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Biomedical subjects

H Yamagata

Publications and source records attributed to H Yamagata.

At least 91 records · Page 5Linked to original sources
PubMed1994

Genetic and immunological differences between Japanese patients with diffuse scleroderma and limited scleroderma.

OBJECTIVE: To study the association between HLA-DR and scleroderma (SSc), subsets of SSc, and autoantibodies in SSc. METHODS: HLA-DR antigens were determined in 45 Japanese patients with SSc. The association between HLA-DR and SSc, subsets of SSc, and autoantibodies was analyzed in 22 patients with SSc excluding mixed connective tissue disease (MCTD)/overlap syndrome (OL). RESULTS: When the 20 patients with MCTD and 3 patients with OL were excluded from the original patient group, a significant increase of HLA-DR2 was observed (59 vs 29% of controls, p < 0.01). The frequency of DR2 increased to 69% in patients with diffuse SSc (p < 0.01). DR1, which was not found in diffuse SSc, was found in 2 of 9 patients with limited SSc. The frequency of DR2 was significantly higher in patients with antitopoisomerase I (10/12, 83%, p < 0.05). In contrast, DR1 was found only in 2 patients with anticentromere antibodies (ACA), and all 5 patients with ACA had no HLA-DR2 (p < 0.01). CONCLUSION: Our results suggest that different HLA-DR markers may be associated with the production of distinct autoantibodies in diffuse SSc and limited SSc.

Antibodies↗
PubMed1993

Very efficient extracellular production of cholera toxin B subunit using Bacillus brevis.

We have constructed a very efficient synthesis and secretion system for cholera toxin B subunit (CTB) of Vibrio cholerae 569B using Bacillus-brevis. The constructed expression-secretion vector has the multiple promoters and the signal peptide coding region of the mwp gene, a structural gene for one of the major cell wall proteins of B. brevis strain 47, directly followed by the gene encoding the mature CTB. A large amount of mature CTB (1.4 g per liter of culture) was secreted into the medium. It had the same amino terminal amino acid sequence as that of authentic CTB and was fully active in GM1 ganglioside binding assay.

Amino Acid Sequence↗
PubMed1993

Production of a fungal protein, Taka-amylase A, by protein-producing Bacillus brevis HPD31.

An expression-secretion vector, pMK300, was constructed to express the Aspergillus oryzae Taka-amylase A (Taa) cDNA. The promoter and signal peptide regions of the HWP (a major cell wall protein of Bacillus brevis HPD31) gene on pMK300 were efficiently utilized in B. brevis HPD31 and a large amount of Taa (22 mg/l) was secreted into the medium. The HWP signal peptide utilized for secretion of Taa was correctly processed during the protein transport across the membrane. The enzymatic properties of Taa produced by B. brevis HPD31 were the same as those of the Aspergillus oryzae Taa in several respects; specific activity, thermal and pH stabilities, and temperature and pH optima. These results, in combination with previous results, indicate that B. brevis HPD31 could be used to produce extracellularly foreign proteins of diverse origins as functional proteins.

Amino Acid Sequence↗
PubMed1993

A case of Sjögren's syndrome complicating immune-mediated aplastic anaemia.

A 78-year-old Japanese woman with Sjögren's syndrome complicating immune-mediated aplastic anaemia is described. A diagnosis of aplastic anaemia was made from severe pancytopenia with hypoplastic marrow. Laboratory studies suggested an association of bone marrow suppressive T-lymphocytes with the pathogenesis of aplastic anaemia. Following the administration of mepithiostan and prednisolone, pancytopenia improved gradually. Two years after the onset of aplastic anaemia, Raynaud's phenomenon developed and examinations revealed the existence of keratoconjunctivitis sicca and anti-SSA/Ro and anti-SSB/La antibodies.

Aged↗
PubMed1993

Chronic destructive monoarthritis of the wrist in patients with anti-SSA/Ro antibodies: report of two cases.

Among 340 patients with rheumatic diseases, two cases of chronic destructive monoarthritis of the wrist with anti-SSA/Ro antibodies and rheumatoid factor, were observed for over three years. It is not clear whether these cases represent a specific subset of rheumatoid arthritis (RA) or whether they may progress to diffuse symmetrical destructive polyarthritis typical of RA. Long-term follow-up studies including analysis of autoantibodies will be needed to clarify the characteristics and course of chronic monoarthritis.

Antibodies, Antinuclear↗
PubMed1993

Marked thrombocytosis with chromosomal abnormalities in a patient with rheumatoid arthritis.

An 80 year-old Japanese woman with rheumatoid arthritis (RA), complicated with thrombocytosis is described. Mild to moderate thrombocytosis is commonly observed in patients with RA, but she had marked thrombocytosis of over 1000 x 10(3)/mm3 and monosomy 22 with marker chromosome. This case suggests that thrombocytosis unusual with disease activity of RA might occur, and that careful evaluation of the thrombocytosis is required.

Aged↗
PubMed1993

Characterization of the gene encoding an intracellular proteinase inhibitor of Bacillus subtilis and its role in regulation of the major intracellular proteinase.

The gene (ipi) for an intracellular proteinase inhibitor (BsuPI) from Bacillus subtilis was cloned and found to encode a polypeptide consisting of 119 amino acids with no cysteine residues. The deduced amino acid sequence contained the N-terminal amino acid sequence of the inhibitor, which was chemically determined previously, and showed no significant homology to any other proteinase inhibitors. Analysis of the transcription initiation site and mRNA showed that the ipi gene formed an operon with an upstream open reading frame with an unknown function. The transcriptional control of ipi gene expression was demonstrated by Northern (RNA) blot analysis, and the time course of transcriptional enhancement roughly corresponded to the results observed at the protein level. Strains in which the ipi gene was disrupted or in which BsuPI was overexpressed constitutively sporulated normally. Analysis of the time course of production of the intracellular proteinase and proteinase inhibitor in these strains suggested that BsuPI directly regulated the major intracellular proteinase (ISP-1) activity in vivo.

Amino Acid Sequence↗
PubMed1993

[DNA diagnosis of myotonic dystrophy in a family].

Myotonic Dystrophy (MyD) is the most common form of muscular dystrophy affecting adults. Recently a heritable unstable DNA sequence containing CTG repeat in the region associated with MyD was detected. We have analyzed DNA from the members of an MyD family using Southern hybridization and PCR method. Unaffected individuals of this family had no expansion of unstable DNA sequence after EcoRI and BglI digestion and had CTG repeats under 12, while affected individuals had more than 0.2 kb expansion of DNA sequence and had over 50 CTG repeats. We confirmed that the length of unstable MyD region correlated with severity of the disease in a family and that the diagnosis of MyD had been improved by development of DNA probes for the CTG repeats.

Adult↗
PubMed1993

[Advances in molecular genetics of myotonic dystrophy].

Myotonic dystrophy (DM) is the most common muscular dystrophy affecting adults among Caucasian and Japanese populations, with an average incidence of 12.5 in 100,000 in Caucasians and 5.5 in 100,000 in the Japanese. Recently the DM gene was cloned and characterized showing homology with the family of serine-threonine protein kinase. In DM patients expansion of an unstable trinucleotide CTG repeat, located within the 3' untranslated region of DM kinase gene, is involved. In this review we outline the molecular biological aspects of DM including DNA diagnosis, anticipation, differences between paternal and maternal transmission, founder chromosome and expression of the gene.

Blotting, Southern↗
PubMed1992

[A case of Hashimoto's thyroiditis associated with renal tubular acidosis, Sjögren syndrome and empty sella syndrome].

This report describes a 48-year old female patient with Hashimoto's thyroiditis, distal-type renal tubular acidosis (d-RTA), Sjögren syndrome (SjS), and empty sella syndrome (ESS). She has been receiving replacement of thyroxine for Hashimoto's thyroiditis since 1967. She felt muscle weakness and numbness in the extremities and was found to have low serum potassium (2.9 mEq/l) in 1987. Since then she has been administrated potassium chloride orally. She was admitted to our hospital because of recurrence of muscle weakness and numbness of the extremities in November 1990. Laboratory examination revealed that her serum levels of antimicrosomal antibody and anti-thyroglobulin antibody were highly positive (MCHA: x 2(10) x 100, and TGHA: x 100). Furthermore, she was revealed to have 1) d-RTA by oral tolerance tests with the administration of NH4Cl and NaHCO3, 2) SjS by Schirmer test and sialography, and 3) ESS by computed tomography and magnetic resonance imaging examinations of the pituitary. Association of Hashimoto's thyroiditis, d-RTA, SjS and ESS in this case may possibly be caused by common autoimmune mechanism.

Acidosis, Renal Tubular↗
PubMed1992

Efficient production of thermostable Thermus thermophilus xylose isomerase in Escherichia coli and Bacillus brevis.

The xylose (glucose) isomerase from the thermophile Thermus thermophilus seems to have potential for the development of new isomerization processes using high temperatures and slightly acidic pH. The isomerase has an optimum temperature at 95 degrees C, and is also very stable at high temperatures. The optimum pH is around 7.0, close to where by-product formation is minimal. Since Thermus produces only a little of this useful isomerase, the production of the cloned gene in Escherichia coli and Bacillus brevis were compared. Especially B. brevis was able to produce the isomerase efficiently, more than 1 g/l, in spite of the high G + C content (67%) of the Thermus gene, and the presence of codons not frequently used in E. coli or B. brevis.

Aldose-Ketose Isomerases↗
PubMed1992

Reconstitution of the active form from the amino- and carboxyl-terminal fragments of a reactive site-modified subtilisin inhibitor of adzuki beans (Vigna angularis).

The complex of an adzuki bean subtilisin inhibitor (ASI-II) with its target enzyme, prepared at pH 7.6, was subjected to reversed-phase HPLC in a trifluoroacetic acid-acetonitrile system. Two peptide fragments derived from the reactive site-modified ASI-II were obtained. The analyses of the amino acid composition and sequence of these two fragments revealed that one corresponded to the region from the amino-terminal Lys to the reactive site P1 Ala and the other, to the region from the reactive site P1' Asp to the carboxyl-terminal Gly of the inhibitor. Although neither fragment alone showed inhibitory activity against subtilisin, an equimolar mixture of both fragments was found to inhibit strongly the target enzyme, as did the intact inhibitor. Thus, it was suggested that the two fragments have strong specific affinity with each other, regenerating the reactive site-modified ASI-II, to inhibit the target enzyme.

Amino Acids↗
PubMed1992

Mass production of sphingomyelinase of Bacillus cereus by a protein-hyperproducing strain, Bacillus brevis 47, and its purification.

Sphingomyelinase (sphingomyelin cholinephosphohydrolase) [EC 3.1.4.12] of Bacillus cereus was overproduced in a protein-hyperproducing strain, B. brevis 47, by cloning the gene into an expression vector pNU211, which has been developed to express a foreign gene utilizing a promoter and a signal sequence of an outer cell wall protein gene. From 1 liter of culture, about 10 mg of protein was purified to near-homogeneity by two steps of column chromatography; this is almost 500 times higher production compared to the conventional preparation from the original strain, B. cereus IAM 1208. The N-terminal amino acid sequence of the secreted enzyme was identical to that of the authentic enzyme, indicating that the signal sequence for secretion of B. cereus was processed properly in B. brevis 47.

Amino Acid Sequence↗