400 research outputs found

    Assessment of drug-eluting stents and bioresorbable stents by grayscale IVUS and IVUS-based imaging modalities

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    Grayscale IVUS and IVUS-based imaging modalities during the last years have become useful in the assessment not only of drug eluting stent, but also of new bioresorbable vascular scaffolds. Although IVUS resolution is not sufficient for determining stent coverage (optical coherence tomography is the gold standard), serial IVUS can measure intimal hyperplasia, assess acute and late incomplete stent apposition, detect the presence and persistence of edge dissections, study edge effects and look for causes of restenosis and thrombosis. In addition other IVUS-based imaging modalities, such as IVUS-VH, iMAP or palpography, can be used to study the serial compositional and mechanical changes of the plaque behind stent struts and also to follow the bioresorption of the new bioresorbable scaffolds, analyzing the backscattering signal coming from the polymeric struts. This revi

    Frequency and predictors of thrombus inside the guiding catheter during interventional procedures: an optical coherence tomography study

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    Optical coherence tomography (OCT) is able to identify thrombus. We detect the frequency of thrombus inside the guiding catheter by OCT and its relationship with clinical and procedural factors. We screened 77 patients who underwent OCT pullbacks. Only patients with visible guiding catheter were finally included (35) and divided into thrombus (21) or no-thrombus group (14). Patients within thrombus group were mostly males (100 vs. 71 %, p = 0.05), with acute coronary syndrome (76 vs. 36 %, p = 0.02) and received more frequently percutaneous coronary intervention (86 vs. 43 %, p = 0.01) as compared to other group. A second dose of heparin was more frequently administered in thrombus than in other group (86 vs. 50 %, p = 0.01). Time between first heparin administration and OCT pullback (41[28–57] vs. 20 min [10–32], p = 0.001), time elapsed from second heparin administration and OCT pullback (29 [19–48] vs. 16 min [12–22], p = 0.002) and total procedural time (47 [36–69] vs. 31 min [26–39], p = 0.005) were longer in thrombus compared to other group. At multivariate analysis, total procedural time and time between first heparin administration and OCT pullback were only predictors of intra-catheter thrombus (HR 0.6 [0.3–0.9], p = 0.03 and HR 1.9 [1.1–3.2], p = 0.02, respectively). Thrombus inside guiding catheter may be a frequent finding in long interventional procedure. Future studies are warranted to determine its clinical impact

    Evolution of Human Memory B Cells From Childhood to Old Age

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    High quality medical assistance and preventive strategies, including pursuing a healthy lifestyle, result in a progressively growing percentage of older people. The population and workforce is aging in all countries of the world. It is widely recognized that older individuals show an increased susceptibility to infections and a reduced response to vaccination suggesting that the aged immune system is less able to react and consequently protect the organism. The SARS-CoV-2 pandemic is dramatically showing us that the organism reacts to novel pathogens in an age-dependent manner. The decline of the immune system observed in aging remains unclear. We aimed to understand the role of B cells. We analyzed peripheral blood from children (4-18 years); young people (23-60 years) and elderly people (65-91 years) by flow cytometry. We also measured antibody secretion by ELISA following a T-independent stimulation. Here we show that the elderly have a significant reduction of CD27dull memory B cells, a population that bridges innate and adaptive immune functions. In older people, memory B cells are mostly high specialized antigen-selected CD27bright. Moreover, after in vitro stimulation with CpG, B cells from older individuals produced significantly fewer IgM and IgA antibodies compared to younger individuals. Aging is a complex process characterized by a functional decline in multiple physiological systems. The immune system of older people is well equipped to react to often encountered antigens but has a low ability to respond to new pathogens
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