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Biomedical subjects

K Omoto

Publications and source records attributed to K Omoto.

At least 55 records · Page 3Linked to original sources
PubMed1990

Restriction fragment length polymorphism of complement C4 in Japanese patients with rheumatoid arthritis and normal Japanese.

Restriction fragment length polymorphism (RFLP) of the two genes for complement C4A and C4B was studied in 56 Japanese patients with rheumatoid arthritis (RA) and 161 normal individuals. HindIII digestion revealed six common patterns, from which the segregation of three common RFLP-types were deduced; 32-15 kb, 32-25 kb, and 32-20-13-6.5 kb. The last type showed positive associations with C4B5 and HLA-DR4. In the RA patients, an increase of this type was found as well as a decrease of the 32-15 kb/32-25-15 kb heterozygotes.

Arthritis, Rheumatoid↗
PubMed1989

Putative amino acid sequence of HLA-DRB chain contributing to rheumatoid arthritis susceptibility.

The association between HLA-DR4 and rheumatoid arthritis (RA) has been established in many ethnic groups. To clarify the determinant of susceptibility to RA, a polymorphic segment of the HLA-DRB gene was amplified in vitro by polymerase chain reaction and analyzed with oligonucleotide probes specific for the HLA-DR4 DNA sequences. A particular sequence encoding amino acids Gln70-Arg71-Arg72-Ala73-Ala74 showed a strong association with RA (p less than 0.005, relative risk 6.0). This amino acid sequence occurs in the DRB molecules with three RA-associated specificities, DR4/Dw14, DR4/Dw15, and DR1. DR4/Dw4, which is common in Caucasian RA patients, has a strikingly similar amino acid sequence Gln70-Lys71-Arg72-Ala73-Ala74 in terms of polarity and charge profiles. Other RA nonassociated sequences differ from this sequence by at least one amino acid substitution that causes the change of the net charge. The composition of amino acid residues at the positions 70-74 may play a crucial role in the pathogenesis of RA.

Amino Acid Sequence↗
PubMed1989

Nucleotide sequences of immunoglobulin-epsilon pseudogenes in man and apes and their phylogenetic relationships.

To understand the phylogenetic relationships between hominoids, the nucleotide sequences of immunoglobulin-epsilon processed pseudogenes from chimpanzee, gorilla and orangutan were determined. The basic structures of these processed pseudogenes agreed with their human counterpart. Although the degrees of nucleotide differences between man and the African apes had no statistical significance, all the analytical data examined supported the theory that chimpanzee is the closest relative of man. This result was consistent with that deduced by our recent qualitative study. Studies on the nucleotide sequences of globin genes have suggested that the molecular clock runs more slowly in hominoids than in non-hominoid primates. According to the present data, however, further retardation of the evolutionary rate was not observed in the human lineage. Assuming that orangutan diverged 14 million years ago and that the evolutionary rate between the orangutan lineage and the lineage leading to the other three species is constant, the divergence dates of chimpanzee and gorilla were estimated to be 4.9(+/- 0.9) and 5.9(+/- 0.9) million years ago, respectively.

Animals↗
PubMed1989

Association of complement alleles C4AQ0 and C4B5 with rheumatoid arthritis in Japanese patients.

We investigated polymorphisms of complement components C2, C4, and factor B (BF) in Japanese patients with rheumatoid arthritis (RA). The frequencies of C4AQ0 (32.1%) and C4B5 (35.9%) among RA patients were significantly higher than among healthy control subjects. C4B5 was strongly associated with HLA-Bw54, Bw59, DR4.1, and DQw4. C4AQ0 showed no association with HLA-Bw54 or Bw59, but there was weak association with HLA-DR4.1 and DQw4. The number of persons with both C4AQ0 and C4B5 was significantly higher in the RA patient group (relative risk 13.5). C2C and BFS were the most common alleles in RA patients, as well as in healthy control subjects. These data support the existence of 2 different putative susceptibility haplotypes (HLA-Bw54 or Bw59;C2C; BFS;C4A3;C4B5;DR4.1;DQw4 and C2C;BFS; C4AQ0;C4B1 or C4B2) in Japanese patients with RA.

Alleles↗
PubMed1989

The DNA polymorphisms of the beta-globin gene cluster and the arrangements of the alpha- and the gamma-globin genes in Koreans.

The DNA polymorphisms at the seven restriction sites in the beta-globin gene cluster in healthy Koreans were examined using four restriction endonucleases, Hinc II, Hind III, Ava II, and Bam HI. Seven (f = 0.326) and four individuals (f = 0.246) were homozygous for [+-----+] and [+----+-], respectively, among 66 individuals examined. As to the subhaplotypes 5' to the delta-globin gene, 25 (f = 0.615) and three individuals (f = 0.213) were homozygous for [+----] and [-+-++], respectively. The frequency of [-++-+], which carries the A gamma T-globin gene, may be low in this population. It was recognized again that [+/+] at the Hinc II site 5' to the epsilon-globin gene always accompanied [--+--] at the Hinc II sites in and 3' to the psi beta 1-globin gene. The Korean, Japanese, and Chinese populations were not significantly different from each other in their haplotypes (subhaplotypes). The frequencies of the abnormal alpha- and gamma-globin gene arrangements in Koreans were low. alpha-Thalassemia may occur at low frequency in Koreans.

China↗
PubMed1989

[Family study on mitochondrial DNA polymorphism].

Mitochondrial DNA restriction fragment length polymorphisms (mtDNA RFLPs) were surveyed among 19 Japanese families with 67 individuals including twins. A mother and children, and siblings of each family showed the same pattern of mtDNA RFLPs. Samples from Japanese war orphans remained in China and their probable relatives were also surveyed and one pair indicating a high probability to be siblings using other genetic markers possessed the same variant of mtDNA. Moreover mtDNA RFLPs was applied for maternity test among two families. The data suggested that parents mistook their children for each other at birth.

Adult↗
PubMed1989

[The experimental study on long-term cardiac preservation: the efficacy of low-flow continuous perfusion with fluorocarbon].

We compared the effect of simple immersion and continuous perfusion on long-term cardiac preservation, and evaluated the effectiveness of perfusion with oxygenated fluorocarbon solution. The isolated rabbit hearts were preserved for 24 hours at 4 degrees C using the following five preservation techniques: (1) simple immersion with Collins M solution (Group I), (2) perfusion with oxygenated Collins M solution at a flow rate of 10 ml/hr (Group II), (3) perfusion with the same solution as in Group II at a flow rate of 20 ml/hr (Group III), (4) perfusion with oxygenated Collins M solution containing 10% fluorocarbon at a flow rate of 10 ml/hr (Group IV), (5) perfusion with the same solution as in Group IV at a flow rate of 20 ml/hr (Group V). The hearts of Group I showed a significant decrease of myocardial ATP and an increase of myocardial lactate during preservation compared to the hearts of perfusion groups. Assessment of isovolumic left ventricular function following 24-hour preservation using a support animal showed a significant decrease of Max dp/dt and increase of end-diastolic pressure in the hearts of Group I. Perfusion with fluorocarbon (Group IV and V) significantly increased oxygen consumption compared to Group II and III in association with minimum accumulation of myocardial lactate, indicating that aerobic metabolism during preservation is better maintained in the fluorocarbon-perfused hearts. Moreover, CPK release and myocardial water gain during preservation were significantly less, and left ventricular function following preservation was significantly better in these hearts. Increasing the flow rate from 10 ml/hr to 20 ml/hr resulted in sustained increase in perfusion pressure (1.80 +/- 0.53 to 3.70 +/- 0.34 mmHg) and myocardial water content (79.2 +/- 0.4 to 87.2 +/- 0.3%) during preservation in the hearts of Group III, but it did not further improve left ventricular function despite significant enhancement of myocardial oxygen uptake in both Group III and V. These results suggest that hypothermic low-flow continuous perfusion with oxygenated Collins M solution is superior to simple immersion with the same solution for long-term cardiac preservation, and that the addition of fluorocarbon to the perfusate enhances the efficacy of such a perfusion.

Animals↗
PubMed1989

[Genetic variants of the complement components and HLA-antigens associated in patients with psoriasis vulgaris in Japanese].

Genetic polymorphisms of the serum complement components (C2, C4, C6, and C7) and HLA-antigens were studied in Japanese patients with psoriasis vulgaris. Among these complement components, positive associations with C4A4 and C4B2 were obtained. In addition to the previously reported haplotypes HLA-Cw6-B13 and Cw6-Bw57-DR7, the extended haplotype HLA-Cw11-Bw46-C4A4. 4B2-BFS-C2C-DRw8 may be a high risk haplotype in Japanese patients with psoriasis vulgaris.

Asian People↗
PubMed1988

A seroepidemiological survey of HTLV-1 in the Philippines.

The prevalence of human T-lymphotropic retrovirus type-1 (HTLV-1) was examined in the Asian Pacific area to search for endemic foci outside Japan. A total of 1323 sera from healthy subjects in the Philippines including Filipino lowlanders, Mongoloid slash-and-burn agriculturalists and the Mongoloid aboriginal hunter-gatherers (Aeta group and Mamanwa group) were examined for the presence of antibodies to HTLV-1 by the indirect immunofluorescence test and by the Western blot technique using HTLV-1 carrying cells. Nineteen out of 20 HTLV-1 antibody carriers found in the present study are clustered in the Aeta group of Mongoloid aboriginal hunter-gatherers who have until recently been isolated in the remote mountainous areas of Luzon Island since their arrival in the Philippines during the last glacial era (12,000-15,000 years ago). This finding supports the theory that HTLV-1 originated in Mongoloid racial groups during prehistoric times.

Adolescent↗
PubMed1988

Mega base map of the epidermal growth factor (EGF) receptor gene flanking regions and structure of the amplification units in EGF receptor-hyperproducing squamous carcinoma cells.

We have established a mega base scale physical map of the 5'- and 3'-flanking regions of the epidermal growth factor (EGF) receptor gene using CpG-recognition rare-cutting restriction enzymes and pulsed-field gel electrophoresis. In this map, a methylation-free CpG island (HTF island) is located within an 8-kilobase pair (kb) EcoRI fragment which includes exon 1 of the EGF receptor gene. From this HTF island, a 390-kb NotI fragment was identified as the longest 5'-flanking region and a 540-kb MluI fragment as the longest 3'-flanking region. Utilizing this map information, we have analyzed the structure of the flanking regions of amplified EGF receptor genes which are found in various squamous carcinoma cells. Among seven cell lines tested, four cell lines carrying EGF receptor genes in amounts more than 20 times that of normal cells showed amplification together with large 5'- and 3'-flanking regions. The amplified 5'-flanking regions were rearranged in different forms but were distinct in each cell line. The amplified 3'-flanking regions were at least 540 kb in size and common to all the cell lines, except that A431 had rearrangement points within 540 kb downstream of the HTF island. Thus, the size of amplification units appears to be large and different in each cell line.

Carcinoma, Squamous Cell↗
PubMed1988

Mitochondrial DNA polymorphism among five Asian populations.

Mitochondrial DNA (mtDNA) polymorphisms were detected using 13 restriction enzymes on the total DNA obtained from blood samples of five Asian populations: Japanese and Ainu of northern Japan, Korean, Negrito (Aeta) of the Philippines, and Vedda of Sri Lanka. Of a total of 28 restriction-enzyme morphs detected, eight had not been reported previously. By combining the morphs, we were able to classify mtDNAs of 243 individuals into 20 mtDNA types. Phylogenetic analyses using maximum parsimony and genetic distance methods both showed that the Japanese, Ainu, and Korean populations were closely related to each other. Aeta was found to show a relatively close relationship to these three populations, confirming the conclusion from previous studies of blood markers. In contrast, Vedda was quite different from the other four populations.

Asia↗
PubMed1988

The genetic polymorphism of complement component C81 (alpha-gamma) in two Chinese populations.

The genetic polymorphism of the complement component C81 (alpha-gamma) in two Chinese populations (Beijing and Guangzhou) were investigated, using isoelectric focusing followed by an immunoblotting technique. Three common and two rare phenotypes were observed. The homozygote phenotype C81 A1 ascribed to a rare allele C81*A1 was newly detected. The frequencies calculated for the two common alleles were as follows: C81*A = 0.5674, C81*B = 0.4255 for the Beijing population; C81*A = 0.5117, C81*B = 0.4785 for the Guangzhou population. The gene frequencies of the two common alleles of C81 in both Chinese populations were similar to those for the other ethnic groups thus far reported, and there is no statistically significant difference between the Beijing and the Guangzhou populations.

Alleles↗