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Biomedical subjects

Y Nishida

Publications and source records attributed to Y Nishida.

At least 433 records · Page 24Linked to original sources
PubMed1984

A new method for the detection of Lesch-Nyhan heterozygotes by peripheral blood T cell culture using T cell growth factor.

Thioguanine-resistant T lymphoblast populations were selectively amplified using T cell growth factor in the cultures of peripheral blood T cells from four Lesch-Nyhan heterozygotes. Although Lesch-Nyhan T lymphoblasts were all thioguanine-resistant, none of the cultures from 13 control subjects yielded the growth of such defective cell populations. These data provide direct evidence for the existence of a small percentage (5%-40%) of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficient T cells in the heterozygotes, but not in normal individuals. Conversely, culture of the T lymphoblasts with azaserine plus hypoxanthine permitted the growth of the other part of the cell population that was enzyme positive. The low percentages of HGPRT-negative cells among T cells in heterozygotes suggest that the presence of this enzyme is beneficial for differentiation of lymphocytes of T cell linkage. Considering the ease and the reliability, culture of the peripheral T cells with thioguanine and T cell growth factor is very likely of practical use for detecting Lesch-Nyhan syndrome carriers among predisposed females.

Adolescent↗
PubMed1983

Molecular cloning and nucleotide sequencing of human immunoglobulin epsilon chain cDNA.

DNA complementary to mRNA of human immunoglobulin E heavy chain (epsilon chain) isolated and purified from U266 cells has been synthesized and inserted into the PstI site of pBR322 by G-C tailing. This recombinant plasmid was used to transform E. coli chi 1776 to screen 1445 tetracycline resistant colonies. Nine clones (pGETI - 9) containing cDNA coding for the human epsilon chain were recognized by colony hybridization and Southern blotting analysis with a nick-translated human IgE genome fragment. The nucleotide sequence of the longest cDNA contained in pGET2 was determined. The results indicate that the sequence of 1657 nucleotides codes for 494 amino acids covering a part of the variable region and all of the constant region of the human epsilon chain. Most of the amino acid sequence deduced from the nucleotide sequence is in substantial agreement with that reported. Furthermore a termination codon after the -COOH terminal amino acid marks the beginning of a 3' untranslated region of 125 nucleotides with a poly A tail. Taking this into account, the structure of the human epsilon chain mRNA, except a part of the 5' end, is conserved fairly well in the cDNA insert in pGET2.

Amino Acid Sequence↗
PubMed1983

Structure of the human immunoglobulin C epsilon 2 gene, a truncated pseudogene: implications for its evolutionary origin.

Cloning of the overlapping DNA fragments together with Southern hybridization experiments showed the organization of the human C epsilon and C alpha gene cluster as 5'-C epsilon 2-14 kilobases-C alpha 1----C epsilon 1-13 kilobases-C alpha 2-3'. Comparison of the nucleotide sequences of the C epsilon 1 and C epsilon 2 genes revealed that four deletions have taken place in the C epsilon 2 gene and its flanking regions. The three deleted regions in the 5' side of the C epsilon 2 gene are partially filled with shorter inserted sequences. One of them has removed the CH1 and CH2 exons and a portion of the epsilon switch (S epsilon) region. The S epsilon region and the CH4 exon still retain the functional structures, whereas the CH3 exon has been inactivated by deleting its 5' intervening sequence necessary for splicing. The tetranucleotide T-G-G-G (or T-G-G-C), which is usually found in close proximity of the class-switch recombination sites in mouse myelomas, is located 5' to the three deletion sites. The results imply that the mechanism responsible for the heavy chain class-switch recombination might be relevant to the evolutionary mechanism of creation of the truncated C epsilon 2 gene. The other deletion in the 3' flanking region of the C epsilon 2 gene may be due to slipped mispairing of the short direct repeat (C-C-C-C-C) at both ends.

Base Sequence↗
PubMed1983

Elevated erythrocyte phosphoribosylpyrophosphate and ATP concentrations in Japanese sumo wrestlers.

1. Japanese sumo wrestlers have a diet rich in energy, which results in marked obesity. Their plasma urate and triglyceride levels were significantly elevated. 2. Erythrocyte phosphoribosylpyrophosphate (PRPP) and ATP concentrations in sumo wrestlers were significantly elevated when compared to the levels in control subjects. 3. There were no significant differences in erythrocyte PRPP synthetase (EC 2.7.6.1), purine nucleoside phosphorylase (EC 2.4.2.1) and hypoxanthine guanine phosphoribosyl transferase (EC 2.4.2.8) activities between sumo wrestlers and control subjects. 4. Erythrocyte adenosine kinase (EC 2.7.1.20), adenosine deaminase (EC 3.5.4.4) and adenine phosphoribosyl transferase (EC 2.4.2.7) activities in sumo wrestlers were significantly elevated. 5. It seems that sumo wrestlers have an increased turnover of adenine nucleotides which may contribute to hyperuricaemia.

Adenine Nucleotides↗
PubMed1983

Congenital rubella syndrome: function of equilibrium of 80 cases with deafness.

The equilibrium function of 80 deaf children with congenital rubella syndrome, aged 12, was examined by the caloric and righting reflex tests. Of these 80 children, 24 (30%) had vestibular hypofunction, 6 (7.5%) were suspect, and the remaining 50 (62.5%) were normal. Of all 160 ears tested, vestibular hypofunction was proven in 21.3%, suspect in 5.6%, and normal in the rest. There was no correlation between the incidence of vestibular hypofunction and the degree of hearing loss. Of the 30 children with vestibular hypofunction, 14 (47%) showed a normal righting reflex, suggesting the working of a compensatory mechanism. Of the 50 children with normal caloric responses, 26% revealed an abnormal righting reflex. This discrepancy might be accounted for by an otolith organ injury or minimal brain dysfunction.

Caloric Tests↗
PubMed1983

The complete nucleotide sequence of the influenza virus neuraminidase gene of A/NJ/8/76 strain and its evolution by segmental duplication and deletion.

The neuraminidase (NA) gene from A/New Jersey (NJ)/8/76 (H1N1, formerly Hsw1 N1) strain isolated in 1976 was cloned into pBR322 and its complete nucleotide sequence was determined. The NJ8 NA gene is 1458 nucleotides long and the sequence predicted the primary structure of the NA molecule comprising of 469 amino acids with a molecular weight of 51,628. Comparison with other NA sequences of the N1 subtype strains which were isolated in 1933-1934 identified the highly variable regions at the amino-terminal stalk region and the carboxy-terminal regions. Potential glycosylation sites encoded by a 15 base-pair unit sequence are arrayed tandemly at the stalk regions. The lengths of stalk regions are highly variable because of segmental deletions in old NA genes. Possible mechanisms for such deletions are discussed.

Animals↗
PubMed1983

Production of plasminogen activator in a melanoma cell line.

A melanoma cell line (Bowes) was found to produce plasminogen activator even on its growing phase, and the rate of plasminogen activator production was rather constant. The production of plasminogen activator was proportional to the cell number. Morphologically, no specific features for plasminogen activator production were seen. Plasminogen activator was observed in the lysate of this cell line only when the cell number was large. The extracellular plasminogen activator activity was higher than the intracellular plasminogen activator activity, suggesting the existence of a secretion mechanism for the plasminogen activator.

Cell Count↗
PubMed1982

Long terminal repeat-like elements flank a human immunoglobulin epsilon pseudogene that lacks introns.

There are at least three immunoglobulin epsilon genes (C epsilon 1, C epsilon 2, and C epsilon 3) in the human genome. The nucleotide sequences of the expressed epsilon gene (C epsilon 1) and one (C epsilon 3) of the two epsilon pseudogenes were compared. The results show that the C epsilon 3 gene lacks the three intervening sequences entirely and has a 31-base A-rich sequence 16 bases 3' to the putative poly(A) addition signal, indicating that the C epsilon 3 gene is a processed gene. The C epsilon 3 gene sequence is homologous to the five separate DNA segments of the C epsilon 1 gene; namely, a segment in the 5'-flanking region (100 bases) and four exons, which are interrupted by a spacer region or intervening sequences. Long terminal repeat (LTR)-like sequences which contain TATAAA and AATAAA sequences as well as terminal inverted repeats are present in both 5'- and 3'-flanking regions. The 5' and 3' LTR-like sequences do not, however, constitute a direct repeat, unlike transposable elements of eukaryotes and retroviruses. The 3' LTR-like sequence is repetitive in the human genome, but is not homologous to the Alu family DNA. Models for the evolutionary origin of the processed gene flanked by the LTR-like sequences are discussed. The C epsilon 3 gene has a new open frame which codes potentially for an unknown protein of 292 amino acid residues.

Amino Acid Sequence↗
PubMed1982

Properties and activities of phosphoribomutase in the human leukemic cells.

1. The activities and properties of phosphoribomutase were determined in human leukemic leukocytes and normal polymorphonuclear leukocytes. 2. Leukemic leukocytes had markedly increased phosphoribomutase activity. 3. The Km value of leukemic cells to R-1-P was identical to normal cells. However, the Km value to glucose-1-6-diphosphate in leukemic cells had been shown to be low. 4. Inhibition rates by 2-3-DPG and Pi were lower in leukemic cells. 5. Leukemic cells enzyme was unstable by heating. 6. There were no significant differences in isoelectric points between normal cells and leukemic cells.

Chemical Phenomena↗
PubMed1982

Cloning of human immunoglobulin epsilon chain genes: evidence for multiple C epsilon genes.

An active human epsilon chain gene was cloned from a phage library containing partial EcoRI digests of IgE-producing myeloma DNA, using the human JH (joining) gene fragment as a probe. The epsilon chain gene clone was identified by partial nucleotide sequence determination. The germ-line constant region gene of the epsilon chain (C epsilon gene) was cloned from a human fetal liver DNA library, using the cloned epsilon chain gene as a probe. Comparative studies on the human and mouse germ-line epsilon chain genes revealed that the switch (S) sequence is more conserved than the coding sequence. Restriction endonuclease BamHI digestion of human DNA produced three C epsilon fragments of 3.0, 6.5, and 9.2 kilobases, which were named C epsilon 1, C epsilon 2, and C epsilon 3 genes, respectively. We found the three C epsilon gene fragments in all of the human DNA preparations from eleven individuals. The C epsilon gene expressed in the myeloma was identified as the C epsilon 1 gene. Because the C epsilon 2 gene is deleted from the myeloma DNA, the order of the C epsilon genes is likely to be 5'-C epsilon 2-C epsilon 1-C epsilon 3-3', assuming that all the C epsilon genes are on chromosome 14. The germ-line C epsilon 3 gene was also cloned from the myeloma DNA. Characterization of the C epsilon 3 gene revealed that it does not have the S region, suggesting that it might be a pseudogene.

Base Sequence↗
PubMed1982

Suppression by adenine compounds of histamine-induced contraction in isolated guinea pig tracheal rings.

The effects of purine compounds on the contraction of isolated guinea pig tracheal pigs induced by histamine were studied in vitro. Adenosine, at 0.1-1 mM concentrations, suppressed the contraction induced by histamine in the isolated guinea pig tracheal rings in a concentration-dependent manner. ATP, AMP and adenine were also effective in blocking tracheal constriction induced by histamine. The other purine compounds such as inosine, guanosine, guanine and hypoxanthine had no effect on tracheal smooth muscle. Coformycin, which is a competitive inhibitor of adenosine deaminase, did not potentiate adenosine action. Dipyridamole, which blocks adenosine uptake, did not impair the suppression caused by adenosine. These results suggest that adenosine action on tracheal smooth muscle cells may be mediated by direct action on cell surface receptors. In addition, it seems that adenosine is an important modulator of tracheal smooth muscle cell function.

Adenine↗
PubMed1982

Effect of urokinase on fibrinolysis and fibrinogenolysis.

The thrombolytic (fibrinolytic) effect of the urinary plasminogen activator, urokinase (UK), was compared with its fibrinogenolytic effect, using an artificial circulating system, and in in vivo pulmonary embolus and femoral vein thrombosis models. The thrombus lysing efficiency (fibrinolysis/fibrinogenolysis) was, in all cases, below 1.00, indicating that fibrinogenolysis is a primary function of UK while fibrinolysis is a secondary one.

Animals↗
PubMed1982

Effect of body lipid mass on red blood cell-and plasma-tocopherol levels.

A study on the relation of plasma- and RBC-tocopherol to plasma lipids and adiposity led to the following findings. Plasma tocopherol increased in parallel with increased plasma total lipid and beta-lipoprotein levels, while RBC tocopherol levels had little correlation with those of plasma lipids or beta-lipoproteins. The RBC-to-plasma tocopherol ratio decreased with increased plasma lipids and beta-lipoproteins. Though the relations of HDL-cholesterol, total lipids and beta-lipoproteins to RBC tocopherol levels resembled each other, those of HDL-cholesterol to plasma tocopherol levels and RBC-to-plasma tocopherol ratios differed greatly from the relationship in total lipids and beta-lipoproteins, especially the RBC-to-plasma ratios which had no definite pattern. Plasma tocopherol was unrelated to obesity grade, while the RBC tocopherol and RBC-to-plasma ratios decreased with increased obesity.

Adolescent↗