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Nitric oxide (NO) is synthesised by many cell types involved in immunity and inflammation. The principal enzyme involved is the inducible type-2 isoform of nitric oxide synthase (NOS-2), which produces high-level sustained NO synthesis. NO is important as a toxic defense molecule against infectious organisms. It also regulates the functional activity,(More)
The surface specimen technique was used to study both spiral organs of 28 normal guinea pigs of four age groups: less than 24 hours, 6 weeks, 3 months and 1 year. Damaged hair cells were recorded for the whole of each spiral organ on cochleograms. The mean percentage number of outer hair cells damaged per age group was found to increase as a power function(More)
The immunogenicity of captopril (CP), conjugated to heterologous proteins, was investigated in male New Zealand White rabbits by monthly injections of CP-protein conjugates in Freund's Complete Adjuvant. Anti-CP antibody activity was readily detected by immunodiffusion in sera of rabbits immunized with the amide-linked CP-HSA (23:1) conjugate. Hapten(More)
IFN-gamma regulates various aspects of rodent peritoneal mast cell function, including mediator release, cell growth, TNF-alpha-mediated cytotoxicity, and MHC class II expression. We investigated whether the suppressive action of IFN-gamma on IgE/Ag-mediated degranulation of mast cells is mediated via synthesis of nitric oxide. Incubation of mouse(More)
Stem cell factor (SCF) is potent activator of degranulation of rat peritoneal mast cells in vitro and may promote mast cell activation under certain circumstances in vivo. In this study we report that the anti-inflammatory glucocorticoid dexamethasone (DEX) and the immunosuppressive cyclosporin A (CsA) are both effective inhibitors of SCF-induced(More)
We examined whether three cytokines that promote mouse mast cell development, the c-kit ligand stem cell factor (SCF), IL-3, or IL-4, also can directly stimulate or modulate mouse peritoneal mast cell (PMC) mediator release. Challenge of purified PMC with rat rSCF164 at 20 to 100 ng/ml for 30 min induced a modest release of serotonin (5-HT), whereas IL-3 or(More)
Beta-lactam antibiotics are the class of drug most frequently associated with IgE-mediated allergy but the mechanisms underlying this response are poorly understood. IFN-gamma is a key cytokine in immunity with regulatory actions on monocytes, NK cells, epithelial cells, and T and B lymphocytes. IFN-gamma promotes Th1 responses and inhibits Th2- and(More)
We report that mast cells can bind and present IFN-gamma in a functionally active form to macrophages. Flow-cytometric analysis revealed that biotinylated IFN-gamma bound equally well to purified peritoneal mast cells from both IFN-gammaR knockout and wild-type mice, indicating a non-IFN-gammaR binding site. Purified peritoneal mast cells, loaded with(More)
We report that cultured rat peritoneal cells spontaneously synthesize nitric oxide and this is associated with active suppression of mast cell secretory function. Addition of interleukin-4 (IL-4) or the nitric oxide synthase inhibitor N-monomethyl-l-arginine to peritoneal cells inhibited nitric oxide synthesis and enhanced anti-IgE-mediated mast cell(More)