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The distribution pattern of certain monosaccharides in the epithelial cells of the hamster buccal pouch was studied during carcinoma development induced by 9,10-dimethyl-1,2-benzathrancene (DMBA). An avidin-biotin-peroxidase complex (ABC) immunohistochemical technique with high affinity biotinylated lectins was employed to identify monosaccharides. Lectins used in this experiment included Concanavalin A (Con A), for identifying mannose or glucose, Ricinus communis agglutinin I(RCA-I), for identifying galactose, and Ulex europaeus agglutinin I(UEA-I), for identifying fucose. The results show that in normal buccal pouch epithelial cells, fuctose or galactose were concentrated predominantly on the cellular membrane, while mannose and glucose were distributed in the cytoplasm. In the epithelial cells undergoing neoplastic transformation induced by DMBA, most cells showed decreased staining of the above-mentioned monosaccharides, while in other areas the cells were heavily stained. However, the most striking change which occurred was that galactose and fucose shifted from the cellular membrane to the intracytoplasmic area during the malignant transformation. Thus, the changes of anatomic location and intensity of staining of monosaccharides in the buccal pouch epithelium may be used as a criteria for early histochemical diagnosis of malignant transformation. [ABSTRACT FROM AUTHOR]

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S phase of the cell cycle which can be detected immunohistochemically in paraffin-embedded tissue as a useful marker for the proliferating fraction of cells in tissue specimens. Thirty-eight cases of oral squamous cell carcinoma were studied in groups according to clinical staging and histological grading (UICC system), these included 5 cases of T1, 13 cases of T2, and 20 cases of T3, and 19 cases of Gl, 12 cases of G2, and 7 cases of G3. The mean percentage of PCNA positively stained tumor cells in this series was 29.2. The mean percentages of PCNA-positive cells in each stage and grade were: T1 (13.7%), T2 (24.4%), and T3 (34.3%); GI (30.5%), G2 (24.8%), and G3 (33.2%). The results indicate that the percentage of PCNA positively stained tumor cells in oral squamous cell carcinoma was significantly greater when tumor size was larger than 2 cm (T1 versus T2/T3). However, there was no significant difference between T2 and T3. There was no correlation between the number of PCNA- stained tumor cells and histological grade. [ABSTRACT FROM AUTHOR]