71 research outputs found

    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

    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

    CT imaging of nasopharyngeal and eustachian tube tonsilloliths

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    Objectives: Nasopharyngeal tonsilloliths (NT) and eustachian tube tonsilloliths (ET) are not as well-known to radiologists as palatine and lingual tonsilloliths. The aim of this investigation was to determine the prevalence and imaging characteristics of NT and ET using CT and panoramic radiographs. Methods: We retrospectively assessed the scans of 2244 patients who underwent consecutive CT and panoramic radiographs of the maxillofacial region. The prevalence, size, number, and position of NT and ET were analysed. Results: NT and ET were detected in 14 (0.6%) and 6 (0.3%) of 2244 patients on CT, respectively, but they were undetectable on panoramic radiographs. No significant difference was found in the prevalence with respect to sex. Although there was also no significant difference in the prevalence among age groups, tonsilloliths were most commonly noted in patients over 40 years old; they appeared as small and round calcified bodies, ranging from 1 to 3 mm in diameter. All NT were found 0 to 3 mm beneath the nasopharyngeal mucosal surface. Conclusions: The prevalence of NT and ET on CT was lower than that of palatine and lingual tonsilloliths. However, since they are encountered more frequently than clinically significant calcifying diseases such as retropharyngeal calcific tendinitis, clinicians should be able to correctly diagnose NT and ET based on their anatomical features

    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

    The Soluble Factor from Oral Cancer Cell Lines Inhibits Interferon-γ Production by OK-432 via the CD40/CD40 Ligand Pathway

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    OK-432 is a potent immunotherapy agent for several types of cancer, including oral cancer. We previously reported that OK-432 treatment can induce the production of high levels of IFN-γ from peripheral blood mononuclear cells (PBMCs). Moreover, the IFN-γ production from PBMCs by OK-432 is impaired by conditioned media (CM) from oral cancer cells. To determine the inhibitory mechanism of IFN-γ production by CM, the genes involved in IFN-γ production was retrieved by cDNA microarray analysis. We found that CD40 played a key role in IFN-γ production via IL-12 production. Although the expression levels of CD40 were upregulated by OK-432 treatment in PBMCs, CM inhibited OK-432-induced CD40 expression. These findings suggest that uncertain soluble factor(s) in CM may suppress IFN-γ production via the CD40/CD40L–IL-12 axis in PBMCs.(1) Background: OK-432 is a penicillin-killed, lyophilized formulation of a low-toxicity strain (Su) of Streptococcus pyogenes (Group A). It is a potent immunotherapy agent for several types of cancer, including oral cancer. We previously showed that (i) OK-432 treatment induces a high amount of IFN-γ production from peripheral blood mononuclear cells (PBMCs), and (ii) conditioned medium (CM) from oral cancer cells suppresses both the IFN-γ production and cytotoxic activity of PBMCs driven by OK-432. The aim of this study was to determine the inhibitory mechanism of OK-432-induced IFN-γ production from PBMCs by CM. (2) Methods: We performed cDNA microarray analysis, quantitative RT-PCR, and ELISA to reveal the inhibitory mechanism of CM. (3) Results: We found that CD40 plays a key role in IFN-γ production via IL-12 production. Although OK-432 treatment upregulated the expression levels of the IL-12p40, p35, and CD40 genes, CM from oral cancer cells downregulate these genes. The amount of IFN-γ production by OK-432 treatment was decreased by an anti-CD40 neutralizing antibody. (4) Conclusions: Our study suggests that uncertain soluble factor(s) produced from oral cancer cells may inhibit IFN-γ production from PBMCs via suppressing the CD40/CD40L–IL-12 axis

    ジョシガクセイ ノ BMI オヨビ シンタイ ソセイ ト ショクモツ セッシュ ト ノ カンレン

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     本研究は、女子学生の体格的特徴を明らかにするために、本学一年生を対象としてBMI と身体組成、食物摂取について調査し、これらがどのように関連するか検討した。 対象者157名の体脂肪率の平均は28.0±6.4%であり、BMI普通体重群のうち体脂肪率が28.0%以上の過剰群は43.4%を占めた。 体脂肪率18.0%以上25.0%未満の普通低値群と、28.0%以上の過剰群において対応のないt検定を行ったところ、ほとんどの食品群において普通低値群の方が多く摂取しており、有意差はみられなかったものの、エネルギー摂取量は普通低値群が1,861±857kcalと過剰群の1,609±480kcalより高かった。さらに体重1kg あたりの基礎代謝量は過剰群では20.9±1.7kcalと、普通低値群の24.6±1.0kcalと大きく異なった。 過剰群では食事の摂取量が少ないものの、基礎代謝量も低く、また日常生活の中での身体活動は低強度であるため、運動強度に留意した運動指導を行う必要があると考えられた

    Carbon Ion Radiotherapy for Early Breast Cancer

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    Introduction :Breast cancer is a major health problem for women in all over the world. The standard care for early stage breast cancer is breast conserving therapy which consists of conservative surgery and fractionated whole breast irradiation. Fractionated irradiation takes more than 5 weeks and is a burden to patients. Accelerated Partial Breast Irradiation (APBI) is an alternative to fractionated whole breast irradiation in patients with low risk tumor. Objective :We are about to conduct a clinical trial of radical APBI without surgery using carbon iron irradiation for patients with low risk tumor. A candidate of carbon ion treatment is T1N0M0, estrogen receptor (ER) positive, HER2 negative, invasive ductal carcinoma or other favorable type, without extensive intraductal component, lymph vascular space invasion, and tumor located more than 5 mm from skin. Methodology :Carbon ion beams provide superior physical dose distribution because of their finite range in the target tissue, and they possess a biological advantage due to their high relative biological effectiveness in the Bragg peak. Since 1994, our institute has treated more than 7,000 cases of various malignancies. We plan to use dose escalation of 12 GyE, 13.2 GyE and 15 GyE per fraction and 4 fractions in one week for breast tumor. Results :We finalized the technical preparation and ethical approval. Conclusion :We will start clinical trial from April 2013. Just a four fractions of carbon ion radiotherapy could have a potential to be an alternative of surgery and conventional radiotherapy.29th International Congress of the Medical Women\u27s International Associatio
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