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Get PDFThe establishment of a correct working length is one of the fundamental parameters for endodontic success. Traditionally this has been determined using radiography, but electronic apex locators are increasingly being used. Electronic apex locators reduce the number of radiographs required and assist where radiographic methods create difficulty. The use of an electronic apex locator in combination with the radiograph is greater precision in the determination of root canal length. The aim of this paper is to review the electronic determination of the length of the root canal.departmental bulletin pape
Get PDFApoptosis of granulosa cells (GC) contributes to ovarian follicular atresia, and has been implicated to depend on the oxidant status of GC within follicles. Here, we investigated the effects of cAMP and prostaglandin E2 (PGE2) on sensitivity to oxidative stress using 4B2 cells with cAMP-dependent, steroidogenic and differentiated properties. This cell line was isolated from mouse GC co-transfected with genes for SV40 large T antigen and Ad4BP/SF1 transcription factor (Kamei et al. 2005). Treatment of serum-starved cells with 8-Br-cAMPcaused 30 to 40% of the cells to become polygonal within 2 h through actin rearrangement. Interestingly, H2O2 treatment showed that these polygonal cells were vulnerable to oxidative stress that led to cell death, which was inhibited by pretreatment with phalloidin, an F-actin stabilizing agent. Although PGE2 alone had no effect, cotreatment with PGE2 and 8-Br-cAMP completely inhibited the effects of 8-Br-cAMP on cell shape change and oxidative stress vulnerability through phosphatidylinositol 3-kinase (PI3K)-dependent manner. Notably, PGE2 and 8-Br-cAMP cooperated additively to increase progesterone secretion. These data suggest that cAMP signaling in GC may enhance oxidative stress risk through actin rearrangement, and PGE2 may reduce such risk through activating PI3K, while cooperating with cAMP signaling in steroidogenesis.departmental bulletin pape
Get PDFWe have been investigating and developing a color-changeable chewing gum，that tends not to adhere to dentures. The aim of this study was to investigate the color change of the chewing gum comparing to other methods while evaluating post-insertion changes of masticatory performance of complete denture wearers. Color-changeable chewing gum, the peanuts sieve test, a patient satisfaction questionnaire and a food questionnaire were applied to 26 edentulous subjects. The subjects were tested on two occasions: with previous dentures, with new dentures when they had no symptoms after finishing denture adjustment. In comparison between the differences of previous and new dentures, significant correlations were found between the color change of the chewing gum and the scores of patient satisfaction questionnaires and food questionnaire. It was suggested that this chewing gum was useful for an objective masticatory evaluation of the denture wearers and could contribute to prosthetic treatments according to patients' satisfaction for dentures, which is clinically important information for both patients and dentists.departmental bulletin pape
Get PDFWhile many studies reported the structural changes in the periodontal ligament (PDL) under hypofunctional conditions, the associations of cytokine growth factors are still unclear. They are known to take part in inflammation, and may affect the biological properties of hypofunctional tooth. To investigate the hypofunctional PDL and the recovery from this condition, we focused on interleukin-1 beta (IL-1β) and basic fibroblast growth factor (FGF-2). Male Wistar rats were divided into occluded, non-occluded, and recovery groups. An anterior bite plate was used to eliminate the occlusal contact of molars in the non-occluded group, and was then removed for the recovery group. After occlusal stimuli were eliminated for 7 and 14 days, and after 3 and 7 days of recovery from 7 days in the hypofunctional condition, the PDLs of the lower first molars were investigated immunohistochemically. The lack of occlusal stimuli caused atrophic changes in the PDL with the upregulation of IL-1β and decreased expression of FGF-2, while decreased IL-1β and enhanced FGF-2 expression were observed in the recovery process. These results suggest that occlusal stimuli regulate IL-1β and FGF-2 expression, and the nature of this regulation may differ from that in the healing process of an inflammatory reaction.departmental bulletin pape
Get PDFBiomechanical and biochemical factors are involved in bone remodeling. Occlusal loading is a well-known mechanical modulator of alveolar bone remodeling. Neuropeptides, such as vasoactive intestinal peptide (VIP) and calcitonin generelated peptide (CGRP), have been described within the biochemical bone regulators. In this study, the influences of occlusal loading on the alveolar bone remodeling and the distribution of VIP- and CGRP-immunoreactive (IR) fibers were investigated 1, 3 and 5 days after tooth replantation in rats. At day 5, occlusal loading induced a significant increase (p<0.05) in osteoclast number and osteoblast surface compared to those in the nonoccluded group. VIP-IR fibers were observed beside osteoblastic layers and their distribution was significantly enhanced (p<0.05) at day 5 in the occluded group, compared to the non-occluded group. Although there was immunoreactivity for CGRP in the periodontal ligament and alveolar bone apically, CGRP-IR fibers were not detected above the furcation. These results suggest that, after tooth replantation in rats, occlusal loading induced an increase in osteoclast and osteoblast formation, and that VIP might play a functional role in osteoblasts.departmental bulletin pape
Get PDFBackground: Homer, known as a scaffolding protein that regulates postsynapse signaling in neurons, has been poorly explored in cardiac research. We show the fundamental properties of Homer 1 in mouse heart in association with cardiac ryanodine receptor (RyR), a binding protein ofHomer 1. Methods and results: Immunohistochemistry of adult mouse heart with Homer 1 antibody showed striated staining on Z-bands both in atria and ventricles. The interactions between Homer 1 and RyR were confirmed by co-immunoprecipitation assays. Immunostaining of adult isolated cardiomyocytes showed partial co-localization of both proteins. In neonatal primary cultures, targeting of Homer 1 preceded that of RyR in their Z-band arrangement. Conclusions: Homer 1 binds to RyR in adult mouse heart and precedes RyR in Z-band arrangement in the early postnatal period.departmental bulletin pape
Get PDFMost ovarian follicles degenerate in a process called atresia, but the precise mechanisms behind this process remain unclear. We have investigated the roles of cyclooxygenase-2 and prostaglandin E2 in the atresia of preovulatory follicles in immature rats primed with pregnant mare's serum gonadotropin. Massive atresia was histologically confirmed to occur in preovulatory follicles of control rats. In contrast, administration of NS398, a specific cyclooxygenase-2 inhibitor, caused luteinization resulting in development of apparently normal corpora lutea and also atypical membranous corpora lutea. Progesterone secretion was high in the plasma of these rats, indicating that the corpora lutea were functional. These data suggest that cyclooxygenase-2 may be involved in determining whether the fate of preovulatory follicles will be atresia or luteinization.departmental bulletin pape
Get PDFThe purpose of this study was to investigate changes in the periodontal masseteric reflex (PMR) after experimentally induced occlusal hypofunction. Wistar rats were divided into control groups (CGs) and hypofunction groups (HGs). Rats in the HGs had their lower incisors cut down every other day for 6 weeks. Electrical stimulation was given to the periodontal ligaments of an upper incisor or the left trigeminal mesencephalic nucleus (MeV) in the CGs and HGs. Recordings of masseter motor unit responses were performed at 0, 1, 2, 4 and 6 weeks after hypofunction. Compared with the CGs, significant longer latencies in the PMR were found in the 4w- and 6w- HGs. After MeV stimulation, no significant difference in latency was found between HGs and CGs. After periodontal stimulation, the threshold value of masseteric motor-unit responses was higher in HGs than in CGs in 4and 6 weeks respectively. These results suggest that the PMR can be changed by periodontal sensory modification during occlusal hypofunction.departmental bulletin pape
Get PDFObjective: To determine the prevalence of comorbid depression among people with type 2 diabetes using the integrated health database. Methods: A total of 6543 people aged 18-65 years were selected from the employees of a Japanese corporation. Using the corporation's integrated health database, which consisted of medical claims data and a self-reported questionnaire from the fiscal year 2000, this study was undertaken to identify the prevalence, the odds ratio and some related factors. Results: The prevalence of co-morbid depression among people with type 2 diabetes was 2.6%. The crude odds ratio of co-morbid depression among those with type 2 diabetes was 2.20 (95% CI 0.88-5.50). After adjustment for covariates (gender, age, alcohol drinking, smoking, exercise, and dietary restriction), the odds ratio of co-morbid depression among those with type 2 diabetes was 2.33 (0.86-6.33). Conclusions: Using the integrated health database, it was suggested that patients with type 2 diabetes were more likely to suffer from depression and there was a relationship between depression and dietary restriction of portion control.departmental bulletin pape
Get PDFThe regional discrepancies of physician supply have been a growing concern in Japan. To find out how hospitals are responding in terms of physician payment (by monthly salaries and additional benefits), we conducted a survey of acute care hospitals in Yamagata, Japan. We asked about the salary and additional benefits of full-time physicians and the structural and functional characteristics of health care service provision. From these data we set out to assemble a model that can explain effectively the variability of physician payment in acute care hospitals within the prefecture. We found that physician payment was associated with variables such as type of management, staff employed per bed, full time doctors employed per bed and average length of stay. Hospital location was found to have a significant effect on payment. Variable sexpressing workload, like number of in-patients per doctor and number of surgical operations per doctor were inversely related. Our results suggest that hospitals may have adapted to physician preferences of workplace in terms of physician payment. To further address the problems of unbalanced geographic distribution of physicians in rural areas, work-sharing and educational and technical support schemes may also help.departmental bulletin pape