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Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 1,423 records · Page 79Linked to original sources
PubMed1990

1H-NMR study of heme propanoate mobility in the active site of myoglobin from Galeorhinus japonicus.

Time-dependent NOE studies of the C13(1) and C17(1) methylene proton resonances of the heme peripheral propanoate groups have elucidated their mobility in the active site of the ferric high-spin form of Galeorhinus japonicus myoglobin. A large difference in the chemical shift due to the non-equivalence of the heme C13(1) and C17(1) methylene proton resonances allows selective irradiation of a given proton resonance by a high-power selective decoupler pulse in spite of their fast relaxation rates. NOE accumulation of the resonance of one methylene proton after saturation of the resonance of the other proton essentially follows the theoretical prediction derived using the two-spin approximation, and the cross-relaxation rates for the heme C13(1) and C17(1) methylene proton spin systems were quantitatively determined. The correlation time for the mobility of the internuclear vector connecting the heme C13(1) or C17(1) methylene protons was then calculated from the cross-relaxation rate and values of approximately 11 ns were obtained for both C13(1) and C17(1) methylene groups in 2 mM Galeorhinus japonicus myoglobin at 35 degrees C. The immobile C13(1) and C17(1) methylenes of the heme propanoate groups, together with a large difference in chemical shift between the methylene proton resonances, dictate their fixed orientation with respect to the protein moiety as well as the heme plane, and are therefore consistent with the immobile heme in the active site of myoglobin.

Animals↗
PubMed1990

[Evaluation of multidisciplinary treatment involving chemotherapy with cis-diamminedichloroplatinum, bleomycin (peplomycin) and 5-fluorouracil for advanced esophageal carcinoma].

Twelve patients with unresectable squamous cell carcinoma of the esophagus were treated with a combination chemotherapy regimen consisting of cis-diamminedichloroplatinum (CDDP), bleomycin (BLM) or peplomycin (PEP), and 5-fluorouracil (5-FU). Ten of them received radiation therapy additionally. CDDP was administered once every 4 weeks at a dose of 50 mg/m2. Methylprednisolone of 250 mg was given intravenously 4 times at the same day with infusion of CDDP. BLM or PEP was administered intravenously at a dose of 20 mg/m2 every 2 weeks and 5-FU was administered at a dose of 330 mg/m2 on days 1-5, 15-19, and afterwards every 4 weeks. All patients received at least two courses of chemotherapy. All of them were evaluable. Complete and partial responses were obtained in one and eight cases, respectively. Responsive rate was 75.0%. The median duration of response was 17.0 weeks. The median duration of survival was 44.0 weeks in all patients, 46.1 weeks in responders and 17.9 weeks in non-responders. Nausea, vomiting, leucopenia, fever, nephrotoxicity and radiation esophagitis were observed as side effects but most of them were mild and well tolerated. In conclusion, this regimen was considered to be very useful as the chemotherapy for primary esophageal carcinoma.

Adult↗
PubMed1990

Purification of inactivated photoresponsive nitrile hydratase.

Photoresponsive nitrile hydratase from Rhodococcus sp. N-771 was purified in its inactivated form. The enzyme had a molecular weight of approximately 60 kDa and consisted of 2 subunits each having molecular weight of 27.5 and 28 kDa. The enzyme also contained 2 iron atoms/enzyme as a cofactor. The enzyme was more stable in its inactivated form, rather than the activated during storage in the dark. The enzyme was most stable in the temperature region of 0-35 degrees C, and lost its activity above 40 degrees C. The enzyme was most stable in the pH region of 6-8. The optimum temperature and pH for the enzyme activity was 30 degrees C and 7.8, respectively. The enzyme showed wide substrate specificity, and most of the metal ions did not affect enzyme activity significantly. The absorption spectrum revealed the presence of some cofactor which changed form after photoirradiation.

Enzyme Activation↗
PubMed1990

Increased urinary excretion of beta-hydroxyisovaleric acid in ketotic and non-ketotic type II diabetes mellitus.

To evaluate the catabolism of leucine in diabetes mellitus, the urinary excretion of beta-hydroxyisovaleric acid, a by-product of leucine catabolism, in 21 nonproteinuric type II diabetic patients with and without ketosis and 21 control subjects was measured using gas chromatography-mass spectrometry. Urinary beta-hydroxyisovaleric acid and serum leucine concentrations were higher in the 9 ketotic diabetic patients than in the 12 nonketotic diabetic patients (p less than 0.005, p less than 0.01, respectively) or in the control subjects (p less than 0.01, p less than 0.01, respectively). The serum leucine concentrations in the nonketotic diabetic patients and control subjects did not differ significantly (p greater than 0.05), but urinary beta-hydroxyisovaleric acid concentrations were significantly greater in the former (p less than 0.01). These data suggest that in type II diabetic patients the catabolism of leucine is accelerated even in the absence of ketosis and that the urinary beta-hydroxyisovaleric acid concentration is a useful marker of short-term metabolic control in these patients.

Adult↗
PubMed1990

Polypeptide composition of higher plant photosystem I complex. Identification of psaI, psaJ and psaK gene products.

High resolution gel electrophoresis of the native photosystem I complex retaining light-harvesting chlorophyll complex revealed the presence of three low-molecular-mass proteins of 7, 4.1 and 3.9 kDa in spinach, and 6.8, 4.4 and 4.1 kDa in pea, in addition to the other well-characterized higher-molecular-mass components. Upon further detergent treatment to deplete light-harvesting chlorophyll complex, the 7 kDa and 4.1 kDa proteins were removed from the photosystem I core complex of spinach, while the 3.9 kDa protein was retained. N-terminal sequencing demonstrated that the 4.1 kDa proteins from both spinach and pea correspond to the gene product of ORF42/44 in chloroplast genome of liverwort and higher plants, which was previously hypothesized as a photosystem I gene (psaJ) based on sequence homology with the cyanobacterial photosystem I component of 4.1 kDa [(1989) FEBS Lett. 253, 257-263]. N-terminal sequence of the spinach 3.9 kDa and pea 4.4 kDa proteins fitted with chloroplast ORF36/40 (psaI) although no homologue has been found in cyanobacteria. The spinach 7 kDa and pea 6.8 kDa proteins correspond to the nuclear-encoded psaK product and significantly matched with the N-terminal sequence of the cyanobacterial 6.5 kDa subunit. The evolutional conservation of the psaJ and psaK seems to suggest their intrinsic role(s) in photosystem I.

Amino Acid Sequence↗
PubMed1990

Strong interaction of lipopolysaccharides possessing the mannose homopolysaccharides with complement and its relation to adjuvant action.

LPS from Klebsiella pneumoniae O3 (KO3 LPS) exhibited an extremely high anticomplementary activity by the hemolysis assay using human sera. The free lipid A isolated from KO3 LPS by acid hydrolysis and R form LPS from a mutant lacking the O-specific polysaccharide portion possessed lower anticomplementary activity, and the O-specific polysaccharide fraction isolated from KO3 LPS alone did not activate the C system. It was suggested that the O-specific polysaccharide moiety enhanced the C activation by the lipid A portion. This was also supported by the finding that modification of the O-specific polysaccharide moiety with Con A or tyramine decreased anticomplementary activity of KO3 LPS, and that the other LPS preparations possessing the mannose homopolysaccharides as the O-specific polysaccharide portions such as KO3 LPS, such as LPS from Klebsiella O5, Escherichia coli O8 and O9, exhibited a high anticomplementary activity. KO3 LPS could activate the C system in either the classical or the alternative pathway, whereas the lipid A or R form LPS activated the classical pathway alone. The intensity of anticomplementary activity of LPS was parallel to that of their adjuvant action on antibody response to deaggregated BSA. The role of the anticomplementary activity in the expression of the adjuvant action of LPS is discussed.

Adjuvants, Immunologic↗
PubMed1990

Effects of replacement of tryptophan-140 by phenylalanine or glycine on the function of Escherichia coli aspartate aminotransferase.

Trp140 of E. coli aspartate aminotransferase has been converted to Phe or Gly by site-directed mutagenesis. As compared to the wild-type enzyme, either of the mutant enzymes showed 10- to 100-fold increase in Km's for natural dicarboxylic substrates, but did not show appreciable changes in Km's for aromatic substrates. Teh kcat values for dicarboxylic and aromatic substrates were greatly decreased by [Trp140----Gly] mutation, but were decreased to lesser extents by [Trp140----Phe] mutation. These findings suggested that N(1) of Trp140 may not be essential for catalysis, but may be partly involved in the binding of the distal carboxylate group of the dicarboxylic substrates.

Aspartate Aminotransferases↗
PubMed1990

Herpes simplex virus glycoprotein D. Protective immunity against murine herpetic keratitis.

%$%%protective effect of glycoprotein D (gD) immunization against murine herpetic keratitis was investigated. gD was purified by affinity chromatography using anti-gD monoclonal antibodies. Prior immunization with gD was shown to be effective in protecting mice from both the development of stromal keratitis and the spread of the virus to the central nervous system. The level of serum antibodies for virus neutralization, as well as for complement-dependent cytolysis (CDC), was significantly elevated in gD-immunized animals. Cellular immunity, however, was not detected. These results indicate that two antibody-mediated defense mechanisms--virus neutralization and CDC--were responsible for the protective effect observed in our study.

Animals↗
PubMed1990

Mechanism of photoinhibition in vivo. A reversible light-induced conformational change of reaction center II is related to an irreversible modification of the D1 protein.

The light-induced inactivation of the photochemical reaction center II (RCII) of oxygenic chloroplasts (photoinhibition) was investigated in cells and isolated thylakoids of the green alga Chlamydomonas reinhardtii. The process is resolved into a reversible conformational change followed by an irreversible modification of RCII D1 protein. The light-induced changes in vivo persisted in isolated thylakoids. The first step is characterized by (i) destabilization of the secondary acceptor semiquinone anion, Q-B, bound to the D1 protein. This is demonstrated by a reduction in the activation energy of S2,3Q-B charge recombination as measured by the thermoluminescence technique; and (ii) a rise in the intrinsic fluorescence and a decrease of the maximal fluorescence. Unoccupancy of the QB site by plastoquinone partially protected RCII against the light-induced destabilization of Q-B. The extent of charge separation (P+680Q-A) was not affected. However, the slow phase (microsecond) of P+680 dark reduction increased, and the amplitude of signal II was reduced by 20-30%, indicating that in a fraction of RCII, electron donation from Z to P+680 was impaired without losing primary photochemistry. This modification correlates with the irreversible change in D1 protein resulting in the formation of a trypsin-resistant fragment of 16 kDa detected in D1 isolated from light-exposed cells. The change in the Q-B stability could allow charge equilibration with QA and thus explain the rise in the intrinsic fluorescence level and reduction of electron flow to plastoquinone. The change in the lifetime of P+680 can account for further reduction in electron flow (photo-inhibition). The irreversible light-dependent modification of D1 may serve as the signal for its degradation and replacement by a newly synthesized molecule (turnover).

Chlamydomonas↗
PubMed1990

Conformational equilibria of the L-iduronate residue in non-sulphated di-, tetra- and hexa-saccharides and their alditols derived from dermatan sulphate.

The conformation of the L-iduronate residue in non-sulphated di-, tetra- and hexa-saccharides and their alditol derivatives derived from rooster comb dermatan sulphate was investigated by 400 MHz 1H-n.m.r. spectroscopy. The ratio of conformational isomers is obtained by the average spin-spin coupling constants of a mixture of nearly isoenergetic conformers (1C4, 4C1 and 2S0). The non-reducing terminal L-iduronate residue in the tetrasaccharides (I-H-I-H and I-H-G-H) and their alditols (I-H-I-H-ol and I-H-G-H-ol) is in equilibrium with three conformers (1C4, 30%; 4C1, 40%; 2S0, 30%) of nearly equal population. Whereas the internal L-iduronate residue in the tetrasaccharides (I-H-I-H and G-H-I-H) exists as an equilibrium mixture of 1C4 (54%) and 2S0 (42-44%) conformers, that of their alditols (I-H-I-H-ol and G-H-I-H-ol) is in equilibrium between 2S0 conformer (66%) and 1C4 conformer (28%). The conformational population for the internal L-iduronate residue 2I in the hexasaccharide (3I-H-2I-H-1I-H) is also calculated and compared with that for the L-iduronate residue in native dermatan sulphate, which was calculated on the basis of the spin-spin coupling constants reported by Gatti, Casu, Torri & Vercellotti [(1979) Carbohydr. Res. 68, c3-c7].

Animals↗
PubMed1990

Organization and primary sequence of multiple genes coding for the apopolysialoglycoproteins of rainbow trout.

We have shown that the mRNAs for apopolysialoglycoproteins (apoPSGP) of rainbow trout contain various numbers of a repetitive sequence of 39 base-pairs encoding mature apoPSGP, and that this sequence is bordered by highly homologous 5' and 3' regions encoding pre-, pro- and telopeptides. These mRNAs are thought to be transcribed from different genes that constitute a large multiple gene family (more than 100 members). Here, we have determined the structures of several members of the apoPSGP gene family. The results show that two of three genomic DNA fragments contain two independent apoPSGP genes in the same orientation with unrelated sequences intervening. Five characterized genes have essentially the same organization and sequence. Each gene has four exons, and CAAT and TATA sequences were found in the 5'-flanking regions. However, two noteworthy differences were observed among the five genes; a diversity in the number of the 39 base-pair repeats, also observed among the cDNA clones, and a one-base polymorphism in the 39 base-pair repeat, which causes an amino acid change. This polymorphism was not detected among the cDNA clones obtained. The boundary positions of the genes are various and contain no transposon-like structures. The variation in the number of repeats and the absence of a rule for bordering positions of the genes suggest that apoPSGP genes may have been amplified by gene duplications, unequal recombination, and selection of chromosomes having larger numbers of apoPSGP genes.

Amino Acid Sequence↗
PubMed1990

Mass spectrometric identification of 2-hydroxydodecanedioic acid and its homologues in urine from patients with hopantenate therapy during clinical episode.

Urine from patients with calcium-4-(2,4-dihydroxy-3,3-dimethylbutyramido) butyrate hemihydrate (hopantenate) therapy during episodes of Reye's-like syndrome was found to contain a number of unusual dicarboxylic acids in high concentrations; odd- and even-numbered medium-chain dicarboxylic acids, alpha-hydroxydicarboxylic acids and beta-hydroxydicarboxylic acids. The abnormal excretion of dicarboxylic acids, alpha- and beta-hydroxydicarboxylic acids disappeared after discontinuance of hopantenate therapy. Besides the excretion of 2-hydroxydecandedioic acid, which has been previously described in Zellweger syndrome or neonatal adrenoleukodystrophy, a series of alpha-hydroxydicarboxylic acids was detected and identified. In this paper, we have characterized some new compounds by gas chromatography/mass spectrometry: 2-hydroxydodecanedioic acid, 2-hydroxydodecenedioic acid, 2-hydroxytetradecanedioic acid, 2-hydroxytetradecenedioic acid and 2-hydroxyoctanedioic acid.

Aged↗
PubMed1990

Inhibitory actions of diltiazem and its derivative, TA3090 on the Ba-current recorded from smooth muscle cells of the rabbit mesenteric artery.

The effects of diltiazem and its derivative, TA3090 on the Ba-induced inward current were investigated using dispersed smooth muscle cells of the rabbit mesenteric artery. Diltiazem and TA3090 inhibited the inward current, in a concentration-dependent manner, and TA3090 was more potent than diltiazem (IC50 for diltiazem was 300 mumol/l and for TA3090, 30 mumol/l). The inward current completely recovered from the inhibitory actions of diltiazem (100 mumol/l) after its removal at holding potentials of -60 and -40 mV, though complete recovery did not occur after TA3090 (1-100 mumol/l). The voltage-dependent inactivation curves were shifted to the left by both drugs. Judging from the amplitudes of shift of V-half, the dissociation constants of inhibition for both diltiazem and TA3090 in the inactivated state were 17 mumol/l and 2.6 mumol/l, respectively. At a holding potential of -60 mV, diltiazem and TA3090 reduced the peak amplitude of the inward current, and diltiazem, but not TA3090, accelerated the decay of the current (300 ms command pulse duration). However, TA3090 did accelerate the decay of the current when a longer pulse (1 s) was applied, or when a depolarizing pulse was applied from a holding potential of -80 mV. Changes in the pH (range 6.8-7.7) of the bathing solution did not influence the decay of the current. In conclusion, TA3090 inhibits the Ca-channels of smooth muscle cells of the rabbit mesenteric artery, in a voltage-dependent manner, and its inhibitory actions are similar to those of diltiazem. However, TA3090 has much longer and stronger inhibitory actions on the Ba-inward current than diltiazem.

Animals↗
PubMed1990

Prebiotic synthesis of orotic acid parallel to the biosynthetic pathway.

By heating an aqueous solution of aspartic acid and urea, carbamylaspartic acid is first formed and then the molecule is cyclized to dihydroorotic acid (DHO) with loss of water. Irradiation of an aqueous solution of DHO with a tungsten lamp yields orotic acid by photo-dehydrogenation of the molecule. This pathway of orotic acid formation is quite similar to that of biosynthesis of the molecule.

Aspartic Acid↗
PubMed1990

Mechanisms of endothelin-induced augmentation of the electrical and mechanical activity in rat portal vein.

Actions of porcine endothelin (ET) on the electrical and mechanical activity of the rat portal vein were investigated by means of the intracellular microelectrode and isometric tension recording techniques, ET (greater than 0.1 nM) enhanced the amplitude and frequency of the spontaneous contractions which ceased in the presence of 100 nM dihydropyridine derivatives (nifedipine or nicardipine). ET (0.15 nM) increased the frequency of the spontaneous action potentials, with no change in the basal membrane potential. Higher concentrations of ET (greater than or equal to 0.3 nM) further depolarized the membrane potential and increased the spike frequency. After blocking the spontaneous action potentials with nifedipine (100 nM), ET still depolarized the membrane. The depolarization was associated with a reduction in the electrotonic potential and was blocked in a Na-deficient solution (15.5 mM) but not in Ca-free, K-deficient or Cl-deficient solutions. In a Na-deficient solution, ET still evoked action potentials without depolarization. In Ca-free solution, ET depolarized the membrane potential with small oscillations, which were blocked by nifedipine (100 nM). The results indicate that in the rat portal vein, ET enhances electrical and mechanical responses through activation of the dihydropyridine-sensitive and voltage-dependent Ca channels. Acceleration of the Ca entry induced by ET can occur with or without depolarization of the membrane and can enhance the pacemaking mechanism.

Animals↗
PubMed1990

Cisplatin, ifosfamide and vindesine in the chemotherapy of non-small-cell lung cancer: a combination phase II study.

A total of 47 patients with unresectable non-small-cell lung cancer were treated with a regimen consisting of cisplatin (CDDP, 100 mg/m2), ifosfamide (IFX, 2 g/m2 x 3; with mesna) and vindesine (VDS, 3 mg/m2) (CIV). This regimen was given over a 3- or 5-week period. Among 40 completely evaluable patients, 19 partial responses (PRs) were observed, for a response rate of 47.5% (78.6% in squamous-cell carcinoma and 30.1% in adeno- and large-cell carcinoma); no complete responses (CRs) were obtained. The hematologic toxicity was not severe, but the renal toxicity was rather high; two patients developed acute renal failure and died of subsequent pancytopenia and sepsis. We concluded that the CIV regimen was more effective, especially against squamous-cell carcinoma, but more toxic than the combination of CDDP and VDS for non-small-cell lung cancer and that candidates for this therapy must be carefully chosen.

Acute Kidney Injury↗