Functional role of HSP47 in the periodontal ligamentsubjected to occlusal overload in mice

松本歯科大学大学院歯学独立研究科博士（歯学）学位申請論文要旨 ; 大学院歯学独立研究科　健康増進口腔科学講座（主指導教員：藤井　健男　教授

Strain distribution analysis of sputter-formed strained Si by tip-enhanced Raman spectroscopy

Simultaneous nanometer-scale measurements of the strain and surface undulation distributions of strained Si (s-Si) layers on strain-relief quadruple-Si1-xGex-layer buffers, using a combined atomic force microscopy (AFM) and tip-enhanced Raman spectroscopy (TERS) system, clarify that an s-Si sample formed by our previously proposed sputter epitaxy method has a smoother and more uniformly strained surface than an s-Si sample formed by gas-source molecular beam epitaxy. The TERS analyses suggest that the compositional fluctuation of the underlying Si1-xGex buffer layer is largely related to the weak s-Si strain fluctuation of the sputtered sampl

CT画像を用いて算出したHip Structural Analysis(HSA)指標の検討

骨粗鬆症に伴う脆弱性骨折を起こすか否かは,骨量,骨構造,骨の石灰化,ダメージの蓄積および骨代謝などに依存するとされているが,近年,骨量測定に臨床で広く用いられているDXA装置に大腿骨近位部の構造力学的解析が可能なHip Structural Analysis (HSA) のプログラムが組み込まれ,骨強度の評価に用いられている.そこで我々は,CT画像からHSA指標の算出が可能か否か,また,その手法による指標の計算精度について,DXA装置で得られた指標と比較することによって検討した.その結果,CT画像からHSA指標の算出は可能であったが,その計算精度に若干の問題があり,撮影時の整位および計算位置の解剖学的なズレ等を補正する必要があることがわかった

Comparative Studies of Values of Bone Mineral Density Measured with Different Photon Absorptiometries : A Preliminary Report

In order to compare values of bone mineral density measured with various photon absorptiometries, fundamental studies, using four different types of phantoms were performed in four instruments. The QDR-1000 (dual energy X-ray absorptiometry, DEXA) and Dualomex HC-1 (dual photon absorptiometry) were employed for the determination of bone mineral of a lumbar phantom and a cylindrical phantom, and the DCS-600 (DEXA) and Bone Densitometer (single photon absorptiometry) were used for the determination of bone mineral of a rectangular phantom and a ring phantom. The results indicate that the methodology for identification of the bone edge, which is necessary to calculate bone area or bone width, and the bone mineral per unit volume, which is defined as the line bone mineral content per cross-secional area, differ with the instruments used. Furthermore, the bone mineral per unit volume depends on the bone shape of the measured objects. Therefore, it seems taht the cross calibration of bone mineral density between instruments using phantoms is limited and in vivo investigation will be required in the future

Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice

We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship’s lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload

Microsoft Excelにおける2次元フーリエ変換を用いた画像処理法の構築

Microsoft Excelを用いて2次元高速フーリエ変換を行い,空間周波数領域で画像処理する方法の構築を目的とした.検討には,処理対象画像として胸部骨シンチグラム像を,解析アプリケーションソフトにはMicrosoft Excel 2007とImage Jをそれぞれ用いた.なお,Microsoft Excelでの高速フーリエ変換は,処理時間を短縮するためマクロを構築した.その結果,Microsoft Excelでの処理画像は,核医学のデータ処理専用装置のそれとの間に殆ど差が認められなかった.これにより,我々が構築したMicrosoft Excelを用いた画像処理法は,十分に使用可能なことが証明された

実験的咬合性外傷による歯根膜の細胞動態

Using a model of experimental occlusal trauma in mice, we investigated cytological kinetics of periodontal ligament by means of histopathological, immunohistochemical, and photographical analysis methods. At furcation areas of molar teeth in the experimental group on day 4, the increase of cells in periodontal ligament was seen. The cells with a round-shaped nucleus were deeply stained in the hematoxylin-eosin. Ki67 positive nuclei showed a prominent increase in the experimental groups on days 4 and 7. Green Fluorescent Protein (GFP) positivity also revealed cell movement, but this action was slightly slow compared to Ki67 staining specimens. It was indicated that the homeostasis is mechanism of periodontal ligament receiving the excessive occlusal loading was promoted by osteoclasts and macrophages from bone-marrow-derived cells migrated to the periodontal ligament. The remodeling of periodontal ligament with the acceleration of cell growth was evoked from the experiment for the group on day 4 and after day 7. The findings suggested that periodontal ligament at furcation areas of molar teeth in occlusal trauma model was recovered by using both of the cells in situ and the bone-marrow-derived cells.2015博士（歯学）松本歯科大