Allergy to Edible Insects: A Computational Identification of the IgE-Binding Cross-Reacting Allergen Repertoire of Edible Insects

Allergic manifestations to the ingestion of edible insects have been reported, especially in countries where edible insects are traditionally consumed. However, to date, allergens of edible insects have been poorly investigated. The AllergenOnline server was used for assessing the allergenic character of the putative IgE-binding cross-reactive allergens from the consumed yellow mealworm, silkworm, house fly maggot, migratory locust, house cricket, greater wax moth, black soldier fly, American grasshopper and Indian mealmoth. Positive hits correspond to allergens exhibiting >35% identity over an 80-residue sliding window and 100% identity over an 8-residue sliding window, respectively. Most of the hits consist of allergens from arthropods such as dust mites, crustaceans and insects, and more rarely, of allergens from mollusks, nematodes, and fungi. All the identifed allergens share conserved amino acid sequences and three-dimensional structures. Accordingly, the allergens of edible insects form clusters closely related to crustacean, mollusk and nematode clusters into the phylogenetic trees built up from the sequence alignments. Our computational investigations suggest edible insects possess a large repertoire of IgE-binding allergens they share with phylogenetically related groups of arthropods, mollusks, and nematodes. These cross-reacting allergens are susceptible to trigger allergic reactions in individuals previously sensitized to shellfish or mollusks

The fine sugar specificity of the Lathyrus ochrus seed lectin and isolectins

AbstractGlycoproteins and their derived glycopeptides have been used to define the specificity of the Lathyrus ochrus lectin and isolectins, by determining their ability to inhibit the agglutination of human erythrocytes induced by the lectin or isolectins. This α-D-mannose/α-D-glucose-specific lectin possessess the ability to recognize a well-defined saccharide sequence on a bi-antennary N-acetyllactosamine-type glycan. For other Vicieae lectins, the best inhibitor is a glycopeptide from human lactotransferrin with an α-L-fucose residue at the C-6 position on the N-acetylglucosamine residue involved in the N-glycosylamine bond. This fucose seems to be a major determinant of the binding since its removal with an α-L-fucosidase gives glycopeptides 8-fold less inhibitory. Our results confirm that the Vicieae lectins are evolutionarily related proteins even at the level of their binding sites

Cascaded multitask U-Net using topological loss for vessel segmentation and centerline extraction

Vessel segmentation and centerline extraction are two crucial preliminary tasks for many computer-aided diagnosis tools dealing with vascular diseases. Recently, deep-learning based methods have been widely applied to these tasks. However, classic deep-learning approaches struggle to capture the complex geometry and specific topology of vascular networks, which is of the utmost importance in most applications. To overcome these limitations, the clDice loss, a topological loss that focuses on the vessel centerlines, has been recently proposed. This loss requires computing, with a proposed soft-skeleton algorithm, the skeletons of both the ground truth and the predicted segmentation. However, the soft-skeleton algorithm provides suboptimal results on 3D images, which makes the clDice hardly suitable on 3D images. In this paper, we propose to replace the soft-skeleton algorithm by a U-Net which computes the vascular skeleton directly from the segmentation. We show that our method provides more accurate skeletons than the soft-skeleton algorithm. We then build upon this network a cascaded U-Net trained with the clDice loss to embed topological constraints during the segmentation. The resulting model is able to predict both the vessel segmentation and centerlines with a more accurate topology.Comment: 13 pages, 4 figure

Legume lectins interact with muramic acid and N-acetylmuramic acid

AbstractThe inhibitory potency of both muramic acid (MurAc) and N-acetylmuramic acid (MurNAc) on various legume lectins, including Glc/Man- and Gal/GalNAc-specific lectins, was investigated by a haemagglutination inhibition technique. Data indicated that many lectins, especially those specific for Glc/Man, specifically interact with MurAc and MurNAc often to a greater extent than with other monosaccharides and their derivatives, such as N-acetylglucosamine (GlcNAc) and sialic acid. Glc/Man-specific lectins were also shown to interact with the muramyl-dipeptide MurNAc-D-Ala-D-isoGln. These interactions could explain why various lectins readily agglutinate some bacterial strains or which cell walls contain peptidoglycans with high amounts of MurNAc

Modeling and hexahedral meshing of cerebral arterial networks from centerlines

Computational fluid dynamics (CFD) simulation provides valuable information on blood flow from the vascular geometry. However, it requires extracting precise models of arteries from low-resolution medical images, which remains challenging. Centerline-based representation is widely used to model large vascular networks with small vessels, as it encodes both the geometric and topological information and facilitates manual editing. In this work, we propose an automatic method to generate a structured hexahedral mesh suitable for CFD directly from centerlines. We addressed both the modeling and meshing tasks. We proposed a vessel model based on penalized splines to overcome the limitations inherent to the centerline representation, such as noise and sparsity. The bifurcations are reconstructed using a parametric model based on the anatomy that we extended to planar n-furcations. Finally, we developed a method to produce a volume mesh with structured, hexahedral, and flow-oriented cells from the proposed vascular network model. The proposed method offers better robustness to the common defects of centerlines and increases the mesh quality compared to state-of-the-art methods. As it relies on centerlines alone, it can be applied to edit the vascular model effortlessly to study the impact of vascular geometry and topology on hemodynamics. We demonstrate the efficiency of our method by entirely meshing a dataset of 60 cerebral vascular networks. 92% of the vessels and 83% of the bifurcations were meshed without defects needing manual intervention, despite the challenging aspect of the input data. The source code is released publicly

Ca(OH)2/CaO reversible reaction in a fluidized bed reactor for thermochemical heat storage

Thermal energy storage (TES) is a key factor for increasing the efficiency of concentrated solar power plants. TES using a reversible chemical reaction appears to be a promising technology for high energy density thermal storage (100–500 kW h m-3), at high temperature(up to 1000 °C) and during a long period (24 h to several months). This paper details an experimental study to carry out the reversible reaction Ca(OH)2(s) + DHr CaO(s) + H2O(g) in a fluidized bed (FB) reactor. The 4 micron Ca(OH)2 powder fluidization has been performed with an appropriate proportion of inert easy-to-fluidize particles. Then, Ca(OH)2 dehydration and CaO hydration have been implemented in a FB reactor and 50 cycles have been reached. The mean energy density obtained is 60 kW h m-3 solid_mixture which amounts to a promising energy density of 156 kW h m-3 Ca(OH)2-bulk if the reactants and the easy-to-fluidize particles are separated. The results demonstrated the feasibility of the implementation of the Ca(OH)2/CaO thermochemical heat storage in a fluidized bed reactor

Man-specific, GalNAc/T/Tn-specific and Neu5Ac-specific seaweed lectins as glycan probes for the SARS-CoV-2 (COVID-19) coronavirus

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells—in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed

A review on high temperature thermochemical heat energy storage

Solar thermal energy represents an increasingly attractive renewable source.However,to provide continuous availability of this energy,it must be stored. This paper presents the state of the art on high temperature(573-1273K)solar thermal energy storage based on chemical reactions,which seems to be the most advantageous one for long-term storage. The paper summarizes the numerical,experimental and technological studies done so far. Each system is described and the advantages and drawbacks of each reaction couple are considered

Differences in the mannose oligomer specificities of the closely related lectins from Galanthus nivalis and Zea mays strongly determine their eventual anti-HIV activity

<p>Abstract</p> <p>Background</p> <p>In a recent report, the carbohydrate-binding specificities of the plant lectins <it>Galanthus nivalis </it>(GNA) and the closely related lectin from <it>Zea mays </it>(GNA_maize) were determined by glycan array analysis and indicated that GNA_maizerecognizes complex-type N-glycans whereas GNA has specificity towards high-mannose-type glycans. Both lectins are tetrameric proteins sharing 64% sequence similarity.</p> <p>Results</p> <p>GNA_maizeappeared to be ~20- to 100-fold less inhibitory than GNA against HIV infection, syncytia formation between persistently HIV-1-infected HuT-78 cells and uninfected CD4⁺T-lymphocyte SupT1 cells, HIV-1 capture by DC-SIGN and subsequent transmission of DC-SIGN-captured virions to uninfected CD4⁺T-lymphocyte cells. In contrast to GNA, which preferentially selects for virus strains with deleted high-mannose-type glycans on gp120, prolonged exposure of HIV-1 to dose-escalating concentrations of GNA_maizeselected for mutant virus strains in which one complex-type glycan of gp120 was deleted. Surface Plasmon Resonance (SPR) analysis revealed that GNA and GNA_maizeinteract with HIV III_Bgp120 with affinity constants (K_D) of 0.33 nM and 34 nM, respectively. Whereas immobilized GNA specifically binds mannose oligomers, GNA_maizeselectively binds complex-type GlcNAcβ1,2Man oligomers. Also, epitope mapping experiments revealed that GNA and the mannose-specific mAb 2G12 can independently bind from GNA_maizeto gp120, whereas GNA_maizecannot efficiently bind to gp120 that contained prebound PHA-E (GlcNAcβ1,2man specific) or SNA (NeuAcα2,6X specific).</p> <p>Conclusion</p> <p>The markedly reduced anti-HIV activity of GNA_maizecompared to GNA can be explained by the profound shift in glycan recognition and the disappearance of carbohydrate-binding sites in GNA_maizethat have high affinity for mannose oligomers. These findings underscore the need for mannose oligomer recognition of therapeutics to be endowed with anti-HIV activity and that mannose, but not complex-type glycan binding of chemotherapeutics to gp120, may result in a pronounced neutralizing activity against the virus.</p