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Biomedical subjects

I Ueno

Publications and source records attributed to I Ueno.

At least 55 records · Page 3Linked to original sources
PubMed1994

Rat very-long-chain acyl-CoA dehydrogenase, a novel mitochondrial acyl-CoA dehydrogenase gene product, is a rate-limiting enzyme in long-chain fatty acid beta-oxidation system. cDNA and deduced amino acid sequence and distinct specificities of the cDNA-expressed protein.

cDNA encoding the precursor of rat very-long-chain acyl-CoA dehydrogenase (VLCAD) was cloned and sequenced. The longest cDNA insert had 2117 bases. This cDNA encodes the entire protein of 655 amino acids, including a 40-amino acid leader peptide and a 615-amino acid mature polypeptide. The identity of the VLCAD clone was confirmed by matching the amino acid sequence predicted from the cDNA to the NH2 terminus and seven internal proteolytic peptide sequences from purified rat liver VLCAD. The calculated molecular masses of the precursor protein, the mature protein, and the leader peptide are 70,961, 66,508, and 4,470 daltons, respectively. At the amino acid level, the significant homology to the other acyl-CoA dehydrogenases was found at the range from the 94th to the 473rd amino acid residue of the amino-terminal side. The catalytic residue and the residue lying near the dimethylbenzene side (si-side) of the flavin ring were speculated to be Glu-462 and Trp-249, respectively. The VLCAD cDNA was expressed in four kinds of hepatoma cells using a vaccinia virus expression system and was shown to encode the catalytically active enzyme. The cDNA expression in both rat hepatoma H4IIEC3 and McA-RH7777 enhanced about 3-fold mitochondrial beta-oxidation activity of long-chain fatty acids such as palmitic acid and stearic acid; hence, VLCAD is probably a rate-limiting enzyme in the long-chain fatty acid beta-oxidation system in these cell lines.

Acyl-CoA Dehydrogenase, Long-Chain↗
PubMed1994

Familial amyloid polyneuropathy in Taiwan: identification of transthyretin variant (Leu55-->Pro).

We report a family with familial amyloid polyneuropathy (FAP), showing an early-onset and a fatal outcome before age 30. Transthyretin (TTR) gene analysis showed one point mutation (T-->C change) in the second base of codon 55, and the corresponding amino acid substitution of proline (Pro) for leucine (Leu) was confirmed at the protein level. This is the first FAP family of Taiwanese origin demonstrating a causative gene abnormality, and FAP with TTR-Pro55 was considered to be more serious compared with other forms of FAP.

Adolescent↗
PubMed1994

Restriction fragment length polymorphism (RFLP) of genomic DNA of Moraxella (Branhamella) catarrhalis isolates in a hospital.

Epidemiological typing, based on restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (PFGE), was attempted for the 38 clinical isolates of Moraxella catarrhalis obtained at Shinshu University Hospital during the years 1987 and 1993. Digestion with SmaI or NotI generated well separable, 12 to 5 genomic DNA fragments ranging from 1,000 kb to 30 kb and the strains could be classified into 14 or 13 types, respectively. The electrophoretic profile differed with the strain in most of them and was hence useful to distinguish the each strain. Investigation for their RFLP have, however, suggested that majority of them, including the type strain ATCC25238, may have derived from a common ancestor.

Electrophoresis, Gel, Pulsed-Field↗
PubMed1993

[Determination of amantadine by pre-labeling with 3-(7'-methoxycoumarin-3'-carbonyl)-benzoxazoline-2-thione and high-performance liquid chromatography with fluorescence detection].

3-(7'-Methoxycoumarin-3'-carbonyl)-benzoxazoline-2-thione (MCBT) was synthesized as a precolumn fluorescent labeling reagent for amantadine for use in high-performance liquid chromatography (HPLC). Amantadine was derivatized quantitatively into a fluorescent compound through the amino group by treatment with MCBT at room temperature for 5 min in aqueous 95% acetonitrile solution in the presence of 4-dimethylaminopyridine. The derivative was subjected to HPLC on TSK gel ODS-80TM (250 x 4.6 mm i.d.) with methanol-water (10:1) as the mobile phase and monitored with an excitation wavelength of 355 nm and an emission wavelength of 405 nm. The limit of detection was 2.0 micrograms/ml in the urine. This method was satisfactory with respect to simplicity and precision to quantify amantadine spiked in the urine.

Amantadine↗
PubMed1993

Luteoskyrin, an anthraquinoid hepatotoxin, and ascorbic acid generate hydroxyl radical in vitro in the presence of a trace amount of ferrous iron.

Luteoskyrin is a bis-dihydroanthraquinone mycotoxin produced by Penicillium islandicum Sopp. By using EPR spin-trap techniques we investigated whether .OH is formed in a model system containing ascorbic acid and the toxin. In the presence of DMSO and DMPO, we found signals of DMPO-CH3, a more specific and reliable signature of .OH than DMPO-OH, together with the signals of ascorbyl radical. DMPO-CH3 signals increased with time of incubation up to 5.5 min. The DMPO-CH3 formation depended completely on both luteoskyrin and ascorbic acid, and deferoxamine, an iron-chelator, inhibited its formation. The signals disappeared in the presence of excess amount of catalase whereas SOD showed no effect. These results suggest that .OH is formed from ferrous ion present in the mixture of H2O2 generated from ascorbic acid and luteoskyrin.

Ascorbic Acid↗
PubMed1992

Nucleotide sequence of the human 70 kDa peroxisomal membrane protein: a member of ATP-binding cassette transporters.

The cDNA sequence of human liver 70 kDa peroxisomal membrane protein (hPMP70) was determined. The nucleotide sequence contains an open reading frame of 1977 base pairs and encodes an amino acid sequence of 659 residues which exhibits 95.0% identity with that of rat liver PMP70. hPMP70 shares close similarity to the members of a superfamily of ATP-binding transport proteins.

Amino Acid Sequence↗
PubMed1991

Characterization of neutrophil b-type cytochrome in situ by electron paramagnetic resonance spectroscopy.

Electron paramagnetic resonance spectroscopy at 4.2 K was successfully used to characterize neutrophil b-type cytochrome in situ. The spectra of resting neutrophils taken under aerobic conditions gave a set of characteristic signals in a high magnetic field (g = 2.85, 2.21 and 1.67) beside signals for myeloperoxidase and others. From the g values, shapes and the results of other experiments, these signals were attributed to those of cytochrome b558. The results indicate that cytochrome b558 in resting neutrophils is a hexa-coordinated ferric hemoprotein in a low-spin state. The obtained gz and gx values for the hemichrome were consistent with that of bis(imidazole)-coordinated hemoprotein.

Animals↗
PubMed1991

Detection of aflatoxin B1 in imported food products into Japan by enzyme-linked immunosorbent assay and high performance liquid chromatography.

In order to detect the presence of aflatoxin B1 (AFB1), the use of the enzyme-linked immunosorbent assay (ELISA) and recovery test was evaluated. The detection limit of ELISA for AFB1 was 1 pg/assay and the recovery from maize spiked with AFB1 exceeded 80%. AFB1 was detected by ELISA in seven out of twelve samples of imported food products including peanut, almond, red pepper, cocoa bean, black pepper, buckwheat, walnut, adlay, soybean, popcorn, and pistachio nut, and by high performance liquid chromatography (HPLC) in four of the samples. However, the content of AFB1 in these samples was less than 10 ng/g of the minimum value authorized by the Japanese sanitation law. These results demonstrate that ELISA is more sensitive than HPLC and imported food products are broadly contaminated with AFB1.

Aflatoxin B1↗
PubMed1989

Reevaluation of the spin-trapped adduct formed from 5,5-dimethyl-1-pyrroline-1-oxide during the respiratory burst in neutrophils.

By employing EPR spectrometry with the aid of a spin-trapping agent, 5,5-dimethyl-1-pyrroline-1-oxide (DMPO), the generation of superoxide anion and hydroxyl radical was reevaluated during the respiratory burst of porcine and human neutrophils. Properly prepared resting neutrophils did not generate any spin-trapped radical, and, when the cells were stimulated with phorbol myristate acetate, only DMPO-OOH, the spin-trapped adduct of superoxide anion, was detected. No formation of DMPO-OH, the spin-trapped adduct of the hydroxyl radical, was observed. DMPO-OOH was also detected principally when the neutrophils were stimulated with opsonized zymosan, a particulate stimulus. In the latter case, however, the formation of DMPO-OOH ceased shortly after the addition of zymosan and subsequent production of DMPO-OH was observed. The production of DMPO-OH was found to be associated with cell injury. DMPO at the concentration usually used for the experiment (0.045-0.09 M) injured phagocytizing neutrophils, causing lysis of the cells. On the other hand, an addition of cell homogenate or glutathione-glutathione peroxidase system to the suspension of intact cells which were producing DMPO-OOH resulted in the formation of DMPO-OH. Thus, DMPO-OH was probably derived from DMPO-OOH by the action of enzymes and/or factor(s) which were released from the lysed cells.

Animals↗
PubMed1988

Evaluation of immunoglobulin G preparations for anti-cytomegalovirus antibodies with reference to neutralizing antibody in the presence of complement.

Eighteen commercially available immunoglobulin G (IgG) preparations were evaluated by various methods for anti-cytomegalovirus (CMV) antibodies. The modifications of immunoglobulin G molecules, such as sulfonation, alkylation, and enzyme treatments, resulted in profound reductions in anti-CMV antibody titers. However, after reversion in vitro, sulfonated IgG preparations which have been shown to be reverted in vivo (Y. Masuho, K. Tomibe, K. Matsuzawa, T. Watanabe, S. Ishimoto, S. Tsunoda, and T. Noguchi, J. Biochem. 79:1377-1379, 1976) restored the anti-CMV antibody titers to levels comparable with those of nonsulfonated IgG preparations. There is no good correlation among the titers tested by different methods. As a method which reflects the biological activities in vivo, the neutralization test in the presence of complement is suitable for the evaluation of IgG preparations.

Antibodies, Viral↗
PubMed1984

Quantitative determination of the superoxide radicals in the xanthine oxidase reaction by measurement of the electron spin resonance signal of the superoxide radical spin adduct of 5,5-dimethyl-1-pyrroline-1-oxide.

Reactivities of biologically active compounds with superoxide radicals were examined by measurement of electron spin resonance (ESR) spectra of 5-hydroperoxy-2,2-dimethyl-1-pyrrolidinyloxyl formed from 5,5-dimethyl-1-pyrroline-1-oxide and the superoxide radicals generated by xanthine-xanthine oxidase system. Quantitative determination of the superoxide radicals was performed by comparing the intensity of the spin adducts with that of 4-hydroxy-2,2,6,6-tetramethyl-pipperidinooxyl whose spin concentration was determined. Methyl viologen enhanced the formation of this spin adducts, while, rutin and luteoskyrin prevented it.

Cyclic N-Oxides↗