The α-defensins are a group of antimicrobial peptides which have a potent antifungal activity against Candida species. The present study was conducted to investigate the expression and significance of human α -defensins/human neutrophil peptides 1-3 (HNP 1-3) in chronic hyperplastic candidiasis (CHC) with regard to the degree and distribution of fungal invasion. Immunohistochemistry was conducted to compare CHC samples (n=16) with samples of Candida negative leukoplakia without definite epithelial dysplasia (LP) (n=9). The type of fungal invasion (localized, uniform, or no invasion) was compared with regard to HNP 1-3 immunoreactivity. The patterns of HNP staining were localized or diffuse in the epithelium of CHC and negative in LP. Histological types of invasion were significantly correlated with the HNP positivity (P<0.01). Many neutrophils in the epithelia of CHC were found to be positive for HNP.
These findings suggest that neutrophils aggregate and form microabscesses in CHC depending on the type of candidal invasion, subsequently releasing HNP 1-3 towards the infective foci to control further invasion.

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The expression pattern of cytokeratins (CKs) varies with epithelial cell type. However, the expression of many different CKs has not been clearly defined in ameloblastomas. We used cytokeratins (CK) 1, 4, 6, 7, 10, 10/13, 15, 16, 17, 19, 20 and AE1/AE3 monoclonal antibodies and polyclonal keratin (PK) antibody to elucidate the localization of these CKs in ameloblastomas by immunohistochemistry. Biopsy and operative specimens of 31 ameloblastomas, of which 13 were follicular and 18 plexiform, were used in the present study. CK8, CK19, AE1/AE3 and PK were positive in all follicular (100%) and plexiform (100%) patterns of ameloblastomas. Although CK8 and CK19 are present in simple epithelium, they were observed in the inner cells of tumor nests of ameloblastomas. CK13 was also positive in all metaplastic epithelium of follicular patterns (100%) and was positive in plexiform patterns (56%). CK6, CK7, CK15, CK16 and CK17 positive rates were 54%, 8%, 23%, 46% and 54% in follicular patterns, and 22%, 17%, 0%, 0% and 11% in plexiform patterns, respectively. CK1, 4, 10 and 20 were negative in all both follicular and plexiform patterns. These results indicate that CK15 and CK16 tend to be more specific positive in follicular than in plexiform ameloblastomas.

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In the present study, the effects of both growth factor TGF- α and carcinogen Trp-P-2 on the development of organ-cultured ddY mouse tooth-germ which was transplanted into the subcutaneous tissue of nude mice were investigated histologically, immnohistochemically (PCNA) and histometrically in 5 groups of mice, namely Group A (Control), Group B (DMSO), Group C (TGF-α), Group D (Trp-P-2) and Group E (TGF-α + Trp-P-2). Histologically, in Groups C, D and E, marked proliferation of odontogenic epithelial cells was observed. In Groups D and E, keratinization of the odontogenic epithelial cells was found, but it was not observed in Group C. Moreover, in Group E, a cyst-like space was observed in the area of odontogenic epithelial cells. Immunohistochemically, in Groups C, D and E, PCNA-positivities of the odontogenic epithelial cells were significantly higher than those of Group A. Histometrically, in Groups C and E, the size of the tooth germ was significantly larger than that of Group A. The results of the present study suggest that proliferation, keratinization, cyst-like space formation of odontogenic epitherial cells of transplanted organ-cultured tooth germs in mice were promoted by growth factor TGF- α and carcinogen Trp-P-2.

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Primary intraosseous squamous cell carcinoma was reported in a 76-year-old Japanese woman. The patient exhibited bone expansion of the premolar-molar region of the left mandible with unilocular radiolucency surrounded by indistinct margins. Biopsy revealed a cystic cavity lined by non-carcinomatous squamous epithelium focally exhibiting epithelial dysplasia and distinct basal cell palisading. However, the overlying oral mucosa was normal in appearance. Under the provisional diagnosis of carcinoma arising in odontogenic cyst, segmental resection of the mandible and supraomohyoid neck dissection was performed. The resected mandible had a unicystic lumen lined by papillary or verrucous proliferation characteristic of welldifferentiated squamous cell carcinoma. However, invasion of the malignant cells along the displaced inferior alveolar nerve was not seen. There was no trace of unicystic ameloblastoma. No lymph node metastasis was confirmed. From these clinical, radiographic and histological findings, the present carcinoma was strongly suspected to be derived from a pre-existing keratocystic odontogenic tumor.

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