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Ihara Y, Hirano A, Endo S, Kobayashi H, Torisu T. Gastrointestinal: A case of zonisamide-induced esophageal and small intestinal injury. J Gastroenterol Hepatol 2019; 34:1671. [PMID: 31119767 DOI: 10.1111/jgh.14685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 04/17/2019] [Indexed: 12/09/2022]
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Yogo R, Yamaguchi Y, Watanabe H, Yagi H, Satoh T, Nakanishi M, Onitsuka M, Omasa T, Shimada M, Maruno T, Torisu T, Watanabe S, Higo D, Uchihashi T, Yanaka S, Uchiyama S, Kato K. The Fab portion of immunoglobulin G contributes to its binding to Fcγ receptor III. Sci Rep 2019; 9:11957. [PMID: 31420591 PMCID: PMC6697678 DOI: 10.1038/s41598-019-48323-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/02/2019] [Indexed: 12/12/2022] Open
Abstract
Most cells active in the immune system express receptors for antibodies which mediate a variety of defensive mechanisms. These receptors interact with the Fc portion of the antibody and are therefore collectively called Fc receptors. Here, using high-speed atomic force microscopy, we observe interactions of human, humanized, and mouse/human-chimeric immunoglobulin G1 (IgG1) antibodies and their cognate Fc receptor, FcγRIIIa. Our results demonstrate that not only Fc but also Fab positively contributes to the interaction with the receptor. Furthermore, hydrogen/deuterium exchange mass spectrometric analysis reveals that the Fab portion of IgG1 is directly involved in its interaction with FcγRIIIa, in addition to the canonical Fc-mediated interaction. By targeting the previously unidentified receptor-interaction sites in IgG-Fab, our findings could inspire therapeutic antibody engineering.
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Torisu T, Maruno T, Hamaji Y, Ohkubo T, Uchiyama S. Synergistic Effect of Cavitation and Agitation on Protein Aggregation. J Pharm Sci 2017; 106:521-529. [DOI: 10.1016/j.xphs.2016.10.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/27/2016] [Accepted: 10/13/2016] [Indexed: 12/19/2022]
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Taira H, Takasita M, Yoshida S, Takita C, Tsumura H, Torisu T. MR appearance of paraganglioma of the cauda equina: Case reports. Acta Radiol 2016. [DOI: 10.1258/rsmacta.41.1.27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose: To investigate the value of MR imaging for preoperative diagnosis of paraganglioma of the cauda equina. Material and Methods: A retrospective review of 2 cases of paraganglioma of the cauda equina examined with MR imaging was undertaken. Features assessed included the homogeneity of the lesions, presence or absence of serpiginous flow void and thin hypointense margins. Results: In case 1, the tumor was hyperintense on the postcontrast examination and serpiginous flow void suggested vessels in the upper pole of the tumor. In case 2, the tumor was encapsulated by a thin hypointense margin on both T1- and T2-weighted images, which suggested hemosiderin. Conclusion: The MR appearance may be of great value in the preoperative diagnosis of paraganglioma of the cauda equina.
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Torisu T, Torisu K, Lovren F, Pan Y, Pankova N, Boyd S, Verma S, Finkel T. ENDOTHELIAL AUTOPHAGY REGULATES CHOLESTEROL TRANSPORT AND IS A NOVEL REGULATOR OF ATHEROSCLEROSIS. Can J Cardiol 2014. [DOI: 10.1016/j.cjca.2014.07.507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Kudo O, Fujikawa Y, Hirayama T, Torisu T. Osteoclast differentiation factor induces synovial macrophage-osteoclast differentiation in rheumatoid arthritis. Mod Rheumatol 2014; 11:314-20. [PMID: 24383776 DOI: 10.3109/s10165-001-8062-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract The aim of this study was to clarify the role of osteoclast differentiation factor (ODF) and osteoprotegerin (OPG) in synovial macrophage-osteoclast differentiation. Synovial macrophages were cultured in the presence of macrophage-colony-stimulating factor (M-CSF) and/or ODF. OPG was added to cocultures of synovial macrophages and UMR106. The cultures on glass coverslips were stained with osteoclast-associated markers, tartrate-resistant acid phosphatase (TRAP), and vitronectin receptor (VNR), as well as macrophage-associated markers CD11b and CD14. Functional evidence of osteoclast formation was determined by a resorption pit assay. To investigate whether rheumatoid arthritis (RA) synovial cells expressed messenger RNA (mRNA) for ODF, OPG, and the receptor activator of NF-κB (RANK), we performed a polymerase chain reaction (PCR) analysis. The addition of M-CSF or ODF alone induced TRAP-positive multinucleated cell formation. Resorption pits were rarely detected with M-CSF alone. ODF was capable of inducing bone resorption and enhancing osteoclastogenesis, as well as bone resorption in the presence of M-CSF. In the coculture system, both osteoclast formation and bone resorption were inhibited by OPG in a dose-dependent manner. In all experiments, synovial cells, including macrophages and fibroblasts, expressed the mRNA for RANK, ODF, and OPG. Our findings suggest that ODF plays a role in regulating RA synovial macrophage-osteoclast differentiation, and that synovial cells might have the ability to produce ODF. OPG might be further developed as a new strategy for treating bone destruction in RA joints.
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Shimada A, Yamabe Y, Torisu T, Baad-Hansen L, Murata H, Svensson P. Measurement of dynamic bite force during mastication. J Oral Rehabil 2012; 39:349-56. [PMID: 22288929 DOI: 10.1111/j.1365-2842.2011.02278.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Efficient mastication of different types and size of food depends on fast integration of sensory information from mechanoreceptors and central control mechanisms of jaw movements and applied bite force. The neural basis underlying mastication has been studied for decades but little progress in understanding the dynamics of bite force has been made mainly due to technical limitations of bite force recorders. The aims of this study were to develop a new intraoral bite force recorder which would allow the study of natural mastication without an increase in the occlusal vertical dimension and subsequently to analyze the relation between electromyographic (EMG) activity of jaw-closing muscles, jaw movements and bite force during mastication of five different types of food. Customized force recorders based on strain gauge sensors were fitted to the upper and lower molar teeth on the preferred chewing side in fourteen healthy and dentate subjects (21-39 years), and recordings were carried out during voluntary mastication of five different kinds of food. Intraoral force recordings were successively obtained from all subjects. anova showed that impulse of bite force as well as integrated EMG was significantly influenced by food (P<0·05), while time-related parameters were significantly affected by chewing cycles (P<0·001). This study demonstrates that intraoral force recordings are feasible and can provide new information on the dynamics of human mastication with direct implications for oral rehabilitation. We also propose that the control of bite force during mastication is achieved by anticipatory adjustment and encoding of bolus characteristics.
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Torisu T, Yamada K, Fukui T, Yamaki M, Nakamura J, Saito I. A cross-sectional study on the relationship between craniofacial morphology and the coronoid process. Eur J Orthod 2009; 31:613-9. [DOI: 10.1093/ejo/cjp043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Noguchi K, Fujii H, Yamabe Y, Tanaka M, Shimada A, Torisu T, Suenaga H. Anticipation and motor control on repetitive tooth tapping produced by open-close jaw movements. J Oral Rehabil 2008; 35:20-6. [PMID: 18190357 DOI: 10.1111/j.1365-2842.2007.01780.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study was designed to evaluate the relationship between the temporal anticipation effects and motor control on repetitive tooth tapping movements (tooth tapping produced by open-close jaw movements) commanded by six frequencies of acoustic signals. Ten dentulous young adults were asked to perform tooth tapping movements to acoustic command signals at constant frequencies of 0.3, 0.8, 1.3, 1.8, 2.3 and 2.8 Hz. Surface electromyograms of the Masseter muscles, vertical component of the Mandibular kinesiograph, and acoustic signals were simultaneously recorded. Some parameters were measured for tappings at the last signal (TL) and surplus tappings without signals after the last signal (TL(n)) in each frequency command signal. The results showed that changes in the strategy for tapping movement controls occurred between 0.3 and 0.8 Hz. Between 0.8 and 2.8 Hz, each tooth tapping was automatically initiated before the confirmation of the signal; initiation and control of repetitive tapping movements were apparently based on effector anticipation (predicting the duration of internal processes for a planned movement so that it can be made coincidental to some anticipated external event) and receptor anticipation (anticipation of the arrival of a stimulus due to sensory information about its time of arrival). However, at 0.3 Hz, the movement initiation was delayed, such that each tooth tapping was initiated after the confirmation of the signal. Therefore, tappings at 0.3 Hz showed less dependence on receptor anticipation. These changes in motor control strategy are considered to be a reasonable way to prevent incorrect movements and to minimize erroneous movements.
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Takata Y, Ansai T, Soh I, Kimura Y, Yoshitake Y, Sonoki K, Awano S, Kagiyama S, Yoshida A, Nakamichi I, Hamasaki T, Torisu T, Toyoshima K, Takehara T. Physical Fitness and Cognitive Function in an 85-Year-Old Community-Dwelling Population. Gerontology 2008; 54:354-60. [DOI: 10.1159/000129757] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 03/11/2008] [Indexed: 11/19/2022] Open
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Nakamura Y, Torisu T, Noguchi K, Fujii H. Changes in masseter muscle blood flow during voluntary isometric contraction in humans. J Oral Rehabil 2005; 32:545-51. [PMID: 16011632 DOI: 10.1111/j.1365-2842.2005.01461.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effect of jaw clenching on local blood flow in the masseter muscle was measured using the hydrogen clearance method in 13 healthy subjects. Sustained isometric masseter-muscle contraction levels of 25 and 50% of maximum voluntary contraction (MVC) were investigated. The blood flow at 25% MVC before contraction, during contraction and after contraction was 12.3 +/- 10.9, 19.2 +/- 12.1 and 78.8 +/- 63.9 mL min(-1) (100 g)(-1) (mean +/- s.d.), respectively. At 50% MVC, it was 14.2 +/- 12.9, 18.6 +/- 10.0 and 80.1 +/- 61.8, respectively. The volume of blood flow was significantly greater after contraction as compared with before contraction at both levels (P < 0.0001) and there was no significant difference between before and during contraction periods (P = 0.17: 25% MVC; P = 0.38: 50% MVC). At 50% MVC blood flow before contraction and the difference in blood flow before and during contraction showed significant negative correlation (r = -0.636, P < 0.02). When the volume of blood flow was low before contraction it tended to increase during contraction and decreased when it was high before contraction. These findings indicate that blood flow in the masseter muscle during sustained isometric contraction is affected by the condition of contraction and may be influenced by the muscle region. It was also indicated that the blood flow during high level contraction was influenced by the volume of blood flow before contraction. Clinically, our findings may help to understand pathological changes which may lead to chronic masticatory muscle pain.
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Sawatari T, Tsumura H, Iesaka K, Furushiro Y, Torisu T. Three-dimensional finite element analysis of unicompartmental knee arthroplasty--the influence of tibial component inclination. J Orthop Res 2005; 23:549-54. [PMID: 15885474 DOI: 10.1016/j.orthres.2004.06.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Indexed: 02/04/2023]
Abstract
Aseptic loosening and failure of a tibial component are recognized problems in unicompartmental knee arthroplasty (UKA). Excessive stress on the supporting cancellous bone is thought to contribute to the loosening and failure. Of factors that could influence supporting cancellous bone stresses, we focused on the inclination of a unicompartmental tibial component by analyzing the effect of coronal plane and sagittal plane inclination. Detailed geometrically accurate, three-dimensional finite element models were constructed from computed tomography (CT) data of a typical adult male proximal tibia. The material properties for the models were obtained directly from the CT data to simulate the inhomogeneous distribution of cancellous bone properties. Placing the component in slight valgus inclination in the coronal plane reduced the cancellous bone stresses. Posterior inclination in the sagittal plane caused a moderate increase in the stresses. Our results suggest that slight valgus inclination of a UKA tibial component may be preferable to varus or square inclination in the coronal plane. An excessive posterior slope of a tibial component should be avoided.
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Tsumura H, Kaku N, Torisu T. Does the self-centering mechanism of bipolar hip endoprosthesis really work in vivo? J Orthop Surg (Hong Kong) 2005; 13:46-51. [PMID: 15872400 DOI: 10.1177/230949900501300108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSES To examine radiographically the component motion in a bipolar prosthesis and to determine whether the self-centering mechanism really works in vivo. METHODS 38 patients with 41 bipolar hip endoprostheses (30 for coxarthrosis and 11 for osteonecrosis of femoral head) were included in this study. Two radiographs of each case were taken to evaluate the self-centering mechanism. The first anteroposterior radiograph of both hip joints was taken at the maximum abduction while the patient standing on the endoprosthetic leg. The second radiograph was taken after the patient returned to neutral position while standing on 2 legs. In the present study, the order in which the radiographs were taken differed from previously reported studies. The radiographs were analysed using the method similar to that of Drinker and Murray. The adductive motion from abduction to a neutral position is within the range of inner bearing oscillation. RESULTS The outer head alignment changed from 23 degrees to 12 degrees in the patients with osteonecrosis. However, the valgus position of the outer head (36 degrees) remained unchanged in the patients with coxarthrosis standing on 2 legs in the neutral position. CONCLUSION The self-centering mechanism of the bipolar endoprosthesis functioned in the patients with osteonecrosis, but did not work in the coxarthrosis group.
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Tsumura H, Ikeda S, Torisu T. Debridement and continuous irrigation for the treatment of pyogenic arthritis caused by the use of intra-articular injection in the osteoarthritic knee: indications and outcomes. J Orthop Surg (Hong Kong) 2005; 13:52-7. [PMID: 15872401 DOI: 10.1177/230949900501300109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To discuss the indications and therapeutic outcomes of synovectomy, debridement, and continuous irrigation for the treatment of pyogenic arthritis caused by intra-articular injection used in the treatment of osteoarthritis of the knee. METHODS Records of 41 patients with infectious arthritis of the knee who presented to our hospital from 1981 were reviewed. 11 of them had a history of intra-articular injection. They underwent synovectomy, debridement, and continuous irrigation using a Salem double-lumen tube after confirmation that one side of the femorotibial joint cartilage was basically healthy. RESULTS The infection was successfully treated in 9 of the 11 patients. Of these 9 patients, one died after 3 years and 2 underwent total knee arthroplasty after 3 and 8 years. The remaining 6 patients were followed up for 5 to 15 years. Five of them had deteriorating arthropathy, and the condition was unchanged in the others. Two of these 6 patients had pain while walking, and their Japanese Orthopaedic Association scores were 70. The remaining 4 had good knee function and reduction of pain, with a mean Japanese Orthopaedic Association score of 91 and a mean range of motion of 131 degrees. CONCLUSION Arthrodesis is frequently considered the treatment for osteoarthritis if the joint destruction has affected the weight-bearing surface. However, in our experience, even when inflammatory granulation develops in the cartilage surface of one side of the femorotibial joint, good results can still be obtained by synovectomy, debridement, and continuous irrigation. After the pyogenic arthritis has subsided, if osteoarthritis has advanced and bowleg has exacerbated, further treatment options are available, such as tibial resection and even joint replacement. Continuous irrigation should be considered a feasible treatment option for pyogenic arthritis.
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Torisu T, Kaku N, Tumura H, Taira H, Tomari K. 3M integral bipolar cup system for dysplastic osteoarthritis. Clinical and radiographic review with five- to seven-year follow-up. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 2003; 85:822-5. [PMID: 12931798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Between 1995 and 1997 we undertook 40 bipolar hip arthroplasties in 35 patients with dysplastic osteoarthritis. The steep and shallow acetabulum was excavated and the bipolar socket was placed high with an adjustment of leg-length. At follow-up of between five and seven years, there were 19 excellent, 16 good and five fair results according to the scoring system of Merle d'Aubigné and Postel. The mean radiographic superior migration of the bipolar socket was 2.1 mm (0 to 10). Osteolysis was noted in three hips within three years of the operation. Abduction on weight-bearing was recorded in 24 hips and the bipolar system was found to be functioning predominantly between the inner bearing and the metal femoral head in 20.
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Torisu T, Kaku N, Tumura H, Taira H, Tomari K. 3M integral bipolar cup system for dysplastic osteoarthritis. ACTA ACUST UNITED AC 2003. [DOI: 10.1302/0301-620x.85b6.14079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Between 1995 and 1997 we undertook 40 bipolar hip arthroplasties in 35 patients with dysplastic osteoarthritis. The steep and shallow acetabulum was excavated and the bipolar socket was placed high with an adjustment of leg-length. At follow-up of between five and seven years, there were 19 excellent, 16 good and five fair results according to the scoring system of Merle d’Aubigné and Postel. The mean radiographic superior migration of the bipolar socket was 2.1 mm (0 to 10). Osteolysis was noted in three hips within three years of the operation. Abduction on weight-bearing was recorded in 24 hips and the bipolar system was found to be functioning predominantly between the inner bearing and the metal femoral head in 20.
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Taira H, Fujikawa Y, Kudo O, Itonaga I, Torisu T. Menatetrenone (vitamin K2) acts directly on circulating human osteoclast precursors. Calcif Tissue Int 2003; 73:78-85. [PMID: 14506958 DOI: 10.1007/s00223-002-2061-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is still not certain what the direct effect of menatetrenone is on osteoclast precursors. In the present study, we investigated whether menatetrenone has a direct effect on circulating osteoclast precursors to influence osteoclast differentiation. Monocytes isolated from human peripheral blood were cultured with receptor-activated NF-kappaB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Menatetrenone or vitamin K1 was then added to the cultures. Geranylgeraniol or phytol (the respective side chain) was also added to the cultures instead of menatetrenone or vitamin K1, respectively. After 7 and 14 days incubation, cultures were evaluated for cytochemical and functional evidence of osteoclast formation. The number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) and the percentage area of lacunar resorption induced by RANKL and M-CSF were decreased when menatetrenone or geranylgeraniol was added to the cultures. Dose-dependent inhibition of osteoclast formation and lacunar resorption was seen when the cultures were treated with menatetrenone or geranylgeraniol. In contrast, vitamin K1 or phytol did not affect the number of TRAP-positive MNCs nor the percentage area of lacunar resorption. These results indicate that menatetrenone not only influences osteoclast formation via bone stromal cells but also acts directly on circulating osteoclast precursors to influence osteoclast differentiation. These findings also suggest that geranylgeraniol, the side chain of menatetrenone, plays an important role in this inhibitory effect.
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Torisu T, Suenaga H, Yoshimatsu T, Kanaoka R, Yamabe Y, Fujii H. Anticipatory and reflexive neck muscle activities during voluntary rapid jaw opening and passive jaw depression in humans. J Oral Rehabil 2002; 29:961-8. [PMID: 12421327 DOI: 10.1046/j.1365-2842.2002.00930.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The characteristics of head movement during voluntary rapid jaw opening movement and passive jaw depression were investigated using accelerometers and electromyographs (EMG) on eight healthy examinees. Passive depressions were executed by means of load on the lower jaw, initiated either by examinees themselves or an experimenter. In the depression initiated by examinees, a head-extension movement that preceded the load to the lower jaw and anticipatory activities in the nuchal region of the trapezius muscle were observed. In the depression initiated by the experimenter, the anticipatory activities were not observed. In both of these cases, stretch reflexes were induced in the trapezius muscle. During voluntary rapid jaw opening, a head-extension movement nearly synchronized with the opening movement in the lower jaw acceleration, and dorsal-neck muscle activities accompanying the synchronized movement were observed. The peak timing of these neck-muscle activities preceded the latencies of the stretch-reflex activities observed in the jaw-depressed tasks, but no anticipatory activities were observed in the dorsal-neck muscles. We conclude that neither the anticipatory activities nor the reflex activities observed in the passive depressions have effects on the initial part of the dorsal-neck muscle activities, which are related to the head-extension synchronized with the voluntary lower-jaw opening movement.
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Iesaka K, Tsumura H, Sonoda H, Sawatari T, Takasita M, Torisu T. The effects of tibial component inclination on bone stress after unicompartmental knee arthroplasty. J Biomech 2002; 35:969-74. [PMID: 12052399 DOI: 10.1016/s0021-9290(01)00244-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Unlike the case with total knee arthroplasty, the femorotibial angle (FTA) after unicompartmental knee arthroplasty (UKA) does not directly depend on the inclination of the tibial component when the height of the joint line is maintained. This study analyzed the effects of the inclination of the tibial component in the coronal plane on the contact pressure of the implant-bone surface and the stresses on the proximal tibia. A two-dimensional, coronal plane model of the proximal tibia was subjected to finite-element analysis. Sixteen patterns of finite-element models of equal FTA were developed in which the inclination of tibial components ranged from 5 degrees valgus to 10 degrees varus in increments of 1 degrees. Stress concentration at the proximal medial diaphyseal cortex gradually increased as the inclination changed from valgus to varus. Maximum contact pressure on the metal-bone interface similarly changed and shifted from the lateral edge to the medial edge of the implant as the inclination changed to varus. It was found that even without changing FTA, the inclination of the tibial component might affect stress concentration and contact pressure in the proximal tibia after UKA. The results suggested that slight valgus inclination of the tibial component might be preferable to varus and even to 0 degrees (square) inclination so far as the stress distribution is concerned.
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Kataoka M, Torisu T, Tsumura H, Yoshida S, Takashita M. An assessment of histopathological criteria for infection in joint arthroplasty in rheumatoid synovium. Clin Rheumatol 2002; 21:159-63. [PMID: 12086168 DOI: 10.1007/s10067-002-8275-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Intraoperative frozen section is reported to be a reliable means of identifying occult infection for preoperative evaluation of arthroplasty. The aim of this study was to determine whether the reported histopathological criteria--the existence of more than 10 polymorphonuclear cells (PMN) per high-power field--is valuable for determination of infection during the arthroplasty of patients with rheumatoid arthritis (RA). The permanent histological sections of RA synovium were analysed to study the degree of infiltration of PMNs. Furthermore, in order to examine the penetrative distribution of PMNs within the synovial tissues, immunohistochemical staining of PMNs was performed. In addition, the clinical history, from the postoperative period to the present, was investigated in 46 patients (60 joints). The presence of early- and/or late-stage postoperative infection, the development of postoperative fever, the progression of erythrocyte sedimentation rate (ESR) (more than 30 mm per hour) and the changes in CRP (more than 10 mg per litre) were further examined and compared with the histopathological tissue analyses and findings. The results demonstrated the presence of more than five PMNs per high-power field, excluding surface fibrin and inflammatory exudate in at least five separate microscopic fields in 10 joints (16.7%) of nine patients, out of 60 joints of 46 patients, in which no postoperative infection was evident. As to the magnitude of penetrative distribution of PMNs in 10 joints, there was a trend of deepening infiltration among the patients with intensive PMN infiltration. In addition, no development of postoperative fever, CRP or continuous indications of high ESR values were evident in this group. As the existence of more than 10 PMN per high-power field was not absolutely indicative of occult infection, investigation of frozen section during arthroplasty should be carefully managed.
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Kudo O, Fujikawa Y, Hirayama T, Torisu T. Osteoclast differentiation factor induces synovial macrophageosteoclast differentiation in rheumatoid arthritis. Mod Rheumatol 2001. [DOI: 10.1007/s10165-001-8062-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Torisu T, Yamabe Y, Hashimoto N, Yoshimatsu T, Fujii H. Head movement properties during voluntary rapid jaw movement in humans. J Oral Rehabil 2001; 28:1144-52. [PMID: 11874515 DOI: 10.1046/j.1365-2842.2001.00782.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of this study was to determine whether the start of the synchronized head movement during mandibular movement is evoked by the peripheral reflexes following mandibular movement (i.e. stretch or trigemino-neck reflexes), or, alternatively, is started by pre-programmed central command. Head movement accompanying voluntary rapid jaw opening movement was studied using accelerometers fixed to the upper and lower incisors, as well as electromyographs (EMGs) of the neck muscles. The direction of head acceleration at the upper incisor was towards head extension at the beginning of jaw opening movement in 89.2% of all trials, opposite to the direction of lower jaw acceleration. The onset of head acceleration was later than that of the lower jaw acceleration by averages of 6.2-10.7 ms, and the onset of electromyographic activities of the sternocleidomastoid (SCM) muscle preceded that of head acceleration by an average of 12.5-24.3 ms. These findings suggest that head movement during mandibular movement is not started by peripheral reflexes but by pre-programmed central commands. This may be relevant to muscular discomfort in the neck and shoulder regions of patients with stomatognathic disorders.
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Torisu T. [How to modify the Japanese translation for rheumatoid arthritis]. RYUMACHI. [RHEUMATISM] 2001; 41:849-50. [PMID: 11729662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Hirayama T, Fujikawa Y, Itonaga I, Torisu T. Effect of particle size on macrophage-osteoclast differentiation in vitro. J Orthop Sci 2001; 6:53-8. [PMID: 11289587 DOI: 10.1007/s007760170025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To determine whether particle size affects macrophage-osteoclast differentiation in vitro, latex beads of 0.1, 1, and 10 microm in diameter were added to a murine macrophage-UMR106 osteoblast-like cell coculture system. The extent of osteoclast differentiation was determined by assessing the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells on glass coverslips and the extent of lacunar resorption on dentine slices. The addition of particles, 1 and 10microm in size, to the cocultures resulted in a significant increase in the number of TRAP-positive osteoclast-like cells and in the resorption pit surface area compared with findings in control cultures to which no particles had been added. Particles 0.1 microm in size also stimulated osteoclast formation relative to the control; however, the difference was not significant. These results indicate that particles, particularly these 1 and 10microm in size, sizes which were phagocytosable, significantly enhanced the process of macrophage-osteoclast differentiation and suggest that particle size plays an important role in periprosthetic osteolysis.
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Suenaga H, Torisu T, Yoshimatsu T, Fujii H. Influence on force curve exerted by jaw tapping force. J Oral Rehabil 2001; 28:673-7. [PMID: 11422701 DOI: 10.1046/j.1365-2842.2001.00698.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of this study, which made use of visual biofeedback, was to determine how methods of regulating jaw tapping force differed depending on the strength of the tapping, using the force curve as an index. Nine healthy examinees were asked to make 30-35 jaw tapping movements, reproducing the defined target tapping force as accurately as possible. We measured the duration of the tooth contact phase, the time to peak force, the first time derivative of force (peak dF/dt), and the time to peak dF/dt. The results indicated that the duration of the tooth contact phase and the time to peak force increased with the target value (P < 0.01). As the target rose, the peak dF/dt increased significantly (P < 0.01), but the time to peak dF/dt was not significant (P=0.134). We found that the higher the target value, the greater the degree of dependency on feedback information. We also found that both the peak dF/dt and the time to peak dF/dt were determined for each examinee prior to movement.
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