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Get PDFThe aim of this study was to analyze the vibratory characteristics in the maxillary dentition of 4 cleft lip and palate (CLP) patients before and after bone grafting. First, the central incisor on the noncleft side was impacted with an impact hammer, and the responses were received using an acceleration sensor from the teeth between the upper first molars on both sides. The transfer functions were then obtained from each measurement point using a fast Fourier transform analyzer. Finally, a computer analysis and simulation were performed based on the measured transfer functions to obtain the natural frequency, modal shape, decay rate (DR) and maximum displacement (MDP). Before bone grafting, distinct phase differences between the major and minor dental arches (MDA and mDA) were observed in the modal shapes. After surgery, however, both the MDA and mDA vibrated in phase. These results were identical in all subjects. The MDPs of the central incisors conspicuously decreased after bone grafting in 3 subjects. From the standpoint of vibratory characteristics, this study indicated that bone grafting had a favorable effect on prosthodontic treatment using a fixed prosthesis across the cleft in CLP patients.departmental bulletin pape
Get PDFThe elevation of non-specific IgE (total IgE) in Ascaris infection can be seen one week after infection, and reaches a peak after approximately two weeks. It has been reported that ABA-1 protein is the main constituent in the pseudocoelomic fluid of Ascaris suum. To investigate the effect of the ABA-1-like protein from Ascaris lumbricoides (ALB), the cDNA was cloned by reverse transcriptase polymerase chain reaction, using original primers based on the consensus sequences of ABA-1 and TBA-1, that is an ABA-1-like protein from Toxocara canis. The clone was sequenced, we constructed the recombinant polyprotein of ALB (rALB14 and rALB7) based on the ALB sequence, and rALB was administrated to BALB/c mice. Fourteen days after inoculation with rALB 14 which is the full length of ALB, the elevation of total IgE which we supposed to contain non-specific IgE was observed, and the results were as we expected. Furthermore, in an in-vitro experiment, we confirmed that the spleen cells proliferated when stimulated by rALB14 and concanavalin A. Therefore, the whole conformation of ALB is considered to be involved in the elevation of non-specific IgE, and is involved in the activation of T cells.departmental bulletin pape
Get PDFPurpose: The purpose of this study was to investigate the dynamic retentive force of a mandibular unilateral distal-extension partial denture framework with a back-action clasp that was designed in a buccally tilted cast on a dental surveyor. The retention mechanism of this framework was analyzed in comparison with other typical unilateral and bilateral frameworks for the mandibular Kennedy class II case. Materials and Methods: Experimental gold alloy frameworks of three designs were repositioned to the master cast, and lifted upward to the vertical direction to the occlusal plane. The load required to dislodge each framework was recorded. The retentive force of each framework was determined by the maximum load in a dislodgment cycle. The bending strength of a plain clasp pattern of the same length as the clasp arm used in each framework was also measured by cantilever beam test. Results: The mean retentive force of the unilateral framework with a back-action clasp of relalively low bending strength was significantly higher (P < 0.01) than that of the unilateral framework with two Akers clasps of relatively high bending strength, and 70 to 80% of the bilateral framework with two Akers clasps on the edentulous side and a double Akers clasp on the contralateral side. The unilateral framework with a back-action clasp showed the greatest early load resistance in the dislodgment cycle among the three designs. Conclusion: The reasonable retention mechanism was demonstrated by the unilateral framework with a back-action clasp.departmental bulletin pape
Get PDFOral cancers of tobacco and betel chewers represents a unique in-vivo model to understand the genotoxic effect of tobacco and betel carcinogens on oncogenes and tumor suppressor genes. Coordinated interactions of p53 and MDM2 play an important role in regulation of critical growth control gene following exposure to DNA damaging agents. The purpose of this study is to determine if the tumor suppressor function of p53 is inactivated by mutation or other alternative mechanisms in carcinogen-induced oral squamous cell carcinoma (SCC), and to investigate the clinicopathological significance of p53 and MDM2 expression. The p53 mutation in oral SCC of tobacco and betel chewers (n=40) was detected by polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP) analysis and immunohistochemistry (IHC) was done to investigate p53 and MDM2 proteins overexpression. The incidence of p53 mutation was relatively low (17.5%), but there was a high prevalence of MDM2 overexpression (72.5%). In the total of 40 cases, IHC phenotype showed p53 positive immunostaining with MDM2 positive immunostaining (p53+/MDM2+) 62.5%, p53 negative immunostaining with MDM2 negative immunostaining (p53-/MDM2-) 15%, p53 positive immunostaining with MDM2 negative immunostaining (p53+/MDM2-) 12.5%, and p53 negative immunostaining with MDM2 positive immunostaining (p53-/MDM2+) 10%. A significant correlation was found between MDM2 and p53 overexpression (p=0.0289). Moreover, p53+/MDM2+ phenotype was significantly associated with poorly differentiated tumors (p=0.0007). These results conclude that other factors than p53 mutation is likely to be the targets of tobacco/betel carcinogens and MDM2 may play an important role in tobacco/betel chewing-related oral SCCs. Overexpression of MDM2 protein may constitute an alternative mechanism for p53 inactivation.departmental bulletin pape
Get PDFIn this research we developed an orthodontic simulator for analysis of orthodontic forces distribution in the case of the continuous arch technique. In order to take into account vertical force, besides horizontal force and occlusogingival moment on instrumented artificial tooth, tooth root was designed as a ring load cell. Fixing each artificial tooth onto combined mechanical stages enabled variation of tooth anteroposterior position and inclination related to occlusal plane. Calibration of forces and moment of each instrumented artificial tooth showed linearity of outputs and provided the generalized inverse matrix for evaluation of forces and moments from measured strain data.A simulation to retract the anterior teeth was accomplished, and distribution of forces and moment acting at the bracket of each tooth were determined. The average accuracy was 82% and 97% in the horizontal and vertical direction, respectively, by comparing the applied forces and the evaluated ones.departmental bulletin pape
Get PDFWiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by thrombocytopenia, eczema and immunodeficiency. WASP, the gene responsible for WAS, has been identified by positional cloning, contains a PH domain, a GBD domain, a proline rich region, and a verprolin/cofilin homology domain. Subsequent studies suggest that WASP is involved in signal transduction and in the regulation of the cytoskeleton.departmental bulletin pape
Get PDFWe investigated the significance of a pool of mucin, individually termed mucinous component (MUC), at the leading invasion edge of colorectal submucosal invasive carcinoma (SIC). In particular, we studied the correlation between pathological adverse prognostic factors and stainability of the mucosubstances and tumor-associated glycoconjugates in MUC. We demonstrated that MUCs were present in 21% of SICs, and 20% of SICs with MUC were involved in metastasis or recurrence, while only 6% of SICs without MUC were positive for it (p=0.005). SICs with MUC showed strong staining of carcinoembryonic antigen and Ulex europaeus I in the MUCs as well as in the cancer cells with high-grade atypia. Moreover, the mucins in MUCs predominantly stained for sialomucin. This study was the first to investigate the importance of mucous nodules in colorectal SIC. We concluded that MUC in SIC would be an important adverse prognostic factor, and that we should at least consider employing a similar treatment strategy for it to advanced colorectal carcinoma.departmental bulletin pape
Get PDFWe investigated the effect of endogenous bradykinin on adrenaline-induced pulmonary edema (PE) by blocking bradykinin receptors. In preliminary experiments, a bolus injection of adrenaline (ADR; 10 μg/kg) solution (10 μg/ml) was determined to be an edematogenic dose for inducing PE. The lung body weight index (LBI) and incidence of PE (IPE) were determined. The IPE and LBI of the group pretreated with Des-Arg9-[Leu8]-Bradykinin (DA-BK, 50 μg/kg, 50 μg/ml) increased significantly compared with those of the control group (p<0.05). On the other hand, there were no remarkable changes in IPE and LBI in the groups pretreated with Hoe140 (D-Arginyl-[Hyp3, Thi5, D-Tic7, Oic8]-Bradykinin (100 μg/kg, 100 μg/ml), captopril (20 mg/kg, 20 mg/ml) or L-NAME (1 mg/kg 1 mg/ml). Moreover, the IPE and LBI of the group co-treated with L-NAME and DA-BK decreased compared with the DA-BK group (p<0.05). Thus, bradykinin aggravates adrenaline-induced PE through activation of the B2 receptor by the kallikreins as a result of the ADR administration, although the precise mechanism is not known.departmental bulletin pape
Get PDFThe long period of external fixation after the completion of distraction, which is necessary to obtain enough strength for resisting without fixation is a significant disadvantage of distraction osteogenesis. The purpose of this study is to understand the mechanical property of the regenerated bone and try to find an appropriate timing for safely removing the fixation device. An external fixation device was applied to the right tibia in rabbits and transverse osteotomy was performed just below the tibio-fibula junction. The tibiae were lengthened 7.2 mm at 0.72 mm a day for 10 days after surgery. A bone mineral density (BMD) and stress strain index (SSI) analyzed by peripheral quantitative computed tomography showed a significant increase on day 40, but returned to the control level at day 64 after the completion of distraction. Therefore, the newly formed bone between the host cortical bone seemed to be enouth to resist the mechanical stress on day 40 during the consolidation period in this study. The present results suggested the possibility of removing the fixation device during the period when the BMD and SSI showed a significantly high level during the consolidation period.departmental bulletin pape
Get PDFIn order to understand the pathogenesis of gastric lymphoma, we investigated the association of H.pylori infection with lymphoid follicular hyperplasia. Eighty-four gastric specimens removed for gastroduodenal ulcer were histologically examined. The distribution and prevalence of H.pylori, neutrophilic and lymphocytic infiltration, mucosal atrophy, intestinal metaplasia, and lymphoid follicles were scored. The lymphoid follicles were more frequently observed in H.pylori positive cases. They indicated a positive correlation with the score of H.pylori. When follicular gastritis (FG) was defined as a case in which the secondary lymphoid follicles (Lf2) numbered two or more per one centimeter of mucosa in the pyloric gland area of the lesser curvature, twenty specimens out of the 84 (24%) fit that definition. All of the FG cases were H.pylori positive, and they displayed high H.pylori scores. It was supposed that most FG cases would ultimately lead to atrophic gastritis, whereas H.pylori would gradationally decrease or disappeare in accordance with the aging and progression of intestinal metaplasia. The histological features of the FG cases, however, were similar to the background mucosal state of early-stage MALT-type gastric lymphoma. We may conclude that H.pylori infection is one cause of the FG, which may be a high-risk condition that gives rise to MALT-type gastric lymphoma.departmental bulletin pape