We report a rare case of intravascular papillary endothelial hyperplasia (IPEH) arising from the upper lip. Pathologically, it consisted of a few lobulated masses lined by an incomplete fibrous capsule of variable thickness which was separated from the surrounding tissue and which partially formed papillary structures bearing fibrous stalks and a single layer of endothelium. The capillary formation was poorly defined, and mitotic figures were frequently observed. Immunohistochemically, the endothelial cells were positive for factor VIII related antigen and vimentin, and many cells were positive for PCNA, not only in the solid proliferating area but also in the papillary proliferating area. This case represents IPEH with high proliferative activity.

These results suggest that neither EMD nor PGA has the ability to induce hard tissue and that EMPs contained within EMD might aggregate on the dentin surface and inhibit the effect of the demineralized dentin matrix.

Fig. 1 A schematic diagram of the cell loading procedure. Cultured cells were loaded by a transparent glass plate, which is 2.5 2.5 0.5 cm, weighing approximately 9.0 g.

The purpose of the current study was to evaluate the bone formation when β-tricalcium phosphate (TCP) was implanted in bone defects of rat femurs. β-TCP granules were applied to defects created in the femurs of 65 male rats who were sacrifi ced 3, 7, 10, 14 or 30 days later. Bone tissues were embedded in paraffi n, serial sections were cut and then stained with hematoxylin-eosin. Histomorphometric analyses were also conducted. Furthermore, total mRNAs were extracted, homogenized, and reverse transcribed, after which quantitative PCR assays were conducted with a LightCycler™ using the double-stranded DNA dye Syber Green I with primers for either rat osteopontin or osteocalcin. Tissues in defects without β-TCP were used as controls. The amount of newly formed bone tissue in the β-TCP implanted group was signifi cantly greater in both the side areas and the central area of defects than in the control group. Expressions of osteopontin and osteocalcin mRNAs of cells in the defects of the experimental group were up-regulated compared with the control group at all time periods. Taken together, these results prove that β-TCP is an appropriate material for osteoconduction and promotes bone formation in bone defects.

The purpose of this study was to investigate a case of calcifying odontogenic cyst (COC) in which numerous calcifications were observed not only in the lining epithelium, but also in the cyst wall, using cytokeratins 13 (CK13), 19 (CK19), and core binding factor a-1 (cbfa-1) as primary antibodies. Cells of Malassez's epithelial rest were stained as controls.Cells of the epithelial nests in the cyst wall were reactive for CK13, but their CK19 staining was similar to that observed in the lining epithelial cells. Calcifying nodules were reactive only for CK13. Cells of Malassez's epithelial rest were reactive for CK19 but not for CK13. Cbfa-1 positive reactivity was observed only in nuclei of spindle cells in the periodontal ligament. CK13 was positive superficial to the prickle cells. CK19 was positive in the basal cells of the oral mucosa. In the lining epithelium of the cyst, the expressions of CK13 and CK19 were similar to their immunoreactions in the oral mucosa. These results suggest that the odontogenic epithelium differentiated into squamous epithelial cells, which began as ghost cells in the COC, and that this process depended on the dystrophic calcification of differentiated odontogenic epithelial cells, not of osteogenic cells.