INTRODUÇÃO: A Síndrome metabólica (SM) é uma condição clínica complexa, onde há associação de obesidade abdominal e distúrbios do metabolismo da glicose e lipídeos. Essencialmente, sua fisiopatologia envolve o aumento da resistência insulínica periférica, a qual acelera o processo de aterosclerose. Sendo assim, a SM apresenta-se como um cofator para aumento da incidência de doenças cardiovasculares, incluindo a doença cerebrovascular. Frequentemente, a aterosclerose carotídea é avaliada pela ultrassonografia Doppler (USG-D), a qual determina apenas o grau de estenose. No entanto, em determinadas situações, a avaliação qualitativa da placa carotídea é importante para conduta terapêutica. OBJETIVO: O objetivo deste estudo foi avaliar o impacto da síndrome metabólica na morfologia de placa carotídea, acessada pela mediana de escala de cinza (GSM), e análise da distribuição de pixels utilizando um software dedicado a este propósito. MÉTODO: No período de setembro de 2011 a setembro de 2012, 83 pacientes assintomáticos portadores de estenose de artérias carótidas foram consecutivamente incluídos em um estudo transversal observacional. A coleta de dados envolveu avaliação clínico-laboratorial e USG-D realizada por um único examinador. A análise ultrassonográfica incluiu a obtenção de uma única imagem no melhor segmento longitudinal que demonstrasse a maior porção da placa. As imagens foram gravadas, sendo posteriormente avaliadas em um programa de computador dedicado a medida de GSM e análise da distribuição de pixels. RESULTADOS: No grupo total (n = 83), foi identificada média de idade de 72,23 ± 7,9 anos (52 - 90), com predominância do sexo masculino (53 %). A SM foi diagnosticada em 51,8% da casuística. Pacientes com a SM apresentaram maior prevalência de diabetes mellitus (53,5% vs. 27,5%, p = 0,016), utilizavam um maior número de classes de anti-hipertensivos (2 [0 - 4] vs. 2 [0 - 6], p = 0,009) e usavam estatinas há mais tempo (60 vs. 48 meses, p = 0,011) quando comparados aos pacientes sem essa condição. Em ambos os grupos, houve predomínio de estenose carotídea de 50 - 69% (37,3 %) e a análise por distribuição de pixels foi realizada em 148 placas carotídeas. Nestas, a mediana do GSM foi superior em pacientes com a SM em relação aos pacientes sem esta condição (71 vs. 60,5, p = 0,012). Adicionalmente, o histograma demonstrou que pacientes com a SM apresentaram placas carotídeas mais estáveis, com maiores quantidades de tecido fibrótico (15,8 vs. 12, p = 0,015) e menores proporções de sangue (0,5 vs. 1,9, p = 0,005) e gordura (7,6 vs. 12,4, p = 0,003). CONCLUSÃO: O presente estudo demonstrou que a SM não foi associada a presença de instabilidade da placa carotídea / INTRODUCTION: Metabolic syndrome (MetS) is a complex clinical disorder in which abdominal obesity and impairment of glucose and lipid metabolism coexist. In essence, this condition involves increased peripheral insulin resistance, which is associated with atherosclerosis. Accordingly, MetS is a cofactor in atherosclerotic disease, including cerebrovascular disorders. Carotid artery stenosis is generally assessed by Doppler ultrasonography (DUS); however, some patients also require qualitative carotid plaque analysis to aid clinical decision-making. OBJECTIVE: To evaluate the impact of MetS on the morphology of carotid artery plaques as evaluated using DUS with computer-assisted analysis. METHOD: Between September 2011 and September 2012, 83 consecutive asymptomatic patients with carotid artery stenosis were enrolled in this cross-sectional observational study. We collected data from clinical and laboratory evaluations, and DUS conducted by a single operator. All plaques were scanned longitudinally and the best segment was selected, recorded, and evaluated using dedicated software. The main softwarebased analyses were grey-scale median (GSM) measurements and pixels distribution analysis. RESULTS: Of the total group (n = 83), 53% of subjects were male and the mean age was 72.23 ± 7.9 years (52-90). MetS was identified in 51.8% of patients. Compared with patients without MetS, patients with MetS had a higher incidence of diabetes mellitus (53.5% vs. 27.5%, p = 0.016), used more classes of antihypertensive drugs (2 [0 - 4] vs. 2 [0 - 6], p = 0.009), and were treated with statins for longer (60 vs. 48 months, p = 0.011). Both groups exhibited moderate carotid stenosis of 50% - 69% (37.3%) and MetS was not associated with an increased prevalence of severe carotid artery stenosis. In computer-assisted analysis of 148 carotid plaques, the median GSM was higher in the MetS group than in the non-MetS group (71 vs. 60.5, p = 0.012). Additionally, patients with MetS had more stable carotid artery plaques with higher amounts of fibrotic tissue (15.8 vs. 12, p = 0.015) and lower quantities of blood (1.9 vs. 0.5, p = 0.005) and fat (7.6 vs. 12.4, p = 0.003). CONCLUSION: In patients with asymptomatic carotid artery stenosis, MetS was not associated with unstable carotid plaques

Ensaios clínicos observacionais e em animais sugerem que o estrógeno exerça proteção cardiovascular, entretanto existem controvérsias mesmo após estudos randomizados. Tem sido sugerido que existe uma janela de oportunidade terapêutica, teoria timing hypothesis, que analisa o tratamento com estrógeno, iniciado precoce ou tardiamente, em mulheres na pós-menopausa. Avaliamos a função de carótidas de camundongos fêmeas com senescência acelerada (SAMP8) ou resistentes (SAMR1) ovariectomizadas tratadas com estrógeno precoce e tardiamente. Em SAMR1 os tratamentos promoveram vasculoproteção e nas carótidas das SAMP8 o tratamento com início precoce não alterou o efeito da ovariectomia, porém o tratamento com início tardio aumentou a vasoconstrição à fenilefrina, a produção de tromboxano (TXA2) e a expressão proteica do ERα-36kDa, splicing alternativo do receptor clássico ERα-66kDa. Portanto, os efeitos do estrógeno não foram benéficos no envelhecimento, podendo contribuir para o desenvolvimento de doenças cerebrovasculares decorrentes de alteração na circulação cerebral. / Observational clinical trials and animal studies demonstrated that estrogen promote cardiovascular protection. However, there are controversies after randomized clinical trials. It has been suggested that there is a therapeutic window of opportunity timing hypothesis theory , which analyzes the early and late estrogen treatments in postmenopausal women. We evaluated the carotid function in ovariectomized senescence (SAMP8) and resistant (SAMR1) female mice treated with estrogen in mineral oil solution dose of 5 g/kg by subcutaneous injection every three days. In SAMR1 estrogen treatments promoted vasculoprotection. In SAMP8 early-onset estrogen treatment did not change the effect observed in the ovariectomy, however late-onset estrogen treatment increased the vasoconstriction to phenylephrine, the thromboxane production and the protein expression of ERα-36kDa, alternative splicing. Therefore, the effects of estrogen were not beneficial in aging, contributing to the development of cardio and cerebrovascular diseases due to alteration cerebral circulation.

A Hipercolesterolemia Familiar (HF) é uma doença caracterizada por aterosclerose precoce. Contudo, o curso clínico da doença coronária na HF é variável. A detecção da aterosclerose subclínica, pela espessura íntima média (IMT) carotídea, calcificação da artéria coronariana (CAC) e da rigidez arterial pela velocidade de onda de pulso (VOP) em portadores de HF pode ser útil na estratificação do risco cardiovascular. O objetivo primário deste estudo foi avaliar se existe correlação da CAC, IMT e VOP em portadores de HF. Como objetivos secundários, comparar estes marcadores de aterosclerose subclínica nos HF em relação a controles pareados por idade e sexo (CTRL) e avaliar quais são os principais fatores que influenciam a VOP carotídeo-femoral a IMT carotídea e a CAC, em pacientes com HF. Material e Métodos: Analisamos 89 HF (39±14 anos, 38% homens, LDL-c médio de 279 mg/dL) e 31 controles pareados para sexo e idade (CTRL) (LDL-c médio de 102mg/dL). Determinamos o IMT pela ultra-sonografia de alta definição tipo \"echotracking\" (Wall-Track System2), a VOP pelo método Complior®, CAC pela tomografia de múltiplos detectores, perfil lipídico e variáveis bioquímicas como Lp(a), PCR as, apoA1 e apoB. Foram calculados respectivamente o risco de DAC em 10 anos e a carga de exposição ao colesterol pelos escore de Framingham (ERF) e pelo índice LDL-c x idade (LYS). Resultados: Os HF apresentaram maior ERF (%) (7 ± 3 vs. 3 ± 3, p=0,002), maior prevalência de CAC (34% vs. 12%, p=0,024), maior IMT (micra m) (653 ± 160 vs 593 ±111, p=0,027), maior VOP (m/s) (9,2 ±1,5 vs. 8,5 ± 0,9, p=0.007) e glóbulos brancos mais elevados (x109 células/L) (7,2 ± 2,0 vs 6,4 ± 1,5, p=0,046) do que CTRL. Não foram observadas diferenças de PCR as respectivamente 1,7 (0,2-3,4 mg/L) e 1,3 (0,2-8,0 mg/L), p=n.s. para HF e CTRL. Na análise multivariada os determinantes da IMT foram: pressão arterial sistólica. (r2=0,36, p=0,045), ERF (r2=0,26, p=0,0001) e Apo B (r2=0,32, p=0,02). A idade foi o único determinante da VOP (r2=0,37, p=0,0001). Os determinantes independentes da CAC como variável contínua foram: sexo masculino (r2=0,36, p=0,0027) e LYS (r2=0,29, p=0,0001). Os determinantes da presença ou ausência de CAC foram: estimativa de risco de DAC em 10 anos do ERF (P=0,0027) e o produto LDL-c X Idade (p=0,0228). Conclusão: Não foram encontradas correlações entre CAC, como variável continua ou categórica, IMT, VOP, na população com HF. Pacientes com HF têm maior prevalência de aterosclerose subclínica que os CTRL. / Familial hypercholesterolemia (FH) is associated with early onset of coronary heart disease (CHD). Detection of subclinical atherosclerosis (SCA) could be useful for risk stratification in FH subjects. The relationship among carotid, aortic and coronary SCA was not yet explored in FH. We studied the correlation among common carotid intima-media thickness (IMT), coronary artery calcification (CAC) and arterial stiffness (carotid-femoral pulse wave velocity-PWV) and their determinants in FH subjects. Methods: 89 FH subjects (39±14 Years, 38% male, median LDL-c = 279 mg/dL) and in 31 normal matched controls (NL) (median LDL-c 102mg/dL) were studied. IMT was determined by the Wall-Track System2, aortic stiffness (PWV) with the Complier® method, CAC prevalence and severity were measured by multidetector computed tomography. Clinical and laboratory variables (lipids, apolipoprotein AI and B, Lp(a), glucose, hsCRP and WBC) were determined. The 10-year CHD risk was calculated by Framingham scores (FRS) and the age-cholesterol burden by the LDL-cholesterol year score (LYS=LDL-c x age). Results: FH subjects had a greater FRS (%) (7 ± 3 vs. 3 ± 3, p=0.002), higher prevalence of CAC (34% vs. 12%, p=0.024), greater IMT values (micra m) (653 ± 160 vs 593 ±111, p=0.027), higher PWV (m/s) (9.2 ±1.5 vs. 8.5 ± 0.9, p=0.007) and white blood cels (x109 cels/L) (7.2 ± 2.0 vs 6.4 ± 1.5, p=0.046) than NL. No difference were found in median hsCRP levels (mg/L) respectively 1.7 (0.2-3.4) and 1.3 (0.2-8.0) p=n.s. for FH and NL. By multivariate analyses the following variables were independent determinants of: 1)IMT: systolic blood pressure (r2=0.36, p=0.045), FRS (r2=0.26, p=0.0001) and apolipoprotein B (r2=0.32, p=0.02). 2)PWV: age (r2=0.37, p=0.0001). 3)CAC as a continuous variable: male gender (r2=0.36, p=0.0027) and LYS (r2=0.29, p=0.0001). 4)Presence of CAC as a dichotomous variable: FRS (P=0.0027) and LYS (p=0.0228). Conclusions: No correlations was found among CAC either as a continuous or a dichotomous category, IMT, PWV, in FH subjects and clinical parameters poorly explained their variability, however subclinical atherosclerosis is more prevalent in FH than NL.

The mechanical behavior of the arterial wall is determined by the composition and structure of its internal constituents as well as the applied traction-forces, such as pressure and axial stretch. The purpose of this work is to develop new theoretical frameworks and experimental methodologies to further the understanding of arterial mechanics and role of the various intrinsic and extrinsic mechanically motivating factors. Specifically, residual deformation, matrix organization, and perivascular support are investigated in the context of their effects on the overall and local mechanical behavior of the artery. We propose new kinematic frameworks to determine the displacement field due to residual deformations previously unknown, which include longitudinal and shearing residual deformations. This allows for improved predictions of the local, intramural stresses of the artery. We found distinct microstructural differences between the femoral and carotid arteries from non-human primates. These arteries are functionally and mechanically different, but are geometrically and compositionally similar, thereby suggesting differences in their microstructural alignments, particularly of their collagen fibers. Finally, we quantified the mechanical constraint of perivascular support on the coronary artery by mechanically testing the artery in-situ before and after surgical exposure.

Background and Purpose: The endothelium is a single-cell layer positioned at the blood-vascular wall interface, where in response to blood-borne signals and hemodynamic forces, endothelial cells act as central regulators of vascular homeostatic processes including vascular tone, growth and remodeling, inflammation and adhesion, and blood fluidity and coagulation. Agonist- or flow-stimulated endothelium-dependent vasorelaxation becomes impaired in states of cardiovascular disease (CVD) risk and has been identified as a possible biomarker of overall endothelial dysfunction leading to vascular dysregulation and disease pathogenesis. Accordingly, it is important to elucidate the mechanisms accounting for this endothelial vasomotor dysfunction. Upon stimulation, endothelial cells can synthesize and release a variety of endothelium-derived relaxing factors (EDRFs), the most prominent of which is nitric oxide (NO) derived from NO synthase (NOS). In addition, under certain CVD risk conditions including hypertension and aging, stimulated endothelial cells can become a prominent source of endothelium-derived contracting factors (EDCFs) produced in a cyclooxygenase (COX)-dependent manner. Consequently, endothelial dysfunction may be caused by under-active EDRF signaling and/or competitive over-active EDCF signaling. Much attention has been given to elucidating the mechanisms of under-active EDRF signaling and its role in causing endothelial dysfunction, wherein excess reactive oxygen species (ROS) accumulation and oxidative stress under CVD risk conditions have been recognized as major factors in reducing NO bioavailability thus causing under-active EDRF signaling and endothelial dysfunction. Less attention however, has been given to elucidating the mechanisms of over-active COX-mediated EDCF signaling and its role in causing endothelial dysfunction. Moreover, while COX-mediated EDCF signaling activity has been investigated in some segments of the vasculature, most notably the aorta, it has not been well-investigated in the common carotid artery (CCA), a highly accessible cerebral blood flow conduit particularly advantageous in exploring the roles of the endothelium in vascular pathogenesis. It was the global purpose of this thesis to gain a better understanding of the cellular-molecular mechanisms accounting for endothelial dysfunction in the CCA of animal models known to exhibit COX-mediated EDCF signaling activity, in particular essential (spontaneous) hypertension and aging. Experimental Objective and Approach: This thesis comprises three studies. Study I and Study II investigated the CCA of young-adult (16-24wk old) normotensive Wistar Kyoto (WKY) and Spontaneously Hypertensive (SHR) rats. Study III investigated the CCA of Adult (25-36wks old) and Aging (60-75wks old) Sprague Dawley (SD) rats treated in vivo (or not; CON) with L-buthionine sulfoximine (BSO) to chronically deplete the cellular anti-oxidant glutathione (GSH) and increase ROS accumulation and oxidative stress. The global objective and approach across these studies was to systematically examine the relative contributions of NOS and COX signaling pathways in mediating the acetylcholine (ACh)-stimulated endothelium-dependent relaxation (EDRF) and contractile (EDCF) activities of isometrically-mounted CCA in tissue baths in vitro, with a particular focus on elucidating the mechanisms of COX-mediated EDCF signaling activity. An added objective was to examine the in vivo hemodynamic characteristics of the CCA in each animal model investigated, serving both to identify the pressure-flow environment that the CCA is exposed to in vivo and to provide assessment of potential hypertension, aging, and oxidative stress effects on large artery hemodynamics. Key Findings: Study I hemodynamic analysis confirmed a hypertensive state in young adult SHR while also exposing a reduction in mean CCA blood flow in SHR compared to WKY accompanied by a multi-faceted pressure-flow interaction across the cardiac cycle relating to flow and pressure augmentation. Study III hemodynamic analysis found that neither aging nor chronic BSO-induced GSH depletion affected CCA blood pressure or blood flow parameters in SD rats. Study I and II demonstrated that a COX-mediated EDCF response impaired ACh-stimulated endothelium-dependent vasorelaxation in pre-contracted CCA from young adult SHR, while EDRF signaling activity, predominantly mediated by NO, remained well-preserved compared to WKY. Examining ACh-stimulated contractile function specifically from a quiescent (non pre-contracted) state revealed that EDCF activity did exist in WKY CCA but could be completely suppressed by NO-mediated EDRF signaling activity, whereas the similarly robust NO-meditated EDRF signaling activity in SHR CCA could not fully suppress its >2-fold augmented EDCF activity vs. WKY CCA. Further pharmaco-dissection of ACh-stimulated contractile function in the SHR-WKY CCA model revealed that the EDCF signaling activity was completely dependent on the COX-1 (but not COX-2) isoform of COX and was almost exclusively mediated by the thromboxane-prostanoid (TP) sub-type of the prostaglandin (PG) G-protein coupled receptor family and by Rho-associated kinase (ROCK), a down-stream effector of the molecular switch RhoA. Furthermore, it was found that while exogenous ROS-stimulated CCA contractile function was similarly >2-fold augmented in SHR vs. WKY and dependent on COX-1 and TP receptor and ROCK effectors, ACh-stimulated CCA EDCF signaling activity was only minimally affected by in-bath ROS manipulating compounds. Additional biochemical and molecular analysis revealed that ACh stimulation was associated with PG over-production from an over-expressed COX-1 in SHR CCA, and with CCA plasma membrane localization and activation of RhoA. Study III demonstrated that a COX-mediated EDCF response impaired ACh-stimulated endothelium-dependent vasorelaxation in pre-contracted CCA from Aging SD rats, while EDRF signaling activity, predominantly mediated by NO, remained well-preserved compared to Adult SD rats. Specific examination of ACh-stimulated contractile function revealed that EDCF activity did exist in Adult CCA but could be completely suppressed by NO-mediated EDRF signaling activity, whereas the similarly robust NO-meditated EDRF signaling activity in Aging CCA could not fully suppress its >3-fold augmented EDCF activity vs. Adult CCA. Further pharmaco-dissection of ACh-stimulated contractile function in the Adult-Aging SD rat CCA model revealed that EDCF signaling activity was completely dependent on COX-1, but while exogenous ROS was able to elicit a COX-dependent CCA contractile response, in-bath ROS manipulating compounds were found to be without effect on ACh-stimulated CCA EDCF signaling activity. Furthermore, biochemical analysis revealed that aging was not associated with a change in tissue (liver and vascular) GSH content or ROS accumulation. Chronic in vivo BSO treatment was effective in depleting tissue GSH content and increasing ROS accumulation, to a similar extent, in both Adult and Aging SD rats. However, regardless of age, neither ACh-stimulated NO-mediated EDRF signaling activity nor COX-mediated EDCF signaling activity were affected by these BSO-induced perturbations. Conclusions and Perspective: In the CCA of animals at the early pathological stages of either essential hypertension (young adult SHR) or normotensive aging (Aging SD rats), endothelial vasomotor dysfunction can be caused solely by over-active EDCF signaling, apparently disconnected from changes in NO bioavailability or oxidative stress. While NO and ROS may act, respectively, as negative and positive modulators of the established COX-PG-TP receptor-RhoA-ROCK cell-signaling axis mediating endothelium-dependent contractile activity, these factors do not appear to be essential to the mechanism(s) underlying the development of over-active EDCF signaling. Further elucidation of the cellular-molecular causes of over-active EDCF signaling, and its patho-biological consequences, in the SHR-WKY and Adult-Aging SD rat CCA models of EDCF activity established and hemodynamically characterized in this thesis, may help to identify new or more effective targets to be used in prevention or treatment strategies to combat the pathogenesis of CVD.

Ischemic brain injury causes neurodegeneration. In this study, the mechanism of neurodegeneration was investigated by examining the role of sterol regulatory element binding protein-1 (SREBP-1), CCAAT enhancer binding protein&amp / #946 / (C/EBP&amp / #946 / ), glutathione (GSH), malondialdehyde (MDA), glutathione-S-transferase (GST), and superoxide dismutase (SOD). Carotid artery occlusion (CAO) plus hypotension was produced for 10 minutes. Control groups were sham operated. Animals were sacrificed after 24 hours, 1 week, 2 and 4 weeks of reperfusion periods. The expression of C/EBP&amp / #946 / and SREBP-1 in rat brain cortex and cerebellum were examined by western blotting. C/EBP&amp / #946 / expressions significantly increased in both cytosolic (1.19, 1.58 fold) and nuclear (1.73, 1.81 fold) extracts of brain cortex at 24 hours and 1 week CAO groups, respectively. In cerebellum, C/EBP&amp / #946 / expression significantly increased in 1 week, cytosolic (1.63 fold), and nuclear (1.35 fold) extracts. SREBP-1 expression increased significantly in both cytosolic (2.07 fold) and nuclear (1.41 fold) extracts of brain cortex in 1 week. SREBP-1 expression significantly increased in cytosolic (2.15 fold) and nuclear (1.79 fold) extracts of cerebellum in 1 week. There were no significant alterations in SREBP-1 C/EBP&amp / #946 / expressions for 2 and 4 weeks in both cytosolic and nuclear extracts of brain cortex and cerebellum. There were insignificant changes in GSH and GST levels in cortex. However, MDA and SOD levels significantly increased by 43.0 % and 47.3 %, respectively, in 24 hours. Our findings indicate that increase in SREBP-1 and C/EBP&amp / #946 / expressions may be related to oxidative stress during ischemic neurodegenerative processes.

Background and Purpose: The endothelium is a single-cell layer positioned at the blood-vascular wall interface, where in response to blood-borne signals and hemodynamic forces, endothelial cells act as central regulators of vascular homeostatic processes including vascular tone, growth and remodeling, inflammation and adhesion, and blood fluidity and coagulation. Agonist- or flow-stimulated endothelium-dependent vasorelaxation becomes impaired in states of cardiovascular disease (CVD) risk and has been identified as a possible biomarker of overall endothelial dysfunction leading to vascular dysregulation and disease pathogenesis. Accordingly, it is important to elucidate the mechanisms accounting for this endothelial vasomotor dysfunction. Upon stimulation, endothelial cells can synthesize and release a variety of endothelium-derived relaxing factors (EDRFs), the most prominent of which is nitric oxide (NO) derived from NO synthase (NOS). In addition, under certain CVD risk conditions including hypertension and aging, stimulated endothelial cells can become a prominent source of endothelium-derived contracting factors (EDCFs) produced in a cyclooxygenase (COX)-dependent manner. Consequently, endothelial dysfunction may be caused by under-active EDRF signaling and/or competitive over-active EDCF signaling. Much attention has been given to elucidating the mechanisms of under-active EDRF signaling and its role in causing endothelial dysfunction, wherein excess reactive oxygen species (ROS) accumulation and oxidative stress under CVD risk conditions have been recognized as major factors in reducing NO bioavailability thus causing under-active EDRF signaling and endothelial dysfunction. Less attention however, has been given to elucidating the mechanisms of over-active COX-mediated EDCF signaling and its role in causing endothelial dysfunction. Moreover, while COX-mediated EDCF signaling activity has been investigated in some segments of the vasculature, most notably the aorta, it has not been well-investigated in the common carotid artery (CCA), a highly accessible cerebral blood flow conduit particularly advantageous in exploring the roles of the endothelium in vascular pathogenesis. It was the global purpose of this thesis to gain a better understanding of the cellular-molecular mechanisms accounting for endothelial dysfunction in the CCA of animal models known to exhibit COX-mediated EDCF signaling activity, in particular essential (spontaneous) hypertension and aging. Experimental Objective and Approach: This thesis comprises three studies. Study I and Study II investigated the CCA of young-adult (16-24wk old) normotensive Wistar Kyoto (WKY) and Spontaneously Hypertensive (SHR) rats. Study III investigated the CCA of Adult (25-36wks old) and Aging (60-75wks old) Sprague Dawley (SD) rats treated in vivo (or not; CON) with L-buthionine sulfoximine (BSO) to chronically deplete the cellular anti-oxidant glutathione (GSH) and increase ROS accumulation and oxidative stress. The global objective and approach across these studies was to systematically examine the relative contributions of NOS and COX signaling pathways in mediating the acetylcholine (ACh)-stimulated endothelium-dependent relaxation (EDRF) and contractile (EDCF) activities of isometrically-mounted CCA in tissue baths in vitro, with a particular focus on elucidating the mechanisms of COX-mediated EDCF signaling activity. An added objective was to examine the in vivo hemodynamic characteristics of the CCA in each animal model investigated, serving both to identify the pressure-flow environment that the CCA is exposed to in vivo and to provide assessment of potential hypertension, aging, and oxidative stress effects on large artery hemodynamics. Key Findings: Study I hemodynamic analysis confirmed a hypertensive state in young adult SHR while also exposing a reduction in mean CCA blood flow in SHR compared to WKY accompanied by a multi-faceted pressure-flow interaction across the cardiac cycle relating to flow and pressure augmentation. Study III hemodynamic analysis found that neither aging nor chronic BSO-induced GSH depletion affected CCA blood pressure or blood flow parameters in SD rats. Study I and II demonstrated that a COX-mediated EDCF response impaired ACh-stimulated endothelium-dependent vasorelaxation in pre-contracted CCA from young adult SHR, while EDRF signaling activity, predominantly mediated by NO, remained well-preserved compared to WKY. Examining ACh-stimulated contractile function specifically from a quiescent (non pre-contracted) state revealed that EDCF activity did exist in WKY CCA but could be completely suppressed by NO-mediated EDRF signaling activity, whereas the similarly robust NO-meditated EDRF signaling activity in SHR CCA could not fully suppress its >2-fold augmented EDCF activity vs. WKY CCA. Further pharmaco-dissection of ACh-stimulated contractile function in the SHR-WKY CCA model revealed that the EDCF signaling activity was completely dependent on the COX-1 (but not COX-2) isoform of COX and was almost exclusively mediated by the thromboxane-prostanoid (TP) sub-type of the prostaglandin (PG) G-protein coupled receptor family and by Rho-associated kinase (ROCK), a down-stream effector of the molecular switch RhoA. Furthermore, it was found that while exogenous ROS-stimulated CCA contractile function was similarly >2-fold augmented in SHR vs. WKY and dependent on COX-1 and TP receptor and ROCK effectors, ACh-stimulated CCA EDCF signaling activity was only minimally affected by in-bath ROS manipulating compounds. Additional biochemical and molecular analysis revealed that ACh stimulation was associated with PG over-production from an over-expressed COX-1 in SHR CCA, and with CCA plasma membrane localization and activation of RhoA. Study III demonstrated that a COX-mediated EDCF response impaired ACh-stimulated endothelium-dependent vasorelaxation in pre-contracted CCA from Aging SD rats, while EDRF signaling activity, predominantly mediated by NO, remained well-preserved compared to Adult SD rats. Specific examination of ACh-stimulated contractile function revealed that EDCF activity did exist in Adult CCA but could be completely suppressed by NO-mediated EDRF signaling activity, whereas the similarly robust NO-meditated EDRF signaling activity in Aging CCA could not fully suppress its >3-fold augmented EDCF activity vs. Adult CCA. Further pharmaco-dissection of ACh-stimulated contractile function in the Adult-Aging SD rat CCA model revealed that EDCF signaling activity was completely dependent on COX-1, but while exogenous ROS was able to elicit a COX-dependent CCA contractile response, in-bath ROS manipulating compounds were found to be without effect on ACh-stimulated CCA EDCF signaling activity. Furthermore, biochemical analysis revealed that aging was not associated with a change in tissue (liver and vascular) GSH content or ROS accumulation. Chronic in vivo BSO treatment was effective in depleting tissue GSH content and increasing ROS accumulation, to a similar extent, in both Adult and Aging SD rats. However, regardless of age, neither ACh-stimulated NO-mediated EDRF signaling activity nor COX-mediated EDCF signaling activity were affected by these BSO-induced perturbations. Conclusions and Perspective: In the CCA of animals at the early pathological stages of either essential hypertension (young adult SHR) or normotensive aging (Aging SD rats), endothelial vasomotor dysfunction can be caused solely by over-active EDCF signaling, apparently disconnected from changes in NO bioavailability or oxidative stress. While NO and ROS may act, respectively, as negative and positive modulators of the established COX-PG-TP receptor-RhoA-ROCK cell-signaling axis mediating endothelium-dependent contractile activity, these factors do not appear to be essential to the mechanism(s) underlying the development of over-active EDCF signaling. Further elucidation of the cellular-molecular causes of over-active EDCF signaling, and its patho-biological consequences, in the SHR-WKY and Adult-Aging SD rat CCA models of EDCF activity established and hemodynamically characterized in this thesis, may help to identify new or more effective targets to be used in prevention or treatment strategies to combat the pathogenesis of CVD.

La rigidité artérielle est considérée comme un facteur de risque important pour le développement du déclin cognitif. Toutefois, les effets précis de la rigidité artérielle sur le cerveau sont peu connus et, à ce jour, aucun modèle animal ne permet d’étudier l’effet isolé de ce facteur sur l’homéostasie cérébrale. Dans cette étude, nous avons développé un nouveau modèle de rigidité artérielle qui se base sur la calcification de l’artère carotide chez la souris. Au niveau artériel, ce modèle présente une fragmentation de l’élastine, une augmentation de la distribution du collagène et de l’épaisseur intima-média ainsi qu’une diminution de la compliance et de la distensibilité artérielles démontrant la rigidité artérielle. De plus, le modèle ne présente pas d’augmentation de pression artérielle ni de changement de rayon du lumen indiquant une absence d’hypoperfusion globale et d’anévrisme. Au niveau cérébral, les résultats montrent que la rigidité artérielle induit une augmentation de la pulsatilité du flux sanguin cérébral menant ainsi à une augmentation du stress oxydatif. Ce dernier induit une inflammation cérébrale, détectée par l’activation de la microglie et des astrocytes, induisant ultimement une neurodégénérescence. Ces effets sont surtout observés au niveau de l’hippocampe, la région cruciale pour la mémoire et la cognition. Ainsi, cette étude montre que la rigidité artérielle altère l’homéostasie cérébrale et mérite d’être considérée comme une cible potentielle dans la prévention et le traitement des dysfonctions cognitives chez les personnes âgées. / Arterial stiffness is considered as an important risk factor for the development of cognitive decline in the elderly population. However, its precise effects on the brain are unknown and, to date, no animal model allows to study the precise outcome of arterial stiffness on the brain homeostasis. In this study, we developed a new animal model of arterial stiffness based on the calcification of the carotid artery in mice. On the arterial level, this model shows a fragmentation of elastin, increased collagen distribution and intima-media thickness as well as decreased arterial compliance and distensibility, thus fulfilling the major arterial stiffness properties. In addition, this model does not a show an increase in blood pressure or change in arterial lumen radius indicating a lack of global hypoperfusion and aneurysm. Regarding the brain, the results show that arterial stiffness induces an increase in cerebral blood flow pulsatility leading to increased oxidative stress. Oxidative stress induces brain inflammation, detected by the activation of microglia and astrocytes, ultimately leading to neurodegeneration. These effects are particularly observed in the hippocampus, a crucial area for memory and cognition. Thus, this study shows that arterial stiffness alters brain homeostasis and therefore should be considered as a potential therapeutical target for the prevention and treatment of cognitive dysfunction in the elderly.

Orientador: Ligia Yukie Sassaki / Resumo: Biondi, R.B. Fatores relacionados com risco cardiovascular em indivíduos com Doença Inflamatória Intestinal. 2018. 48p. Dissertação (Mestrado). Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, 2018. Introdução: a incidência das doenças inflamatórias intestinais (DII), que compreendem principalmente a doença de Crohn (DC) e a retocolite ulcerativa idiopática (RCUI) aumentou nas últimas décadas. Evidências sugerem que, assim como observado em outras doenças inflamatórias, indivíduos com DII, podem apresentar maior risco de doenças cardiovasculares, uma vez que a inflamação crônica desempenha papel essencial na aterogênese. Objetivo: avaliar o risco cardiovascular de indivíduos com DC e RCUI. Metodologia: estudo transversal conduzido no periodo de abril 2016 a outubro de 2017 com indivíduos portadores de DC e RCUI atendidos no Ambulatório de DII do Hospital das Clínicas da Faculdade de Medicina de Botucatu (HC-FMB), comparado ao grupo controle. Foram avaliados dados como idade, sexo, índice de massa corporal, tabagismo, pressão arterial, atividade da doença, presença de comorbidades e tratamento medicamentoso, grau de espessamento medio-intimal das artérias carótidas (EMIC), presença de placa aterosclerótica nas artérias carótidas, escore de risco framingham (ERF), níveis séricos de proteína C reativa, perfil lipídico e glicemia. Foram utilizado o teste "t" de Student e o teste Mann-Whitney comparação dos grupos. Foram realizadas a regressão logística... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Biondi, R.B. Factors related to cardiovascular risk in individuals with Inflammatory Bowel Disease. 2018. 48p. Dissertation (Master’s). Botucatu Medical School, São Paulo State University, Botucatu, 2018. Introduction: The incidence of inflammatory bowel diseases (IBD), which encompass Crohn’s disease (CD) and ulcerative colitis (UC), has increased over the past decades. Considering that chronic inflammation plays an essential role in atherogenesis, studies have shown IBD may be associated with higher cardiovascular disease risk. Objective: The objective was to assess cardiovascular risk in CD or UC individuals. Methods: This cross-sectional study, conducted between April 2016 and October 2017, included CD or UC outpatients from the IBD outpatient clinic of Botucatu Medical School Hospital compared to a control group. Data collected included age, gender, body mass index, smoking status, arterial blood pressure, disease activity, presence of co-morbidities, ongoing medical treatment, carotid intima media thickness (CIMT), presence of carotid atherosclerotic plaque, Framingham risk score (FRS), serum C-reactive protein, lipid profile and glucose level. Groups were compared using the Student t test and Mann-Whitney test. Multivariate logistic regression or multiple linear regression analyses were performed with significance level at 5%. Results: 52 individuals in IBD group and 37 matched controls were included. In IBD group, 67.3% of the individuals had UC and 32.7% presented CD... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2015-04-17T15:02:56Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1377692 bytes, checksum: 3f9ed1b868827e7be04d2e3b20d643a0 (MD5) Previous issue date: 2011-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The carotid artery calcification (CAC) is one of the most serious and frequent complications occurring in patients with chronic kidney disease. In recent years, the dental literature has warned dentists about the possibility of panoramic radiography to detect these lesions. However, little is known about the reliability of this method in the diagnosis of calcifications. The objective of this study was to evaluate by means of two scientific articles the prevalence of CAC in digital panoramic radiographs (DPR) of patients with chronic kidney failure under hemodialysis treatment and see if this examination can be reliable in the diagnosis of these lesions. The first article analyzed the prevalence of calcifications in the DPR of patients with chronic kidney failure and compared these results with the radiographic findings of a group of healthy patients. Statistical analysis using chi-square test revealed a significant difference (p <0.001) in the prevalence of these lesions among the study groups, since 28% (n = 14) of the radiographs of patients on hemodialysis had pictures of CAC, whereas only 2% (n = 1) radiographs of the control group had these images. The second article verified the reliability of the DPR in the diagnosis of CAC, comparing the results of that examination with ultrasonography (USG). The parameters used for this evaluation were precision, sensitivity, specificity and positive predictive value. The results showed that the panoramic radiograph was 71.43% accurate in diagnosing cases of CAC confirmed by ultrasound, with low sensitivity (37.93%), high specificity (95.12%) and good positive predictive value (84.61%). In addition, the McNemar test revealed a statistically significant difference (p <0.001) between the ability of DPR to diagnose CAC compared to the USG. On the above, we can conclude that patients with chronic kidney failure under hemodialysis treatment are significantly more affected by the CAC that the healthy population and that despite the DPR is not indicated as test of choice to investigate the presence of CAC, it can be a useful tool in the diagnosis of lesions in asymptomatic patients. / A calcificação na artéria carótida (CAC) é uma das complicações mais graves e frequentes que ocorre nos pacientes portadores de doença renal crônica. Nos últimos anos, a literatura odontológica tem alertado os cirurgiões-dentistas quanto à possibilidade de a radiografia panorâmica detectar essas lesões. Entretanto, pouco se sabe a respeito da confiabilidade desse método no diagnóstico dessas calcificações. Assim, o objetivo do presente trabalho foi avaliar por meio de dois artigos científicos a prevalência de CAC nas radiografias panorâmicas digitais (RPD) de doentes renais crônicos sob tratamento de hemodiálise e verificar se esse exame pode ser confiável no diagnóstico dessas lesões. O primeiro artigo analisou a prevalência das calcificações nas RPD de doentes renais crônicos e comparou esse resultado com os achados radiográficos de um grupo de pacientes saudáveis. A análise estatística pelo teste qui-quadrado revelou diferença significativa (p< 0.001) na prevalência dessas lesões entre os grupos avaliados, uma vez que 28% (n= 14) das radiografias dos pacientes que realizavam hemodiálise apresentavam imagens de CAC, enquanto que apenas 2% (n=1) das radiografias do grupo controle possuíam essas imagens. O segundo artigo verificou a confiabilidade da RDP no diagnóstico da CAC, comparando os resultados obtidos nesse exame com os da ultrassonografia (USG). Os parâmetros utilizados para essa avaliação foram a precisão, sensibilidade, especificidade e o valor preditivo positivo. Os resultados mostraram que a radiografia panorâmica foi precisa em diagnosticar 71,43% dos casos de CAC confirmados pela ultrassonografia, apresentando baixa sensibilidade (37.93%), alta especificidade (95.12%) e bom valor preditivo positivo (84.61%). Além disso, o teste de McNemar revelou uma diferença estatisticamente significante (p< 0.001) entre a capacidade de diagnosticar CAC da RPD, quando comparada à USG. Diante do exposto, pode-se concluir que os doentes renais crônicos sob tratamento de hemodiálise são significativamente mais afetados por CAC do que a população saudável e que apesar da RPD não ser indicada como exame de escolha para investigação da presença de CAC, ela pode ser uma ferramenta útil no diagnóstico de lesões em pacientes assintomáticos.