Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ganglioside composition of six human medulloblastomas was analyzed. The characterization was performed by thin-layer chromatography, sialidase hydrolysis, and immunological staining with a panel of characterized antiganglioside monoclonal antibodies. The total ganglioside content ranged from 60 to 1,130 nmol of ganglioside sialic acid/g wet weight. Neuronal gangliosides (gangliotetraose series) were found in varying amounts in all medulloblastomas. Gangliosides of the neolactotetraose series (3'-LM1 and LD1) were present in all specimens, and the lactotetraose series ganglioside 3'-isoLM1 was found in all cases showing astrocytic differentiation. This supports our previous findings that 3'-isoLM1 is a marker for proliferating astroglial cells.
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PMID:Determination of gangliosides in six human primary medulloblastomas. 239 61

Autopsy findings of a patient, with sialidosis type I phenotype carrying V217M/G243R mutations in the lysosomal sialidase gene and biochemically defined isolated sialidase deficiency, who died of intractable lymphoma at the age of 32 years, are described. Perikaryal expansion of cytoplasm was evident, mostly in motor neurons (in the anterior horn and the brain stem), dorsal root ganglia, cerebellar dentate neurons and some neurons in the thalamus and nucleus basalis of Meynert. The stored material was lamellar in lysosomes and exhibited a specific affinity to wheat germ agglutinin at light and electron microscopy, which indicates the accumulation of terminal sialic acid at the non-reducing end of the sugar chain in this pathological structure. Neuronal loss in these nuclei, however, was not frequent in spite of frequent and massive cytoplasmic expansion. Neocortex exhibited a mild spongiosis with some swelling of neurons, which contained lipofuscin-like granules and small amount of lamellar structures in lysosomes. This contrast suggests a discrepancy between the storage process and vulnerability of neurons, both variable according to areas examined. In the cerebellar vermis, dysplastic features, such as abnormal layering of Purkinje cells, thinning and rarefaction of the granule cell layer, incomplete formation of synapse and disordered proliferation of Bergmann's glia, were focally accentuated, suggesting some developmental abnormality not secondary to the storage process. This is the first autopsy demonstration of sialic acid in the lamellar materials and of a developmental abnormality in isolated sialidase deficiency. Additional studies are needed to clarify how this molecular abnormality leads to these morphological and clinical manifestations.
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PMID:Sialidosis type I carrying V217M/G243R mutations in lysosomal sialidase: an autopsy study demonstrating terminal sialic acid in lysosomal lamellar inclusions and cerebellar dysplasia. 1941 10

Neuronal perikarya were isolated, using bulk preparative procedures, from bovine brains. Synaptosomes, neuronal perikarya, and brain homogenates had similar ganglioside patterns, with the synaptosomes containing at least four times more total ganglioside per mg protein than the neuronal perikarya and twice that of the homogenate. Synaptosomes had 26-33 nmol total sialic acid/mg protein, while the neurons had only 15-17 nmol. Determination of ganglioside sialidase activity showed that neuronal perikarya had very low levels (negligible), in comparison with synaptosomes or whole-brain homogenates. Trypsin treatment during the isolation procedure enhanced sialidase activity two-to threefold in the particulate fraction of the whole-brain homogenate. Determination of the distribution of sialidase activity in the fractions obtained during the isolation of the neuronal perikarya showed that the sialidase activity was associated with the myelin, broken-off dendritic processes, and glial-cell fractions that banded in the less dense sucrose.
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PMID:Ganglioside sialidase activity in bovine neuronal perikarya. 2427 40