The pathogenic mycobacteria that cause tuberculosis (TB) and TB-like diseases in humans and animals elude sterilizing immunity by residing within an intracellular niche in host macrophages, where they are protected from microbicidal attack. Recent studies have emphasized microbial mechanisms for evasion of host defense; less is known about mycobactericidal mechanisms that remain intact during i...

Fluorigenic substrates prepared from 4-methylumbelliferone provide a simple, convenient method for detecting and assaying group-specific hydrolase activity in small quantities of whole mycobacteria. Physico-chemical properties of the enzymes such as pH dependence and heat stability may also be studied. A technique is described for studying glycosidase, hexosaminidase, acid phosphatase, and acyl...

The hydrolysis in lysosomes of GM2 ganglioside to GM3 ganglioside requires the correct synthesis, intracellular assembly and transport of three separate gene products; i.e., the alpha and beta subunits of heterodimeric beta-hexosaminidase A, E.C. # 3.2.1.52 (encoded by the HEXA and HEXB genes, respectively), and the GM2-activator protein (GM2AP, encoded by the GM2A gene). Mutations in any one o...

Background: The concentration and specific activity of N-acetyl-b-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-b-hexosaminida...

Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the α-subunit of lysosomal β-hexosaminidase A, which converts G(M2) to G(M3) ganglioside. Hexa(-/-) mice, depleted of β-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise G(M2) ganglioside via a lysosomal sialidase into glycolipid G(A2), which is further processed by β-h...

Tay-Sachs disease is a prototypic neurodegenerative disease. Lysosomal storage of GM2 ganglioside in Tay-Sachs and the related disorder, Sandhoff disease, is caused by deficiency of beta-hexosaminidase A, a heterodimeric protein. Tay-Sachs-related diseases (GM2 gangliosidoses) are incurable, but gene therapy has the potential for widespread correction of the underlying lysosomal defect by means...

The human leukemia cell lines HL-60, KG-1, KLM-2, ML-3, THP-1, and U-937 were treated with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). TPA partially or completely inhibited the proliferative activity of the cell cultures. The number of cells with the ability to reduce nitroblue tetrazolium increased in the TPA-treated cell lines HL-60, ML-3, THP-1, and U-937, whereas the cell ...

We studied the effects of representative endocrine-disrupting chemicals on beta-hexosaminidase release from mast cells and their putative neurosteroid receptor involvement. Some endocrine-disrupting chemicals, such as amitrol, benzophenon, bisphenol A, pentachlorophenol, and tetrabromophenol A did not cause hexosaminidase release from RBL-2H3 cells, but they blocked the release by dehydroepiand...

colon polyps in familial adenomatosis polyposis (FAP) patients Department of Pathology, Center for Environmental Medicine, Medical (14–17). Hence, in both clinical and laboratory investigations, College of Ohio, 3000 Arlington Avenue, Toledo, OH 43614, USA NSAIDs appear to prevent the progression of precancerous 1To whom correspondence should be addressed lesions in the colon. Regression of pre...