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Biomedical subjects

H Miyake

Publications and source records attributed to H Miyake.

At least 55 records · Page 3Linked to original sources
PubMed2003

Observation of B-->K*l+l-.

We report the observation of the flavor-changing neutral current decay B-->K(*)l(+)l(-) and an im-proved measurement of the decay B-->Kl(+)l(-), where l represents an electron or a muon, with a data sample of 140 fb(-1) accumulated at the Upsilon(4S) resonance with the Belle detector at KEKB. The results for the branching fractions are B(B-->K(*)l(+)l(-))=(11.5(+2.6)(-2.4)+/-0.8+/-0.2)x10(-7) and B(B-->Kl(+)l(-))=(4.8(+1.0)(-0.9)+/-0.3+/-0.1)x10(-7), where the first error is statistical, the second is systematic and the third is from model dependence.

Journal Article↗
PubMed2003

Observation of a narrow charmoniumlike state in exclusive B+/--->K+/-pi+pi-J/psi decays.

We report the observation of a narrow charmoniumlike state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has a mass of 3872.0+/-0.6(stat)+/-0.5(syst) MeV, a value that is very near the M(D0)+M(D(*0)) mass threshold. The results are based on an analysis of 152M B-Bmacr; events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The signal has a statistical significance that is in excess of 10sigma.

Journal Article↗
PubMed2003

Measurement of branching fractions and polarization in B-->phiK(*) decays.

We present the first measurement of decay amplitudes in B-->phiK* and measurements of branching fractions in B-->phiK(*) decays based on 78.1 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e+e- storage ring. The decay amplitudes for the different phiK*0 helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitudes are |A0|2=0.43+/-0.09+/-0.04, |A(perpendicular)|2=0.41+/-0.10+/-0.04, arg((A(parallel))=-2.57+/-0.39+/-0.09, and arg((A(perpendicular))=0.48+/-0.32+/-0.06. The direct CP-violating asymmetries are found to be consistent with zero.

Journal Article↗
PubMed2003

Observation of B0 -->D0K0 and B0 -->D0K*0 decays.

We report on a search for B(0)-->D(*0)K(*0) decays based on 85 x 10(6) BB events collected with the Belle detector at KEKB. The B(0)-->D0K(0) and B(0)-->D0K(*0) decays have been observed for the first time with the branching fractions B(B(0)-->D0K(0))=(5.0(+1.3)(-1.2)+/-0.6)x10(-5) and B(B(0)-->D0K(*0))=(4.8(+1.1)(-1.0)+/-0.5)x10(-5). No significant signal has been found for the B(0)-->D(*0)K*0) and B(0)-->D(*0)K(*0) decay modes, and upper limits at 90% C.L. are presented.

Journal Article↗
PubMed2003

Measurement of branching fractions for B-->eta(c)K(*) decays.

We report measurements of branching fractions for charged and neutral B-->eta(c)K decays where the eta(c) meson is reconstructed in the K(0)(S)K+/-pi(-/+), K+K-pi(0), K(*0)K-pi(+), and pp; decay channels. The neutral B0 channel is a CP eigenstate and can be used to measure the CP violation parameter sin(2phi(1). We also report the first observation of the B0-->eta(c)K(*0) mode. The results are based on an analysis of 29.1 fb(-1) of data collected by the Belle detector at KEKB.

Journal Article↗
PubMed2003

Pancreaticobiliary maljunction: retrospective and nationwide survey in Japan.

Pancreaticobiliary maljunction (PBM) is a congenital anomaly defined as a union of the pancreatic and biliary duct that is located outside the duodenal wall. The Japanese Study Group on Pancreaticobiliary Maljunction and the Committee for Registration enrolled and analyzed 1627 patients with PBM who had been diagnosed and treated from January 1, 1990 to December 31, 1999 at 141 hospitals throughout the country. There were 1239 patients with dilatation of the bile duct (group A) and 388 patients without dilatation (group B). The average age was 24 years in group A and 47 years in group B; the age was significantly higher in group B. The type of confluence between the terminal choledochus and the pancreatic duct has been classified into three types (type a, right-angle type; type b, acute-angle type; and type c, complex type). In group A, type a accounted for 57.9% and was significantly more frequent compared with the other types (type b, 32.4%; type c, 5.6%). In group B, type b accounted for 60.8%, being significantly more frequent compared with the other types (type a, 29.4%; type c, 7.2%). Subjective symptoms, preoperative complications (e.g., liver dysfunction and acute pancreatitis), pancreatic stone, and pancreatic duct morphological abnormality were significantly more frequent in group A. However, the amylase levels in the bile and gallbladder were significantly higher in group B, and the presence of gallstone and morphological abnormality of the gallbladder was significantly more frequent in group B. The occurrence rate of cancer in the biliary tract was 10.6% in group A and 37.9% in group B, being significantly higher in group B. In group A, cancer of the extrahepatic bile duct was seen in 33.6% and cancer of the gallbladder was seen in 64.9%, but gallbladder cancer was present significantly more frequently in the patients with diffuse or cylindrical dilatation, and bile duct cancer was present significantly more frequently in the patients with cystic dilatation. In group B, 93.2% of the patients had gallbladder cancer, and bile duct cancer was found in as few as 6.8%. Against this background Japanese surgeons regard cholecystectomy, resection of the extrahepatic bile duct, and hepaticojejunostomy as standard operations for PBM with dilatation of the bile duct. However, opinion on whether or not the bile duct should be removed in the treatment of PBM without dilatation of the bile duct has been divided among Japanese surgeons. A randomized controlled trial is necessary.

Adolescent↗
PubMed2003

Increased urinary 8-hydroxy-2'-deoxyguanosine excretion after ileal neobladder replacement.

OBJECTIVES: To examine whether orthotopic neobladder replacement using either ileum or colon segments results in increased oxidative stress, by measuring urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), one of the most commonly used markers for evaluating oxidative DNA damage. PATIENTS, SUBJECTS AND METHODS: Urinary levels of 8-OHdG and creatinine, urine analysis, nutritional status, and acid-base and electrolyte balances, were assessed in 22 patients with an ileal neobladder, 28 with a colon neobladder, 37 with an ileal conduit and 22 healthy volunteers. The results from both types of orthotopic neobladder, the ileal conduit and in the healthy controls were compared. RESULTS: The mean (sd) ratios of urinary 8-OHdG to urinary creatinine in patients with an ileal neobladder, colon neobladder, ileal conduit and in controls were 20.4 (7.8), 15.2 (4.3), 15.9 (5.1) and 15.2 (5.4) ng/mg, respectively. The urinary 8-OHdG ratio in the first group was significantly higher than in the other three groups. Among patients with a neobladder, the urinary 8-OHdG ratio was closely associated with the degree of pyuria, but not age, gender, the interval from surgery, body weight, height, serum creatinine or the degree of metabolic acidosis. CONCLUSIONS: These findings suggest that creating an ileal neobladder caused significantly greater oxidative stress than a colon neobladder, ileal conduit, or that in healthy controls. Therefore, it is recommended to conduct a careful long-term follow-up considering the possible development of malignant disease after urinary diversion, especially by an ileal neobladder.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2003

Overexpression of the cytoprotective protein clusterin decreases radiosensitivity in the human LNCaP prostate tumour model.

OBJECTIVE: To evaluate the effect of clusterin overexpression on radiation-induced tumour growth rates and apoptosis in human prostate LNCaP cells, as prostate cancer cells are relatively resistant to radiation-induced apoptosis and local recurrences are common, but overexpression of the anti-apoptotic protein clusterin can accelerate progression to androgen-independence and to confer a chemoresistant phenotype in various prostate cancer models. MATERIALS AND METHODS: Western blot analysis and immunohistochemistry were used to compare clusterin expression levels in parental (P) and clusterin-transfected (T) LNCaP cells in vitro and in vivo. The effects of radiation on clusterin-expression in both parental LNCaP/P and clusterin-transfected LNCaP/T tumours were analysed by Northern blot analysis. The cellular response to radiation was determined up to 3 weeks after irradiation using tetrazolium and re-growth assays, and cell-cycle analysis by flow cytometry. RESULTS: Clusterin mRNA expression increased from undetectable to low levels in LNCaP/P tumours after radiation and more than three-fold in LNCaP/T tumours. Clusterin overexpression decreased the radiosensitivity in a time-dependent manner, reducing the extent of growth arrest and apoptosis by up to 54%. Re-growth assays showed that the improved survival rates of LNCaP/T cells after radiation did not change after 3 days, remaining constant over 3 weeks. CONCLUSIONS: These results identify clusterin as a promoter of cell survival that may help mediate resistance to radiation-induced apoptosis. Furthermore, clusterin overexpression seems to provide an extended protection against radiation-induced cell cycle arrest and apoptosis.

Apoptosis↗
PubMed2002

Radiative B meson decays into kpigamma and kpipigamma final states.

We report observations of radiative B meson decays into the K+pi(-)gamma and K+pi(-)pi(+)gamma final states. In the B0-->K+pi(-)gamma channel, we present evidence for decays via an intermediate tensor meson state with a branching fraction of B(B0-->K(*)(2)(1430)(0)gamma)=[1.3+/-0.5(stat)+/-0.1(syst)]x10(-5). We measure the branching fraction B(B+-->K+pi(-)pi(+)gamma)=[2.4+/-0.5(stat) +0.4-0.2(syst)]x10(-5), in which the B+-->K(*0)pi(+)gamma and B+-->K+rho(0)gamma channels dominate. The analysis is based on a data set of 29.4 fb(-1) recorded by the Belle experiment at the KEKB collider.

Journal Article↗
PubMed2002

Observation of B+/- -->omegaK+/- decay.

We report the first observation of the charmless two-body mode B+/--->omegaK+/- decay, and a new measurement of the branching fraction for the B+/--->omegapi(+/-) decay. The measured branching fractions are B(B+/--->omegaK+/-)=(9.2(+2.6)(-2.3)+/-1.0)x10(-6) and B(B+/--->omegapi(+/-))=(4.2(+2.0)(-1.8)+/-0.5)x10(-6). We also measure the partial rate asymmetry of B+/--->omegaK+/- decays and obtain A(CP)=-0.21+/-0.28+/-0.03. The results are based on a data sample of 29.4 fb(-1) collected on the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗
PubMed2002

Observation of the decay B(0)-->D(+/-)D(*-/+).

We report the first observation of the decay B(0)-->D(+/-)D(*-/+) with the Belle detector at the KEKB e(+)e(-) Collider operated at the Upsilon(4S) resonance. The sum of branching fractions B(B(0)-->D(+)D(*-))+B(B(0)-->D(-)D(*+)) is measured to be (1.17+/-0.26(+0.22)(-0.25))x10(-3) using the full reconstruction method where both charmed mesons from B0 decays are reconstructed. A consistent value [(1.48+/-0.38(+0.28)(-0.31))x10(-3)] is obtained using a partial reconstruction technique that uses only the slow pion from the D(*-)-->D(-0)pi(-) decay and a fully reconstructed D(+) to reconstruct the B(0).

Journal Article↗
PubMed2002

Production of prompt charmonia in e(+)e(-) annihilation at square root of s approximately equals 0.6 GeV.

The production of prompt J/psi, psi(2S), chi(c1), and chi(c2) is studied using a 32.4 fb(-1) data sample collected with the Belle detector at Upsilon(4S) and at 60 MeV below the resonance. The yield of prompt J/psi mesons in the Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Upsilon(4S)-->J/psiX) < 1.9 x 10(-4) at the 95% confidence level, and find sigma(e(+)e(-)-->J/psiX) = 1.47 plus/minus 0.10 plus/minus 0.13 pb. The cross sections for prompt psi(2S) and direct J/psi are measured. The J/psi momentum spectrum, production angle distribution, and polarization are studied.

Journal Article↗
PubMed2002

Health-related quality of life after radical cystectomy for bladder cancer: a comparison of ileal conduit and orthotopic bladder replacement.

OBJECTIVE: To compare the health-related quality of life (HRQoL) after radical cystectomy in patients with an ileal conduit or an orthotopic neobladder. PATIENTS AND METHODS: The study included 85 men who underwent radical cystectomy for bladder cancer, comprising 48 with an orthotopic neobladder (26 with an ileal and 22 with a colon neobladder) and 37 with an ileal conduit. HRQoL was evaluated using the Short Form-36 survey containing 36 questions assessing eight aspects, including physical functioning, role-physical functioning, bodily pain, general health, vitality, social functioning, role-emotional functioning and mental health. RESULTS: The mean follow-up periods for patients with a neobladder (ileal and sigmoid) and with an ileal conduit was 45.9 (38.2 and 53.1, respectively) and 130.9 months, respectively. Scale scores were not affected by the duration of follow-up in either group. There was no significant difference in any scale scores between the neobladder and ileal conduit groups. However, general health and social functioning in both the neobladder and ileal conduit groups appeared to be significantly lower than those in the general population in the USA. Furthermore, patients with a colon neobladder had a significantly higher score for role-emotional functioning than those with an ileal neobladder, while there was no significant difference in the remaining seven scores between patients with ileal and colon neobladders. CONCLUSIONS: Six of the eight scales of HRQoL were favourable in both patients with a neobladder or an ileal conduit, and there was no significant difference between these groups. In addition, the HRQoL of patients with an orthotopic neobladder (except for role-emotional functioning) was unaffected by the segment of the intestine used for neobladder construction. Therefore, patients with both types of urinary diversion were generally satisfied with their overall health and quality of life.

Colon↗
PubMed2002

Reproducibility of pulsed Doppler measurements of the maternal renal circulation in normal pregnancies and those with pregnancy-induced hypertension.

OBJECTIVE: To assess the inter- and intraobserver reproducibilities of pulsed Doppler measurements of the maternal renal circulation in normal pregnancies and those affected by pregnancy-induced hypertension. MATERIALS AND METHODS: Color and pulsed Doppler ultrasound was used to measure acceleration time and resistance index in the renal segmental and interlobar arteries. For the investigation of interobserver reproducibility, two sonographers performed measurements blindly in six normal pregnant women and 14 women with pregnancy-induced hypertension between 28 and 36 weeks' gestation. A second group of 10 patients between 30 and 35 weeks' gestation were examined by one sonographer to assess the level of intraobserver reproducibility of measurements. For each patient in this group, the flow waveform was measured three times in succession. Calculations of the intraclass correlation coefficient Ri were used to determine the level of reproducibility. RESULTS: The interobserver Ri and intraobserver Ri for acceleration time in the segmental artery were 0.95 and 0.96 and for the interlobar artery they were 0.97 and 0.98, respectively. For the resistance index, these values were 0.01 and 0.01 in the segmental artery and 0.52 and 0.29 in the interlobar artery. CONCLUSION: Both the inter- and intraobserver reproducibility of acceleration time measurements in the renal segmental and interlobar arteries were clinically acceptable but the equivalent reproducibilities of resistance index measurements were poor.

Adult↗
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

"Intermolecular" trapping of a nonheme Fe(IV)=O intermediate.

The reactions of Fe(III)(TPA) (TPA = tris(2-pyridylmethyl)amine) complexes with 2-methyl-1-phenyl-2-propyl-hydroperoxide (MPPH) delivered by syringe pump under anaerobic conditions afford nearly quantitative conversion of MPPH to products derived from the benzyl radical. These results unequivocally show that MPPH breaks down by O-O bond homolysis, leading to the formation of the benzyl radical and a high valent Fe(IV)=O species. Without added substrates, the benzyl radical reacts with the high valent species to form benzyl alcohol or benzyl halides. The Fe(IV)=O species can also effect the two-electron oxidation of added substrates such as thioanisole, cyclohexanol, and cyclooctene under appropriate conditions. The oxidation of thioanisole and cyclohexanol is likely facilitated by pre-equilibrium binding of the substrate to the metal center, allowing these substrates to intercept the high valent iron-oxo species as it forms. These results suggest the importance of close proximity to direct the high valent metal center down a desired pathway.

Chemical Phenomena↗