Search results for "vessels"
showing 10 items of 348 documents
Critical single proximal left arterial descending coronary artery stenosis to mimic chronic myocardial ischemia: a new model induced by minimal invas…
2008
<i>Background/Aims:</i> The present report examines a new pig model for progressive induction of high-grade stenosis, for the study of chronic myocardial ischemia and the dynamics of collateral vessel growth. <i>Methods:</i> Thirty-nine Landrace pigs were instrumented with a novel experimental stent (GVD stent) in the left anterior descending coronary artery. Eight animals underwent transthoracic echocardiography at rest and under low-dose dobutamine. Seven animals were examined by nuclear PET and SPECT analysis. Epi-, mid- and endocardial fibrosis and the numbers of arterial vessels were examined by histology. <i>Results:</i> Functional analysis showed a…
Defining a reduced volume zone for the simulation of burst test on a composite pressure vessels
2018
International audience; A Fibre-Break Model (FBM) developed at Mines ParisTech can predict the burst pressure of high pressure composite vessels. This model uses random values of fibre strength at each Gauss point of the considered vessels meshed with finite element (FE). However, previous studies has determined the optimum FEs to be used on real-scale structures (0.1 mm x 0.1 mm x 8 mm). A simple calculation shows that, on a real-scale pressure vessel, this induces a gigantic number of FEs, hence the extensive computation time. To overcome this problem, the integral range method is proposed to find a reduced volume zone of the vessels, on which an equivalent calculation can be made and giv…
Semi-automated evaluation tool for retinal vasculopathy.
2009
The ocular fundus is the only area of human body where vascular system is visible using relatively simple instrumentation. Furthermore, there is medical suggestive evidence of a direct relationship between certain measures of vascular characteristics in the ocular fundus (arteriolar and venular calibers and focal arteriolar narrowing) and cardiovascular diseases. In order to establish such relationship on sound statistical basis a method must be provided to measure the needed values in an easy, yet precise and repeatable way. This paper presents a system to assist physicians in signaling and storing the data associated to signs of vascular deterioration and vascular calibers in non-mydriati…
Response by Meneveau and Ecarnot to Letter Regarding Article, “Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention…
2017
We read with interest the letters by Vallurupalli and Uretsky and also Dr Nadir relating to the results of the DOCTORS study (Does Optical Coherence Tomography Optimize Results of Stenting).1 We thank the authors for their insightful remarks. Vallurupalli and Uretsky raise an interesting point when they underline that a prolonged inflation time is superior to a rapid inflation/deflation technique in terms of both stent expansion and apposition. We acknowledge that we did not take stent inflation time into account in the case report form of the DOCTORS study. The arguments put forward by Vallurupalli and Uretsky suggest that this variable should be systematically recorded and reported. Howev…
Long-term outcome of patients with NSTEMI and nonobstructive coronary arteries by different angiographic subtypes
2021
Discordant data have been reported on the prognosis of myocardial infarction with nonobstructive coronary arteries (MINOCA). Moreover, few data are available on the impact of angiographic subtypes. The objectives of this study were to assess the prognostic impact on the long-term follow-up of the diagnosis of MINOCA and its angiographic subtypes.We included 591 consecutive patients with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent coronary angiography. MINOCA was classified according to angiographic findings as smooth coronary arteries, mild irregularities (30% stenosis), and moderate atherosclerosis (30%-49% stenosis). The primary endpoint was a composite of mortal…
Automatic Extraction of Blood Vessels, Bifurcations and End Points in the Retinal Vascular Tree
2008
In this paper we present an effective algorithm for automated extraction of the vascular tree in retinal images, including bifurcations, crossovers and end-points detection. Correct identification of these features in the ocular fundus helps the diagnosis of important systematic diseases, such as diabetes and hypertension. The pre-processing consists in artefacts removal based on anisotropic diffusion filter. Then a matched filter is applied to enhance blood vessels. The filter uses a full adaptive kernel because each vessel has a proper orientation and thickness. The kernel of the filter needs to be rotated for all possible directions. As a consequence, a suitable kernel has been designed …
Artichoke, Cynarin and Cyanidin Downregulate the Expression of Inducible Nitric Oxide Synthase in Human Coronary Smooth Muscle Cells
2014
Artichoke (Cynara scolymus L.) is one of the world’s oldest medicinal plants with multiple health benefits. We have previously shown that artichoke leaf extracts and artichoke flavonoids upregulate the gene expression of endothelial-type nitric oxide synthase (eNOS) in human endothelial cells. Whereas NO produced by the eNOS is a vasoprotective molecule, NO derived from the inducible iNOS plays a pro-inflammatory role in the vasculature. The present study was aimed to investigate the effects of artichoke on iNOS expression in human coronary artery smooth muscle cells (HCASMC). Incubation of HCASMC with a cytokine mixture led to an induction of iNOS mRNA expression. This iNOS induction was c…
Divergent Distribution in Vascular and Avascular Mammalian Retinae Links Neuroglobin to Cellular Respiration
2005
The visual function of the vertebrate retina relies on sufficient supply with oxygen. Neuroglobin is a respiratory protein thought to play an essential role in oxygen homeostasis of neuronal cells. For further understanding of its function, we compared the distribution of neuroglobin and mitochondria in both vascular and avascular mammalian retinae. In the vascular retinae of mouse and rat, oxygen is supplied by the outer choroidal, deep retinal, and inner capillaries. We show that in this type of retina, mitochondria are concentrated in the inner segments of photoreceptor cells, the outer and the inner plexiform layers, and the ganglion cell layer. These are the same regions in which oxyge…
FABC: Retinal Vessel Segmentation Using AdaBoost
2010
This paper presents a method for automated vessel segmentation in retinal images. For each pixel in the field of view of the image, a 41-D feature vector is constructed, encoding information on the local intensity structure, spatial properties, and geometry at multiple scales. An AdaBoost classifier is trained on 789 914 gold standard examples of vessel and nonvessel pixels, then used for classifying previously unseen images. The algorithm was tested on the public digital retinal images for vessel extraction (DRIVE) set, frequently used in the literature and consisting of 40 manually labeled images with gold standard. Results were compared experimentally with those of eight algorithms as we…
Thromboinflammation and Vascular Dysfunction.
2018
Thromboinflammation and vascular dysfunction are inseparably combined with the innate and the adaptive immune response. While the role of this interplay has gained considerable attention in the arena of atherosclerosis/atherothrombosis and in deep vein thrombosis, its role in other forms of vascular disease and risk factors is currently emerging. In this brief review, we will focus on thromboinflammation with regard to cytokine signalling as well as on the novel role of a vascular coagulation-inflammatory circuit in arterial hypertension.Thrombo-Inflammation und vaskuläre Dysfunktion sind untrennbar mit dem angeborenen und dem erworbenen Immunsystem verbunden. Dieses Zusammenspiel wurde im …