Diss. (sammanfattning) Linköping : Linköping University, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Michigan, 1960.

published_or_final_version / Pharmacology / Doctoral / Doctor of Philosophy

Memoria para optar al Título Profesional de Médico Veterinario / La calcificación arterial es un importante factor de riesgo asociado a morbilidad y mortalidad cardiovascular. La arterioesclerosis o esclerosis de Mönckeberg es un tipo de calcificación que involucra específicamente a la túnica media arterial, aumentando la rigidez de vasos de distinto calibre. Una situación clínica en que se observa un desarrollo rápido y agresivo de complicaciones cardiovasculares es la insuficiencia renal crónica, donde existe una alteración del metabolismo fosfo-cálcico y la presencia de hiperaldosteronismo, lo que contribuiría a la calcificación arterial y daño cardiovascular. Estudios recientes indican que la arterioesclerosis ocurre mediante la captación activa de fosfato por el tejido vascular, mediada por un cotransportador de fosfato dependiente de sodio (NaPi), que utiliza el fosfato como sustrato para la formación de cristales de hidroxiapatita. NaPi-III es el mediador de la captación de fosfato en los tejidos cardiovasculares, en los que se expresan dos isoformas: Pit-1 y Pit-2. Al aumentar la captación de fosfato, las células de músculo liso de la pared arterial sufren un cambio fenotípico, activando un programa de diferenciación de tipo osteocondrogénica. En el presente trabajo se estudió el efecto de aldosterona sobre la actividad y expresión del cotransportador sodio-fosfato NaPi-III y la diferenciación osteocondrogénica en el tejido arterial. Ratas macho fueron sometidas a nefrectomía 5/6 y divididas en 3 grupos: SHAM (control), NPX (nefrectomía 5/6) y NPXspi (NPX más tratamiento con espironolactona, un antagonista del receptor de aldosterona, 15 mg/Kg/día). Se extrajeron aortas de ratas sanas, las que fueron incubadas durante 18 a 24 horas con aldosterona y/o espironolactona, obteniendo los siguientes grupos experimentales: CONTROL (vehículo), ALDO (aldosterona 10-9 a 10-7 M), SPI (espironolactona 5*10-6 M) y ALDO+SPI (aldosterona 10-7 M más espironolactona 5*10-6 M). La actividad de NaPi-III en anillos aórticos fue evaluada mediante captación de 32P sensible a arseniato de sodio (10 mM) o ácido fosfonofórmico (1 mM). Las ratas urémicas presentaron un significativo aumento en la actividad NaPi (SHAM: 196±8; NPX: 437±128 cpm/mg tejido húmedo/10 min; P < 0,05 vs SHAM). Espironolactona previno el aumento de la actividad NaPi (NPXspi: 173±38 cpm/mg tejido húmedo/10 min). Se realizaron western blot con un anticuerpo específico para Pit-1 en los grupos de ratas, observándose un aumento significativo en la expresión de esta proteína en el grupo NPX, comparado con SHAM y NPXspi (SHAM: 1,334+0,139; NPX: 2,205+0,337; NPXspi: 1,027+0,328 unidades arbitrarias (u.a.); P < 0,05 NPX vs SHAM y NPXspi). La actividad NaPi también aumentó significativamente en los explantes 8 del grupo ALDO (10-7 M) respecto al CONTROL (CONTROL: 242±30; ALDO: 868±67 cpm/mg tejido húmedo/10 min; P < 0,01). Mediante western blot se demostró que los explantes arteriales presentaron un aumento dosis dependiente de Pit-1 frente a concentraciones crecientes de aldosterona (CONTROL: 1; ALDO 10-9 M: 1,228±0,197; ALDO 10-8 M: 1,653±0,299; ALDO 10-7 M: 2,051±0,440 u.a.; obteniéndose una diferencia significativa en los dos últimos grupos con respecto al CONTROL, P < 0,05) como también se observó la inhibición del efecto positivo de aldosterona sobre Pit-1, a través de espironolactona, sin diferencias importantes entre los grupos CONTROL, SPIRO y ALDO+SPIRO y un aumento significativo de Pit-1 en el grupo ALDO (10-7 M) (CONTROL: 1; SPI: 1,032±0,072; ALDO: 1,599±0,281; ALDO+SPI: 1,045±0,120 u.a.; P < 0,05). Se evaluó mediante RT-PCR la abundancia relativa de mRNA del gen Cbfa-1, factor de transcripción típico de la diferenciación osteocondrogénica, observándose un aumento importante en la expresión de este gen en los explantes estimulados con aldosterona 10-7 M (ALDO), mientras que no existe una diferencia significativa entre los grupos CONTROL, SPI y ALDO+SPI (CONTROL: 0,92±0,15; SPI: 0,76±0,27; ALDO: 2,20±0,71; ALDO+SPI: 1,04±0,25 ng; P < 0,05). Estos resultados demuestran una regulación de la actividad y expresión de Pit-1 en el tejido arterial por aldosterona y su relación en la activación del programa de diferenciación osteocondrogénica que ocurre en la calcificación arterial.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / Vita. / Includes bibliographical references. / Ph.D.

Atherosclerosis is the chief cause of acute coronary syndromes and may progress for many years before any noticeable clinical syndromes occur. Hyperlipidemia is the common clinical problem for people adopting a western style of living and it can initiate a series of vascular events that result in atherosclerosis. The pathological processes include the accumulation of modified lipid, mainly oxidized low-density lipoprotein (oxLDL), endothelial cell dysfunction and activation, increase in expression of adhesion molecules, activation and recruitment of inflammatory cells and induction of proliferation and migration of vascular smooth muscle cells. / Endothelial-monocyte adhesion is crucial process for the recruitment of monocyte into intima. DG (7:3), Danshen and SAB were found to inhibit TNF-alpha-induced endothelial-monocyte adhesion. They also showed inhibition on TNF-alpha induced production of chemokines, MCP-1 which promotes the transmigration of monocyte. However, it did not inhibit the production of cytokine, IL-6 which stimulates the expression of adhesion molecules such as VCAM-1 and ICAM-1. / For the in vivo study, DG (7:3) exhibited no anti-hyperlipidemic or hypolipidemic effect against diet-induced hyperlipidemia, nor did it lower cholesterol level in hamsters. Also, it did not inhibit HMG-CoA reductase activity or increase the total fecal sterols excretion. However, DG (7:3) exhibited hypocholesterolemic effect on diet-induced hyperlipidemia in the rabbit model, wherein it could lower plasma total cholesterol and liver cholesterol level. Moreover, it could significantly decrease the atheroma formation. / In the present study, the anti-oxidative effects of herbal extract/compound were measured by three in vitro assays, namely the inhibition of 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH)-induced red blood cells hemolysis, AAPH-induced cardiomyocyte (H9c2) cells death and Cu2+-induced low-density lipoprotein oxidation. The results showed that the aqueous extract of the compound formula Danshen (D) and Gegen (G) (7:3), abbreviated as DG (7:3), and an aqueous extract of Danshen as well as salvianolic acid B (SAB) exhibited anti-oxidant effect, but Gegen did not produce such effect. It was found that SAB showed a stronger anti-oxidant effect than that of ascorbic acid. / Proliferation and migration of vascular smooth muscle cells (vSMCs) are important pathological processes involved in the development of atherosclerosis. DG (7:3), Danshen and SAB were found to inhibit PDGF-induced vSMCs proliferation through G1/S cell cycle arrest. Cyclin D, a main component that governs the transition of G1 phase to S phase, was found to be down-regulated by DG (7:3), Danshen and SAB, as assessed by measurements of both protein and mRNA levels. Moreover, DG (7:3), Danshen and SAB showed anti-migratory effect against platelet-derived growth factor-induced vSMCs migration. / To summarize, DG (7:3) was found to have potential to produce anti-atherosclerotic effect by inhibiting the LDL oxidation, proliferation and migration of vascular SMC, thereby preventing the formation of atheroma plaque. / Koon Chi Man. / "March 2006." / Adviser: Kwok Pui Fung. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6324. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 246-264). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Qiao, Mu. / "June 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 190-209). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

by Chan Chi Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 119-137). / Chapter SECTION 1 --- INTRODUCTION / Chapter 1.1 --- Overview on lipids --- p.2 / Chapter 1.1.1 --- Definition and Classification of Lipids --- p.2 / Chapter 1.1.2 --- Lipoproteins and Apolipoproteins --- p.4 / Chapter 1.1.3 --- Outline of Lipoprotein Metabolism --- p.9 / Chapter 1.1.4 --- LDL Metabolism --- p.12 / Chapter 1.2 --- Dyslipidaemia and Cardiovascular Disease (CVD) --- p.16 / Chapter 1.2.1 --- Definition --- p.16 / Chapter 1.2.2 --- Dyslipidaemia and CAD --- p.16 / Chapter 1.2.3 --- Dyslipidaemia in Non-Insulin Dependent Diabetes Millitus Patients --- p.18 / Chapter 1.2.4 --- Claasification of Dyslipidaemia --- p.24 / Chapter 1.2.5 --- Causes of Hyperlipidaemia --- p.26 / Chapter 1.3 --- Dyslipidaemia and Atherosclerosis --- p.29 / Chapter 1.3.1 --- Pathogenesis of Atherosclerosis --- p.29 / Chapter 1.3.2 --- Mechanism of Atherogenesis --- p.31 / Chapter 1.3.3 --- Intrinsic Roles of LDL in Atherogenesis --- p.33 / Chapter (1) --- LDL Oxidizability --- p.33 / Chapter (2) --- LDL Particle Size Heterogeneity --- p.39 / Chapter 1.4 --- Management of Dyslipidaemia --- p.42 / Chapter 1.5 --- Aims of This Study --- p.49 / Chapter SECTION 2 --- MATERIALS AND METHODS / Chapter 2.1 --- Materials --- p.52 / Chapter 2.1.1 --- Patients and Controls --- p.52 / Chapter 2.1.2 --- Drug Administration Trials --- p.54 / Chapter 2.1.3 --- Blood Samples --- p.55 / Chapter 2.1.4 --- Biochemicals --- p.56 / Chapter 2.1.5 --- Solutions and Buffers --- p.56 / Chapter 2.1.6 --- Apparatus and Equipment --- p.60 / Chapter 2.2 --- Methods --- p.62 / Chapter 2.2.1 --- General Clinical Biochemistry Tests --- p.62 / Chapter 2.2.2 --- Apolipoprotein Assays --- p.62 / Chapter 2.2.3 --- Ultracentrifugation of LDL Fraction --- p.63 / Chapter 2.2.4 --- De-Salting of LDL Fraction --- p.64 / Chapter 2.2.5 --- Qualitative Determination of LDL-Cholesterol and Protein Fractions --- p.64 / Chapter 2.2.6 --- In Vitro Assessment of LDL Oxidizability --- p.65 / Chapter 2.2.7 --- Electrophoretic Gel Pattern of LDL Fraction During In Vitro Oxidizability --- p.65 / Chapter 2.2.8 --- Study of LDL Particle Size --- p.66 / Chapter 2.2.9 --- Statistical Analysis --- p.67 / Chapter SECTION 3 --- RESULTS / Chapter 3.1 --- Quantitative Determination and Standardization of LDL Fractions --- p.69 / Chapter 3.2 --- In Vitro Assessment of LDL Oxidizability --- p.72 / Chapter 3.3 --- Electrophoretic Patterns of LDL during In Vitro Oxidizability --- p.72 / Chapter 3.4 --- LDL Sizing --- p.73 / Chapter 3.5 --- "Correlations of Triglycerides Concentration, LDL Particle Size and Oxidizability" --- p.76 / Chapter 3.6 --- Diabetes Millitus --- p.83 / Chapter 3.6.1 --- NIDDM Patients & Controls --- p.83 / Chapter 3.6.2 --- Effect of Drug Treatment on Serum Lipid-Lipoprotein- Apolipoprotein Profile --- p.86 / Chapter 3.7 --- Hypertriglyceridaemic Patients --- p.90 / Chapter 3.7.1 --- Patients & Controls --- p.90 / Chapter 3.7.2 --- Bezafibrate Treatment --- p.91 / Chapter 3.8 --- CAD Patients --- p.97 / Chapter 3.8.1 --- CAD Patients & Controls --- p.97 / Chapter SECTION 4 --- DISCUSSION / Chapter 4.1 --- Patients and Controls --- p.101 / Chapter 4.2 --- Ultracentrifugation of LDL Fractions --- p.102 / Chapter 4.3 --- In Vitro LDL Oxidizability --- p.103 / Chapter 4.4 --- "Association of TG, LDL Oxidizability and Particle Size" --- p.105 / Chapter 4.5 --- LDL Sizing --- p.106 / Chapter 4.6 --- Comparsion of Patients and Controls in Lipid-Lipoprotein- Apolipoprotein Profiles --- p.107 / Chapter 4.7 --- The Effect of Lovastatin and Acipimox on NIDDM Patients --- p.111 / Chapter 4.8 --- The Effect of Bezafibrate on Hypertriglyceridaemic Patients --- p.114 / Chapter SECTION 5 --- CONCLUSION --- p.116 / References --- p.119 / Appendices --- p.138

The overall goals of this project were to develop microstructurally based constitutive models to characterize the mechanical behavior of arteries and to investigate the effects of HIV proteins and antiretroviral drugs on the microstructure and mechanical behavior. To this end we created several constitutive models in aim 1 using a rule of mixtures approach, investigated the role of viral proteins in aim 2 through the use a transgenic mouse model, and studied the effects of the antiretroviral drug AZT administered to mice in aim 3. It is well known that the local mechanical environment which cells experience mediates growth and remodeling and that subsequent growth and remodeling can change that mechanical environment. This remodeling includes changes in the content and organization of the constituents of arteries (collagen, elastin, and smooth muscle cells). The first aim thus created models that incorporated the content and organization of these constituents using a rule-of-mixtures approach. The models we developed were able to capture the mechanical behavior of the arteries as well as previously developed phenomenological models while providing more physical meaning to the parameters, some which can be measured experimentally for incorporation into future models. Aims 2 and 3 investigated the mechanical and microstructural changes to murine arteries in response to HIV proteins or the drug AZT. While the development of antiretroviral therapy has greatly increased the life expectancy of patients with HIV, a number of other complications and co-morbidities including cardiovascular disease have become apparent. While clinical data has implicated both the virus and the antiretroviral drugs as playing roles, this work addressed the need of investigating these effects in a controlled manner. Specifically we used mouse models and focused on the two subclinical markers of increased intima-media thickness and arterial stiffening. Aim 2 used a transgenic mouse that expressed most of the human HIV proteins. We observed both intima-media thickening and arterial stiffening in alignment with clinical data. Other changes that also support a proatherogenic phenotype included decreased elastin content and changes in cathepsin activity. Aim 3 administered the antiretroviral drug AZT to healthy mice and we also observed the same subclinical markers of atherosclerosis including intima-media thickening and arterial stiffening as well as the other proatherogenic changes of decreased elastin and changes in cathepsin activity. Several other parameters including axial behavior, opening angles, collagen content, and collagen fiber angles were also quantified. These were important to fully characterize the vessel and may also be incorporated in the future into the constitutive models developed in aim1. In conclusion, in aim 1 we developed a microstructurally based constitutive model of arteries that effectively captures the mechanical behavior and includes parameters that have more physical meaning and some of which are experimentally tractable. Aims 2 and 3 both observed several subclinical markers of atherosclerosis in mice that express HIV proteins or were given AZT, providing a good model for future work and suggesting that both the HIV virus and antiretroviral drugs may play roles in the development of atherosclerosis in HIV.