Respiratory syncytial virus infection induces higher Toll-like receptor-3 expression and TNF-α production than human metapneumovirus infection

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A role for CD44 in an antigen-induced murine model of pulmonary eosinophilia

Previous studies established that IL-5–producing CD4(+) T cells play a pivotal role in allergic respiratory inflammation. It was also reported that CD4(+) T cells express higher levels of CD44 in the airway than in peripheral blood of patients with allergic respiratory diseases. We have used experimental pulmonary eosinophilia induced in mice by Ascaris suum (Asc) extract to investigate the role of CD44 in the development of allergic respiratory inflammation. Intraperitoneal administration of anti-CD44 mAb prevented both lymphocyte and eosinophil accumulation in the lung. Anti-CD44 mAb also blocked antigen-induced elevation of Th2 cytokines as well as chemokines (CCL11, CCL17) in bronchoalveolar lavage fluid (BALF). Treatment with anti-CD44 mAb inhibited the increased levels of hyaluronic acid (HA) and leukotriene concentrations in BALF that typically result from antigen challenge. Anti-CD44 mAb also blocked antigen-induced airway hyperresponsiveness. An anti-CD44 mAb (IM7) inhibited the HA-binding ability of splenocytes associated with decreased levels of CD44. Soluble CD44 levels in serum were increased in Asc-challenged IM7–treated mice, but not in KM201-treated mice, compared with Asc-challenged rat IgG–treated mice. Ab’s that block CD44-HA binding reduced allergic respiratory inflammation by preventing lymphocyte and eosinophil accumulation in the lung. Thus, CD44 may be critical for development of allergic respiratory inflammation

Recession of Limestone Clifis in Ryukyu Islands

平成14年度～平成16年度科学研究費補助金（基盤研究(C)(2)）研究成果報告書研究概要：本研究は石灰岩が広く分布する琉球列島の島々で,石灰岩が急斜面(崖)をつくる場所,石灰岩台地の縁,石灰岩の海岸をとりあげて,石灰岩の崖・石灰岩の崖の基部にあるノッチの深さ・崖の前面にある崩落ブロックの大きさ・石灰岩の崖の陸側にあるテンションクラックの測量、および撮影年度の異なる空中写真の判読によって、石灰岩の崖の崩落後退による地形変化を定量的に明らかにし,地形変化をもたらす石灰岩の崖の崩落を板状崩落のモデルを用いて力学的に解明しようというのが目的である。沖縄島荒崎海岸,万座毛海岸,宮古島東平安名崎の海食崖,喜界島の段丘崖を研究対象として,岩石の物性に関する室内試験と現地調査を行い,以下の結論を得た. (1)琉球石灰岩の一軸圧縮強度は,調査地点とは無関係に,密度あるいは間隙率と良い相関関係がある. (2)琉球石灰岩の一軸圧縮強度は,寸法効果をもつことが判明し,寸法効果による岩盤強度を推定する式を作成した. (3)片持ちはりのモデルに岩盤強度の推定式を用いて海食崖に関する力学的安定解析を行ったが,より現地の状況に即した安定解析を行うため,海食崖に発達するテンションクラックの深さの影響を考慮した新たなモデルを作成した.このモデルによる安定解析によって,すべての海食崖の崩壊を説明できることがわかった.したがって,琉球石灰岩からなる海食崖の崩壊は,寸法効果による岩石強度とノッチの発達に伴うテンションクラックの深さによって,コントロールされうることがわかった.しかしながら,喜界島の海成段丘に発達する琉球石灰岩からなる段丘崖の崩落条件について,本研究で作成したモデルを適用したところ,うまく説明できなかった.したがって,本研究で作成されたモデルは海食崖の崩壊について有効であることが示唆される.研究概要：Recession of coastal cliffs made of Ryukyu Limestone was studied from the dynamic viewpoint. Several rocky coasts of Okinawa-jima, Miyako-jima and Kikai-jima were selected as the investigated areas. Field measurements were carried out for the cliff height, the depth of notches, the length of fallen blocks and longitudinal wave velocity in rock mass. The cliff height, notch depth and block length range from 2-23 m, 2-9 m and 4-13 m, respectively. Physical and mechanical properties of the cliff material were measured through the laboratory tests. The rock strength drastically decreases with increasing size of specimen, i.e., Ryukyu Limestone has the scale effects in rock strength. Combining the laboratory results of strength reduction due to scale effect and the results of the longitudinal wave velocity obtained from both laboratory and field tests, an equation was derived for estimating of the rock mass strength. Cliff instability was analyzed using a beam analysis model. The stability analysis using the strength of rock mass ignoring scale effects could not well explain cliff failures. Considering tension cracks behind cliff, a new equation for stability analysis was derived. Substituting the estimated rock mass strength and unit weight of cliff material into the equation, we obtain the critical stability lines in cliff height and critical notch depth relationships. Results show that the data from the present cliff profile was plotted in the stable area, while the length and breadth of fallen blocks was plotted on the critical lines. This leads to the conclusion that the analysis of beam failure type, which takes account of the rock mass strength and tension crack, would provide a useful framework for predicting the critical notch depth of cliff made of Ryukyu Limestone.未公開：P.71以降（抜刷論文のため