Hypertension, a risk factor for aortic valve stenosis, increases transvalvular load and can elicit extracellular matrix (ECM) remodeling. Elevated cyclic pressure and the vasoactive agent angiotensin II (Ang II) both promote collagen synthesis, an early hallmark of aortic sclerosis. It was hypothesized that increased collagen production induced by elevated pressure conditions or the presence of Ang II would affect the mechanical properties of leaflet tissue by decreasing extensibility. Porcine aortic valve leaflets were exposed to pressure conditions of increasing magnitude with and without Ang II. Biaxial mechanical testing was performed to determine peak stretch. Collagen content was determined using a quantitative dye-binding method. The results demonstrated Ang II and elevated pressure decrease the extensibility of leaflet tissue and increase the collagen content in the ECM. In conclusion, the results demonstrated that both elevated pressure and Ang II play a role in altering the biomechanical properties of aortic valve leaflets.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24458号 / 理博第4957号 / 新制||理||1708(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 高橋 淑子, 准教授 佐藤 ゆたか, 教授 中務 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Utilizing the polyvinyl sponge-implant model in the rabbit we have previously demonstrated modification in low density lipoproteins (LDL) of interstitial tissue fluid obtained in association with a cellular inflammatory response. In order to examine the interaction between the inflammatory response and lipoproteins from hypercholesterolemic rabbits, 30 male, New Zealand White rabbits were fed standard chow supplemented with 0.5% cholesterol for 4 weeks prior to sponge implantation. Lipoproteins were prepared from interstitial inflammatory fluid (IF) as well as homologous whole plasma (WP). Total IF cholesterol was positively correlated with plasma cholesterol (459 ± 43 vs. 1485 ± 130 mg/dl, X ± SEM, r = 0.81, P < 0.01). Distribution of lipoproteins in IF was similar to WP in both particle size and density. Beta-migrating VLDL were the predominant particles in both WP and IF, containing 43.7 ± 3.4 and 42.2 ± 5.1% of WP and IF cholesterol, respectively. IF-VLDL were similar to WP-VLDL in lipid and apoprotein composition, morphology and particle size distribution. We conclude from these data that the observed dramatic alterations in lipoprotein distribution in response to a dietary cholesterol challenge in rabbit plasma is essentially unaltered in interstitial inflammatory fluid obtained from these animals.

At Huntington Beach, SC meiofauna distribution was investigated. The purpose of the study was to determine tardigrade species present and any significant differences in the distribution pattern. Meiofauna were analyzed to determine if there were significant differences in their distribution patterns in relation to abiotic variables. Cores were taken in the intertidal zone along three elevations. Each core was divided into depth samples and was processed to remove meiofauna. Each taxon (>1500 specimens) and tardigrades was statistically analyzed using three-way ANOVA to compare distribution patterns. There were eighteen taxa identified and an estimated 330,338 specimens. The seven dominant taxa were Nematoda, Copepoda, Oligochaeta, Mystacocarida, Sarcomastigophora, Halacaroidea, and Turbellaria. The community and each taxon demonstrated one or more significant differences in their distribution pattern. Tardigrada had 326 specimens collected and 300 identified to species in five genera. Elevation was a source of significant variation for tardigrades.

The interstitial concentration and temperature dependence of the diffusion coefficient ratio D12/D11 in ternary austenites containing silicon or manganese has been experimentally determined using diffusion couples based on the concept of "transient equilibrium". The results are compared with values predicted theoretically from statistical and thermodynamic considerations. </p> <p> The kinetics of the growth of proeutectoid ferrite in binary and ternary austenites have been determined, using two-phase diffusion couples. The results are consistent with the premise that carbon diffusion controls the rate of interface migration. It is demonstrated, theoretically and experimentally, that the ternary results fall into two classes - one in which local equilibrium may be assumed, and one in which "constrained local equilibrium" may be postulated. / Thesis / Doctor of Philosophy (PhD)

No description available.

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第22752号 / 薬科博第126号 / 新制||薬科||14(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 金子 周司, 教授 土居 雅夫, 教授 竹島 浩 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

No description available.

No description available.

No description available.