254 research outputs found

    Val247Leu beta2-glycoprotein-I allelic variant is associated with antiphospholipid syndrome: Systematic review and meta-analysis

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    [EN] Previous studies have suggested that the possession of the Val/Val genotype of the Val247Leu polymorphism of the β2-glycoproteinI (β2-GPI) gene may be associated with antiphospholipid syndrome (APS), and, among patients with APS, with the production of anti-β2-GPI antibodies or the development of thrombosis. Given the controversial results reported, the aim of this work is to combine previous findings by means of a systematic review and a meta-analysis. Methods: We retrieved studies analyzing the genotype of the above-mentioned polymorphism among patients with APS by means of electronic database search. A meta-analysis was conducted in a random effects model and calculations of odds ratio (OR) and confidence intervals (CI) were done. Sensitivity analysis and tests for heterogeneity of the results were performed. Results: Eight previous studies analyzed the association of APS, anti-β2-GPI antibodies and/or thrombosis with the Val247Leu polymorphism. After meta-analysis, patients with APS had a significantly higher prevalence of the Val/ Val genotype of this genetic variant when compared with controls (OR=2.04; 95% CI: 1.12, 3.73; P=0.02). Among patients with APS, those with anti-β2-GPI antibodies had a higher prevalence of this genotype (OR=1.73; 95% CI: 1.04, 2.87; P=0.03). No significant results were found for the presence of arterial or venous thrombosis. Conclusions: Val/Val genotype of β2-GPI gene is associated with a significant excess risk to suffer from APS and, among patients with APS, to have anti-β2-GPI antibodies. No definite conclusions can be made regarding the association of this polymorphism with thrombosis among APS patients. © 2

    Anisotropic Diffusion Filter with Memory based on Speckle Statistics for Ultrasound Images

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    Ultrasound imaging exhibits considerable difficulties for medical visual inspection and for the development of automatic analysis methods due to speckle, which negatively affects the perception of tissue boundaries and the performance of automatic segmentation methods. With the aim of alleviating the effect of speckle, many filtering techniques are usually considered as a preprocessing step prior to automatic analysis methods or visual inspection. Most of the state-of-the-art filters try to reduce the speckle effect without considering its relevance for the characterization of tissue nature. However, the speckle phenomenon is the inherent response of echo signals in tissues and can provide important features for clinical purposes. This loss of information is even magnified due to the iterative process of some speckle filters, e.g., diffusion filters, which tend to produce over-filtering because of the progressive loss of relevant information for diagnostic purposes during the diffusion process. In this work, we propose an anisotropic diffusion filter with a probabilistic-driven memory mechanism to overcome the over-filtering problem by following a tissue selective philosophy. Specifically, we formulate the memory mechanism as a delay differential equation for the diffusion tensor whose behavior depends on the statistics of the tissues, by accelerating the diffusion process in meaningless regions and including the memory effect in regions where relevant details should be preserved. Results both in synthetic and real US images support the inclusion of the probabilistic memory mechanism for maintaining clinical relevant structures, which are removed by the state-of-the-art filters

    Multi-Oriented Windowed Harmonic Phase Reconstruction for Robust Cardiac Strain Imaging

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    The purpose of this work is to develop a method for direct estimation of the cardiac strain tensor by extending the harmonic phase reconstruction on tagged magnetic resonance images to obtain more precise and robust measurements. The extension relies on the reconstruction of the local phase of the image by means of the windowed Fourier transform and the acquisition of an overdetermined set of stripe orientations in order to avoid the phase interferences from structures outside the myocardium and the instabilities arising from the application of a gradient operator. Results have shown that increasing the number of acquired orientations provides a signi cant improvement in the reproducibility of the strain measurements and that the acquisition of an extended set of orientations also improves the reproducibility when compared with acquiring repeated samples from a smaller set of orientations. Additionally, biases in local phase estimation when using the original harmonic phase formulation are greatly diminished by the one here proposed. The ideas here presented allow the design of new methods for motion sensitive magnetic resonance imaging, which could simultaneously improve the resolution, robustness and accuracy of motion estimates

    Non-Rigid Groupwise Registration for Motion Estimation and Compensation in Compressed Sensing Reconstruc- tion of Breath-Hold Cardiac Cine MRI

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    Purpose: Compressed sensing methods with motion estimation and compensation techniques have been proposed for the reconstruction of accelerated dynamic MRI. However, artifacts that naturally arise in compressed sensing reconstruction procedures hinder the estimation of motion from reconstructed images, especially at high acceleration factors. This work introduces a robust groupwise non-rigid motion estimation technique applied to the compressed sensing reconstruction of dynamic cardiac cine MRI sequences. Theory and Methods: A spatio-temporal regularized, groupwise, non-rigid registration method based on a B-splines deformation model and a least squares metric is used to estimate and to compensate the movement of the heart in breath-hold cine acquisitions and to obtain a quasi-static sequence with highly sparse representation in temporally transformed domains. Results: Short axis in vivo datasets are used for validation, both original multi-coil as well as DICOM data. Fully sampled data were retrospectively undersampled with various acceleration factors and reconstructions were compared with the two well-known methods k-t FOCUSS and MASTeR. The proposed method achieves higher signal to error ratio and structure similarity index for medium to high acceleration factors. Conclusions: Reconstruction methods based on groupwise registration show higher quality recon- structions for cardiac cine images than the pairwise counterparts tested

    The Effect of Lifestyle Intervention on Health-Related Quality of Life in Adults with Metabolic Syndrome: A Meta-Analysis

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    [EN] The aim of this meta-analysis was to assess the effects of a lifestyle intervention through health education on nutrition, physical activity, and healthy habits on physical and mental health-related quality of life (HRQoL), in adults with metabolic syndrome (MetS). The databases used were PubMed, WOS, and Scopus. The inclusion criteria were: observational, longitudinal and randomized clinical trial (RCT) study designs, adults (both sexes), with at least two criteria of MetS, lifestyle intervention and comparison with a control group, and a measurement of HRQoL with a validated questionnaire. We analyzed the Hedges’ g and SF-36 score. I2 statistics were calculated and possible publication and small study biases were assessed using Egger’s test and funnel plots. Seven RCTs were selected for meta-analysis, based on 637 study participants. Significant improvements were found in the physical dimensions of the HRQoL scores for subjects in the active intervention compared to the group that received general lifestyle information (Hedges’ g 0.61, 95% confidence interval (CI) = 0.31–0.91). Mental health-related quality of life was also significantly improved in the intervention group compared with the control group (Hedges’ g 0.84, 95% CI = 0.64–1.03). In conclusion, our results suggest that, according to the RCTs selected for this meta-analysis, a lifestyle intervention significantly improves HRQoL in all its domains.SIThis research was funded by Fondo de Investigación para la Salud (FIS), which is co-funded by the European Regional Development Fund grant PI17/00532

    Native Trichoderma Isolates from Soil and Rootstock to Fusarium spp. Control and Growth Promotion of Humulus lupulus L. Plantlets

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    [EN] Fusarium genus is a wide host phytopathogen causing significant losses in multiple crops, including hops. There is limited information on the sustainable management of Fusarium spp. in hop fields. Trichoderma is an endophytic fungus used in agriculture as a biological control agent (BCA) and as a plant growth promoter. It has been used to antagonize Fusarium spp. in other crops. The objective of the current study was to identify indigenous hop field Trichoderma isolates with biocontrol and hop growth promotion capabilities. Three isolates of Fusarium and eleven autochthonous Trichoderma isolates collected from sustainable hop fields were evaluated in this work. Direct confrontation tests (the physical interaction between the pathogen and BCA and their competition for space and nutrient resources) and membrane tests (the capacity of the BCA to produce metabolites or enzymes through a cellophane film and inhibit the development of the pathogen) assessed the antagonism of these Trichoderma isolates against Fusarium culmorum, F. sambucinum, and F. oxysporum. A bioassay with hop plantlets inoculated with a spore suspension of Trichoderma was performed to assess its hop growth enhancement. T. hamatum (T311 and T324), T. virens T312, and T. gamsii T327 showed high growth inhibition of Fusarium spp. phytopathogens and high plant growth promotion. Native Trichoderma isolates from sustainable hop-producing soils have great potential as BCAs and hop growth promotersSIThis research was funded by the Ministerio de Universidades (Spain), grant number FPU19/03650 to A.J.P.-Á., and the Ministerio de Agricultura, Pesca y Alimentación (Spain), Quality Hops Operational Group, Innovations in the cultivation of hops in Spain to improve the sustainability of farms (2019/00179/001

    Multi-Stencil Streamline Fast Marching: a general 3D Framework to determine Myocardial Thickness and Transmurality in Late Enhancement Images

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    We propose a fully three-dimensional methodology for the computation of myocardial non-viable tissue transmurality in contrast enhanced magnetic resonance images. The outcome is a continuous map defined within the myocardium where not only current state-of-the-art measures of transmurality can be calculated, but also information on the location of non-viable tissue is preserved. The computation is done by means of a partial differential equation framework we have called Multi- Stencil Streamline Fast Marching (MSSFM). Using it, the myocardial and scarred tissue thickness is simultaneously computed. Experimental results show that the proposed 3D method allows for the computation of transmurality in myocardial regions where current 2D methods are not able to as conceived, and it also provides more robust and accurate results in situations where the assumptions on which current 2D methods are based —i.e., there is a visible endocardial contour and its corresponding epicardial points lie on the same slice—, are not met

    The TRPM8 antagonist RGM8-51 displays analgesic activity in different pain models

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    TRPM8 channels are overexpressed in sensory neurons after nerve injury or inflammation, resulting in enhanced sensitivity (allodynia and hyperalgesia) to physical stimulation, and have been implicated in migraine, but the interest of TRPM8 antagonists is still a matter of controversy (1,2). The aim of our work was to evaluate the analgesic activity of a TRPM8 antagonist, RGM8-51, in different pain models, looking for similarities and differences with other antagonists. To this end, we used the mouse oxaliplatin-induced peripheral neuropathy, the chronic constriction injury of the rat sciatic nerve (CCI) and mouse NTG-induced migraine-like models. Compound RGM8- 51 reduces the cold allodynia induced by oxaliplatin, from 15 to 60 min after administration (0.1-1 μg, i.pl.), decreases the nocifensive responses to cold, heat and mechanical stimuli in the CCI model (10 μg, i.pl., 30 mg/Kg, i.p.), and relief chronic pain associated to migraine in mouse, in a sex-dependent manner (10 or 30 mg/Kg, i.v.). The β–lactam derivative RGM8-51 not only has analgesic activity in all assayed animal models, but also seems to have a different mode of interaction with the TRPM8 channel than other antagonists, as suggested by docking studies

    Fast 4D elastic group-wise image registration. Convolutional interpolation revisited

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    Background and Objective:This paper proposes a new and highly efficient implementation of 3D+t groupwise registration based on the free-form deformation paradigm. Methods:Deformation is posed as a cascade of 1D convolutions, achieving great reduction in execution time for evaluation of transformations and gradients. Results:The proposed method has been applied to 4D cardiac MRI and 4D thoracic CT monomodal datasets. Results show an average runtime reduction above 90%, both in CPU and GPU executions, compared with the classical tensor product formulation. Conclusions:Our implementation, although fully developed for the metric sum of squared differences, can be extended to other metrics and its adaptation to multiresolution strategies is straightforward. Therefore, it can be extremely useful to speed up image registration procedures in different applications where high dimensional data are involved.MEC-TEC2017-82408-
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