Hirotsugu Izumi

Nodular fasciitis of the upper labial fascia: Cytometric and ultrastructural studies

The rare case of nodular fasciitis in the upper labial fascia is reported. Light microscopic, electron microscopic and cytometric studies were performed. The histopathology corresponded to intermediate and reactive types in the Price and Bernstein classification. Cytometric study of evaluating DNA of fibroblasts revealed a high distinct peak in myxoid and inflammatory areas. Ultrastructurally, fibroblasts and myofibroblasts were identified in the lesion. Reported Japanese cases of orofacial nodular fasciitis are reviewed and compared with the European-American literature.

Stimulation of plasmin activity in cultured human fibroblast cells by Porphyromonas endodontalis

1. Plasmin activity in the conditioned medium of Gin-1 cells, a human gingival fibroblast cell line, was stimulated by Porphyromonas endodontalis, a putative pathogen of oral submucous abscesses, in a time- and dose-dependent manner. 2. P. endodontalis stimulated the activity of plasminogen activator in both the conditioned medium and the cell lysate. The plasminogen activator in Gin-1 cells was approx. 50 kDa by zymography. 3. The conditioned medium of Gin-1 cells exposed to P. endodontalis stimulated the conversion of human serum prekallikrein to kallikrein. 4. These results suggested that P. endodontalis stimulates the plasminogen activator-plasmin system in Gin-1 cells, and that activated plasmin plays a role in the progress of periodontal tissue inflammation.

Suppurative osteomyelitis of the mandible in a child

The rare case of osteomyelitis of the mandible in a 4-year-old boy is reported. The literature of osteomyelitis in children is reviewed and discussed. Osteomyelitis in children is mainly affected in the mandible. In childhood, mandibular structure is so immature that the inflammation of the mandible extends easily and rapidly to a wide area. It is very difficult to perform adequate treatment. The therapy for osteomyelitis in childhood must be carried out after due consideration of the stage and anatomical features.

Platelet-activating factor stimulates production of prostaglandin E2 in murine osteoblast-like cell line MC3T3-E1

We found that platelet-activating factor (PAF) stimulated the production of prostaglandin (PG) E2 in MC3T3-E1 cells in a time- and dose-dependent manner. 1.0 microM PAF gave a maximal stimulation of PGE2 production by MC3T3-E1 cells after a 4 hr PAF-treatment. Furthermore, the PAF-induced PGE2 production was abolished by the pre-treatment of the cells with a PAF receptor antagonist, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phospho(N,N,N-trimethyl)hexanolamine, which occupied the same receptor site as PAF. These results suggest that PAF stimulates the PGE2 synthesis through a PAF receptor mediated pathway. Possibly PAF modulates bone metabolism by stimulating PGE2 synthesis.