Effects of enzymatic hydrolysis combined with pressured heating on tree nut allergenicity.

Hazelnut, pistachio and cashew are tree nuts with health benefits but also with allergenic properties being prevalent food allergens in Europe. The allergic characteristics of these tree nuts after processing combining heat, pressure and enzymatic digestion were analyzed through in vitro (Western blot and ELISA) and in vivo test (Prick-Prick). In the analyzed population, the patients sensitized to Cor a 8 (nsLTP) were predominant over those sensitized against hazelnut seed storage proteins (Sprot, Cor a 9 and 14), which displayed higher IgE reactivity. The protease E5 effectively hydrolyzed proteins from hazelnut and pistachio, while E7 was efficient for cashew protein hydrolysis. When combined with pressured heating (autoclave and Controlled Instantaneous Depressurization (DIC)), these proteases notably reduced the allergenic reactivity. The combination of DIC treatment before enzymatic digestion resulted in the most effective methodology to drastically reduce or indeed eliminate the allergenic capacity of tree nuts.

Polarimetric imaging for the detection of synthetic models of SARS-CoV-2: A proof of concept.

Objective: To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging. Approach: Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were prepared in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-µL droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry from87 samples at 405 nm and 514 nm. A polarimetric camera was used for imaging several samples under 380-420 nm illumination at angles similar to those of maximal DLP. Per-pixel image analysis included quantification and combination of polarization feature descriptors in 475 samples. Main results: The angles (from sample surface) of maximal DLP were 3° for 405 nm and 6° for 514 nm. Similar viral particles that differed only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned at 10-degree and 15-degree configurations. Significance: Polarimetric imaging in the visible spectrum may help improve fast, non-contact detection and identification of viral particles, and/or other microbes such as tuberculosis, in multiple dry fluid samples simultaneously, particularly when combined with other imaging modalities. Further analysis including realistic concentrations of real SARS-CoV-2 viral particles in relevant human fluids is required. Polarimetric imaging under visible light may contribute to a fast, cost-effective screening of SARS-CoV-2 and other pathogens when combined with other imaging modalities.

Non-immediate hypersensitivity reactions to iomeprol: Diagnostic value of skin tests and cross-reactivity with other iodinated contrast media.

BACKGROUND: Iodinated contrast media produce non-immediate hypersensitivity reactions (NIHR). The goal of this prospective study was to determine the utility of skin tests and the subsequent tolerance to negative skin-tested iodinated contrasts in patients with NIHR caused by iomeprol. METHODS: Prick and intradermal tests with iomeprol, iopamidol, iopromide, and iobitridol were performed in all patients. IV challenge with the causative contrast (iomeprol in 90%) was made if skin tests were negative. In case of a positive skin test with the causal contrast, or a positive challenge test with it, IV challenge test with an alternative, negative skin-tested contrast was performed in all patients. RESULTS: Skin tests were positive in 47.6% (20/42) of patients with NIHR induced by iomeprol. Of the 66 challenge tests performed with negative skin-tested iodinated contrasts, tolerance was confirmed in 35 (53%): 32 iomeron, 2 iobitridol, 1 iopamidol. Cross-reactivity between iomeprol and iopamidol was 22% (4/20 in patients with positive skin tests and 5/21 in patients with negative skin tests). CONCLUSIONS: Sensitivity of the skin tests was less than 50% NIHRs due to iomeprol, while the negative predictive value of skin tests in patients who tolerated challenges with alternative contrasts (mainly iopamidol) was 53% (35 tolerated out of 66 performed). The cross-reactivity between iomeprol and iopamidol is high.

Optical imaging spectroscopy for rapid, primary screening of SARS-CoV-2: a proof of concept.

Effective testing is essential to control the coronavirus disease 2019 (COVID-19) transmission. Here we report a-proof-of-concept study on hyperspectral image analysis in the visible and near-infrared range for primary screening at the point-of-care of SARS-CoV-2. We apply spectral feature descriptors, partial least square-discriminant analysis, and artificial intelligence to extract information from optical diffuse reflectance measurements from 5 µL fluid samples at pixel, droplet, and patient levels. We discern preparations of engineered lentiviral particles pseudotyped with the spike protein of the SARS-CoV-2 from those with the G protein of the vesicular stomatitis virus in saline solution and artificial saliva. We report a quantitative analysis of 72 samples of nasopharyngeal exudate in a range of SARS-CoV-2 viral loads, and a descriptive study of another 32 fresh human saliva samples. Sensitivity for classification of exudates was 100% with peak specificity of 87.5% for discernment from PCR-negative but symptomatic cases. Proposed technology is reagent-free, fast, and scalable, and could substantially reduce the number of molecular tests currently required for COVID-19 mass screening strategies even in resource-limited settings.

Hyperspectral image processing for the identification and quantification of lentiviral particles in fluid samples.

Optical spectroscopic techniques have been commonly used to detect the presence of biofilm-forming pathogens (bacteria and fungi) in the agro-food industry. Recently, near-infrared (NIR) spectroscopy revealed that it is also possible to detect the presence of viruses in animal and vegetal tissues. Here we report a platform based on visible and NIR (VNIR) hyperspectral imaging for non-contact, reagent free detection and quantification of laboratory-engineered viral particles in fluid samples (liquid droplets and dry residue) using both partial least square-discriminant analysis and artificial feed-forward neural networks. The detection was successfully achieved in preparations of phosphate buffered solution and artificial saliva, with an equivalent pixel volume of 4 nL and lowest concentration of 800 TU·[Formula: see text]L-1. This method constitutes an innovative approach that could be potentially used at point of care for rapid mass screening of viral infectious diseases and monitoring of the SARS-CoV-2 pandemic.

The Expression and Function of CD300 Molecules in the Main Players of Allergic Responses: Mast Cells, Basophils and Eosinophils.

Allergy is the host immune response against non-infectious substances called allergens. The prevalence of allergic diseases is increasing worldwide. However, while some drugs counteract the symptomatology caused by allergic reactions, no completely effective treatments for allergic diseases have been developed yet. In this sense, the ability of surface activating and inhibitory receptors to modulate the function of the main effector cells of allergic responses makes these molecules potential pharmacological targets. The CD300 receptor family consists of members with activating and inhibitory capabilities mainly expressed on the surface of immune cells. Multiple studies in the last few years have highlighted the importance of CD300 molecules in several pathological conditions. This review summarizes the literature on CD300 receptor expression, regulation and function in mast cells, basophils and eosinophils, the main players of allergic responses. Moreover, we review the involvement of CD300 receptors in the pathogenesis of certain allergic diseases, as well as their prospective use as therapeutic targets for the treatment of IgE-dependent allergic responses.

Tolerance to cephalosporins and carbapenems in penicillin-allergic patients

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CD300c costimulates IgE-mediated basophil activation, and its expression is increased in patients with cow's milk allergy.

BACKGROUND: Basophils express high-affinity IgE receptors (FcεRI), which play an essential role in allergic diseases. It is important to characterize new cell-surface receptors that modulate IgE-mediated basophil activation threshold to design promising immunomodulatory therapies. OBJECTIVES: We sought to analyze the expression of CD300 receptors on human basophils and their implication in IgE-mediated basophil activation processes. METHODS: Blood samples from healthy subjects and patients with cow's milk allergy were collected through the Basque Biobank under an institutional review board-approved protocol. PBMCs were obtained by means of density centrifugation, basophils were purified with a specific isolation kit, and phenotypic and functional studies were performed by using flow cytometry. RESULTS: We demonstrate that basophils express the activating receptor CD300c, which is specifically upregulated in response to IL-3. CD300c works as a costimulatory molecule during IgE-mediated basophil activation, as shown by a significant increase in degranulation and cytokine production when basophils are activated in the presence of CD300c cross-linking compared with activation through the IgE/FcεRI axis alone. Coligation of FcεRI and CD300c increased intracellular calcium mobilization and phosphorylation of signaling intermediates evoked only by FcεRI ligation. We show that the natural ligands of CD300c, phosphatidylserine and phosphatidylethanolamine, modulate IgE-mediated basophil activation. Furthermore, we have observed that CD300c expression in children with cow's milk allergy is increased compared with that in healthy control subjects and that the intensity of expression correlates with the severity of the hypersensitivity symptoms. CONCLUSION: CD300c could be considered a biomarker and therapeutic target in patients with IgE-mediated allergic diseases because it seems to be involved in the modulation of IgE-mediated basophil activation.

Lipid Transfer Protein Syndrome in a Non-Mediterranean Area.

BACKGROUND: Plant food allergies associated with lipid transfer protein (LTP) have been widely described in the Mediterranean Basin. OBJECTIVE: The aim of this work was to describe the clinical profile and pollen sensitization of plant food- allergic patients sensitized to LTP in a non-Mediterranean area. METHODS: Patients with clear IgE-mediated symptoms associated with plant foods and a positive skin prick test (SPT) to Pru p 3 were included in a prospective study in the north of Spain. Reported symptoms were analyzed together with a battery of food and pollen SPTs and specific IgE components by ISAC microarray. Cross-inhibition studies were performed by ImmunoCAP with plane tree, mugwort and rPru p 3. RESULTS: Among the 72 patients included, the most frequent food allergy reported was to peaches (69%) followed by nuts (walnuts 55%, peanuts 54% and hazelnuts 43%). Most patients suffered from symptoms with multiple plant foods (a median of 6 foods per patient). Regarding the patients' pollen sensitization, 36% were sensitized to mugwort pollen (72% showing sIgE to Art v 3), 33% to grass pollen and 24% to plane tree pollen (94% with sIgE to Pla a 3). Inhibition studies showed that specific IgEs against mugwort and plane tree pollen are inhibited by Pru p 3 in a strong manner, whereas Pru p 3 was less inhibited by pollen extracts. CONCLUSIONS: LTP syndrome occurs in a non-Mediterranean area and is related to multiple sensitizations to foods and pollens such as plane tree and mugwort. In these pollen sensitizations, Pru p 3 seems to be the primary sensitizer.

Pollensomes as Natural Vehicles for Pollen Allergens.

Olive (Olea europaea) pollen constitutes one of the most important allergen sources in the Mediterranean countries and some areas of the United States, South Africa, and Australia. Recently, we provided evidence that olive pollen releases nanovesicles of respirable size, named generically pollensomes, during in vitro germination. Olive pollensomes contain allergens, such as Ole e 1, Ole e 11, and Ole e 12, suggesting a possible role in allergy. The aim of this study was to assess the contribution of pollensomes to the allergic reaction. We show that pollensomes exhibit allergenic activity in terms of patients' IgE-binding capacity, human basophil activation, and positive skin reaction in sensitized patients. Furthermore, allergen-containing pollensomes have been isolated from three clinically relevant nonphylogenetically related species: birch (Betula verrucosa), pine (Pinus sylvestris), and ryegrass (Lolium perenne). Most interesting, pollensomes were isolated from aerobiological samples collected with an eight-stage cascade impactor collector, indicating that pollensomes secretion is a naturally occurring phenomenon. Our findings indicate that pollensomes may represent widespread vehicles for pollen allergens, with potential implications in the allergic reaction.

Decrease in antigen-specific CD63 basophil expression is associated with the development of tolerance to egg by SOTI in children.

BACKGROUND: In the last decade, there have been an increasing number of studies on achieving tolerance to foods by specific oral tolerance induction (SOTI). Still, the underlying mechanism of SOTI is unknown. Our aim was to describe changes in CD63 expression on basophils following in vitro Ag-specific stimulation by basophil activation test (BAT), after SOTI with egg in a pediatric population. METHODS: Ten children with persistent allergy to egg were included. Skin prick tests (SPTs) and open food challenges (OFCs) were performed before SOTI. Specific IgE determination and BAT with egg white (EW), ovomucoid (OM), and ovalbumin (OVA) were performed before and after 1 month of the buildup phase of SOTI. RESULTS: Total tolerance to egg was achieved in 9 cases and partial in one. After SOTI, there was a significant decrease in mean specific IgE levels (p < 0.05). CD63 expression also decreased (p < 0.05) in all patients. CONCLUSION: Decrease in Ag-specific basophil responsiveness is associated with the development of clinical tolerance by SOTI.

Graph based study of allergen cross-reactivity of plant lipid transfer proteins (LTPs) using microarray in a multicenter study.

The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens.