The aim of this study was to show the effectiveness of combining calcium phosphate cement and gelatin powders to promote bone regeneration in the canine mandible. We mixed gelatin powders with calcium phosphate cement to create a macroporous composite. In four beagle dogs, two saddle-type bone defects were created on each side of the mandible, and calcium phosphate cement alone or calcium phosphate cement containing composite gelatin powders was implanted in each of the defects. After a healing period of six months, mandibles were removed for µCT and histological analyses. The µCT and histological analyses showed that at experimental sites at which calcium phosphate cement alone had been placed new bone had formed only around the periphery of the residual calcium phosphate cement and that there had been little or no ingrowth into the calcium phosphate cement. On the other hand, at experimental sites at which calcium phosphate cement containing composite gelatin powders had been placed, we observed regenerated new bone in the interior of the residual calcium phosphate cement as well as around its periphery. The amount of resorption of calcium phosphate cement and bone regeneration depended on the mixing ratio of gelatin powders to calcium phosphate cement. New bone replacement was significantly better in the sites treated with calcium phosphate cement containing composite gelatin powders than in those treated with calcium phosphate cement alone.
We examined Notch signaling molecules, Notch1 and Jagged1, in serial large cases of typical solid/multicystic ameloblastoma. In general, Notch positive staining products were frequently detected in the cytoplasms of the cells. In the same cells, Jagged positive staining were also frequently observed, while only occasionally positive in peripheral cells, especially in cuboidal cells. The results showed that these morphogenesis regulation factors are closely related to cytological differentiation in neoplastic cells of ameloblastoma. The Notch and Jagged positive-cell ratios were frequently positive, and the ratios were nearly the same between the varied histopathological, cytological patterns. However, the less-differentiated cells were fewer in number than that of well-differentiated cells.
Oral lichen planus (OLP) can undergo malignant transformation and become squamous cell carcinoma (SCC). Oral infection with human papillomavirus (HPV) is associated with a significant risk of developing oral cancer. Although HPV DNA is detected more often in OLP tissue than in normal oral mucosa, there is as yet no firm evidence that HPV is a causative factor of malignant transformation in OLP. The objective of the present investigation was to assess HPV-genotype distribution in OLPs of Japanese patients and additionally to clarify the relationship between malignant transformation in OLP and HPV infection using PCR, in situ hybridization, and immunohistochemistry. DNA of 200 formalin-fixed, paraffin-embedded biopsy and surgical specimens of OLP was extracted. HPV infection was first detected by PCR using consensus HPV primers. Positive PCR samples were then further analyzed by PCR using HPV type-specific primers (HPV-6, -11, -16, -18 and -33). Eighty-three samples (41.5 %) out of the total 200 OLP specimens analyzed were HPV positive. In the HPV type-specific PCR assay, the most frequent type of HPV was HPV-16 (25.5 %), which is a high-risk type of HPV that is associated with malignant disorders and is often detected in SCC. The highest HPV-16 positive rate was obtained for the erosive type of OLP (28.3 %). Positive staining for HPV DNA by in situ hybridization was observed in the nuclei of cells in all layers of the epithelium in all HPV PCR positive samples. Immunohistochemically, nuclei of cells in the upper layer of the epithelium in all HPV PCR positive samples stained positive for the anti-HPV antibody. These results indicated that HPV-16 was often present in OLP of Japanese patients, especially in the erosive type of OLP, and suggested that HPV infection is a risk factor for malignant transformation in OLP lesions.
We have been conducting a survey on the birth prevalence of orofacial clefts, including cleft lip with or without cleft palate and cleft palate, in the Tokai area in central Japan every year for 37 years. Along with the yearly trends in the birth prevalence of orofacial clefts in that area for the past 37 years, we discuss whether the artificial abortion rate of fetuses with orofacial clefts has increased through the improved performance of ultrasonic imaging equipment. We also compare the yearly trends in the birth prevalence of congenital anomalies, including orofacial clefts, in Japan with those in other countries or areas where artificial abortion due to birth defects is legally permitted, and discuss the impact of improved accuracy of ultrasound imaging on the rate of artificial termination of pregnancy. The fact that the birth prevalence of orofacial clefts has basically remained unchanged for more than 30 years, even with recent more detailed prenatal diagnosis based on the improvement of ultrasonic diagnostic equipment, has allowed us tentatively to conclude that prenatal diagnosis is not currently threatening the right to life of the fetuses with orofacial clefts.
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