Yoshiki Hamada

Tsurumi University, Yokohama, Kanagawa, Japan

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Publications (124)147.67 Total impact

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    ABSTRACT: Metal often causes delayed-type hypersensitivity reactions, which are possibly mediated by accumulating T cells in the inflamed skin, called irritant or allergic contact dermatitis. However, accumulating T cells during development of a metal allergy are poorly characterized because a suitable animal model is unavailable. We have previously established novel murine models of metal allergy and found accumulation of both metal-specific T cells and natural killer (NK) T cells in the inflamed skin. In our novel models of metal allergy, skin hypersensitivity responses were induced through repeated sensitizations by administration of metal chloride and lipopolysaccharide into the mouse groin followed by metal chloride challenge in the footpad. These models enabled us to investigate the precise mechanisms of the immune responses of metal allergy in the inflamed skin. In this review, we summarize the immune responses in several murine models of metal allergy and describe which antigen-specific responses occur in the inflamed skin during allergic contact dermatitis in terms of the T cell receptor. In addition, we consider the immune regulation of accumulated NK T cells in metal ion-induced allergic contact dermatitis.
    Preview · Article · Jan 2016 · International Journal of Molecular Sciences
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    ABSTRACT: Iliac particulate cancellous bone and marrow (PCBM) is still the most predictable autogenous graft material for vertical ridge reconstruction because of its high cell content as well as osteoinductive and osteoconductive properties. However, postoperative meralgia paresthetica, gait disturbance, pain, and bleeding have been reported following conventional harvesting from the anterior iliac crest. We present a case of minimally invasive harvesting of iliac PCBM. A short incision was made, and the iliac crest was exposed after elevation of the periosteal membrane. Only the iliac cortical bone was removed using a trephine bur to avoid perforation. PCBM was harvested with hand curettes and grafted into the vertical ridge defect. Because of the small surgical field, gait disturbance was resolved within 1 day without other postoperative complications. This technique is potentially useful for harvesting a small amount of iliac PCBM.
    Full-text · Article · Dec 2015
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    ABSTRACT: Poly(ADP-ribosyl)ation is known to be involved in a variety of cellular processes, such as DNA repair, cell death, telomere regulation, genomic stability and cell differentiation by poly(ADP-ribose) polymerase (PARP). While PARP inhibitors are presently under clinical investigation for cancer therapy, little is known about their side effects. However, PARP involvement in mesenchymal stem cell (MSC) differentiation potentiates MSC-related side effects arising from PARP inhibition. In this study, effects of PARP inhibitors on MSCs were examined. MSCs demonstrated suppressed osteogenic differentiation after 1 µM PJ34 treatment without cytotoxicity, while differentiation of MSCs into chondrocytes or adipocytes was unaffected. PJ34 suppressed mRNA induction of osteogenic markers, such as Runx2, Osterix, Bone Morphogenetic Protein-2, Osteocalcin, bone sialoprotein, and Osteopontin, and protein levels of Bone Morphogenetic Protein-2, Osterix and Osteocalcin. PJ34 treatment also inhibited transcription factor regulators such as Smad1, Smad4, Smad5 and Smad8. Extracellular mineralized matrix formation was also diminished. These results strongly suggest that PARP inhibitors are capable of suppressing osteogenic differentiation and poly(ADP-ribosyl)ation may play a physiological role in this process through regulation of BMP-2 signaling. Therefore, PARP inhibition may potentially attenuate osteogenic metabolism, implicating cautious use of PARP inhibitors for cancer treatments and monitoring of patient bone metabolism levels.
    Full-text · Article · Oct 2015 · International Journal of Molecular Sciences

  • No preview · Article · Oct 2015 · International Journal of Oral and Maxillofacial Surgery
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    ABSTRACT: Background: Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and novel effective treatments and diagnostic tools are urgently required. Objective: The selection of appropriate targeting tumor-associated antigens (TAAs) is critical for immunotherapy. Therefore, we analyzed TAA expression levels and investigated their relationship with clinical factors in adjacent normal mucosa (ANM) and CRC tissue. Methods: We obtained specimens of CRC primary tumors and matched ANM from 137 patients with CRC who underwent surgical resection. The mRNA levels of seven TAAs, Wilms' tumor gene (WT1), kinetochore associated-2 (KNTC2), cell division cycle associated-1 (CDCA1), M phase phosphoprotein-1 (MPHOSPH1), DEP domain-containing 1 (DEPDC1), 34-kDa translocase of the outer mitochondrial membrane (TOMM34) and ring finger protein-43 (RNF43), were analyzed using quantitative real-time reverse transcription-polymerase chain reaction, and their relationships with clinicopathological factors and the cell cycle were analyzed. Results: The expression levels of all seven TAAs were significantly higher in CRC tissues than in ANM. Expression levels of WT1 in CRC tissues did not correlate with the cell cycle. Furthermore, WT1 expression in CRC tissues was significantly related to tumor progression, lymph node metastasis, distant metastasis and clinical stage. Conclusions: WT1 is a potential marker for prognosis and tumor progression in CRC.
    Full-text · Article · Sep 2015 · Cancer biomarkers: section A of Disease markers
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    ABSTRACT: Objectives: The surgical target of Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is the masseter or temporal muscle. In our clinic, the 4-dimentional muscle model (4DMM) has been used to decide if we should approach to the masseter or temporal muscle. The aim of this study is validate the clinical usefulness of 4DMM on the basis of the surgical results. Methods: The 4DMM was constructed from the digital data of 3D-CT and 4-dimentional mandibular movements of the patients. It made us to able to visually observe the expansion rate of masticatory muscles at maximum mouth opening comparing to their length at closed mouth position. Fifteen patients were applied the 4DMM before the surgical treatment and 2 healthy volunteers were enrolled as control group. Results: The expansion rate of temporal muscle at the maximum mouth opening in the patient group was significantly less than that in the control group (P < 0.05). On the other hand, the masseter muscles of all patients were expanded as same as the control group. Therefore the main cause of limitation of mouth-opening was suggested to be a contracture of the temporal muscle. Consequently, we performed successful bilateral coronoidectomy with no surgical intervention to the masseter muscles in all patients. Conclusion: The present 4DMM would be valuable modality to decide the target muscle of surgical treatment for patients with MMTAH. In this pathology, contracture of the temporal muscle seems to be main cause of limited mouth opening.This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/4.0.
    Full-text · Article · Sep 2015 · The Journal of craniofacial surgery
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    ABSTRACT: Temporomandibular joint (TMJ) osteoarthritis is typically a slowly progressive asymmetric disease. Little is known regarding the natural destruction of TMJ articular tissues. The aim of the present study was to investigate morphological changes in the TMJ of STR/ort mice, known to be the model for spontaneous osteoarthritis in the knee joint, and to evaluate STR/ort mice as a suitable animal model for TMJ osteoarthritis. TMJs from 32 STR/ort mice euthanized at 30, 40, 50 or 60 weeks of age, and from 6 CBA mice euthanized at 30, 40 or 60 weeks of age were examined. Toluidine blue and tartrate-resistant acid phosphatase staining were used to assess histological changes in the articular cartilage. Morphological changes in the articular cartilage of the TMJ were evaluated using microcomputed tomography. At the age of 40-50 weeks, 17 (68%) of the 25 STR/ort mice had loss of articular cartilage on histology, with cavitation and erosion of the exposed bone and gradual changes in condylar shape. Furthermore, osteoarthritic morphological changes, and structural alterations were observed by microcomputed tomography. The STR/ort mouse strain appears to develop spontaneous osteoarthritis-like lesions in the TMJ with age, and would be a useful model to study the pathogenesis of TMJ osteoarthritis.
    Full-text · Article · May 2015
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    ABSTRACT: This case report describes the orthodontic treatment performed for open bite caused by internal derangement (ID) and osteoarthritis (OA) of the temporomandibular joint (TMJ). A Japanese woman, aged 31 years and 11 months, referred to our department by an oral surgeon had an open bite with clockwise rotation of the mandible and degeneration of the condyle. The overbite was corrected through intrusion of the maxillary and mandibular molars using mini-screw implants to induce counterclockwise rotation of the mandible. Then, the mandibular second premolars were extracted and comprehensive orthodontic treatment was performed to establish a Class I molar relationship with distalization of the maxillary arch and to eliminate anterior crowding. Following treatment, her facial profile improved and a functional and stable occlusion was achieved without recurrence of the TMJ symptoms. These results suggest that orthodontic intrusion of the molars is one of the safer and less stressful alternatives for the management of open bite due to degeneration of the condyles caused by ID and OA of TMJ.
    Preview · Article · May 2015 · Korean Journal of Orthodontics
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    ABSTRACT: Objective: To clarify whether the concept of main occluding area, where hard food is initially crushed, exists in patients who have a jaw deformity. Materials and methods: Nineteen subjects with normal occlusion, 18 patients with mandibular prognathism, and 11 patients with mandibular prognathism who had undergone orthognathic surgery participated in this study. The main occluding area was identified by clenching Temporary Stopping. The coincidence, location of the main occluding area, and distance from the first molars to main occluding area were examined. Results: High coincidence of the main occluding area was obtained in all groups, signifying that the main occluding area exists even in these patients. Mandibular main occluding area was located on the first molar in all groups. Maxillary main occluding area in subjects with normal occlusion was located on the first molar. However, it was located on the second premolar and first molar in patients with mandibular prognathism, and on the first and second molars in patients with mandibular prognathism who had undergone orthognathic surgery. There was a statistically significant difference in distance from the maxillary first molar to the main occluding area among groups, but there was no difference in the distance from the mandibular first molar among groups. Conclusion: The main occluding area is more stable on the mandibular first molar than the maxilla in all groups.
    No preview · Article · Apr 2015 · The Angle Orthodontist
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    Preview · Article · Jan 2015 · Nippon Koku Geka Gakkai zasshi
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    ABSTRACT: Central odontogenic fibroma (COF) is a rare odontogenic tumor, the primary treatment of which is tumor ablation with extraction of related teeth. We report a case of COF that developed in the left maxilla in a 24-year-old woman. There were no subjective symptoms, however, she had noticed malposition of the second premolar to the palatal side and slight swelling of the buccal gingiva around the tooth since nine years old. The swelling had recently become larger, and she was referred to our clinic. A biopsy of the lesion showed a histological diagnosis of COF. CT images revealed resorption of the alveolar bone around the tumor, and expansion to the roots of the premolars and first molar. Reconstruction of the alveolar ridge using iliac particulate cancellous bone and marrow was carried out immediately after tumor ablation with extraction of the premolars and first molar. Five months later, there was no evidence suggesting tumor recurrence, and alveolar ridge augmentation was clearly apparent on CT images. The serial dental implant treatment was thus completed. The occlusion was restored by an implant prosthesis, and no evidence of tumor recurrence was found during four years of follow-up.
    No preview · Article · Jan 2015

  • No preview · Article · Jan 2015 · Nippon Koku Geka Gakkai zasshi

  • No preview · Article · Sep 2014 · Journal of Oral and Maxillofacial Surgery
  • K. Kawaguchi · T. Amemiya · H. Shimizu · Y. Hamada
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    ABSTRACT: The use of stereotactic body radiation therapy is rapidly increasing among patients with lung cancer not amenable to surgery. The authors report their experience using the CyberKnife system (Accuray Inc., Sunnyvale, CA, USA) as a treatment option for synchronous cancer of oral squamous cell carcinoma and a malignant lung tumour. An 88-year-old woman with two cancers (oral and lung masses) underwent CyberKnife treatment, with fiducial gold pins implanted using bronchoscopy. Toxicity was limited, and at the 2-year follow-up the lesions had not recurred.
    No preview · Article · Jun 2014 · International Journal of Oral and Maxillofacial Surgery
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    ABSTRACT: Intramuscular hemangioma (IMH) is relatively rare benign tumor of vascular origin. Phleboliths are calcified thrombi found in the presence of hemangioma. The main treatment of the hemangioma is a surgical extirpation based on location, accessibility, and cosmetic considerations. We herein report a rare case of IMH with phleboliths of the tongue with clinical, imaging, and histopathological findings.
    No preview · Article · Apr 2014
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    ABSTRACT: In the present study, tissue responses of two types of three-dimensional titanium fiber structure, namely, titanium web (TWe) and titanium wire (TWi), were evaluated for external and internal bone augmentation, respectively. TWe was produced by sintering intertwined thin titanium fibers. TWi was produced by interweaving thin titanium fibers without a sintering process. The mechanical strength was superior in TWe and the formability was superior in TWi. As surface modifications of TWe and TWi, both CA coating using a molecular precursor method and immobilization of cell-adhesive protein, collagen and fibronectin, using the tresyl chloride-activated method were employed. TWe materials were implanted under the periosteum of rat calvaria to evaluate the external bone augmentation. TWi materials were implanted into the bone defect of rabbit femoral condyle to evaluate the internal bone augmentation. After 4 and 8 weeks for rat experiments with TWe materials and 12 weeks for rabbit experiments with TWi materials, new bone formation inside the porous area of the fiber structure was histologically evaluated. The bone formation rate (BFR) and the vertical bone augmentation rate (VBR) were also histomorphometrically analyzed. BFR and VBR of CA-coated TWe and TWi were significantly higher than those of non-coated TWe and TWi, respectively, for rat external and rabbit internal bone augmentation (p<0.05). BFR of collagen- or fibronectin-immobilized TWi was significantly higher than for non-coated TWi for rabbit internal bone augmentation (p<0.05), but not for rat external bone augmentation (p>0.05). In conclusion, it is suggested that surface-modified three-dimensional titanium fiber structure is a good candidate as a three-dimensional scaffold for regenerative medicine. © 2014 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.
    No preview · Article · Apr 2014 · Journal of Hard Tissue Biology
  • Go Tsumuraya · Hiroyuki Yamada · Hajime Shimizu · Yoshiki Hamada
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    ABSTRACT: This is the first report to our knowledge of an intramuscular lipoma that arose in the masseter muscle. Excision biopsy under general anaesthesia showed that the mass could easily be separated from the surrounding soft tissues on the lateral side, but was firmly adherent to the muscle on the medial side, so complete excision required resection of part of the masseter. Histopathological examination showed that it was an intramuscular lipoma. Two years and 6 months postoperatively there was no evidence of recurrence.
    No preview · Article · Apr 2014 · British Journal of Oral and Maxillofacial Surgery
  • Keisuke Fujii · Kenichi Kumagai · Yoshiki Hamada · Ryuji Suzuki
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    ABSTRACT: Objective This study investigated the expression of CD44 and CD133, the two surface markers most commonly used to identify cancer stem cells (CSCs), as predictive markers for clinicopathological progression and lymph node metastasis in oral squamous cell carcinoma (OSCC). Methods OSCC primary tumor specimens obtained from 29 patients with OSCC who underwent resection as well as the normal oral mucosa samples of 14 healthy volunteers were enrolled in this study. We studied expression of CD133 and CD44 using real-time RT-PCR, immunohistochemistry and western blot analysis in primary OSCC, and investigated the correlation of clinicopathological factors. Results Although CD133 protein expression was not obviously detected, CD133 mRNA expression in primary OSCC tissues significantly correlated with lymph node metastasis, depth of invasion, extranodal invasion, and clinical stage. Conclusions CD133 mRNA over-expression in OSCC primary tumors could be a novel independent prognostic marker that correlates with tumor progression and lymph node metastasis.
    No preview · Article · Apr 2014
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    ABSTRACT: Myofibroma is a benign tumor composed of myoid spindle cells. The prevalence of myofibroma in the oral cavity is very low, with the mandible being the most common site. This report describes an adult case of myofibroma that arose on the mandible and includes magnetic resonance imaging (MRI) and positron emission tomography (PET) findings. On the MRI T1-weighted images, the tumor appeared with signal iso-intensity and was highly and heterogeneously enhanced with contrast material. On the T2-weighted images, it appeared with increased signal intensity. 18 F-fluorodeoxyglucose (FDG)-PET imaging showed abnormal strong accumulation of FDG in the left mandibular region. The tumor was removed by marginal resection of the left mandible under general anesthesia. Histopathological findings revealed that the tumor stroma contained abundant thin-walled vessels. The postoperative course was uneventful, and we found no evidence of recurrence at the postoperative 34-month follow-up.
    Full-text · Article · Mar 2014 · World Journal of Surgical Oncology
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    ABSTRACT: Chromium (Cr) causes delayed-type hypersensitivity reactions possibly mediated by accumulating T cells into allergic inflamed skin, which are called irritants or allergic contact dermatitis. However, accumulating T cells during development of metal allergy are poorly characterized because a suitable animal model is not available. This study aimed to elucidate the skewing of T-cell receptor (TCR) repertoire and cytokine profiles in accumulated T cells in inflamed skin during elucidation of Cr allergy. A novel model of Cr allergy was induced by two sensitizations of Cr plus lipopolysaccharide solution into mouse groin followed by single Cr challenge into the footpad. TCR repertoires and nucleotide sequences of complementary determining region 3 were assessed in accumulated T cells from inflamed skin. Cytokine expression profiles and T-cell phenotypes were determined by qPCR. CD3+CD4+ T cells accumulated in allergic footpads and produced increased T helper 1 (Th1) type cytokines, Fas, and Fas ligand in the footpads after challenge, suggesting CD4+ Th1 cells locally expanded in response to Cr. Accumulated T cells included natural killer (NK) T cells and Cr-specific T cells with VA11-1/VB14-1 usage, suggesting metal-specific T cells driven by invariant NKT cells might contribute to the pathogenesis of Cr allergy.
    Full-text · Article · Jan 2014 · PLoS ONE