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Biomedical subjects

G Isshiki

Publications and source records attributed to G Isshiki.

100 records · Page 6Linked to original sources

[Menkes syndrome].

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Brain Diseases, Metabolic↗

Prenatal diagnosis and fetal pathology of Tay-Sachs disease.

In 6 cases of high risk pregnancies for Tay-Sachs disease, prenatal diagnosis was successfully carried out by examining hexosaminidase A activity in the supernatant of amniotic fluid and the uncultured and cultured amniotic fluid cells. In 5 out of 6 cases, the activity of hexosaminidase A was found to be within normal or heterozygous levels. They continued their pregnancies and were delivered of healthy children. In the remaining 1 case, the activity was undetected. Her pregnancy was terminated at the 23rd week of gestation. There was no activity of hexosamindase A in the brain and liver from the aborted fetus. A moderate increase in GM2 ganglioside was found in the brain. Electron-microscopic findings revealed membranous cytoplasmic bodies in the spinal ganglion cells as well as in the nerve cells of the retina. These biochemical and histological findings of Tay-Sachs fetus suggest that the disease proceeds early in fetal period. It was found that the cultured amniotic fluid cells was the most reliable material for the prenatal diagnosis of Tay-Sachs disease, because the values of hexoxaminidase A in the cultured cells were well in accord with those in serum from the consequently bord children. Hexosaminidase pattern in the supernatant of amniotic fluid on DEAE-cellulose columnchromatogram showed a distinct difference between homozygote, heterozygote and normal. This procedure also may be useful for prenatal diagnosis of Tay-Sachs disease.

Amniocentesis↗

Lack of expression of antigens for islet cell antibodies in rat fetal pancreas.

It is not clear yet when pancreatic islet cells begin to express antigens for islet cell antibodies (ICA). Therefore, we studied whether human ICA-positive sera, crossreacting with adult rat islet cells, react with fetal and neonatal rat islet cells immunohistologically. The ICA did not react with fetal islet cells. On the other hand, neonatal islet cells over 2-3 weeks of age expressed the reactivities almost similar to those of the adult. It was suspected that pancreatic islet cells started to express their antigens to induce ICA gradually after birth.

Aging↗

Molecular basis for phenotypic heterogeneity in galactosaemia: prediction of clinical phenotype from genotype in Japanese patients.

We identified 14 mutations in 15 Japanese subjects from 13 families with galactose-1-phosphate uridyltransferase (GALT) deficiency using denaturing gradient gel electrophoresis (DGGE) and direct sequence analysis. These mutations accounted for 22 (96%) of 23 mutant alleles in 15 Japanese subjects. The mutational spectrum included nine missense mutations (M142V, G179D, A199T, R231H, W249R, N314D, P325L, R333Q, and R333W), two deletions (L275fsdelT and Q317fsdelC), a nonsense mutation (W249X), and two splicing mutations (V85-N97fsdel38bp and IVS4nt+1). Ten of the 14 mutations have not been reported in Caucasians. Differences in frequency and spectrum of GALT mutations suggest that the mutations may have occurred after racial divergence of Caucasians and Asians. The Duarte variant in Japanese was associated with the N314D mutation, g.1105G > C, g.1323G > A, and g.1391G > A (SacI -) polymorphisms, as in Caucasians. The Duarte variant may have occurred before racial divergence, and was an ancient mutation. In vitro GALT activities of nine missense mutations were determined by a COS cell expression system, and indicated between 1.3% and 35% of wild-type control. Patients with R333Q (29% in vitro GALT activity) or A199T (35%) showed mild clinical phenotypes, i.e. no ovarian failure or neurological deterioration. Genotype determination is useful for predicting biochemical and clinical phenotypes in classic galactosaemia, and can be of further help in managing patients with this disorder.

Adolescent↗