研究者データベース

八若 保孝(ヤワカ ヤスタカ)
歯学研究院 口腔医学部門 口腔機能学分野
教授

基本情報

所属

  • 歯学研究院 口腔医学部門 口腔機能学分野

職名

  • 教授

学位

  • 博士(歯学)(北海道大学)

J-Global ID

研究キーワード

  • 小児歯科学   歯根吸収に関する組織学   Pediatric Dentistry   Histology of root resorption   

研究分野

  • ライフサイエンス / 成長、発育系歯学
  • ライフサイエンス / 常態系口腔科学

職歴

  • 2003年04月 - 2005年03月 北海道大学病院歯科診療センター 咬合B(小児歯科専門)外来 講師
  • 2000年04月 - 2003年03月 北海道大学大学院歯学研究科 口腔機能学講座小児歯科学分野 助手
  • 1993年06月 - 2000年03月 北海度大学歯学部 小児歯科学講座 助手
  • 1990年01月 - 1993年05月 北海道大学歯学部附属病院 小児歯科 助手
  • 1986年 - 1989年 北海道大学歯学部附属病院医員(小児歯科) 職員(医療系)
  • 1986年 - 1989年 Medical Staff

所属学協会

  • 日本接着歯学会   アジア外傷歯学会   日本歯科医学教育学会   日本外傷歯学会   日本小児歯科学会   国際歯科研究学会(International Association for Dental Research)   北海道歯学会   歯科基礎医学会   成育歯科医療研究会   Asian International Association of Dental Traumatology   International Association for Dental Research   

研究活動情報

書籍

  • 小児歯科学 第4版
    医歯薬出版株式会社 2011年
  • 治療4月増刊号 デキる医師の紹介・逆紹介スキル99
    南山堂 2010年
  • スペシャルニーズデンティストリー障害者歯科
    医歯薬出版株式会社 2009年
  • 日本歯科医学教育学会 歯科医学教育白書作成委員会(編),日本歯科医学教育学会雑誌別冊 歯科医学教育白書2005年度版(2003~2005年)
    日本歯科医学教育学会(財:口腔保健協会) 2006年
  • 乳歯列期における外傷歯の診断と治療<木村光孝,高木裕三,香西克之,朝田芳信(編)>
    クインテッセンス出版 2005年
  • 乳歯列期における外傷歯の診断と治療<木村光孝,高木裕三,香西克之,朝田芳信(編)>
    クインテッセンス出版 2005年
  • 乳歯列期における外傷歯の診断と治療<木村光孝,高木裕三,香西克之,朝田芳信(編)>
    クインテッセンス出版 2005年

その他活動・業績

  • Koichi Nakamura, Yoshiaki Deyama, Yoshitaka Yoshimura, Masanor Hashimoto, Masayuki Kaga, Kuniaki Suzuki, Yasutaka Yawaka MOLECULAR MEDICINE REPORTS 4 (4) 641 -644 2011年07月 [査読無し][通常論文]
     
    Glass ionomer cements (GICs) are widely used for the operative restoration of dental caries. However, it has been reported that the components of GICs cause pulpal inflammatory responses. Recently, GICs containing tannin-fluoride preparation (HY agent) were developed. In this study, we investigated the effect of HY agent on prostaglandin E, (PGE(2)) release from GIC-stimulated rat dental pulp cells (RPC-C2A). Extracts derived from GIC disks were used with HY(+) and without HY(-) agent. After treatment with GIC extracts, ATP contents, COX-2 mRNA and protein expression in RPC-C2A cells, and PGE(2) production in culture media were analyzed. HY agent suppressed HY(-)-stimulated PGE(2) release from RPC-C2A cells, as well as COX-2 mRNA and protein expression. Moreover, tannic acid attenuated COX-2 mRNA induced by HY(-) extract in a dose-dependent manner. Taken together, these results suggest that tannic acid in MY agent may suppress GIC-induced production of PGE(2) by inhibition of COX-2 expression in dental pulp cells.
  • Hajime Minamikawa, Masahiro Yamada, Yoshiaki Deyama, Kuniaki Suzuki, Masayuki Kaga, Yasutaka Yawaka, Takahiro Ogawa JOURNAL OF ENDODONTICS 37 (5) 637 -641 2011年05月 [査読無し][通常論文]
     
    Introduction: The purpose of this study was to evaluate the cytotoxicity of mineral trioxide aggregate (MTA) and its potential detoxification by an antioxidant amino acid, N-acetylcysteine (NAC). Methods: Rat dental pulp cells extracted from rat maxillary incisors were directly cultured on MTA with or without NAC in culture medium. The number of cells and their spreading behavior were both assessed 24 hours after seeding. The intracellular levels of reactive oxygen species (ROS) and glutathione (GSH) were also assessed after 24 hours of culture. Results: The number of cells attached to MTA was 60% greater when NAC was added to the culture medium. In addition, the area and perimeter of the cells were found to be 2-fold greater in the culture containing NAC. Cells cultured on MTA alone showed large ROS concentrations, which disappeared when the medium was supplemented with NAC. The intracellular GSH level, however, increased 3.5-fold with NAC addition. Conclusion's: This study demonstrated that the presence of NAC in environments can substantially improve attachment and spreading behaviors of dental pulp cells on MTA. This biological effect was associated with an im-provement in the cellular redox system by NAC and warrants further exploration of NAC for determining its therapeutic value in improving the biocompatibility of MTA. (J Endod 2011;37:637-641)
  • 小児歯科学雑誌 49 (5) 465 -473 2011年 [査読無し][通常論文]
  • Nano Biomedicine 3 (1) 191 -199 2011年 [査読無し][通常論文]
  • The Japanese Journal of Pediatric Dentistry 49 (5) 465 -473 2011年 [査読無し][通常論文]
  • Shohei Oshima, Junichi Suzuki, Yasutaka Yawaka Pediatric Dental Journal 20 (1) 91 -94 2010年 [査読無し][通常論文]
     
    Idiopathic osteosclerosis (IO) is a localized, well-defined, intra-bony radiopaque lesion within cancellous bone. The causes of IO are still unknown and most lesions are nonexpansile and asymptomatic, so they are often detected incidentally on radiographic examination for other purposes. In the case of jaw lesions, IO is considered to be of no clinical significance and usually requires no treatment. This paper describes two clinical cases about the long-term treatments and observations of mandibular IO in adolescents. The lesions were associated with abnormal tooth root formation and tooth malposition. In these cases, the orthodontic treatments finished successfully without any complication despite the lesions. IO in the jaw needs regular follow-up to ensure normal orofacial development during adolescence. © 2010, The Japanese Society of Pediatric Dentistry. All rights reserved.
  • 小児歯科学雑誌 48 (1) 56 -63 2010年 [査読無し][通常論文]
  • 小児歯科学雑誌 48 (1) 48 -55 2010年 [査読無し][通常論文]
  • 小児歯科学雑誌 48 (1) 29 -39 2010年 [査読無し][通常論文]
  • 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
    北海道・北海道歯科医師会 2010年 [査読無し][通常論文]
  • The Japanese Journal of Pediatric Dentistry 48 (1) 64 -72 2010年 [査読無し][通常論文]
  • The Japanese Journal of Pediatric Dentistry 48 (1) 56 -63 2010年 [査読無し][通常論文]
  • The Japanese Journal of Pediatric Dentistry 48 (1) 48 -55 2010年 [査読無し][通常論文]
  • The Japanese Journal of Pediatric Dentistry 48 (1) 29 -39 2010年 [査読無し][通常論文]
  • Hajime Minamikawa, Yoshiaki Deyama, Kouichi Nakamura, Yoshitaka Yoshimura, Masayuki Kaga, Kuniaki Suzuki, Yasutaka Yawaka JOURNAL OF ENDODONTICS 35 (6) 843 -846 2009年06月 [査読無し][通常論文]
     
    Introduction: Recently, mineral trioxide aggregate (MTA) has been routinely used for endodontic treatment. It is well-known that MTA induced secondary dentin formation in pulp cavity when it was applied to dentin, whereas its cytotoxicities were unclear. The purpose of this study was to evaluate the effect of MTA on rat clonal dental pulp cells, RPC-C2A. Methods: This study was conducted to observe the response of RPC-C2A cells on MTA with reverse-transcriptase polymerase chain reaction, Western blot analysis, and enzyme immunoassay. Data were compared by analysis of variance. Statistical significance was established at P <.01. Results: MTA significantly caused an up-regulation of cyclooxygenase-2 (COX-2) and inducible form of nitric oxide synthase (iNOS) mRNA expression. Furthermore, MTA caused inhibitory kappa B (I kappa B) phosphorylation and translocation of nuclear factor-kappa B (NF-kappa B) subunits to nucleus. Curucumin, an inhibitor of NF-kappa B activation, suppressed MTA-induced COX-2 and NOS mRNA expressions, In addition, MTA increased the production of prostaglandin E(2) in comparison with the controls. Conclusions: MTA induces inflammation via NF-kappa B signaling system. (J Endod 2009;35:843-846)
  • Mari M. Sato, Masayuki Nashimoto, Takenobu Katagiri, Yasutaka Yawaka, Masato Tamura BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 383 (1) 125 -129 2009年05月 [査読無し][通常論文]
     
    MicroRNAs (miRNAs) are small non-coding RNAs that are emerging as important post-transcriptional gene regulators. miR-206 is unique in that it is expressed only in skeletal muscle, including the myoblastic C2C12 cell line. In C2C12 cells, miR-206 expression was reduced dramatically after bone morphogenetic protein (BMP)-2 treatment. The down-regulation of miR-206 expression was also observed after co-transfection with constitutively-active Smad1 and Smad4, which are the intracellular signaling molecules of the BMP pathway. BMP-2 also reduced miR-206 expression in the presence of alpha-amanitin in a similar manner to that in the absence of alpha-amanitin. Moreover, the expression of pri-miR-206 was increased upon BMP-2 treatment for 6 h compared to that in the absence of BMP-2. These results suggested that BMP-2 down-regulates miR-206 expression at the post-transcriptional level, by inhibiting the processing of pri-miR-206 into mature miR-206, and that BMP-2 Could regulate miRNA biogenesis by a novel mechanism. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.
  • Masaru Nakajima, Masafumi Yamada, Koji Yamaguchi, Yukio Sakiyama, Atsushi Oda, David L. Nelson, Yasutaka Yawaka, Tadashi Ariga EUROPEAN JOURNAL OF HAEMATOLOGY 82 (3) 223 -230 2009年03月 [査読無し][通常論文]
     
    The Wiskott-Aldrich syndrome protein (WASP), which is defective in Wiskott-Aldrich syndrome (WAS) patients, is an intracellular protein expressed in non-erythroid hematopoietic cells. Previously, we have established methods to detect intracellular WASP expression in peripheral blood mononuclear cells (PBMNCs) using flow cytometric analysis (FCM-WASP) and have revealed that WAS patients showed absent or very low level intracellular WASP expression in lymphocytes and monocytes, while a significant amount of WASP was detected in those of normal individuals. We applied these methods for diagnostic screening of WAS patients and WAS carriers, as well as to the evaluation of mixed chimera in WAS patients who had previously undergone hematopoietic stem cell transplantation. During these procedures, we have noticed that lymphocytes from normal control individuals showed dual positive peaks, while their monocytes invariably showed a single sharp WASP-positive peak. To investigate the basis of the dual positive peaks (WASP(low-bright) and WASP(high-bright)), we characterized the constituent linage lymphocytes of these two WASP-positive populations. As a result, we found each WASP(low/high) population comprised different linage PBMNCs. Furthermore, we propose that the difference between the two WASP-positive peaks did not result from any difference in WASP expression in the cells, but rather from a difference in the structural and functional status of the WASP protein in the cells. It has been shown that WASP may exist in two forms; an activated or inactivated form. Thus, the structural and functional WASP status or configuration could be evaluated by flow cytometric analysis.
  • SATO Mari M, NAKASHIMA Aiko, NASHIMOTO Masayuki, YAWAKA Yasutaka, TAMURA Masato Gene to Cells 14 (2) 141 -153 2009年02月 [査読無し][通常論文]
     
    Wnt/beta-catenin signaling plays an important role in the developing skeletal system. Our previous studies demonstrated that Wnt/beta-catenin signaling inhibits the ability of bone morphogenetic protein (BMP)-2 to suppress myotube formation in the multipotent mesenchymal cell line C2C12 and that this inhibition is mediated by Id1. In this study, we examined the role of intracellular signaling by Wnt/beta-catenin and BMP-2 in regulating the expression of osteoprotegerin (OPG) and of the receptor activator of NF kappa B ligand (RANKL). OPG expression was induced by Wnt/beta-catenin signaling in C2C12 cells and osteoblastic MC3T3-E1 cells. Silencing of glycogen synthase kinase-3 beta also increased OPG expression. In contrast, R expression was suppressed by Wnt/beta-catenin signaling. In a transfection assay, beta-catenin induced the activity of a reporter gene, a 1.5 kb fragment of the 5'-flanking region of the OPG gene. Deletion and mutation analysis revealed that Wnt/beta-catenin signaling regulates transcription of OPG via a promoter region containing two Wnt/beta-catenin responsive sites. BMP-2 enhanced Wnt/beta-catenin-dependent transcriptional activation of the OPG promoter. In response to BMP-2 stimulation, Smad 1 and 4 interacted with Wnt/beta-catenin responsive sites. These results show that the regulation of OPG expression is mediated through two transcription pathways that involve the OPG promoter.
  • 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
    北海道・北海道歯科医師会 2009年 [査読無し][通常論文]
  • Masanori Hashimoto, Shinichi Fujita, Masayuki Kaga, Yasutaka Yawaka DENTAL MATERIALS JOURNAL 27 (2) 172 -178 2008年03月 [査読無し][通常論文]
     
    This study evaluated the effect of water on dentin substrate bonding of one-bottle self-etching adhesives. Dentin substrates were divided into two groups: wet and dry dentin. Wet dentin is the normal substrate for bond testing whereas dry dentin was dehydrated in a desiccator for 24 hours. Bonded dehydrated teeth were then divided into two subgroups: stored in water or in desiccator for 24 hours. Microtensile bond strength of resin to dentin was measured using three one-bottle self-etching adhesives. In addition, nanoleakage evaluation was performed through the analyses of SEM and TEM micrographs. The bond strength of dry-dentin group was significantly greater than that of wet-dentin. Further, the amount of nanoleakage within the adhesive interface of dry-dentin group was less than that of wet-dentin. Results showed that bond strength and nanoleakage formation depended on the bonding substrate (wet versus dry dentin) before bonding. One-bottle self-etching adhesives might suck the water from dentinal tubules (luring bonding by osmosis, leading to nanoleakage formation and thus a decline in bond strength.
  • Pediatric Dental Journal 18 (2) 210 -213 2008年 [査読無し][通常論文]
  • 外傷歯への処置に関する新しい知見
    北海道歯学雑誌 29 (1) 108 -111 2008年 [査読無し][通常論文]
  • ラットにおける亜鉛過剰摂取による銅吸収阻害機構
    北海道歯学雑誌 29 (1) 89 -98 2008年 [査読無し][通常論文]
  • Toshihiro Yoshihara, Yasutaka Yawaka PHYSIOLOGY & BEHAVIOR 93 (1-2) 322 -326 2008年01月 [査読無し][通常論文]
     
    Repeated inunobilization stress tests in the early postnatal period were performed to determine the effects on the growth of developing rats as well as the response of the HPA axis to subsequent novel stress in adulthood. In addition, effects of maternal deprivation (MD) with the same period of the exposure to immobilization stress were also examined. We used 2 different types of immobilization stress and 2 different types of MD: immobilization stress for 30 min/day from postnatal day 7 (P7) to P13 (IS7-13 group); immobilization stress for 30 min on P7 (IS7 group); MD for 30 min/day from P7 to P13 (MD7-13 group); and MD for 30 min on P7 (MD7 group). Body weights were lower in the IS7-13 group than in the control group from P10 to P50, although body weight gain in the MD7-13 group was only transiently affected. Stress-induced corticosterone levels in the IS7-13 group were higher than in the control group and did not return to baseline levels until at least 120 min after the termination of stress, whereas temporal variations of stress-induced corticosterone levels did not differ between the IS, MD7-13, MD7, and control groups. Repeated immobilization stress in the early postnatal period induced long-tern effects on the growth of developing rats and stress response of the HPA axis to the novel stress in adulthood, although a single immobilization stress, periodic MD, or a single MD had little effect. (C) 2007 Elsevier Inc. All rights reserved.
  • 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
    北海道・北海道歯科医師会 2008年 [査読無し][通常論文]
  • Masanori Hashimoto, Shinichi Fujita, Masayuki Kaga, Yasutaka Yawaka DENTAL MATERIALS JOURNAL 26 (5) 677 -686 2007年09月 [査読無し][通常論文]
     
    Recently, one-bottle resins adhesives have been developed to reduce the number of clinical steps of resin application. They are now widely used in clinical dental practice. However, little is known regarding the detailed mechanism of bond degradation. Therefore, this study evaluated the durability of one-bottle resin adhesives using long-term water storage testing. Resin-dentin bonded specimens were prepared using five commercially available one-bottle resin adhesives. The specimens were sectioned perpendicular to the adhesive interface to produce beams and stored in distilled water for 24 hours (control), 100, 200, and 300 days. After the water storage, each beam was subjected to a microtensile bond test and then SEM fractography was performed on the fractured surface. Compared to the bond strength at 24 hours after bonding (control), the bond strength of all tested adhesives were significantly decreased after 100 or more days in water. SEM fractography revealed a typical type of deterioration in the adhesive-composite interface that might cause a decline in bond strength after aging.
  • 八若保孝, 岩渕英明, 伊藤佐智子, 加我正行 小児歯科学雑誌 45 (5) 623 -631 2007年 [査読無し][通常論文]
  • 加我正行, 岩渕英明, 中村光一, 橋本正則, 八若保孝 小児歯科学雑誌 45 (1) 81 -87 2007年 [査読無し][通常論文]
  • Flow cytometryを用いた末梢血単核球によるWASの構造的・機能的解析に関する研究
    北海道歯学雑誌 27 (2) 190 -200 2006年 [査読無し][通常論文]
  • ヒト乳歯の生理的歯根吸収下における破歯細胞のアポトーシスに関する免疫組織学的研究
    北海道歯学雑誌 27 (2) 149 -158 2006年 [査読無し][通常論文]
  • 藤田慎一, 橋本正則, 加我正行, 八若保孝 小児歯科学雑誌 44 (4) 556 -566 2006年 [査読無し][通常論文]
  • 歯科材料・器械 25 (1) 47 -53 2006年 [査読無し][通常論文]
  • 障がい者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト
    北海道・北海道歯科医師会 2006年 [査読無し][通常論文]
  • 歯科的協力度の向上を通して上顎中切歯の萌出誘導を行った障害児の一例
    障害者歯科 26 76 -82 2005年 [査読無し][通常論文]
  • 障害者歯科医療体制整備事業「北海道障害者歯科医療協力医制度」実地研修『講義』テキスト2
    北海道・北海道歯科医師会 2005年 [査読無し][通常論文]
  • Yasutaka Yawaka, Masakazu Osanai, Youichi Shirai, Tomokazu Hasegawa, Masayuki Kaga, Haruhisa Oguchi Pediatric Dental Journal 14 (1) 121 -126 2004年 [査読無し][通常論文]
     
    Roots of human deciduous teeth with apical periodontitis frequently show abnormal resorption as well as cementum deposition, and features that are different from those of physiological root resorption. The aim of this study was to determine the relationship between the appearance of cultured osteoclasts and the condition of dentin slices of human deciduous teeth. Bone marrow obtained from femora of 3- and 4-week-old male C57BL/6 mice was used for cell culture. The cells used in this study were osteoclasts, bone cells and bone marrow cells. Root dentin slices were prepared from human deciduous teeth with apical periodontitis (group 1) and from sound deciduous teeth (group 2, control group). The dentin surfaces were polished with grindstones. Cell suspension in α-MEM supplemented with 10% fetal bovine serum was seeded on the dentin slices and incubated for 96 hours at 37°C under 5% CO2 in air. After incubation, specimens were removed and fixed with glutaraldehyde and paraformaldehyde, and then tartrate-resistant acid phosphatase (TRAP) activity, which is considered to be specific to osteoclasts and odontoclasts, was detected. The number of TRAP-positive cells on the dentin were calculated by light microscopic observation. Specimens were then prepared and observed under a scanning electron microscope (SEM). TRAP-positive cells, visible as small red dots, were observed on dentin slices of both groups (n=50: each group). The densities of TRAP-positive cells in group 1 and group 2 were 2.98±2.57 cells / mm2 and 2.90±2.22 cells/mm2, respectively. The difference between densities of TRAP-positive cells in group 1 and group 2 was not significant by the Mann-Whitney U-test (P> 0.05). Shallow resorbed lacunae were observed on the specimens by scanning electron microscopy. It was shown that root dentin with apical periodontitis was resorbed by clastic cells such as cultured osteoclasts, suggesting that cell growth on dentin is not affected by apical periodontitis. Key words Apical periodontitis, Cultured osteoclasts, Human deciduous teeth, Root resorption, Tartrate-resistant acid phosphatase (TRAP). © 2004, The Japanese Society of Pediatric Dentistry. All rights reserved.
  • Y Yawaka, M Osanai, A Akiyama, R Ninomiya, H Oguchi ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER 185 (4) 335 -341 2003年07月 [査読無し][通常論文]
     
    Physiological root resorption is a characteristic feature of human deciduous teeth. Pathological root resorption due to apical periodontitis, dental trauma or excessive orthodontic force is also observed in deciduous roots. The root resorption is not continuous, and has resting periods. In the resting period, cementum deposits in resorbed root surface. The deposited cementum in permanent teeth has been reported in detail. However, the deposited cementum in deciduous teeth is unclear. The present study examined apices of roots of human deciduous incisors with apical periodontitis and roots of sound deciduous incisors by light and transmission electron microscopy. Root dentin and original cementum had a severe irregular caved surface. Cementum was partially deposited on the caved root surfaces. The deposited cementum had made the caved root surface relatively flat. The cementum was lax and had some defects. The deposited cementum was belt-like in shape and had a stratified structure. Each layer had various structures consisting of abundant microfibrils and fine granular materials, microfibrils, granular materials, and collagen fibrils, a few fibrils and granular materials and a relatively homogeneous structure. The original cementum had many collagen fibrils, such as intrinsic and extrinsic fibers, and no granular materials or homogeneous structure. Therefore, structure of the deposited cementum was very different from that of original cementum in deciduous teeth and from that of deposited cementum in permanent teeth.
  • "Changes in occlusal contact area and average bite pressure during treatment of anterior crossbite in primary dentition."
    The journal of Clinical Pediatric Dentistry 28 75 -80 2003年 [査読無し][通常論文]
  • 菊地友絵, 八若保孝, 中尾加代子, 弘中祥司, 加我正行, 小口春久 『小児歯科学雑誌』 41 (1) 271 -277 2003年 [査読無し][通常論文]
  • 中尾加代子, 八若保孝, 菊地友絵, 弘中祥司, 加我正行, 小口春久 『小児歯科学雑誌』 41 (1) 278 -284 2003年 [査読無し][通常論文]
  • Y. Yawaka, M. Kaga, M. Osanai, A. Fukui, H. Oguchi International Journal of Paediatric Dentistry 12 (1) 53 -60 2002年01月 [査読無し][通常論文]
     
    Apical periodontitis after pulp therapy in a primary tooth can cause delayed eruption of the permanent successor. A case of bilateral delayed eruption of mandibular premolars is presented. The patient, a 13-year-old girl, was referred by her dentist. Oral findings showed that the right first and left second primary molars were retained. Other premolars had erupted. An orthopantomogram revealed apical periodontitis, affecting both retained primary molars. The right first mandibular premolar was impacted against the alveolar bone and root of the second premolar, and there was a large cystic lesion in close association with the left second mandibular premolar. Both primary molars were extracted, and the cystic lesion was treated by marsupialization. Fenestration and traction were performed on the right first premolar. Correct tooth alignment was achieved with orthodontic appliances. If the problem had been detected earlier, treatment of the premolars might have been easier. Clinical and radiological follow-up, therefore, of primary teeth that have undergone pulp therapy procedures should be performed until eruption of succedaneous teeth.
  • S Takeyama, Y Yoshimura, Y Shirai, Y Deyama, T Hasegawa, Y Yawaka, T Kikuiri, A Matsumoto, H Fukuda BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 276 (2) 524 -529 2000年09月 [査読無し][通常論文]
     
    In coculture with osteoblastic cell line MC3T3-E1 (El) and mouse bone marrow cells, we reported that numbers of osteoclasts rose significantly on exposure to a low-calcium environment. Here we examined how osteoblasts influence osteoclastogenesis under a low-calcium environment. Comparing low extracellular calcium with a regular calcium environment, osteoprotegerin ligand (OPGL)/osteoclast differentiation factor (ODF) mRNA expression show more increase in the culture of low-calcium environment than in that of a regular calcium environment. Calcium-sensing receptor (CaSR), which was supposed as one of the mechanisms of recognizing extracellular calcium, existed on the surface of El cells. When El cells stimulated with agonists of CaSR, gadolinium, and neomycin, OPGL/ODF mRNA expression decreased. Moreover, these agonists reduced osteoclast formation in coculture. Taken together, it is possible that osteoblasts may recognize extracellular calcium via CaSR and regulate osteoclastogenesis. (C) 2000 Academic Press.
  • T Domon, M Osanai, Y Yawaka, R Suzuki, S Takahashi, T Yamamoto, M Wakita ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER 182 (2) 175 -184 2000年03月 [査読無し][通常論文]
     
    Resorption of deciduous teeth is not continuous, but alternates with periods of repair or rest. Dentine surfaces in periods of rest or repair resume resorption by odontoclasts during physiological root resorption of the deciduous teeth. However, no observations of such dentine surfaces have been shown. The characteristic feature of the dentine surfaces resuming resorption remains unknown. Tartrate-resistant acid phosphatase activity (TRAP) was detected on human deciduous teeth. The root resorbing surfaces on these teeth were photographed with a whole-mount light microscope, and the photographed areas were serially sectioned into 0.5 mu m semithin sections. Preodontoclasts and odontoclasts were three-dimensionally reconstructed. On root resorbing surfaces, areas with small scattered TRAP-positive cells were observed among areas with many TRAP-positive resorbing odontoclasts and TRAP-negative areas. The sections showed that areas with small scattered TRAP-positive cells have features similar to those of TRAP-negative areas, but there were three kinds of characteristic TRAP-positive cells: preodontoclasts, odontoclasts forming small lacunae, and preodontoclasts and odontoclasts with cytoplasmic processes extending to the dentine surface, which is covered with cells. These results suggest that the areas with small scattered TRAP-positive cells could be at the stage of resuming resorption, and show that the presence of preodontoclasts and odontoclasts with cytoplasmic processes extending to the covered dentine surface is a characteristic feature of the dentine surface at this stage.
  • Y Shirai, Y Yoshimura, Y Yawaka, T Hasegawa, T Kikuiri, S Takeyama, A Matsumoto, H Oguchi BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 265 (2) 484 -488 1999年11月 [査読無し][通常論文]
     
    We have been researching with the purpose of understanding the hard organization mineralization-suppression mechanism under a low calcium environment. So far, we have discerned clearly that the femur of an incubated newborn rat under a low calcium environment will develop bone formation dyscrasia such as hypertrophy of the caput. In this experiment, MC3T3-E1 (El) cells, which are osteoblast-like cells, and mouse bone marrow were incubated in a coculture system under a low calcium environment and manifestation of osteoblast cells and their ability to resorb were examined. The results suggested that as the calcium concentration in the medium decreased manifestation of osteoclast cells increased, and as the degree of mineralization of El cells advanced, the number of manifestation of osteoblast cells decreased. We, therefore, report that there is a possibility that extracellular calcium concentrations involve the process of differentiation of bone marrow cells into osteoblast cells. (C) 1999 Academic Press.
  • 秋山明美, 八若保孝, 原田理恵, 長内正数, 雨宮あきら, 小口春久 小児歯誌 36 (1) 144 -153 1998年 [査読無し][通常論文]
  • 八若保孝, 長内正数, 秋山明美, 小島寛, 小口春久 『小児歯科学雑誌』 35 (5) 812 -820 1997年 [査読無し][通常論文]
  • 小島 寛, 三浦 真理, 八若 保孝, 小口 春久 『小児歯科学雑誌』 34 (1) 259 -268 1996年 [査読無し][通常論文]
  • "The process of physiological root resorption : Relationship between resorbed root volumes and resorption of cronal pulp chamber wall"
    Pediatric Dental Journal 6 107 -113 1996年 [査読無し][通常論文]

共同研究・競争的資金等の研究課題

  • 乳歯列不正咬合に関する形態学的および機能学的研究
    研究期間 : 1992年
  • The molphological and functional study of malocclusion in primary dentition
    研究期間 : 1992年
  • 乳歯の生理的歯根吸収および病的異常吸収に関する組織学および分子生物学的研究
    研究期間 : 1989年
  • Histological and molecular biological study of physiological and pathological root resorption in primary teeth.
    研究期間 : 1989年

教育活動情報

主要な担当授業

  • 大学院共通授業科目(一般科目):自然科学・応用科学
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : 死因究明、人の死、内因死、外因死、異状死、法律、死後画像、医療安全、法歯学
  • 基本医学総論
    開講年度 : 2019年
    課程区分 : 修士課程
    開講学部 : 医学院
    キーワード : 死因究明、Autopsy imaging、病理解剖、法医解剖、医療安全 cause of death investigation, Autopsy imaging, autopsy (pathology and forensic medicine), hospital safety management
  • 医学総論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 医学院
    キーワード : 死因究明、Autopsy imaging、病理解剖、法医解剖、医療安全 cause of death investigation, Autopsy imaging, autopsy (pathology and forensic medicine), hospital safety management
  • 歯学研究概論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 歯学研究,基本的研究技法,基礎知識
  • 歯学研究概論
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 歯学研究,基本的研究技法,基礎知識
  • 法医学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 法医学、法歯学、死因究明
  • 法歯学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 法歯学、歯、個人識別
  • 発表・論文執筆法演習Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 発表・論文執筆法演習Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 発表・論文執筆法演習Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 発表・論文執筆法演習Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 発表・論文執筆法演習Ⅲ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 発表・論文執筆法演習Ⅲ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 研究計画,文献検索,研究のまとめ,口頭発表,論文作製
  • 口腔機能学実習Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅲ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅲ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅳ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅳ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅴ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児歯科診療、障害者歯科診療
  • 口腔機能学実習Ⅴ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児歯科診療、障害者歯科診療
  • 咬合発達学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 咬合発達学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 小児口腔機能回復学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 小児口腔機能回復学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 小児口腔機能回復学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 小児口腔機能回復学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔機能回復,歯科材料,硬組織,生体親和性
  • 小児口腔発育学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔,発育,硬組織,代謝
  • 小児口腔発育学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔,発育,硬組織,代謝
  • 小児口腔発育学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔,発育,硬組織,代謝
  • 小児口腔発育学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔,発育,硬組織,代謝
  • 小児歯科学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児,口腔軟組織,硬組織
  • 小児歯科学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児,口腔軟組織,硬組織
  • 咬合発達学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 小児,咬合の育成,心身障害児の歯科治療
  • 咬合発達学
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 小児,咬合の育成,心身障害児の歯科治療
  • 小児口腔細胞分子生物学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔,発育,硬組織吸収・修復,代謝,分子生物学
  • 小児口腔細胞分子生物学研究Ⅰ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔,発育,硬組織吸収・修復,代謝,分子生物学
  • 小児口腔細胞分子生物学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学研究科
    キーワード : 口腔,発育,硬組織吸収・修復,代謝,分子生物学
  • 小児口腔細胞分子生物学研究Ⅱ
    開講年度 : 2019年
    課程区分 : 博士後期課程
    開講学部 : 歯学院
    キーワード : 口腔,発育,硬組織吸収・修復,代謝,分子生物学
  • 国際歯科学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 新渡戸カレッジ グローバル人材育成 国際交流 ショートビジット 国際性の涵養
  • 障害者歯科学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 障害者歯科、精神機能の障害、運動機能の障害、摂食嚥下機能の障害、言語機能の障害、感覚機能の障害、内部障害、地域医療、症候群
  • 小児歯科学
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 小児歯科学、小児の成長発育、小児の歯科治療、小児の咬合育成
  • 小児歯科学臨床実習Ⅰ
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 小児歯科、齲蝕治療、咬合誘導、予防処置、口腔保健指導、治療と介助、小児への接し方
  • 小児歯科学臨床実習Ⅱ
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 小児歯科、齲蝕治療、咬合誘導、予防処置、口腔保健指導、治療と介助、小児への接し方
  • 小児歯科学基礎実習
    開講年度 : 2019年
    課程区分 : 学士課程
    開講学部 : 歯学部
    キーワード : 小児歯科学、支台歯形成、乳歯用既製金属冠、ラバーダム防湿法、窩洞形成、歯内療法、保隙装置

大学運営

学内役職歴

  • 2014年4月1日 - 2016年3月31日 大学院歯学研究科副研究科長
  • 2016年4月1日 - 2017年3月31日 大学院歯学研究科副研究科長
  • 2017年4月1日 - 2018年3月31日 大学院歯学研究院副研究院長
  • 2018年4月1日 - 2020年3月31日 歯学部長
  • 2018年4月1日 - 2020年3月31日 大学院歯学院長
  • 2018年4月1日 - 2020年3月31日 大学院歯学研究院長
  • 2020年4月1日 - 2022年3月31日 歯学部長
  • 2020年4月1日 - 2022年3月31日 大学院歯学研究院長
  • 2020年4月1日 - 2022年3月31日 大学院歯学院長
  • 2014年4月1日 - 2016年3月31日 教育研究評議会評議員
  • 2016年4月1日 - 2018年3月31日 教育研究評議会評議員
  • 2018年4月1日 - 2020年3月31日 教育研究評議会評議員
  • 2020年4月1日 - 2022年3月31日 教育研究評議会評議員

委員歴

  • 2007年   日本外傷歯学会   理事   日本外傷歯学会
  • 2006年   アジア外傷歯学会   理事   アジア外傷歯学会


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