Search results for "Aorta"
showing 10 items of 458 documents
Role of the cyclic AMP-dependent pathway in free radical-induced cholesterol accumulation in vascular smooth muscle cells.
2000
We have previously reported that free radical-treated vascular smooth muscle cells (SMC) lead to cholesterol accumulation in vitro. In the current study, we investigated the effects of oxidative stress on cyclic AMP concentration and cAMP-dependent enzymes involved in cholesterol homeostasis in A7r5 cells. Under our conditions of a mild oxidative stress, namely with no change in cell viability, we found that free radicals, initiated using azobis-amidinopropane dihydrochloride (AAPH), resulted in a dose-dependent decrease in cellular cAMP which was opposed by vitamin E preincubation. Although the addition of adenylate cyclase activators (carbacyclin and forskolin) increased cAMP levels it di…
Aortic Annulus Stabilization Using Internal Rings
2017
The past 20 years have seen the growing range of valve lesion etiologies turn nonvalvular conditions into the primary causes of aortic regurgitation [1]. Valves present relatively small lesions of the leaflets and concomitant dilatation of the ascending aorta with aortic regurgitation that can be explained thanks to our improved knowledge of the functional aortic annulus’ role in valve function. The geometric relations and dynamic behavior of aortic root components have been seen to ensure valve competence when leaflets have no structural lesions [2].
CRT-723 Is the Sporadic Thoracic Aortic Aneurysm the Result of an Inflammatory Process?
2014
Sporadic thoracic aortic aneurysm (S-TAA) is potentially devastating with severe morbidity and mortality. The histopathologic underlying abnormality of both ascending aortic aneurysm and dissection is medial degeneration, a pathological entity initially described as no inflammatory lesions of smooth
Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine
1998
Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine. Myogenic, pressure-induced vasoconstriction may amplify the effects of circulating vasoconstrictors. Through intravital microscopy in cremaster arterioles (31 to 115 μm diameter), the relative contribution of myogenic responses (MR) to norepinephrine (NE)-induced constriction and the inhibitor potency of nitric oxide (NO) or a Ca2+ entry blocker (CEB), felodipine (F), were examined. In 24 anesthetized hamsters, a vessel occluder was placed around the aorta to control cremaster vessel inflow pressure (IP). NE infusion increased blood pressure (by 50 ± 2mm Hg) and induced significant constriction …
Factors Predisposing to Hypertension in Subjects Formerly Born Preterm: Renal Impairment, Arterial Stiffness, Endothelial Dysfunction or Something E…
2020
: Subjects formerly born preterm subsequently develop arterial - particularly isolated systolic- hypertension more frequently than their peers born at term. : Numerous factors may influence this predisposition, including an incomplete nephrogenesis, implying the presence of kidneys with a reduced number of nephrons and consequent reduction in haematic filtration, increased sodium absorption and activation of renin-angiotensin-aldosterone system, increased arterial rigidity produced by an elastin deficiency previously observed in anatomic specimens of human immature aorta, and reduced endothelial nitric oxide excretion, due to high blood levels of ADMA, a strong direct inhibitor of nitric o…
Evidence, Lack of Evidence, Controversy, and Debate in the Provision and Performance of the Surgery of Acute Type A Aortic Dissection
2011
Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or t…
Druckentlastung im Aneurysmasack nach endovaskulärer Therapie von Aortenaneurysmen*
2000
PURPOSE Stent grafting of aortic aneurysms should result in relief of pressure within the excluded aneurysmal sac, however confirming data are not available. This study evaluates the intra-extraluminal pressure translation and translation of maximum pressure increase (dp/dtmax) into the excluded aneurysmal sac after endovascular treatment of experimental aortic aneurysms. MATERIALS AND METHODS Experimental autologous aneurysms were created surgically using a patch from the sheath of the rectus abdominis muscle in 12 mongrel dogs. After 12 weeks reconvalescence, endovascular treatment was performed viafemoral access using dacron-covered nitinol stents. Spiral CT and angiography were performe…
Morphologische und funktionelle Evaluation pulmonaler Gefäßanomalien mittels schneller MR-Techniken
2002
Purpose: To evaluate breath-hold MR techniques for morphologic and functional assessment of vascular abnormalities of the pulmonary vasculature. Patients and Methods: 13 patients aged 11 to 60 years with different vascular abnormalities of the pulmonary vasculature (5 patients with 16 arteriovenous malformations, 8 patients with partial anomalous pulmonary venous return) underwent MR imaging at 1.5 T. For morphological assessment, a contrast-enhanced 3D MR angiography (ce-MRA) was performed after a timing run. Segmented cine- and velocity-encoded GRE sequences were used for delineation of associated cardiac septal defects and for determination of systemic left-to-right or intrapulmonary shu…
Patient-specific computational evaluation of stiffness distribution in ascending thoracic aortic aneurysm
2021
Quantifying local aortic stiffness properties in vivo is acknowledged as essential to assess the severity of an ascending thoracic aortic aneurysm (ATAA). Recently, the LESI (local extensional stiffness identification) methodology has been established to quantify non-invasively local stiffness properties of ATAAs using electrocardiographic-gated computed tomography (ECG-gated CT) scans. The aim of the current study was to determine the most sensitive markers of local ATAA stiffness estimation with the hypothesis that direct measures of local ATAA stiffness could better detect the high-risk patients. A cohort of 30 patients (12 BAV and 18 TAV) referred for aortic size evaluation by ECG-gated…
Bifidobacterium pseudocatenulatum CECT 7765 supplementation restores altered vascular function in an experimental model of obese mice
2017
Aims. Bifidobacterium pseudocatenulatum CECT 7765 improves metabolic and immunological altered functions in high fat fed mice, however little is known about the effects of potential probiotics on vascular reactivity. The aim of the present study was to investigate the effects of a potential probiotic strain, Bifidobacterium pseudocatenulatum CECT 7765, on vascular response in obese mice. Methods. Aorta samples were obtained from mice, which were divided into three groups: a control group, receiving a standard diet; an obese group, receiving a high-fat diet; and an obese group receiving high-fat diet and a daily dose of B. pseudocatenulatum CECT 7765 by oral gavage. Aortic rings were suspend…