Biomedical subjects

D Amano

Publications and source records attributed to D Amano.

11 recordsLinked to original sources

PubMed1999

Primary structure of rat spermidine synthase: an example of refining the cDNA-derived amino acid sequence.

The primary structure of rat spermidine synthase having the N-terminal acetylated methionine and 98.7% homology with that of the mouse enzyme is presented using a limited amount of the homogeneous enzyme. The study strategy was principally to compare the molecular masses of liberated peptides determined by three specific cleavage methods with those expected from known cDNA-derived amino acid sequences of mouse and human enzymes using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF-MS). The cleavage methods involved two enzymatic methods using lysylendopeptidase and arginylendopeptidase, and a chemical method for cleaving at the cysteine residue using 2-nitro-5-thiocyanobenzoic acid. Their usefulness was clearly demonstrated. Column-switching semimicro reversed-phase HPLC, which permits application of the entire reaction mixture, was useful for collecting a small amount of peptides containing the N-terminal amino acid, to confirm acetylation of the N-terminal methionine by MALDI TOF-MS. It was necessary in this approach to examine the amino acid sequence of certain peptides. The Edman method was used for the sequence analysis, and this will be replaced by an improved MALDI TOF-MS now available in a few laboratories.

Acetylation↗

PubMed1998

Ionspray ionization-mass spectrometric separation and determination of heptafluorobutyryl derivatives of polyamines.

We describe here an application of ionspray ionization-mass spectrometry (IS-MS) for simultaneous determination of putrescine, spermidine, and spermine without the need for coupling with other separation techniques such as high-performance liquid chromatography or capillary electrophoresis. Because it was essential to increase the mass of these compounds to eliminate contaminated low-mass ions, heptafluorobutyryl (HFB) derivatives were chosen. It was found that each HFB-polyamine appeared as a single major cation carrying an ammonium ion in a solution of 50% acetonitrile-water containing 0.5% ammonium acetate at an orifice potential of 20 V. Under these conditions, the three polyamines after addition of 15N-labeled polyamines as internal standards, followed by heptafluorobutylation, were determined simultaneously. It was shown, using a sample injection bulb set between the syringe drive and ionspray probe, that the analysis time for data acquisition was about 3 min and the sensitivity was about 10 fmol. In addition, polyamines in rat liver were determined by this method after simple fractionation with a small column of CM-cellulose with reasonable accuracy and precision. Behaviors of acetylated polyamines were also described, and the results showed that the acetylated polyamines would become additional target compounds in the present method.

Animals↗

PubMed1998

A practically zero horizontal magnetic field in a planar undulator used in the Tristan Super Light Facility.

The Tristan Main Ring (MR) at KEK (High Energy Accelerator Research Organization) has been used as a third-generation synchrotron radiation ring with an undulator installed in the MR as a third-generation light source. The magnetic field irregularities of the undulator were examined precisely. Measurement of the magnetic field after synchrotron radiation experiments showed that the magnetic irregularities in both the horizontal and vertical directions are negligibly small. This result suggests that our previous estimates of emittance, made using the measured undulator spectrum, should correctly represent the properties of the electron beam in the MR.

Journal Article↗

PubMed1998

Undulators at HiSOR - a compact racetrack-type ring.

A compact racetrack-type 700 MeV storage ring (HiSOR) has been constructed at Hiroshima Synchrotron Radiation Center (HSRC). As the ring was planned for synchrotron radiation research on science and technology using VUV to X-rays up to 5 keV with limited size and cost, the ring was designed (i) to realize a high magnetic field (2.7 T) using conventional dipole magnets for higher critical energy, and (ii) to include two straight sections for insertion devices. A linear undulator (25-300 eV) and a new-type helical/linear undulator were installed at the two straight sections. The latter undulator consists of upper and lower jaws, as in a planar undulator; each jaw consists of one fixed magnet array at the centre and two magnet arrays on both sides. By longitudinal displacement of the side magnet arrays, the phase between the vertical and horizontal magnetic fields, and therefore the polarization (right- or left-circular, elliptical, linear) can be selected. The helical/linear undulator gives almost perfect circular polarization at 4-40 eV in the helical configuration without changing the phase of the magnet arrays, as well as linearly polarized light at 3-300 eV in the linear configuration.

Journal Article↗

PubMed1993

Hypergalactosaemia in a patient with portal-hepatic venous and hepatic arterio-venous shunts detected by neonatal screening.

Hypergalactosaemia was discovered in a newborn girl during routine metabolic screening. Hereditary enzyme deficiency was ruled out. She had multiple hepatic haemangiomas with portal-hepatic venous and hepatic arterio-venous shunts. Since she showed signs of high-output heart failure due to the arterio-venous shunt, hepatic artery embolization was performed at age 3 months. A galactose tolerance test was performed before and after embolization and when the haemangioma no longer appeared on ultrasonography. Even after embolization, the level of blood galactose was abnormally elevated in the galactose tolerance test, but the blood galactose was eliminated more rapidly than before embolization. When the hepatic haemangioma was no longer detected by ultrasonography, the peak galactose level decreased. We surmise that the hypergalactosaemia was due to these shunts. In cases of hypergalactosaemia of unknown cause; liver haemangioma with portal-hepatic venous shunting should be considered as a possible cause. If a hepatic arterio-venous shunt also exists, this may contribute to the effect of the portosystemic shunting.

Arteriovenous Malformations↗

PubMed1978

Treatment of seven cases of chronic granulomatous disease with sulfamethoxazole-trimethoprim (SMX-TMP).

Seven male Japanese children with chronic granulomatous disease were given sulfamethoxazole-trimethoprim (SMX-TMP) for recurrent pyogenic infections, most of which had proved difficult to control with other antibiotics. With continous treatment the children remained free of infections severe enough to necessitate hospitalization, except on one occasion. Serious complications, including hematological disorders, never occurred during therapy and there were no changes in leukocyte function during therapy. These results indicate that SMX-TMP should be considered in the treatment of bacterial infections associated with chronic granulomatous disease.

Bacterial Infections↗

PubMed1976