Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IgE is a homocytotropic antibody which binds to the surface of the mast cell. Antigen with affinity for IgE triggers conformational change at the cell surface, resulting in the release of chemical mediators from the mast cell granules. The mediators histamine, slow reacting substance of anaphylaxis and eosinophil chemotactic factor cause smooth muscle contraction, increased capillary permeability, eosinophil attraction and increased glandular secretions. The release of mediators from the mast cell granules is controlled by intracellular levels of cyclic nucleotides. In particular, elevated cyclic AMP inhibits mediator release. Adrenergic, cholinergic and prostaglandin receptors all influence mediator release. The characteristic immunopathology of immediate hypersensitivity reactions is a result of local or systemic mediator release. Such reactions include anaphylaxis, asthma, allergic rhinitis, urticaria and angioedema. Similar immunopathology may sometimes result from mechanisms not involving IgE or histamine mediators. Routine investigation of patients with immediate hypersensitivity should include eosinophil counts and IgE levels in blood and secretions, and immediate hypersensitivity skin tests. RAST testing is not routine. Therapeutic principles of these reactions include restoration of inhibitory levels of cyclic nucleotides, antagonism of mediator effects and immunological manipulation of the IgE mediated allergic reaction.
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PMID:The immunological basis of immediate hypersensitivity. 8 47

Sixteen patients with allergic rhinitis were recruited into a double-blind crossover protocol studying the immediate effect of nedocromil sodium (NS) on the pattern of nasal symptoms and secretions after allergen challenge. After pretreatment with placebo or NS, allergen challenge resulted in pruritus, rhinorrhea, nasal congestion, and/or sneezing within 10 minutes in 12 of 16 subjects. Prostaglandin D2 (PGD2), a marker of mast cell degranulation, increased proportionately with symptom scores, remaining above the 95% confidence interval for 120 minutes after both pretreatments. No difference in PGD2 between the NS-treatment and placebo-treatment days was observed. Protein markers extravasated through the vasculature (albumin and IgG) or secreted by mucosal glands (lactoferrin) were assayed. Total protein, albumin, IgG, and lactoferrin all remained greater than 95% confidence interval for 100 minutes after allergen challenge in the placebo-pretreated group and 120 minutes in the NS-pretreated group. Although there appeared to be a trend for lower secretion of PGD2, albumin, and IgG in the NS-treated group, the overall differences did not achieve statistical significance. This protocol revealed that two topical 130 microliter doses of a 1% solution of NS failed to significantly reduce allergen-induced symptoms, PGD2 generation, or secretion of albumin, IgG, or lactoferrin when NS was compared with placebo. The anti-inflammatory and mast cell-stabilizing effects of NS may require more prolonged pretreatment before provocation to be effective.
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PMID:Effects of nedocromil sodium on allergen-induced rhinitis in humans. 131 Oct 8

To study the effect of azelastine on the immediate reaction to nasal allergen challenge, we performed a double blind, placebo-controlled cross-over clinical trial. Thirteen subjects with seasonal allergic rhinitis underwent nasal challenge with antigen 4 hr after a single oral 2 mg dose of azelastine. The response was monitored by counting the number of sneezes and by measuring the levels of histamine, prostaglandin D2, immunoreactive sulphidopeptide leukotrienes, kinis and TAME-esterase activity in recovered nasal lavages. After a single dose of azelastine, there was a significant reduction in sneezing (10 vs 2, P = 0.01) and in the median levels of recovered TAME-esterase activity (63.1 vs 17.5 c.p.m. x 10(-3), P = 0.01), immunoreactive sulphidopeptide leukotrienes (7.5 vs 2.1 ng/ml, P = 0.03) and kinins (1370 vs 251 pg/ml, P = 0.03), with no significant reduction in the median levels of histamine (3.7 vs 1.2 ng/ml, P = 0.2) and prostaglandin D2 (70 vs 70 pg/ml, P = 0.2) compared to placebo (numbers represent total increase over diluent challenge). These results suggest that azelastine does not inhibit mast cell activation but affects the consequences of released histamine, namely sneezing, increased vascular permeability and the generation of kinins. The results further suggest that other cells, in addition to mast cells, might be responsible for the generation of leukotrienes during the early allergic response, and that azelastine reduces their ability to generate this mediator or that inhibition of leukotriene release from mast cells occurs at lower drug concentrations.
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PMID:The effect of azelastine on the early allergic response. 134 59

Although histamine is the principal mediator of the immediate allergic reaction, other inflammatory mediators as well as neuropeptides also contribute to rhinorrhea and nasal congestion. Within minutes of exposure to allergen, mast cells produce histamine, leukotriene C4, and prostaglandin D2. A concomitant increase occurs in neuropeptides and bradykinin. In vitro mast cell activation also leads to the release of tumor necrosis factor--alpha, several interleukins, and granulocyte-macrophage colony--stimulating factor. Because all these various mediators and neuropeptides may play a role in producing rhinorrhea and congestion, antihistamines alone cannot control all of the symptoms of allergic rhinitis. However, the combination of antihistamines with topical corticosteroids can inhibit the generation, release, and activity of most if not all of the mediators potentially involved in the allergic response.
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PMID:Mediators of allergic rhinitis. 140 52

Allergic rhinitis caused by pollen of Japanese cedar (Cryptomeria japonica) is found in Japan. These pollens, when inhaled into the nasal cavity, contact the nasal mucus membrane, and the allergens separate from the pollens, and pass through the nasal mucosa to interact with the mast cell-bound IgE. Patients with allergic rhinitis produce a great volume of nasal secretion from the mucosa. The morphological transformation of the cedar pollens when mixed with nasal secretion was studied. Nasal secretion was collected from two patients with allergic rhinitis. Cedar pollen gathered from a Japanese cedar tree was mixed with distilled water, and the cedar pollen suspension was mixed with a drop of nasal secretion on a slide glass at the room temperature (23 degrees C), and examined by phase-contrast microscopy. Of the pollen 20.6% were ruptured after 3 min, and 52.9% after 10 min, 84.9% after 40 min, and 81.3% after 60 min respectively. Further changes in shape of the ruptured pollens were observed with continued incubation. A hole opened in the cytoplasmic membrane through which the nucleus escaped, and crinkling of the residual cytoplasmic membrane was observed. The escaped nucleus separated into many small granules. In order to determine possible causes of the pollen rupture in nasal secretion, the relationship between pH of the nasal secretion and rupture rate was examined. The pH of the nasal secretion from two patients was 8.95 and 9.15 respectively. Salt solutions of 0.1 M NaCl, (NH4) 2SO4, NaNO3, CaCl2, Na2SO4, KCl, MgSO4, had pH range from 5.13 to 6.40.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The rupture of cedar pollens in nasal secretions]. 150 28

The atopic diseases--allergic rhinitis, asthma, and atopic dermatitis--are chronic inflammatory diseases characterized by an exacerbating and remitting course and can only rarely be associated causally with allergen exposure. The challenge to ascribe an allergic basis to these diseases is derived from the apparent inability to reconcile these chronic inflammatory features with a process thought to be initiated by the rapid release of mediators after the interaction of allergen with IgE-coated mast cells. The traditional understanding has been that mast cell activation results in the release of a series of preformed and rapidly synthesized substances that mediate the immediate onset of vasodilatation, vascular leakage, smooth muscle contraction, and irritant nerve receptor stimulation. These mediators, however, are rapidly degraded and are not thought to be associated with a significant inflammatory component. Recent studies, however, have established that the interaction of allergen with the immune system is, in fact, far more complex (Fig. 4). In addition to mast cell activation, allergen can interact with and activate T-lymphocytes and mononuclear phagocytic cells, leading to the secretion of cytokines and other inflammatory substances. Furthermore, the interaction of allergen with the mast cell may be far more complex, with the potential to stimulate the delayed release of newly synthesized cytokines. The interaction of allergen with the immune system also promotes the secondary release of inflammatory neuropeptides. Thus, the known spectrum of mediators released after allergen exposure has vastly been expanded. These include numerous still uncharacterized chemotactic and activating peptides; eicosanoids such as 5-HETE, 12-HETE, and leukotriene B4; platelet-activating factor; several proteases; neuropeptides and, most importantly, the cytokines. These mediators recruit and activate neutrophils, monocytes, basophils, and eosinophils, attract additional lymphocytes and mononuclear phagocytic cells, and induce mast cell proliferation with further mast cell degranulation. A vicious cycle subsequently develops, with further inflammation and tissue destruction. Thus, the interaction of allergen with the immune system has become a complex cascade capable of producing the chronic inflammatory changes characteristic of allergic diseases.
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PMID:Inflammation and the allergic response. 161 34

We evaluated basophil releasability in two groups of allergic patients with positive skin tests to Dermatophagoides pteronyssinus major allergen (Der p l) (29 adults with bronchial asthma and 17 with allergic rhinitis) and in 31 age-matched normal donors. Both basophil reactivity (maximal percent histamine release) and basophil sensitivity (the concentration that causes 50% of maximal percent histamine release: HC50) to Der p l in patients with asthma were similar to those in patients with allergic rhinitis. On the contrary, basophil reactivity to anti-IgE was significantly higher in patients with asthma (58.0 +/- 3.6%) than in patients with allergic rhinitis (46.3 +/- 5.2%; p less than 0.05). Both groups of patients showed an increased releasability compared to control subjects (27.3 +/- 4.6%; p less than 0.001), whereas there were no significant differences in basophil sensitivity to anti-IgE among the three groups of donors. Differences were also found with respect to basophil reactivity and sensitivity to f-met peptide, whereas no differences appeared when basophils from the three groups of donors were challenged with the Ca2+ ionophore A23187. There was a significant correlation between basophil reactivity and sensitivity to Der p l and to anti-IgE in both asthmatic and allergic rhinitis patients. A significant correlation was found between basophil reactivity and sensitivity to anti-IgE and serum IgE level only in patients with bronchial asthma, whereas no correlations were found in patients with allergic rhinitis. There was no correlation between in vivo mast cell releasability and in vitro basophil releasability in response to Der p l in either group of allergic patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human basophil releasability. VI. Changes in basophil releasability in patients with allergic rhinitis or bronchial asthma. 170 Jun 53

Food allergy (FA) is a very important problem affecting numbers of infants and children with protean manifestations which are frequent challenges to the pediatrician and other specialists working with children. Adverse reactions to food are very complex, frequently mediated bu IgE mechanisms, and often by other mechanisms. To make the correct diagnosis and to arrive at a proper therapeutic approach requires all the skill a physician can gather. Only an extensive knowledge of the various mechanisms and pharmacologic agents that can be used to prevent or treat these adverse reactions will allow the physician to approach the problem scientifically and come to a reasonable solution for the patient. The role of dietary factors in atopic dermatitis (AD) has long been a subject of controversies. However, it has been shown that FA plays a role in some children with AD. Therefore, the management of this multifaceted disorder is a challenge for pediatricians, dermatologists, and allergists. SCG, which is the salt of a bis-chromone carboxylic acid, has been shown to be of proven efficacy in the prophylaxis of bronchial asthma, allergic rhinitis, and of other disorders associated with mast cell degranulation. The drug has different modes of action, such as inhibition of rat passive cutaneous anaphylaxis, and the antigen-induced histamine release from passively sensitized peritoneal cells. Recently, clinical studies indicated that SCG has a direct effect on inflammatory cells, inhibiting either various leukocyte functions (membrane receptor expression, cytotoxic capacity), or "in vitro" activation of human neutrophils, eosinophils and monocytes. Although SCG has been widely used for the management of respiratory allergy, conflicting results of FA treatment have been reported by several authors. We have reviewed 18 papers on the use of SCG in the management of children with FA, which included 341 children aged 0.5-15 years. In this paper we discuss 12 studies reporting 281 children affected with AD.
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PMID:Food allergy in children: diagnosis and treatment with sodium cromoglycate. 170 97

Allergic rhinitis is characterized by a profuse rhinorrhea in addition to paroxysms of sneezing, nasal congestion, and pruritus. To define better the sources of nasal secretion produced during rhinitis, nasal allergen challenges were performed on nine atopic subjects with seasonal rhinitis. A single dose of allergen was sprayed into one side of the nose, and nasal lavages were collected bilaterally for 7 hours. Nasal lavages were assayed for protein (total protein, albumin, lactoferrin, and lysozyme) and mediator (histamine and prostaglandin D2) content. Protein concentrations increased and remained elevated above baseline levels in both ipsilateral and contralateral secretions for up to 3 hours after allergen challenge. The proportion of albumin relative to total protein (the albumin percent) increased on the ipsilateral side, whereas the relative proportions of lactoferrin and lysozyme (the lactoferrin percent and lysozyme percent) increased on the contralateral side. Prostaglandin D2, but not histamine, increased selectively on the ipsilateral side. These data suggest that the ipsilateral protein secretory response is due to allergen-induced mast cell mediator release causing increased vascular permeability, whereas the contralateral protein secretory response is primarily a reflex-induced glandular secretion.
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PMID:The pathophysiology of rhinitis. V. Sources of protein in allergen-induced nasal secretions. 171 3

The advantages of topical (as opposed to systemic) therapy for allergic rhinitis include the avoidance of undesirable systemic effects and the concentration of therapeutic effect on the target organ. Successful topical therapy requires establishment of a proper diagnosis, followed by effective delivery of the medication to the nasal mucosa. In addition to currently available preparations such as cromolyn sodium and various corticosteroids, several other topical nasal preparations for the treatment of allergic rhinitis are under investigation. These include antihistamines (eg, levocabastine), anti-inflammatory/mast cell stabilizing drugs (eg, nedocromil), new corticosteroids (eg, triamcinolone, budesonide, fluocortin, fluticasone), anticholinergics (eg, ipratropium), and miscellaneous agents (eg, HEPP [IgE pentapeptide]).
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PMID:Topical pharmacotherapy for allergic rhinitis: new agents. 173 80


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