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Biomedical subjects

G Dawson

Publications and source records attributed to G Dawson.

At least 289 records · Page 16Linked to original sources

Krabbe's disease: globoid cell leukodystrophy.

The clinical features of regression in mental and motor development of a 7-month-old child are reported, together with the demonstration of a profound deficiency of galactosylceramide beta-D-galactosidase in a liver biopsy. The diagnosis of Krabbe's disease or globoid cell leukodystrophy (GLD) is therefore unequivocally established. The clinical features and morbid anatomical findings permitting the diagnosis of GLD in two of the child's sibs are summarized. This is the first report from Newfoundland of this inborn error of sphingolipid metabolism.

Diffuse Cerebral Sclerosis of Schilder↗

Glycosphingolipid levels in an unusual neurovisceral storage disease characterized by lactosylceramide galactosyl hydrolase deficiency: lactosylceramidosis.

The glycosphingolipid composition of brain and visceral tissue from a patient with an unusual neurovisceral lipid storage disease, characterized by a lactosylceramide galactosyl hydrolase deficiency, was determined. Analyses of erythrocytes, plasma, bone marrow cells, urine sediment, and liver biopsy from the patient were compared with those of normal infantile controls. Abnormally high levels of lactosylceramide (GL-2a) were found in these samples. Subsequent studies on spleen, liver, kidney, lymph nodes, and adrenal gland confirmed this finding and clearly showed that the metabolism of hematoside (Gm3) and glucosylceramide (GL-1a) was also affected. The accumulation of GL-1a and Gm3 was most pronounced in spleen, but it was not of the order seen in the spleens of patients with Gaucher's disease that were studied for comparison. Since the disease was primarily neurological in nature, fresh-frozen brain was also studied. The level of GL-2a in gray matter was equal to that of galactosylceramide (GL-1b), and elevated amounts of GL-1a, asialo-Gm2, Gm2, and Gm3 were also found; the only major abnormality in white matter was the accumulation of GL-2a and lesser amounts of the gangliosides Gm3 and Gm2. Chemical and enzymic evidence suggests the use of the term "lactosylceramidosis" for this disease.

Adrenal Glands↗

Mass spectrometry of neutral, mono- and disialoglycosphingolipids.

Microgram quantities of complex glycosphingolipids were fully trimethylsilylated and analyzed by mass spectrometry. Reproducible ratios of the intensities of certain sugar fragment ions to the total intensity of ions characteristic of the sphingolipid bases were used to determine the number of monosaccharides in the glycosyl moiety and how many of them were unsubstituted at C-3. N-Acetylated hexosamine residues were readily detected and further characteristic fragment ions appeared if they were the terminal residues of the oligosac-charide chain. It was also possible to distinguish between the N-glycolyl and N-acetyl forms of neuraminic acid and to determine the number of sialic acid residues present in the lipid. Considerable information about the fatty acid and long-chain base composition was obtained from the same mass spectral analysis. It has been concluded that reliable structural information can be obtained from small amounts (less than 50 micro g) of a purified glycosphingolipid.

Acetates↗

Lactosyl ceramidosis: catabolic enzyme defect of glycosphingolipid metabolism.

A 3-year-old Negro female showed clinical evidence of a neurovisceral storage disorder that has been characterized by the specific elevation of lactosyl ceramide in erythrocytes, plasma, bone marrow, urine sediment, liver biopsy, and brain biopsy. A galactosyl hydrolase deficiency was demonstrated by the inability to cleave lactosyl ceramide labeled with tritium in the terminal galactose. The enzyme deficiency may be the primary cause of this previously unreported sphingolipidosis.

Bone Marrow↗