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Biomedical subjects

Y Kishi

Publications and source records attributed to Y Kishi.

At least 37 records · Page 2Linked to original sources
PubMed2004

Prediction of hepatic artery thrombosis by protocol Doppler ultrasonography in pediatric living donor liver transplantation.

Hepatic arterial thrombosis (HAT) after liver transplantation is a life-threatening event. Previous reports have suggested that the resistive index (RI) of the hepatic artery predicts HAT. Doppler ultrasonography (US) to measure RI, however, is not routinely performed. The subjects were 70 pediatric patients who underwent living donor liver transplantation (LDLT). Protocol Doppler US was performed once or twice a day for 2 weeks postoperatively and 692 records were examined. Changes in RI values were examined separately in patients with and without HAT complications. The incidence of HAT was 10% (seven of 70). HAT was diagnosed an average of 6.2 days after LDLT. In patients without HAT complications ( n = 63), average RI levels at 14 days after LDLT were 0.71 +/- 0.1 (records, n = 625). In patients with HAT complications, RI decreased gradually within 2 days before the onset of HAT. RI values of less than 0.6 predicted HAT within 2 days before onset, with 83% sensitivity and 85% specificity. RI during the first 2 weeks after LDLT is a sensitive predictor for HAT. Thrombectomy and reanastomosis should be considered when RI values are less than 0.6 in Doppler US.

Adolescent↗
PubMed2004

Origin of magnetic and magnetoelastic tweedlike precursor modulations in ferroic materials.

Based on experimental observations of modulated magnetic patterns in a Co0.5Ni0.205Ga0.295 alloy, we propose a model to describe a (purely) magnetic tweed and a magnetoelastic tweed. The former arises above the Curie (or Néel) temperature due to magnetic disorder. The latter results from compositional fluctuations coupling to strain and then to magnetism through the magnetoelastic interaction above the structural transition temperature. We discuss the origin of purely magnetic and magnetoelastic precursor modulations and their experimental thermodynamic signatures.

Journal Article↗
PubMed2004

Living donor liver transplantation for end-stage hepatitis C.

Living donor liver transplantation is important for patients with end-stage viral hepatitis because of the shortage of organs from deceased donors. However, preliminary results indicate that living liver donation might be disadvantageous for hepatitis C virus-positive patients. Twenty-seven patients who underwent living donor liver transplantation for hepatitis C virus cirrhosis preemptively received antiviral therapy using interferon-alpha2b and ribavirin, which was started an average of 32 days after the operation and continued for at least 6 months thereafter. The serum hepatitis C virus RNA became negative in the 8 of 16 patients with more than 1 year follow-up. The cumulative 3-year patient survival was 85%, which was comparable to that of hepatitis C virus negative patients (n = 93; 90%). Preemptive antiviral therapy after transplantation may be necessary for satisfactory results after living donor liver transplantation.

Adult↗
PubMed2004

Effects of FTY720 on rat lymphoid organs.

INTRODUCTION: In this study, we examined the in vivo effect of FTY720 on rat thymus and spleen. MATERIALS AND METHODS: Inbred male Lewis (RT-I(l)) rats, 5-weeks-old, received FTY720 (0.1, 1, or 10 mg/kg) by intramuscular injection into 1 of 4 limbs daily for 7 days. The rats were humanely killed at 1, 3, 5, or 7 days after starting administration of FTY720. The thymus and spleen were obtained for hematoxylin and eosin (HE) as well as immunoperoxidase staining using the antibodies OX8 (CD8), W3/25 (CD4), and OX6 (major histocompatibility complex class II). RESULTS: HE staining revealed marked atrophy in the cortical region of the thymus among rats administered FTY720 at the dose of 10 mg/kg. The atrophy extended to the whole cortex. On day 7 of administration of FTY 720 (10 mg/kg), the medulla of the thymus showed relative expansion due to cells accumulation. Also, the spleens of FTY720-treated rats revealed an obvious reduction in the T-cell-dependent areas around the central artery. In conclusion, the immunosuppressive effect of FTY720 may be due to an inhibitory effect on T-cell emigration from the thymus to the periphery.

Animals↗
PubMed2004

Two cases of recurrent IgA nephropathy following kidney transplantation.

Recurrence of immunoglobulin (Ig) A nephropathy following kidney transplantation has been described as occurring in 40% to 60% of cases. Although this type of recurrence was considered a benign condition for a long time, more recent data showed that recurrent transplant IgA nephropathy may be a significant contributor to graft loss. We present 2 cases of recurrent IgA nephropathy following kidney transplantation. In case 1, renal function remained stable with a creatinine level of 1.2 mg/dL at 5 months after diagnosis and 61 months after transplantation. In case 2, the patient lost his graft and returned to regular hemodialysis at 36 months after diagnosis and 125 months after kidney transplantation.

Adult↗
PubMed2004

Classification of portal vein anatomy for partial liver transplantation.

The anatomy of the portal vein is usually classified as 3 to 5 patterns and simple compared with the anatomy of the hepatic artery. The variety of portal vein anatomy was examined in 287 living donors for liver transplantation. More than 90% of donors showed a normal bifurcation type; 6% showed the trifurcation type. Only 3% displayed a separate origin of the right paramedian and the right lateral branches. There was no anomalous pattern that had not been reported previously. In our series, we conclude that it is rare for 2 or more stumps of portal vein to appear in partial liver transplantation. The frequency is much less if the left liver or the right lateral liver graft is used for adult-to-adult living donor liver transplantation.

Functional Laterality↗
PubMed2004

Simultaneous hepatic artery and portal vein thrombosis after living donor liver transplantation.

Simultaneous hepatic artery and portal vein thrombosis rarely occurs after liver transplantation. The etiology is unknown. Of 213 patients (72 children and 141 adults) that underwent living donor liver transplantation (LDLT) from January 1996 to March 2003, 4 (2%) developed simultaneous thrombosis at 3 hours to 7 days (median, 4 days) after the operation. Emergent thrombectomy was performed in three patients; the remaining patient was registered in the Japan organ transplant network. All of the patients died due to hepatic failure (range, 18 hours to 6 days after the diagnosis; median, 2 days). Portal vein, hepatic artery, and hepatic vein velocity in the liver graft were measured every 12 hours by Doppler ultrasonography for 2 weeks after liver transplantation. These parameters were stable until just before the simultaneous thrombosis. These findings indicate that protocol Doppler ultrasonography can diagnose, but not predict, this fatal complication.

Adolescent↗
PubMed2004

Conversion to cyclosporine provides valuable rescue therapy for living donor adult liver transplant patients intolerant to tacrolimus: A single-center experience at the University of Tokyo.

Tacrolimus-based immunosuppression is currently accepted as mainstream therapy in many transplant centers worldwide due to its potent immunosuppressive activity compared to cyclosporine. A tacrolimus-based regimen has been successfully used for our living donor liver transplantation (LDLT) recipients. Adverse effects such as neurotoxicity, nephrotoxicity, and new-onset diabetes mellitus, however, have limited its clinical application. In deceased donor liver transplantation, cyclosporine rescue therapy is valuable for such complications, but few reports have described a strategy for conversion in LDLT. Herein, we present our experience of conversion from tacrolimus to cyclosporine therapy in adult LDLT recipients. Among 203 recipients, 37 patients (18%) required conversion, primarily for neurotoxicity (41%), diabetes mellitus (16%), hematopoietic disorder (16%), and gastrointestinal intolerance (11%). Primary adverse events resolved within 2 months after conversion in 35/37 (94%) of the patients. For LDLT recipients unable to maintain effective immunosuppression with tacrolimus, conversion to cyclosporine is an effective option.

Adult↗
PubMed2004

Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor.

To evaluate the feasibility of reduced intensity stem cell transplantation (RIST) with bone marrow from a matched unrelated donor (MUD), we retrospectively investigated 20 patients with hematological disorders who received RIST in the Tokyo SCT consortium from January 2000 to October 2002. The preparative regimens were fludarabine-based (150-180 mg/m(2), n=18) or cladribine-based (0.77 mg/kg, n=2). To enhance engraftment, antithymocyte globulin (ATG) and 4 or 8 Gy total body irradiation (TBI) were added to these regimens in nine and 11 patients, respectively. GVHD prophylaxis was cyclosporine with or without methotrexate. In all, 19 achieved primary engraftment. Three developed graft failure (one primary, two secondary), and five died of treatment-related mortality within 100 days of transplant. Seven of the 19 patients who achieved initial engraftment developed grade II-IV acute GVHD, and seven of 13 patients who survived >100 days developed chronic GVHD. At a median follow-up of 5.5 months, estimated 1-year overall survival was 35%. Compared with a TBI-containing regimen, an ATG-containing regimen was associated with a high risk of graft failure (30 vs 0%, P=0.0737). This study supports the feasibility of RIST from MUD; however, procedure-related toxicities remain significant in its application to patients.

Adult↗
PubMed2004

Reduced-intensity stem cell transplantation from an HLA-identical sibling donor in patients with myeloid malignancies.

The purpose of this study was to evaluate the feasibility and efficacy of allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen (RIST) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). In all, 36 patients (median age 55 years) underwent RIST from an HLA-matched related donor between September 1999 and December 2002. The diagnoses included AML (n=14), leukemia evolving from MDS (n=10), and MDS (refractory anemia with excess blasts n=6, refractory anemia n=6). The RIST regimen consisted of purine analog (cladribine or fludarabine)/busulfan, with or without antithymocyte globulin. The regimen was well tolerated, and 34 patients achieved durable engraftment and most achieved remission after RIST. A total of 17 patients developed grade II-IV acute GVHD, and 27 developed chronic GVHD. Eight patients relapsed, and five of them received antithymocyte globulin (ATG) as part of the preparative regimen. A total of 12 patients died (four disease progression, six transplantation-related complications, and two others). Estimated 1-year disease-free survival (DFS) in low- and high-risk groups was 85 and 64%, respectively. We conclude that RIST can be performed safely in elderly patients with myeloid malignancies, and has therapeutic potential for those who fail conventional chemotherapy. In view of the significant association between GVHD or ATG and DFS, defined management of GVHD following RIST should become a major target of clinical research.

Adult↗
PubMed2004

Regimen-related toxicity following reduced-intensity stem-cell transplantation (RIST): comparison between Seattle criteria and National Cancer Center Common Toxicity Criteria (NCI-CTC) version 2.0.

Acute regimen-related toxicity (RRT) is minimal in reduced-intensity stem-cell transplantation (RIST). However, the Seattle RRT grading (Bearman et al), developed in the context of conventional-intensity transplantation, is frequently applied to RIST. We compared the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2.0 with the Seattle criteria after RIST in 86 patients. RRT within 30 days of transplant graded by both sets of criteria were significantly associated with the outcome confirming the predictive value of both the systems. A total of 15 patients died of disease progression, and 12 of transplant-related mortality: RRT (n = 2), graft-versus-host disease (GVHD) (n = 7), infection (n = 1), and others (n = 2). GVHD-related deaths primarily resulted from infections after steroid treatment (n = 6) and bronchiolitis obliterans (n = 1). This study shows that NCI-CTC is appropriate in toxicity evaluation of RIST, and that its application to RIST enables a toxicity comparison between RIST and other types of cancer treatments. Since GVHD is a significant problem in RIST, modifications are required to evaluate immunological complications following RIST.

Graft vs Host Disease↗
PubMed2004

T-bet upregulation and subsequent interleukin 12 stimulation are essential for induction of Th1 mediated immunopathology in Crohn's disease.

BACKGROUND AND AIMS: Many lines of evidence suggest that T helper cell type 1 (Th1) immune responses predominate in Crohn's disease (CD). Recently, a novel transcription factor T-box expressed in T cells (T-bet) has been reported as the master regulator of Th1 development. This study was designed to investigate the role of T-bet and proinflammatory cytokines in Th1 mediated immunopathology in CD. MATERIALS: CD4+ lamina propria mononuclear cells (LPMCs) were isolated from surgically resected specimens (CD, n = 10; ulcerative colitis (UC), n = 10; normal controls (NL), n = 5). METHODS: (1) T-bet expression of CD4+ LPMCs was examined by quantitative real time polymerase chain reaction and western blotting. (2) T-bet expression of LPMCs stimulated by interleukin (IL)-12/IL-18 was analysed by western blotting. (3) Interferon gamma (IFN-gamma) production and T-bet expression of CD4+ peripheral blood mononuclear cells (PBMCs) were examined with or without stimulation by anti-CD3/CD28 monoclonal antibodies and/or IL-12. RESULTS: (1) T-bet expression of CD4+ LPMCs was increased in CD compared with UC and NL. (2) Synergistically, augmentation of IFN-gamma production by IL-12/IL-18 was independent of T-bet expression in LPMCs. (3) T-bet was induced by T cell receptor stimulation in CD4+ PBMCs. T-bet induction correlated with IFN-gamma production and with augmentation of surface expressed IL-12 receptor beta2. CONCLUSIONS: T-bet induction by antigenic stimulation and subsequent stimulation by macrophage derived IL-12/IL-18 are important for establishing Th1 mediated immunopathology in CD.

Adult↗
PubMed2003

Duct-to-duct biliary reconstruction for living donor liver transplantation: experience of 92 cases.

Bile duct-to duct reconstruction is now performed in living donor liver transplantation (LDLT) for adult patients. To confirm the feasibility, the results after the reconstruction were retrospectively analyzed. The subjects were 92 adult patients who underwent LDLT at the University of Tokyo Hospital. During the observation period (median 546 days), biliary complications were observed in 28 cases (30%). The complications included bile juice leakage in 11, stenosis at the anastomotic site in 9, and tube trouble in 8. Of these, 20 patients required surgical revision. The results suggest that duct-to-duct reconstruction provides satisfactory results, although long-term observation will be necessary.

Bile Ducts↗