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Biomedical subjects

Y Asano

Publications and source records attributed to Y Asano.

At least 145 records · Page 8Linked to original sources
PubMed2001

Observation of B --> J/psi K(1)(1270).

We report the first observation of the exclusive decay process B-->J/psi K(1)(1270) using a sample of 11.2M BB macro meson pairs collected in the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. We measure branching fractions of B[B(0)-->J/psi K(0)(1)(1270)] = (1.30+/-0.34+/-0.32) x 10(-3) and B[B(+)-->J/psi K(+)(1)(1270)] = (1.80+/-0.34+/-0.39) x 10(-3), where the first error is statistical and the second is systematic. These modes constitute approximately 15% of the total number of B-->J/psi X decays. No evidence is seen for B-->J/psi K(1)(1400) and we set an upper limit for this branching fraction.

Journal Article↗
PubMed2001

Observation of Cabibbo suppressed B --> D(*)K- decays at Belle.

We report observations of the Cabibbo suppressed decays B-->D((*))K- using a 10.4 fb(-1) data sample accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. We find that the ratios of Cabibbo suppressed to Cabibbo favored branching fractions are B(B--->D0K-)/B(B--->D0pi(-)) = 0.079+/-0.009+/-0.006, B(B(0)-->D+K-)/B(B(0)-->D+pi(-)) = 0.068+/-0.015+/-0.007, B(B--->D(*0)K-)/B(B--->D(*0)pi(-)) = 0.078+/-0.019+/-0.009, and B(B(0)-->D(*+)K-)/B(B(0)-->D(*+)pi(-)) = 0.074+/-0.015+/-0.006. These are the first observations of the B-->D+K-, D(*0)K-, and D(*+)K- decay processes.

Journal Article↗
PubMed2001

Observation of large CP violation in the neutral B meson system.

We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.

Journal Article↗
PubMed2001

Down-regulation of IL-12 p40 gene in Plasmodium berghei-infected mice.

We analyzed the mechanism that causes suppression of IL-12 p40 gene induction during Plasmodium berghei infection. Although IL-12 together with IFN-gamma plays an important role in protection against pathogenic infection, the IL-12 p70 protein production of infected macrophages is lower than that by the uninfected macrophages. We showed in the present study that the induction of IL-12 p40 gene but not IL-12 p35 gene in macrophages of P. berghei-infected mice was profoundly inhibited. The inhibition was induced by interaction with macrophages that had contacted with P. berghei-infected erythrocytes and was mediated by a soluble factor, IL-10. There was comparable activation of NF-kappaB in uninfected and infected cells. The induction of IFN-regulatory factor-1 gene was comparable in transcription level in uninfected and infected cells, while the unidentified complex formation of IFN-regulatory factor-1 was observed in infected cells. Therefore, the inhibition of the IL-12 p40 gene induction appeared to be regulated at transcriptional regulation level of the gene.

Animals↗
PubMed2001

Efficient preparation of (R)-alpha-monobenzoyl glycerol by lipase catalyzed asymmetric esterification: optimization and operation in packed bed reactor.

Optically active (R)-alpha-monobenzoyl glycerol (MBG) was synthesized by Candida antarctica lipase B (CHIRAZYME L-2) catalyzed asymmetric esterification of glycerol with benzoic anhydride in organic solvents. Various conditions, such as the type and composition of the organic solvent, water content of the system, reaction temperature, and concentrations of the substrates were systematically examined and optimized in screw-capped test tubes with respect to both the reaction rate and the enzyme selectivity. 1,4-Dioxane was found to be the best solvent and no additional water was needed for the system. The optimum temperature was around 30 degrees C, while the most suitable substrate concentrations were 100 mM each for glycerol and benzoic anhydride, respectively. However, when excessive anhydride (e.g., 200 mM) was used, the produced MBG could be further transformed into 1,3-dibenzoyl glycerol (DBG) by the same enzyme with a priority to (S)-MBG, resulting in a significant improvement of the product optical purity from ca. 50-70% e.e. Under optimal conditions (100 mM glycerol, 100-200 mM benzoic anhydride, dioxane, 25-30 degrees C), the enzymatic synthesis of (R)-MBG was successfully operated in a packed-bed reactor for about 1 week, with an average productivity of 0.79 g MBG/day/g biocatalyst in the case of continuous operation and 0.94 g MBG/day/g biocatalyst in the case of semicontinuous operation. After refinement and preferential crystallization of the crude product, (R)-MBG could be obtained in an almost optically pure form (>98% e.e.).

Benzoates↗
PubMed2001

Long-term persistence of cellular immunity to Oka vaccine virus induced by pernasal co-administration with Escherichia coli enterotoxin in mice.

A mutant of Escherichia coli enterotoxin induced cellular immunity to a live varicella vaccine (the Oka strain) as a mucosal adjuvant in mice. The persistence of this cellular immunity was investigated. A commercially available live Oka vaccine virus and toxin were administered once simultaneously via the nasal route, in mice. Ten or 12 months later, a delayed-type hypersensitivity to the vaccine virus was detected by footpad test, but an antibody neutralizing the varicella-zoster virus was not. When spleen cells from mice immunized with the vaccine and toxin were re-stimulated by live vaccine in vitro, their thymidine uptake and IL-2 production were higher than those from mice immunized with the vaccine alone, but lower than those of spleen cells prepared from mice 2 months after nasal administration. Production of IL-4 in these cells, however, was not induced by re-stimulation in vitro. These results suggest that although humoral immunity for Oka vaccine virus is only weakly induced by one co-administration of the vaccine and toxin, cellular immunity is induced and maintained over 1 year, though it declines with age. The nasal administration of the vaccine and toxin might be effective for maintaining cellular immunity to the varicella-zoster virus long term.

Administration, Intranasal↗
PubMed2001

Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S).

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.

Journal Article↗
PubMed2001

Molecular cloning of human squamous cell carcinoma antigen 1 gene and characterization of its promoter.

The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes, SCCA1 and SCCA2, which are 95% identical in nucleotide sequence. SCCA1 is a papain-like cysteine proteinase inhibitor, while SCCA2 is a chymotrypsin-like serine proteinase inhibitor. We analyzed here the sequence and the promoter activity of the 5'-flanking region of the SCCA1 gene. Deletion analysis of SCCA1 and SCCA2 promoter identified a 471-bp core promoter region upstream of the transcription start site. The transcriptional activity of SCCA1 promoter was up-regulated in squamous cell carcinoma cells, compared with keratinocyte and adenocarcinoma cells. The ratios of SCCA1 to SCCA2 promoter activity in squamous cell carcinoma, keratinocyte and adenocarcinoma cells were respectively 1.6, 5.3 and 2.8. Position -50 of SCCA1 and SCCA2 promoters played an important role in determining the promoter activities of SCCA1 and SCCA2. These findings suggest that the transcriptional regulation of SCCA1 and SCCA2 might differ among squamous cell carcinoma, keratinocyte and adenocarcinoma cells, and that SCCA1 promoter might be a potential target of gene therapy for squamous cell carcinoma.

Antigens, Neoplasm↗
PubMed2001

Measurement of the CP violation parameter sin2 phi(1) in B(0)(d) meson decays.

We present a measurement of the standard model CP violation parameter sin2 phi(1) (also known as sin2beta) based on a 10.5 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psiK(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psiK(L), or J/psipi(0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin2 phi(1) = 0.58(+0.32)(-0.34)(stat)+0.09-0.10(syst).

Journal Article↗
PubMed2001

Detection of truncated midkine in Wilms' tumor by a monoclonal antibody against human recombinant truncated midkine.

Although the expression of a truncated midkine (tMK) mRNA has been detected in many cancer cells, the tMK protein itself has not yet been identified. The expression, purification and characterization of human recombinant tMK were described in the former report. A mouse hybridoma cell line producing an IgG2b monoclonal antibody (mab) against purified recombinant tMK was established. This anti-tMK mab did not cross react with synthetic full length (or c-half) human midkine. A putative native tMK was identified in G401 cells using this mab, and showed the same apparent Mw as the recombinant tMK in SDS-PAGE. This mab was also used in an immunohistochemical study to evaluate the expression of tMK in Wilms' tumor cell line, G401 cells, as well as in Wilms' tumor patient specimens. G401 cells and all Wilms' tumor patient specimens immunoreacted with this anti-tMK mab. We conclude that Wilms' tumor cells express tMK and that this mab is useful for the detection of tMK in the Wilms' tumor.

Antibodies, Monoclonal↗
PubMed2001

Clinical significance of surfactant protein D as a serum marker for evaluating pulmonary fibrosis in patients with systemic sclerosis.

OBJECTIVE: To determine the clinical significance of surfactant protein D (SP-D), a useful marker for evaluating various lung diseases, in patients with systemic sclerosis (SSc) and to clarify any clinical significance between SP-D and KL-6, which is known to be correlated with pulmonary fibrosis (PF) in SSc patients. METHODS: We used a specific enzyme-linked immunosorbent assay to measure serum SP-D levels in 83 patients with SSc and 31 healthy control subjects. RESULTS: The serum levels of SP-D were significantly higher in patients with SSc than in healthy controls (mean +/- SD 81.9+/-59.2 versus 34.8+/-13.7 ng/ml). Serum SP-D levels in patients with diffuse cutaneous SSc were significantly higher than those in patients with limited cutaneous SSc (98.8+/-72.1 versus 66.8+/-40.0 ng/ml). Serum SP-D levels in patients with PF were significantly elevated compared with those in patients without PF (99.7+/-64.1 versus 65.3+/-49.4 ng/ml). Moreover, the incidences of decreased percentage diffusing capacity for carbon monoxide and decreased percentage vital capacity were also significantly greater in patients with elevated SP-D levels than in those with normal levels (67% versus 43% and 36% versus 17%, respectively). There was a significant positive correlation between serum levels of SP-D and KL-6. Serum SP-D and KL-6 levels showed almost the same sensitivities and specificities in the diagnosis of PF (68% versus 73% and 70% versus 74%, respectively). These two markers also predicted PF to almost the same degree (31% versus 33%, respectively). CONCLUSION: These results suggest that SP-D, as well as KL-6, may be a useful serum marker for evaluating PF in patients with SSc.

Antibodies, Antinuclear↗
PubMed2001

Calyculin-A, an inhibitor for protein phosphatases, induces cortical contraction in unfertilized sea urchin eggs.

When an unfertilized sea urchin egg was exposed to calyculin-A (CL-A), an inhibitor of protein phosphatases, for a short period and then lysed, the cortex contracted to exclude cytoplasm and became a cup-shaped mass. We call the contracted cortex "actin cup" since actin filaments were major structural components. Electron microscopic observation revealed that the cup consisted of inner electron-dense layer, middle microfilamentous layer, and outermost granular region. Microfilaments were heavily accumulated in the inner electron-dense layer. The middle layer also contained numerous microfilaments, which were determined to be actin filaments by myosin S1 decoration, and they were aligned so that their barbed ends directed toward the outermost region. Myosin II, Arp2, Arp3, and spectrin were concentrated in the actin cup. Immuno-electron microscopy revealed that myosin II was localized to the electron-dense layer. We further found that the cortical tension of the egg increased just after application of CL-A and reached maximum within 10 min. Cytochalasin B or butanedione monoxime blocked the contraction, which suggested that both actin filaments and myosin ATPase activity were required for the contraction. Myosin regulatory light chain (MRLC) in the actin cup was shown to be phosphorylated at the activation sites Ser-19 and Thr-18, by immunoblotting with anti-phosphoepitope antibodies. The phosphorylation of MRLC was also confirmed by a (32)P in vivo labeling experiment. The CL-A-induced cortical contraction may be a good model system for studying the mechanism of cytokinesis.

Actins↗
PubMed2001

Power Doppler sonography of the kidney: effect of Valsalva's maneuver.

PURPOSE: It has been reported that an intra-abdominal pressure (IAP) above 15 mm Hg may cause oliguria and that an IAP above 25 mm Hg may cause anuria. Because Valsalva's maneuver yields an IAP exceeding 180 mm Hg, it is presumed to affect renal perfusion. We evaluated the ability of power Doppler sonography to depict the changes in renal blood flow during Valsalva's maneuver. METHODS: Seven healthy men aged 21-24 years and 1 50-year-old man with massive ascites participated in the study. With each healthy subject lying in a supine position, longitudinal power Doppler sonograms of the kidney were obtained and analyzed semiquantitatively during Valsalva's maneuver. Also, in the patient with massive ascites, power Doppler sonography was performed before and after paracentesis. RESULTS: Along with an increase in IAP, monitored as expiratory pressure during Valsalva's maneuver, power Doppler signals decreased as indicated by both visual impression and computer scores. In the patient with massive ascites, signal intensity increased after paracentesis. CONCLUSIONS: Our results demonstrated that an increase in IAP within the physiologic range affects renal perfusion and that power Doppler sonography depicts semiquantitatively the change in renal blood flow.

Adult↗
PubMed2001

Immunization of the elderly to boost immunity against varicella-zoster virus (VZV) as assessed by VZV skin test reaction.

The utility of the VZV skin test in detecting individual susceptibility to varicella and zoster was determined. Its specificity particularly with regard to herpes simplex was also established. The VZV skin test was negative or weakly positive during the early stage of herpes zoster, and strongly positive during recovery from that disease. A small-scale clinical trial to immunize elderly individuals has been performed for the purpose of preventing herpes zoster, and, perhaps, severe post-herpetic neuralgia as well. Sixty individuals > or = 50 years old were screened for VZV antibodies by IAHA test and were given a VZV skin test for cell-mediated immunity. All were seropositive, but eight were skin-test negative. Thirty-seven individuals including the eight with negative skin tests were immunized with one dose of varicella vaccine (3.0 x 10(4) PFU/dose). After 5-7 weeks, the skin test reaction showed increased positivity, with a change in score from (-) to (+, ++) in 7/8 subjects, from (+) to (++, +++) in 3/5 subjects, and from (++) to (+++) in 6/10 subjects. Enhancement of the VZV antibody titer (defined as twofold or greater) was observed in all 15 vaccine recipients with a prevaccination titer of < or = 1:16, and in 19 of 24 subjects with a prevaccination titer of > or = 1:32. These results indicate that giving live varicella vaccine with a high viral titer can induce a good boost immunity particularly cell-mediated immunity to VZV in the elderly.

Aged↗
PubMed2001

Transient seizure activity demonstrated by Tc-99m HMPAO SPECT and diffusion-weighted MR imaging.

Cerebral perfusion single photon emission computed tomography (SPECT) has been used to confirm the localization of the epileptic focus and the evaluation of seizure. Recently, diffusion-weighted MR imaging (DWI) has been recognized for evaluation of seizure activity. We describe a case of transient seizure activity demonstrated by Tc-99m HMPAO SPECT and DWI. This patient was a 61-year-old woman with a 10-month history of right middle cerebral artery (MCA) infarction who had a generalized seizure during MRI. DWI immediately after seizure showed transient hyperintensity in the right frontal gray matter and the white matter, and these apparent diffusion coefficients (ADC) were transiently decreased. This transient hyperintensity on DWI corresponded to transient hyperperfusion identifying the epileptic focus on interictal Tc-99m HMPAO SPECT. Transient sustained seizure activity might cause these changes on DWI and SPECT. It was considered that interictal Tc-99m HMPAO SPECT showed the delayed hyperperfusion caused by excitatory neuronal overaction and DWI showed cytotoxic edema seizure-induced by energy failure of the membrane-bound Na/K-ATPase pump.

Cerebral Infarction↗