Serum Histamine Research Articles

Gastrointestinal symptoms in children with mastocytosis

Introduction. Mastocytosis is a heterogeneous group of diseases characterized by the abnormal accumulation of clonal mast cells (MCs) in various tissues and organs, including skin, bone marrow, liver, spleen and lymph nodes. The clinical picture of cutaneous and indolent systemic mastocytosis is formed by a wide range of symptoms associated with activation of mast cells. Single European studies have demonstrated wide variability in the frequency of gastrointestinal symptoms (GI-symptoms)) in children with mastocytosis (from 15 to 50%).Aim. To analyze the frequency of mediator-related GI-symptoms in children with different subtypes and clinical forms of mastocytosis.Materials and methods. A prospective observational study included data from 289 children aged 3 to 17 years who were under observation at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology. Symptoms were assessed using the Pediatric grade scale of symptoms of mastocytosis. Clinical manifestations of reactions caused by mast cell degranulation were compared with data from clinical and laboratory studies. The concentrations of tryptase and histamine in the blood serum of patients were determined. The incidence of organomegaly and mesenteric lymphadenitis in children with mediating symptoms and without symptoms was determined using ultrasound.Results. 67 (23.2%) patients had GI symptoms. More than half of the patients (51.6%) indicated abdominal pain, 32.3% reported diarrhea. The severity of pain symptoms correlated with the level of serum tryptase (ρ = 0.564, p < 0.01). The incidence of hepatomegaly and mesadenitis in children with GI- symptoms was 19.4% and 25.4%, respectively. In a comparative analysis in groups of children with and without GI symptoms, the differences in the number of identified cases of organomegaly and mesadenitis were statistically significant (p < 0.001). An increase in histamine levels in the blood was detected in half of the patients with complaints of heartburn and nausea.Conclusion. Our results demonstrated that a study of the level of serum tryptase, ultrasound of the abdominal organs and lymph nodes should be carried out in all children with mediator-related GI-symptoms regardless of the clinical form of mastocytosis.

BPIFA1 alleviates allergic rhinitis by regulating the NF-κB signaling pathway and Treg/Th17 balance.

Allergic rhinitis (AR) is an allergic condition characterized by inflammation of the nasal mucosa. Bacterial permeability-increasing family member A1 (BPIFA1) exhibits anti-inflammatory properties; however, its impact on AR remains unclear. Aim of this study is to investigate the expression and function of BPIFA1 in AR and its influence on inflammation and immune regulation in a mouse model of AR induced by ovalbumin (OVA). The expression of BPIFA1 was analyzed using quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC). Morphological assessments of nasal mucosal tissues were conducted. Levels of inflammatory mediators in nasal lavage fluid (NALF) and serum were quantified using enzyme-linked immunosorbent assay (ELISA) kits. Protein expressions of BPIFA1, phosphorylated and total p65 (p-p65/p65), and IκBα were evaluated through Western blot analysis. The total cell counts, including epithelial cells, eosinophils, and lymphocytes in NALF, were determined using a hemocytometer. A mouse model of AR was established by OVA management. BPIFA1 expression was found to be reduced in the nasal mucosa tissues of patients with AR, suggesting a potential role in the disease's progression. We successfully developed a mouse model of AR, where BPIFA1 was similarly downregulated, indicating its possible involvement in modulating the NF-κB signaling pathway. Overexpression of BPIFA1 in this model attenuated inflammation and allergic responses by inhibiting the NF-κB pathway. Additionally, overexpression of BPIFA1 promoted the differentiation of regulatory T cells (Treg) and inhibited the differentiation of T helper 17 cells (Th17) in the NALF of AR mice, further demonstrating its regulatory impact on immune responses. The study confirmed that BPIFA1 upregulation reduced the levels of inflammatory cytokines TNF-α and IL-6, decreased infiltration of inflammatory cells, and modulated antigen-specific immunoglobulin levels and histamine in serum. BPIFA1 mitigated both inflammatory and allergic responses in AR mice induced by OVA through the modulation of the NF-κB signaling pathway and the balance between regulatory T cells (Treg) and T helper 17 cells (Th17). These findings suggest that BPIFA1 could serve as a novel biomarker and therapeutic target for AR, offering potential for the development of targeted treatments to improve patient outcomes.

Prevention and alleviation of allergic rhinitis by oral administration of Lacticaseibacillus paracasei GOLDGUT-Lpc969.

Allergic rhinitis (AR) is a widespread upper airway disorder characterized by inflammation of the nasal passages. It is immunologically mediated via the hypersensitivity type I mechanism, which is primarily elicited by the immunoglobulin E (IgE)-linking allergen-induced imbalance of the Th2/Th1 immune response. Owing to the limited efficacy of current medications, probiotics have received attention for their potential in preventing and ameliorating AR. In this study, a Lacticaseibacillus paracasei strain, GOLDGUTLpc969 (Lpc969), isolated from the feces of healthy adults, was proven to be effective in preventing AR by LPA-induced RBL-2H3 in-vitro and OVA-induced AR mice in-vivo evaluation. The strain significantly attenuated the release of histamine and degranulation in LPS-induced RBL-2H3 cells. In the OVA-induced AR mice, L. paracasei GOLDGUT-Lpc969 also exhibited a significant decrease in disease indicators such as the disease activity index (DAI score), serum IgE, and serum histamine. Treatment with L. paracasei GOLDGUT-Lpc969 led to significant suppression of the Th2-related cytokines IL-4, IL-5, IL-6, IL-13, and TNF-α in the serum of mice. Furthermore, a comparison of the genomes of three previously reported AR-effective L. paracasei strains (including GOLDGUTLpc969) and one non-effective L. paracasei strain revealed that the gene K03671 may play a key role in alleviating AR symptoms. In conclusion, this study highlights the efficacy of L. paracasei GOLDGUT-Lpc969 in AR prevention by suppressing the Th2 immune response and proposes the potential involvement of the functional gene K03671 in ameliorating AR symptoms. Therefore, L. paracasei GOLDGUT-Lpc969 shows promise as a probiotic for preventing AR.

The influence on the structure and allergenicity of milk β-lactoglobulin by methylglyoxal during thermal processing

This study aims to investigate the effects of the typical glycation intermediate methylglyoxal (MGO) on the structure and allergenicity of milk β-lactoglobulin (βLG) during thermal processing. Structural changes were assessed using SDS-PAGE, intrinsic fluorescence, circular dichroism, and HPLC-MS/MS. Allergenicity was evaluated through in vitro and in vivo experiments. The conformational changes of βLG significantly were induced by MGO during heat treatment, with a 41.3% decrease in α-helix content and a 25.4% increase in random structure. Furthermore, the lysine, arginine, aspartic acid, and histidine residues in βLG were modified by MGO, which may disrupt or mask allergenic epitopes. Additionally, MGO treatment resulted in a reduction of 41.1% and 26.8% in the pro-inflammatory mediators histamine and β-hexosaminidase in KU812 cells, respectively. Additionally, cytokine levels of IL-4 and IL-13 were reduced by 26.3% and 21.75%, respectively. In mouse experiments, compared to the βLG group, the MGO-βLG group showed a 2–4 fold decrease in IgE, IgG, and IgG1 levels. After reacting with βLG, MGO can reduce serum histamine release by up to 73.9% and mast cell protease-1 (MCP-1) release by 40.8%. These results indicate that the typical glycation intermediate MGO can modify the allergenic epitopes of milk βLG during thermal processing, thereby affecting its allergenicity. This study provides a reference for elucidating the natural rules of allergenicity changes during milk thermal processing.

Guaijaverin and Epigallocatechin Gallate Complex Modulate Th1 and Th2 Cytokine-Mediated Allergic Responses Through STAT1/T-bet and STAT6/GATA3 Pathways.

We aimed to determine the in vitro and invivo synergistic antiallergic effect of guaijaverin and epigallocatechin gallate (EGCG) complex (GEC), and the antiallergic rhinitis (AR) properties of guaijaverin-rich Psidium guajava and EGCG-rich Camellia sinensis (ILS-F-2301). GEC showed synergistic inhibition of β-hexosaminidase by 4.20% and interleukin (IL)-4, -5, and -13 by 4.08%, 0.67%, and 4.71%, respectively, while increasing interferon (IFN)-γ by 12.43%, compared with EGCG only. In addition, 50 μg/mL of ILS-F-2301 inhibited β-hexosaminidase release, and inhibited IL-4, -5, and -13 by 61.54%, 58.79%, and 59.25%, respectively, while increasing IFN-γ (showing 133.14% activation). Moreover, 50 μg/mL of ILS-F-2301 suppressed p-STAT6 and GATA3, while p-STAT1 and T-bet increased, and 0.039 μg/mL of guaijaverin or 5.275 μg/mL of EGCG modulated T helper (Th)1- and Th2-related proteins. These data suggested that guaijaverin and EGCG in ILS-F-2301 was the main active compound involved in Th1/Th2 modulation. In the AR mouse model, the administration of ILS-F-2301 inhibited ovalbumin (OVA)-specific IgE, histamine in serum; it also inhibited IL-4 and -5 by 28.23% and 47.15%, respectively, while increasing IFN-γ (showing 37.11% activation), compared with OVA/Alu-treated mice. Taken together, our findings suggest that ILS-F-2301 is a functional food for alleviating anti-AR.

Inhibition of pseudo-allergic reactions by vitamin K3 directly targeting GAB1 in mast cells

BackgroundVitamin K3 (VK3), a fat-soluble synthetic analog of the vitamin K family, has coagulant, anti-inflammatory, antibacterial, and anticancer properties. Pseudo allergy is a IgE-independent immune response associated with mast cells. This study investigated the role of VK3 in IgE-independent mast cell activation. MethodsSubstance P (SP) was used to induce LAD2-cell activation in order to analyze the effects of VK3 in vitro. Cutaneous allergy and systemic allergy mouse models were used to analyze the anti-pseudo-allergic effects of VK3. Proteome microarray assays were used to analyze VK3-binding protein. Biolayer interferometry and immunoprecipitation were used to verify interaction between VK3 and its key targets. RNA interference was used to determine the role of GAB1 in LAD2cell activation. ResultsVK3 inhibited SP-induced LAD2-cell activation, and resulted in the release of β-hexosaminidase, histamine and cytokines; VK3 inhibited SP-induced pseudo allergic reactions in mice, and serum histamine and TNF-α levels decreased. Degranulation of skin mast cells was reduced; GAB1 in mast cells was stably bound to VK3. GAB1 participated in SP-induced LAD2-cell activation. GAB1 knockdown in LAD2 cells prevented SP-induced β-hexosaminidase release, calcium mobilization and cell skeletal remodeling. VK3 directly binds to GAB1 and reduces its expression to inhibited SP-induced LAD2 cell activation. ConclusionThe anti-pseudo-allergic activity of VK3 was confirmed in vitro and in vivo. VK3 can inhibit SP-induced mast cell activation by directly targeting GAB1. This study provides new insights on the activity of VK3 and the mechanism of pseudoallergic reaction.

Cang-ai volatile oil alleviates nasal inflammation via Th1/Th2 cell imbalance regulation in a rat model of ovalbumin-induced allergic rhinitis.

We previously revealed that Cang-ai volatile oil (CAVO) regulates T-cell activity, enhancing the immune response in people with chronic respiratory diseases. However, the effects of CAVO on allergic rhinitis (AR) have not been investigated. Herein, we established an ovalbumin (OVA)-induced AR rat model to determine these effects. Sprague-Dawley (SD) rats were exposed to OVA for 3weeks. CAVO or loratadine (positive control) was given orally once daily for 2weeks to OVA-exposed rats. Behavior modeling nasal allergies was observed. Nasal mucosa, serum, and spleen samples of AR rats were analyzed. CAVO treatment significantly reduced the number of nose rubs and sneezes, and ameliorated several hallmarks of nasal mucosa tissue remodeling: inflammation, eosinophilic infiltration, goblet cell metaplasia, and mast cell hyperplasia. CAVO administration markedly upregulated expressions of interferon-γ, interleukin (IL)-2, and IL-12, and downregulated expressions of serum tumor necrosis factor-α, IL-4, IL-5, IL-6, IL-13, immunoglobulin-E, and histamine. CAVO therapy also increased production of IFN-γ and T-helper type 1 (Th1)-specific T-box transcription factor (T-bet) of the cluster of differentiation-4+ T-cells in splenic lymphocytes, and protein and mRNA expressions of T-bet in nasal mucosa. In contrast, levels of the Th2 cytokine IL-4 and Th2-specific transcription factor GATA binding protein-3 were suppressed by CAVO. These cumulative findings demonstrate that CAVO therapy can alleviate AR by regulating the balance between Th1 and Th2 cells.

Ameliorative potential of galangin in murine model of ovalbumin-induced allergic rhinitis: a role of PI3K-PKB pathway.

To examine the potential of galangin in a mouse model of ovalbumin (OVA)-induced allergic rhinitis (AR), as chronic AR, induced by immunoglobulin-E (IgE), leads to histamine release and nasal inflammation, and although galangin exhibits antiasthmatic and anti-inflammatory potential, its effect on AR is yet to be investigated. 126 BALB/c mice. AR induction involved sensitizing female mice with OVA (5%, 500 µL, IP) for 14 days. Post OVA challenge, the mice were divided into 7 groups (n = 18/group), including normal, AR control, montelukast (10 mg/kg), galangin (5, 10, and 20 mg/kg), and per se (galangin [20 mg/kg] treatment. Various outcomes were evaluated, including nasal symptoms, histopathology, biochemistry, and nasal lavage fluid inflammatory cytokines and signaling pathways in nasal mucosal to assess galangin potential in AR. In AR mice, galangin (10 and 20 mg/kg) significantly (P < .05) reduced sneezing, rubbing, and nasal discharge post-OVA challenge. Galangin treatment attenuated (P < .05) elevated serum histamine, β-hexosaminidase, IgE, and Immunoglobulin G1 levels in AR control mice. Additionally, galangin significantly (P < .05) decreased OVA-induced alterations in IL-4, IL-6, IL-13, and interferon-γ levels in nasal lavage fluid compared to AR control mice. Western blot analysis demonstrated that galangin lowered OVA-induced AR by significantly (P < .05) downregulating the phosphorylated protein kinase B and mammalian target of rapamycin-protein expressions while markedly (P < .05) upregulating the glycogen synthase kinase-3β protein expressions in nasal mucosal. Galangin also significantly ameliorated (P < .05) the OVA-induced histological aberrations in the nasal mucosa, reflected by reduced eosinophil infiltration, hyperplasia, and edema. Galangin exhibits antihistaminic and anti-inflammatory effects in AR mice by regulating IgE-mediated histamine and inflammatory release and modulating the phosphatidylinositol 3-kinase/Ak strain transforming/mammalian target of rapamycin pathways.

Ethanol Extract of Ampelopsis brevipedunculata Rhizomes Suppresses IgE-Mediated Mast Cell Activation and Anaphylaxis.

More than 20% of the world's population suffers from allergic diseases, including allergic asthma, rhinitis, and atopic dermatitis that severely reduce the patient's quality of life. The treatment of allergy has been developed, but there are still unmet needs. Ampelopsis brevipedunculata (Maxim.) Trautv. is a traditional medicinal herb with beneficial bioactivities, such as antioxidant, anti-hypertension, anti-viral, anti-mutagenic, and skin and liver (anti-hepatotoxic) protective actions. However, its anti-allergic effect has not been addressed. This study designed to investigate the pharmacological effect of an ethanol extract of A. brevipedunculata rhizomes (ABE) on mast cell and anaphylaxis models. For in vivo studies, we used ovalbumin-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models. In ASA model, oral administration of ABE (1, 10, and 100 mg/kg) attenuated the anaphylactic responses, such as hypothermia, serum histamine, and IgE productions. In PCA model, ABE also suppressed the plasma extravasation and swelling. The underlying mechanisms of action were identified in various mast cell types. In vitro, ABE (10, 30, and 60 µg/mL) inhibited the release of essential allergic mediators, such as histamine and β-hexosaminidase, in a concentration-dependent manner. ABE prevented the rapid increase in intracellular calcium levels induced by the DNP-HSA challenge. In addition, ABE downregulated the tumor necrosis factor-α and interleukin-4 by suppressing the activation of nuclear factor-κB. Collectively, this study is the first to identify the anti-allergic effect of ABE, suggesting that ABE is a promising candidate for treating allergic diseases.

Mahuang Fuzi Xixin decoction alleviates allergic rhinitis by inhibiting NLRP3/Caspase-1/GSDMD-N-mediated pyroptosis

Ethnopharmacological relevanceAllergic rhinitis (AR) is a prevalent nasal inflammatory disorder, and pyroptosis plays a crucial role in aggravating AR. Current medications for AR treatment still have deficiencies, and finding new agents is of great interest. Mahuang Fuzi Xixin decoction (MFXD), an ancient Chinese medicine, is now commonly used to treat AR, which has anti-inflammatory and immunomodulatory effects, but its underlying mechanism is unknown. Aim of this studyThis study aims to evaluate the effects of MFXD on AR and explore its potential mechanisms in view of the regulatory effect on pyroptosis. MethodsMFXD, Mahuang, Fuzi, and Xixin water extracts were analyzed using ultra high performance liquid chromatography-Orbitrap-high-resolution accurate mass spectrometry. In in vivo study, the effects of MFXD on AR treatment were evaluated in an ovalbumin-induced mouse model. Mice were administered saline (control and model groups), MFXD (1.375, 2.75 g/kg), and dexamethasone (2.5 mg/kg) for 13 days. AR symptoms were evaluated by blinded observers. Immunoglobulin E (IgE) and histamine levels were measured using enzyme-linked immunosorbent assays. Expression of pyroptosis-related proteins (NLRP3, ASC, Caspase-1 p10/p20, GSDMD-N and IL-1β) in AR mouse nasal mucosa were estimated by immunohistochemistry. In in vivtro study, the effects of MFXD on pyroptosis were assessed in human nasal epithelial cells (HNEpCs) stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP), and incubated with MFXD (12.5, 25, and 50 μg/mL). Pyroptosis-related protein expression was measured by western blotting. ResultsThirty-three compounds in MFXD were identified, including ephedrine, pseudoephedrine, higenamine, aconine, aconitine, benzoylmesaconitine, benzoylhypaconine and hypaconitine. In the in vivo study, oral taken of MFXD/dexamethasone significantly ameliorated AR symptoms, reduced swelling of the nasal mucosa, and decreased the levels of IgE and histamine in AR mice serum. MFXD/dexamethasone attenuated histopathological changes and reduced the expression of pyroptosis-related proteins in nasal mucosa, indicating the inhibitory effect on nasal epithelial pyroptosis. In the in vitro study, MFXD (50 μg/mL) significantly alleviated cytotoxicity, protected cells from swelling and rupture, and downregulated the expression of pyroptosis-related proteins in LPS/ATP-induced HNEpCs. ConclusionMFXD suppressed nasal epithelial pyroptosis by inhibiting the NLRP3/Caspase-1/GSDMD-N signaling pathway, which alleviates AR. Our results offer valuable insights into potential AR therapies and provide evidence for the clinical utilization of MFXD to treat AR.

Surgical treatment of bovine nasal granuloma and an allergological exploration.

Nasal granuloma in cattle results from inflammation within, and attendant proliferation of, the nasal mucosa possibly in response to an allergic response. However, the relationship between nasal granuloma and allergies remains unclear. Furthermore, severe cases have a poor prognosis because there is currently no effective treatment. Herein, we report three cases of nasal granuloma with severe stertorous breathing that were treated surgically. We also conducted an allergological exploration. Following surgical removal clinical signs did not recur in two of the three cases; however, stertorous breathing persisted in one case, and the cow was sacrificed 4 months later. A histopathological examination revealed that all nasal granulomas featured varying infiltrations of macrophages eosinophils, mast cells, and lymphocytes. The number of mast cells and the proportion of these cells that had degranulated were significantly higher in the granulomas than in normal nasal mucosae. In addition, serum histamine levels were higher in nasal granuloma cases than in normal cows, although serum immunoglobulin E levels were similar, and lymphocyte infiltration in the submucosal layer suggested type I and type IV allergies. Collectively, the results indicate the efficacy of complete surgical curettage for the treatment of allergic nasal granuloma in cattle. Further studies are required to identify the causes and risk factors of allergic nasal granuloma in cows.

Oral Ingestion of Yuzu Seed Oil Suppresses the Development of Atopic Dermatitis-like Skin Lesions in NC/Nga Mice.

Long-term oral ingestion of unheated yuzu seed oil in humans reduces lipid peroxides in the blood. Moreover, yuzu seed oil contains limonin, which can induce antioxidant and anti-inflammatory effects by activating the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). Previously, Nrf2 has been shown to reduce atopic dermatitis (AD). Therefore, we hypothesized that ingesting unheated yuzu seed oil can regulate AD through Nrf2. An AD model was established using NC/Nga mice through repeated local exposure to mite antigens. Unheated and purified yuzu seed oil (100 µL/mice) or water (control, 100 µL/mice) was administered orally once a day using a gastric cannula for rodents for 28 days. On day 28, mice in the unheated yuzu seed oil group exhibited significantly lower clinical skin severity scores and ear thickness than those in the purified yuzu seed oil and water groups. Serum histamine levels remained unaltered among the three AD-induced groups. Serum Dermatophagoides farina body (Dfb)-specific immunoglobulin E (IgE) levels were significantly lower in the unheated yuzu seed oil group. Oral ingestion of yuzu seed oil in NC/Nga AD model mice significantly suppressed dermatitis deterioration and decreased serum IgE levels. Clinical trials (n = 41) have already confirmed that unheated yuzu oil is safe for long-term intake, further suggesting its potential use in improving AD symptoms.

Blockade of exosome release alleviates the hypersensitive reaction by influencing the T helper cell population in cow's milk allergic mice.

The aim of this work was to evaluate the ameliorative effects of exosome biogenesis in cow's milk allergy (CMA) response. In this context, BALB/c mice were systemically sensitized with cow's milk proteins plus an aluminum adjuvant to induce CMA. The inhibitor GW4869 of exosome biogenesis was added before sensitization and then the anaphylactic reactions were evaluated both in vivo (clinical score and body temperature) and in vitro (serum histamine, allergen-specific antibodies, cytokines by ELISA and cell analysis by flow cytometry) to explore the role of exosomes in the development of CMA. Nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) showed that the size distribution and morphology of CMA-derived exosomes were not changed after GW4869 preconditioning, and the concentration of exosomes was much lower than that of the CMA group. In the GW4869 group, inhibition of release of exosomes modulated the induction of T helper 2 cell (Th2)-related substances, with a decrease in histamine and allergen-specific immunoglobulin (Ig) E, and the expression of Th1, Th2, and Th17 cells all decreased as well. Moreover, the experimental data were integrated by means of principal component analysis (PCA) to give an overview that the percentage of Th cells and concentrations of cytokines were more influenced by GW4869 treatment. These data for the first time demonstrated that exosomes are involved in the development of CMA and the blockade of exosome release with GW4869 suppressed the IgE-mediated immune response in CMA.

Both live and heat killed Lactiplantibacillus plantarum DPUL-F232 alleviate whey protein-induced food allergy by regulating cellular immunity and repairing the intestinal barrier.

Postbiotics have been proposed as clinically viable alternatives to probiotics, addressing limitations and safety concerns associated with probiotic use. However, direct comparisons between the functional differences and health benefits of probiotics and postbiotics remain scarce. This study compared directly the desensitization effect of probiotics and postbiotics derived from Lactiplantibacillus plantarum strain DPUL-F232 in the whey protein-induced allergic rat model. The results demonstrate that administering both live and heat killed F232 significantly alleviated allergy symptoms, reduced intestinal inflammation, and decreased serum antibody and histamine levels in rats. Both forms of F232 were effective in regulating the Th1/Th2 balance, promoting the secretion of the regulatory cytokine IL-10, inhibiting mast cell degranulation and restoring the integrity of the intestinal barrier through the upregulation of tight junction proteins. Considering the enhanced stability and reduced safety concerns of postbiotics compared to probiotics, alongside their ability to regulate allergic reactions, we suggest that postbiotics may serve as viable substitutes for probiotics in managing food allergies and potentially other diseases.

Exploring immune response and lab markers across COVID-19 severity levels

&lt;p&gt;This retrospective cohort study investigated antigen-specific antibody responses to SARS-CoV-2 and laboratory markers in coronavirus disease 2019 (COVID-19) patients of varying severities. Serum or plasma samples collected early in the pandemic were analyzed for the presence of IgG antibodies and IgG subclasses which target the recombinant spike (S) and nucleocapsid (N) proteins of SARS-CoV-2. Correlation analyses were conducted to assess the possible relationship between the IgG subclasses to SARS-CoV-2 proteins, inflammatory markers, and the severity of the disease. It was shown that the severity of the disease positively correlated with the C-reactive protein (CRP), but most of all with the neutrophil/lymphocyte ratio (NLR) levels. IgG titers against the S- and N-proteins decreased in the most severe COVID-19 cases, which potentially attributed to a delayed IgG formation compared to milder infections. The presence of anti-spike IgG displayed a medium negative correlation trend (not statistically significant, which might be due to the small sample size in our study) with laboratory markers (such as CRP, Fibrinogen, Degree) which are suggestive of infection severity. anti-S IgG correlated positively but weakly with the serum histamine levels. The presence of anti-N IgG at the time of hospitalization correlated with the subsequent outcome. At the same time, anti-N IgG1 correlated with the detection of the viral RNA in the blood. Thus, seroconversion may occur later in patients with a more severe pneumonia. The summary data suggests correlations between the expression of inflammatory markers and the antibody responses, which can also serve as early clinical markers.&lt;/p&gt;

Exploring fibrous ingredients for fish: The case of feeding sugar beet pulp to tambaquí (Colossoma macropomum)

For a long time, co-products of food processing have been used in animal feed, but far less in fish because of their assumed inability to cope with high-fiber diets. Research on feeding co-products to fish species that naturally consume fibrous diets are yet lacking. We here evaluated the impact of sugar beet pulp in the diet of tambaquí on nutrient metabolism, oxidative stress, inflammation, and intestinal histomorphometry. A total of 18 tambaquí fish (1616 ± 107 g; 2 years old) were randomly divided over 6 similar tanks with 3 fish per tank and randomly attributed to one of the six dietary treatments 0, 5, 10, 15, 20 and 25 % beet pulp addition and reared for 8 weeks. Water quality parameters (pH, NH3–N, EC, TDS, DO, and temperature) were assessed and recorded twice a week for each tank. A quadratic increase in intestinal villus length, paravilli and absorptive surface were observed with beet pulp addition. Ammonia and pH as quality indicators were significantly changing with beet pulp addition. A higher supply of glucogenic substrate to the citric acid cycle was noticed with beet pulp addition due to the positive correlation with blood propionylcarnitine: acetylcarnitine ratio while there was no effect on ketone body synthesis as measured through the 3-hydroxybutyrylcarnitine: acetylcarnitine ratio. No pronounced change of serum and whole fish histamine and lowered concentrations of serum malondialdehyde were observed with beet pulp addition. In conclusion, beet pulp induced a marked increase in intestinal villus architecture without signs of inflammation or oxidative stress. Large-scale studies need to clarify if these features lead to improved growth performance but this work opens options for further study. The non-linear pattern of some blood components with increasing beet pulp may call for future optimal dosing and feed form of beet pulp together.

Intrinsic self-calibration electrostatic-controlled ratiometric fluorescence assay of histamine in human serum and canned tuna fish samples

Bimetallic nanoclusters protected by proteins have gained significant attention in the sensing field due to their aggregation-induced emission (AIE) property. However, their applications may be restricted by the effects of temperature, pH, ethanol, and metal ions. Therefore, the development of self-assembling technology could increase the potential applications of these materials. In this study, positively charged silicon nanoparticles (SiNPs) were mixed with negatively charged bovine serum albumin-protected silver doped gold nanoclusters (BSA@AgAuNCs) through an electrostatic interaction. The resulting system exhibited dual emissions at 610 nm ((BSA@AgAuNCs) and 460 nm (SiNPs) when excited at 370 nm. The mixing of SiNPs led to an increase in the fluorescence emission of BSA@AgAuNCs due to an aggregation-induced emission (AIE) enhancement. However, the addition of histamine, which is positively charged at pH 5.5, caused the SiNPs to be triggered and adsorbed onto the surface of BSA@AgAuNCs, resulting in their disaggregation and a decrease in their fluorescence emission. Simultaneously, the blue fluorescence emission of SiNPs at 460 nm was not affected and remained unchanged. Under optimized conditions, the fluorescence response (F460/F610) showed a linear increase with the concentration of histamine in the range of 0.01–80 µM, with a detection limit (S/N = 3) of 3.0 nM. The probe demonstrated excellent sensitivity, selectivity, and reliability in quantifying histamine in complex matrices. The recoveries % values are in the range of 97–102% and 97.7–104.4% with RSD % in the range of 2.67–3.98% and 2.78–4.00% for human blood serum and canned tuna fish samples, respectively. This work presents new opportunities for the development of sensors based on self-assembling and dual emissive properties for (bio) sensing applications.

Placebo-Controlled Histamine Challenge Disproves Suspicion of Histamine Intolerance

Histamine intolerance (HIT) is frequently diagnosed in patients with polysymptomatic otherwise unexplained symptoms. To exclude HIT by a single-blind placebo-controlled histamine challenge (SBPCHC), to study clinical features of patients with positive challenge, and to examine the predictability of HIT by biomarkers. SBPCHC was performed in 59 patients with suspected HIT. History and clinical data, including serum diamine oxidase (DAO) and histamine skin test wheal size of patients with positive versus negative SBPCHC, were compared. Patients were predominantly middle-aged women (84.7%). Three-quarters reported improvement but never resolution of symptoms during a histamine-low diet. Histamine provocation was safe; only 1 patient was treated with antihistamines. Thirty-seven patients (62.7%) displayed symptoms to placebo. HIT was excluded in 50 patients (84.7%). Objective symptoms occurred in 4 of 59 cases (6.8%) after histamine but not after placebo challenge. These were diagnosed with "plausible HIT" because reactions occurring by chance could not be excluded. Another 5 patients (8.5%) were diagnosed with "possible HIT" after case-dependent detailed analysis. Patients with plausible/possible HIT had reported more gastrointestinal symptoms (P= .01), but comparable diet response and equal histamine skin prick test wheal sizes to those without HIT. Serum DAO activity tended to be lower in patients with HIT (P= .08), but was highly variable in those without, limiting its value as a biomarker. SBPCHC disproves HIT in the majority of patients. Placebo-controlled challenges are needed as placebo reactions were frequent. Gastrointestinal symptoms after food intake and reduced DAO levels are markers for HIT; however, specificity is not sufficient enough for making the diagnosis.

Resistant potato starch supplementation reduces serum histamine levels in healthy adults with links to attenuated intestinal permeability

Histamine from our diet or gut microbes can trigger gastrointestinal disturbances, and resistant potato starch (RPS) has previously been shown to alleviate these symptoms while increasing levels of health-associated bacteria such as Akkermansia through unknown mechanisms. Post hoc exploratory metabolomic analysis of serum amino acid, amine, and carnitine metabolites in participants consuming 3.5 g/day RPS or placebo (n = 48) was performed using liquid chromatography-mass spectrometry to determine whether RPS positively influences histamine metabolism and related parameters. Histamine levels were significantly reduced by RPS treatment, but histamine-degrading enzyme products were unaffected by RPS. RPS also reduced histamine-secreting Haemophilus and Lactobacillus. Further, metabolites associated with intestinal permeability, including 5-hydroxylysine, acetylspermidine, and short- and medium-chain carnitines ratios, were significantly reduced by RPS treatment, suggesting decreased serum histamine might be related to enhanced gut barrier function. These metabolomic findings expand the value of supplementing the diet with RPS.

Secreted phosphoprotein 1 regulates natural compound 3’,4’,5,7-tetrahydroxyflavone to inhibit mast cell-mediated allergic inflammation

BackgroundMast cells (MCs) are important effector cells in anaphylaxis and anaphylactic disease. 3’,4’,5,7-tetrahydroxyflavone (THF) presents in many medicinal plants and exerts a variety of pharmacological effects. In this study, we evaluated the effect of THF on C48/80-induced anaphylaxis and the mechanisms underlying its effects, including the role of secreted phosphoprotein 1 (SPP1), which has not been reported to IgE-independent MC activation.ResultsTHF inhibited C48/80-induced Ca2+ flow and degranulation via the PLCγ/PKC/IP3 pathway in vitro. RNA-seq showed that THF inhibited the expression of SPP1 and downstream molecules. SPP1 is involved in pseudo-anaphylaxis reactions. Silencing SPP1 affects the phosphorylation of AKT and P38. THF suppressed C48/80-induced paw edema, hypothermia and serum histamine, and chemokines release in vivo.ConclusionsOur results validated SPP1 is involved in IgE-independent MC activation anaphylactoid reactions. THF inhibited C48/80-mediated anaphylactoid reactions both in vivo and in vitro, suppressed calcium mobilization and inhibited SPP1-related pathways.