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Biomedical subjects

A D Patrick

Publications and source records attributed to A D Patrick.

At least 55 records · Page 3Linked to original sources
PubMed1976

Prenatal diagnosis of Wolman's disease.

Amniocentesis was performed in the 15th week of a pregnancy at risk for Wolman's disease. The cultured amniotic fluid cells were found to have a severe deficiency of acid esterase activity consistent with homozygosity of the fetus. The pregnancy was terminated in the 19th week and the prenatal diagnosis confirmed by enzymic and chemical evaluation of the fetal tissues.

Amniocentesis↗
PubMed1975

I-cell disease (mucolipidosis II): resolution of N-acetyl-beta-D-glucosaminidase and alpha-L-fucosidase components by DEAE-cellulose chromatography.

1. In a patient with I-cell disease the activities of several acid hydrolases were elevated inplasma and reduced in cultured fibroblasts when compared with normal values. Normal activities for the enzymes were found in leucocytes. These findings agree with reports on other cases. 2. N-Acetyl-beta-D-glucosaminidase was resolved into its component forms by chromatography on microcolumns of DEAE-cellulose coupled with continuous automated assay of activity in the column effluent. Cultured skin fibroblasts from three patients showed a profound deficiency of glucosaminidase component A and a relative increase in the activity of a form eluted earlier than A. 3. In the one patient studied, the elution profile of plasma glucosaminidase was similar to that of normal plasma, but treatment with neuraminidase revealed a minor component which did not appear in control specimens. 4. Chromatographic resolution of glucosaminidase secreted by normal fibroblasts into the culture medium shoed that component A comprised two forms, a serum-type and a tissue-type, whereas only a serum-type was found in I-cell medium. 5. Different forma of alpha-L-fucosidase were shown to occur in normal plasma and fibroblasts. This is the second lysosomal hydrolase for which differences between intracellular and extracellular forms have been described and might reflect a general phenomenon. 6. The major acidic component of fucosidase from normal fibroblasts was not detected in I-cell fibroblasts. Elution profiles of fucosidase activity in normal and I-cell plasma were indistinguishable, both before and after treatment with neuraminidase. 7. On the basis of the above findings, we suggest that for several acid hydrolases there is a common biosynthetic reaction, which produces forms of these enzymes destined for incorporation into primary lysosomes rather than secretion by the cell. In cultured fibroblasts from patients with I-cell disease, the enzyme catalysing the reaction leading to the production of intracellular forms is deficient or defective, whereas the synthesis of precursor and secreted forms is unaffected.

Acetylglucosaminidase↗
PubMed1975

Biochemical diagnosis of cystinosis using leukocytes.

A simple method for the biochemical diagnosis of cystinosis involves incubating leukocytes from a small volume of blood with 35S-cystine. Non-protein 35S-labelled compounds are then extracted from the leucocytes and separated by thin-layer chromatography. The excessive incorporation of 35S-cystine into the increased cystine pool of cystine cells is easily detected in autoradiographs of the chromatograms.

Autoradiography↗
PubMed1975

Variability of acid hydrolase activities in cultured skin fibroblasts and amniotic fluid cells.

The specific activities of lysosomal hydrolases in cultured skin fibroblasts and amniotic fluid cells showed wide and unpredictable variations between cultures, which may lead to difficulty in differentiating normal, heterozygous, and homozygous cells. However, the variability for a given culture was similar for all enzymes assayed, so that a clearer differentiation of a relative deficiency of a given enzyme could be obtained by expressing its activity in ratio to that of another enzyme. Activity ratios were particularly useful in the evaluation of enzyme levels in cultured amniotic fluid cells. Results of their application to tests of pregnancies at risk for metachromatic leucodystrophy, Krabbe's leucodystrophy, GM1-gangliosidosis, and GM2-gangliosidosis (Sandhoff variant) are presented.

Amniotic Fluid↗