Biological functions of mast cells include a functional role in innate immunity against parasitic infections. Here, we demonstrated that mast cells could also play a role in the anti-microbial defenses regulation and might participate as a parasite reservoir. We observed that Toxoplasma gondii infected massively in vitro mouse bone marrow derived mast cells (BMMC), a mucosal mast cell (MMC) phe...

An assay for measuring hexosaminidase A in serum and leucocytes is described in which a centrifugal analyser is used for automation of the enzyme assays after manual heat inactivation. The assay was used in a screening programme to identify heterozygotes for Tay-Sachs disease in Ashkenazi Jewish subjects in the UK. The first results from this programme indicate a carrier frequency of 1 in 27. A...

Hexosaminidase C was separated from human brain supernatant by immunoadsorption of the A and B forms on to a column of immobilized antibody followed by preparative starch-block electrophoresis. There were some differences in the properties of hexosaminidase C preparations after each of these stages, shown by comparison of their heat-inactivation characteristics and filtration through Bio-Gel P-...

Using rat mast cells permeabilized with streptolysin O we show that release of arachidonate generally occurs under similar but not identical conditions to those that cause exocytosis of beta-N-acetylglucosaminidase (hexosaminidase). Thus, hexosaminidase secretion and arachidonate release both require provision of Ca2+ together with a guanine nucleotide but exocytosis occurs at lower concentrati...

fcεri, the high affinity receptor for ige plays a critical role in triggering the allergic reactions. it is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and ige complexes. fcεri on the mast cells consists of three subunits; α chain directly binds ige, β chain and dimmer of γ chains together mediate intracellular signali...

BACKGROUND The concentration and specific activity of N-acetyl-β-hexosaminidase (HEX) in palatine tonsils with chronic tonsillitis and tonsillar hypertrophy give insight in tonsillar tissue remodeling and constitute a potential marker for diagnosis and treatment of chronic tonsillitis and tonsillar hypertrophy. AIM Determining the concentration and specific activity of N-acetyl-β-hexosaminida...

Recent genetic evidence suggests that aberrant glycosphingolipid metabolism plays an important role in several neuromuscular diseases including hereditary spastic paraplegia, hereditary sensory neuropathy type 1, and non-5q spinal muscular atrophy. Here, we investigated whether altered glycosphingolipid metabolism is a modulator of disease course in amyotrophic lateral sclerosis (ALS). Levels o...

We have generated mouse models of human Tay-Sachs and Sandhoff diseases by targeted disruption of the Hexa (alpha subunit) or Hexb (beta subunit) genes, respectively, encoding lysosomal beta-hexosaminidase A (structure, alpha) and B (structure, beta beta). Both mutant mice accumulate GM2 ganglioside in brain, much more so in Hexb -/- mice, and the latter also accumulate glycolipid GA2. Hexa -/-...

We have failed to detect the presence of mannose-6-phosphate in the oligosaccharide moiety of glycoproteins from pea (Pisum sativum L. cv Burpeeana) cotyledons using an assay system sensitive to 10 picomoles of mannose-6-phosphate. We were also unable to demonstrate any retention of glycosidase activity from pea seedlings and pea cotyledons on Sepharose-coupled phosphomannosyl receptor proteins...