Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042109 (urticaria)
 6,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A skin eruption simulating 'papular urticaria' was observed in 6% of 500 patients with cancer. Twenty seven of them had carcinoma affecting different organs, while 3 had lymphoma. Direct observation revealed that the skin lesions were the result of bites by the mosqmtoes. There was direct correlation between mosquito bite reaction and the response to iadermal tests with mosquito antigen , (MSA). The leucocytee migration inhibition test usmg MSA revealed the existence of cell mediated immunity to MSA in these patients with 'papular urticaria'. Specific treatment for malignancy apparently influenced the pattern of reaction to ID test as well as to mosquito bites. The histopathologic studies revealed non-- specific changes in the delayed papules after mosquito bites. The MAS test papules closely simulated morphologically and histologically, te delayed papules of mospuito bites. None of the 12 attendants of cancer patients who were exposed to similar environment as that of cancer patient, while in the ward or at home, developed similar reaction either to MSA or to direct mosquito bite. None of the healthy volunteers or patients with diseases other than cancer, developed similar reaction either to MSA or to direct bites by mosquities. The role of irradiation and malignancy in the abolition of 'Suppressor T cell" activity in the aetiology of these skin eruptions is discussed.
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PMID:Abnormal Cutaneous Response to Mosquito Bites in Cancer Patients. 2819 16

Mast cells are tissue-resident innate immune cells known for their prominent role in mediating allergic reactions. MAS-related G-protein coupled receptor-X2 (MRGPRX2) is a promiscuous G-protein coupled receptor (GPCR) expressed on mast cells that is activated by several ligands that share cationic and amphipathic properties. Interestingly, MRGPRX2 ligands include certain FDA-approved drugs, antimicrobial peptides, and neuropeptides. Consequently, this receptor has been implicated in causing mast cell-dependent pseudo-allergic reactions to these drugs and chronic inflammation associated with asthma, urticaria and rosacea in humans. In the current study we examined the role of osthole, a natural plant coumarin, in regulating mast cell responses when activated by the MRGPRX2 ligands, including compound 48/80, the neuropeptide substance P, and the cathelicidin LL-37. We demonstrate that osthole attenuates both the early (Ca2+ mobilization and degranulation) and delayed events (chemokine/cytokine production) of mast cell activation via MRGPRX2 in vitro. Osthole also inhibits MrgprB2- (mouse ortholog of human MRGPRX2) dependent inflammation in in vivo mouse models of pseudo-allergy. Molecular docking analysis suggests that osthole does not compete with the MRGPRX2 ligands for interaction with the receptor, but rather regulates MRGPRX2 activation via allosteric modifications. Furthermore, flow cytometry and confocal microscopy experiments reveal that osthole reduces both surface and intracellular expression levels of MRGPRX2 in mast cells. Collectively, our data demonstrate that osthole inhibits MRGPRX2/MrgprB2-induced mast cell responses and provides a rationale for the use of this natural compound as a safer alternative treatment for pseudo-allergic reactions in humans.
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PMID:Osthole, a Natural Plant Derivative Inhibits MRGPRX2 Induced Mast Cell Responses. 3239 Oct 14