19 research outputs found

    Hot-Lithography SLA-3D Printing of Epoxy Resin

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    The hot-lithography stereolithography 3D printing technology is used to print epoxy resins with high reactivity in order to achieve 3D printed structures. Different hydroxyl containing compounds are investigated as chain transfer agents and the viscoelastic properties of UV-cured materials are fully characterized. The most promising formulations are studied at a high temperature, the 3D printing process parameters are defined and the printed object is fully characterized. By combining the suitable precursor materials in the photocurable formulation with the advanced hot-lithography process, it is possible to produce 3D printed structures that are characterized by outstanding thermomechanical properties and good printability precision

    Visualization of clustered IgE epitopes on α-lactalbumin

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    Background: α-Lactalbumin (α-La) is a major cow's milk (CM) allergen responsible for allergic reactions in infants. Objective: We performed molecular, structural, and immunologic characterization of α-La. Methods: Recombinant α-lactalbumin (rα-La) was expressed in Escherichia coli, purified to homogeneity, and characterized by means of mass spectrometry and circular dichroism, and its allergenic activity was studied by using microarray technology, as well as in a basophil histamine release assay. IgE epitope mapping was performed with synthetic peptides. Results: According to circular dichroism analysis, rα-La represented a folded protein with a high thermal stability and refolding capacity. rα-La reacted with IgE antibodies from 57.6% of patients with CM allergy (n = 66) and induced the strongest basophil degranulation with sera from patients with CM allergy who had exhibited gastrointestinal symptoms or severe systemic reactions on CM exposure. rα-La contained sequential and conformational IgE epitopes. Superposition of IgE-reactive peptides onto the 3-dimensional structure of α-La revealed a close vicinity of the N- and C-terminal peptides within a surface-exposed patch. Conclusions: rα-La can be used for the diagnosis of patients with severe allergic reactions to CM and serves as a paradigmatic tool for the development of therapeutic strategies for CM allergy. © 2010 American Academy of Allergy, Asthma & Immunology

    Patients suffering from non-IgE-mediated cow's milk protein intolerance cannot be diagnosed based on IgG subclass or IgA responses to milk allergens

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    Background: Cow's milk is one of the most common causes of food allergy. In two-thirds of patients, adverse symptoms following milk ingestion are caused by IgE-mediated allergic reactions, whereas for one-third, the mechanisms are unknown. Aim of this study was to investigate whether patients suffering from non-IgE-mediated cow's milk protein intolerance can be distinguished from persons without cow's milk protein intolerance based on serological measurement of IgG and IgA specific for purified cow's milk antigens. Methods: We determined IgG 1-4 subclass and IgA antibody levels to purified recombinant αS1-casein, αS2-casein, β-casein, κ-casein, α-lactalbumin, and β-lactoglobulin in four patient groups by ELISA: Patients with IgE-mediated cow's milk allergy (CMA, n = 25), patients with non-IgE-mediated cow's milk protein intolerance (CMPI, n = 19), patients with gastrointestinal symptoms not associated with cow's milk ingestion (GI, n = 15) and control persons without gastrointestinal problems (C, n = 26). Cow's milk-specific IgE levels were determined by ImmunoCAP. Results: Only CMA patients had IgE antibodies to cow's milk. Cow's milk allergic patients mounted the highest IgG 1 and IgG 4 antibody levels to αS1-casein, αS2-casein, β-casein, κ-casein, and α-lactalbumin. No elevated levels of IgG 4, IgA, and complement-binding IgG subclasses (IgG 1, IgG 2, IgG 3) to purified cow's milk allergens were found within the CMPI patients compared to persons without cow's milk protein intolerance (GI and C groups). Conclusion: Cow's milk protein intolerant patients cannot be distinguished from persons without cow's milk protein intolerance on the basis of IgG subclass or IgA reactivity to cow's milk allergens. © 2011 John Wiley & Sons A/S
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