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T Ueda

Publications and source records attributed to T Ueda.

At least 1,549 records · Page 86Linked to original sources

Interaction between xanthurenic acid-insulin complex and zinc ions.

An equimolar mixture of a xanthurenic acid-insulin complex and ZnSO4 was separated into an insulin peak and a peak containing xanthurenic acid (XA) and Zn by Sephadex G-75 column chromatograpy. XA and di-[L-histidino]-zinc (II) readily combined to produce di-[L-histidino]-di-xanthurenato zinc (II) (His2-Zn2+-XA2). By increase in the concentration of Zn2+ ions, XA was removed from di-[L-histidino]-di-xanthurenato zinc (II) (His2-Zn2+-XA2) as XA-Zn2+. The XA-insulin complex showed dcreased relative intensity of fluorescence compared with the Zn-insulin when excited at a wavelength of 284 nm. The difference spectrum between native Zn-insulin and XA-insulin complexes showed a slight red shift. A diffference in the CD spectrum between native Zn-insulin and XA-insulin complexes was observed.

Binding Sites↗

Cytochemical studies of acute tubular necrosis caused by simultaneous administration of dextran and kanamycin.

The increased nephrotoxicity of simultaneously administered kanamycin and low molecular weight dextran was studied in rats. The simultaneous administration of the two drugs showed an increase of nephrotoxicity, and caused pronounced vacuolation of the cytoplasm in the proximal tubular cells. The vacuoles were confirmed to be phagolysosomes by electron microscopic, histochemical and cell fractionation methods. The cell fractionation technique indicated that these phagolysosomes contained both kanamycin and dextran. The alteration of membrane was observed in the phagolysosomes, and these lysosomes of damaged renal tissue seemed to be more fragile than normal. The possible role played by lysosomes in the pathogenesis of acute tubular necrosis was discussed.

Acute Kidney Injury↗

Kinetic analysis of tumor regression during the course of radiotherapy.

A model of tumor regression during the course of radiotherapy is presented, which considered the lethal effect of radiation, the elimination of dying cells and the reproduction of surviving cells. The model was applied to multiple lung metastases in a woman, which were treated with different doses per fraction. The regression of tumor volume was measured from chest radiographs which were taken once a week during the treatment. Radiosensitivity of tumor cells estimated by the model was of D0=150 R and n=5. The half life of dying cells in the tumor was 15 days.

Cell Movement↗

Differences in properties of cytosol and membrane-derived protein kinases.

Adenosine 3':5'-monophosphate-dependent protein kinase present in membrane fractions of bovine brain, heart, liver, and muscle was solubilized with Triton X-100. Certain properties of the membrane-derived enzyme were compared with those of two adenosine 3':5'-monophosphate-dependent protein kinases present in the cytosol fractions from each of the same tissues. The properties studied included chromatographic behavior on DEAE-cellulose columns, specificity with respect to substrate proteins, and sensitivity to NaCl and Triton X-100. The membrane-derived enzyme from each tissue had properties similar to those of the membrane-derived enzyme from each of the other tissues. Moreover, the cytosol enzymes from each tissue had properties similar to those of the corresponding enzymes in the cytosol from each of the other tissues. However, for any given tissue, the properties of the membrane-derived enzyme differed from those of the cytosol enzymes, possibly reflecting different functional roles for the membrane-bound and cytosol enzymes.

Animals↗

Change in zeta potential and membrane potential of slime mold Physarum polycephalum in response to chemical stimuli.

Electrophoretic study of microplasmodia of the true slime mold Physarum polycephalum was carried out in the presence of various concentrations of inorganic salts, nucleotides and sugars, and the zeta potential at the surface of the plasmodia was determined from the electrophoretic mobilities. The membrane potential of the plasmodia was also measured under the same external conditions. It was shown that changes in the membrane potential induced by the chemical stimuli agreed approximately with those induced in the zeta potential in all cases examined. These results suggested that the phase boundary potential at the membrane-solution interface is mainly responsible for the membrane potential in the chemoreception of the slime mold.

Adenosine Triphosphate↗

A new synthesis of 5'-deoxy-8,5'-cyclo-adenosine and -inosine: conformationally-fixed purine nucleosides (nucleosides and nucleotides. XVI).

A versatile method for the synthesis of 5'-deoxy-8,5'-cycloadenosine, a conformationally-fixed "anti" type of adenosine, was presented. Irradiation of 2', 3'-O-isopropylidene-5'-deoxy-5'-phenylthioadenosine with 60W Hg vapor lamp afforded 2',3'-O-isopropylidene-5'-deoxy-8,5'-cycloadenosine in high yield. The use of other 5'-alkylthio derivatives also gave the cycloadenosine, though the yields were rather poor. Deacetonation of the cyclocompound with 0.1N HCl gave 5'-deoxy-8,5'-cycloadenosine. The cycloinosine derivative was similarly prepared. The nmr, mass and CD spectra of 5'-deoxy-8,5'-cycloadenosine were given and discussed with the previously reported results.

Adenosine↗