,the other results from an interaction of nucleoli with folds of nuclear membrane. The long persistence of either type within viable cells is evidence against a viral causation.