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Biomedical subjects

H Hamaguchi

Publications and source records attributed to H Hamaguchi.

At least 217 records · Page 12Linked to original sources
PubMed1986

Mitochondrial myopathy: tissue-specific expression of a defect in ubiquinol-cytochrome c reductase.

We have expanded our studies on a patient with a mitochondrial myopathy caused by a defect at the level of complex III of the respiratory chain. Using activity measurements, electron microscopy, protein synthesis in the presence of emetine, and antibody binding, we have demonstrated that the defect is not expressed in cultured skin fibroblasts from this patient. Electron microscopy of peripheral blood leukocytes and activity measurements in transformed lymphoid cells indicated that the defect was not expressed in these cells either. These results imply that there are either isoforms of complex III components which show differential tissue expression or that independent segregation and assortment of defective mitochondria has occurred during development.

Culture Techniques↗
PubMed1986

Genetic analysis of human lymphocyte proteins by two-dimensional gel electrophoresis. VIII. Genetic polymorphism of cytosol polypeptide with molecular weight of 20,000.

We describe a genetic polymorphism of cytosol polypeptide with mol. wt. of 20,000 detected in lymphocytes and erythrocytes by two-dimensional gel electrophoresis. Three different electrophoretic phenotypes (type 1-1, 2-1, and 2-2) of the polypeptide have been identified in a Japanese population. Family studies indicate that the phenotypes are determined by two common alleles at a single autosomal locus. The polypeptide is present in the cytosol of various kinds of cells and is abundant in erythrocytes. The data on a gel filtration of the erythrocyte cytosol proteins on a Sephadex G-100 column suggest that the polypeptide exists as a dimer in cells. In nine out of 79 individuals, the phenotypes of the polypeptide were different from those of glyoxalase 1 (GLO1) which has similar properties in subunit size, cell distribution, and allele frequencies. These data indicate that the polypeptide with mol. wt. of 20,000 is a new polymorphic cellular polypeptide. We propose that the polypeptide be temporarily designated as cytosol polypeptide with mol. wt. of 20,000 (CP20) and that the gene for CP20 be designated as CP20. The gene frequencies of two common alleles (CP20(1) and CP20(2) are 0.955 and 0.045, respectively, in a Japanese population.

Blood Proteins↗
PubMed1986

Mutagenicity of cyclosporine. Induction of sister chromatid exchange in human cells.

To examine whether cyclosporine (CsA) has mutagenic potential against human cells, we analyzed sister chromatid exchange (SCE) induction by CsA using human lymphocytes in vitro. SCE frequencies increased significantly in the lymphocytes treated with 1 microgram/ml and 5 micrograms/ml CsA, though the frequencies seemed to be less than one hundredth of those induced by mitomycin C (MMC). The value of induced SCE depended on CsA concentration. This result indicates that CsA has SCE inducibility. The data also suggest that CsA has a mutagenic effect on human lymphocytes.

Adult↗
PubMed1985

A case report of a patient with retinoblastoma and chromosome 13q deletion: assignment of a new gene (gene for LCP1) on human chromosome 13.

Retinoblastoma (Rb) occurs in hereditary, non-hereditary, and chromosomal deletion forms and the locus for the Rb gene (Rb-1) is closely linked to the locus for esterase D (ESD) assigned to the chromosome 13q14.11. We describe a patient who was predicted to have Rb from the genetic analysis of the chromosome and ESD phenotype. Furthermore, the gene for lymphocyte cytosol polypeptide with molecular weight of 64,000 (LCP1: McKusick catalogue No. 15343, 1983) was assigned to chromosome 13 by deletion mapping. A 3-month-old female had many characteristics of chromosome 13q-syndrome, including dolichocephaly, epicanthus, ptosis, depressed nasal bridge, micrognathia, short webbed neck, and short fifth fingers with clinodactyly and single crease. The karyotype of the patient was 46,XX,del(13) (q14.1-q32), though both the parents had normal karyotypes. As expected, the phenotype of ESD derived from one of the parents, the father in this case, was not detected in peripheral blood lymphocytes by two-dimensional gel electrophoresis (two-DE), indicating that ESD from the father was deleted in the abnormal chromosome 13. The possibility of paternity was calculated to be 0.996 based on the data using 22 genetic markers. Bilateral retinoblastomas could be diagnosed by ophthalmologic examinations before the manifestation of any clinical signs of the tumor and immediately intensive care was taken. In addition, the phenotype of LCP1 derived from the father was not expressed in the lymphocyte proteins from the patient. These data indicate that the gene for LCP1 (LCP1) is located in the region q14.1-q32 of chromosome 13 and may be a useful genetic marker for preclinical diagnosis of Rb.

Blood Proteins↗
PubMed1985

Genetic analysis of human lymphocyte proteins by two-dimensional gel electrophoresis. VII. Genetic polymorphism of cytosol polypeptide with molecular weight of 38,000.

We describe a genetic polymorphism of cytosol polypeptide with mol. wt. of 38,000 detected in phytohemagglutinin (PHA)-stimulated peripheral blood lymphocytes by two-dimensional gel electrophoresis. Three different electrophoretic phenotypes (type 1-1, 2-1, 2-2) of the polypeptide have been identified in a Japanese population. Family and population studies indicate that three phenotypes are determined by two common alleles at a single autosomal locus. Since the polypeptide is mainly present in cytosol of cells, we propose that the polypeptide be temporarily designated as cytosol polypeptide with mol.wt. of 38,000 (CP38) and that the gene for CP38 be designated as CP38. The gene frequencies of two common alleles (CP38(1) and CP38(2)) are 0.899 and 0.101, respectively, in a Japanese population. The data on gel filtration of cytosol proteins on a Sephadex G-100 column suggest that CP38 exists as a dimer in the cytosol. CP38 was observed in the wide range of different cells, including B-lymphoblastoid cells, adult skin fibroblasts, HeLa cells, and erythrocytes. In 11 out of 72 individuals, the phenotypes of CP38 were different from those of adenosine deaminase which is similar to CP38 in subunit size, cell distribution, and allele frequencies. These data indicate that CP38 is a new polymorphic polypeptide encoded by an autosomal locus.

Alleles↗
PubMed1985

Inhibitory effect of PWM-stimulated OKT4+ subsets on erythro-, granulo- and megakaryocytopoiesis in vitro.

Normal human peripheral blood T cells and T-cell subsets defined by monoclonal antibodies of the OKT series were pretreated with pokeweed mitogen (PWM). Their effects on the haematopoietic precursors, erythroid (BFU-E, CFU-E), granulocyte-macrophage (CFU-GM) and megakaryocyte (CFU-M) colony forming cells were evaluated by coculture. While unstimulated T cells and T-cell subsets enhanced growth of autologous blood BFU-E, PWM-stimulated T and OKT4+ cells suppressed it, also inhibiting proliferation of both autologous and allogeneic bone marrow BFU-E, CFU-E, CFU-GM and CFU-M. PWM-stimulated OKT8+ cells had little effect on the growth of any of the precursors at the cell concentration at which growth was completely inhibited by PWM-stimulated OKT4+ cells. Irradiation of T or OKT4+ cells with 3000 rad before PWM stimulation completely abrogated the inhibition. These observations might be related to the mechanism of pancytopenia in some cases of immune-mediated aplastic anaemia.

Antibodies, Monoclonal↗
PubMed1985

Specific production of eosinophil colony stimulating factor from sensitized T cells from a patient with allergic eosinophilia.

To explore the possibility that an eosinophil colony stimulating factor (EO-CSF) is elaborated independently of neutrophil CSF (N-CSF), we compared the effect on the production of EO-CSF and N-CSF of adding a specific antigen, an aspergillus extract, to peripheral blood leucocytes of an eosinophilic patient with allergic bronchopulmonary aspergillosis. Conditioned media prepared from the patient's mononuclear (MN) and T cells were assayed for EO-CSF and N-CSF activities by agar culture technique, using normal human nonphagocytic MN bone marrow cells as target cells. The addition of the specific antigen to the cultures of the patient's MN or T cells significantly stimulated the production of EO-CSF, but not that of N-CSF, while the patient's non-T cells and normal MN or T cells were not stimulated by the antigen challenge to produce either CSF. These results suggest that EO-CSF is a factor distinct from N-CSF, that its production is dependent on the presence of sensitized T cells with antigen-specific stimulation, and that it might be one of the causes of blood eosinophilia in this patient.

Antigens, Fungal↗
PubMed1985

Evidence for the close linkage between lymphocyte cytosol polypeptide with molecular weight of 64,000 (LCP1) and esterase D.

The genetic linkage of the loci for lymphocyte cytosol polypeptide with molecular weight of 64,000 (LCP1) and esterase (ESD) were examined by two-dimensional gel electrophoresis using blood from four informative families. No recombinants were observed in the four families totaling 17 children, giving a summed lod score of 4.221 at recombination fraction 0. This result indicates that the gene for LCP1 is closely linked to the ESD locus, which is assigned to the chromosomal region 13q14.11. This finding also suggests that the LCP1 locus is linked to the retinoblastoma gene, which is assigned to the same chromosomal region and closely linked to the ESD locus.

Carboxylesterase↗