ABSTRACT
BACKGROUND: Primary stability is an important prognostic factor for dental implant therapy. In the present study, we evaluate the relationship between implant stability evaluation findings by the use of an implant stability quotient (ISQ), an index for primary stability, and a morphological evaluation of bone by preoperative computed tomography (CT). SUBJECTS AND METHODS: We analyzed 98 patients who underwent implant placement surgery in this retrospective study. For all 247 implants, the correlations of the ISQ value with cortical bone thickness, cortical bone CT value, cancellous bone CT value, insertion torque value, implant diameter, and implant length were examined. RESULTS: 1. Factors affecting ISQ values in all cases: It was revealed that there were significant associations between the cortical bone thickness and cancellous bone CT values with ISQ by multiple regression analysis. 2. It was revealed that there was a significant correlation between cortical bone thickness and cancellous bone CT values with ISQ by multiple regression analysis in the upper jaw. 3. It was indicated that there was a significant association between cortical bone thickness and implant diameter with ISQ by multiple regression analysis in the lower jaw. CONCLUSION: We concluded that analysis of the correlation of the ISQ value with cortical bone thickness and values obtained in preoperative CT imaging were useful preoperative evaluations for obtaining implant stability.
ABSTRACT
We previously found that CD44high/ESAlow head and neck squamous cell carcinoma (HNSCC) cells harboring high dihydropyrimidine dehydrogenase (DPD) expression exhibited potent resistance to 5-fluorouracil (5-FU)-induced apoptosis. In addition, susceptibility of HNSCC cells to 5-FU was compromised in the presence of cyclooxygenase 2 (COX2)-derived prostaglandin E2 (PGE2). In this study, we examined 5-FU-induced apoptosis in sorted cell populations (i.e., CD44high/ESAlow, CD44high/ESAhigh, and CD44low cells from the HNSCC cell line A-253) to clarify the anti-apoptotic effect of PGE2 on CD44high cells. Notably, CD44high/ESAlow cells upregulated PGE2, compared with other populations. To investigate the effect of CD44high/ESAlow cell-derived PGE2 on CD44high/ESAhigh cells, direct and indirect co-culture assays were performed. The percentage of apoptotic cells in a culture of CD44high/ESAhigh cells was significantly reduced when they were directly and indirectly co-cultured with CD44high/ESAlow cells. Furthermore, 5-FU-induced apoptosis of CD44high/ESAhigh cells was significantly increased in the presence of an inhibitor of the PGE2 receptors (EP1/EP2) when CD44high/ESAhigh cells were co-cultured with CD44high/ESAlow cells. These results suggest that CD44high/ESAlow cell-derived PGE2 may contribute to the inhibition of 5-FU-induced apoptosis in CD44high/ESAhigh cells. Additionally, NR4A2 knockdown enhances 5-FU-induced apoptosis in CD44high/ESAhigh cells, suggesting that PGE2 attenuates 5-FU-induced apoptosis in an NR4A2-dependent manner in CD44high/ESAhigh cells. In conclusion, CD44high/ESAlow cells contribute to induction of resistance to 5-FU in CD44high/ESAhigh cells through provision of PGE2. CD44high/ESAlow cell-targeted therapy may be effective in treatment of HNSCC.
ABSTRACT
We examined 66 oral squamous cell carcinomas (OSCCs) for human papillomavirus-16 (HPV-16) infection to evaluate its prognostic significance. Cox regression analysis of 5-year survival demonstrated that patients without nodal metastasis or with intratumoural HPV-16 showed better prognoses compared with each counterpart. In Kaplan-Meier survival analysis, nodal status but not HPV-16 status was statistically significant. The 5-year survival rate of HPV-16 positive patients without nodal metastasis (94%) was extremely high, compared with that of HPV-16 negative patients with nodal metastasis (25%). These results suggest that HPV-16 status as well as nodal status may provide prognostic significance in patients with OSCC.
