Search results for " vascular"
showing 10 items of 945 documents
Bowel resection reduces aortic pulse wave velocity in patients with ulcerative colitis. A longitudinal study.
2020
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Graph-matching based CTA.
2009
Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to subst…
Mechanisms of C-reactive protein-induced blood-brain barrier disruption.
2009
Background and Purpose— Increased mortality after stroke is associated with brain edema formation and high plasma levels of the acute phase reactant C-reactive protein (CRP). The aim of this study was to examine whether CRP directly affects blood–brain barrier stability and to analyze the underlying signaling pathways. Methods— We used a cell coculture model of the blood–brain barrier and the guinea pig isolated whole brain preparation. Results— We could show that CRP at clinically relevant concentrations (10 to 20 μg/mL) causes a disruption of the blood–brain barrier in both approaches. The results of our study further demonstrate CRP-induced activation of surface Fcγ receptors CD16/32 fo…
NADPH Oxidase Accounts for Enhanced Superoxide Production and Impaired Endothelium-Dependent Smooth Muscle Relaxation in BKβ1 −/− Mice
2006
Objective— Nitric oxide (NO)-induced vasorelaxation involves activation of large conductance Ca 2+ -activated K + channels (BK). A regulatory BKβ1 subunit confers Ca 2+ , voltage, and NO/cGMP sensitivity to the BK channel. We investigated whether endothelial function and NO/cGMP signaling is affected by a deletion of the β1-subunit. Methods and Results— Vascular superoxide in BKβ1 −/− was measured using the fluorescent dye hydroethidine and lucigenin-enhanced chemiluminescence. Vascular NO formation was analyzed using electron paramagnetic resonance (EPR), expression of NADPH oxidase subunits, the endothelial NO synthase (eNOS), the soluble guanylyl cyclase (sGC), as well as the activity a…
Nitric oxide synthases: regulation and function
2011
Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodila…
Nitric oxide in the pathogenesis of vascular disease
2000
Nitric oxide (NO) is synthesized by at least three distinct isoforms of NO synthase (NOS). Their substrate and cofactor requirements are very similar. All three isoforms have some implications, physiological or pathophysiological, in the cardiovascular system. The endothelial NOS III is physiologically important for vascular homeostasis, keeping the vasculature dilated, protecting the intima from platelet aggregates and leukocyte adhesion, and preventing smooth muscle proliferation. Central and peripheral neuronal NOS I may also contribute to blood pressure regulation. Vascular disease associated with hypercholesterolaemia, diabetes, and hypertension is characterized by endothelial dysfunct…
PPARγ as an indicator of vascular function in an experimental model of metabolic syndrome in rabbits
2021
Abstract Background and aims Underlying mechanisms associated with vascular dysfunction in metabolic syndrome (MetS) remain unclear and can even vary from one vascular bed to another. Methods In this study, MetS was induced by a high-fat, high-sucrose diet, and after 28 weeks, aorta and renal arteries were removed and used for isometric recording of tension in organ baths, protein expression by Western blot, and histological analysis to assess the presence of atherosclerosis. Results MetS induced a mild hypertension, pre-diabetes, central obesity and dyslipidaemia. Our results indicated that MetS did not change the contractile response in either the aorta or renal artery. Conversely, vasodi…
Inflammation, Endothelial Dysfunction and Arterial Stiffness as Therapeutic Targets in Cardiovascular Medicine
2016
In the last decades, many factors thought to be associated with the atherosclerotic process and cardiovascular events have been studied, and some of these have been shown to correlate with clinical outcome, such as arterial stiffness, endothelial dysfunction and immunoinflammatory markers. Arterial stiffness is an important surrogate marker that describes the capability of an artery to expand and contract in response to pressure changes. It can be assessed with different techniques, such as the evaluation of PWV and AIx. It is related to central systolic pressure and it is an independent predictor of cardiovascular morbidity and mortality in hypertensive patients, type 2 diabetes, end-stage…
Endothelial function testing and cardiovascular disease: focus on peripheral arterial tonometry
2014
During recent decades, a number of methods have been developed to assess endothelial function, contributing to a better understanding of the pathophysiology of cardiovascular disease. Recently, the advent of noninvasive, reproducible techniques for assessment of endothelial function has opened novel possibilities of application in the clinical setting. Peripheral arterial tonometry is a relatively novel, user-friendly technique measuring finger pulse volume amplitude changes induced by reactive hyperemia following 5 minutes of ischemia in the upper limb. Current evidence indicates that this technique has the potential to significantly impact the field of cardiovascular research and preventi…
Pentobarbital-sensitive EDHF comediates ACh-induced arteriolar dilation in the hamster microcirculation
1999
It is unclear to what extent the endothelium-derived hyperpolarizing factor (EDHF) contributes to the control of microcirculatory blood flow in vivo. We analyzed, by intravital microscopy in hamster muscles, the potential role of EDHF along the vascular tree under stimulated (ACh) or basal conditions. Experiments were performed in conscious as well as anesthetized (pentobarbital, urethan) animals. Additionally, cellular effects of the potential EDHF were studied in isolated small arteries. In pentobarbital-anesthetized animals, treatment with N ω-nitro-l-arginine (l-NNA; 30 μmol/l) and indomethacin (3 μmol/l) reduced the dilation in response to 10 μmol/l ACh from 60 ± 6 to 20 ± 4%. This ni…