31 research outputs found

    Mast cells disrupt the function of the esophageal epithelial barrier

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    Mast cells (MCs) accumulate in the epithelium of patients with eosinophilic esophagitis (EoE), an inflammatory disorder characterized by extensive esophageal eosinophilic infiltration. Esophageal barrier dysfunction plays an important role in the pathophysiology of EoE. We hypothesized that MCs contribute to the observed impaired esophageal epithelial barrier. Herein, we demonstrate that coculture of differentiated esophageal epithelial cells with immunoglobulin E-activated MCs significanly decreased epithelial resistance by 30% and increased permeability by 22% compared with non-activated MCs. These changes were associated with decreased messenger RNA expression of barrier proteins filaggrin, desmoglein-1 and involucrin, and antiprotease serine peptidase inhibitor kazal type 7. Using targeted proteomics, we detected various cytokines in coculture supernatants, most notably granulocyte-macrophage colony-stimulating factor and oncostatin M (OSM). OSM expression was increased by 12-fold in active EoE and associated with MC marker genes. Furthermore, OSM receptor-expressing esophageal epithelial cells were found in the esophageal tissue of patients with EoE, suggesting that the epithelial cells may respond to OSM. Stimulation of esophageal epithelial cells with OSM resulted in a dose-dependent decrease in barrier function and expression of filaggrin and desmoglein-1 and an increase in protease calpain-14. Taken together, these data suggest a role for MCs in decreasing esophageal epithelial barrier function in EoE, which may in part be mediated by OSM

    Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers

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    An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescensBenth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule morphology. The obtained formulations were slightly yellow, odorless, and had a pleasant taste. The average diameters of the microcapsules were 0.4679 ”m (F2-MC), 0.5885 ”m (F3-MC), and 0.9033 ”m (F1-MC). The best formulation was F3-MC, with FHPp microencapsulation efficiency of 61.01 ± 2.00% and an in vitro release profile of 75.88 ± 0.45%; the content of vouacapans 3-4 was 99.49 ± 2.80%. The best model to describe the release kinetics for F1-MC and F3-MC was that proposed by Higuchi; however, F2-MC release displayed first-order kinetics; the release mechanism was of the supercase II type for all formulations

    A comparison of two Bayesian approaches for uncertainty quantification

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    Statistical calibration of model parameters conditioned on observations is performed in a Bayesian framework by evaluating the joint posterior probability density function (pdf) of the parameters. The posterior pdf is very often inferred by sampling the parameters with Markov Chain Monte Carlo (MCMC) algorithms. Recently, an alternative technique to calculate the so-called Maximal Conditional Posterior Distribution (MCPD) appeared. This technique infers the individual probability distribution of a given parameter under the condition that the other parameters of the model are optimal. Whereas the MCMC approach samples probable draws of the parameters, the MCPD samples the most probable draws when one of the parameters is set at various prescribed values. In this study, the results of a user-friendly MCMC sampler called DREAM((zs)) and those of the MCPD sampler are compared. The differences between the two approaches are highlighted before running a comparison inferring two analytical distributions with collinearity and multimodality. Then, the performances of both samplers are compared on an artificial multistep outflow experiment from which the soil hydraulic parameters are inferred. The results show that parameter and predictive uncertainties can be accurately assessed with both the MCMC and MCPD approaches

    Structure and mechanical properties of swift heavy ion irradiated tungsten-bearing delta-phase oxides Y6W1O12 and Yb6W1O12

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    We report on the relationship between structure and mechanical properties of complex oxides whose structures are derivatives of fluorite, following irradiation with swift heavy ion (92 MeV Xe) which approximately simulates fission product irradiation, where the electronic energy loss dominates. The two compounds of interest in this paper are Y6W1O12 and Yb6W1O12. These compounds possess an ordered, fluorite derivative crystal structure known as the delta (delta) phase, a rhombohedral structure belonging to space group R (3) over bar
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