Biomedical subjects

S Nishida

Publications and source records attributed to S Nishida.

At least 19 recordsLinked to original sources

PubMed2007

Ten-year experience in porto-caval hemitransposition for liver transplantation in the presence of portal vein thrombosis.

Porto-caval hemitransposition (PCH) in liver transplantation allows revascularization of the liver when the porto-mesenteric axis is thrombosed. We, here, review our experience over an 11-year period. A total of 23 patients underwent liver transplantation using PCH. Immunosuppression was based on tacrolimus, with sirolimus used in case of renal insufficiency. Most common diagnoses were hepatitis C, Laennec's, Budd-Chiari and cryptogenic cirrhosis. Six patients needed splenectomy prior to transplant, 5 during transplant, 1 post-transplant, 11 had no splenectomy. Overall survival was 60% at 1 year and 38% at 3 years, with 10 of 23 patients currently alive and the longest survivor at 9.3 years. Most common cause of death was sepsis/multisystem organ failure, followed by pulmonary embolism. A total of 7/23 patients experienced post-operative gastrointestinal bleeding episodes, 6/23 patients developed thrombosis of the vena cava (median 162 days post-op). Post-operative ascites was noted in almost all patients. Renal dysfunction was commonly seen even after the first month post-transplant. PCH offers a feasible option for liver transplantation in those patients with complex thrombosis of the mesenteric and portal circulation.

Adult↗

PubMed2006

Observation of B+ --> Lambda c+ Lambda c- K+ and B0 --> Lambda c+ Lambda c- K0 decays.

We report the first measurements of the doubly charmed baryonic B decays B --> Lambda c+ Lambda c- K. The B+ --> Lambda c+ Lambda c- K+ decay is observed with a branching fraction of (6.5(-0.9)(+1.0)+/-1.1+/-3.4)x10(-4) and a statistical significance of 15.4sigma. The B0 --> Lambda c+ Lambda c- K0 decay is observed with a branching fraction of (7.9(-2.3)(+2.9)+/-1.2+/-4.1)x10(-4) and a statistical significance of 6.6sigma. The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of the Lambda c+ --> pK- pi+ decay branching fraction. The analysis is based on 357 fb(-1) of data accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider.

Journal Article↗

PubMed2006

Study of J/psi-->pp[over],LambdaLambda[over] and observation of eta(c)-->LambdaLambda[over] at Belle.

We study the baryonic charmonium decays of B mesons B+-->etacK+ and B+-->J/psiK+, where the etac and J/psi subsequently decay into a pp[over] or LambdaLambda[over] pair. We measure the J/psi-->pp[over] and LambdaLambda[over] anisotropy parameters alphaB=-0.60+/-0.13+/-0.14 (pp[over]), -0.44+/-0.51+/-0.31 (LambdaLambda[over ]) and compare to results from e;{+}e;{-}-->J/psi formation experiments. We also report the first observation of etac-->LambdaLambda[over]. The measured branching fraction is B(etac-->LambdaLambda[over ])=(0.87(+0.24)/(-0.21)(stat)(+0.09/-0.14) (syst)+/-0.27(PDG))x10-3. This study is based on a 357 fb-1 data sample recorded on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider.

Journal Article↗

PubMed2006

Observation of a near-threshold D(0)D[over](0)pi(0) enhancement in B-->D(0)D[over](0)pi(0)Kappa decay.

We report the first observation of a near-threshold enhancement in the D(0)D[over](0)pi(0) system from B-->D(0)D[over](0)pi(0)Kappa decays using a 414 fb(-1) data sample collected at the Upsilon(4S) resonance. The enhancement peaks at a mass M=3875.2+/-0.7(+0.3)/(-1.6) +/-0.8 MeV/c2 and the branching fraction for events in the peak is B(B-->D(0)D[over](0)pi(0)Kappa)=(1.22+/-0.31(+0.23)/(-0.30))x10(-4). The data were collected with the Belle detector at the KEKB energy-asymmetric e+ e- collider.

Journal Article↗

PubMed2006

Measurement of the quark mixing parameter cos2phi1 using time-dependent Dalitz analysis of B0 -->D[KS(0)pi + pi-]h0.

We present a measurement of the angle phi1 of the Cabibbo-Kobayashi-Maskawa unitarity triangle using a time-dependent Dalitz analysis of D-->KS(0)pi + pi- decays produced in neutral B meson decay to a neutral D meson and a light meson (B0-->D*h0). The method allows a direct extraction of 2phi1 and, therefore, helps to resolve the ambiguity between 2phi1 and pi-2phi1 in the measurement of sin2phi1. We obtain sin2phi1= 0.78 +/- 0.44 +/- 0.22 and cos2varphi1 = 1.87(-0.53-0.32)(+0.40 + 0.22). The sign of cos2phi1 is determined to be positive at 98.3% C.L.

Journal Article↗

PubMed2006

Measurement of D0-->pilnu(Klnu) form factors and absolute branching fractions.

Using a 282 fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider, we study D0 decays to K-l+nu and pi-l+nu final states. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q2=(pl+pnu)2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be B(D0-->Klnu)=(3.45+/-0.07stat+/-0.20syst)% and B(D0-->pilnu)=(0.255+/-0.019stat+/-0.016syst)% and the semileptonic form factors (within the modified pole model) f+K(0)=0.695+/-0.007stat+/-0.022syst and f+pi(0)=0.624+/-0.020stat+/-0.030syst.

Journal Article↗

PubMed2006

Evidence for large direct CP violation in B+/- --> rho(770)0K+/- from analysis of three-body charmless B+/- --> K+/-pi+/-pi+/- decays.

We report results on a Dalitz analysis of three-body charmless B+/- --> K+/-pi+/-pi+/- decay including searches for direct CP violation. We report the first observation of the decay B+/- --> f2(1270)K+/- with a statistical significance above 6sigma. We also observe first evidence for large direct CP violation in the B+/- --> rho(770)0K+/- channel. The results are obtained with a data sample that contains 386 10(6) BB pairs collected at the Y(4s) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.

Journal Article↗

PubMed2006

Measurement of forward-backward asymmetry and Wilson coefficients in B --> K*l+l-.

We report the first measurement of the forward-backward asymmetry and the ratios of Wilson coefficients and in A9/A7 and A10/A7 in B --> K*l+l-, where l represents an electron or a muon. We find evidence for the forward-backward asymmetry with a significance of 3.4sigma. The results are obtained from a data sample containing 386 x 10(6) BB pairs that were collected on the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.

Journal Article↗

PubMed2006

Measurement of azimuthal asymmetries in inclusive production of hadron pairs in e(+)e(-) annihilation at Belle.

The Collins effect connects transverse quark spin with a measurable azimuthal dependence in the yield of hadronic fragments around the quark's momentum vector. Using two different reconstruction methods, we find evidence of statistically significant azimuthal asymmetries for charged pion pairs in e(+)e(-) annihilation at a center-of-mass energy of 10.52 GeV, which can be attributed to a transverse polarization of the primordial quarks. The measurement was performed using a sample of 79 x 10(6) hadronic events collected with the Belle detector.

Journal Article↗

PubMed2006

Observation of b-->dgamma and determination of /Vtd/Vts/.

We report the observation of the flavor-changing neutral current process b-->dgamma using a sample of 386 x 106 B meson pairs accumulated by the Belle detector at the KEKB e+e- collider. We measure branching fractions for the exclusive modes B--->rho-gamma, B0rho0gamma, and B0omegagamma. Assuming that these three modes are related by isospin, we find B(B-->(rho,gamma)gamma)=[Formula: See Text] with a significance of 5.1sigma. This result is used to determine the ratio of Cabibbo-Kobayashi-Maskawa matrix elements /Vtd/Vts/ to be [Formula: See Text].

Journal Article↗

PubMed2006

Zoom endoscopic monitoring of small bowel allograft rejection.

BACKGROUND: The small bowel has been successfully transplanted in patients with irreversible intestinal failure. This report aims to describe endoscopic monitoring of small bowel rejection. METHODS: A magnification endoscope (zoom endoscope) was used in this study. In the first part of the study (October 1998 to March 2000, 271 endoscopy sessions), the specific endoscopic findings that correlated with rejection were determined. An analysis then was performed on data from the second period (March 2001 to November 2002, 499 sessions) to evaluate the zoom endoscope's accuracy in monitoring rejection. RESULTS: Specific endoscopic findings of rejection found in the first period included background erythema, villous congestion, blunted villous tip, and shortened villous height. When the rejection was successfully treated, endoscopic appearance returned to normal. On the basis of these findings, five endoscopic criteria (villous shortening, villous blunting, background erythema, villous congestion, and mucosal friability) were used to score endoscopic sessions in the second period. Endoscopic diagnosis of rejection was compared with histology. Adult patients showed a sensitivity of 45%, a specificity of 98%, a positive predictive value of 82%, and a negative predictive value of 88%. In pediatric patients, these values were, respectively, 61%, 84%, 57%, and 86%. On 59 distinct occasions (30 in period 1 and 29 in period 2) in which the results were endoscopy negative yet biopsy positive (mild) for rejection, we elected not to treat these rejections on the basis of clinical evaluation, and 58 (98%) resolved without further therapy. CONCLUSIONS: With the use of magnification, endoscopy is a useful tool for monitoring acute rejection in the small bowel allograft.

Adolescent↗

PubMed2006

Antiapoptotic function of 17AA(+)WT1 (Wilms' tumor gene) isoforms on the intrinsic apoptosis pathway.

The WT1 gene is overexpressed in human primary leukemia and a wide variety of solid cancers. The WT1 gene is alternatively spliced at two sites, yielding four isoforms: 17AA(+)KTS(+), 17AA(+)KTS(-), 17AA(-)KTS(+), and 17AA(-)KTS(-). Here, we showed that 17AA(+)WT1-specific siRNA induced apoptosis in three WT1-expressing leukemia cell lines (K562, HL-60, and Kasumi-1), but not in WT1-non-expressing lymphoma cell line (Daudi). 17AA(+)WT1-specific siRNA activated caspase-3 and -9 in the intrinsic apoptosis pathway but not caspase-8 in the extrinsic one. On the other hand, 17AA(-)WT1-specific siRNA did not induce apoptosis in the three WT1-expressing cell lines. The apoptosis was associated with activation of proapoptotic Bax, which was activated upstream of the mitochondria. Constitutive expression of 17AA(+)WT1 isoforms inhibited apoptosis of K562 leukemia cells induced by apoptosis-inducing agents, etoposide and doxorubicin, through the protection of mitochondrial membrane damages, and DNA-binding zinc-finger region of 17AA(+)WT1 isoform was essential for the antiapoptotic functions. We further studied the gene(s) whose expression was altered by the expression of 17AA(+)WT1 isoforms and showed that the expression of proapoptotic Bak was decreased by the expression of 17AA(+)KTS(-)WT1 isoform. Taken together, these results indicated that 17AA(+)WT1 isoforms played antiapoptotic roles at some points upstream of the mitochondria in the intrinsic apoptosis pathway.

Apoptosis↗

PubMed2006

Observation of a chi(c2)' candidate in gamma gamma --> DD production at belle.

We report on a search for new resonant states in the process gamma gamma --> DD. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c2. The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(c2)', the 2(3)P2 charmonium state.

Journal Article↗

PubMed2006

Intestinal transplantation for short bowel syndrome secondary to gastroschisis.

BACKGROUND/PURPOSE: Gastroschisis is the most frequent cause of pediatric intestinal transplantation. This study reviews our experience of intestinal transplantation secondary to gastroschisis to elucidate those factors affecting the outcome of children with short bowel syndrome. METHODS: A retrospective review was performed for children who underwent intestinal transplantation for gastroschisis at the University of Miami between June 2003 and August 1994. RESULTS: Thirty-two transplants were performed in 28 children with gastroschisis during the study period. Associated intestinal anomalies were present in 22 infants (atresia [n = 14], volvulus [n = 3], and/or ischemia [n = 16]). Spontaneous prenatal closure of gastroschisis, a rare anomaly associated with bowel atresia and ischemia because of a very small abdominal defect, was seen in 9 patients. Most of the patients had a complicated course and required multiple abdominal surgeries before transplant. Fifteen (53.6%) patients are currently alive at a median follow-up of 23.5 months. Short-term survival rate has significantly improved in recent years. CONCLUSIONS: Patients with complex gastroschisis and intestinal anomalies have a significant risk for progression to short bowel syndrome. Intestinal transplantation can be a lifesaving option and provides a satisfactory outcome for children with short bowel syndrome secondary to gastroschisis.

Child↗

PubMed2006

Routine use of auxiliary partial orthotopic liver transplantation for children with fulminant hepatic failure: Preliminary report.

Auxiliary partial orthotopic liver transplantation (APOLT) has been performed for both metabolic disorders and fulminant liver failure (FHF). When the native liver regenerates, the patients with FHF who undergo APOLT have a chance to withdraw immunosuppression. It may be most beneficial for children. This preliminary report describes our start to routinely offer APOLT as an option to standard OLT for children with FHF in 2005. Six children (ages 8 months to 8 years) received APOLT: 1 in 1996 and the others in 2005 and 2006. The donor ages ranged from 4 to 40 years. We used either a left lateral segment or a left lobe graft. The recipient left lobe, which was removed, showed submassive to massive necrosis at the time of transplantation. All children are alive and well. The first patient who received APOLT in 1996 is currently off immunosuppression with a fully recovered native liver; the grafted liver underwent complete atrophy. The 5 remaining subjects are receiving reduced levels of immunosuppression with close monitoring. Their serial liver biopsy specimens show slight to significant recovery. One developed hepatic artery thrombosis, requiring retransplantation. The native liver was retained at the time of retransplantation (redo APOLT). Other postoperative complications included a bile leak (n = 1), invasive mucomycosis of the arm (preexisting condition; n = 1), biliary stricture (n = 1), and acute cellular rejection (n = 3). Posttransplantation length of stay was 6 to 60 days (median, 15 days). In conclusion, APOLT can be safely performed in children with FHF displaying short-term outcomes comparable to standard transplantations.

Adolescent↗

PubMed2006

Pediatric liver transplant with Campath 1H induction--Preliminary report.

UNLABELLED: Since Campath 1H (C1H) has been successfully used in adult liver transplant recipients since 2001 in our program, we started to use it in children. PATIENTS AND METHODS: C1H induction was employed in 10 children with autoimmune hepatitis (AIH) (n = 6), primary sclerosing cholangitis (PSC) (n = 1), biliary atresia (n = 1), glycogen storage disease (n = 1), and Wilson's disease. Eight were primary transplants, and two retransplants. Patients ages ranged from 5 to 17 years. C1H was administered at a dose of 0.3 mg/kg on days 0, 4, and 7. Tacrolimus level was maintained at 5 to 10 ng/mL. No patient received maintenance steroids posttransplantation except two who were on steroid therapy at the time transplant. They were prescribed small doses of maintenance steroids. Median follow-up of C1H recipients was 679 days (range 115-1143). RESULTS: Postoperative courses were mostly uneventful except for one retransplant recipient who required prolonged hospitalization (40 days) for rehabilitation. Median hospital stay was 12 days (range 7-40 days). All 10 patients in the C1H group are currently alive and well with stable graft function. No opportunistic infection was observed in these patients to date. We compared six patients with AIH who received C1H to the historic control of 10 recipients with AIH who received conventional immunosuppression (tacrolimus + steroid). The patients treated with C1H showed significantly prolonged rejection-free survival. CONCLUSION: In our preliminary experience, C1H induction was well tolerated in pediatric liver recipients. Rejections-free survival was prolonged among recipients with AIH despite a low level of maintenance immunosuppression.

Adolescent↗

PubMed2006

Modelling number of services per conception of Japanese Black cattle by random regression.

Repeated records of number of services per conception (NSC) were collected on 607 Japanese Black cows. Data were analysed by random regression (RRM) and multiple trait (MTM) models, considering NSC in each parity as a separate trait. The chosen RRM included additive genetic and permanent environmental effects fitted with a third-order Legendre polynomials of parity. Heritabilities (h2) estimated by RRM decreased along the NSC trajectory from 0.15 in the first parity to 0.04 in the sixth parity and then increased up to 0.22 in the 10th parity. The corresponding estimates obtained by MTM ranged between 0.04 in parity 9 and 0.13 in parity 1. Permanent environmental proportions (p2) of the total phenotypic variance estimated by RRM showed similar pattern and magnitude to those of h2 estimated by the same method. On the contrary, the p2 estimated by MTM ranged between 0.04 in the first parity and 0.11 in the 10th parity. Additive genetic (r(G)), permanent environmental (r(P)) and phenotypic (r(PH)) correlations were also estimated. The values estimated by RRM between adjacent parities were higher than those of parities far apart. The corresponding values estimated by MTM were lower than those estimated by RRM with no certain trend. The results indicated that NSC in heifers is more heritable than NSC in cows with different parities. Reproductive traits are economically important traits and hence, they should be considered in breeding goals.

Analysis of Variance↗

PubMed2006

Refractory ascites after liver transplantation: an analysis of 1058 liver transplant patients at a single center.

A retrospective study of 1058 liver transplant recipients was performed to determine: (i) the incidence, etiology, timing, clinical features and treatment of refractory ascites (RA), (ii) risk factors for RA development, (iii) predictors of RA disappearance, (iv) predictors of survival following RA and (v) the impact of RA on patient survival. Sixty-two patients (5.9%) developed RA and its disappearance occurred in 27/62 cases. Patients having hepatitis C virus (HCV) had a significantly higher hazard rate of developing RA (p < 0.00001). No other baseline characteristic was associated with RA. Cox stepwise regression analysis of the hazard rate of RA disappearance found two significant factors: HCV recurrence as the reason for developing RA implied a poorer outcome (p = 0.006), whereas an unknown reason implied a favorable outcome (p = 0.02). In addition, survival following RA was significantly poorer among patients having bacterial peritonitis or HCV recurrence. Finally, the mortality rate was significantly (nearly 8.6 times) higher in patients following RA development while it was ongoing (p < 0.00001); however, if the RA disappeared, then the additional risk of death also disappeared. This study illustrates the importance of developing an optimal treatment strategy to (i) effectively treat RA if it develops and (ii) prevent hepatitis C recurrence.

Adolescent↗