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Y Kubota

Publications and source records attributed to Y Kubota.

At least 37 records · Page 2Linked to original sources
PubMed2005

Observation of thirteen new exclusive multibody hadronic decays of the psi(2S).

Using data accumulated with the CLEO detector corresponding to an integrated luminosity of [symbol: see text] = 5.63 pb(-1) on the peak of the psi(2S) [3.08 x 10(6) psi(2S) decays] and 20.70 pb(-1) at square root of[s] = 3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the psi(2S): eta3pi, &eta'3pi, rhoK+K-, K+K-pi+pi-pi0, 2(K+K-), 2(K+K-)pi0, rhopp, pppi+pi-pi0, etapp, ppK+K-, lambdalambdapi+pi-, lambdapK+, and lambdapK+pi+pi-, and more precise measurements of 8 previously measured modes: 2(pi+pi-), rhopi+pi-, 2(pi+pi-)pi0, omegapi+pi-, K+K-pi+pi-, omegaK+K-, phiK+K-, and pppi+pi-. We also report new branching fraction measurements of phipi+pi- and omegapp and upper limits for etapi+pi-, etaK+K-, and phivpp. Results are compared, where possible, with the corresponding J/psi branching ratios to provide new tests of the 12% rule.

Journal Article↗
PubMed2005

Branching fractions for psi(2S)-to-J/psi transitions.

We describe new measurements of the inclusive and exclusive branching fractions for psi(2S) transitions to J/psi using e(+)e(-) collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(chi(cJ) --> gamma(J/psi)) and B[psi(2S) --> light hadrons].

Journal Article↗
PubMed2005

Photon transitions in Upsilon(2S) and Upsilon(3S) decays.

We have studied the inclusive photon spectra in Upsilon(2S) and Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S) --> gammachi(bJ)(1P) and Upsilon(3S) --> gammachi(bJ)(2P) (J = 0, 1, 2). We measure the rate for a rare E1 transition Upsilon(3S) --> gammachi(b0)(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the eta(b)(1S) and eta(b)(2S) states.

Journal Article↗
PubMed2005

Observation of 1(-)0(-) final states from psi(2S) decays and e(+)e(-) annihilation.

Using CLEO data collected from CESR e(+)e(-) collisions at the psi(2S) resonance and nearby continuum at sqrt[s]=3.67 GeV, we report the first significantly nonzero measurements of light vector-pseudoscalar hadron pair production (including rhopi, omegapi, rhoeta, and K(*0)K0 ) and the pi(+)pi(-)pi(0) final state, both from psi(2S) decays and direct e(+)e(-) annihilation.

Journal Article↗
PubMed2005

Expression of thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, and orotate phosphoribosyl transferase in prostate cancer.

The enzymes thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyl transferase (OPRT) are involved in the metabolism of the anticancer drug 5-fluorouracil. No reports have examined the expression of these enzymes in prostate cancer (CaP). A total of 25 previously untreated, hormone-sensitive CaP tissue samples and 11 benign prostatic hyperplasia (BPH) specimens were examined. Tissue of CaP and BPH tissue samples were obtained from formalin-fixed, paraffin-embedded sections by laser-captured microdissection, and then RNA was extracted. mRNA expression of TS, DPD, TP, and OPRT was analyzed by quantitative reverse transcriptase-polymerase chain reaction. TS and OPRT expression levels were significantly higher in CaP samples than in BPH. DPD expression level in poorly differentiated CaP was significantly lower than that in CaP with more favorable--well or moderately differentiated--histopathology.

Cell Differentiation↗
PubMed2005

Radiation-induced apoptosis in peritoneal resident macrophages of C3H mice: selective involvement of superoxide anion, but not other reactive oxygen species.

Remarkably, apoptosis was induced by gamma-ray-irradiation in peritoneal resident macrophages (PRM) of C3H mice, but not other strains of mice. The mechanism of this strain-specific apoptosis induction was studied. Apoptosis in PRM was detected microscopically. Various radical scavengers were examined to identify the critical radicals involved in apoptosis induction. Intracellular peroxide levels were measured with a redox-sensitive dye, 2',7'-dichlorofluorescin diacetate (DCFH). Superoxide dismutase or catalase was introduced into the cells using commercially available Hemagglutinating Virus of Japan (HVJ) envelope vector kit. The enzyme activity of superoxide dismutase was also measured. Radiation-induced apoptosis in C3H mouse PRM was significantly suppressed by treatment with a pharmacological scavenger of superoxide anion, Tiron, but not with other radical scavengers. Intracellular peroxide levels were not elevated by irradiation at doses high enough to induce apoptosis maximally. Radiation-induced apoptosis in C3H mouse PRM was markedly suppressed by superoxide dismutase introduced into the cells using the HVJ envelope vector, but not catalase. The enzyme activity of superoxide dismutase in C3H mouse PRM was comparable with that in B6 mouse PRM. It was concluded that superoxide played the major role in radiation-induced apoptosis in the C3H mouse PRM and that cellular responses downstream or unrelated to superoxide might be responsible for the strain difference in radiation-induced apoptosis of mouse PRM.

Animals↗
PubMed2005

Effects of positive pressure in odontogenic keratocysts.

Intracystic fluid pressure is thought to be involved in odontogenic cyst growth. In this study, we investigated the effects of positive pressure on the expression of interleukin-1alpha (IL-1alpha), matrix metalloproteinases (MMPs), and prostaglandin E2 (PGE2) in odontogenic keratocysts to determine whether this pressure stimulates inflammatory cytokine production and signaling of osteoclastogenic events. Positive pressure enhanced the expression of IL-1alpha mRNA and protein in odontogenic keratocyst epithelial cells, and increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and the epithelial cells. The pressure-induced secretions were inhibited by an interleukin-1 receptor antagonist. Recombinant human interleukin-1alpha (rhIL-1alpha) increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in the fibroblasts. Furthermore, in the fibroblasts, rhIL-1alpha enhanced the expression of macrophage colony-stimulating factor (M-CSF) mRNA, and rhIL-1alpha-induced PGE2 increased the expression of nuclear factor kappaB ligand (RANKL) mRNA. Thus, positive pressure may play a crucial role in odontogenic keratocyst growth via stimulating the expression of IL-1alpha in epithelial cells.

Carrier Proteins↗
PubMed2005

Evaluation of intrarenal hemodynamics by Doppler ultrasonography for renoprotective effect of angiotensin receptor blockade.

AIMS: It has been shown that both angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II type 1 receptor blockers (ARB) have renoprotective effects via mechanisms that are independent of blood pressure reduction. The aim of this study was to evaluate the intrarenal hemodynamic change with ARB by renal Doppler ultrasonography (RDU) and to assess the mechanism of ARB in patients with hypertension. METHODS: Thirty hypertensive patients with renal insufficiency caused by glomerular diseases, diabetes and hypertensive nephrosclerosis were included in this study. RDU was performed before and one week after taking ARB. Resistance index (RI) (peak systolic velocity - end diastolic velocity/peak systolic velocity) in the intrarenal segmental artery were calculated, and the amounts of urinary protein or albumin were determined. RESULTS: We defined patients whose microalbuminuria or proteinuria was reduced by greater than 30% by ARB as responders (n = 22) and defined other patients as non-responders (n = 8). There were no significant differences between the responder and non-responder groups in baseline characteristics. RI was significantly improved by ARB in the responder group, but not in the non-responder group. The reduction of RI after ARB treatment was most prominent in patients with hypertensive nephrosclerosis. CONCLUSIONS: Improvement in intrarenal hemodynamics might play an important role in the mechanisms of the renoprotective effect of ARB in patients with hypertension.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2004

Search for the lepton-flavor-violating leptonic B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+).

We have searched a sample of 9.6 x 10(6) BB events for the lepton-flavor-violating leptonic B decays, B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+). The tau lepton was detected through the decay modes tau-->lnunu(-) , where l=e, mu. There is no indication of a signal, and we obtain the 90% confidence level upper limits B(B(0)-->mu(+/-)tau(-/+))<3.8 x 10(-5) and B(B(0)-->e(+/-)tau(-/+))<1.3 x 10(-4).

Journal Article↗
PubMed2004

First observation and Dalitz analysis of the D0-->K(0)Setapi(0) decay.

Using 9.0 fb(-1) of integrated luminosity in e(+)e(-) collisions near the Upsilon(4S) mass collected with the CLEO II.V detector we report the first observation of the decay D0-->K(0)(S)etapi(0). We measure the ratio of branching fractions, BR(D0-->K(0)(S)etapi(0))BR / (D0-->K(0)(S)pi(0))=0.46+/-0.07+/-0.06. We perform a Dalitz analysis of 155 selected D0-->K(0)(S)etapi(0) candidates and find leading contributions from a(0)(980)K(0)(S) and K(*)(892)eta intermediate states.

Journal Article↗
PubMed2004

Wess-Zumino current and the structure of the decay tau- -->K- pi- K+ nu tau.

We present the first study of the vector (Wess-Zumino) current in tau(-)-->K-pi-K+nu(tau) decay using data collected with the CLEO III detector at the Cornell Electron Storage Ring. We determine the quantitative contributions to the decay width from the vector and axial vector currents. Within the framework of a model by Kühn and Mirkes, we identify the quantitative contributions to the total decay rate from the intermediate states omegapi, rho(')pi, and K*K.

Journal Article↗
PubMed2004

Observation of the Hadronic transitions chi(b1,2)(2P)-->omegaUpsilon(1S).

The CLEO Collaboration has made the first observations of hadronic transitions among bottomonium (bbmacr;) states other than the dipion transitions among Upsilon(nS) states. In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S)-->gammaomegaUpsilon(1S) that is consistent with radiative decays Upsilon(3S)-->gammachi(b1,2)(2P), followed by chi(b1,2)(2P)-->omegaUpsilon(1S). The branching ratios we obtain are B[chi(b1)(2P)-->omegaUpsilon(1S)]=(1.63(+0.35+0.16)(-0.31-0.15))% and B[chi(b2)(2P)-->omegaUpsilon(1S)]=(1.10(+0.32+0.11)(-0.28-0.10))%, in which the first error is statistical and the second is systematic.

Journal Article↗
PubMed2004

Relation between size of odontogenic jaw cysts and the pressure of fluid within.

Intracystic fluid pressure may have a crucial role in the growth of odontogenic jaw cysts. In this study, we investigated the relation between the size of the cyst and the pressure of the fluid within odontogenic keratocysts, dentigerous cysts, and radicular cysts. The radiolucent area of the cyst on a panoramic radiograph was linearly related to the volume in the cavity, and the correlation coefficient (gamma) was 0.70 (n = 25, P < 0.001). Intracystic fluid pressure correlated negatively with the radiolucent area in odontogenic keratocysts (gamma = -0.76, n = 9, P = 0.02), dentigerous cysts (gamma = -0.54, n = 16, P = 0.03), and radicular cysts (gamma = -0.69, n = 10, P = 0.03). The values of [(intracystic fluid pressure (mmHg)) x (radiolucent area (cm(2)))] did not differ significantly among the three types of cyst. Intracystic fluid pressure may therefore be negatively related to the size of all three types of cyst.

Adolescent↗
PubMed2004

Constitutively activated phosphatidylinositol 3-kinase primes platelets from patients with chronic myelogenous leukemia for thrombopoietin-induced aggregation.

In this study, we examined the effect of thrombopoietin (TPO) on the aggregation of platelets from 40 patients with myeloproliferative disorders (MPDs), including 17 patients with chronic myelogenous leukemia in the chronic phase (CML-CP), 10 with polycythemia vera, 10 with essential thrombocythemia, and three with myelofibrosis. TPO by itself dose-dependently induced the aggregation of platelets from patients with CML-CP but not from those with other MPDs or with CML-CP in cytogenetical complete remission. The expression of CD63 in CML-CP platelets was induced by TPO treatment. Phosphatidylinositol 3-kinase (PI3-kinase) was constitutively activated in CML-CP platelets. Pretreatment with PI3-kinase inhibitors (wortmannin and LY294002) dose-dependently inhibited TPO-induced aggregation of CML-CP platelets. The Abl kinase inhibitor imatinib mesylate and the Jak inhibitor AG490 suppressed TPO-induced aggregation of CML-CP platelets. Pretreatment with imatinib mesylate, but not with AG490, inhibited the activity of PI3-kinase in CML-CP platelets. In addition, tyrosine phosphorylation of Jak2 was undetected in CML-CP platelets before TPO treatment. These findings indicate that the constitutive activation of PI3-kinase primes CML-CP platelets for the aggregation induced by TPO, and that Bcr-Abl, but not Jak family protein tyrosine kinases, are involved in the constitutive activation of PI3-kinase in CML-CP platelets.

Androstadienes↗
PubMed2004

Inhibition of nuclear factor kappa B activation and inducible nitric oxide synthase transcription by prolonged exposure to high glucose in the human keratinocyte cell line HaCaT.

BACKGROUND: In human skin, inducible nitric oxide synthase (iNOS) appears to be a key enzyme during wound healing and has roles in protection from infection. We speculated that diabetic skin complications such as delayed wound healing and skin infection were due to iNOS activity altered by high glucose in skin keratinocytes. OBJECTIVES: The purpose of this study was to see how high levels of glucose affect iNOS activity in the human keratinocyte cell line (HaCaT). METHODS: HaCaT cells were exposed to high glucose for 1 day or 10 days. We measured nitric oxide (NO) end product nitrite in the culture medium using the Griess reagent, and intracellular tetrahydrobiopterin (BH(4), a cofactor of NOS) content by using high-performance liquid chromatography, analysed the expression level of iNOS mRNA by the reverse transcriptase-polymerase chain reaction method and evaluated the DNA binding activity of nuclear factor kappa B (NF-kappaB) by enzyme-immunoassay. RESULTS: Short-term exposure (1 day) to a high level of glucose increased BH(4) and iNOS activity at the post-translational level. However, long-term exposure (10 days) to high glucose downregulates NF-kappaB binding activity and inhibits iNOS transcription and its activity. CONCLUSIONS: Pretreatment with high glucose for 10 days down-regulated NF-kappaB activity and inhibited iNOS transcription and NO production, implying the involvement of a deficiency in NO synthesis in both skin infection and impaired wound healing in diabetic patients.

Antioxidants↗
PubMed2003

Gradient liquid chromatography of leucine-enkephalin peptide and its metabolites with electrochemical detection using highly boron-doped diamond electrode.

Boron-doped diamond thin film (BDD) electrodes have been used to study the oxidation reactions and to detect leucine-enkephalinamide (LEA) and its metabolites, tyrosine (T), tyrosyl-alanine (TA), tyrosyl-alanine-glycine (TAG) and leucine-enkephalin (LE) using cyclic voltammetry (CV), flow-injection analysis (FIA), and gradient liquid chromatography (LC) with amperometric detection. At diamond electrodes, well-defined and highly reproducible cyclic voltammograms were obtained with signal-to-background (S/B) ratios 5-10 times higher than those observed for glassy carbon (GC) electrodes. The analytical peaks of LC for LEA and its metabolites were well resolved. No deactivation of BDD electrodes was found after several experiments with standard as well as plasma samples, indicating high stability of the electrode. Calibration curves were linear over a wide range from 0.06 to 30 microM with regression coefficients of 0.999 for all compounds. The limits of detection obtained based on a signal-to-noise ratio of 3:1 were 3, 2.2, 2.7, 20 and 11 nM for T, TA, TAG, LE and LEA, respectively. These values were at least one order lower than those obtained at GC electrodes, which has given limits of detection of 22.88, 20.64, 89.57, 116.04 and 75.67 for T, TA, TAG, LE and LEA, respectively. Application of this method to real samples was demonstrated and validated using rabbit serum samples. This work shows the promising use of conducting diamond as an amperometric detector in gradient LC, especially for the analysis of enkephalinamide and its metabolites.

Boron↗