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A study of blood flow in normal and dilated aortaDeep, Debanjan 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Atherosclerotic lesions of human beings are common diagnosed in regions of arte- rial branching and curvature. The prevalence of atherosclerosis is usually associated with hardening and ballooning of aortic wall surfaces because of narrowing of flow path by the deposition of fatty materials, platelets and influx of plasma through in- timal wall of Aorta. High Wall Shear Stress (WSS) is proved to be the main cause behind all these aortic diseases by physicians and researchers. Due to the fact that the atherosclerotic regions are associated with complex blood flow patterns, it has believed that hemodynamics and fluid-structure interaction play important roles in regulating atherogenesis. As one of the most complex flow situations found in cardio- vascular system due to the strong curvature effects, irregular geometry, tapering and branching, and twisting, theoretical prediction and in vivo quantitative experimental data regarding to the complex blood flow dynamics are substantial paucity. In recent years, computational fluid dynamics (CFD) has emerged as a popular research tool to study the characteristics of aortic flow and aim to enhance the understanding of the underlying physics behind arteriosclerosis. In this research, we study the hemo- dynamics and flow-vessel interaction in patient specific normal (healthy) and dilated (diseased) aortas using Ansys-Fluent and Ansys-Workbench. The computation con- sists of three parts: segmentation of arterial geometry for the CFD simulation from computed tomography (CT) scanning data using MIMICS; finite volume simulation of hemodynamics of steady and pulsatile flow using Ansys-Fluent; an attempt to perform the Fluid Structure Simulation of the normal aorta using Ansys-Workbench. Instead of neglecting the branching or smoothing out the wall for simplification as a
lot of similar computation in literature, we use the exact aortic geometry. Segmen- tation from real time CT images from two patients, one young and another old to represent healthy and diseased aorta respectively, is on MIMICS. The MIMICS seg- mentation operation includes: first cropping the required part of aorta from CT dicom data of the whole chest, masking of the aorta from coronal, axial and saggital views of the same to extract the exact 3D geometry of the aorta. Next step was to perform surface improvement using MIMICS 3-matic module to repair for holes, noise shells and overlapping triangles to create a good quality surface of the geometry. A hexahe- dral volume mesh was created in T-Grid. Since T-grid cannot recognize the geometry format created by MIMICS 3-matic; the required step geometry file was created in Pro-Engineer. After the meshing operation is performed, the mesh is exported to Ansys Fluent to perform the required fluid simulation imposing adequate boundary conditions accordingly. Two types of study are performed for hemodynamics. First is a steady flow driven by specified parabolic velocity at inlet. We captured the flow feature such as skewness of velocity around the aortic arch regions and vortices pairs, which are in good agreement with open data in literature. Second is a pulsatile flow. Two pulsatile velocity profiles are imposed at the inlet of healthy and diseased aorta respectively. The pulsatile analysis was accomplished for peak systolic, mid systolic and diastolic phase of the entire cardiac cycle. During peak systole and mid-systole, high WSS was found at the aortic branch roots and arch regions and diastole resulted in flow reversals and low WSS values due to small aortic inflow. In brief, areas of sudden geometry change, i.e. the branch roots and irregular surfaces of the geom- etry experience more WSS. Also it was found that dilated aorta has more sporadic nature of WSS in different regions than normal aorta which displays a more uniform WSS distribution all over the aorta surface. Fluid-Structure Interaction simulation is performed on Ansys-WorkBench through the coupling of fluid dynamics and solid mechanics. Focus is on the maximum displacement and equivalent stress to find out the future failure regions for the peak velocity of the cardiac cycle.
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Estudo crítico da anatomia arterial do retalho vascularizado pela artéria perfurante muscular da artéria epigástrica inferior / Viability of utilizing the pectoralis major perforator muscular vessels as a recipient pedicle in immediate and late breast reconstruction with microsurgeryMunhoz, Alexandre Mendonça 19 July 2004 (has links)
A utilização dos retalhos músculo-cutâneos na cirurgia plástica possibilitou grande avanço nas técnicas de reconstrução. Apesar de atualmente se apresentarem como técnica conhecida e reprodutível, existem ainda limitações quanto à morbidade na área doadora advinda da ressecção muscular. O desenvolvimento dos retalhos perfurantes e a aplicação clínica do retalho vascularizado na artéria perfurante muscular da artéria epigástrica inferior (DIEP) possibilitaram nova opção terapêutica em decorrência da completa preservação músculo-aponeurótica. Apesar dos benefícios funcionais em relação aos tradicionais retalhos músculo-cutâneos, o retalho DIEP exibe limitações como o tempo cirúrgico prolongado, a dificuldade técnica e o risco de lesão da artéria perfurante no trajeto intramuscular, todos decorrentes do calibre reduzido das artérias e da variabilidade anatômica. Embora a anatomia do músculo reto do abdome tenha sido exaustivamente estudada, escassas e imprecisas são as informações sobre a distribuição das artérias perfurantes, o trajeto intramuscular e as características do pedículo arterial. No presente estudo, a distribuição, o trajeto intramuscular e as dimensões do pedículo do retalho DIEP foram estudados em 15 cadáveres frescos não formolizados (30 retalhos) por técnica de coloração com tinta azul látex e posterior dissecção. Constatou-se 6,3 artérias perfurantes por retalho, sendo que a maior parte das artérias de médio e grande calibre localizavam-se na região lateral do músculo reto do abdome. Na análise do trajeto intramuscular foram classificadas de artérias com trajeto retilíneo, aquelas localizadas exclusivamente no septo muscular e sua dissecção foi realizada sem secção das fibras musculares. No trajeto oblíquo, se evidenciou mais de um septo muscular e houve a necessidade de se realizar a secção muscular. As artérias perfurantes da região lateral apresentaram trajeto retilíneo em maior número quando comparadas às artérias da região medial do músculo reto do abdome. Na maioria das dissecções, a artéria epigástrica inferior mostrou dois ramos principais sendo o calibre do ramo lateral maior ao do ramo medial. A maioria das artérias perfurantes de médio e grande calibres apresentaram origem no ramo lateral dominante da artéria epigástrica inferior. As artérias perfurantes e o pedículo arterial do retalho revelaram comprimento médio de 5,3 e 15,7 cm respectivamente. O pedículo arterial com a artéria perfurante proveniente da região medial apresentou comprimento maior do que o pedículo que continha a artéria proveniente da região lateral. O presente estudo permitiu-nos concluir que a maior concentração de artérias perfurantes de maior calibre e a presença do trajeto retilíneo na região lateral do músculo reto do abdome, constituíram parâmetros anatômicos importantes no planejamento da técnica. As conclusões obtidas reforçam a relevância dos estudos anatômicos na programação da reconstrução com retalhos vascularizados por artérias perfurantes. / The introduction of musculocutaneous flaps in plastic surgery has resulted in a great step forward in reconstructive procedures. In spite of their well-known and reproducible technique, their use is limited by morbidity in the donor area resulting from muscle resection. The development of perforator flap and the clinical application of the deep inferior epigastric flap (DIEP) has provided a new therapeutic option resulting from complete muscle-aponeurotic preservation. Despite the functional benefits achieved in comparison to traditional musculocutaneous flaps, the DIEP flap has limitations. The latter include prolonged operative time, technical difficulty and the risk of injury to the perforating artery in the intramuscular pathway. These factors result from reduced diameter of the arteries and to anatomic variation. Although anatomy of the rectus abdominus muscle has already been studied, information regarding distribution of the perforator arteries, intramuscular pathway, and characteristics of the arterial pedicle is lacking and inaccurate. In this thesis, the distribution, intramuscular pathway and pedicle size of the DIEP flap were studied in 15 fresh cadavers. Thirty flaps were analyzed by staining with blue latex dye and subsequent dissection. An average of 6.3 perforator arteries per flap were observed, and the major concentration of medium and large diameter arteries in the lateral region of the rectus muscle. The intramuscular pathway analysis classified the arteries as rectilinear, those located solely in the muscle septum and their dissection was performed without muscle fibers section. In the oblique pathway, not a single septum was observed and muscle section was necessary. A larger number of the perforator arteries of the lateral region presented a rectilinear path compared to the arteries of the medial region. In the majority of dissections, the inferior epigastric artery exhibited two main branches with the lateral branch diameter greater than that of the medial branch. The majority of the perforator arteries of medium and large diameter originated in the dominant lateral branch of the IEA. The perforator arteries and the arterial pedicle of the flap displayed a mean length of 5.3 and 15.7cm respectively. The arterial pedicle presenting the perforator artery originating from the medial region was longer than the pedicle containing the artery originating from the lateral region. The major concentration of perforator arteries of larger diameter besides being rectilinear in the lateral region of the rectus muscle establishes important parameters for technical planning. The results obtained in this study emphasize the importance of the anatomic studies in planning reconstructions with perforator flaps.
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Restrição proteica materna e alteração do desenvolvimento das artérias coronárias em camundongos / Maternal protein restriction and modification of the development of coronary arteries in miceGeraldo de Oliveira Silva Junior 14 October 2011 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O desenvolvimento da programação fetal é considerado um importante fator de risco para doenças não-transmissíveis da vida adulta, incluindo doença cardíaca coronariana. Com o objetivo de investigar a associação entre nutrição materna e o desenvolvimento das artérias coronárias (AC) em embriões de camundongos estadiados; embriões de camundongos C57BL/6 nos estádios de 16-23 foram retirados de mães alimentadas com dietas de proteína normal (NP) ou de baixa proteína (LP), e as AC foram estudadas. Embora os embriões LP possuam massa corporal menor, entretanto tinham taxas de crescimento cardíaco maior, quando comparados com os embriões NP. O Plexo subepicárdico foi observado no início do período pós-somítico (estádio 16) de embriões NP, enquanto que nos embriões LP apenas no estádio 17 (P <0,01), persistindo até o estádio 18 (P <0,01). As artérias coronárias foram detectadas inicialmente no estádio18 dos embriões NP, já nos embriões LP foram encontradas a partir do estádio 19 (P <0,01). Núcleos apoptóticos foram observados em torno do anel aórtico peritruncal no estádio 18 em embriões NP e LP. Células FLK1+ (Fetal Liver Kinase 1 = VEGFr2 = Vascular Endothelial Growth Factor Receptor 2) apresentaram uma distribuição homogênea nos embriões NP já no estádio 18, enquanto uma distribuição semelhante nos embriões LP foi visto apenas nos estádios 22 e 23. A restrição proteica materna em camundongos leva a um atraso no crescimento do coração no período embrionário modificando o desenvolvimento do plexo peritruncal subepicárdica e diminuindo a taxa de apoptose na região do futuro orifício coronariano. / Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease (CHD). Aiming to investigate the association between maternal nutrition and the development of the coronary arteries (CA) in staged mice embryos, C57BL/6 mice embryos from stages 16 to 23 were taken from mothers fed a normal protein (NP) or low protein (LP) diet, and the CA were studied. Although the LP embryos had lower masses, they had faster heart growth rates when compared to the NP embryos. The subepicardial plexuses were observed earlier in the NP embryos (stage 20) than in the LP ones (stage 22) (P<0.01). Apoptotic nuclei were seen around the aortic peritruncal ring beginning at stage 18 in the NP and LP embryos. FLK1+ (fetal liver kinase 1 = VEGFr2 or vascular endothelial growth factor receptor 2) cells had a homogeneous distribution in the NP embryos as early as stage 18, whereas a similar distribution in the LP embryos was only seen at stages 22 and 23. Maternal protein restriction in mice leads to a delay in the growth of the heart in the embryonic period modifying the development of the subepicardial peritruncal plexus and the apoptosis in the future coronary orifice region.
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Restrição proteica materna e alteração do desenvolvimento das artérias coronárias em camundongos / Maternal protein restriction and modification of the development of coronary arteries in miceGeraldo de Oliveira Silva Junior 14 October 2011 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O desenvolvimento da programação fetal é considerado um importante fator de risco para doenças não-transmissíveis da vida adulta, incluindo doença cardíaca coronariana. Com o objetivo de investigar a associação entre nutrição materna e o desenvolvimento das artérias coronárias (AC) em embriões de camundongos estadiados; embriões de camundongos C57BL/6 nos estádios de 16-23 foram retirados de mães alimentadas com dietas de proteína normal (NP) ou de baixa proteína (LP), e as AC foram estudadas. Embora os embriões LP possuam massa corporal menor, entretanto tinham taxas de crescimento cardíaco maior, quando comparados com os embriões NP. O Plexo subepicárdico foi observado no início do período pós-somítico (estádio 16) de embriões NP, enquanto que nos embriões LP apenas no estádio 17 (P <0,01), persistindo até o estádio 18 (P <0,01). As artérias coronárias foram detectadas inicialmente no estádio18 dos embriões NP, já nos embriões LP foram encontradas a partir do estádio 19 (P <0,01). Núcleos apoptóticos foram observados em torno do anel aórtico peritruncal no estádio 18 em embriões NP e LP. Células FLK1+ (Fetal Liver Kinase 1 = VEGFr2 = Vascular Endothelial Growth Factor Receptor 2) apresentaram uma distribuição homogênea nos embriões NP já no estádio 18, enquanto uma distribuição semelhante nos embriões LP foi visto apenas nos estádios 22 e 23. A restrição proteica materna em camundongos leva a um atraso no crescimento do coração no período embrionário modificando o desenvolvimento do plexo peritruncal subepicárdica e diminuindo a taxa de apoptose na região do futuro orifício coronariano. / Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease (CHD). Aiming to investigate the association between maternal nutrition and the development of the coronary arteries (CA) in staged mice embryos, C57BL/6 mice embryos from stages 16 to 23 were taken from mothers fed a normal protein (NP) or low protein (LP) diet, and the CA were studied. Although the LP embryos had lower masses, they had faster heart growth rates when compared to the NP embryos. The subepicardial plexuses were observed earlier in the NP embryos (stage 20) than in the LP ones (stage 22) (P<0.01). Apoptotic nuclei were seen around the aortic peritruncal ring beginning at stage 18 in the NP and LP embryos. FLK1+ (fetal liver kinase 1 = VEGFr2 or vascular endothelial growth factor receptor 2) cells had a homogeneous distribution in the NP embryos as early as stage 18, whereas a similar distribution in the LP embryos was only seen at stages 22 and 23. Maternal protein restriction in mice leads to a delay in the growth of the heart in the embryonic period modifying the development of the subepicardial peritruncal plexus and the apoptosis in the future coronary orifice region.
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Estudo crítico da anatomia arterial do retalho vascularizado pela artéria perfurante muscular da artéria epigástrica inferior / Viability of utilizing the pectoralis major perforator muscular vessels as a recipient pedicle in immediate and late breast reconstruction with microsurgeryAlexandre Mendonça Munhoz 19 July 2004 (has links)
A utilização dos retalhos músculo-cutâneos na cirurgia plástica possibilitou grande avanço nas técnicas de reconstrução. Apesar de atualmente se apresentarem como técnica conhecida e reprodutível, existem ainda limitações quanto à morbidade na área doadora advinda da ressecção muscular. O desenvolvimento dos retalhos perfurantes e a aplicação clínica do retalho vascularizado na artéria perfurante muscular da artéria epigástrica inferior (DIEP) possibilitaram nova opção terapêutica em decorrência da completa preservação músculo-aponeurótica. Apesar dos benefícios funcionais em relação aos tradicionais retalhos músculo-cutâneos, o retalho DIEP exibe limitações como o tempo cirúrgico prolongado, a dificuldade técnica e o risco de lesão da artéria perfurante no trajeto intramuscular, todos decorrentes do calibre reduzido das artérias e da variabilidade anatômica. Embora a anatomia do músculo reto do abdome tenha sido exaustivamente estudada, escassas e imprecisas são as informações sobre a distribuição das artérias perfurantes, o trajeto intramuscular e as características do pedículo arterial. No presente estudo, a distribuição, o trajeto intramuscular e as dimensões do pedículo do retalho DIEP foram estudados em 15 cadáveres frescos não formolizados (30 retalhos) por técnica de coloração com tinta azul látex e posterior dissecção. Constatou-se 6,3 artérias perfurantes por retalho, sendo que a maior parte das artérias de médio e grande calibre localizavam-se na região lateral do músculo reto do abdome. Na análise do trajeto intramuscular foram classificadas de artérias com trajeto retilíneo, aquelas localizadas exclusivamente no septo muscular e sua dissecção foi realizada sem secção das fibras musculares. No trajeto oblíquo, se evidenciou mais de um septo muscular e houve a necessidade de se realizar a secção muscular. As artérias perfurantes da região lateral apresentaram trajeto retilíneo em maior número quando comparadas às artérias da região medial do músculo reto do abdome. Na maioria das dissecções, a artéria epigástrica inferior mostrou dois ramos principais sendo o calibre do ramo lateral maior ao do ramo medial. A maioria das artérias perfurantes de médio e grande calibres apresentaram origem no ramo lateral dominante da artéria epigástrica inferior. As artérias perfurantes e o pedículo arterial do retalho revelaram comprimento médio de 5,3 e 15,7 cm respectivamente. O pedículo arterial com a artéria perfurante proveniente da região medial apresentou comprimento maior do que o pedículo que continha a artéria proveniente da região lateral. O presente estudo permitiu-nos concluir que a maior concentração de artérias perfurantes de maior calibre e a presença do trajeto retilíneo na região lateral do músculo reto do abdome, constituíram parâmetros anatômicos importantes no planejamento da técnica. As conclusões obtidas reforçam a relevância dos estudos anatômicos na programação da reconstrução com retalhos vascularizados por artérias perfurantes. / The introduction of musculocutaneous flaps in plastic surgery has resulted in a great step forward in reconstructive procedures. In spite of their well-known and reproducible technique, their use is limited by morbidity in the donor area resulting from muscle resection. The development of perforator flap and the clinical application of the deep inferior epigastric flap (DIEP) has provided a new therapeutic option resulting from complete muscle-aponeurotic preservation. Despite the functional benefits achieved in comparison to traditional musculocutaneous flaps, the DIEP flap has limitations. The latter include prolonged operative time, technical difficulty and the risk of injury to the perforating artery in the intramuscular pathway. These factors result from reduced diameter of the arteries and to anatomic variation. Although anatomy of the rectus abdominus muscle has already been studied, information regarding distribution of the perforator arteries, intramuscular pathway, and characteristics of the arterial pedicle is lacking and inaccurate. In this thesis, the distribution, intramuscular pathway and pedicle size of the DIEP flap were studied in 15 fresh cadavers. Thirty flaps were analyzed by staining with blue latex dye and subsequent dissection. An average of 6.3 perforator arteries per flap were observed, and the major concentration of medium and large diameter arteries in the lateral region of the rectus muscle. The intramuscular pathway analysis classified the arteries as rectilinear, those located solely in the muscle septum and their dissection was performed without muscle fibers section. In the oblique pathway, not a single septum was observed and muscle section was necessary. A larger number of the perforator arteries of the lateral region presented a rectilinear path compared to the arteries of the medial region. In the majority of dissections, the inferior epigastric artery exhibited two main branches with the lateral branch diameter greater than that of the medial branch. The majority of the perforator arteries of medium and large diameter originated in the dominant lateral branch of the IEA. The perforator arteries and the arterial pedicle of the flap displayed a mean length of 5.3 and 15.7cm respectively. The arterial pedicle presenting the perforator artery originating from the medial region was longer than the pedicle containing the artery originating from the lateral region. The major concentration of perforator arteries of larger diameter besides being rectilinear in the lateral region of the rectus muscle establishes important parameters for technical planning. The results obtained in this study emphasize the importance of the anatomic studies in planning reconstructions with perforator flaps.
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An assessment of coronary artery calcification, using the calcium scoring technique, in an asymptomatic Indian population in Durban, KwaZulu-NatalMoodley, Karanigie January 2008 (has links)
Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2008. xxi, 146 leaves, Appendices A-S / The main aim of this study, was to assess the prevalence of coronary artery
calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years.
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Kepenų arterijų anatominiai variantai ir jų įtaka viršutinės pasaito arterijos hemodinamikai / Anatomical variants of the hepatic arteries and their influence on superior mesenteric artery hemodynamicsSamuilis, Artūras 02 May 2011 (has links)
Kepenų arterijų anatominiai variantai yra dažni. Viena dažniausių aberantinių (netipiškai atsišakojančių) kepenų arterijų atsišakojimo vietų yra viršutinė pasaito arterija. Pastarosios arterijos kraujotaka yra įtakojama daugybės fiziologinių ir patologinių veiksnių. Literatūroje taip pat aprašyti pavieniai atvejai apie iš viršutinės pasaito arterijos atsišakojančios aberantinės kepenų arterijos įtaką viršutinės pasaito arterijos hemodinamikai, tačiau didesnės apimties įrodymais pagrįstų tyrimų šioje srityje iki šiol nebuvo atlikta. Todėl šio tyrimo tikslas buvo įvertinti, ar aberantinė kepenų arterija, atsišakojanti iš viršutinės pasaito arterijos, reikšmingai įtakoja pastarosios kraujagyslės hemodinamiką.
Šiame tyrime kompiuterinės tomografijos angiografijos pagalba įvertinti kepenų arterijų anatominiai variantai, atrinkti pacientai doplerio ultragarso tyrimams. Pastaruoju metodu tirta viršutinės pasaito arterijos kraujotaka pacientams, kurių vieni turėjo aberantinę kepenų arteriją, atsišakojančią iš viršutinės pasaito arterijos, o kiti turėjo įprastą kepenų arterijų anatomiją. Vertinta aberantinės kepenų arterijos, atsišakojančios iš viršutinės pasaito arterijos, įtaka pastarosios arterijos hemodinamikai (rezistentiškumui).
Remiantis tyrimo duomenimis nustatyta, kad kepenų arterijų anatominiai variantai yra dažni. Aberantinė kepenų arterija, atsišakojanti iš viršutinės pasaito arterijos, reikšmingai mažina pastarosios arterijos rezistentiškumą. Pateiktos praktinės... [toliau žr. visą tekstą] / Anatomical variants of hepatic arteries are frequent. One of the most common origins of aberrant (atypically branching) hepatic arteries is superior mesenteric artery. Many physiologic and pathologic features influence hemodynamics of the latter artery. There were some sporadic cases in literature about the influence of aberrant hepatic artery arising from superior mesenteric artery to the hemodynamics of the latter artery, but no evidence based large extent studies were performed. Therefore the aim of this study was to evaluate how significant the aberrant hepatic artery branching from the superior mesenteric artery influences the hemodynamics of superior mesenteric artery.
Anatomical variants of the hepatic arteries were evaluated by computed tomography angiography also the candidates for Doppler ultrasound were selected. Doppler ultrasound was used to evaluate the hemodynamics of the superior mesenteric artery in patients with aberrant hepatic artery arising from the superior mesenteric artery and in those with typical hepatic artery anatomy. The influence of the aberrant hepatic artery arising from superior mesenteric artery to the hemodynamics (resistance) of the superior mesenteric artery was assessed.
The results of the investigation show that anatomical variants of the hepatic arteries are frequent. The aberrant hepatic artery arising from superior mesenteric artery significantly lowers resistance of the superior mesenteric artery. Practical recommendations were set... [to full text]
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Effet de l’atorvastatine sur la dysfonction endothéliale des artères coronaires épicardiques associée à l’hypertrophie ventriculaire gauche dans un modèle porcinForcillo, Jessica 08 1900 (has links)
Effet de l’atorvastatine sur la dysfonction endothéliale des artères coronaires épicardiques associée à l’hypertrophie ventriculaire gauche dans un modèle porcin
Forcillo J, Aubin MC, Horn A, Shi YF, Carrier M, Tardif JC, Perrault LP
Introduction: L’atorvastatine par ses effets pléiotropiques pourrait limiter la dysfonction endothéliale associée au développement de l’HVG.
Méthodologie : Un cerclage de l’aorte ascendante pendant 2 mois entraîne le développement d’HVG et les groupes ont été traités avec atorvastatine 40 ou 80 mg de 60 à 90 jours. L’HVG est confirmée par échographie. La réactivité vasculaire est évaluée en chambres d’organe, la fonction endothéliale par la quantification de la GMPc et des nitrites/nitrates plasmatiques. Le stress oxydant est mesuré par les niveaux d’ANG II et de la carbonylation des protéines.
Résultats : Après 60 et 90 j de cerclage, l’HVG est observée chez tous ces groupes. Les courbes concentrations-réponse des anneaux des artères coronaires épicardiques des groupes traités avec l’atorvastatine 40 et 80 mg pour 30 et 60 jours n’ont démontré aucune amélioration des relaxations dépendantes de l’endothélium. Une exacerbation significative de la dysfonction endothéliale a été observée. Les niveaux vasculaires de GMPc sont significativement diminués dans le groupe sans cerclage traité 60 d et ceux d’ANG II sont fortement augmentés chez ce dernier groupe ainsi que le groupe traité avec 80 mg pour 30 jours par rapport aux contrôles. L’expression de la carbonylation des protéines est augmentée dans le groupe témoin traité avec atorvastatine 80 mg, reflétant une augmentation du stress oxydant.
Conclusion : L’administration d’atorvastatine ne prévient pas le développement de l’HVG ni la dysfonction endothéliale dans notre modèle. Au contraire l’atorvastatine à haute dose a un effet toxique sur les artères coronaires épicardiques en augmentant la dysfonction endothéliale. / Effect of atorvastatin on endothelial dysfunction of epicardial coronary arteries associated with left ventricular hypertrophy in a porcine model.
Forcillo J, Aubin MC, Horn A, Shi YF, Carrier M, Tardif JC, Perrault LP
Background: Atorvastatin, through pleiotropic effects, may prevent or reverse the endothelial dysfunction associated with LVH. Methods: After performing a banding of the ascending aorta for 2 months leading to the development of LVH, groups have been treated with atorvastatin 40 or 80 mg for 60 and 90 day periods. LVH was evaluated by echocardiographic studies. Vascular reactivity studies were performed in organ chambers. In vitro endothelial function was evaluated by plasmatic nitrites/nitrates, the degradations products of nitric oxide, and cGMP quantification. To quantify and qualify oxidative stress, protein carbonyl and angiotensin II levels were assessed.
Results: Following 60 and 90 days of aortic banding, the development of LVH was observed in these groups. Concentration-response curves from rings of epicardial coronary arteries of groups treated with atorvastatin 40 and 80 mg for 30 and 60 days showed a significant decrease of endothelium-dependent relaxations with worsening of the endothelial dysfunction. Levels of cGMP were significantly decreased in the 60 days treated sham group and levels of ANG II were increased in the latter and also in the 90 days banded groups treated with 80 mg for 30 days compared to controls. The expression of protein carbonyl increased in the sham group treated with atorvastatin 80 mg compatible with an increase in oxidative stress.
Conclusion: The administration of atorvastatin does not limit the development of LVH nor the endothelial dysfunction in our model. On the opposite, atorvastatin at a high dose has a toxic effect on epicardial coronary arteries by exacerbating the endothelial dysfunction.
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An assessment of coronary artery calcification, using the calcium scoring technique, in an asymptomatic Indian population in Durban, KwaZulu-NatalMoodley, Karanigie January 2008 (has links)
Thesis submitted in fulfilment of the requirements of the Master's Degree in technology: Radiography, Durban University of Technology, 2008. / The main aim of this study, was to assess the prevalence of coronary artery
calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years. / M
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Pohybová aktivita pacientů po Senningově korekci transpozice velkých tepen / Physical activity in patients after Senning procedure for transposition of the great arteriesPřádová, Kateřina January 2014 (has links)
Background: The transposition of the great arteries (TGA) is a common congenital heart disease. In the 1980s the Senning procedure was the major approach in correction of TGA in the Czech Republic. Although the most recent operation technique called arterial switch is the method of first choice nowadays, patients after Senning procedure are still visiting the cardiology centre. The aim of this thesis was to evaluate the relationship between the selected parameters from the exercise test and quantified level of physical activity (PA) in these individuals. Methods: 71 patients after the Senning procedure underwent a cardiopulmonary exercise test and they completed an international physical activity questionnaire (IPAQ). Selected data from the questionnaire and the exercise test were evaluated by Pearson correlation coefficient (p < 0,05). Results: 56 patients meet criteria of IPAQ (71 % male, n = 40) and were included in the study. Total PA averaged 6576 ± 5204 MET-minutes/week (median 5271 MET-minutes/week) and 70 % individuals meet criteria for high level of PA according to IPAQ data. Peak VO2 averaged 31,9 ± 6,6 ml/min/kg, maximum heart rate was 177 ± 18,6 beats per minute, the highest work load was 2,7 ± 0,8 W/kg and systolic blood pressure was 185 ± 24,0 mmHg. We found statistically significant...
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