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  • 1985-1989  (8)
  • 1
    Electronic Resource
    Electronic Resource
    Comparison of intestinal mast cell and basophil histamine release in children with food allergic reactions (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 44 (1989), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The in vitro histamine release response of human intestinal mast cells and basophils challenged with anti-IgE, Concanavalin A, ionophore A23187 and food extracts was compared with skin prick test, RAST analysis and open food challenge. It was not possible to perform food challenge in all patients; however, seven children underwent open food challenge and in five the clinical diagnosis of “true” food allergy was confirmed. The intestinal mast cells were pooled from enzymatically dispersed duodenal biopsies obtained by duodenoscopy from 15 selected children suspected of food allergy, and five age-matched controls. In nine of 10 patients classified as “food allergic” intestinal mast cells released histamine to various food extracts in a dose-dependent fashion. From the mast cells of the nine food-allergic patients compared with non-allergics, the anti-IgE mediated mast cell histamine release was increased. Additionally, at 1000 U/ml anti-IgE the mast cell histamine release was increased compared with their corresponding basophils. However, in non-allergic subjects the histamine release of basophils was increased compared with their corresponding mast cells. Histamine release from basophils was positively correlated to the test scores of the RAST analysis, skin prick test, and food challenge. No apparent correlation between tests scores obtained from histamine release of intestinal mast cell and the other tests was demonstrated, except in children with diarrhoea as only symptom. However, the study gives evidence that duodenal mast cells actually are sensitized with specific IgE and thus may play a pathophysiological role in food hypersensitivity. In addition, the study shows that the ability of different stimuli, including food extracts, to trigger basophil histamine release does not correlate with their potency to induce histamine release from mast cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1989.tb04200.x
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  • 2
    Electronic Resource
    Electronic Resource
    A new glass microfibre-based histamine analysis for allergy testing in children (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 42 (1987), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A new microfibre method for allergy testing measuring histamine release from human basophil leukocytes is described. Samples of 50 μl washed blood are challenged with the suspected allergens. Released histamine is bound to microfibres and measured by a spectrofluorometrical method after removal of interfering substances by washing. The microfibre method (HR-MM) was compared to the conventional histamine release assay using the Ficoll-Hypaque gradient method (HR-FH) in 19 allergic children tested with one of three allergens. In addition, a comparison was made between the microfibre method and in vivo provocation tests, i.e. skin prick test (SPT), bronchial provocation test (BPT) and allergen specific serum IgE (RAST). It was found that the same individuals responded with histamine release to the same allergens in both histamine release assays, and the dose-response curves were almost identical. A positive correlation was found between the in vivo and in vitro tests. Thus it is concluded that the new method can provide reproducible, analytically precise (at the nanogram level) histamine release results in pediatric cases where: 1) a positive SPT does not correlate with case history; 2) BPT may be considered too hazardous or inconvenient; 3) confirmation of negative or inconclusive SPT or RAST is needed. In contrast to other histamine release assays it is a convenient diagnostic tool in children since only small amounts of blood are needed and at least 96 tests can be carried out in 21/2 h
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1987.tb02223.x
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  • 3
    Electronic Resource
    Electronic Resource
    Histamine release from dispersed human intestinal mast cells (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 44 (1989), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To study the human intestinal mast cell of children and adults, we combined a sensitive glassfibre-based histamine assay with the enzymatic and mechanical dispersion of surgical specimens or mucosal biopsies. The method yields between 1.2 × 103 to 4.6 × 103 mast cells/mg tissue constituting 1.2% to 5.3% of total cell count. The mast cell yield, however, depends on the intestinal tissue specimen used for dispersion. Aliquots containing 1500 mast cells per sample are sufficient for measuring significant amounts of histamine (± 0.15 ng histamine per sample), thus making it possible, to carry out approximately 75 tests for four mucosal biopsies of 10 mg each. The intestinal mast cell releases histamine in a dose-dependent manner on challenge with anti-IgE (6–600 U/ml), ionophore A23187 (0.25–1.0 μM), and Concanavalin A (0.7–25.0 μg/ml). The histamine release shows interindividual variation with a net histamine release between 0 to 2.5 ng/samples dependent on the secretatogue. In general, it is not necessary to passively sensitize the mast cells to obtain a sufficient histamine release response to anti-IgE challenge, indicating the presence of intact and functional cell-bound IgE. However, it is shown that four of 10 non-atopic intestinal mast cell samples could be passively sensitized with human plasma containing either mite- or grass-specific IgE without stripping off the IgE first. This indicates the presence of free and preserved Fc-receptors on the dispersed mast cells in some subjects. In addition, it is found that the phorbolester TPA increases the histamine release response to A23187 and turns anti-IgE non-responding mast cells into responding mast cells, but TPA alone at 2 to 16 ng/ml has no histamine releasing effect. In patients with anti-IgE responding mast cells no additional effect of TPA is seen. Finally, no substantial differences between mast cells of children and adults are demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1989.tb04199.x
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  • 4
    Electronic Resource
    Electronic Resource
    Passive sensitization of basophil leukocytes from a non-atopic adult by plasma from allergic children (1988)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 43 (1988), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Basophil leukocytes from a non-atopic donor, who responded well to anti-IgE, were depleted of their native membrane-bound IgE by acid treatment and passively sensitized with plasma containing either Phleum pratense-, Dermatophagoides pteronysstnus- or dog dander- specific IgE obtained from 18 allergic children. Histamine release was then performed on the passively sensitized cells and the results were compared with those of bronchial provocation test (BPT), allergen-specific serum IgE (RAST), skin prick test (SPT), and conventional histamine release test (HR). A high coincidence rate was found between BPT, RAST and histamine release after passive sensitization (HR-PS), but compared to HR, it was lower. This could be because several of the patients had non-responding basophils (i.e. no release after challenge with anti-IgE) in the conventional histamine release asssay. The lower rate was not related to a lack of antigen-specific IgE, since after passive sensitization of basophils, anti-IgE and allergen provocation could induce release. It is concluded that plasma from allergic children with non-responding basophil leukocytes contain antigen-specific IgE capable of binding to Fc-receptors on the basophils of a non-atopic donor. In addition it was found that the plasma could change the cell reactivity (maximal histamine release) of the donor cells, since the amount of histamine released varied according to the plasma used for passive sensitization. The lack of histamine release response in some patients could be because their own membrane-bound IgE is unable to induce mediator release or, more likely, activation of one or more of the subcellular steps involved in the release is impaired.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1988.tb02041.x
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  • 5
    Electronic Resource
    Electronic Resource
    Passive sensitization of human intestinal mast cells (1989)
    Springer
    Inflammation research 27 (1989), S. 93-96 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dispersed human intestinal mast cells were used for passive sensitization experiments. Eight biopsies (9.7±1.2 mg/biopsy) of human duodenum were collected from non-atopic children (5) and adults (5). The tissue was dispersed mechanically and enzymatically to yield single cell suspensions. The method produced 2×103 mast cells per mg wet weight of tissue in a purity of 2.8%. Passive sensitization of the mast cells was performed with the patients' own plasma and plasma obtained from atopic donors. The non-atopic mast cells were able to bind the allergen-specific IgE. In addition, passive sensitization with atopic donor-plasma enhanced the cell sensitivity and cell reactivity to anti-IgE challenge, but had no effect on the cellular response to the ionophore A23187. The study shows that the enzymatic dispersion of human intestinal mast cells produces functionally intact mast cells with preserved Fc-receptors which can be passively sensitized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02222208
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  • 6
    Electronic Resource
    Electronic Resource
    Stimulation of histamine synthesis from tumour cells by concanavalin A and A23187 (1987)
    Springer
    Inflammation research 20 (1987), S. 291-294 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the present study the amount of histamine synthesized by two experimental tumour cell lines, the Yoshida ascites sarcoma cells and SEWA cells, was measured after stimulationin vitro with the calcium ionophore A23187 and the plant lectin Concanavalin A (Con A). After 7 hrs of incubation with the two stimulators, histamine could be measured and the amount was still increasing up to 15 hrs of incubation with a maximal net histamine production of approximately 1.0 ng histamine per 106 tumour cells per ml sample. In addition, the tumour promoter 12-0-tetradecanoyl-phorbol-13-acetate (TPA) was found to enhance the synthesis of histamine in the presence of Con A or A23187, except in high concentrations, i.e. 50 ng/ml TPA, where an inhibitory effect was seen. TPA alone could not induced detectable histamine synthesis. In order to measure the histamine, the tumour cells were incubated in glass microfibre-based microtiter plates, which have been shown to bind histamine with high affinity and selectivity. The aim has been to develop a functionalin vitro tumour assay which can detect histamine from tumour cells and which can be used to measure pharmacological interaction of the tumour cell function as well as histamine production from different tumour cell types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02074694
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  • 7
    Electronic Resource
    Electronic Resource
    Impaired basophil histamine release from allergic patients (1987)
    Springer
    Inflammation research 20 (1987), S. 303-306 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A few patients (6–7%) with a verified type I allergic reaction do not respond with histamine release after challenge of their basophils with specific antigen (non-responding basophils from allergic patients). Sera from these non-responding patients were used for passive sensitization of responding cells from healthy controls. When these sensitized cells were challenged with specific antigen, histamine release was observed indicating that the non-responding allergic patients have circulating antigen-specific IgE capable of binding to Fc-receptors on the basophils. These findings suggest the possibility that non-responding basophils have impaired cell functions. We therefore examined the influence of enhanced IgE receptor stimulation on histamine release in non-responding basophils. This was made by stimulating protein kinase C activity by a phorbol ester (phorbol 12-myristate 13-acetate). When the non-responding cells were incubated with the phorbol ester and challenged with either anti-IgE or specific antigen, the cells released histamine. These findings support the hypothesis that the unresponsiveness of basophils in some allergic patients is associated with impaired IgE receptor complex activation or subcellular functioning and not with a lack of cell-bound IgE.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02074697
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  • 8
    Electronic Resource
    Electronic Resource
    Inhibition of basophil histamine release by methotrexate (1988)
    Springer
    Inflammation research 23 (1988), S. 173-176 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Basophil leukocytes in whole blood from 4 healthy donors, 4 atopic patients and 10 female patients operated for breast-cancer were preincubated from 1 to 20 hrs alone or in the presence of methotrexate (MTX) or MTX and folinic acid. After preincubation, the basophil leukocytes were challenged with anti-IgE, allergens or the calcium ionophore A23187 in the presence of 25 ng/ml TPA (12-o-tetradecanoyl-phorbol-13-acetate). A 9-hr preincubation with MTX produced significant inhibition of histamine release (〉20%) at 500–50 μg/ml. This effect increased up to 20 hrs of incubation, displaying maximal activity (100% inhibition) at 500μg/ml, but even submicrogram concentrations (0.5μg/ml) produced significant inhibition. The addition of folinic acid did not alter the inhibition. It is concluded that MTX with or without the addition of folinic acid is a potent inhibitor of histamine release induced by anti-IgE, allergens, and A23187 combined with TPA. Like glucocorticoids the mechanism of action of MTX may be linked to arachidonated metabolism, but may interrupt earlier steps in prostaglandin synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02142532
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