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...

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...

BACKGROUND Juvenile Tay-Sachs disease is rarer than other forms of Tay-Sachs disease and is usually seen in children between the age of 2 and 10 years. Pyrimethamine as a pharmacological chaperone was used to increase β-hexosaminidase A activity in this patient. PATIENT We describe a patient with Tay-Sachs disease from the Indian population, a juvenile case who presented with developmental re...

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...

Exhaled nitric oxide (eNO) is decreased by cigarette smoking. The hypothesis that oxides of nitrogen (NOX) in cigarette smoke solution (CSS) may exert a negative feedback mechanism upon NO release from epithelial (AEC, A549, and NHTBE) and basophilic cells (RBL-2H3) was tested in vitro. CSS inhibited both NO production and degranulation (measured as release of beta-hexosaminidase) in a dose-dep...

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...

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...

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-...

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 -/-...

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...