Biomedical subjects

J Ueda

Publications and source records attributed to J Ueda.

At least 73 records · Page 4Linked to original sources

PubMed1996

Detection of free radicals produced from reactions of lipid hydroperoxide model compounds with Cu(II) complexes by ESR spectroscopy.

Using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, alkoxyl radicals and peroxyl radicals produced from the reactions of tert-butyl hydroperoxide(tBuOOH) and cumene hydroperoxide (PhC(CH3)2OOH) with some copper(Cu)(II) complexes such as Cu(II) complexes of cimetidine (Cim), cyclo(L-histidyl-L-histidyl) (CyHH), L-histidylglycine (HG), and L-histidylglycylglycine (HGG) were detected by electron spin resonance (ESR) spectroscopy. However, Cu(II) complexes of glycyl-L-histidine (GH), glycyl-L-histidylglycine (GHG),glycylglycyl-L-histidine (GGH), and glycylglycyl-L-histidyl-glycine (GGHG) did not cause the generation of free radicals during the reaction with tert-butyl or cumene hydroperoxide. Addition of a biological reductant such as cysteine or glutathione to the system including these Cu(II) complexes and hydroperoxides gave tert-butoxyl and cumyl alkoxyl (RO.) radicals, respectively. These alkoxyl radicals underwent subsequent beta-scission reaction and generated the carbon-centered radical (R.). Although cysteine and glutathione are considered to be cellular antioxidants, our results suggest that these biological reductants facilitate Cu(II) complexes-dependent free radical generation.

Alcohols↗

PubMed1996

Glycylsarcosyl-L-histidylglycine, A peptide with a "breakpoint" in complex formation: hydrolysis of the complex [CuH-1L].

Coordination of CU(II) with glycylsarcosyl-L-histidylglycine to form the series of [CuL] and [CuH-1L] was studied potentiometrically and spectroscopically. [CuL] includes the Cu(N2O)O chromophore, in which Cu(II) coordinates with nitrogens from the terminal amino and imidazole groups and a carbonyl oxygen of the Gly-Sar bond, and shows a d-d transition band at 696 nm in the absorption spectrum and at 648 nm in the CD spectrum. The predominant species around pH 8 was [CuH-1L] with Cu(N3O) chromophore, in which Cu(II) coordinates with three nitrogens from a terminal amino, a deprotonated Sar-His peptide bond, and an imidazole of a histidyl residue, and shows the d-d transition band at 652 and 580 nm in the absorption and CD spectra, respectively. This species was hydrolyzed at the Gly-Sar peptide bond, yielding the Cu(II) complex of sarcosyl-L-histidylglycine.

Amino Acid Sequence↗

PubMed1996

Oxidation of spin-traps by chlorine dioxide (ClO2) radical in aqueous solutions: first ESR evidence of formation of new nitroxide radicals.

The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy. The ClO2 radical was generated from the redox reaction of Ti3+ with potassium chlorate (KClO3) in aqueous solutions. When one of the spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), was included in the Ti3+-KClO3 reaction system, ESR spectrum due to the ClO2 radical completely disappeared and a new ESR spectrum [aN(1) = 0.72 mT, aH(2) = 0.41 mT], which is different from that of DMPO-ClO2 adduct, was observed. The ESR parameters of this new ESR signal was identical to those of 5,5-dimethylpyrrolidone-(2)-oxyl-(1) (DMPOX), suggesting the radical species giving the new ESR spectrum is assignable to DMPOX. The similar ESR spectrum consisting of a triplet [aN(1) = 0.69 mT] was observed when the derivative of DMPO, 3,3,5,5-tetramethyl-1-pyrroline N-oxide (M4PO) was included in the Ti3+-KClO3 reaction system. This radical species is attributed to the oxidation product of M4PO, 3,3,5,5-tetramethylpyrrolidone-(2)-oxyl-(1) (M4POX). When another nitrone spin-trap, alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN) was used as a spin-trap, the ESR signal intensity due to the ClO2 radical decreased and a new ESR signal consisting of a triplet [aN(1) = 0.76 mT] was observed. The similar ESR spectrum was observed when N-t-butyl-alpha- nitrone (PBN) was used as a spin-trap. This ESR parameter [a(N)(1) = 0.85 mT] was identical to the oxidation product of PBN, PBNX. Thus, the new ESR signal observed from POBN may be assigned to the oxidation product of POBN, POBNX. These results suggest that the ClO2, radical does not form the stable spin adducts with nitrone spin-traps, but oxidizes these spin-traps to give the corresponding nitroxyl radicals. On the other hand, nitroso spin-traps, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS), and 2-methyl-2-nitrosopropane (MNP) did not trap the ClO2 radical. This result indicates that an unpaired electron of the ClO2 radical is localized on oxygen atom, because nitroso spin-traps cannot form the stable spin adduct with oxygen-centered radical.

Chlorates↗

PubMed1996

Elimination of iomeprol by hemodialysis.

Iomeprol is commercially a relatively new type of contrast medium. There have been no reports concerning its dialysability and safety when administered to patients with end-stage renal failure undergoing regular therapeutic hemodialysis (HD). One hundred milliliters of iomeprol (350 mgl/ml) was injected intravenously at computed tomography in 10 patients suffering from chronic renal failure. HD was then performed within 30 min after the start of iomeprol injection. The duration of HD was 4 h and blood samples were taken at 15, 30 min, 1, 2 and 4 h after its start. Mean dialysance of urea was 176.0-182.9 ml/min, compared to 131.4-133.3 ml/min for iomeprol. Elimination rate of iomeprol was 821.4 +/- 4.6% 4 h after the start of HD. Two of the 10 patients had side effects. One of them complained of a heat sensation and the other of sneezing and rash. As 4-h HD effectively removed iomeprol from the body and there were no severe side effects, it is concluded that iomeprol is suitable for HD patients.

Aged↗

PubMed1996

Effects of hypergravity on growth and cell wall properties of cress hypocotyls.

Elongation growth of etiolated hypocotyls of cress (Lepidium sativum L.) was suppressed when they were exposed to basipetal hypergravity at 35 x g and above. Acceleration at 135 x g caused a decrease in the mechanical extensibility and an increase in the minimum stress-relaxation time of the cell wall. Such changes in the mechanical properties of the cell wall were prominent in the lower regions of hypocotyls. The amounts of cell wall polysaccharides per unit length of hypocotyls increased under the hypergravity condition and, in particular, the increase in the amount of cellulose in the lower regions was conspicuous. Hypergravity did not influence the neutral sugar composition of either the pectin or the hemicellulose fraction. The amount of lignin was also increased by hypergravity treatment, although the level was low. The data suggest that hypergravity modifies the metabolism of cell wall components and thus makes the cell wall thick and rigid, thereby inhibiting elongation growth of cress hypocotyls. These changes may contribute to the plants' ability to sustain their structures against hypergravity.

Acceleration↗

PubMed1996

Elimination of low-osmolality contrast media by hemodialysis.

PURPOSE: To compare the dialyzability and safety of 2 types of low-osmolality contrast media administered to end-stage renal failure patients maintained on regular hemodialysis. MATERIAL AND METHODS: Of 44 CT examinations, iohexol was used in 22 and ioxaglate in the other 22. Adverse reactions and hemodynamic changes were recorded. Thirty minutes after the beginning of CT investigation, hemodialysis was commenced. Elimination rate and clearance of the contrast media were measured as indices of their dialyzability. RESULTS: After 4 hours of hemodialysis, 78.4+/-6.5% of iohexol and 72.4+/-6.0% ioxaglate were eliminated. Clearance of iohexol was higher than that of ioxaglate at all sampling times. No severe hemodynamic change nor adverse reaction were observed. Minor reactions were more frequently observed in the ioxaglate group. CONCLUSION: Iohexol, a nonionic monomeric contrast medium, is more advantageous for hemodialysis patients than ioxaglate, an ionic dimeric contrast medium.

Contrast Media↗

PubMed1996

Elimination of ioversol by hemodialysis.

PURPOSE: The dialysability of ioversol was investigated in 12 patients with chronic renal failure, on 4-h hemodialysis. MATERIAL AND METHODS: One hundred ml of ioversol (320 mg I/ml) was injected in less than 10 min during CT. Hemodialysis was commenced within 30 min of starting the contrast medium injection and was continued for 4 h. Blood was sampled before and at 15 min, 30 min, 1 h, 2 h, and 4 h after the start of hemodialysis. Mean dialysance of ioversol was 114 to 129 ml/min and the elimination rate was 82.5 +/- 5.1% 4 h after starting hemodialysis. The half-life of ioversol during hemodialysis was 1.80 +/- 0.38 h. The only side effects of the ioversol injection were heat sensations, which were experienced by 3 patients. RESULTS: As ioversol was effectively removed from the body during the 4 h of hemodialysis and no severe adverse reactions were observed, we conclude that ioversol is suitable for use in hemodialyzed patients.

Adult↗

PubMed1996

[A simultaneous determination of various main components in oriental pharmaceutical decoction "heii-san" by ion-pair high-performance liquid chromatography].

A simple and precise method was established for the simultaneous determination of five selected marker components in oriental pharmaceutical decoction "Heii-San" by means of high-performance liquid chromatography using tetra-n-amylammonium bromide (TAA) as an ion-pair reagent. For the separation of these five components, such as hesperidin (1), 6-gingerol (2), honokiol (3), glycyrrhizin (4) and magnolol (5), an ODS column was used with multi-step gradient elution with 10 mM TAA (H3PO4, pH 4.0)-acetonitrile. The acetonitrile content linearly increased from 25 to 90%. This method was compared with other three methods, i.e. a water-acetonitrile method, a phosphate buffer method and an ion-suppression method. Five main components were eluted within 50 min without interference from co-existing components.

Chromatography, High Pressure Liquid↗

PubMed1996

[A simultaneous determination of evodiamine and rutaecarpine in oriental pharmaceutical decoctions containing Evodia fruit by ion-pair high-performance liquid chromatography].

A simple and precise method was established for the simultaneous determination of evodiamine and rutaecarpine in oriental pharmaceutical decoctions containing Evodia Fruit using high-performance liquid chromatography with sodium dodecyl sulfate (SDS) as an ion-pair reagent. Evodiamine and rutaecarpine were eluted within 60 min without interference from co-existing components using an ODS column and a mixture of water-methanol-acetonitrile-SDS-phosphoric acid (600:330:70:5:0.01, v/v/v/w/v, pH 5.0) as a mobile phase.

Alkaloids↗

PubMed1996

Plant growth processes in Arabidopsis under microgravity conditions simulated by a clinostat.

The life cycle of Arabidopsis plants was examined by growing them on a horizontal clinostat. Seeds on agar media were allowed to germinate and seedlings were grown under a simulated microgravity on a horizontal clinostat. Clinorotation (3 rpm) did not appear to interfere with germination of plant seeds and development of cotyledons and leaves. Stress relaxation parameters of the cell wall, the minimum relaxation time and the relaxation rate did not appear to be affected by clinostat rotation. On the other hand, the length of inflorescences was reduced to 61-62% by clinostat rotation. Rotation was found to inhibit the polar transport of auxin, although inflorescence growth and auxin transport were not completely inhibited. From these facts, it is possible that the life cycle in Arabidopsis plants could be accomplished in space, although growth phenomena involving auxin transport and its action may be disturbed. Plants may have a capacity to grow in space and we may be able to cultivate crops in space.

Arabidopsis↗

PubMed1996

[The production of high sensitive anti-myeloperoxidase monoclonal antibodies and their sensitivity and specificity].

We produced anti-myeloperoxidase(MPO) monoclonal antibodies(moAb) to detect MPO sensitivity in leukemic cells by visual light microscopy. We got seven kinds of moAbs which showed different properties to MPO. These antibodies reacted to MPO in immature and mature neutrophils, monocytes and HL-60(human myeloid leukemic cell line) by immunochemical detection using the avidin-biotin complex(ABC) staining method, but the amounts of immune complex products were significantly different at each moAb. MPO2, MPO4, MPO9 and MPO13 moAbs blocked MPO activities but MPO5 showed no such inhibition. Most of the moAbs reacted to 59kD MPO moAb using the western blotting method, while MPO4 and MPO5 reacted to both 81kD and 89kD MPO precursors. This data suggests that these moAbs are useful to demonstrate a small amount of MPO in leukemic cells.

Antibodies, Monoclonal↗

PubMed1996

Gliomatosis cerebri: a case report.

Gliomatosis cerebri is a rare disease that thus far was usually diagnosed at the time of autopsy. In this communication we report the case of a young woman with gliomatosis cerebri. Diagnosis was established on the basis of characteristic imaging findings and typical histopathological features of surgical specimens obtained by craniotomy.

Adult↗

PubMed1996

Production of hydroxyl radicals by copper-containing metallothionein: roles as prooxidant.

Production of hydroxyl radicals by copper (Cu)-containing metallothionein (MT) and its relation to zinc (Zn) bound to MT were studied in vitro with reference to the mechanism of the Cu toxicity in the liver of LEC rats. Zn-MT prepared from the liver of Zn-injected rats was reacted with cupric ions at various Cu/Zn ratios, and the concentrations of the two metals bound to MT and in the solution, valence states of Cu in the solution, production of hydroxyl radicals were determined. Cupric ions replaced Zn in MT after being reduced by thiol groups, and MT, worked as an antioxidant. Cupric ions added to MT that did not contain Zn were reduced to cuprous ions by thiol groups in Cu-MT, and the Cu bound to MT was liberated in a form of cuprous ions. Hydroxyl radicals were produced in the presence of hydrogen peroxide in proportion to the amount of cuprous ions liberated from MT. Cu-containing MT was proposed to work as a prooxidant until all thiol groups in MT were oxidized when Zn was not present in MT. The results indicate that MT works as an antioxidant as long as Zn is present in Cu-containing MT, while it works as a prooxidant when Zn is not present by liberating 1.5 M equivalents of cuprous ions relative to cupric ions added, and hydroxyl radicals are produced in the presence of hydrogen peroxide. On the other hand, MT not bound by Cu does not work as a prooxidant throughout.

Animals↗

PubMed1996

Kimura disease: CT and MR findings.

The lesions of Kimura disease showed slightly high and very high intensity on T2-weighted MR, and low and intermediate intensity, respectively, on T1-weighted images. The degree of enhancement also differed between the two cases. These discrepancies may be attributable to differing degrees of fibrosis and vascular proliferation.

Adolescent↗

PubMed1995

Hepatic amyloidosis in Japan: histological and morphometric analysis based on amyloid proteins.

To investigate the relationship between the tissue distribution and the types of amyloid proteins, the detailed histopathologic features of the available liver in 284 cases of amyloidosis were examined. We classified hepatic amyloidosis into three types, namely, the vascular pattern, parenchymal pattern, and stromal pattern according to the topographic distribution pattern of amyloid. Of the 152 amyloid A (AA) cases, all but one exhibited the vascular pattern; the single exception had the parenchymal pattern. Among 117 amyloid light chain (AL) cases, 51.3% exhibited the vascular pattern and 43.6% the parenchymal pattern. The stromal pattern was observed in 5.1% of the cases but was found only in AL amyloidosis. The parenchymal and stromal patterns in the liver seemed to be characteristic morphological distributions of AL amyloidosis. Routine histochemical study is useful to distinguish AL from AA, although some ethnic differences were apparent. Morphometric results showed that the walls of the hepatic arteries with amyloid deposition were significantly thicker than walls in arteries from the control group. The arterial walls in AA amyloidosis, especially, were significantly thicker than walls in AL amyloidosis of any pattern.

Amyloid↗

PubMed1995

Reactions of copper(II)-oligopeptide complexes with hydrogen peroxide: effects of biological reductants.

Cu(II) complexes with oligopeptides containing histidyl residue in the second or third position could scarcely activate hydrogen peroxide (H2O2), but they could activate H2O2 to yield hydroxyl radical (.OH) in the presence of biological reductants such as cysteine and ascorbic acid. Further, DNA single strand breakage was also observed during the reactions of Cu(II)-glycylglycylhistidylglycine (GGHG) with H2O2 in the presence of same biological reductants.

Amino Acid Sequence↗

PubMed1995

Lung epithelial Na channel subunits are differentially regulated during development and by steroids.

Because the alpha-subunit of the rat lung epithelial Na channel (rENaC) is not expressed until late fetal gestation, the developmental immaturity of alpha-rENaC may be involved in the premature fetal lung's inability to mount a Na-absorptive response to appropriate agonists. As previous work has shown that the beta- and gamma-rENaC subunits of the Na channel are required for maximal alpha-rENaC activity, we determined their developmental expression in the fetal lung. In addition, because thyroid and corticosteroid therapy can mature the in vivo fetal lamb lung's ability to transport Na, we wished to determine whether such treatment increased the expression of alpha-, beta-, and gamma-rENaC. Lungs were harvested from normal rat fetuses of 17 through 22 days gestation (term = 22 days), normal rat pups during the first week of life, and adult rats. Initial expression of alpha-rENaC was detected at 19 days gestation and progressively increased in utero. beta- and gamma-rENaC mRNA were not detected until 21 and 22 days gestation, and then only at very low levels. During the first week after birth, the levels of alpha-rENaC declined, whereas beta- and gamma-rENaC mRNA levels increased. This pre- and postnatal pattern of alpha-rENaC expression correlates with the endogenous glucocorticosteroid levels in the fetus and the rat pup's early postnatal corticosteroid resistance. Combined or separate treatment of pregnant rats (16 through 22 days gestational age) with thyroid-releasing hormone (TRH) and/or dexamethasone (Dex) for 48 h showed that Dex, but not TRH, could increase fetal lung alpha-rENaC mRNA levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗

PubMed1995

Proton nuclear magnetic resonance studies of the complexation of zinc(II) with glycyl-L-histidylglycine.

The complexation of Zn(II) with glycyl-L-histidylglycine and its deuterated derivatives, glycyl-d2-L-histidylglycine and glycyl-L-histidylglycine-d2, was studied by proton nuclear magnetic resonance spectroscopy over the pD range, from 3.4 to 11.0, at 25 degrees C. Addition of Zn(II) to the peptide made the resonances of both imidazole C2-H and C4-H and both methylene-protons of glycyl residues at the amino-terminal and carboxylate end split to three lines in the pD range above 7.0. From the behavior of the C2-H and C4-H chemical shifts, formation of at least two species, in which the imidazole and amino nitrogens coordinated to the metal ion forming a chelate ring, was suggested. Those two species, the ratio of which varied depending on the total concentrations of complexes, seemed to be interconvertible; one referred to as B is a monomer and the other, referred to as C, may be a dimeric or polymeric complex.

Amino Acid Sequence↗