Language：English   Publishing type：Research paper (scientific journal)  

The purpose of this study was to evaluate the mechanism of action and the inhibiting effects of two types of desensitizers against dentin demineralization using pre-demineralized hypersensitivity tooth model in vitro. In this study, we confirmed that a hypersensitivity tooth model from our preliminary experiment could be prepared by immersing dentin discs in an acetic acid-based solution with pH 5.0 for three days. Dentin discs with three days of demineralization were prepared and applied by one of the desensitizers containing calcium fluoro-alumino-silicate glass (Nanoseal, NS) or fluoro-zinc-silicate glass (Caredyne Shield, CS), followed by an additional three days of demineralization. Dentin discs for three days of demineralization (de3) and six days of demineralization (de6) without the desensitizers were also prepared. The dentin discs after the experimental protocol were scanned using swept-source optical coherence tomography (SS-OCT) to image the cross-sectional (2D) view of the samples and evaluate the SS-OCT signal. The signal intensity profiles of SS-OCT from the region of interest of 300, 500, and 700 µm in depth were obtained to calculate the integrated signal intensity and signal attenuation coefficient. The morphological differences and remaining chemical elements of the dentin discs were also analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. SS-OCT images of CS and NS groups showed no obvious differences between the groups. However, SS-OCT signal profiles for both the CS and NS groups showed smaller attenuation coefficients and larger integrated signal intensities than those of the de6 group. Reactional deposits of the desensitizers even after the additional three days of demineralization were observed on the dentin surface in NS group, whereas remnants containing Zn were detected within the dentinal tubules in CS group. Consequently, both CS and NS groups showed inhibition effects against the additional three days of demineralization in this study. Our findings demonstrate that SS-OCT signal analysis can be used to monitor the dentin demineralization and inhibition effects of desensitizers against dentin demineralization in vitro.

DOI： 10.3390/ma14081876

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.job.2020.09.007

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publisher：The Japanese Society of Conservative Dentistry  

<p> Purpose: Recently, the application of composite resin restorations has expanded. Although chromatic studies of composite resins have progressed, color differences measured by colorimeters and visual color evaluation do not always match. The aim of this study was to establish a method of evaluating the visual color of composite resins by using the visual analog scale (VAS), which evaluates subjective data as a continuous variable, and to examine its validity.</p><p> Method: One structural color composite resin (experimental resin : ECM-001) and three commercial composite resins of shade A3 were used in this study. Class Ⅴ and class Ⅲ cavities were prepared in artificial maxillary central incisors of four shades (A1, A2, A3, and A3.5) and each composite resin was filled and its color matching was evaluated on a black-and-white background using VAS. The correlation between VAS value and visual evaluation was analyzed. The color matching of teeth and composite resin were statistically analyzed using one-way analysis of variance and Tukey's HSD test (p<0.05). Background differences in the same sample were analyzed by the t-test (p<0.05).</p><p> Results: In the Class Ⅴ restoration, ECM-001 showed better color matching than other composite resins. In the Class Ⅲ restoration, ECM-001 showed excellent color matching with a wide range of teeth shades on the white background. The VAS values of the other composite resins were higher on the black background than on the white background. However, the VAS value of ECM-001 on the black background tended to decrease. Because the evaluation of VAS color matching by evaluators showed the same tendency, the VAS value reflects information that can be recognized by visual observation. It is suggested that the evaluation of VAS value correlates with visual evaluation.</p><p> Conclusion: It is suggested that the evaluation of color matching of composite resin restorations using VAS is useful for structural color composite resins, providing a new method of visually evaluating composite resin restorations.</p>

DOI： 10.11471/shikahozon.63.30

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Objectives: Self-adhesive resin cements contain functional monomers that enable them to adhere to the tooth structure without a separate adhesive or etchant. One of the most stable functional monomers used for chemical bonding to calcium in hydroxyapatite is 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). The aim of this study was to evaluate the influence of the10-MDP concentration on the bond strength and physical properties of self-adhesive resin cements. Materials and Methods: We used experimental resin cements containing 3 different concentrations of 10-MDP: 3.3 wt% (RC1), 6.6 wt% (RC2), or 9.9 wt% (RC3). The micro-tensile bond strength of each resin cement to dentin and a hybrid resin block (Estenia C&B, Kuraray Noritake Dental) was measured, and the fractured surface morphology was analyzed. Further, the flexural strength of the resin cements was measured using the three-point bending test. The water sorption and solubility of the cements following 30 days of immersion in water were measured. Results: The bond strength of RC2 was significantly higher than that of RC1. There was no significant difference between the bond strength of RC2 and that of RC3. The water sorption of RC3 was higher than that of any other cement. There were no significant differences in the three-point bending strength or water solubility among all three types of cements. Conclusions: Within the limitations of this study, it is suggested that 6.6 wt% 10-MDP showed superior properties than 3.3 wt% or 9.9 wt% 10-MDP in self-adhesive resin cement.

DOI： 10.5395/rde.2019.44.e45

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Language：Japanese   Publisher：岡山歯学会  

歯学部学生の臨床前基礎実習において透明根管模型歯は、全ての学生が同一条件下で実習を行えることや、根管治療における各ステップを目視できる等の利点がある。今回、本学歯学部4年次生47名が象牙質歯髄複合体診断・治療学実習の実技試験で根管充填を行った透明根管模型歯について、視診による評価と、デジタルX線画像のモニタ上での視診による評価、およびデジタルX線画像を画像解析ソフト(ImageJ)により解析した評価を行い、各評価法の妥当性について比較検討した。その結果、画像解析ソフトで解析する方法は成績の過小評価を防ぐうえで有用であり、より客観的な評価が可能と考えられた。

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Language：Japanese   Publisher：The Japanese Society of Conservative Dentistry  

<p> Purpose: Clinically, resin composite repair for dentin hypersensitivity with substantial defects such as wedge-shaped defects is commonly performed a few days after applying the densensitizer to dentin. In this study, we investigated the influence of pre-treatment of dentin densensitizers on bond strength.</p><p> Materials and Methods: We applied three desensitizers (MS coat ONE, F Varnish, and Nanoseal) on an artificial model of hypersensitive dentin using human premolars, and observed the surface structure by scanning electron microscope (SEM). Then, the specimens to which the three desensitizers had been applied were treated with Clearfil Mega Bond FA. We morphologically observed by SEM the surface of dentin which had been treated with the primer. Furthermore, the micro-tensile bond strength (μTBS) for the specimens which were incrementally built up by resin composites was measured in a universal testing machine. The interface between resin and dentin of specimens was observed by SEM and confocal laser scanning microscope (CLSM).</p><p> Results: The surfaces of specimens to which each desensitizer had been applied showed morphological characters having the effects of suppressing hypersensitivity. Regarding μTBS, there were no significant differences among all groups. In the group of MS coat ONE, MS coat ONE was not completely removed by the application of Mega Bond FA primer. Although the penetrations of the primer into dentin tubules were small, the thickness of the bond layer was greater. The specimens of F Varnish showed the functions of self-etching adhesive systems, because the varnishes had been partially removed by Mega Bond FA primer. In the group of Nanoseal, Mega Bond FA primer was almost removed by Nanoseal, and penetrated deeply into the dentinal tubules.</p><p> Conclusion: The three desensitizers used in this study had no effect on the bond strength of self-etching adhesive systems to the artificial model of hypersensitive dentin.</p>

DOI： 10.11471/shikahozon.60.22

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Language：English   Publisher：Japanese Association of Regenerative Dentistry  

<p>The purpose of this study was to evaluate the effects of aging on bone formation induced by Bone Morphogenetic Protein-2 (BMP-2) using low-intensity pulsed ultrasound (LIPUS)in 12-week-old (12w group) and 70-week-old (70w group) Wistar rats.</p><p>The experimental sites (palatal subperiosteal sites) were divided into three sites as follows: BMP site, BMP-2 was implanted; LI-BMP site, LIPUS treatment was performed every three days after implantation of BMP-2; and Control site, neither implantation of BMP-2 nor LIPUS treatment was done.</p><p>At 3 weeks after surgery, thickness of new bone (TNB) was significantly higher in both the BMP and LI-BMP sites than in the Control site (P<0.05). TNB of every site in the 12w group was significantly higher than that of the same experimental site in the 70w group (P<0.05). Newly formed bone was almost integrated with original bone at the LI-BMP site.</p><p>These results suggest that LIPUS enhances the maturation of bone formation induced by BMP-2 even in senescent rats, although the volume of bone decreased with aging.</p>

DOI： 10.11223/jarde.14.65

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Language：English   Publisher：Japanese Association of Regenerative Dentistry  

Tissue regeneration is the important issue in the field of operative dentistry. In the previous study, we demonstrated that TNFα activates the potential for totipotency in human bone marrow mesenchymal stem cells (hMSCs) and leads to the regeneration of target cells or tissues along with the appropriate differentiating factor such as Emd-Gel. In this study, we apply the transcription factor set of TNF-α and Amelogenin to the human adipose-derived stem cells (hASCs) and our results indicate that this transcription factor set differentiate hASCs into odontblasts simillary and suggest that TNFα activates potential totipotency of hASCs and the activation can lead to the regeneration of target cells or tissues

DOI： 10.11223/jarde.13.131

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Language：English   Publisher：日本再生歯科医学会  

酸腐食象牙質への樹脂の浸透が不完全な場合は、ハイブリッド層に水分の多い、樹脂の少ない領域(隙間)が残ってしまい、樹脂や微細繊維の分解を引き起こすと推測される。実験的樹脂にヒドロキシアパタイト(Hap)を加えると、微小隙間をリン酸カルシウムで満すことができると考え、その仮説について検証した。0、5、10wt%のHApを加えた樹脂を作成した。この樹脂について、水分吸着と可溶性評価、カルシウム沈着誘導の評価、走査型電子顕微鏡観察とエネルギー分散X線分析、引張り試験を行った。その結果、HApは象牙質への樹脂の浸透には効果がなかったが、歯科用接着剤にHApを添加するとハイブリッド層の下に結晶を形成させ、強いアンカーになることが示唆された。

DOI： 10.11223/jarde.13.85

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Authorship：Lead author   Language：Japanese   Publisher：(NPO)日本歯科保存学会  

Purpose: By incorporating sodium fluoride in adhesive resin cement, the release of fluoride from the cement is expected to strengthen the teeth and prevent secondary caries. However, there is a concern that such fluoride incorporation and release could impair the physical properties of the cement. In this study, we investigated the influence of incorporating sodium fluoride on the flexural strength, water absorption and solubility of adhesive resin cement.<br> Materials and Methods: The experimental resin cements were prepared at concentrations of 0-20 wt% sodium fluoride. The amounts of fluoride released from the cements were measured from day 1 to day 84. Next, a three-point bending test of the experimental resin cements was performed after initial curing (24 hours storage in water at 37°C) and after thermal cycle loading (5°C-55°C, 10,000 times). Furthermore, water absorption and solubility following 30 days immersion in water were measured.<br> Results: Fluoride release increased with an increase in the content rate of sodium fluoride. After initial curing, the three-point bending strengths of 5 wt% and 10 wt% sodium fluoride compounded cement were not statistically decreased compared to those of sodium fluoride 0 wt%, but were significantly reduced by incorporation of more than 15 wt%. There were no significant differences in the strength between 15 wt% sodium fluoride compounded cement and 20 wt% sodium fluoride compounded cement. Similar results were also observed in the comparison of flexural strength after thermal cycle loading. Regarding the 30-day water absorption amount, there was no significant difference between 5 wt% sodium fluoride compounded cement and that of 0 wt% sodium fluoride cement. However, the 30-day water absorption of 10 wt% sodium fluoride compounded cement was significantly increased compared to that of 0 wt% sodium fluoride compounded cement. The solubility was not significantly different between the content rate of 0-10 wt% sodium fluoride.<br> Conclusion: Increasing the sodium fluoride content improved the amount of fluoride release. On the other hand, the flexural strength of the cement was decreased, and the amounts of water absorption and solubility were increased. Within the limit of this study, it is suggested that 10 wt% sodium fluoride compounded cement could provide fluoride release without decreasing mechanical strength.

DOI： 10.11471/shikahozon.58.10

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Other Link： http://search.jamas.or.jp/link/ui/2015218122

Authorship：Lead author   Language：Japanese   Publisher：岡山歯学会  

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症例は36歳女性で、主訴は上顎前歯部の色調と形態不良による審美障害であった。上下顎の中切歯と側切歯のエナメル質の損耗を認め、唇側歯頸部にう蝕を認めた。プラークコントロールは良好であった。パノラマ・デンタルX線で上顎中切歯は切縁のエナメル質が欠落し、歯冠長の短い像を認めた。問診で過去に摂食障害で嘔吐の繰り返しがあり、現在はパイナップル、梅酒、酢の物を好んで摂取していた。象牙質う蝕を併発した酸蝕と診断し、食生活の見直しとして酸性食の摂取量を控えるように指導し、唇面の歯質欠損とう蝕に対しては上顎で右側第一小臼歯から左側第一小臼歯までの8本、下顎で右側第一小臼歯から左側第二小臼歯までの9本、合計17本にコンポジットレジンによる修復処置を行った。臼歯部咬合面と前歯部舌面は症状がなく、臼歯部の咬合が安定しており修復処置は行わず経過観察とした。

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D-Glucosamine is a useful medicament in various fields of medicine and dentistry. With respect to stability of the cell membrane, it has been reported that bradykinin-induced nociceptive responses are significantly suppressed by the direct application of D-glucosamine. Electroporation is usually used to effectively introduce foreign genes into tissue culture cells. Buffers for electroporation with or without D-glucosamine are used in experiments of transfection vectors. This is the first study to indirectly observe the stability and protection of the osteoblast membrane against both electric stress and gene uptake (the proton sponge hypothesis: osmotic rupture during endosomes prior to fusion with lysosomes) in electroporation with D-glucosamine application. The transfection efficiency was evaluated as the fluorescence intensity of the transfected green fluorescent protein (GFP) in the cultured cells (osteoblasts; NOS-1 cells). The transfection efficiency increased over 30% in the electroporation samples treated with D-glucosamine-supplemented buffer after one day. The membrane absorption of D-glucosamine is the primary mechanism of membrane stress induced by electric stress. This new function of D-glucosamine is useful and meaningful for developing more effective transformation procedures.

DOI： 10.1155/2014/485867

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Language：Japanese   Publisher：The Japanese Society of Conservative Dentistry  

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Purpose: The purpose of this study was to evaluate penetration of self-etching primer to human sound dentin using confocal laser scanning microscope (CLSM) with fluorescent dye. Methods: The fluorescent dye Rhodamine B was mixed into self-etching primer of Clearfil Mega Bond FA (Kuraray Noritake Dental) at the concentration of 0, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1%, or 0.2%. All dentin surfaces were treated with Clearfil Mega Bond FA. Resin composites (Clearfil AP-X) were built up incrementally according to the manufacturer's instruction. 64 specimens were subjected to the observation of the interface of resin and dentin with CLSM and SEM. The 32 specimens were then serially sectioned into multiple sliced parts and then micro-tensile bond strength (MTBS) was measured in a universal testing machine. Results: Penetration of monomer into dentin via dentinal tubules was observed as moderate in the group of 0.07, 0.08, 0.09% and 0.1%. On the other hand, in the group of 0.2%, the color of Rhodamine B was too dark to identify the details of the dentinal tubules. There was no significant difference in the MTBS between the group of 0.05, 0.06 or 0.07% and control (p>0.05). The MTBS produced by the group 0.08, 0.09, 0.1% or 0.2% were significantly different from control (p<0.05). Conclusion: This study suggested that the application of CLSM was effective to evaluate penetration of self-etching primer to dentin. A high concentration of Rhodamine B influenced the bond strength. It was suggested that the appropriate concentration of Rhodamine B was 0.07% in the Mega Bond FA Primer.

DOI： 10.11471/shikahozon.56.310

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS AS  

Objective. To evaluate the surface characteristics of indirect composites etched with acidulated phosphate fluoride (APF) solution. Material and methods. APF solution was applied to specimens of six composite materials. The surface morphological change was measured with a confocal laser scanning microscope. Gloss measurement and scanning electron microscope (SEM) observation were also performed. Results. The APF-treated surface showed various patterns due to the difference in the filler incorporated in each composite. The surface properties could be evaluated precisely from the surface roughness parameters. The arithmetical mean deviation of roughness profile (Ra) parameter of the specimens treated with APF solution was higher than those of the specimens untreated with APF, except New Meta Color Infis (IF). The difference in etching influence of each composite material was shown conclusively in the maximum height of the profile (Rz) parameter. Gradia (GR) and Gradia Forte (GF) were etched three times more deeply than that of IF categorized microfilled composite. The mean width of the profile element (RSm) decreased significantly after APF treatment, except in IF. Gloss was reduced apparently in all materials, indicating that gloss reduction was sensitive to slight surface changes. Conclusions. Specific filler particles of prosthodontic composite materials were etched by APF application. The surface roughness parameters, such as Rz and RSm, properly described various surface topographic features. Gloss was strongly correlated to surface roughness, as defined by these parameters, and especially to the initial change of surface roughness.

DOI： 10.1080/00016350903070911

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Language：English   Publisher：Nihon University School of Dentistry  

Clearfil DC Bond (DC) is a new single-step, dual-cure bonding agent. In this study, the shear bond strengths of a core build-up composite to dentin used with four bonding systems [DC, Unifil Core Self-Etching Bond (UC), Clearfil SE Bond (SE) and Cleafil tri-S Bond (TS)] were measured. The bonding ability after 7 days of storage and in vitro durability following 20,000 thermocycles were also evaluated. The bond strength of DC did not differ significantly from those of other bonding systems after 24 hours of storage. Another dual-cure bonding system, UC, showed a significant reduction of bond strength after 7 days of storage. On the other hand, the bond strength of TS, a light-cured bonding system with a similar composition to DC, was reduced significantly following 20,000 thermocycles. SE, a two-step light-cure bonding system in the same series as DC, provided superior bond strength under all conditions. Although DC showed a slightly lower bond strength than SE, there was no significant difference between DC and SE under all conditions. Consequently, DC may be a useful and effective bonding system for multiple composite resin restorations. (J. Oral Sci. 50, 329-333, 2008)

DOI： 10.2334/josnusd.50.329

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Other Link： http://search.jamas.or.jp/link/ui/2009119971

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Chitosan is a natural polyaminosaccharide that is extensively applied as an antitumor and antirheumatic drug. However, there are few reports about its effects on hypofunctional osteoblasts in vitro. We investigated the biological characteristics of a human osteoblastic cell line (NOS-1 cells) that was cultured with a chitosan monomer-containing medium under simulated microgravity conditions. After 7 days of cell incubation under the conventional conditions, the flasks were transferred to a microgravity simulator for 3 days. In the 0.005% chitosan monomer supplemented group, the marker enzyme of biological mineralization, the alkaline phosphatase (ALP) activity, was significantly higher compared with the control group (p &lt; 0.05). A cDNA microarray was performed to investigate the effects on the mRNA level by chitosan monomer, and the fluorescent signal was analyzed. The interferon gamma (IFN-gamma) receptor gene was detected with a signal ration of 2.2. The slight increase of IFN-gamma receptor expression was confirmed after 3 days of incubation according to RT-PCR analysis. Western blot analysis also showed the increased expression of IFN-gamma receptor. These results suggest that a supra-low concentration of chitosan monomer may increase the ALP activity of osteoblastic cells through the IFN-gamma receptor at the early phase of cell culture and recover the activity for biological mineralization under the hypofunctional condition. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.31234

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Objectives: This study was designed to confirm the mechanical efficacy of chewing chitosan containing gum to suppress the growth of oral bacteria compared to a mouth rinse, and to demonstrate the increased salivary secretion due to chewing chitosan-containing gum.
Method: Twelve healthy subjects were recruited from among the staff and students of Nagasaki University School of Dentistry. For the slab of gum study, the subjects chewed chitosan-containing gum for 5 min and then rested for 5 min. For the testing of the chitosan mouth rinse solution, the subjects gargled 10 mL of solution for 30 s followed by resting for 9 min 30 s. These protocols were continuously repeated five times for 50 min on the same day. For the salivary secretion experiment, the gum chewing was repeated three times per day for 2 days.
Results: The amount of oral bacteria in the subjects who chewed chitosan-containing gum significantly decreased during all three sampling times except at 60 min for total bacteria in comparison to those in the rinse group. Chitosan-containing gum chewing also significantly increased the secretion of saliva.
Conclusions: Chitosan-containing gum chewing has a greater antibacterial effect and it also increases salivary secretion. The present findings strongly indicate that the application of natural materials such as chitosan is useful for both oral health and the quality of life. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jdent.2007.08.004

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Chitosan has a variety of biological activities. Although it has been reported that chitosan promotes osteogenesis in bone lesions, little is known about how it modulates the hard tissue forming cells at the gene level. This study focused on gene expressions in osteoblasts cultured with a super-low concentration of chitosan monomer. cDNA probes were synthesized from isolated RNA and labeled with fluorescent dye. They were hybridized with Human 3.8 II cDNA microarray, and the fluorescent signal was analyzed. cDNA microarray analysis revealed that 10 genes concerning to various signaling-related molecules were expressed at &gt;= 2.0-fold higher signal ratio levels in the experimental group when compared with the control group after 3 days. Real-time PCR analysis showed that chitosan monomer induced an increase in the expression of four signal transduction genes, mitogen-activated protein kinase (MAPK)K3, MAPKKK11, Rac1 and Shc1, together with the alkaline phosphatase gene. These results suggest that a super-low concentration of chitosan monomer could modulate the activity of osteoblastic cells through mRNA levels and that chitosan monomer directly affects signal transduction inside cells. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.31130

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Objective: We have already reported that chitosan inhibited the growth of cariogenic bacteria in vitro. This study was designed to evaluate whether chewing gum, containing chitosan, can effectively suppressed the growth of oral bacteria (total bacteria, total Streptococci, mutans streptococci (MS)) in saliva.
Methods: Fifty healthy subjects, ranging in age from 19 to 32 years, were recruited from among the staff and students of Nagasaki University School of Dentistry. For the slab of gum study, the subjects chewed gum for S min and then rested for 5 min. Each subject chewed a total of eight pieces of gum, which was either supplemented with or without chitosan, for a total of 80 min. Two different types of gums were examined with at least 1 week as a rest period in between treatments. This in vivo study was carried out by the double blind comparison test.
Results: The amount of oral bacteria was found to significantly decrease in the chitosan group. Especially, the number of MS were maintained at about a 20% level in comparison to that before gum chewing, even at 1 h after gum chewing.
Conclusion: These findings suggest that a supplementation of chitosan to gum is an effective method for controlling the number of cariogenic bacteria in situations where it is difficult to brush one's teeth, such as when an individual is away from home all day or participating in outdoor training. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.archoralbio.2006.10.004

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

The present study was undertaken to evaluate the applicability of chitosan monomer (D-glucosamine hydrochloride) as a Pulp capping medicament. Both hi vitro and in vivo experiments were carried out to study the cell metabolism and Wound healing mechanisms following the application of chitomonosaccharide. After 3 days of osteoblast culture, alkaline phosphatase (ALP) activity Significantly increased in the chitosan group. Reverse transcription polymerase chain reaction analysis revealed that chitosan induced an increase in the expression of ALP mRNA after 3 days and bone morphogenetic protein-2 mRNA after 7 days of osteoblast incubation. Inflammatory cytokine, interleukin (IL)-8, synthesis in fibroblasts was strongly suppressed in the medium Supplemented with chitosan monomer. Histopathological effects were evaluated in rat experiments. After day, inflammatory cell infiltrations were observed to be weak when compared with the application of chitosan polymer. After 3 days, a remarkable proliferation of fibroblasts was seen near the applied chitosan monomer. The inflammatory cell infiltration had almost completely disappeared. After 5 days, the fibroblastic proliferation progressed, and some odontoblastic cells appeared at the periphery of the proliferated fibroblasts. These findings indicate that the present study is the first report that chitosan monomer acts as a biocompatibly stable medicament even at the initial Stage Of wound healing in comparison with the application of chitosan polymer. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.30588

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DOI： 10.3353/omp.10.131

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Chitosan has a variety of biological activities. However, little is known about how chitosan modulates the hard tissue forming cells. When we cultured an osteoblastic cell line in alpha-MEM supplemented with 10% FBS and 0.005% chitooligosaccharide for 3 days, alkaline phosphatase (ALP) activity was significantly high compared with the control culture group (P &lt; 0.05). This study was focused on gene expression in osteoblasts cultured with water-soluble chitooligosaccharide. cDNA probes were synthesized from isolated RNA and labeled with fluorescent dye. They were hybridized with Human 1.0(R) cDNA microarray, and fluorescent signal was analyzed. cDNA microarray analysis revealed that 16 genes were expressed at greater than or equal to 1.5-fold higher signal ratio levels in the experimental group compared with the control group after 3 days. RT-PCR analysis showed that chitosan oligomer induced an increase in the expression of two genes, CD56 antigen and tissue-type plasminogen activator. Furthermore, the expression of mRNAs for BMP-2 was almost identical in the experimental and control groups after 3 days of culture, but slightly increased after 7 days of culture with chitosan oligomer. These results suggest that a super-low concentration of chitooligosaccharide could modulate the activity of osteoblastic cells through mRNA levels and that the genes concerning cell proliferation and differentiation call be controlled by water-soluble chitosan. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biomaterials.2003.08.022

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：LUIGI PONZIO E FIGLIO  

The present study was undertaken to evaluate the effects of pH and the degree of polymerization of chitosan on the inhibition of growth of Streptococcus mutans. Three types of chitosan, polymer, oligomer and monomer were used at 4% (W/V) and three different levels of pH: 6.0, 6.5 and 7.4. Bactericidal activity was calculated by the growth ratio. Chitosan oligomer significantly inhibited bacterial growth at a pH value of 6.5. All three types of chitosan strongly inhibited bacterial growth at pH 6.0. Furthermore, nearly complete inhibition was obtained with 2%(W/V) chitosan solution at constant pH 6.5. This study is the first to report that water-soluble chitosan directly suppresses the growth of the typical cariogenic bacterium S. mutans even at pH 6.5, without causing demineralization of the tooth surface.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Chitosan is a natural bioactive material. Although it has been reported that chitosan promotes osteogenesis in bone lesions, little is known about how chitosan modulates this process. The present study was designed to investigate the effect of water-soluble chitosan relative to initiation of biologic mineralization, especially in the matrix-vesicles-(MVs) mediated process in vitro. A human osteoblastic cell line (NOS-1) was used. After 3 days of incubation, the number of cells and alkaline phosphatase (ALP) activity increased significantly in the chitosan group. RTPCR analysis revealed that chitosan induced an increase in the expression of bone morphogenetic protein-2 mRNA after 7 days of incubation. MVs were isolated from NOS-1 cells using a collagenase digestion and ultracentrifugation method. ALP activity of MVs isolated from chitosan-supplemented cells was significantly higher than that of the control group. Furthermore, isolated MVs were incubated in medium supplemented with Na-beta-glycerophosphate without fetal bovine serum. Needle-like crystals were observed in association with MVs after 24h of incubation. These needle-like crystals were densely accumulated in the chitosan group. The present findings suggest that water-soluble chitosan would promote osteoblast proliferation and differentiation and may be useful for the acceleration of initial biologic mineralization.

DOI： 10.1002/jbm.a.10009

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：LUIGI PONZIO E FIGLIO  

Matrix vesicles (MV) having high alkaline phosphatase (ALP) activity act as initiators of biological mineralization. Although bacteria have similar membranous structures to MV. ALP mediated mineralization has not been studied in bacterial cells. Escherichia coli was transformed with a bacterial ALP gene in this study. Recombinant E. coli overproducing ALP induced mineralization through hydrolysis of calcium-glycerophosphate (Ca-GP). Fourier transform infrared spectroscopy and electron microscopy combined with electron diffraction revealed newly formed hydroxyapatite mineral deposits. These findings suggest that hydrolysis of Ca-GP through ALP induced high Ca and Pi concentrations within bacterial cells followed by complete bacterial mineralization.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER  

A 16-kDa protein, identical to the a-crystallin-like stress protein, was induced under O-2-deficient culture conditions and bound principally to the 30S ribosomal subunits of Mycobacterium bovis BCG substrain Tokyo (BCG). The 16-kDa protein was shown to be tightly associated with the ribosome.

DOI： 10.1016/S0923-2508(98)80301-X

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS LTD  

The component of mycobacterial 85 complex (85A, 85B, and 85C) and MPB51 are very important from immunological, biochemical, and antimycobacterial points of view. In this study, the transcriptional properties of genes encoding three components of 85 complex and MPB51 from BCG were analysed. The authors' analyses revealed that genes for 85A and MPB51 were transcribed as a single unit despite the one operon-like structure and these four genes were probably under a different regulatory control. These findings may help to understand the immunological and physiological roles of these antigens. (C) 1997 Academic Press Limited.

DOI： 10.1006/mpat.1997.0159

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

A novel 18-kDa heat shock protein, HrpA, has been identified from Mycobacterium bovis BCG. HrpA was rapidly synthesized in membrane and ribosome fractions but not in the cytoplasmic fraction under heat shock stress. HrpA bound tightly to 70S ribosomes, mainly in 30S subunits. HrpA might be involved in the initiation step of translation at high temperature.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

The components of the fibronectin-binding antigen 85 complex (85A, 85B, and 85C) and the related protein MPB/MPT51 are major secreted proteins in Mycobacterium tuberculosis and Mycobacterium bovis BCT;, The fbpA, fbpC, and mpt51 genes encoding 85A, 85C, and MPT51, respectively, were isolated from Mycobacterium avium and sequenced in this study, The structures of these genes, and that of the fbpB gene encoding the 85B protein, were conserved in these three species. The secreted amounts of 85A, 85B, 85C, and MPB/MPT51 were compared for M. tuberculosis, BCG, and M, avium, These four proteins were found in large amounts in the culture filtrates from M. tuberculosis and BCG, In contrast, in the culture filtrate from M. avium, 85B and MPT51 were abundant whereas 85A and 85C were hardly found, in spite of the presence of the encoding genes, The difference in the secretion amounts might be regulated at the transcription level, These facts might reflect host immunopathogenesis, the protective immunities against infections, and the drug susceptibilities of these organisms.

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL SCIENCE LTD  

The recombinant bacillus Calmette-Guerin (rBCG) secretion system utilizing an extracellular alpha antigen of Mycobacterium kansasii (alpha-K) was characterized biochemically and immunologically. The human immunodeficiency virus type1 (HIV-1)p17(gag) B cell epitope fused to alpha-K was secreted in extremely large amounts. At least three mice out of seven inoculated with rBCG generated high titres of antibody to the epitope. The long-lasting antibody production persisted more than 14 months.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BUTTERWORTH-HEINEMANN LTD  

The live bacterial vaccine Mycobacterium bovis BCG (BCG) is a vehicle worth noticing for various protective antigens. The gene encoding the B-cell epitope of the oligopeptide repeating in the circumsporozoite protein (C.S. protein) of the rodent malaria parasite, Plasmodium yoelii, was inserted into the plasmid vector under the control of an expression cassette carrying the promoter and signal sequence of the a antigen derived from Mycobacterium kansasii (k-a). The B-cell epitope was successfully expressed and secreted from BCG as a fusion protein with k-a. This recombinant BCG was administered subcutaneously into BALB/c mice and the antibody production was measured by the enzyme-linked immunosorbent assay (ELISA). Long lasting humoral response was found in one of seven mice.

DOI： 10.1016/0264-410X(95)00131-J

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Language：English   Publishing type：Research paper (scientific journal)  

The secreted protein MPB51 is one of the major proteins in the culture filtrate of Mycobacterium bovis BCG (BCG) and is a protein immunologically cross-reacting with the fibronectin binding 85 complex secreted by this bacterium. The gene encoding MPB51 (mpb51) was cloned, sequenced, and expressed in Escherichia coli. The mpb51 gene was mapped downstream of the gene for 85A component with 179 bp spaces. The mpb51 gene encoded 299 amino acids, including 33 amino acids for the signal peptide, followed by 266 amino acids for the mature protein with a molecular mass of 27807.37 Da. This is the first complete sequence of MPB51. MPB51 showed 37-43% homology to the components of 85 complex. Two-dimensional electrophoresis of culture fluids of BCG and Western blotting indicated the existence of the other novel protein(s) which strongly cross-reacted with the alpha antigen (85B) and MPB51.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Actinomycetes Japan  

DOI： 10.3209/saj.9_228

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Other Link： http://search.jamas.or.jp/link/ui/1996082802

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Language：English   Publisher：OXFORD UNIV PRESS UNITED KINGDOM  

DOI： 10.1093/nar/21.15.3579

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Language：English   Publisher：The Japan Society of Mechanical Engineers  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：長崎大学  

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Event date： 2001

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