ABSTRACT
BACKGROUND: Gaucher's disease (GD) is a disorder caused by the deficiency of lysosomal beta-glucosidase, an enzyme that participates in the degradation of glycosphingolipids. Deficiency of this enzyme results in the accumulation of glucocerebrosides in macrophage lysosomes. No studies comparing the biochemical and kinetic behavior of this enzyme in leukocytes and fibroblasts from normal individuals and patients with Gaucher's disease are available. METHODS: We compared the activities of beta-glu and chitotriosidase between normal subjects and Gaucher disease patients, and characterized the behavior of beta-glu in terms of pH optimum, heat stability, Km and Vmax. RESULTS: The results showed a different behavior of the enzyme in the groups analyzed. CONCLUSIONS: This finding might be useful in cases in which the measurement of enzyme activity alone is not reliable for the establishment of the diagnosis of Gaucher's disease.
Subject(s)
Gaucher Disease/enzymology , beta-Glucosidase/metabolism , Case-Control Studies , Cells, Cultured , Enzyme Stability , Fibroblasts/enzymology , Hexosaminidases/metabolism , Homozygote , Hot Temperature , Humans , Hydrogen-Ion Concentration , Kinetics , Leukocytes/enzymologyABSTRACT
BACKGROUND: Organic acidurias or organic acidemias are inherited metabolic disorders in which organic acids (carboxylic acids) accumulate in tissues and physiologic fluids of affected individuals. They are considered the most frequent metabolic disorders among severely ill children. Patients frequently present acute symptoms in early life. Metabolic acidosis and neurologic symptoms are the most common signs. METHODS: Urine specimens obtained from 1,926 children from January 1994 to July 2001 were used in analyses. Venous blood specimens were also collected from some patients. Samples were initially submitted to screening tests for detection of inborn errors of metabolism. Identification and semi-quantitation of organic acids in urine were performed by gas chromatography or gas chromatography coupled to mass spectrometry using capillary column (DB-5) and flame ionization detection. RESULTS: Ninety three (4.8%) cases of organic acidemias were diagnosed among 1,926 patients investigated from January 1994 to July 2001. Prompt therapy was instituted after diagnosis in a considerable number of patients and resulted in rapid improvement in their symptomatology, distinct from our previous cases diagnosed abroad where patients representing index cases died before any measure could be taken. CONCLUSIONS: Results demonstrate the importance of diagnosing organic acidurias in loco in developing countries despite implied extra costs.
