Biomedical subjects

S Utsunomiya

Publications and source records attributed to S Utsunomiya.

13 recordsLinked to original sources

PubMed2006

Structural stability and phase transitions in WO3 thin films.

Tungsten oxide (WO3) thin films have been produced by KrF excimer laser (lambda = 248 nm) ablation of bulk ceramic WO3 targets. The crystal structure, surface morphology, chemical composition, and structural stability of the WO3 thin films have been studied in detail. Characterization of freshly grown WO3 thin films has been performed using X-ray diffraction (XRD), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy (RS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) measurements. The results indicate that the freshly grown WO3 thin films are nearly stoichiometric and well crystallized as monoclinic WO3. The surface morphology of the resulting WO3 thin film has grains of approximately 60 nm in size with a root-mean-square (rms) surface roughness of 10 nm. The phase transformations in the WO3 thin films were investigated by annealing in the TEM column at 30-500 degrees C. The phase transitions in the WO3 thin films occur in sequence as the temperature is increased: monoclinic --> orthorhombic --> hexagonal. Distortion and tilting of the WO6 octahedra occurs with the phase transitions and significantly affects the electronic properties and, hence, the electrochemical device applications of WO3.

Journal Article↗

PubMed1999

The hypervariable region 1 protein of hepatitis C virus broadly reactive with sera of patients with chronic hepatitis C has a similar amino acid sequence with the consensus sequence.

Hypervariable region 1 (HVR1) proteins of hepatitis C virus (HCV) have been reported to react broadly with sera of patients with HCV infection. However, the variability of the broad reactivity of individual HVR1 proteins has not been elucidated. We assessed the reactivity of 25 different HVR1 proteins (genotype 1b) with sera of 81 patients with HCV infection (genotype 1b) by Western blot. HVR1 proteins reacted with 2-60 sera. The number of sera reactive with each HVR1 protein significantly correlated with the number of amino acid residues identical to the consensus sequence defined by Puntoriero et al. (G. Puntoriero, A. Lahm, S. Zucchelli, B. B. Ercole, R. Tafi, M. Penzzanera, M. U. Mondelli, R. Cortese, A. Tramontano, G. Galfre', and A. Nicosia. 1998. EMBO J. 17, 3521-3533. ) (r = 0.561, P < 0.005). The most widely reactive HVR1 protein, 12-22, had a sequence similar to the consensus sequence. The peptide with C-terminal 13-amino-acids sequence of HVR1 protein 12-22 (NH2-CSFTSLFTPGPSQK) was injected into rabbits as an immunogen. The rabbit immune sera reacted with 9 of 25 HVR1 proteins of genotype 1b including HVR1 protein 12-22 and with 3 of 12 proteins of genotype 2a. These results indicate that the HVR1 protein broadly reactive with patients' sera has a sequence similar to the consensus sequence, can induce broadly reactive sera, and could be one of the candidate immunogens in a prophylactic vaccine against HCV.

Amino Acid Sequence↗

PubMed1999

TT virus infection in hemodialysis patients.

OBJECTIVE: Recently, TT virus (TTV), associated with posttransfusion hepatitis, was discovered. Prevalence of TTV infection in maintenance hemodialysis (HD) units and its pathogenicity to liver was investigated. METHODS: A total of 115 patients on HD were assessed for presence of serum TTV. DNA was purified from sera, and nested polymerase chain reaction was done for the detection of TTV DNA. RESULTS: TTV was detected in 59 patients on HD (51.3%), as compared with healthy blood donors (15 of 91 [16.5%], p < 0.0001). Serum HCV RNA and HBs antigen were positive in 16 and three patients, respectively. The prevalence rate of TTV was already 58.3% in the patients on HD for only 1 yr, and did not change according to the duration of HD until 15 yr on HD. TTV was positive in 51.2% (43 of 84) of the patients with history of blood transfusion, and in 51.6% (16 of 31) of those without it. In HCV-negative patients, alanine aminotransferase (ALT) levels of TTV-positive patients were similar to those of TTV-negative patients. Contrarily, in HCV-positive patients, ALT levels were more frequently > or =15 IU/L in TTV-positive patients (14 of 18) than in TTV-negative patients (five of 15) (p < 0.05). CONCLUSIONS: TTV infection is remarkably prevalent in patients on HD and in healthy blood donors. It is suggested that TTV generally does not cause liver disease by itself, but there remains the possibility that TTV may aggravate liver disease caused by HCV.

Aged↗

PubMed1999

[The prevalence of TTV infection and the route of TTV transmission in hemodialysis patients--compared with HCV infection].

Recently a novel virus named TT virus (TTV), associated with posttransfusion hepatitis, was isolated. The prevalence of TTV infection and the route of TTV transmission in HD units was investigated. TTV was detected in 51.3% of patients on HD (59/115), as compared with 16.5% of healthy blood donors (15/91). The prevalence rate of TTV in the patients without history of blood transfusion was similarly high (51.6%), compared with that of those with history of blood transfusion (51.2%). The prevalence rate of TTV did not differ according to the duration of HD. These suggest that the risk of TTV infection is very high in HD units and there is another major route of TTV transmission than blood transfusion.

Biomarkers↗

PubMed1995

Automatic left ventricular volume measurements on contrast-enhanced ultrafast cine magnetic resonance imaging.

To assess the accuracy of automatic extraction of the left ventricular inner contour on contrast-enhanced ultrafast cine magnetic resonance (MR) images, we compared the values obtained by this method with those obtained using intravenous digital subtraction left ventriculography. High-quality single breath-hold contrast-enhanced ultrafast cine MR images were obtained in all cardiac phases on horizontal and vertical long axis sections of the left ventricle. For ultrafast cine MR imaging, a phase-rewind gradient-echo (rewind-SMASH) sequence was used. Automatic extraction of the left ventricular inner contour on contrast-enhanced ultrafast cine MR images was performed in all cardiac phases. High-quality left ventricular images of the horizontal long axis section were obtained in 127 of 160 patients (79%). The automatic extraction of the left ventricular contour was easily performed on high-quality images with very short processing time (4 s/frame). The values for left ventricular volumes obtained with the automatic extraction method on contrast-enhanced ultrafast cine MR imaging were correlated well with those obtained with the manual extraction method and IV-DSA in high quality cardiac images. The biplane modified Simpson's method using automatic extraction is an accurate and highly reproducible method for evaluating left ventricular volumes.

Cardiac Volume↗

PubMed1988