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Biomedical subjects

H Sakuraba

Publications and source records attributed to H Sakuraba.

157 records · Page 9Linked to original sources
PubMed1982

Galatosialidosis (beta-galactosidase-neuraminidase deficiency): clinical and biochemical studies on 13 patients.

Thirteen patients with galactosialidosis (beta-galactosidase-neuraminidase deficiency) from 9 families including two autopsy cases were studied from clinical, genetic, cytological and biochemical standpoints. Coarse facies, myoclonus, cerebellar ataxia, angiokeratoma, loss of vision, corneal opacity and cherry-red spots were the main signs and symptoms although these clinical manifestations were widely variable in individual cases. It is not yet known whether these clinical variations represent genetic heterogeneity or not. Deficiency of beta-galactosidase and neuraminidase was the most prominent biochemical abnormality in this disease. Beta-Galactosidase activity was restored in fibroblasts when serine-thiol protease inhibitors were added to the culture medium. Cathepsin B activity was significantly high in fibroblasts, liver and brain from the patients. It was demonstrated that neuraminidase was susceptible to the procedures for disrupting cells and tissues, such as sonication and freezing. The stability of this enzyme may be dependent on the molecular state in relation to cell membranes.

Adult↗
PubMed1981

beta-Galactosidase-neuraminidase deficiency in adults: deficiency of a freeze-labile neuraminidase in leukocytes and fibroblasts.

4-methylumbelliferyl neuraminidase activity was studied in fibroblasts, leukocytes, and frozen tissues from adult patients with beta-galactosidase-neuraminidase deficiency and specific clinical manifestations. This enzyme was almost completely deficient in fibroblasts, but the residual activity was relatively high (20% of the control mean) in the leukocytes from the patients. The frozen liver from one patient showed the enzyme activity as high as controls. This enzyme consisted of two components, freeze-labile and freeze-stable, and it was demonstrated that only the labile enzyme was deficient in fibroblasts and leukocytes. The apparently normal activity of neuraminidase in frozen autopsy tissues of a patient may be explained by the loss of the labile component in control tissues after a long-term freezing. The neuraminidase activity was variable in parents and no definite conclusion was drawn on the hereditary nature of the disease.

Brain↗
PubMed1981

Beta-galactosidase-neuraminidase deficiency: restoration of beta-galactosidase activity by protease inhibitors.

Beta-Galactosidase was partially restored by protease inhibitors, leupeptin, chymostatin and E-64 in cultured fibroblasts from three patients with beta-galactosidase-neuraminidase deficiency. Pepstatin did not activate this enzyme. Neuraminidase was not affected by any of these compounds in the culture medium. It was concluded that the activating effect was produced by a specific inhibition of thiol proteases.

Cells, Cultured↗
PubMedDate not supplied

Splicing defect of the glycoasparaginase gene in two Japanese siblings with apartylglucosaminuria.

Molecular analysis of the glycoasparaginase gene was performed on two Japanese siblings with aspartylglucosaminuria. The cDNA from one patient contained 7 additional bases between exons 3 and 4 (3'-terminal sequence of intron 3). This insertion resulted in a frame shift, and a termination codon appeared at amino acid 146. Amplification and sequencing of genomic DNA detected a single base transition (A-->G) at the 5' side adjacent to the insertion sequence. This mutation created a consensus AG dinucleotide in the splice acceptor site, and produced almost exclusively an abnormal mRNA containing the insertion by alternative splicing. The calculation of the sample score of the acceptor site supported this analytical result. BsmAI restriction site analysis of amplified cDNA and genomic DNA showed that these patients were homozygotes for this mutation. We conclude that the splicing defect in intron 3 causes glycoasparaginase deficiency in these patients.

Asian People↗
PubMedDate not supplied

Prenatal diagnosis of GM2-gangliosidosis. Immunofluorescence analysis of ganglioside GM2 in cultured amniocytes by confocal laser scanning microscopy.

A confocal laser scanning microscopic system was used to detect the storage of ganglioside GM2 in Tay-Sachs fibroblasts and amniocytes. The diagnosis of the disease was confirmed by counting immunoreactive cells or by digital imaging analysis. This novel system facilitates the prenatal diagnosis of GM2-gangliosidosis.

Amnion↗
PubMedDate not supplied

A case of Duchenne muscular dystrophy with truncated dystrophin. Significance of a cysteine-rich domain for functional expression of dystrophin protein.

A Duchenne muscular dystrophy case showed truncated dystrophin (320 kDa) with an isoelectric point slightly shifted towards a more alkaline pH. From the polymerase chain reaction and immunochemical analysis data, the expressed dystrophin protein was predicted to lack the portion comprising the tail of the rod-like domain, the cysteine-rich domain, and the head of the C-terminal domain. These results indicated the functional importance of the cysteine-rich domain in the dystrophin protein.

Adolescent↗
PubMedDate not supplied

Three-dimensional brain visualization for metachromatic leukodystrophy.

The basic understanding of many neurogenetic diseases requires study of the clinical, biochemical, and pathological aspects. To study the pathological aspects, the organs affected by the disease must be observed. We have used volume visualization techniques to create three-dimensional (3D) brain images of a patient with late infantile metachromatic leukodystrophy (MLD). The 3D brain images showed clearly, stereographically, and non-invasively the intracerebral lesion. This lesion, which indicated hyperintensity in magnetic resonance (MR) images, extended throughout the periventricular white matter. The 3D brain images are provided to integrate information. Volumetric ray-casting was useful in obtaining directly images of the entire brain and in allowing an intuitive understanding of the extension of the lesion in three dimensions and of the extent of the defects in the MLD brain. Isosurfacing facilitated a clear extraction of the lesion located by volumetric ray-casting. Each technique used in this study played a role in visualization and their use was complementary. 3D brain images will promote morphological investigation of neurogenetic diseases.

Brain↗
PubMedDate not supplied

Relief of chronic burning pain in Fabry disease with neurotropin.

Neurotropin, an extract from the inflamed skin of vaccinia virus-inoculated rabbits, was effective in the relief of sharp or burning pain induced by pyrexia, hot weather, bathing, or exercise in 2 siblings with Fabry disease. Neither neurotropin nor carbamazepine mono-therapy relieved the episodic colicky pain in 1 patient; however, therapy with both drugs eliminated the pain completely. This result suggests that the mechanisms underlying the analgesic actions of both drugs may be complementary in ameliorating the pain of Fabry disease, even though the mechanism underlying the pain has not been clearly elucidated.

Adolescent↗