281 research outputs found

    <臨床>骨巨細胞腫に対する CEMENTATION の経験

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    骨巨細胞腫は, 病理学的には良性であるが, その局所における aggressive さに加え, まれに転移をおこすこともあり, その生物学的態度は必ずしも良性とは言い難い. また, 関節近傍に発生することから, 治療法の選択に迷うことも少なくない. 我々は, 1986年から主としてstage1, 2 の GCT に対して CEMENTATION を施行してきたが, 今回その術後成績を評価しその有用性について検討した. 対象は, 11 例の GCT で, 男6例, 女5例であり, 発生部位は大腿骨遼位8例, 脛骨近位2例, 上腕骨近位が1例であった. 術後経過観察期聞は8ヶ月から72ヶ月, 平均42ヶ月であった. 術後機能評価を Enneking の modified functional evaluation system を用いて行った excellent 6例, good 4例, fairl 1例であり, また, 合併症としては, 術後に1例骨折がみられたが, 保存療法で治癒した. 少数のシリーズであり, 経過観察期間も長期ではないが, CEMENTATION は stage1 および stage2 の GCT に対する第一選択の治療法であると評価できた

    Earth Magnetosphere Model Investigations for Coupled Orbit-Attitude Space Debris Perturbations

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    As more objects are placed into orbit, collisions become increasingly more likely, leading to a so-called Kessler Syndrome: collisions between existing debris creates more debris, causing a cascading effect of larger amounts of debris being put into orbit, even in the absence of launches, making future space fairing difficult or impossible. Natural forces influence the orbit and attitude of uncontrolled debris objects. The natural plasma environment can lead to space object charging. The subsequent orbital movement in the geomagnetosphere induces Lorentz forces that act both on the orbit and attitude of the space object. Those forces have not been investigated thoroughly so far. Current physics-based models of the Earth\u27s magnetosphere examine the influence of the Sun\u27s corona and the Earth\u27s ionosphere on the plasma. This study looks at focusing the magnetosphere models in the near Earth region, specifically from low Earth orbit up to an altitude of 36000 km, to decrease computation time without significantly lowering the accuracy in the region of interest. The models that this study examines are a dipole, multipole, and multipole with plasma dynamics. The position of a charge deviates on the order of micrometers when comparing results from a dipole model and 7th degree multipole model

    Special Relativistic Magnetohydrodynamic Simulation of Two-Component Outflow Powered by Magnetic Explosion on Compact Stars

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    The nonlinear dynamics of outflows driven by magnetic explosion on the surface of a compact star is investigated through special relativistic magnetohydrodynamic simulations. We adopt, as the initial equilibrium state, a spherical stellar object embedded in hydrostatic plasma which has a density ρ(r)rα\rho(r) \propto r^{- \alpha} and is threaded by a dipole magnetic field. The injection of magnetic energy at the surface of compact star breaks the equilibrium and triggers a two-component outflow. At the early evolutionary stage, the magnetic pressure increases rapidly around the stellar surface, initiating a magnetically driven outflow. A strong forward shock driven outflow is then excited. The expansion velocity of the magnetically driven outflow is characterized by the Alfv\'en velocity on the stellar surface, and follows a simple scaling relation vmagvA1/2v_{\rm mag} \propto {v_{\rm A}}^{1/2}. When the initial density profile declines steeply with radius, the strong shock is accelerated self-similarly to relativistic velocity ahead of the magnetically driven component. We find that it evolves according to a self-similar relation Γshrsh\Gamma_{\rm sh} \propto r_{\rm sh}, where Γsh\Gamma_{\rm sh} is the Lorentz factor of the plasma measured at the shock surface rshr_{\rm sh}. Purely hydrodynamic process would be responsible for the acceleration mechanism of the shock driven outflow. Our two-component outflow model, which is the natural outcome of the magnetic explosion, can provide a better understanding of the magnetic active phenomena on various magnetized compact stars.Comment: Accepted for publication in ApJ. 15 pages, 2 tables, 17 figure

    High-speed simulation of PCB emission and immunity with frequency-domain IC/LSI source models

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    Some recent results from research conducted in the EMC group at Okayama University are reviewed. A scheme for power-bus modeling with an analytical method is introduced. A linear macro-model for ICs/LSIs, called the LECCS model, has been developed for EMI and EMS simulation. This model has a very simple structure and is sufficiently accurate. Combining the LECCS model with analytical simulation techniques for power-bus resonance simulation provides a method for high-speed EMI simulation and decoupling evaluation related to PCB and LSI design. A useful explanation of the common-mode excitation mechanism, which utilizes the imbalance factor of a transmission line, is also presented. Some of the results were investigated by implementing prototypes of a high-speed EMI simulator, HISES. </p

    Establishment of a new rehabilitation program using masticatory training food for jaw deformity patients

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    Background/purpose: Patients with jaw deformities may show a reduction in masticatory function as a result of postoperative hypofunction. This study aimed to establish a novel rehabilitation program using a commercially available masticatory training food for patients with jaw deformities after orthognathic surgery. Materials and methods: Nine patients with mandibular prognathism (the training group: n = 5, and the non-training group: n = 4) and 6 control participants with normal occlusion were included in this study. For the rehabilitation program with masticatory exercise, patients were instructed to chew the training food once a day for 60 days starting from 10 days after the surgery. The effects of the rehabilitation program were assessed by determining the maximum bite force (MBF) and the masticatory performance (MP). Clinical assessments were performed just before orthognathic surgery (Pre) and at 10 days (T0), 1 month (T1), 2 months (T2), and 3 months (T3) after surgery. Results: Compared with the non-training group, the training group showed a trend toward greater recovery amount of MBF from Pre to T3, and a significantly greater recovery amount in MP (p < 0.05) from Pre to T3. When the time-series change of MP was evaluated in both groups from T0 to T3, a significant difference was observed in the interaction terms (p = 0.03). This result indicates that the effectiveness of the training may be demonstrated by following the postoperative course further. Conclusion: The rehabilitation using this training food may become a useful method for postoperative hypofunction in patients with jaw deformities

    Functional training after orthognathic surgery

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    Background/purpose: Even after surgical orthodontic treatment, the level of masticatory function in patients with jaw deformities is still lower than that of healthy subjects. The purpose of this study was to evaluate the effects of functional training program using gum chewing exercise after orthognathic surgery on masticatory function in patients with mandibular prognathism. Materials and methods: The study subjects were 16 patients with mandibular prognathism who underwent orthognathic surgery and 8 individuals with normal occlusion. Patients were divided into two groups (training group and non-training group; n = 8 per group). Functional training included gum chewing exercise and patient-education about masticatory function. The training; gum chewing exercise of 5 min twice a day for 90 days, started at 3 months after surgery. For each subject, electromyographic activities of masseter and temporalis muscles during maximum voluntary clenching (MVC) and jaw movement during gum chewing were recorded before and after surgical orthodontic treatment. Two parameters; activity index (AI: ratio of activity of masseter and temporalis muscles) and error index (EI: ratio of the number of abnormal chewing patterns), were used. Results: In the training group, the AI value during MVC increased significantly and the EI value during gam chewing decreased significantly after surgical orthodontic treatment (AI: p < 0.01; EI: p < 0.01), indicating the improvement of activity balance of masseter and temporalis muscles and conversion of the jaw movement from abnormal to normal pattern (p < 0.01). Conclusion: Our findings suggested that functional training using the gum chewing and patient-education exercise improved masticatory function in patients with mandibular prognathism

    Treatment decision of camouflage or surgical orthodontic treatment for skeletal Class III patients based on analysis of masticatory function

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    Background/purpose: Surgical orthodontic treatment is recommended for patients with severe dentoskeletal discrepancies, while camouflage orthodontic treatment is recommended for patients with mild to moderate discrepancies. However, the decision as to which treatment should be chosen is complicated. The purpose of this study was to determine differences in masticatory function in patients who underwent camouflage and surgical orthodontic treatment for skeletal Class III malocclusion, as well as the usefulness of Wits appraisal in treatment decision based on masticatory functional analysis. Materials and methods: The study subjects were 45 patients with skeletal Class III malocclusion (15 cases with camouflage orthodontics and 30 cases with orthognatic surgery) and 12 individuals with normal occlusion. We analyzed the pre-treatment records of electromyographic activities of masseter and temporalis muscles and jaw movements. Results: There were no significant differences in various functional measurements between the camouflage and surgery groups. However, there were significant but not strong correlations between ANB and both masseter muscle activity (r = 0.36, p < 0.01) and expression ratio of abnormal chewing (r = −0.54, p < 0.01). Division of patients into two groups using a cutoff value of −6.0 mm for Wits appraisal showed a significant difference in masseter muscle activity between −6.0 mm or less group and the control (p < 0.01) but none between more than −6.0 mm group and the control. Conclusion: Camouflage orthodontic treatment is inappropriate for patients with relatively severe dentoskeletal discrepancies. Wits appraisal of −6.0 mm is a potentially useful parameter for treatment decision

    Neurologic Abnormalities in Workers of a 1-Bromopropane Factory

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    We reported recently that 1-bromopropane (1-BP; n-propylbromide, CAS Registry no. 106-94-5), an alternative to ozone-depleting solvents, is neurotoxic and exhibits reproductive toxicity in rats. The four most recent case reports suggested possible neurotoxicity of 1-BP in workers. The aim of the present study was to establish the neurologic effects of 1-BP in workers and examine the relationship with exposure levels. We surveyed 27 female workers in a 1-BP production factory and compared 23 of them with 23 age-matched workers in a beer factory as controls. The workers were interviewed and examined by neurologic, electrophysiologic, hematologic, biochemical, neurobehavioral, and postural sway tests. 1-BP exposure levels were estimated with passive samplers. Tests with a tuning fork showed diminished vibration sensation of the foot in 15 workers exposed to 1-BP but in none of the controls. 1-BP factory workers showed significantly longer distal latency in the tibial nerve than did the controls but no significant changes in motor nerve conduction velocity. Workers also displayed lower values in sensory nerve conduction velocity in the sural nerve, backward recalled digits, Benton visual memory test scores, pursuit aiming test scores, and five items of the Profile of Mood States (POMS) test (tension, depression, anxiety, fatigue, and confusion) compared with controls matched for age and education. Workers hired after May 1999, who were exposed to 1-BP only (workers hired before 1999 could have also been exposed to 2-BP), showed similar changes in vibration sense, distal latency, Benton test scores, and depression and fatigue in the POMS test. Time-weighted average exposure levels in the workers were 0.34–49.19 ppm. Exposure to 1-BP could adversely affect peripheral nerves or/and the central nervous system

    The dopamine D1 receptor is expressed and induces CREB phosphorylation and MUC5AC expression in human airway epithelium

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    Background Dopamine receptors comprise two subgroups, Gs protein-coupled “D1-like” receptors (D1, D5) and Gi-coupled “D2-like” receptors (D2, D3, D4). In airways, both dopamine D1 and D2 receptors are expressed on airway smooth muscle and regulate airway smooth muscle force. However, functional expression of the dopamine D1 receptor has never been identified on airway epithelium. Activation of Gs-coupled receptors stimulate adenylyl cyclase leading to cyclic AMP (cAMP) production, which is known to induce mucus overproduction through the cAMP response element binding protein (CREB) in airway epithelial cells. We questioned whether the dopamine D1 receptor is expressed on airway epithelium, and whether it promotes CREB phosphorylation and MUC5AC expression. Methods We evaluated the protein expression of the dopamine D1 receptor on native human airway epithelium and three sources of cultured human airway epithelial cells including primary cultured airway epithelial cells, the bronchial epithelial cell line (16HBE14o-), and the pulmonary mucoepidermoid carcinoma cell line (NCI-H292) using immunohistochemistry and immunoblotting. To characterize the stimulation of cAMP through the dopamine D1 receptor, 16HBE14o- cells and NCI-H292 cells were treated with dopamine or the dopamine D1 receptor agonists (SKF38393 or A68930) before cAMP measurements. The phosphorylation of CREB by A68930 in both 16HBE14o- and NCI-H292 cells was measured by immunoblot. The effect of dopamine or A68930 on the expression of MUC5AC mRNA and protein in NCI-H292 cells was evaluated by real-time PCR and immunofluorescence staining, respectively. Results The dopamine D1 receptor protein was detected in native human airway epithelium and three sources of cultured human airway epithelial cells. Dopamine or the dopamine D1-like receptor agonists stimulated cAMP production in 16HBE14o- cells and NCI-H292 cells, which was reversed by the selective dopamine D1-like receptor antagonists (SCH23390 or SCH39166). A68930 significantly increased phosphorylation of CREB in both 16HBE14o- and NCI-H292 cells, which was attenuated by the inhibitors of PKA (H89) and MEK (U0126). Expression of MUC5AC mRNA and protein were also increased by either dopamine or A68930 in NCI-H292 cells. Conclusions These results suggest that the activation of the dopamine D1 receptor on human airway epithelium could induce mucus overproduction, which could worsen airway obstructive symptoms
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