No abstract

No abstract

The present study investigated how cell plating density and extracellular matrix protein influence cell survival of epithelial rests of Malassez (ERM) in vitro. ERM cells were plated on culture dishes coated with laminin (LM), type IV collagen (type IV), or fibronectin (FN), or on noncoated dishes, (Non) at a cell density of 2 x 104-1 x 105/ml in a nonserum culture medium. XTT assays were performed to calculate the number of cells attached on the substrata after 6, 24, 48, and 72 h. Mean cell numbers were calculated, and significant differences were determined using ANOVA. When epithelial cells were cultured on various matrices at a cell density of less than 2 x 104/ml, the cells did not grow and then fell into apoptotic cell death, which was confirmed by transmission electron microscopy. The cell number was significantly increased in cells plated on FN compared to those on Non at a cell density of 4 x 104/ml-8 x 104/ml. These results suggest that both extracellular matrix proteins and cell-cell interactions may contribute to prevent apoptosis of ERM in vitro. Cell-cell interactions may be a more important factor than exogenous extracellular matrix proteins for the survival of ERM cells in vitro.

No abstract

The present study investigated the localization of biglycan, decorin and large chondroitin-sulphate proteoglycans (versican) in 32 cases of pleomorphic adenoma (PA) by immunohistochemical staining. The neoplastic epithelium of PA showed wide staining for versican and biglycan. Myxomatous and chondroid tissues showed restricted staining for versican and biglycan. The intense staining for decorin was observed in fibrous connective tissue of the capsule, whereas only one case in the present study showed the positive staining for decorin in the mesenchymal tissues of PA. These results indicated that both biglycan and versican might be involved in, at least in part, the morphogenesis of neoplastic epithelium and mesenchymal tissues in PA.