57 research outputs found

    The bifurcation angle is associated with the progression of saccular aneurysms

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    The role of the bifurcation angle in progression of saccular intracranial aneurysms (sIAs) has been undetermined. We, therefore, assessed the association of bifurcation angles with aneurysm progression using a bifurcation-type aneurysm model in rats and anterior communicating artery aneurysms in a multicenter case-control study. Aneurysm progression was defined as growth by ≥ 1 mm or rupture during observation, and controls as progression-free for 30 days in rats and ≥ 36 months in humans. In the rat model, baseline bifurcation angles were significantly wider in progressive aneurysms than in stable ones. In the case-control study, 27 and 65 patients were enrolled in the progression and control groups. Inter-observer agreement for the presence or absence of the growth was excellent (κ coefficient, 0.82; 95% CI, 0.61-1.0). Multivariate logistic regression analysis showed that wider baseline bifurcation angles were significantly associated with subsequent progressions. The odds ratio for the progression of the second (145°-179°) or third (180°-274°) tertiles compared to the first tertile (46°-143°) were 5.5 (95% CI, 1.3-35). Besides, the bifurcation angle was positively correlated with the size of aneurysms (Spearman's rho, 0.39; P = 0.00014). The present study suggests the usefulness of the bifurcation angle for predicting the progression of sIAs

    Impact of hemodialysis on local vessel healing and thrombus formation after drug-eluting stent implantation

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    AbstractBackgroundAlthough hemodialysis (HD) is a suggested risk factor for stent thrombosis, its contribution to local vessel healing after drug-eluting stent (DES) implantation is unclear.MethodsA total of 121 patients (152 lesions treated with DES) who underwent 8-month follow-up coronary angiography with optical coherence tomography (OCT) were enrolled, and the findings were compared between patients with and without HD. To match baseline differences, mid-term OCT findings of 42 propensity score-matched lesions (21 non-HD vs. 21 HD) were compared. Effects of HD on the efficacy of antiplatelet therapy were also evaluated by VerifyNow assay (Accumetrics, San Diego, CA, USA).ResultsPatients with HD had a significantly higher rate of thrombus formation than those without (64% vs. 33%, p=0.007), although the baseline parameters and lesion characteristics differed between the groups. Multivariate logistic regression analysis revealed that HD was associated with an increased risk of thrombus formation (odds ratio 5.991, 95% confidence interval: 1.972–18.199, p=0.002). Even after propensity-matching for patient background and balancing of angiographic and OCT variables, the risk of thrombus formation remained significantly higher in HD patients. The P2Y12-reaction unit was significantly increased after HD (Pre HD: 211±75 vs. Post HD: 262±59, p=0.01), but patients without HD showed no increase during the same elapsed time (221±88 vs. 212±96, p=0.19).ConclusionsHD is a potential risk factor for subclinical thrombus attachment after DES therapy. Systemic problems, such as residual platelet reactivity, associated with HD as well as local vessel features in HD patients might contribute to the increased incidence of thrombus attachment and subsequent onset of thrombotic event after DES implantation

    Effect of Daily Glucose Fluctuation on Coronary Plaque Vulnerability in Patients Pre-Treated With Lipid-Lowering Therapy A Prospective Observational Study

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    AbstractObjectivesThis study sought to investigate the effect of daily glucose fluctuation on coronary plaque properties in patients with coronary artery disease (CAD) pre-treated with lipid-lowering therapy.BackgroundThere is growing evidence that glucose fluctuation, as a residual risk apart from dyslipidemia, is an important factor contributing to the development of CAD.MethodsThis prospective study enrolled 70 consecutive CAD patients who were referred for percutaneous coronary intervention and whose low-density lipoprotein cholesterol level was <120 mg/dl under statin treatment or <100 mg/dl without statins. Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE). The plaque properties in the culprit and nonculprit lesions were assessed by virtual histology intravascular ultrasound, and the volume percentage of necrotic core within the plaque (%NC) and the presence of thin-cap fibroatheroma were evaluated.ResultsIn total, 165 lesions were evaluated in 70 patients (40 diabetic and 30 nondiabetic patients). %NC was well correlated with MAGE (r = 0.490, p <0.001). A linear mixed effect model showed that MAGE had the strongest effect on %NC (coefficient β = 0.080 ± 0.020 [standard error], p < 0.001). The generalized linear mixed effect model revealed that MAGE was the only independent predictor of the presence of thin-cap fibroatheroma (odds ratio: 1.037; 95% confidence interval: 1.010 to 1.065; p = 0.007).ConclusionsDaily glucose fluctuation may have an effect on coronary plaque vulnerability in patients with CAD pre-treated with lipid-lowering therapy. Further investigations should address the rationale for the early detection and control of glucose fluctuation in the era of universal statin use for CAD patients

    Extraction and Geographical Navigation of Important Historical Events in the Web

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    We propose techniques for achieving the geographical navigation of historical events described in Web pages as “Virtual History Tour”. First, we develop a method for extracting information on the historical events from the Web and organizing it into a chronological table. Our method can effectively handle ambiguous cases – homonyms and multiple location names in a sentence – by using the number of co-occurrences among events, person names, location names, and addresses in the Web. Next, we propose a method for ranking historical entities according to their impacts at specific time and location. We extend the PageRank algorithm to calculate the temporal and spatial impacts of entities. Finally, we introduce our concrete application demonstrating how users can browse historical events through timeline and map interfaces

    Evaluating Significance of Historical Entities Based on Tempo-Spatial Impacts Analysis Using Wikipedia Link Structure

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    We propose a method to evaluate the signi cance of his- torical entities (people, events, and so on.). Here, the sig- ni cance of a historical entity means how it affected other historical entities. Our proposed method rst calculates the tempo-spacial impact of historical entities. The impact of a historical entity varies according to time and location. His- torical entities are collected from Wikipedia. We assume that a Wikipedia link between historical entities represents an impact propagation. That is, when an entity has a link to another entity, we regard the former is in uenced by the latter. Historical entities in Wikipedia usually have the date and location of their occurrence. Our proposed iteration al- gorithm propagates such initial tempo-spacial information through links in the similar manner as PageRank, so the tempo-spacial impact scores of all the historical entities can be calculated. We assume that a historical entity is signi - cant if it in uences many other entities that are far from it temporally or geographically. We demonstrate a prototype system and show the results of experiments that prove the effectiveness of our method
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