Soft tissue artefact (STA) is caused by the relative displacement of markers or sensors mounted on the skin surface with respect to the underlying bones, and is a major source of error in the kinematic measurement of human movement. In particular, the humeral axial rotation (HAR) is affected by STA. The aim of this study was to propose a method for compensating for STA and to validate its effectiveness. In the proposed method, the HAR angle was calculated by a second-order regression using three independent variables converted from the Cardan angles of the shoulder joint. The calculated HAR angle (HAR-r) was compared with the angle calculated from the direction of the longitudinal axis of the forearm (HAR-f). Highly linear correlations were found between HAR-r and HAR-f when the elbow joint was flexed at 90°. The elbow flexion/extension motion had little influence on the HAR-r, whereas HAR-f became unstable when the elbow joint approached its full extension. Because HAR-r effectively compensates for the STA and is independent of the elbow flexion/extension, the regression method is suitable for the movement analysis of the upper limbs.

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People have the opportunity to inhale inorganic dusts under various environments. Inorganic dust exposures as a result of occupational exposure may induce or modulate pulmonary fibrosis. We analyzed the deposition of elements in lung tissues of patients with idiopathic pulmonary fibrosis (IPF) and compared element deposition with chronic hypersensitivity pneumonitis (chronic HP) and collagen vascular diseases (CVD). Thirty-five patients (18 men and 17 women with the mean age of 64.3) were studied, including 15 IPF, 8 chronic HP, 6 CVD, and 6 control patients. Four IPF patients have occupational dust exposures. Inorganic particles were counted by polarizing light microscopy and scanning electron microscopy. Energy dispersive X-ray spectroscopy was performed to analyze an elemental deposition. The number of birefringent particles was greater in IPF, even in IPF without occupational exposure, than in controls. The silicon (Si) / sulfur (S) ratio and aluminium (Al) / S ratio were increased in IPF independent of occupational exposure. A point elemental analysis showed that the major compound of the particles was aluminium -silicate in IPF. These results suggest that unrecognized dust exposures are relatively common in some IPF patients and aluminium-silicate could be associated with the disease process of IPF.

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The purpose of this in vitro study was to investigate the effect of hardness on the reduction of stress transferred to tissues around implants using a resilient material applied to the female parts of the ball attachment in maxillary implant overdentures. A cast chrome-cobalt framework was mounted onto a maxillary acrylic edentulous model, which contained two implants and four strain gauges attached to the implant. Ball abutments were screwed into the implant. One abutment was connected to a dedicated metal cap embedded in the housing, while the others were connected to resilient test materials with four different hardnesses. Loads were applied using a universal testing machine with a magnitude of 50 N. The sums of the absolute values recorded from the four strain gauges were used for stress evaluation. The measured strains were analyzed statistically using two-way ANOVA and multiple comparisons. A resilient material with hardness 90 exhibited strains that did not differ significantly from the control. In contrast, the other resilient materials showed significantly reduced strains under all conditions. In this limited study, application of resilient silicone materials with approximate hardness 80 to the female parts of ball attachments significantly reduced the stress on the tissues around the implant.

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Specific areas of cortical activity during solid bolus swallowing in humans are unknown. We tested the hypothesis that cortical representations of swallowing in humans may vary by bolus type. Twenty-one normal subjects swallowed three kinds of food: agar (solid), a capsule and water. We followed the same countdown method for identification of the cortical representations during swallowing performances as a previous study (Tanaka et al., 2006). Functional magnetic resonance imaging (fMRI) showed that the precentral gyrus, postcentral gyrus, medial temporal gyrus, superior temporal gyrus and cingulate gyrus were activated when swallowing an agar bolus (p<0.001). The subcortex was not activated. The cerebellum was activated only during capsule swallowing (P<0.001). Water bolus swallowing activations were similar to agar bolus swallowing. The cluster size of water swallowing was larger than the agar swallowing. We conclude that the cortical representations for swallowing are variable by food type.

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The 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.

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Objective: 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.

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Biomechanical 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.

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The 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. Variables expressing 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.

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We 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.

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While 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.

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Temporomandibular disorders (TMD) are known to be more prevalent and severe in women than in men, especially in those who are in their reproductive age. In those patients reproductive hormones may play a vital role in the host adaptive capacity of the temporomandibular joint (TMJ). In order to clarify the relationship between TMD prevalence and estrogen cycle, a mandible deviated animal model was carried out, and the expression of inducible nitric oxide synthase (iNOS), an essential enzyme in the pathogenesis of inflammatory arthritis, was investigated in the rat’s synovial tissue. An appliance was attached to the rat’s incisors to produce a lateral deviation of the mandible during the metestrus phase, and the animals were sacrificed in the proestrus and estrus phase, when the estrogen was at the highest and lowest level, respectively. Immunostaining was then performed for 2 consecutive estrous cycles to demonstrate iNOS expression in the synovial membrane of the TMJ. The immunoreactivity for iNOS was more intense in the synovial membrane on the contralateral side in the proestrus phase (estrogen peak phase). These observations suggest that iNOS expression in the synovial membrane with mandibular deviation may be exacerbated in the presence of estrogen.

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Previous reports suggested that cigarette smoke had a protective effect of on the development of hypersensitivity pneumonitis (HP). However, smoking rate in chronic pigeon breeder’s lung (PBL) seemed to be high in our clinical experiences. We developed a murine model of PBL by intranasal instillation with pigeon dropping extracts (PDE) for 4 weeks (short-term exposure) and 17 weeks (long-term exposure) to investigate the effect of cigarette smoke on disease processes. In this model, lung inflammation associated with the production of anti-PDE antibodies and antigen dependent lymphocyte proliferation was induced. Long-term exposure to PDE without cigarette smoking resulted in an increase in lung weight / body weight ratio, total cell number in bronchoalveolar lavage (BAL) fluid, and content of hydroxyproline in the lung compared to shortterm exposure. After a short-term exposure, cigarette smoke lessened the lymphocytosis in BAL fluid, and lymphocyte proliferation. On the other hand, after a long-term exposure cigarette smoke increased lung hydroxyproline. These results suggest that a short-term cigarette smoking attenuates lung inflammation, but a long-term cigarette smoking enhances lung inflammation with fibrosis.

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Transient alkalization caused by activation of the BK_Ca channels has been reported to be essential for the activation of proteolytic enzymes and bacterial killing in the leukocytic phagosomes. We investigated the effects of high glucose concentrations on these processes in THP-1 cells. While E.coli transiently raised the pH of the phagosomes in THP-1 monocytes, high glucose concentrations impaired the transient rise of pH in a dose-and time-dependent manner. Electrophysiological studies confirmed that the bacteria elicited a transient K⁺ current, and that a high glucose concentration diminished the current. High glucose concentrations also inhibited the activation of cathepsin G in the THP-1 cells. NS1619, a BK_Ca channel opener, accentuated the transient alkalization induced by the bacteria, and reversed the inhibitory effect of high concentrations of glucose. However, electrophysiological study revealed that the membrane current differed from the BK_Ca current. Our findings indicate that high glucose concentrations impair K⁺ channel activation and the subsequent activation of proteolytic enzymes in THP-1 monocytes. The precise identity of the K⁺ channel remains unclear, although it dose not appear to be the BK_Ca. Suppression of the transient alkalization and activation of proteases may be one of the mechanisms for bacterial killing by phagocytes in diabetic patients.

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Background: 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 of Homer 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.

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We studied the effect of cigarette smoke extract (CSE) on a three-dimensional (3-D) co-culture model with epithelial cells and mesenchymal cells to clarify how epithelial cells protect lung tissue from cigarette smoke in-vivo. Two types of gels were prepared. The one was the co-culture of human fetal lung fibroblasts (HFL-I) embedded in type-I collagen gel, with alveolar epithelial cells (A549) cultured covering the top of the gel. The other was HFL-I cells alone. After 48 hours from CSE exposure, gel contraction, levels of fibronectin, transforming growth factor (TGF)--β1 and GSH were assessed. CSE inhibited fibroblast-mediated gel contraction and this inhibition was lessened in co-culture associated with higher GSH concentration and TGF--β1 level as compared to the level in HFL-I cells alone. CSE lowered fibronectin level to a lesser extent in co-culture as compared to the level in HFL-I cells alone. Exogenous TGF--β1 restored the inhibition of gel contraction by CSE independent of GSH level. Cigarette smoke may interfere with 3-D co-culture gel contraction by diminishing GSH, fibronectin and TGF--β1 action in the epithelial-mesenchymal interaction.

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