Journal of oral pathology最新文献

The effect of long standing mechanical irritation of the tongue was studied in 100 young rats. This was effected by the protruding end of a twisted wire, ligated around the lower first molar and directed toward the later-ventral aspect of the tongue on one side, while the other side served as control. Groups of rats were killed after 3, 6, 9 and 12 months and the tongues were examined grossly and microscopically. Fibrous hyperplasia was observed in 48% of tongues in the 3-month group and increased to 79% in the 12-month group. Microscopically, epithelial changes were noted which included ulceration acanthosis and hyperkeratosis. In no instance was dyskeratosis or any other malignant change noted.

A case of a peripheral odontogenic fibroma which contained aggregates of large granular cells is reported. These granular cells are similar to those previously described in the granular cell myoblastoma, congenital epulis and the granular cell ameloblastic fibroma. Deep extensions of the basal layer of overlying gingival epithelium, in double-strand fashion, are frequently observed in peripheral odontogenic fibromas. These strands closely resemble those seen in the tumor itself. On this basis, and as similar basal cell prolongations are seen in otherjaw lesions, it is postulated that residual ectomesenchymal influence may be responsible for inducing the basal cell proliferations in a similar manner to that which occurs during early embryonic dental development. This, it is suggested, might possibly be the histogenesis of the odontogenic epithelial strands in the peripheral odontogenic fibroma.

The relation of the clinical picture of snuff dipper's lesions to the histopathological appearance was studied in 114 male dippers aged 20-88 years. Histological study revealed increased epithelial thickness, a vacuolated surface layer with wavelike, eosinophilic spikes directed toward the surface having a narrow, eosinophilic band as a demarcation toward the prickle cell layer, acanthosis, and a slight inflammatory reaction. Thirteen cases showed an increased number of eosinophilic granulocytes, and nine cases contained amorphous, weakly eosinophilic areas in the connective tissue papillae. No epithelial dysplasia was observed. Increased epithelial thicknees, especially the presence of a vacuolated surface layer, was the only histologic feature that could be correlated with the severity of clinical appearance of the lesions. Deeply located changes, like inflammation and amorphous areas, however, were not reflected in the clinical grading of the lesions.

Stimulation of cell mediated immunity has been reported to be effective in bringing about clinical regression of carcinomas. The purpose of this pilot study was to investigate the possibility of introducing cell mediated immunity into an experimental animal-chemical carcinogenesis system (dimethylbenzanthracene-hamster cheek pouch) to serve as a model for the study of immunotherapy of oral cancer in humans. Contact hypersensitivity to dinitrochlorobenzene (DNCB) was induced in 17 Syrian hamsters via the abdominal skin. After secondary application of the allergen to the cheek pouch, local gross and histologic characteristics indicative of delayed hypersensitivity were observed. Control animals that had received only a primary or a secondary challenge with DNCB essentially showed no change. This study demonstrates that the buccal pouch of the Syrian hamster is capable of manifesting contact hypersensitivity to DNCB.

Biopsies from normal and malignant human oral epithelium were studied electron histochemically using lanthanum nitrate for a selective demonstration of junctional complexes at the plasma membrane of adjacent cells. The heavy metal complex was found to settle irregularly, sometimes in intimate proximity to the epithelial cell, in areas corresponding to the glycocalyx, gap junctions, desmosomes and nonspecific contact areas. Tight junctions were rarely seen. The lack of these morphological adhesive areas, the desosomal detachment seen between cancer cells and the increased lanthanum-positive cell surface may be possible factors responsible for the dissociation of oral malignant cells.

Electron microscopic study of oral mucosa from a patient with Anderson-Fabry disease (glycosphingolipid lipidosis) revealed lamellar and membranous osmiophilic intracytoplasmic inclusions having a periodicity of 4.5 nanometers. These were observed chiefly in reticulo-endothelial cells as membrane bound and occasionally unbound bodies. They could also be observed within the cytoplasm of squamous epithelial cells, particularly of the stratum germinativum. Morphologic features in endothelial and epithelial cells are described.

Mast cells obtained from a canine mastocytoma were maintained in cell culture for a period of 11 weeks. Samples of these cells were harvested for electron microscopic examination after 9 weeks in vitro. Although the overall morphologic appearance was sufficient to allow their identification as mast cells, the tumor cells differed in several respects from descriptions of normal tissue mast cells. In contrast to normal tissue mast cells, the tumor cells exhibited peripheral accumulations of microfilaments, randomly dispersed microtubules, and small clusters of smooth endoplasmic reticulum. The tumor mast cells also presented three different granule types: spherical granules with an amorphous and electron dense matrix; irregularly shaped granules possessing a limiting external membrane and an internal matrix containing laminated and/or coiled structures; and granules containing loosely coiled, unorganized membrane structures similar in appearance to myelin whorls. The canine mastocytoma is an excellent source of mast cells as they can be obtained in large numbers without contamination by extraneous cell types and the cells can be maintained in vitro for extended periods of time.