Japanese Journal of Oral Biology
Print ISSN : 0385-0137
Volume 40, Issue 6
Displaying 1-9 of 9 articles from this issue
  • Tadanori Furuya, Hiroyuki Ishikawa, Shinji Nakamura, Minoru Wakita
    1998 Volume 40 Issue 6 Pages 583-593
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    Hand-tracing is commonly used to record structural information from histological specimens. It is relatively troublesome and requires numerous steps to develop the figures and has poor precision.
    In computer-aided image processing, image data is normally treated as gray-scale data, restricting the use of image processing with histological specimens. Conventionally, stained specimens like hematoxylin-eosin are difficult to use in this way.
    The present study extracted structural information from hematoxylin-eosin stained specimens and treated them as full-color images. For this type of image processing, the maximum likelihood method, a static method was used in conjunction with an original program written by the authors.
    As a result, all processes from the first image of the histological specimen to the final image lasted for only about 20min.
    Further investigation is required to record the structure of teeth and bone automatically.
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  • Masatsugu Hirata, Yoko Iwamatsu, Koji Kindaichi, Reiichi Okuda, Manabu ...
    1998 Volume 40 Issue 6 Pages 594-610
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    The present study was designed to examine the structural characteristics of periodontal epithelial cells and cementoblasts forming acellular cementum using maxillary first molars of male Wistar rats aged 2-10 weeks. The periodontal epithelial cells, stained with antibodies against cytokeratin, laminin and type IV collagen, changed the pattern of their distribution from mesh to islands with an increase in animal age and often showed a disrupted basement membrane. The epithelial cells were numerous at the concave area of the root trunk and the inner area of the root branch, but scarce at the convex area of the root trunk and the outer area of the root branch. The cementoblasts adjacent to the acellular cementum were positive with an anti-osteocalcin antibody and alkaline phosphatase. The distribution and localization of the cementoblasts was almost the same as that of the periodontal epithelial cells. The undecalcified ground sections labelled with calcein and alizarin red S vitally displayed two labeling lines in cementum at the concave area of the root trunk and the inner area of the root branch but only one line at the convex area of the root trunk and of the outer area of the root branch. The present results suggest that the periodontal epithelium might have an important role in the differentiation of cementoblasts and acellular cementum formation.
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  • Akihide Yoshida
    1998 Volume 40 Issue 6 Pages 611-621
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    Transforming growth factor-β1 (TGF-β1, ) is one of the most potent local factors for modulating bone metabolism. The purpose of this study was to investigate the possible involvement of TGF-β1, in alveolar bone remodeling during experimental tooth movement. In 10-week-old male Wistar rats, the right maxillary molars were moved lingually with a fixed finger spring for 1, 3 and 7 days. The contralateral side was used as a control. The protein localization of TGF-β1 and TGF-β type II receptor was of the examined by immunohistology. In the tension zone, osteoblasts on day 3 and day 7 tooth movement were stained with antibodies for the cytokine and its receptor. Osteoclasts in bone-resorbing lacunae in the compression zone showed immunohistological staining for both proteins on day 1, 3, and 7. The strongest staining was found on day 3 of the tooth movement. Furthermore, mRNA levels of TGF-β1 and TGF-β type II receptor in the alveolar bone on day 3 of the tooth movement were measured by quantitative RT-PCR. TGF-β1 and the TGF-β type II receptor mRNA in alveolar bone significantly increased through the experimented tooth movement. Taken together, these data suggested that TGF-β1 and TGF-β type II receptor regulated bone formation and resorption during tooth movement.
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  • Kiyomi Koike, Shigeo Aiyama
    1998 Volume 40 Issue 6 Pages 622-631
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    Mucous cells were found in the terminal clusters and acini of the parotid gland in early postnatal mice. We examined the development of the parotid gland and histological changes in the properties of the secretory granules of the mucous cells using light and electron microscopy. No mucous cells were recognizable on the day of birth. The cells were observed one day after birth and increased gradually until the 5th day. The granules of the mucous cells showed an intensely positive reaction upon PA-Schiff and alcian blue staining and showed low electron density and a bipartite substructure with a central dense core and a rim of lower density. The central dense core increased gradually from the first day after birth and was entirely digestible with pronase. On and after the 7th day after birth, the mucous cells decreased gradually and disappeared ten days later.
    These findings suggest that many of the granules in the mucous cells change to serous granules, since mucous cells appear only within a limited period and that the granule cores contain protein and increase in size with development.
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  • Kaori Sato, Toshihiro Takahashi, Yoshihito Shimazu, Takaaki Aoba
    1998 Volume 40 Issue 6 Pages 632-640
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    The inhibitory activities of amino acids on the crystal growth of calcium apatite were examined using synthetic hydroxyapatite as seeds in dilute supersaturated solutions. Phosphoserine exhibited the strongest inhibition among the adsorbates tested, while dicarboxylic amino acids also provided partial inhibition in the concentration range up to 10mM. In particular, the inhibitory activity of aspartic acid (Asp) was stronger than those of glutamic acid and succinic acid by comparison on the basis of the total molecular concentration in the solution. Parallel experiments were also conducted to determine the adsorption parameters of Asp onto the seed crystals and to assess the effect of the Ca-Asp complex on the equilibrium free concentration of Asp and on the kinetics of precipitation. The results clearly indicate that even concerning a weak adsorbate such as Asp, the observed crystal growth inhibition can be interpreted in terms of the fractional coverage of specific adsorption sites and the formation of ion pairs with calcium, thereby decreasing the driving force (degree of supersaturation) for crystal growth.
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  • Anri Suzuki, Hiroaki Katsuragi, Kazuko Saito
    1998 Volume 40 Issue 6 Pages 641-647
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    We evaluated the bactericidal activity of 3 antimicrobial agents, minocycline (MINO), tetracycline (TC), and tosufloxacin (TFLX), when periodontopathic bacteria Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis adhered to or invaded cultured human gingival fibroblasts (Gin-1). Minimum bactericidal concentration (MBC) for each antimicrobial agent was obtained using microbroth dilution techniques. MBC for MINO, TC and TFLX against A. actinomycetemcomitans associated with Gin-1 were 6.25μg/ml, 12.5μg/ml and 3.13μg/ml respectively and those against Gin-1 associated P. gingivalis were 12.5μg/ml, 25μg/ml and 12.5μg/ml respectively. MBC significantly increased when these bacterial organisms were associated with Gin-1 cells; 8-16 times resistant in case of A. actinomycetemcomitans and 32-64 times in case of P. gingivalis. These results suggest that microbial adherence to and/or invasion in Gin-1 cells may result in increased resistance to some antibiotics.
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  • Yasunori Nakamura, Haruhiro Kuwashima, Tomohiko Kimura
    1998 Volume 40 Issue 6 Pages 648-655
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    The effects of domiphen bromide (DB) and dequalinium chloride (DC), in comparison with cetylpyridinium chloride (CPC), on water-insoluble glucan (WIG) synthesis by glucosyltransferases (GTase) purified from S. sobrinu 6715 or S. mutans MT6R were determined. The morphological effects of the three drugs on WIG were observed under scanning and transmission electron microscopes. The production of total WIG (sum of adherent and nonadherent WIG) by strain 6715 GTase decreased by increasing the concentration of all three drugs. The decrease in adherent WIG was prominent as compared with that in nonadherent WIG. The inhibitory effects of the three drugs on WIG synthesis were in the following order: CPC≥DC>DB. On the other hand, the production of total WIG by strain MT6R GTase was decreased by all three drugs in a concentration-dependent manner. Almost complete inhibition of adherent WIG production was achieved by the three drugs even at low concentrations. The inhibitory effects of the three drugs on WIG synthesis were in the follwing order: DC>CPC≥DB. These results indicate that DC and DB have an inhibitory action on GTase of serotype c strain, the same as CPC does. Electron microscopic experiments showed that networks and clumps of WIG were decreased by all three drugs. From these results, DC and DB are expected to be used for prevention of dental caries as rinsing agents.
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  • Masato Matsuo, Takatsuna Nakamura, Chen-Yao Su, Tokuyuki Shimomura, Ke ...
    1998 Volume 40 Issue 6 Pages 656-661
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
    Guided bone regeneration (GBR) with the use of a resorbable membrane was performed in an experimental bone cavity to investigate the relationship between bone regeneration and vascularization, evaluated by means of vascular resin cast models and scanning electron microscopy (SEM).
    Two beagle dogs weighing 12 to 15kg with clinically healthy periodontal tissue were studied. The mandibular third and fourth premolars were extracted bilaterally, and the dogs were held in stock for 12 weeks to allow the sockets to heal. On one side of the mandible, a square bone cavity was then formed in the alveolar bone and covered with a resorbable membrane. As a control, a cavity was similarly created on the contralateral side but left uncovered.
    Twelve weeks after the operation, the regenerated bone in the bone cavity was slightly concave and the bone height was higher in the GBR group than in the control. The membrane, which showed evidence of being resorbed, was found between the superficial vascular network of the oral mucosa and the regenerated alveolar bone. Blood vessels from the periosteum increased in caliber as they passed through the resorbed part of the membrane.
    Our results indicate that regardless of what type of membrane is used, it only acts as a barrier preventing the oral mucosa from migrating apically to the socket, thereby creating an environment that promotes the proliferation of cells in the socket. From the viewpoint of the microcirculation, the level reached by blood vessels arising from the periosteum might play an important role in determining the final height of regenerated alveolar bone in extraction sockets.
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  • Yasunori Sakakura, Eichi Tsuruga, Noriyuki Shide, Toshihiko Yajima
    1998 Volume 40 Issue 6 Pages 662-666
    Published: December 20, 1998
    Released on J-STAGE: June 11, 2010
    JOURNAL FREE ACCESS
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