239 research outputs found

    Histological comparison of three apatitic bone substitutes with different carbonate contents in alveolar bone defects in a beagle mandible with simultaneous implant installation

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    Since bone apatite is a carbonate apatite containing carbonate in an apatitic structure, carbonate content may be one of the factors governing the osteoconductivity of apatitic bone substitutes. The aim of this study was to evaluate the effects of carbonate content on the osteoconductivity of apatitic bone substitutes using three commercially available bone substitutes for the reconstruction of alveolar bone defects of a beagle mandible with simultaneous dental implant installation. NEOBONE®, Bio-Oss®, and Cytrans® that contain 0.1 mass%, 5.5 mass%, and 12.0 mass% of carbonate, respectively, were used in this study. The amount of newly formed bone in the upper portion of the alveolar bone defect of the beagle’s mandible was 0.7%, 6.6%, and 39.4% at 4 weeks after surgery and 4.7%, 39.5% and 75.2% at 12 weeks after surgery for NEOBONE®, Bio-Oss®, and Cytrans®, respectively. The results indicate that bone-to-implant contact ratio was the largest for Cytrans®. Additionally, the continuity of the alveolar ridge was restored in the case of Cytrans®, whereas the continuity of the alveolar ridge was not sufficient when using NEOBONE® and Bio-Oss®. Both Cytrans® and Bio-Oss® that has a relatively larger carbonate content in their apatitic structure was resorbed with time. We concluded that carbonate content is one of important factors governing the osteoconductivity of apatitic bone substitutes

    Effects of acidic calcium phosphate concentration on setting reaction and tissue response to β-tricalcium phosphate granular cement

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    Beta-tricalcium phosphate granular cement (β-TCP GC), consisting of β-TCP granules and an acidic calcium phosphate (Ca-P) solution, shows promise in the reconstruction of bone defects as it sets to form interconnected porous structures, i.e., β-TCP granules are bridged with dicalcium phosphate dihydrate (DCPD) crystals. In this study, the effects of acidic Ca-P solution concentration (0–600 mmol/L) on the setting reaction and tissue response to β-TCP GC were investigated. The β-TCP GC set upon mixing with its liquid phase, based on the formation of DCPD crystals, which bridged β-TCP granules to one another. Diametral tensile strength of the set β-TCP GC was relatively the same, at approximately 0.6 MPa, when the Ca-P concentration was 20–600 mmol/L. Due to the setting ability, reconstruction of the rat’s calvarial bone defect using β-TCP GC with 20, 200, and 600 mmol/L Ca-P solution was much easier compared to that with β-TCP granules without setting ability. Four weeks after the reconstruction, the amount of new bone was the same, approximately 17% in both β-TCP GC and β-TCP granules groups. Cellular response to β-TCP granules and β-TCP GC using the 20 mmol/L acidic Ca-P solution was almost the same. However, β-TCP GC using the 200 and 600 mmol/L acidic Ca-P solution showed a more severe inflammatory reaction. It is concluded, therefore, that β-TCP GC, using the 20 mmol/L acidic Ca-P solution, is recommended as this concentration allows surgical techniques to be performed easily and provides good mechanical strength, and the similar cellular response to β-TCP granules

    マイクロファイバーを用いた多孔質炭酸アパタイト顆粒の開発とウサギ頭蓋骨における組織学的評価

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    Carbonate apatite (CO3Ap) granules are known to show good osteoconductivity and replaced to new bone. On the other hand, it is well known that a porous structure allows bone tissue to penetrate its pores, and the optimal pore size for bone ingrowth is dependent on the composition and structure of the scaffold material. Therefore, the aim of this study was to fabricate various porous CO3Ap granules through a two-step dissolution-precipitation reaction using CaSO4 as a precursor and 30-, 50-, 120-, and 205-μm diameter microfibers as porogen and to find the optimal pore size of CO3Ap. Porous CO3Ap granules were successfully fabricated with pore size 8.2-18.7% smaller than the size of the original fiber porogen. Two weeks after the reconstruction of rabbit calvarial bone defects using porous CO3Ap granules, the largest amount of mature bone was seen to be formed inside the pores of CO3Ap (120) [porous CO3Ap granules made using 120-μm microfiber] followed by CO3Ap (50) and CO3Ap (30). At 4 and 8 weeks, no statistically significant difference was observed based on the pore size, even though largest amount of mature bone was formed in case of CO3Ap (120). It is concluded, therefore, that the optimal pore size of the CO3Ap is that of CO3Ap (120), which is 85 μm

    チュウネンキ ノ セイカツ ブンミャク モデル サクセイ ノ ココロミ ダンセイ コウレイシャ インタビュー チョウサ ニ モトヅイテ

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    This study aims to develop an integrated model in order to examine the mid-life context, which complies with societal environment and culture of Japan. We compared a model of well-being in old men related to the mid-life context through qualitative research (Ishikawa, 2021a) and a social–ecological model, wherein personal projects are pivotal concepts (Little, 1999, 2017, 2020). Because personal projects are constructive elements of daily life, personal projects analysis enabled conceptualizing the mid-life context based on interviews. Results of the comparison confirmed that middle-age is a central period in life and that it adds the novel “relationships with others” element to the proposed model.研究ノートResearch Not

    A novel high-throughput (HTP) cloning strategy for site-directed designed chimeragenesis and mutation using the Gateway cloning system

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    There is an increasing demand for easy, high-throughput (HTP) methods for protein engineering to support advances in the development of structural biology, bioinformatics and drug design. Here, we describe an N- and C-terminal cloning method utilizing Gateway cloning technology that we have adopted for chimeric and mutant genes production as well as domain shuffling. This method involves only three steps: PCR, in vitro recombination and transformation. All three processes consist of simple handling, mixing and incubation steps. We have characterized this novel HTP method on 96 targets with >90% success. Here, we also discuss an N- and C-terminal cloning method for domain shuffling and a combination of mutation and chimeragenesis with two types of plasmid vectors

    Gender and Japan-Korea Differences in Psychological Characteristics through DIPCA and POMS for All Japan Wheelchair Basketball Atheletes

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    Although previous studies investigating physical performance and biomechanics in wheelchair-bound athletes were reported, few studies have characterized the psychological state of these athletes. This study investigated differences in psychological characteristics among 37 wheelchair-bound athletes (Japanese males, n=11; Japanese females, n=9; Korean males, n=17). All subjects belonged to their own national teams for disabled wheelchair basketball. All subjects completed both the Diagnostic Inventory of Psychological-Competitive Ability for Athletes (DIPCA) and the Profile Of Mood States (POMS). Statictics analysis of DIPCA showed that the psychological competitive abilities in the Japanese males were significantly better than those in the Korean males in this series. However. the scores on POMS did not show significant differences between the Japanese and Korean males, expect for the score for "anger". Neither DIPCA nor POMS showed any significant differences with regard to gender. Above all, we conclude that the psychological differences between Japanese and Koreans reflected the outcomes of international competitions and these there was no gender difference in psychological characteristics
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