Biomedical subjects

I Yuasa

Publications and source records attributed to I Yuasa.

At least 37 records · Page 2Linked to original sources

PubMed1999

Missense mutations in the phosphomannomutase 2 gene of two Japanese siblings with carbohydrate-deficient glycoprotein syndrome type I.

Carbohydrate-deficient glycoprotein syndrome type I (CDG1) is an autosomal recessive disorder characterized by severe nervous system involvement and a carbohydrate moiety deficiency in N-linked glycoproteins. Clinical symptoms are psychomotor retardation, stroke-like episodes or hemorrhagic episodes, hepatic dysfunction, polyneuropathy, and cerebellar ataxia. Marked atrophy of the cerebellar hemispheres and pons is recognizable on CT scan or MRI. CDGI has been mapped to human chromosome 16p by linkage studies. Recently, missense mutations in the gene for phosphomannomutase (PMM2) have been detected in Caucasian patients with CDG1. We studied DNA mutations in PMM2 in a Japanese family with CDG1. DNA sequencing of PMM2 in the siblings showed missense mutations of maternal origin in exon 5 and of paternal origin in exon 8. No such mutations were detected in 50 unrelated healthy Japanese. These findings suggest that the PMM2 is responsible for CDG1 in the Japanese as well as in Caucasians, and CDG1 may be the diagnosis in OPCA of neonatal onset, more often than currently thought.

Adolescent↗

PubMed1999

Missense mutations in phosphomannomutase 2 gene in two Japanese families with carbohydrate-deficient glycoprotein syndrome type 1.

Carbohydrate-deficient glycoprotein syndrome type 1 (CDG1) (MIM: 212065) is an autosomal recessive disorder with psychomotor retardation, strokelike episodes, ataxia, and olivopontocerebellar atrophy (OPCA) of neonatal onset. Recently, DNA substitutions in a gene for phosphomannomutase 2 (PMM2), mapped to 16p13, were identified in patients with CDG1. Biochemical findings in previously reported Japanese patients with CDG1 were slightly different from those of Caucasians, suggesting genetic heterogeneity of CDG1 in Japanese patients. We investigated the DNA sequence of PMM2 in two unrelated Japanese families with CDG1. Missense mutations in exon 5 (Phe144Leu) and exon 8 (Tyr229Ser, Arg238Pro) of the PMM2 gene were present in two families, but they were not present in 72 unrelated healthy Japanese individuals. One of the missense mutations, Phe144Leu in exon 5, was common to two families with CDG1. Our findings confirm that mutations in the PMM2 gene account for at least some Japanese patients with CDG1 similar to that seen in Caucasians and that exons 5 and 8 are hot spots of mutations of CDG1 caused by the PMM2 gene.

Adolescent↗

PubMed1998

Simultaneous genotyping of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2) loci by amplified product length polymorphism (APLP) analysis.

Genotyping of the alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2) loci is important in alcohol studies. We describe a method for simultaneous genotyping of ADH2 and ALDH2 based on amplified product length polymorphism (APLP) analysis. Two polymerase chain reaction (PCR) fragments for ADH2 (57 bp, 53 bp) and two for ALDH2 (78 bp, 73 bp) are simultaneously amplified. Nine banding patterns reflecting the genotypes of the ADH2 and ALDH2 loci are clearly and unambiguously distinguished. The APLP method seems to be particularly suited for large-scale population studies of ADH2 and ALDH2 loci because it is simple and rapid.

Alcohol Dehydrogenase↗

PubMed1998

Idiopathic renal arteriovenous fistula demonstrating a huge aneurysm with a high risk of rupture: report of a case.

This paper reports a case of an idiopathic renal arteriovenous fistula demonstrating a huge guitar-shaped aneurysm, which required a total nephrectomy. Although the patient insisted on having been asymptomatic, echocardiography and cardiac catheterization clearly revealed that the influence on hemodynamics was unexpectedly significant. Interestingly, the aneurysm was also considered to have a high risk of rupture, which was preoperatively suggested by an aneurysm wall projection discernible on both computerized tomograms and angiograms, and this suspicion was also convincingly supported by the perioperative and histopathological findings.

Aneurysm↗

PubMed1998

Increased expression of beta-hexosaminidase alpha chain in cultured skin fibroblasts from patients with carbohydrate-deficient glycoprotein syndrome type I.

Carbohydrate-deficient glycoprotein (CDG) syndrome type I is an autosomal recessive multisystem disorder characterized by multiple serum glycoproteins with deficient oligosaccharide chains. This characteristic under-glycosylation is found in several serum glycoproteins. We studied secreted forms of lysosomal enzymes, beta-hexosaminidase and alpha-fucosidase, in serum from the patients and media of cultured fibroblasts. Both beta-hexosaminidase and alpha-fucosidase activities were increased in sera from three CDG patients. The enzyme activity staining using the fluorogenic substrate-4-methylumbelliferyl-alpha-L-fucopyranoside after polyacrylamide gel isoelectric focusing revealed abnormal cathodal bands in sera from CDG patients. On the other hand, no abnormal secreted forms of beta-hexosaminidase and alpha-fucosidase were detected in media from cultured CDG fibroblasts by isoelectric focusing and sodium-dodecyl sulfate-polyacrylamide gel electrophoresis. However, SDS-polyacrylamide gel electrophoresis and Western blotting analysis of beta-hexosaminidase using anti-beta-hexosaminidase A (anti-alpha + beta chains) antibody, showed an increase of a 55-kDa mature form of the alpha chain. Northern blotting analysis identified an increase in mRNA levels of beta-hexosaminidase alpha chain in CDG fibroblasts. Although under-glycosylated fractions of these lysosomal enzymes were not detected in cultured fibroblasts, it was suggested that intracellular processing of these lysosomal enzymes in CDG patients might be altered.

Blotting, Northern↗

PubMed1998

Neonatal hyperbilirubinemia and mutation of the bilirubin uridine diphosphate-glucuronosyltransferase gene: a common missense mutation among Japanese, Koreans and Chinese.

We analyzed the bilirubin uridine diphosphate-glucuronosyltransferase (B-UGT) gene in 42 Japanese newborns with hyperbilirubinemia and determined that 21 infants were heterozygous while 3 was homozygous for Gly71Arg. Allele frequency of Gly71Arg was 0.32 in newborns with hyperbilirubinemia, which was significantly higher than 0.13 in healthy Japanese controls. This mutant allele is also prevalent among Korean and Chinese healthy controls with a frequency of 0.23 in both populations. However, this mutation was not detected in 50 healthy German controls. These data suggest that the high frequency of the Gly71Arg mutation of the B-UGT gene is associated with high incidence of neonatal hyperbilirubinemia in Japanese, Korean and Chinese populations.

Alleles↗

PubMed1998

Mutation in the exon 10 (R173W) of the hydroxymethylbilane synthase gene in two unrelated Japanese families with acute intermittent porphyria.

Acute intermittent porphyria (AIP) is an inherited disorder characterized by a deficiency of hydroxymethylbilane synthase (EC 4.3.1.8.; HMBS), the third enzyme in the heme biosynthetic pathway. To date, 113 different HMBS gene mutations have been reported in the world. However, there were a few reports of the gene mutations in the Japanese AIP patients. We studied the gene mutation in two unrelated AIP families in the San-in district, a local area of Western Japan. The overlapping 6 fragments of the HMBS gene, amplified by the reverse transcript-polymerase chain reaction, were analyzed by the single-strand conformation polymorphism with silver staining technique. The abnormal fragment from a member of one family was sequenced to detect the C to T substitution at 517 nucleic acid position of cDNA, which led to a missense mutation of arginine to tryptophan exchange at an amino acid level (R173W). This mutation located in exon 10 created a new site of the MSP 1 restriction endonuclease and was screened by the amplified fragment of exon 10 from genomic DNA with the MSP 1 digestion. The mutation was detected totally in three members of the family and interestingly also in two patients of an unrelated family. This mutation has been reported widely in the world independently, such as in a Swedish, a Canadian, a Finnish, and a French family, but is the first in Japanese patients. The screening method for this mutation is useful for diagnosis in Japanese AIP patients.

Adult↗

PubMed1998

Simultaneous determination of STR polymorphism and a new nucleotide substitution in its flanking region at the CD4 locus.

In the course of the investigation of a pentanucleotide repeat polymorphism at the human CD4 locus, a C-A transversion was found at the position corresponding to the 3' end of the original forward primer presented by Edwards et al. (1). In the present study, the simultaneous determination of the new sequence polymorphism and the pentanucleotide repeat polymorphism at the CD4 locus was attempted. To achieve this purpose, we adopted amplified product length polymorphism (APLP) analysis and designed some new allele-specific forward primers tagged with non-complementary nucleotides differing in length. A total of 646 DNA samples from peripheral blood of Japanese, Chinese and German populations were investigated. Although the C-A transversion was restricted to CD4*5, a new subtype allele with A and 5 repeats, designated CD4*5A, was observed at polymorphic frequencies in the three populations. The simultaneous genotyping by APLP analysis resulted in dramatically increased heterozygosity and discriminating power of the human CD4 locus.

Base Sequence↗

PubMed1997

Nucleotide substitution in the 5' flanking region of D1S80 locus.

We have analyzed a mutation responsible for a Hinf I polymorphism of the D1S80 system by Taq dye deoxy terminator cycle sequencing. A G-T transversion at the 58th nucleotide from the 5' end of the forward primer was identified. This mutation has been firmly established by the restriction enzymes. The type G was digested with Hinf I but not with Tsp 509 I. Conversely, the type T was digested with Tsp 509 I but not with Hinj I. We applied this technique to analyze D1S80 system in German and Japanese populations. In the Japanese population, the type T frequencies were much lower than those in the German population, and the type T was almost exclusively observed in the allele 24.

Base Sequence↗

PubMed1997

Serum carbohydrate-deficient transferrin in patients with nonalcoholic liver disease and with hepatocellular carcinoma.

Serum carbohydrate-deficient transferrin (CDT) is used as a reliable and specific marker of alcohol consumption. However, recent studies have shown false-positive CDT test results in nonalcoholic liver disease. We examined the clinical significance of serum CDT in nonalcoholic liver disease, especially hepatocellular carcinoma. Serum CDT was measured in 23 teetotallers, 56 patients with alcoholic liver disease, 84 patients with viral liver disease and 67 patients with hepatocellular carcinoma, with an Axis %CDT radioimmunoassay kit, and the results were expressed as percentages of the total transferrin (%CDT). The mean serum %CDT value was increased 1.8-fold in alcoholic liver fibrosis and 3.8-fold in alcoholic liver cirrhosis compared with the teetotallers. The serum %CDT values in viral chronic hepatitis were similar to those of the teetotallers, and were increased 2.0-fold in viral liver cirrhosis. False-positive results were found in 10 (37%) of the 27 patients with viral liver cirrhosis. The mean serum %CDT value was increased 2.5-fold in hepatocellular carcinoma, and false-positive results were found in 31 (46%) of the 67 patients. The serum %CDT value was related to the severity of Child grade, the size of tumor and the grade of histological differentiation. These results suggest that the ability of serum CDT test to detect chronic alcoholism may be reduced in patients with nonalcoholic liver cirrhosis and those with hepatocellular carcinoma.

Adult↗

PubMed1997

The fifth allele of the human deoxyribonuclease I (DNase I) polymorphism.

The fifth allele, DNASE1*5, of human deoxyribonuclease I (DNase I) has been discovered. Polymerase chain reaction fragments containing exon 5 of the DNase I gene were screened for DNA polymorphism using single-strand conformation polymorphism (SSCP) analysis. DNAs from 114 unrelated Japanese and 81 German individuals were tested and a new variant was detected. By DNA sequencing analysis, this variant was found to be caused by a heterozygous G-A transition at nucleotide position 1227 that results in a Val to Met substitution at amino acid position 92 of the mature enzyme. The nucleotide substitution was also confirmed by mismatched polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis. Genotyping of the variant could be carried out by three independent reactions based on PCR amplification, and phenotyping by isoelectric focusing followed by immunostaining. The results supported the presence of the fifth codominant allele, DNASE1*5, which generates a new isozyme.

Alleles↗

PubMed1997

Simple and rapid determination of the acetaldehyde dehydrogenase (ALDH2) genotypes by nonradioactive single-strand conformation polymorphism analysis.

The genotyping of mitochondrial acetaldehyde dehydrogenase (ALDH2) is very important in alcohol studies. We describe an ALDH2 genotyping method based on nonradioactive single-strand conformation polymorphism (SSCP) analysis on mini-gels following amplification with a mutated primer set. The three ALDH2 genotypes were clearly and unambiguously distinguished. This method was applied to the ALDH2 genotyping of 129 unrelated Japanese. The allele frequency of ALDH2*2 was calculated to be 0.271, which was consistent with the previous data. The method proved to be simple, rapid and reliable, and dispensed with isotopic reagent and expensive restriction enzymes and equipment. The SSCP method described here is valuable in routine ALDH2 genotyping.

Aldehyde Oxidoreductases↗

PubMed1997

ITIH1*Q0iwate, a null allele of inter-alpha-trypsin inhibitor H1 caused by deletion/frameshift mutation.

The molecular characterization of the first example of null allele in the inter-alpha-trypsin inhibitor H1 (ITIH1) system, ITIH1*Q0iwate, encountered as apparent inverse homozygosity of ITIH1 phenotypes between mother and child in a paternity case, is described. Single-strand conformation polymorphism analysis and subsequent sequencing showed that deletion of a single nucleotide in the codon for Lys87 results in a frameshift causing a terminator codon downstream of the deletion. This leads to premature termination of ITIH1 protein translation at amino acid 128, resulting in a truncated protein.

Alleles↗

PubMed1997

Amplified product length polymorphism (APLP): a novel strategy for genotyping the ABO blood group.

We present a simple rapid reproducible polymerase chain reaction based technique, termed amplified product length polymorphism (APLP), as a new strategy for primer design for ABO genotyping. The method involves the use of primers differing in length and permits the identification of the major ABO genotypes (A1, A2, B, OA, OG, and O2) according to the molecular size of the allele-specific amplified products. Ten different primers designed to analyze the variations in nucleotide positions 261, 297, 796, 802, and 1059-1061 of cDNA are mixed in one reaction, and the amplified products are resolved on a polyacrylamide gel. Of eight PCR fragments (132 bp, 120 bp, 108 bp, 98 bp, 88 bp, 80 bp, 72 bp, and 64 bp), two to five are amplified in the reaction according to ABO genotypes. The new technique has been successfully applied to the genotyping of 221 peripheral blood samples from Japanese and Germans whose ABO phenotypes had previously been determined; a novel A allele (AG) was found in Japanese individuals.

ABO Blood-Group System↗

PubMed1997

Human orosomucoid polymorphism: molecular basis of the three common ORM1 alleles, ORM1F1, ORM1F2, and ORM1*S.

The human orosomucoid (ORM) is controlled by two closely linked loci, ORM1 and ORM2, and two tandem genes, AGP1 and AGP2, encoding the proteins produced by the two loci, have been cloned. In this study the molecular basis of ORM1 polymorphism was investigated. For the detection of mutations the products of the six exons of each gene, amplified by the polymerase chain reaction (PCR), were screened by single-strand conformation polymorphism analysis. Subsequently, the exons with an altered migration pattern were gene-specifically amplified by nested PCR. Sequencing of the gene-specific PCR products showed that the three common ORM1 alleles result from A-->G transitions at the codons for amino acid positions 20 in exon 1 and 156 in exon 5 of the AGP1 gene: ORM1*F1 was characterized by CAG (Gln) and GTG (Val), ORM1*F2, by CAG (Gln) and ATG (Met), and ORM1*S, by CGG (Arg) and GTG (Val). The phylogenesis of the genes encoding these three ORM1 alleles is discussed.

Alleles↗

PubMed1997

Genetic polymorphisms of orosomucoid ORM1 and ORM2 in Egyptians, Sudanese, and Qataris: occurrence of two new alleles.

Isoelectric focusing was used to investigate the genetic variants of the human plasma orosomucoid ORM1 and ORM2 gene loci in samples of Egyptians, Sudanese, and Qataris. The study populations were classified into 28 ORM phenotypes determined by 10 ORM1 and 9 ORM2 alleles that included 2 new alleles, designated ORM1*B13 and ORM2*H21. Family studies of these new alleles are in accordance with codominant autosomal inheritance. A new interpretation for two previously reported alleles, ORM1*C6 and ORM2*H17, is also presented.

Alleles↗

PubMed1997

[A simple technique for the genotyping of TH01 locus].

It is difficult to differentiate between type 9.3 and 10 at the TH01 locus. Therefore, we designed three primers including allele-specific primer for the type 9.3. Our primer sets gave shorter fragments ranging from 62 to 81 bp than those in other reports, allowing each allelic band to be resolved by 10% non-denaturing polyacrylamide gel electrophoresis and stained with SYBR Green I. TH01 typing was successfully applied to human remains such as sera, whole bloods and blood stains made about 80 years ago without extracting DNA from them. The simple and fast methods for TH01 typing as demonstrated herein will be useful in the field of forensic practice.

Base Sequence↗

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↗