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G Ishimoto

Publications and source records attributed to G Ishimoto.

At least 19 recordsLinked to original sources
PubMed1997

A de novo recombination in the ABO blood group gene and evidence for the occurence of recombination products.

We have encountered a paternity case where exclusion of the putative father was only observed in the ABO blood group (mother, B; child, A1; putative father, O), among the many polymorphic markers tested, including DNA fingerprints and microsatellite markers. Cloning a part of the ABO gene, PCR-amplified from the trio's genomes, followed by sequencing the cloned fragments, showed that one allele of the child had a hybrid nature, comprising exon 6 of the B allele and exon 7 of the O1 allele. Based on the evidence that exon 7 is crucial for the sugar-nucleotide specificity of A1 and B transferases and that the O1 allele is only specified by the 261G deletion in exon 6 of the consensus sequence of the A1 allele, we concluded that the hybrid allele encodes a transferase with A1 specificity, resulting, presumably, from de novo recombination between the B and O1 alleles of the mother during meiosis. Screening of random populations demonstrated the occurrence of four other hybrid alleles. Sequencing of intron VI from the five hybrid alleles showed that the junctions of the hybrid alleles were located within intron VI, the intron VI-exon 7 boundaries, or exon 7. Recombinational events seem to be partly involved in the genesis of sequence diversities of the ABO gene.

ABO Blood-Group System↗
PubMed1996

Novel polymorphisms and haplotypes in the human coagulation factor XIII A-subunit gene.

Novel polymorphic sites within the coding region of the human coagulation factor XIII A-subunit (F13A) gene and their haplotypic combinations with the other polymorphic sites thus far reported are presented. Polymorphic bands were detected in exons 2, 5, 8, 12 and 14 by using single strand conformational polymorphism analysis and antithetic forms of the polymorphic exons were linked with each other, cosegregating as distinct sequence haplotypes. In Finnish, German, and Russian populations a total of 18 haplotypes were observed of possible 72 haplotypic combinations of the 5 exons. Ten of the haplotypes detected were found to have no novel mutations but to be only combinations of preexisting mutations. No tightly associated combinations in pairwise comparisons between antithetic forms of the polymorphic exons were observed, indicating that there may be recombinational hotspots within the F13A gene region.

Amino Acid Sequence↗
PubMed1993

Orosomucoid system: 17 additional orosomucoid variants and proposal for a new nomenclature.

There are two forms of orosomucoid (ORM) in the sera of most individuals. They are encoded by two separate but closely linked loci, ORM1 and ORM2. A number of variants have been identified in various populations. Duplication and nonexpression are also observed in some populations. Thus, the ORM system is very complicated and its nomenclature is very confusing. In order to propose a new nomenclature, ORM variants detected by several laboratories have been compared and characterized by isoelectric focusing (IEF) followed by immunoprinting. A total of 57 different alleles including 17 new ones were identified. The 27 alleles were assigned to the ORM1 locus, and the others to the ORM2 locus. The designations ORM*F1, ORM1*F2, ORM1*S and ORM2*M were adopted for the four common alleles instead of ORM1*1, ORM1*3, ORM1*2 and ORM2*1 (ORM2*A), respectively. The variants were designated alpha numerically according to their relative mobilities after IEF in a pH gradient of 4.5-5.4 with Triton X-100 and glycerol. For the duplicated genes a prefix is added to a combined name of two alleles, e.g. ORM1*dB9S. Silent alleles were named ORM1*Q0 and ORM2*Q0 conventionally. In addition, the effects of diseases to ORM band patterns after IEF are also discussed.

Alleles↗
PubMed1989

Venous occlusion plethysmography reduces arterial diameter and flow velocity.

The measurement of peripheral blood flow by plethysmography assumes that the cuff pressure required for venous occlusion does not decrease arterial inflow. However, studies in five normal subjects suggested that calf blood flow measured with a plethysmograph was less than arterial inflow calculated from Doppler velocity measurements. We hypothesized that the pressure required for venous occlusion may have decreased arterial velocity. Further studies revealed that systolic diameter of the superficial femoral artery under a thigh cuff decreased from 7.7 +/- 0.4 to 5.6 +/- 0.7 mm (P less than 0.05) when the inflation pressure was increased from 0 to 40 mmHg. Cuff inflation to 40 mmHg also reduced mean velocity 38% in the common femoral artery and 47% in the popliteal artery. Inflation of a cuff on the arm reduced mean velocity in the radial artery 22% at 20 mmHg, 26% at 40 mmHg, and 33% at 60 mmHg. We conclude that inflation of a cuff on an extremity to low pressures for venous occlusion also caused a reduction in arterial diameter and flow velocity.

Adult↗
PubMed1987

A case of paternity testing influenced by the silent allele of Rh erythrocyte groups.

A paternity test is presented in which a father and his two children possessed an extremely rare amorphic gene R-29 (r,---). One of the children was determined to be illegitimate at the first trial as her Rh phenotype was R2R2(ccDEE) and the father's phenotype was R1R1(CCDee). At the Court of Appeal, however, the rare Rh gene r(---) was shown to be inherited from the father to the appellant child through extended tests including her brother whose phenotype was also R2R2(ccDEE). She was acknowledged to be legitimate.

Blood Grouping and Crossmatching↗
PubMed1985

A field study of infection with human T-cell leukemia virus among asian primates.

Asian nonhuman primates were surveyed seroepidemiologically for natural infection with human T-cell leukemia virus (ATLV/HTLV) or a closely related agent. Materials from various primates (three genera [Macaca, Presbytis, and Hylobates], 17 species, totalling 1,079 animals) under natural conditions were obtained in the field study. Virus infection was determined by the indirect immunofluorescence test using HTLV-specific antigens. Animals seropositive for HTLV were found only among macaques originating from various localities, toque monkeys in Sri Lanka (17.5%), crab-eating macaques in Thailand (1.3%), stumptailed macaques in Thailand (1.5%), rhesus monkeys in Thailand (3.3%), and Celebes macaques in Indonesia (16.9%). Langurs and gibbons were seronegative. Thus the wide distribution of HTLV in nature among various macaques suggests that the introduction of this virus into primates occurred in ancient times.

Animals↗
PubMed1981

Gc revisited: six further Gc-phenotypes delineated by isoelectric focusing and by polyacrylamide gel electrophoresis.

Six newly observed Gc variants are described. The variants Gc 1A10, 1A11, 1A12, 1A13, and 1C11 have double band patterns. The anodal bands of these variants are susceptible to neuraminidase treatment. Gc 2A7 is a single band variant which is not altered by neuraminidase incubation. Polyacrylamide gel isoelectrofocusing with immunofixation and polyarcylamide gel electrophoresis appear to be efficient methods for the analysis of the Gc system.

Alpha-Globulins↗
PubMed1978

A preparative method for the isolation of genetic variant forms of glucosephosphate isomerase and a study of five variants.

A method has been developed for the rapid, quantitative separation of normal and abnormal glucosephosphate isomerase allozymes from individuals heterozygous for genetic variant forms of the enzyme. The method utilizes a substrate gradient elution of the enzyme from carboxymethyl Biogel and is far superior in terms of resolution and recovery to methods based on electrophoresis and isoelectric focusing. Five different genetic variant forms of the enzyme were isolated and subjected to a systematic comparison of their physical, catalytic and stability properties. While the physical and catalytic properties of most of the variants were similar, clear differences in the stability of the allozymes were apparent. In order to detect mutations affecting the stability, a series of different stability tests are required.

Genetic Variation↗