• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 321
  • 274
  • 97
  • 51
  • 24
  • 9
  • 9
  • 8
  • 7
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • Tagged with
  • 940
  • 196
  • 158
  • 125
  • 122
  • 99
  • 91
  • 91
  • 89
  • 89
  • 85
  • 84
  • 74
  • 71
  • 65
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Dietary calcium and cation-anion difference influences calcium status and bone remodeling in exercising and sedentary Arabian horses

Porr, Cheryl Ann 06 June 2008 (has links)
Diet and exercise are two manageable factors that affect bone remodeling. Experiments were designed to test the hypothesis that bone density and calcium status would be affected by conditioning and deconditioning, and by dietary Ca and cationanion difference (DCAD). In experiment one, 12 Arabian horses were conditioned for 12 wk on a high speed equine treadmill. Diets were designated LH, which contained low Ca (.35%)-high Cl (.6%), LL, low Ca-low Cl (no added Cl), HH, high Ca (.7%)- high Cl, and HL, high Ca-low Cl. Data were collected while horses were at rest every 21 d. Serum and plasma were analyzed for total and ionized Ca, P, Mg, Cl, total protein, albumin, parathyroid hormone (PTH), osteocalcin, and hydroxyproline. Radiographs of the left third metacarpal bone were taken. An aluminum step wedge exposed simultaneously was used as a reference standard for estimating bone mineral content (BMC) with an image analysis program. Bone measurements, including BMC, bone and medullary width, and cortical area, were taken in the proximal diaphyseal and proximal metaphyseal area. Bone variables increased with training and with high Ca diets as compared to horses fed low Ca diets. Serum Ca decreased and serum PTH increased with training. Hydroxyproline was unchanged in horses fed the low Ca diets and decreased in horses fed the high Ca diets. Serum osteocalcin increased then decreased with training. The high Ca diet appeared to facilitate bone remodeling in response to training, but dietary Cl, hence DCAD, had no effect. In experiment two, 11 conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. They were walked on a mechanical walker in two 30 min sessions 7 d/wk. Diets were designated LC (.35% Ca) and HC (.7% Ca). Data collection and analysis were identical to those in experiment one. Bone variables decreased with deconditioning but were unaffected by dietary Ca. Serum Ca increased with deconditioning and was greater in horses fed the HC diet, but PTH did not change. Horses fed the HC diet had greater serum osteocalcin, which decreased with deconditioning. Dietary Ca influenced bone remodeling in response to training, but did not have an effect on bone response to deconditioning. Loss of BMC during 12 wk of stall confinement may predispose horses to skeletal injuries when training is resumed. / Ph. D.
212

Epigenetic regulation of osteoblast differentiation

Najafova, Zeynab 09 August 2016 (has links)
No description available.
213

Avaliação da gordura epicárdica e sua influência no remodelamento cardíaco de obesos mórbidos submetidos à cirurgia bariátrica / Epicardial fat evaluation and its influence on cardiac remodeling of morbid obese subjects submitted to bariatric surgery

Cardoso, Acácio Fernandes 03 July 2018 (has links)
A gordura epicárdica é biologicamente ativa e sua espessura nos obesos é aumentada. A repercussão da gordura epicárdica sobre o remodelamento cardíaco ainda não está completamente elucidada. No presente estudo, foi avaliada a gordura epicárdica e sua influência no remodelamento cardíaco de obesos mórbidos, antes e após a cirurgia bariátrica. Métodos: No Hospital das Clínicas da Universidade de São Paulo, foram recrutados de forma prospectiva 20 obesos mórbidos sem outras comorbidades e 20 controles. Os participantes realizaram avaliação clínica e laboratorial, medida da duração da onda P no ECG e ecocardiograma transtorácico. O grupo de obesos repetiu essa avaliação 12 meses após a cirurgia bariátrica. A medida da gordura epicárdica foi feita pelo ecocardiograma. Para comparar as variáveis contínuas, foram utilizados os testes t de Student (não pareado e pareado), de Mann-Whitney ou de Wilcoxson. Para definir correlação entre as variáveis lineares, foi utilizado o coeficiente de correlação de Pearson. Para definir a associação entre variáveis categóricas, foi usado o teste exato de Fisher. Para avaliar a associação entre variáveis dependentes e independentes, foi realizada uma análise de regressão múltipla. Os dados foram examinados no software R. Um valor de p abaixo de 0,05 foi considerado significativo. Resultados: No préoperatório, foram observados níveis elevados de proteína C reativa, uma maior duração da onda P, da massa ventricular e do diâmetro do átrio esquerdo nos obesos em relação aos controles (p < 0,05). Uma menor fração de ejeção do ventrículo esquerdo foi observada no grupo de obesos (p < 0,05). A gordura epicárdica foi maior nos obesos (p < 0,01). Uma correlação positiva foi encontrada entre a gordura epicárdica, a duração da onda P (r=0,70; p < 0,01), o diâmetro do átrio esquerdo (r=0,67; p < 0,01) e a massa ventricular (r=0,58; p < 0,01). Uma correlação inversa foi observada entre a gordura epicárdica e a fração de ejeção do ventrículo esquerdo (r=- 0,52; p < 0,01). Na análise de regressão múltipla, a gordura epicárdica permaneceu correlacionada com a duração da onda P, o diâmetro do átrio esquerdo e a fração de ejeção do ventrículo esquerdo (p < 0,05). Em 60% dos obesos, foi identificada alguma alteração na geometria ventricular. Uma associação entre a espessura da gordura epicárdica maior ou igual a 3,7 mm e a presença de remodelamento ventricular geométrico foi demonstrada (p=0,03). No pós-operatório, observou-se uma redução do índice de massa corporal, da proteína C reativa e da gordura epicárdica (p < 0,01). Uma redução da duração da onda P e um aumento da fração de ejeção do ventrículo esquerdo também foram observados (p < 0,01). Na análise de regressão múltipla esses achados permaneceram correlacionados à redução da gordura epicárdica (p < 0,05), independente da variação do índice de massa corporal e da proteína C reativa. Conclusões: Em obesos mórbidos sem outras comorbidades, a gordura epicárdica foi associada a um aumento da duração da onda P, do diâmetro do átrio esquerdo e da massa ventricular, além de uma menor fração de ejeção do ventrículo esquerdo. A espessura da gordura epicárdica igual ou acima de 3,7 mm foi associada a alterações do remodelamento ventricular. A redução da gordura epicárdica após a cirurgia bariátrica foi associada com a redução da duração da onda P e o aumento da fração de ejeção do ventrículo esquerdo, independente da variação do índice de massa corporal e da proteína C reativa / Epicardial fat is biologically active and its thickness is increased in obese subjects. The effects of epicardial fat on cardiac remodeling are still not fully understood. In the present study we evaluated epicardial fat and its influence on cardiac remodeling of morbidly obese, before and after bariatric surgery. Methods: We prospectively recruited 20 morbid obese subjects without other comorbidities and 20 control subjects at Hospital das Clínicas, Universidade de São Paulo. Participants underwent clinical and laboratory assessment, measure of P-wave duration on ECG and transthoracic echocardiogram. The obese group repeated this evaluation 12 months after the bariatric surgery. To compare continuous variables, we used t Student test (paired and nonpaired), Mann-Whitney and Wilcoxson tests. To define the correlation between linear variables we used Pearson correlation coefficient. To define the association between categorical variables we used Fisher exact test. A multiple regression analysis was performed to assess the association between dependent and independent variables. Data were analyzed by software R. A p value below 0.05 was considered statistically significant. Results: Preoperatively, we observed high levels of C-reactive protein, longer P-wave duration, larger ventricular mass and left atrial diameter in obese subjects compared to the controls (p < 0.05). Lower left ventricle ejection fraction was observed in the obese group (p < 0.05). Epicardial fat was higher among obese subjects (p < 0.01). A positive correlation was found between epicardial fat and P-wave duration (r=0.70; p < 0.01), left atrial diameter (r=0.67; p < 0.01), and ventricular mass (r=0.58; p < 0.01). An inverse correlation was observed between epicardial fat and left ventricle ejection fraction (r=-0.52; p < 0.01). In the multiple regression analysis, epicardial fat remained correlated with P-wave duration, left atrial diameter and left ventricle ejection fraction (p < 0.05). In 60% of the obese subjects, there was some abnormality in ventricular geometry. We showed association between thickness of epicardial fat equal to or higher than 3.7 mm and presence of geometric ventricular remodeling (p=0.03). Postoperatively, we observed reduction in body mass index, C-reactive protein and epicardial fat (p < 0.01). Reduction in P-wave duration and an increase in left ventricle ejection fraction were also observed (p < 0.01). In the multiple regression analysis, these findings were correlated with reduction in epicardial fat (p < 0.05), regardless of the variation in body mass index and C-reactive protein. Conclusion: In morbid obese subjects without other comorbidities, epicardial fat was associated with increase in P-wave duration, left atrial diameter and ventricular mass, in addition to smaller left ventricle ejection fraction. Epicardial fat thickness equal to or greater than 3.7 mm was associated with abnormalities in ventricular remodeling. Reduction of epicardial fat after bariatric surgery was associated with reduction of P-wave duration and increase in left ventricle ejection fraction, regardless of the variation in body mass index and C-reactive protein
214

Tectonics in police housing: refurbishing of Cheung Sha Wan police housing.

January 2005 (has links)
Tse Hoi Man Tiffany. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2004-2005, design report." / Chapter 0. --- Introduction / Chapter 0.1 --- Background / Chapter 0.2 --- Purpose / Chapter 0.3 --- Content / Chapter Part I --- Research Study / Chapter 1. --- Background / Chapter 1.1 --- 6 Police Housing in Hong Kong / Chapter 1.2 --- Timeline of evolution of Street in the air / Chapter 2. --- Comparison Study / Chapter 2.1 --- Building / Chapter 2.1.1 --- Immersble Villa / Chapter 2.1.2 --- Unite d'Habition / Chapter 2.1.3 --- Golden Lane / Chapter 2.1.4 --- Park Hill / Chapter 2.1.5 --- Robin Hood Garden / Chapter 2.1.6 --- Police Housing . Ho Man Tin / Chapter 2.1.7 --- Police Housing . Cheung Sha Wan / Chapter 2.1.8 --- Police Housing . North Point / Chapter 2.2 --- Issue / Chapter 2.2.1 --- Site / Chapter 2.2.2 --- Circulation (pubic) / Chapter 2.2.3 --- Circulation (private) / Chapter 2.2.4 --- Access to Unit / Chapter 2.2.5 --- Street Design / Chapter 2.2.6 --- Structure and Facade Relationship / Chapter 2.2.7 --- Unit Organization and Unit Layout / Chapter Part II --- Design / Chapter 1. --- Introduction / Chapter 1.1 --- Cheung Sha Wan Police Housing as experiment / Chapter 2. --- Programme / Chapter 2.1 --- Research on current police hostel / Chapter 2.1.1 --- Shun Lee Disciplined Services Quarters / Chapter 2.1.2 --- Sau Mou Ping Disciplined Services Quarters / Chapter 2.2 --- Programme for the modification of existing police hostel / Chapter 2.2.1 --- Combination of units / Chapter 3. --- Conceptual Study / Chapter 3.1 --- Transformation of stair core / Chapter 3.1.1 --- Exploration on unit combination with different circulation approaches / Chapter 3.1.2 --- Public vs. private circulation / Chapter 3.1.3 --- Final version / Chapter 4. --- Final Design / Chapter 4.1 --- Block Level / Chapter 4.2 --- Flat Level
215

Relação entre biomarcadores inflamatórios, de adesão celular, de estresse oxidativo, de lesão endotelial, remodelamento tecidual e vascular e os diferentes estágios da doença venosa crônica primária (classes clínicas CEAP C0a, C2, C3, C4) / Relationship between biomarkers of inflammation, cell adhesion, oxidative stress, endothelial cell damage, vascular and tissue remodeling and the different stages of primary chronic venous disease (CEAP clinical classes C0a, C2, C3, C4)

Maria das Graças Coelho de Souza 20 August 2013 (has links)
A doença venosa crônica (DVC) é uma desordem complexa que compreende sinais e sintomas que variam das telangiectasias às úlceras ativas. A DVC é classificada de acordo com aspectos clínicos, etiológicos, anatômicos e fisiopatológicos (CEAP) em sete classes variando de C0 à C6. A principal causa da DVC é a hipertensão venosa que altera o fluxo venoso e, consequentemente, a força de cisalhamento que induz alterações fenotípicas nas células endoteliais que passam a expressar mediadores pró-inflamatórios e pró-trombóticos, que levam à adesão de leucócitos, ao aumento do estresse oxidativo, da permeabilidade vascular e do dano endotelial e ao remodelamento tecidual e vascular.Em virtude dos inúmeros mecanismos e da diversidade de moléculas envolvidas na patogênese e progressão da DVC, é essencial conhecer a interação entre elas e também saber quais são as moléculas (biomarcadores) que se correlacionam positivamente ou negativamente com a gravidade da doença. Foram avaliados os níveis de Interleucina-6 (IL-6), sL-selectina, sE-selectina, sP-selectina, molécula de adesão intercelular-1solúvel (sICAM-1), molécula de adesão das células vasculares-1 solúvel (sVCAM-1), ativador tecidual do plasminogênio (tPA), atividade do inibidor do ativador do plasminogênio-1 (PAI-1), trombomodulina solúvel (sTM), fator de von Willebrand (vWF), metaloproteinase de matriz (MMP)-2, MMP-3, MMP-9, inibidor tecidual das MMPs -1 (TIMP-1), angiopoietina-1 e -2, sTie-2 e s-Endoglina e fator de crescimento do endotélio vascular (VEGF) no sangue coletado da veia braquial de 173 mulheres com DVC primária divididas em grupos C2, C3, C4 e C4 menopausadas (C4m) e de 18 voluntárias saudáveis (grupo C0a). Foram também analisados os níveis urinários de ent-prostaglandina F2&#945; nesses grupos. Não foram encontradas diferenças estatisticamente significativas com relação às concentrações sanguíneas e urinárias de sE-selectina, sP-selectina, sICAM-1, atividade de PAI-1, MMP-3, razão TIMP-1/MMP-3, angiopoietin-2, razão angiopoietina-1/angiopoietina-2, s-Endoglina e ent-prostaglandina F2&#945; entre os grupos estudados, possivelmente devido à alta variabilidade na concentração desses biomarcadores entre as participantes do mesmo grupo. Entretanto, as concentrações sanguíneas de IL-6 sL-selectina, sVCAM-1, tPA, vWF, sTM, MMP2, MMP-9, TIMP-1, razão TIMP-1/MMP-2, razão TIMP-1/MMP-9, angiopoietina-1 e VEGF foram estatisticamente diferentes entre os grupos. Não foi identificado nenhum biomarcador que se correlacionasse diretamente ou inversamente com a progressão da DVC, provavelmente devido à diversidade de fatores envolvidos e à complexa interação entre eles durante o curso da doença. / Chronic Venous Disease (CVD) is a complex disorder, which encompasses signs and symptoms that vary from telangiectasias to active ulcers. The CVD is classified according Clinical, Etiologic, Anatomical and Pathophysiological (CEAP) aspects into seven classes varying from C0 to C6. The main cause of CVD is venous hypertension, which alters venous flow and consequently, shear stress. Abnormal shear stress induces phenotypic changes in endothelial cells that start to express pro-inflammatory and pro-thrombotic mediators that lead to leukocyte adhesion, oxidative stress, increased vascular permeability and endothelial cell damage and tissue and vascular remodeling. Due to several mechanisms and the diversity of molecules involved in the pathogenesis and progression of CVD, is essential to know the interplay between them and which are the molecules (biomarkers) that correlate positively and negatively with the severity of the disease. We investigated the levels of interleukin-6 (IL-6), sL-selectin, sE-selectin, sP-selectin, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) activity, soluble thrombomodulin (sTM), von Willebrand factor (vWf), matrix metalloproteinase (MMP)-2, MMP-3, MMP-9, tissue inhibitor of metaloproteinases-1 (TIMP-1), angiopoietin-1 and -2, sTie-2, s-Endoglin, vascular endothelial growth factor (VEGF) in the blood taken from the brachial vein of 173 patients with primary CVD divided into C2, C3, C4 and menopaused C4 (C4m) groups and 18 healthy volunteers (C0a group).We also investigated the urinary levels of ent-prostaglandin F2&#945; in these groups. There was no statistically significant difference between groups with respect to blood or urinary levels of sE-selectin, sP-selectin, sICAM-1, PAI-1 activity, MMP-3, TIMP-1/MMP-3 ratio, angiopoietin-2, angiopoietin-1/angiopoietin-2 ratio, s-Endoglin and ent-prostaglandin F2&#945;, likely due to the high variability of these biomarkers concentration among participants within the same group. However, blood levels of IL-6, sL-selectin, sVCAM-1, tPA, vWF, sTM, MMP-2, MMP-9, TIMP-1, TIMP-1/MMP-2 ratio, TIMP-1/MMP-9 ratio, angiopoietin-1 and VEGF were statistically different between groups. It was not identified any biomarker that correlated directly or inversely with the progression of CVD, probably due to the diversity of factors involved and the complex interplay between them in the course of the disease.
216

Avaliação da gordura epicárdica e sua influência no remodelamento cardíaco de obesos mórbidos submetidos à cirurgia bariátrica / Epicardial fat evaluation and its influence on cardiac remodeling of morbid obese subjects submitted to bariatric surgery

Acácio Fernandes Cardoso 03 July 2018 (has links)
A gordura epicárdica é biologicamente ativa e sua espessura nos obesos é aumentada. A repercussão da gordura epicárdica sobre o remodelamento cardíaco ainda não está completamente elucidada. No presente estudo, foi avaliada a gordura epicárdica e sua influência no remodelamento cardíaco de obesos mórbidos, antes e após a cirurgia bariátrica. Métodos: No Hospital das Clínicas da Universidade de São Paulo, foram recrutados de forma prospectiva 20 obesos mórbidos sem outras comorbidades e 20 controles. Os participantes realizaram avaliação clínica e laboratorial, medida da duração da onda P no ECG e ecocardiograma transtorácico. O grupo de obesos repetiu essa avaliação 12 meses após a cirurgia bariátrica. A medida da gordura epicárdica foi feita pelo ecocardiograma. Para comparar as variáveis contínuas, foram utilizados os testes t de Student (não pareado e pareado), de Mann-Whitney ou de Wilcoxson. Para definir correlação entre as variáveis lineares, foi utilizado o coeficiente de correlação de Pearson. Para definir a associação entre variáveis categóricas, foi usado o teste exato de Fisher. Para avaliar a associação entre variáveis dependentes e independentes, foi realizada uma análise de regressão múltipla. Os dados foram examinados no software R. Um valor de p abaixo de 0,05 foi considerado significativo. Resultados: No préoperatório, foram observados níveis elevados de proteína C reativa, uma maior duração da onda P, da massa ventricular e do diâmetro do átrio esquerdo nos obesos em relação aos controles (p < 0,05). Uma menor fração de ejeção do ventrículo esquerdo foi observada no grupo de obesos (p < 0,05). A gordura epicárdica foi maior nos obesos (p < 0,01). Uma correlação positiva foi encontrada entre a gordura epicárdica, a duração da onda P (r=0,70; p < 0,01), o diâmetro do átrio esquerdo (r=0,67; p < 0,01) e a massa ventricular (r=0,58; p < 0,01). Uma correlação inversa foi observada entre a gordura epicárdica e a fração de ejeção do ventrículo esquerdo (r=- 0,52; p < 0,01). Na análise de regressão múltipla, a gordura epicárdica permaneceu correlacionada com a duração da onda P, o diâmetro do átrio esquerdo e a fração de ejeção do ventrículo esquerdo (p < 0,05). Em 60% dos obesos, foi identificada alguma alteração na geometria ventricular. Uma associação entre a espessura da gordura epicárdica maior ou igual a 3,7 mm e a presença de remodelamento ventricular geométrico foi demonstrada (p=0,03). No pós-operatório, observou-se uma redução do índice de massa corporal, da proteína C reativa e da gordura epicárdica (p < 0,01). Uma redução da duração da onda P e um aumento da fração de ejeção do ventrículo esquerdo também foram observados (p < 0,01). Na análise de regressão múltipla esses achados permaneceram correlacionados à redução da gordura epicárdica (p < 0,05), independente da variação do índice de massa corporal e da proteína C reativa. Conclusões: Em obesos mórbidos sem outras comorbidades, a gordura epicárdica foi associada a um aumento da duração da onda P, do diâmetro do átrio esquerdo e da massa ventricular, além de uma menor fração de ejeção do ventrículo esquerdo. A espessura da gordura epicárdica igual ou acima de 3,7 mm foi associada a alterações do remodelamento ventricular. A redução da gordura epicárdica após a cirurgia bariátrica foi associada com a redução da duração da onda P e o aumento da fração de ejeção do ventrículo esquerdo, independente da variação do índice de massa corporal e da proteína C reativa / Epicardial fat is biologically active and its thickness is increased in obese subjects. The effects of epicardial fat on cardiac remodeling are still not fully understood. In the present study we evaluated epicardial fat and its influence on cardiac remodeling of morbidly obese, before and after bariatric surgery. Methods: We prospectively recruited 20 morbid obese subjects without other comorbidities and 20 control subjects at Hospital das Clínicas, Universidade de São Paulo. Participants underwent clinical and laboratory assessment, measure of P-wave duration on ECG and transthoracic echocardiogram. The obese group repeated this evaluation 12 months after the bariatric surgery. To compare continuous variables, we used t Student test (paired and nonpaired), Mann-Whitney and Wilcoxson tests. To define the correlation between linear variables we used Pearson correlation coefficient. To define the association between categorical variables we used Fisher exact test. A multiple regression analysis was performed to assess the association between dependent and independent variables. Data were analyzed by software R. A p value below 0.05 was considered statistically significant. Results: Preoperatively, we observed high levels of C-reactive protein, longer P-wave duration, larger ventricular mass and left atrial diameter in obese subjects compared to the controls (p < 0.05). Lower left ventricle ejection fraction was observed in the obese group (p < 0.05). Epicardial fat was higher among obese subjects (p < 0.01). A positive correlation was found between epicardial fat and P-wave duration (r=0.70; p < 0.01), left atrial diameter (r=0.67; p < 0.01), and ventricular mass (r=0.58; p < 0.01). An inverse correlation was observed between epicardial fat and left ventricle ejection fraction (r=-0.52; p < 0.01). In the multiple regression analysis, epicardial fat remained correlated with P-wave duration, left atrial diameter and left ventricle ejection fraction (p < 0.05). In 60% of the obese subjects, there was some abnormality in ventricular geometry. We showed association between thickness of epicardial fat equal to or higher than 3.7 mm and presence of geometric ventricular remodeling (p=0.03). Postoperatively, we observed reduction in body mass index, C-reactive protein and epicardial fat (p < 0.01). Reduction in P-wave duration and an increase in left ventricle ejection fraction were also observed (p < 0.01). In the multiple regression analysis, these findings were correlated with reduction in epicardial fat (p < 0.05), regardless of the variation in body mass index and C-reactive protein. Conclusion: In morbid obese subjects without other comorbidities, epicardial fat was associated with increase in P-wave duration, left atrial diameter and ventricular mass, in addition to smaller left ventricle ejection fraction. Epicardial fat thickness equal to or greater than 3.7 mm was associated with abnormalities in ventricular remodeling. Reduction of epicardial fat after bariatric surgery was associated with reduction of P-wave duration and increase in left ventricle ejection fraction, regardless of the variation in body mass index and C-reactive protein
217

The role of Smad7 in regulating bone remodeling, osteoporosis and BM-MSCs differentiation.

January 2014 (has links)
Smad7作為轉化生長因數-β信號通路中的負性調節因子為人所知,異常的Smad7表達通常會引發癌症及組織纖維化等疾病。而目前對於其在骨重建及其相關疾病中的作用尚未有研究。本研究利用Smad7部分敲除小鼠來探索Smad7在骨重建,骨質疏鬆以及間充質幹細胞分化等方面的作用。 / 本研究所用的Smad7部分敲除小鼠模型來源於已有報導過的Smad7ΔE1(KO)小鼠。該小鼠體內Smad7基因組外顯子I的翻譯區被替換,導致部分蛋白失及其功能破壞。研究結果表明,KO小鼠在6、12、24周齡時股骨遠端幹骺端均有不同程度下降的骨小梁數目、厚度,骨礦化率,骨密度,骨體積分數,及其上升的骨小梁間隙和破骨細胞表面。骨髓來源間充質幹細胞的多向分化實驗表明,KO組呈現出抑制性的成骨能力,表現為鈣結節形成減少,鹼性磷酸酶活性下降,早晚期成骨標記基因表達下降。該組亦表現出促進性的成脂能力,有較多及較早的脂滴形成,成脂標記基因表達上升。而對於骨髓來源巨噬細胞的體外破骨誘導實驗表明,KO組有更多且更大的破骨細胞形成,較大的骨吸收面積,以及上升的破骨標記基因表達。卵巢切除小鼠模型的研究表明,術後4、8、16周,KO组的股骨遠端幹骺端对比野生组有更大程度下降的骨形态学参数,以及明顯升高的破骨細胞融合標記蛋白的表達。體外實驗表明KO组有更多且更大的破骨細胞形成,以及更大面積的骨吸收。積雪草酸曾被證實在肝纖維化模型中誘導Smad7 基因的表達,也在本實驗中用以研究對骨質疏鬆疾病的作用。卵巢切除動物模型連續給藥8周後,骨質疏鬆的現象有明顯逆轉,表現為升高的骨形态学参数,及下降的股骨內破骨細胞融合標記蛋白的表達。 / 總結,本研究證實了Smad7在骨骼發育重建及骨疾病的病理機理等方面的研究提供了突破性的見解。部分敲除Smad7可以導致抑制性的成骨能力,促進性的破骨能力,以及損傷性的骨重建,亦會加速骨質疏鬆的進程,并可作為全新的藥物治療靶點,提示Smad7 本身對於骨重建及骨代謝的保護性作用,為代謝性骨疾病的研究及其臨床藥物開發提供了更廣泛的前景。 / Smad7 has been well documented as a negative regulator of TGF-β signaling, and its altered expression often leads to human diseases such as cancer and fibrosis. However, the role of Smad7 in regulating bone remodeling and related diseases remains unclear. We performed both in vivo and in vitro experiments as well as disease model and drug therapy studies using both wild-type (WT) and Smad7ΔE1 (KO) mice to investigate the functional role of Smad7 in bone remodeling, osteoporosis, and MSCs differentiation. / The Smad7ΔE1 mice were generated by replacing part of the exon1 of Smad7 gene as reported, which resulted in truncated protein and partial loss of Smad7 function. Mice were genotyped by PCR. The μ-CT, histological assays and bone histomorphometric assays in metaphysic region of the femurs showed lower trabecular number (TbN), trabecular thickness (TbTh), mineral apposition rate (MAR), higher trabecular separation (TbSp) and Osteoclast Surface (Oc.S/BS & Oc.N/BS) in the KO mice at 6, 12, to 24 weeks old; as well as lower bone mineral density (BMD) and bone volume fraction (BV/TV) at 24 weeks old in the KO mice. The in vitro BM-MSCs multi-lineage differentiation studies showed the suppressed osteogenic potential in the KO group with fewer mineralized nodules, lower ALP activity and expression of Col1A1, Runx2 and OCN; while the adipogenic potential was elevated with more lipid droplets formation and higher expression of Adipsin and C/EBPα. The osteoclastogenic potential of KO mice BMMs was also elevated, showing higher osteoclasts activity and larger resorptive areas, as well as elevated expression of TRAP and CTR. Both in vivo and in vitro studies of the osteoporotic models showed that the KO mice had lower BMD, TbTh, and higher TbSp compared to the WT mice at 4, 8, 16 weeks after OVX, similar results of lower BV/TV and TbN were observed at 4 weeks after OVX in the KO mice. The RANKL-induced osteoclastogenesis potential was elevated compared to WT mice, with more and bigger osteoclasts, larger resorptive areas, as well as elevated expression of TRAP and CTR. The osteoclastic cell fusion was also enhanced. Treatment of Asiatic acid (one traditional Chinese medicine that has been proved to induce the expression of Smad7 as reported) in the OVX mice reversed the osteoporotic process with increase BMD, BV/TV, TbN, TbTh, and decreased TbSp compared to the untreated group. The osteoclastic cell fusion was suppressed after AA treatment. / Partial loss of Smad7 function leads to impaired bone remodeling in vivo, reduced osteogenesis and enhanced osteoclastogenesis in vitro, and also accelerates the osteoporotic development and osteoclastic cell fusion. Asiatic acid may be a novel potential drug for prevention of osteoporosis. Our findings provide new evidences for a better understanding of the biological functions of Smad7 in bone remodeling and its therapeutic potential for metabolic bone diseases. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Nan. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 131-153). / Abstracts also in Chinese.
218

Revitalization of industrial buildings in San Po Kong

Lee, Wing-kin., 李永健. January 2004 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
219

Depots redefined : an analysis of rehabilitating historic railroad depots in Indiana

Shrack, Ryan W. 09 July 2011 (has links)
The railroad depot has played an integral role in countless towns and cities throughout the state of Indiana and in other regions of the nation. In many communities, the depot served as the local newsstand, post office, and social gathering place. A community’s railroad depot was a symbol of pride, which was evident by the significant level of architectural detail found in these transportation edifices. Over the course of the past fifty years, a vast majority of these architectural gems have fallen into disrepair, or worse, been demolished because it was believed that the depot could no longer fulfill a viable role in a post-railroad oriented society. There have been multiple efforts to rehabilitate the railroad depot by both the private and public sectors. Although many efforts have been made, there are still numerous historic depots throughout Indiana that are in need of assistance and in danger of being razed. Therefore, this thesis investigates the role of the depot in Indiana towns and cities today by looking at different rehabilitation projects that have successfully saved the railroad depot and transformed it once again into an active member of the local community. / History of the railroad industry in Indiana -- Development of the railroad depot in Indiana -- Literature review on railroad depot rehabilitation -- Methodology for case studies -- Depot rehabilitation case studies -- Conclusion. / Department of Architecture
220

Arterial Response to Local Mechanical Variables: The Effects of Circumferential and Shear Stress

Wayman, Brian H. 09 April 2007 (has links)
Arteries respond to changes in global mechanical parameters (pressure, flow rate, and longitudinal stretching) by remodeling to restore local parameters (circumferential stress, shear stress, and axial strain) to baseline levels. Because a change in a single global parameter results in changes of multiple local parameters, the effects of individual local parameters on remodeling remain unknown. This study uses a novel approach to study remodeling in organ culture based on independent control of local mechanical parameters. The approach is illustrated by studying the effects of circumferential and shear stress on remodeling-related biological markers. Porcine carotid arteries were cultured for three days at a circumferential stress of 50 kPa or 150 kPa or, in separate experiments, a shear stress of 0.75 Pa or 2.25 Pa. At high circumferential stress, matrix synthesis, smooth muscle cell proliferation, and cell death are significantly greater, but matrix metalloproteinase-2 (MMP-2) and pro-MMP-2 activity are significantly less. In contrast, biological markers measured were unaffected by shear stress. Applications of the proposed approach for improved understanding of remodeling, optimizing mechanical conditioning of tissue engineered arteries, and selection of experimentally motivated growth laws are discussed.

Page generated in 0.0895 seconds