1,442 research outputs found
Research Centre for Healthy and Sustainable Living
[EN] The Research Centre for Healthy and Sustainable Living of the University of Applied Sciences Utrecht aims to enable healthy urban living. According to the latest concept, health entails the capacity to respond resiliently to stressors that disturb homeostasis. In addition, an individual’s health benefits from the ability to self-manage and is determined by personalized conditions. One of the derived research challenges is to obtain know-how (biomarkers) and tools (e.g. point-of-care, wearables) to monitor an individual’s health condition in daily life. The well-known quotes “you are what you eat” and “sitting is the new smoking” indicate that condition of the oro-gastrointestinal tract and physical activity are pivotal to health. With this popular knowledge, we set out to identify biomarkers to monitor health benefits from nutrition and physical activity. Our first studies with human volunteers indicated that immune and intestinal parameters are responsive to physical stress (performed on a bicycle ergometer) in a clear kinetic manner, related to extent of physical activity and influenced by an unhealthy condition (deprivation of water intake during exercise). Our next research goals are to: -evaluate the initial selection of biomarkers in specific patient-groups and; -how these biomarkers are influenced by the condition of the oro-gastrointestinal tract, e.g. via nutrition.Pieters, R.; Bleijenberg, N.; Jerkovic, K.; Krul, C.; Veenhof, C.; Wittink, H. (2020). Research Centre for Healthy and Sustainable Living. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/156433OC
Supplementary material for the article: Perusko, M.; van Roest, M.; Stanic-Vucinic, D.; Simons, P. J.; Pieters, R. H. H.; Cirkovic Velickovic, T.; Smit, J. J. Glycation of the Major Milk Allergen β-Lactoglobulin Changes Its Allergenicity by Alterations in Cellular Uptake and Degradation. Molecular Nutrition and Food Research 2018, 62 (17). https://doi.org/10.1002/mnfr.201800341
Supplementary material for: [https://doi.org/10.1002/mnfr.201800341]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2212
CTLA-4 Signaling Regulates the Intensity of Hypersensitivity Responses to Food Antigens, but is Not Decisive in the Induction of Sensitization
Although food allergy has emerged as a major health problem, the mechanisms that are decisive in the development of sensitization to dietary Ag remain largely unknown. CTLA-4 signaling negatively regulates immune activation, and may play a crucial role in preventing induction and/or progression of sensitization to food Ag. To elucidate the role of CTLA-4 signaling in responses to food allergens, a murine model of peanut allergy was used. During oral exposure to peanut protein extract (PPE) together with the mucosal adjuvant cholera toxin (CT), which induces peanut allergy, CTLA-4 ligation was prevented using a CTLA-4 mAb. Additionally, the effect of inhibition of the CTLA-4 pathway on oral exposure to PPE in the absence of CT, which leads to unresponsiveness to peanut Ag, was explored. During sensitization, anti-CTLA-4 treatment considerably enhanced IgE responses to PPE and the peanut allergens, Ara h 1, Ara h 3, and Ara h 6, resulting in elevated mast cell degranulation upon an oral challenge. Remarkably, antagonizing CTLA-4 during exposure to PPE in the absence of CT resulted in significant induction of Th2 cytokines and an elevation in total serum IgE levels, but failed to induce allergen-specific IgE responses and mast cell degranulation upon a PPE challenge. These results indicate that CTLA-4 signaling is not the crucial factor in preventing sensitization to food allergens, but plays a pivotal role in regulating the intensity of a food allergic sensitization response. Furthermore, these data indicate that a profoundly Th2-biased cytokine environment is insufficient to induce allergic responses against dietary Ag
Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission
We study the spectrophotometric properties of dwarf planet Ceres in the
VIS-IR spectral range by means of hyper-spectral images acquired by the VIR
imaging spectrometer on board the NASA Dawn mission. Disk-resolved observations
with a phase angle within the interval were used
to characterize Ceres' phase curve in the 0.465-4.05 m spectral range.
Hapke's model was applied to perform the photometric correction of the dataset,
allowing us to produce albedo and color maps of the surface. The -band
magnitude phase function of Ceres was fitted with both the classical linear
model and H-G formalism. The single-scattering albedo and the asymmetry
parameter at 0.55m are and ,
respectively (two-lobe Henyey-Greenstein phase function); the modeled geometric
albedo is ; the roughness parameter is
. Albedo maps indicate small variability
on a global scale with an average reflectance of . Isolated
areas such as the Occator bright spots, Haulani, and Oxo show an albedo much
higher than average. We measure a significant spectral phase reddening, and the
average spectral slope of Ceres' surface after photometric correction is
and at VIS and IR wavelengths, respectively.
Broadband color indices are and . H-G
modeling of the -band magnitude phase curve for gives
and , while the classical linear model provides
and . The comparison with
spectrophotometric properties of other minor bodies indicates that Ceres has a
less back-scattering phase function and a slightly higher albedo than comets
and C-type objects. However, the latter represents the closest match in the
usual asteroid taxonomy.Comment: 14 pages, 20 figures, published online on Astronomy and Astrophysics
on 13 February 2017. Revised to reflect minor changes in text and figures
made in proofs, updated value of V-R and R-
The kiwifruit allergen act d 1 activates NF-κB signaling and affects mRNA expression of TJ proteins and innate pro-allergenic cytokines
Impairment of the intestinal barrier is one of the key events in the initiation of the sensitization process in food allergy. The aim of this study was to explore the effects of kiwifruit allergen Act d 1 on intestinal permeability and tight junction protein (TJP) gene expression in vivo and to explore its potential to activate the NF-ĸB signaling pathway and to regulate expression of epithelial pro-allergenic cytokines. Influences of Act d 1 on TJP gene expression and pro-allergenic cytokines in the mouse intestine was analyzed by qPCR upon allergen administration by oral gavage. The effect on the in vivo intestinal permeability was assessed in ELISA by measuring the translocation of β-lactoglobulin (BLG) into circulation. The capacity of Act d 1 to activate the NF-ĸB pathway was tested in HEK293 cells by fluorescent microscopy and flow cytometry. Administration of Actinidin (Act d 1) increased intestinal permeability to the BLG. This was accompanied by changes in gene expression of TJP mRNA and pro-allergenic cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) compared to the control. Act d 1 reduced TEER of the HEK293 monolayer, was positive in an NF-ĸB-reporter HEK293 cell assay, and induced secretion of TSLP. These findings shed more light on the molecular events in the sensitization process of kiwifruit but possibly also of other protease food allergens
Ultraviolet Spectroscopy of Asteroid (4) Vesta
We report a comprehensive review of the UV-visible spectrum and rotational
lightcurve of Vesta combining new observations by Hubble Space Telescope and
Swift Gamma-ray Burst Observatory with archival International Ultraviolet
Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm are
derived by carefully comparing these observations from various instruments at
different times and observing geometries. Vesta has a rotationally averaged
geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673
nm, and 0.30 at 950 nm. The linear spectral slope as measured between 240 and
320 nm in the ultraviolet displays a sharp minimum near a sub-Earth longitude
of 20^{\circ}, and maximum in the eastern hemisphere. This is consistent with
the longitudinal distribution of the spectral slope in the visible wavelength.
The photometric uncertainty in the ultraviolet is ~20%, and in the visible
wavelengths it is better than 10%. The amplitude of Vesta's rotational
lightcurves is ~10% throughout the range of wavelengths we observed, but is
smaller at 950 nm (~6%) near the 1-\mum band center. Contrary to earlier
reports, we found no evidence for any difference between the phasing of the
ultraviolet and visible/near-infrared lightcurves with respect to sub-Earth
longitude. Vesta's average spectrum between 220 and 950 nm can well be
described by measured reflectance spectra of fine particle howardite-like
materials of basaltic achondrite meteorites. Combining this with the in-phase
behavior of the ultraviolet, visible, and near-infrared lightcurves, and the
spectral slopes with respect to the rotational phase, we conclude that there is
no global ultraviolet/visible reversal on Vesta. Consequently, this implies a
lack of global space weathering on Vesta, as previously inferred from
visible-near-infrared data.Comment: 44 pages, 5 figures, 1 tabl
Comparison of Six Commercial ELISA Kits for Their Specificity and Sensitivity in Detecting Different Major Peanut Allergens
Six commercial peanut enzyme-linked immunosorbent assay kits were assessed for their ability to recover peanut from the standard reference material 2387 peanut butter and also for their specificity in detecting four major peanut allergens, Ara h 1, Ara h 2, Ara h 3, and Ara h 6. The percentage recovery of peanut from peanut butter differed across different kits as well as at different sample concentrations. The highest recovery was observed with the Romer and R-Biopharm kits, while four other kits were found to underestimate the protein content of the reference peanut butter samples. Five of the kits were most sensitive in detecting Ara h 3 followed by Ara h 1, while hardly recognizing Ara h 2 and Ara h 6. The other kit showed the highest sensitivity to Ara h 2 and Ara h 6, while Ara h 1 and Ara h 3 were poorly recognized. Although Ara h 2 and Ara h 6 are known to be heat stable and more potent allergens, antisera specific to any of these four peanut proteins/allergens may serve as good markers for the detection of peanut residues
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