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Biomedical subjects

H Shibata

Publications and source records attributed to H Shibata.

At least 271 records · Page 15Linked to original sources
PubMed1996

An allel-specific abnormal transcript of the heat shock protein 70 gene in patients with major depression.

Stress-inducible 72-kDa heat shock proteins (HSP70) were encoded on genes in multiple chromosomes. The expression of mRNA transcribed from the gene (HSP70-1) on chromosome 6 was studied using reverse transcript polymerase chain reaction in peripheral blood mononuclear cells of patients with different diseases. The deletion of 29 bp occurred in 5' noncoding and subsequent 133 bp in coding sequences of HSP70 mRNA in patients with major depression (n = 18), while normal subjects (n = 10) and patients with schizophrenia (n = 5), essential hypertension (n = 3), rheumatoid arthritis (n = 7), and Graves' disease (n = 3) had normal mRNA. No such deletion occurred in genomic DNA and no protein was translated from deleted mRNA. The allel-specific abnormal transcript of the HSP70 gene on chromosome 6 thus may underlie the altered stress and/or immune response in major depression.

Alleles↗
PubMed1996

Structure of a galactan from cell walls of Bifidobacterium catenulatum YIT4016.

A structural study was carried out on a galactose-rich polysaccharide fraction isolated from cell walls of Bifidobacterium catenulatum YIT4016 after N-acetylmuramidase digestion. The polysaccharide contained galactose and glucosamine in a molar ratio of 16.9:1.0. Data obtained by 13C NMR spectroscopy showed that the backbone chain of this polysaccharide is composed of galactofuranose residues, while the branches consist of galactopyranosyl residues. Furthermore, the data obtained from NaIO4 oxidation, partial methanolysis and methylation analysis indicated that this polysaccharide consists of a trisaccharide repeating unit having the following structure: [sequence: see text]

Bifidobacterium↗
PubMed1996

Adenoid cystic carcinoma of the esophagus: report of a case and review of the Japanese literature.

We report herein the case of a 79-year-old man with adenoid cystic carcinoma (ACC) of the esophagus. The tumor had a polypoid appearance and was covered by thin esophageal mucosa. As the biopsy specimens suggested a diagnosis of poorly differentiated adenocarcinoma, the patient underwent subtotal esophagectomy with reconstruction of the gastric tube via the posterior mediastinum. Histologically, the carcinoma contained basaloid cells, cribriform foci, and a certain amount of eosinophilic hyaline substance. Some of the basaloid cells were stained immunohistochemically for keratin, muscle actin, and S-100 protein, a pattern which was identical to the pattern of immunoreactivity of the myoepithelium. We reviewed 36 other cases of ACC of the esophagus reported in Japan, with special reference to the criteria for histological diagnosis.

Aged↗
PubMed1996

Genotyping of the ABO blood group system: analysis of nucleotide position 802 by PCR-RFLP and the distribution of ABO genotypes in a German population.

Genotypes of the ABO blood group system were studied by PCR-RFLP analysis of the eight polymorphic nucleotide positions (nps) 261, 467, 526, 646, 703, 796, 802 and 803 of the cDNA from A transferase. In 169 unrelated German individuals, 17 genotypes were found and the calculated allele frequencies of A(Pro), A(Leu), B, O(T), O(A) and O2 were 0.2130, 0.0770, 0.0473, 0.4260, 0.2160 and 0.0207, respectively. These frequency data may provide useful additional information for disputed paternity and stain testing. A variant O allele, O2, was fout at a polymorphic frequency. As the nucleotide (np 261) of the O2 allele is the same as that of A and B alleles, the analysis of at least three nucleotide positions, i.e. nps 261, 526 and 802, is necessary to avoid mistyping of the ABO genotype.

ABO Blood-Group System↗
PubMed1996

Direct projections from the entorhinal area to the anteroventral and laterodorsal thalamic nuclei in the rat.

The present study provides the evidence for the existence of direct projections from the entorhinal area to the anteroventral (AV) and laterodorsal thalamic nuclei (LD) in the rat. The retrograde tract-tracing method with cholera toxin B subunit and the anterograde tract-tracing method with Phaseolus vulgaris leucoagglutinin were used. The projection fibers originate from layers V and VI of the medial entorhinal area and terminate in the rostral and dorsolateral parts of the AV and the dorsal part of the LD. The projections are organized in a coarse topographic fashion. The rostral part of the medial entorhinal area projects preferentially to the AV whereas the caudal part projects preferentially to the LD. The results show that the medial entorhinal area is connected reciprocally with the AV and LD. Thus, the AV and LD are intimately connected with the limbic cortex implicated in memory and learning.

Animals↗
PubMed1996

Dantrolene blocks the tonic contraction and calcium influx evoked by K+ in ileal longitudinal smooth muscle.

1. Dantrolene (10(-5)-10(-4) M) reduced the K+ (60 mM) tonic response in accordance with decreased Ca2+ uptake, as determined by La method, more than the phasic in ileal muscle. 2. After saponin-treatment of the fibers, which leaves the Ca2+ storage sites intact, dantrolene had only a slight effect on the caffeine-induced contraction. In Triton-X-100-treated fibers, in which the Ca2+ release sites are destroyed, dantrolene did not affect the Ca(2+)-induced contraction. 3. The results suggest that dantrolene inhibited the high-K(+)-induced tonic response mainly by inhibiting Ca2+ influx via voltage-dependent Ca2+ channels in ileum without affecting contractile elements. In contrast, dantrolene had only a slight effect on the intracellular Ca2+ release from caffeine-sensitive release sites.

Animals↗
PubMed1996

Identification of Grf1 on mouse chromosome 9 as an imprinted gene by RLGS-M.

Normal mammalian development requires a diploid combination of both haploid parental genomes. Uniparental disomy for certain segments of specific chromosomes results in aberrant development or prenatal lethality, indicating that the parental genomes have undergone modifications during gametogenesis. These modifications result in parent-of-origin specific expression for some genes, a phenomenon called genomic imprinting. Recent work with DNA methyltransferase deficient mice showed that differential methylation is the probable basis of the imprinted character of several genes. Screening for endogenous imprinted loci using restriction landmark genomic scanning with methylation sensitive enzymes (RLGS-M) identified eight imprinted RLGS (Irigs) candidate loci. Molecular analysis of the genomic region of one of the loci (Irigs2) resulted in the discovery of the paternally imprinted U2afbp-rs gene within a previously identified imprinted region on mouse chromosome 11 (refs 5, 7). This paper describes the characterisation of a novel imprinted RLGS-M locus, Irigs3, on mouse chromosome 9 (ref. 6). Within this locus we identified the Grf1 (also called Cdc25Mm) gene, which is homologous to the RAS-specific guanine nucleotide exchange factor gene, CDC25, in Saccharomyces cerevisiae. Grf1 is located about 30 kb downstream of the methylation imprinted site, identified by RLGS-M, and shows paternal allele specific expression in mouse brain, stomach and heart. Our results indicate that imprinting may have a role in regulating mitogenic signal transduction pathways during growth and development.

Animals↗
PubMed1996

Gene frequencies of human platelet antigens on glycoprotein IIIa in Japanese.

BACKGROUND: Polymorphism of glycoprotein IIIa on human platelets is one of the factors in alloimmunization that causes neonatal alloimmune thrombocytopenia and refractoriness to platelet transfusion. STUDY DESIGN AND METHODS: DNA typing methods were originally developed to determine the genotypes of five human platelet antigen (HPA) systems located on glycoprotein IIIa: HPA-1, HPA-4, HPA-6W, HPA-7W and HPA-8W. The gene frequencies of these platelet antigens were determined by DNA typing of 331 unrelated Japanese donors. RESULTS: The gene frequencies of the low-frequency antigens were 0.002, 0.011, and 0.027 for HPA-1b, HPA-4b, and HPA-6W(b), respectively. All 331 Japanese donors tested were HPA-7W(a/a) and HPA-8W(a/a). Moreover, in the present study, none of the donors tested had two or more of these low-frequency antigens. CONCLUSION: The risk of neonatal alloimmune thrombocytopenia and refractoriness to platelet transfusion induced by the antigens of the HPA-1, HPA-7W, and HPA-8W systems was extremely rare in Japanese. However, attention must be paid to the involvement of the HPA-4 and HPA-6W systems in these clinical disorders.

Alleles↗
PubMed1996

Dysfunction of the Orleans reeler gene arising from exon skipping due to transposition of a full-length copy of an active L1 sequence into the skipped exon.

We examined the genomic structure of the reeler gene in Orleans reeler mouse mutant. Exon skipping of the reeler gene caused a 220 bp deletion in the transcript, resulting in a frame shift of the reeler gene which disrupts the 8th EGF-like motif of the reeler product. Surprisingly, the skipped exon was inserted by the 7104 bp L1 element which carried the full-length stretch of the mouse L1 sequence, consisting of a 212 bp F-type tandem repeat, open reading frame 1 (ORF1), ORF2, the polyadenylation signal and a poly A stretch. The transposed L1 sequence was flanked by 13 bp of the target sequence at both ends. ORF1 and ORF2 of this L1 repeat element are thought to encode a component of the RNP particle and the reverse transcriptase, respectively. Orleans reeler was originally established by spontaneous mutation caused by L1 insertion, and this L1 sequence is considered to be potentially active for transposition in mouse genome.

Amino Acid Sequence↗
PubMed1996

A new family of serine protease inhibitors (Bombyx family) as established from the unique topological relation between the positions of disulphide bridges and reactive site.

The positions of the reactive site and the disulfide bridges in fungal protease inhibitor F (FPI-F) from silkworm (Bombyx mori), which has a unique amino acid sequence and inhibitory specificity, were investigated. At pH 3.0, subtilisin BPN', which is one of target proteases of this inhibitor, specifically cleaved the peptide bond of the inhibitor at Thr(29)-Val(30). The cleaved bond was regenerated by subtilisin BPN' at pH 8.0. These results indicate that the Thr(29)-Val(30) bond of the inhibitor is the reactive site. The locations of disulfide bridges were determined to be Cys(3)-Cys(35), Cys(14)-Cys(27), Cys(18)-Cys(55), and Cys(37)-Cys(49). Based on the positions of the reactive site and the disulfide bridges, FPI-F is considered to be a member of a new family of serine protease inhibitors. We propose the designation Bombyx family for the new inhibitor family of which FPI-F is a member.

Amino Acid Sequence↗
PubMed1996

Molecular evolution of the 5'-flanking regions of the duplicated Amy genes in Drosophila melanogaster species subgroup.

The nucleotide sequences of the 5'-flanking regions of the duplicated Amy genes in eight sibling species belonging to the melanogaster species subgroup are analyzed. In Drosophila melanogaster, a region of about 450 bp immediately upstream of the translation initiation site of the two paralogous genes (the proximal and distal genes) has sequence similarities. However, we could not detect any significant sequence similarity in the region more upstream than -450. This result indicates that the coding regions of the ancestral Amy gene were duplicated together with 450 bp of the 5'-flanking region as one unit. Multiple alignment of these 450-bp sequences in the proximal and distal genes of all eight species revealed a mosaic pattern of highly conserved and divergent regions. The conserved regions included almost all the putative regulatory elements identified in previous analyses of the sequences. A phylogenetic analysis of the aligned sequences shows that these 450-bp sequences are clustered into the proximal and the distal groups. As a whole, the divergence between groups in this region is very large in contrast to that in the coding regions. Based on the divergence between groups, the 450-bp region is divided into two subregions. We found that the ratios of the divergence between groups to that within groups differ in the two subregions. From these observations, we discuss a possibility of positive selection acting on the subregion immediately upstream of the Amy coding region to cause divergence of regulatory elements of the paralogous genes.

Animals↗
PubMed1996

Cutaneous malignant melanoma in women is uncommonly associated with a family history of melanoma in first-degree relatives: a case-control study.

Sun exposure is the principal cause of malignant melanoma, but other risk factors may be important. During their reproductive years women are at a greater risk for melanoma than men. We performed an age-matched case-control study of cutaneous malignant melanoma in 159 women attending a single oncology clinic in Montreal. A reported family history of cutaneous malignant melanoma in first-degree relatives was associated with a significantly increased risk of melanoma (adjusted relative risk: 4.28, P = 0.046). No subject was a member of a hereditary melanoma family (three or more cases of melanoma in first-degree relatives). As expected, variables related to sun exposure were also strong determinants of risk. Height was a significant risk factor, but the difference between the mean heights of cases and controls was only 2 cm (P = 0.009). The age of menarche of cases was lower than in controls (mean 12.70 and 13.08 years respectively, P = 0.036) but there was no significant elevation in risk associated with other reproductive variables. This study suggests that a family history of malignant melanoma is a significant risk factor, but that hereditary melanoma may be less common than is currently believed.

Adolescent↗
PubMed1996

Rapid detection of the cisAB allele consisting of a chimera of normal A and B alleles by PCR-RFLPs.

DNA samples were analysed from Japanese individuals with the very rare ABO variant phenotype, cisAB (A2B3), which is characterized by the apparent inheritance of both A and B genes on one chromosome. The nature of the bases present at nucleotide positions (nps) 261, 526, 703, 796 and 803 is important for the specificity of the alleles at the ABO locus and the DNA from the cis AB donors was analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine which nucleotides are present at these positions. The results indicated that the cisAB allele had the AAAB-structure, which was a chimera of normal A and B alleles, when the expression 'AAAA' and 'BBBB' indicated the nucleotides of normal A (C, G, C and G) and B (G, A, A and C) genes at nps 526, 703, 796 and 803, respectively. The AAAB allele was found in all 27 individuals (17 families) with the cisAB including three phenotypes A2B3, A1B3 and A2B and no other chimeric gene was found. The causative gene of cisAB was the AAAB allele, and the A and B alleles were not on one chromosome. The cisAB allele appeared to be a product of the normal A allele due to a point mutation at nucleotide position 803, from G to C. The AAAB allele is thought to be normally transcribed and translated to produce an unusual transferase polypeptide, which has weak A- and weaker B-specific activity. PCR-RFLP is a rapid and useful means of detecting the cisAB allele (the AAAB allele) without a family study, even when they have A1B3 and A2B phenotypes, because trans-type A1B3 and A2B samples have obviously different PCR-RFLP profiles.

ABO Blood-Group System↗
PubMed1996

Genotype frequencies of the human platelet antigen, Ca/Tu, in Japanese, determined by a PCR-RFLP method.

Recently, the polymorphism of a new human platelet antigen, Ca/Tu, was shown to be derived from a G-A nucleotide substitution at base 1564 of GPIIIa cDNA, which leads to a single amino acid difference, Arg/Gln at amino acid 489 of GPIIIa. We developed a PCR-RFLP method to determine the genotypes of Ca/Tu and their frequencies in a Japanese population. Fifteen Ca/Tua donors comprising 1 Ca/Tu(a/a) homozygous donor and 14 Ca/Tu(a/b) heterozygous donors were found among the 314 random donors analyzed. The frequencies of Ca/Tu genes were 0.025 (Ca/Tua) and 0.975 (Ca/Tu(b)). The present study showed that the frequency of Ca/Tua individuals in the Japanese (15/314) was approximately 7-fold higher than in the Finnish population (1/150) previously reported by Kekomäki et al. Therefore, attention must be given to the involvement of the Ca/Tu alloantigen in neonatal alloimmune thrombocytopenia and the refractoriness of platelet transfusion.

Antigens, Human Platelet↗
PubMed1996

Cysteine protease of Porphyromonas gingivalis 381 enhances binding of fimbriae to cultured human fibroblasts and matrix proteins.

It has been shown that Porphyromonas gingivalis 381, a suspected periodontopathogen, possesses fimbriae on its cell surface. The organism is also known to produce proteases which can degrade the host cell surface matrix proteins. In this study, we investigated the effect of protease on the binding of the purified P. gingivalis fimbriae to cultured fibroblasts or matrix proteins. A protease that can hydrolyze benzoyl-L-arginine p-nitroanilide was obtained from P. gingivalis 381 cells by sonication in phosphate-buffered 0.2% Triton X-100 and was purified by column chromatography. The molecular size of the protease was estimated to be 55 kDa by gel filtration or 47 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The enzyme activity was markedly inhibited by sulfhydryl reagents, antipain, and leupeptin. The protease degraded various host proteins, including collagen and fibronectin, and cleaved the COOH terminus of the arginine residue in peptides such as benzoyl-L-arginine p-nitroanilide. However, P. gingivalis fimbriae were not degraded by protease activity. The enzyme activity was enhanced in the presence of reducing agents or CaCl2. When cultured fibroblasts were partially treated with the protease, the binding of the purified P. gingivalis fimbriae to the fibroblast monolayer was increased significantly. However, this enhancing effect was suppressed upon the addition of antipain and leupeptin. Similarly, binding of the fimbriae to the collagen or fibronectin immobilized on the microtiter wells was also enhanced. Addition of these host matrix proteins efficiently inhibited the binding of fimbriae to the fibroblast monolayer. The binding assay of fimbriae using dipeptidyl ligand affinity column chromatography demonstrated a clear interaction between fimbriae and the arginine residue. Taken together, these results indicate that the P. gingivalis protease at least partially degrades the host matrix proteins, which, in turn, may lead to an increased exposure of the cryptic ligands that can result in enhanced fimbria-mediated binding of this organism to periodontal tissues.

Amino Acid Sequence↗
PubMed1996

Formation of insulin-producing cells from pancreatic acinar AR42J cells by hepatocyte growth factor.

Pancreatic AR42J cells are derived from acinar cells and express both exocrine and neuroendocrine properties. We have recently shown that these cells convert into insulin-producing cells in vitro after treatment with activin A and betacellulin. Here, we investigated the effect of hepatocyte growth factor (HGF) in those cells. When AR42J cells were incubated with HGF, DNA synthesis was attenuated, and the amylase content was reduced in a concentration-dependent manner. HGF-treated cells extended processes, but bundle formation was not observed using an antibody against tubulin. Reverse both insulin and pancreatic polypeptide (PP) were expressed in HGF-treated, but not naive, AR42J cells. Immunocytochemical analysis indicated that approximately 3% of the HGF-treated cells were stained with antiinsulin antibody, and some were also stained with anti-PP antibody. When AR42J cells were exposed to a combination of activin A and HGF, cells extended longer processes, and over 10% of them were stained with antiinsulin antibody. In these cells, messenger RNAs for insulin, PP, glucose transporter 2, and glucokinase, but not those for glucagon or somatostatin, were expressed. A subclone of AR42J cells, AR42J-B13, was obtained. Most of the AR42J-B13 cells converted to insulin-producing cells after the incubation with activin A and HGF. Insulin secretion was augmented by tolbutamide, depolarizing concentrations of potassium, carbachol, and glucagon-like peptide-1 in these cells. These results indicate that HGF reduces the acinar cell-like property of AR42J cells and converts them into insulin-producing cells. The effect of HGF was markedly enhanced by activin A.

Activins↗