Histamine is synthesized via histidine decarboxylase (HDC) in wide types of immune cells and is involved in abundant physiologic and pathologic processes. Histamine is a mediator released during inflammatory reactions, such as food allergy. Food allergy is immunological reactions to 'fight off' specific allergens within food in susceptible individuals. The aim of this study is investigation of ...

BACKGROUND AND AIMS Evidence suggests that the intestinal actions of Clostridium difficile toxin A-stimulation of secretion and motility, and an acute inflammatory response-have a neurally mediated component. METHODS Direct intracellular electrophysiological recording of electrical and synaptic behaviour in enteric neurones was performed in the submucous plexus of guinea pig small intestine d...

Anaphylaxis, the most serious and life-threatening allergic reaction, produces the release of inflammatory mediators by mast cells and basophils. Regulator of calcineurin 1 (Rcan1) is a negative regulator of mast-cell degranulation. The action of mediators leads to vasodilation and an increase in vascular permeability, causing great loss of intravascular volume in a short time. Nevertheless, th...

The role of cyclic AMP in histamine release induced by human leukocyte lysates was investigated. Leukocytes were incubated with leukocyte lysates prepared by ultrasonic disruption, and histamine was determined fluorimetrically. Several cyclic AMP-active agents had a marked inhibitory effect on histamine release. Theophylline and isoproterenol produced 50% inhibition at concentrations of less th...

The Cbl family of proteins negatively regulate signaling from tyrosine kinase-coupled receptors. Among the three members of this family, only c-Cbl and Cbl-b are expressed in hemopoietic cells. To examine the role of c-Cbl and Cbl-b in Fc epsilon RI signaling, mast cell cultures from wild-type, c-Cbl(-/-), and Cbl-b(-/-) mice were generated. Cell growth rates and cell surface expression of Fc e...

Aggregation of the high affinity receptor for immunoglobulin E (Fc epsilon RI) on mast cells results in rapid tyrosine phosphorylation and activation of Syk, a cytoplasmic protein tyrosine kinase. To examine the role of Syk in the Fc epsilon RI signaling pathway, we identified a variant of RBL-2H3 cells that has no detectable Syk by immunoblotting and by in vitro kinase reactions. In these Syk-...

Compounds that increase tissue concentrations of cyclic AMP inhibit the release of histamine from sensitized tissues when they are challenged with antigen. It has been proposed that the anti-asthmatic agent disodium cromoglycate exerts its anti-allergic properties by inhibiting cyclic AMP phosphodiesterase. This hypothesis was based on experiments where it was shown that the inhibition of antig...

The survival oriented adaptation of evolved biosystems to variations in their environment is a selective optimization process. Recognizing the optimised end product and its functionality is the classical arena of bionic engineering. In a primordial world, however, the molecular organization and functions of prebiotic systems were solely defined by formative processes in their physical and chemi...

We reported previously that stimulation of RBL-2H3 cells through the high-affinity IgE receptor resulted in tyrosine phosphorylation of a 72-kDa protein (pp72) that was coupled to signal transduction. In the present study, although pp72 tyrosine phosphorylation was induced only by antigen triggering, stimulation of RBL-2H3 cells by either antigen or the calcium-ionophore A23187 led to increased...

An immunotherapeutic vaccine for allergy was produced by designing IgE-based synthetic peptide immunogens and selecting them for functional immunogenicity. The vaccine targets the binding site on IgE for the high affinity receptor Fc epsilon RI, by active immunization. The peptide target site on IgE heavy chain was selected from among the amino acid sequences for the C epsilon 2, C epsilon 3, a...