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Biomedical subjects

M Philippart

Publications and source records attributed to M Philippart.

At least 55 records · Page 3Linked to original sources

Sphingomyelinases in human tissues. II. Absence of a specific enzyme from liver and brain of Niemann-Pick disease, type C.

Sphingomyelinase was obtained in excellent yield from liver and brain by homogenization with 0.05 M citrate-phosphate buffer, pH 4.5, containing 0.25% Triton-X-100 (v/v) followed by dialysis of the supernatant fluids against 1% glycine. Total recovery of enzyme was slightly less with tissue from Niemann-Pick disease compared with control tissue. Isoelectric focusing of liver and brain extracts was successfully used to resolve several species of sphingomyelinase. Three (I-III) of the five species were partially characterized. Enzyme I (pI 4.6) had a pH optimum of 4.8-5.0 in acetate buffer and a Km value of 0.026 mM. Both sphingomyelinases I and II were the major enzymes, whereas III, IV, and V were found at lower levels. Of the two major species in normal liver and brain (I and II), species I alone persisted in liver from the two cases of type C, while species III, IV, and V were present. In brain, only species II was decreased but the resolution of the brain enzymes was less satisfactory.

Brain↗

Cultured skin fibroblasts in storage disorders. An analysis of ultrastructural features.

Electron microscopic studies were performed on cultured fibroblasts from patients with metachromatic leukodystrophy, Fabry's, Gaucher's, Niemann-Pick's (Type A and C), Sanfilippo's (Type A and B) disease, chondroitin-4-sulfate mucopolysaccharidosis, lipofuscinosis (Spielmeyer-Vogt's disease) and ceroid-lipofuscinosis (Batten's disease with curvilinear bodies). Specific cytoplasmic inclusions with a limiting membrane were identified in Fabry's disease, Niemann-Pick syndrome, chondroitin-4-sulfate mucopolysaccharidosis and Sanfilippo's Type B disease. In Fabry's disease, the lipid inclusions tended to form stacks of parallel and concentric membranes. In Niemann-Pick syndrome, the lipid inclusions were made of wavy, loosely packed membranes. In chondroitin-4-sulfate mucopolysaccharidosis and Sanfilippo B, the lysosomes were enlarged and contained a reticular matrix with little electron-dense material. No specific ultrastructural changes were observed in Gaucher's, Sanfilippo's (Type A) disease, metachromatic leukodystrophy (sulfatidosis) and Batten's disease.

Biopsy↗