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Y Inomata

Publications and source records attributed to Y Inomata.

At least 37 records · Page 2Linked to original sources
PubMed2001

Determination of hydrogen peroxide by iron(III) complex of thiacalix[4]arenetetrasulfonate on a modified ion-exchanger with peroxidase-like catalytic activity.

An iron(III) complex of thiacalix[4]arenetetrasulfonate on a modified anion-exchanger (Fe3+-TCAS(A-500)) has shown high peroxidase-like activity at pH 5 - 6 for the reaction of quinoid-dye formation between 3-methyl-2-benzothiazolinone hydrazone and N-(3-sulfopropyl)aniline in the presence of hydrogen peroxide. Utilizing the peroxidase-like activity of Fe3+-TCAS(A-500) for this reaction, a method using Fe3+-TCAS(A-500) was applied for the spectrophotometric determination of hydrogen peroxide. The calibration curve by the method using Fe3+-TCAS(A-500) was linear over the range from 1 to 10 microg of hydrogen peroxide in a 1 ml sample solution. The apparent molar absorptivity for hydrogen peroxide was 2.4 x 10(4) l mol(-1) cm(-1). which was about 80% of that by peroxidase under the same conditions. This determination method of hydrogen peroxide using Fe3+-TCAS(A-500) was applied for the determination of glucose in diluted normal and abnormal control serum I and II.

Calibration↗
PubMed2001

The efficacy of prevascularization by basic FGF for hepatocyte transplantation using polymer devices in rats.

This study used polymer devices implanted in rats to investigate the effect of prevascularization by basic fibroblast growth factor (bFGF) on hepatocyte transplantation (HTx). Lewis rats served as both donors and recipients. Polyvinyl alcohol (PVA) sponges with either hydrogel containing bFGF (bFGF group) or distilled water (control group) were implanted between the mesenteric leaves of recipient rats. Hepatotrophic stimulation was induced by a portacaval shunt and a 70% partial hepatectomy. After 1 week of prevascularization, hepatocytes harvested from the donor Lewis rats using a collagenase digestive method were injected into the sponges. Specimens were harvested at 2 weeks, 1 month, and 2 months after HTx. Histologic examination revealed that the control groups contained small numbers of hepatocytes restricted to the peripheral areas of the sponges. However, a large number of hepatocytes, including clusters, was found distributed uniformly in the bFGF group. In the bFGF group at 2 weeks, 1 month, and 2 months, the percentage of the sponge occupied by hepatocytes was 7.21+/-2.64%, 6.98+/-2.59%, and 5.58+/-3.77%, respectively. The corresponding ratios for the control group were 0.40+/-0.39%, 0.40+/-0.40%, and 0.87+/-1.51%. In addition, the mean number of new blood vessels in the bFGF group was significantly greater than that in the control group at 0 days, 2 weeks, and 1 month after HTx. These results suggest that bFGF strongly induced vascularization, which enabled a large number of hepatocytes to survive in the polymer devices.

Animals↗
PubMed2000

Living donor liver transplantation for fulminant hepatic failure.

BACKGROUND: Living donor liver transplantation (LDLT) was originally indicated only for elective cases of pediatric patients with end-stage liver disease. In Japan, however, where liver transplantation from brain-dead donor is performed very rarely, this indication has been expanded to emergency cases such as fulminant hepatic failure (FHF). METHODS: Thirty-eight patients with FHF were treated between May 1992 and April 1999. Causes of acute liver failure were non-A, non-B hepatitis in 27 patients, hepatitis B virus in seven, and hepatitis A virus, Epstein-Barr virus, herpes simplex virus, and chrome poisoning in one each. RESULTS: Four patients did not undergo LDLT because of severe brain damage or combined multiple organ failure. The remaining 34 patients underwent a total of 36 LDLTs, including two retransplantations; 16 children received transplants of 17 lateral segments, three children and eight adults transplants of 11 left lobes, and seven adults transplants of eight right lobes. A total of 15 recipients died, four of primary graft dysfunction, three of refractory acute rejection, two of pneumonia, and one each of ductopenic rejection, sepsis, aplastic anemis, recurrence of Epstein-Barr virus hepatitis, multiple organ failure by chrome poisoning, and unknown hepatic failure. Primary graft dysfunction developed in adult recipients with small-for-size graft transplants, whereas refractory acute rejection and ductopenic rejection occurred in six grafts each of children with non-A, non-B FHF. CONCLUSIONS: LDLT can be safely expanded to cases of FHF in adult patients. Primary graft dysfunction in adult recipients with small-for-size left lobe grafts can be overcome by using right lobes. However, refractory acute rejection and ductopenic rejection in children remain a major problem.

Adolescent↗
PubMed2000

Tacrolimus and myocardial hypertrophy.

Tacrolimus has been used as an immunosuppressive agent in the transplantation of all solid organs. Tacrolimus-induced hypertrophic cardiomyopathy has been reported to be an unusual but serious complication. To elucidate the effects of tacrolimus on myocardial hypertrophy, we studied the relationship between the blood levels of tacrolimus and cardiac wall thickening. Our findings demonstrated that tacrolimus-induced myocardial hypertrophy correlated with tacrolimus blood levels, and that myocardial hypertrophy induced by tacrolimus was reversible. However, no patients developed clinically significant symptoms related to myocardial hypertrophy.

Adolescent↗
PubMed2000

Right lobe graft in living donor liver transplantation.

BACKGROUND: For the sake of donor safety in living donor liver transplantation (LDLT), the left lobe is currently being used most often for the graft. However, size mismatch has been a major obstacle for an expansion of the indication for LDLT to larger-size recipients, because a left lobe graft is not safe enough for them. METHODS: In 1998, LDLT using a right lobe graft was introduced and performed on 26 recipients to overcome the small-for-size problem. The right lobe, which does not include the middle hepatic vein of the donor, was used. Initially, indication for right lobe LDLT was basically defined as an estimated left lobe graft volume/recipient body weight ratio (GRWR) of <0.8%, which was later raised to <1.0%. RESULTS: All the donors recovered from the operation without persistent complications. Two donors with transient bile leakage were successfully treated with a conservative approach. A right lobectomy resulted in more blood loss (337+/-175 ml), and a longer operative time (6.67+/-0.85 hr) than a lateral segmentectomy, but not a left lobectomy. Grafts with a GRWR >0.8% were implanted in all recipients, except for two, who received relatively smaller right lobes (GRWR of 0.68% and 0.66%). In one of these two, the right lobe from the donor was used as the orthotopic auxiliary graft. Postoperative transitory increases in total bilirubin and aspartate transaminoferase for right lobe donors were higher than those for the left lateral segmentectomy. Nineteen recipients (73.1%) were successfully treated with this procedure. The causes of death were not specific for right lobe LDLT, except for one patient with a graft that had multiple hepatic venous orifices. These multiple and separate anastomoses of the hepatic veins caused an outflow block as a result of a positional shift of the graft, which finally led to graft loss. CONCLUSION: Our experience suggests that right lobe grafting is a safe and effective procedure, resulting in the expansion of the indication for LDLT to large-size recipients. How to deal with the possible variation in the anatomy of the right lobe graft should be given attention throughout the procedure.

Adolescent↗
PubMed2000

Small bowel transplantation using grafts from living-related donors. Two case reports.

A living-related small bowel transplantation (SBT) was performed in two pediatric patients with short bowel syndrome. In both cases, the donor was the patient's mother. The distal ileum (100 cm, 120 cm) was harvested and the ileocolic vessels, ileocecal valve, and terminal ileum were left intact. The two donors were discharged from the hospital on postoperative days 15 and 6, respectively. Recipient 1 was a 2 year 6 month-old boy with short bowel syndrome who underwent SBT due to loss of venous access. The graft vein was anastomosed to the recipient's infrarenal inferior vena cava. Despite triple immunosuppression (tacrolimus, steroid, and azathioprine), there were four episodes of rejection. The patient had been on total parenteral nutrition for almost his entire posttransplant course. He died from Pneumocystis carinii pneumonia 16 months after the transplantation. Recipient 2 was a 4 year 5 month-old girl with short bowel syndrome who underwent an isolated small bowel transplantation because of recurrent line sepsis. Her pretransplant bilirubin was 8.0 mg/dl and a biopsy showed severe fibrosis. The graft vein was anastomosed to the recipient's inferior mesenteric vein. After transplantation, her bilirubin level became normal within 10 days. Triple immunosuppression (tacrolimus, steroid, and cyclophosphamide) together with a 3-day course of OKT-3 made her post-transplant course feasible. After overcoming a single episode of rejection she left the hospital 4 months after SBT. The patient is currently (10 months after transplantation) hospitalized due to rejection, which is being successfully controlled, and she is off total parenteral nutrition. From our experience, harvesting of the distal ileum for use as a bowel graft can be safely performed. The advantages of living-related grafts, optimal graft length, and choice of vascular reconstruction in SBT are yet to be explored.

Adult↗
PubMed2000

Hepatic grafts from live donors: donor morbidity for 470 cases of live donation.

Living donor-morbidity was evaluated in 470 consecutive cases of living donor liver transplantation carried out from June 1990 to May 1999 at Kyoto University. Grafting was categorized into 4 groups according to the resection lines; left lateral segmentectomy (S2 + 3, n = 282, R1), extended left lateral segmentectomy without middle hepatic vein (MHV) (S2 + 3 + part4, n = 45, R2), left lobectomy with MHV (S2 + 3 + 4, n = 99, R3) and right lobectomy without MHV (S5 + 6 + 7 + 8, n = 43, R4). Intraoperative blood loss and operation duration were less for left lateral segmentectomy, but no significant difference was observed between left lobectomy and right lobectomy. The length of postoperative hospital stays was comparable among all groups except for the group with right lobe grafting. The AST values at the peak and at POD 7 were significantly elevated for right lobectomy, but the AST value normalized within one month in the majority of the cases. The close follow-up of donors with more than 1,000 ml intraoperative bleeding, and of those donors who stayed in hospital for more than 30 days, the close follow-up, furthermore, of those donors with AST values higher than 100 IU/ L AST after one month, revealed complete recovery. Biliary leakage was the most common and annoying complication after donor operations, especially in for right lobe grafting, but all donors recovered completely with conservative or minimal invasive therapy. The two cases of re-operation due to adhesive mechanical ileus we encountered were resolved completely. Finally, no donor-operation related death was noted. In conclusion, the morbidity of living donors is low or minimal even for right lobectomy, the most extended procedure, and complete recovery can be expected in all cases.

Adult↗
PubMed2000

Effect of intestinal P-glycoprotein on daily tacrolimus trough level in a living-donor small bowel recipient.

We have examined whether the expression levels of the intestinal absorptive barriers, MDR1 gene product P-glycoprotein and cytochrome P450 IIIA4 (CYP3A4), correlate with the trough levels of orally administered tacrolimus in a recipient of small bowel transplant for 4 months. By using a competitive polymerase chain reaction, the expression of MDR1 messenger RNA (mRNA) and CYP3A4 mRNA by intestinal cells in a part of the mucosa biopsy specimen was evaluated. The average mRNA expression levels of MDR1 and CYP3A4 were 8.6 and 39.6 amol/microg total RNA, respectively. Both the MDR1 and CYP3A4 mRNA levels changed markedly throughout this period. The tacrolimus concentration/dose ratio correlated well with the mRNA expression level of MDR1, but not CYP3A4. These results suggested that intestinal P-glycoprotein rather than CYP3A4 is a good probe to predict the intraindividual variation in the tacrolimus pharmacokinetics during immunosuppressant therapy after small bowel transplantation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Simultaneous measurement of volatile sulfur compounds using ascorbic acid for oxidant removal and gas chromatography-flame photometric detection.

A method for the simultaneous measurement of volatile sulfur compounds (COS, H2S, CS2, CH3SH, DMS) is established with preconcentration and GC-flame photometric detection (FPD). Prior to preconcentration of ambient air, it was necessary to remove SO2, water vapor and atmospheric oxidant. SO2 and water vapor were removed using a glass fiber filter and a cooled PTFE water trap loop, respectively. In order to remove atmospheric oxidant, the efficiency of an ascorbic acid scrubber was examined. It was found that an ascorbic acid scrubber enabled measurement of volatile sulfur compounds without adsorption and reaction loss. The detection limits for COS, H2S, CS2, CH3SH and DMS were 20, 34, 35, 263 and 44 pg of S, respectively.

Air↗
PubMed1999

Living related liver transplantation from donors with the left-sided gallbladder/portal vein anomaly.

The presence of a left-sided gallbladder poses a unique challenge for living related liver donation. Associated anomalies include segment IV atrophy, absence of portal vein bifurcation, and abnormal intrahepatic portal branches to segments II and III. The complex is rare, but is more frequent in Japan. Of 379 living related liver transplants from our institution, the complex has been encountered on four occasions (incidence: 1.1%), and we herein review our experience. Anomalies were identified preoperatively (by computed tomography and ultrasound) in all instances. One donor was turned down because there was no common portal trunk to segment II and III branches. Three donors underwent successful retrieval using a modified technique. There were no complications in the donors or recipients relating to the complex. Thus, living related liver retrieval can be achieved safely in the presence of the left-sided gallbladder/portal anomaly complex, but technical modifications are required.

Adolescent↗
PubMed1999

Auxiliary partial orthotopic living donor liver transplantation as an aid for small-for-size grafts in larger recipients.

BACKGROUND: In countries where living donors are the only source of liver grafts, restrictions on graft size are a serious obstacle for the expansion of indications for adult recipients. To overcome this problem, auxiliary partial orthotopic liver transplants (APOLT*) was performed on the basis of the concept that the residual native liver would support the graft function until the graft had grown enough to function by itself. METHODS: APOLT as an aid for small-for-size (SFS) grafts was reviewed retrospectively to evaluate its feasibility. Between April 1995 and March 1998, 20 recipients underwent APOLT, which was indicated because of a SFS graft in 15 of them. The indication was based on the estimated graft/recipient's body weight ratio (GRWR). If the ratio was <0.8%, APOLT was performed. The other 5 patients had a graft with a GRWR >0.8% and underwent APOLT on the basis of the residual native liver supporting the graft function temporarily, 4 for supplementation of the defective enzyme in metabolic liver diseases and one for leaving the potential of the regeneration of the native liver in fulminant hepatic failure. The recipients who underwent APOLT because of a SFS graft were categorized as the SFS group, and the others were the second group. RESULTS: In the SFS group, the age of the recipients ranged from 13 to 48 (median 23). The original indications of this group were fulminant hepatic failure in 2 recipients, acute deterioration of chronic liver diseases in 3, Wilson's disease in 2, biliary atresia in 4, primary biliary cirrhosis in 3, and primary sclerosing cholangitis (PSC) in one. The actual GRWR ranged from 0.45 to 0.72 (median 0.55). The graft was implanted after resection of the left lateral segment of the native liver. Except in the first two patients, the portal vein to the residual native liver was completely transected so that all of the portal blood drained into the graft liver. This procedure was successful in 9 patients. The cause of death in the other 6 was mainly infection. The mortality rate among the recipients with signs of advanced liver failure, such as massive ascites or hepatic coma, was higher, even though APOLT was used to support the SFS graft. In the second group, in the other five recipients who underwent APOLT for other indications, one recipient with fulminant hepatic failure died of sepsis caused by the dehiscence of bilio-enteric anastomosis. CONCLUSIONS: APOLT as an aid for a SFS graft is technically viable. This procedure can thus expand the indication of living donor liver transplants for adult recipients when the native liver retains some functional capability to support the grafted liver during the immediate postoperative period.

Adolescent↗
PubMed1999

Long-term outcome of living related liver transplantation for patients with intrapulmonary shunting and strategy for complications.

BACKGROUND: In 320 living related liver transplantation performed between June 1990 and September 1997, there were 21 living related liver transplantation for patients with intrapulmonary shunting, manifested by digital clubbing, cyanosis, and dyspnea. We report the long-term outcome for more 6 months and our strategy to overcome complications in these recipients. PATIENTS: A total of 21 patients (age range 2-33 years, 19 children and 2 adults, 6 males and 15 females) were classified into three grades according to shunt ratio calculated by TcMAA pulmonary scintigraphy; 5 in mild group (shunt ratio: less than 20%), 6 in moderated group (20%-40%), and 10 in severe group (more than 40%). The original underlying liver disease was biliary atresia in all patients. RESULTS: Spearmen's correlation coefficient rank test revealed that shunt ratio correlated significantly with PaO2 in room air (P=0.0001), PaO2 in 100% oxygen (P=0.0004), hematocrit (P=0.0276), and period of dyspnea before transplantation (P=0.023). COMPLICATIONS: Wound infection occurred in 80, 66, and 80%, and bile leakage in 20, 0, 40% in mild, moderate, and severe group, respectively. Patients who had portal vein thrombosis, and intracranial complication were classified as severe group and the incidence was 20 and 20%, respectively. The patient actuarial one year survival was 80, 66.7, and 48%, in mild, moderate, and severe group, respectively, although there was no significant difference. All patients who survived improved hepatopulmonary syndrome and the length of period required for the resolution was significantly correlated to the preoperative shunt ratio (P=0.023). COMMENTS: Patients with severe shunting are susceptible to wound infection and bile leak. The trend of higher incidence of portal thrombosis and intracranial complications in the severe group was closely related high hematocrit. Secure surgical technique to reduce bile leak and delayed primary wound closure to reduce wound infection were found to be effective. Anticoagulant therapy by infusing heparin through the portal vein followed by coumadin could prevent fatal portal vein thrombosis without counter risk of fatal cerebral hemorrhage.

Adolescent↗
PubMed1999

Postoperative flow cytometry crossmatch in living donor liver transplantation: clinical significance of humoral immunity in acute rejection.

BACKGROUND: The role of humoral immunity in acute rejection in solid organ transplantation remains controversial, although it is known that the presence of antidonor antibodies may precipitate graft rejection. We investigated the clinical relevance of antidonor humoral immunity for living donor liver transplantation (LDLT) by means of flow cytometry crossmatch (FCXM). METHODS: T cell FCXM using fresh donor peripheral lymphocytes was performed before and up to 1 month after LDLT in 58 patients. Ten patients received ABO-incompatible grafts. IgM and IgG antidonor antibodies were analyzed in relation to clinical acute rejection as defined by liver function tests with or without histological evidence. RESULTS: Pretransplantation FCXM was positive for five patients (8.6%), resulting in two cases of positive posttransplantation FCXM and two rejection episodes. Twelve patients (20.7%) showed positive posttransplantation FCXM. The incidence of acute rejection within 1 month was 100% in FCXM-positive patients and 17.4% in FCXM-negative patients (P<0.001). Thirteen (76.5%) of 17 rejection episodes in ABO-compatible cases were associated with concomitant antidonor IgM antibody. IgG antibody was also identified in six of these episodes. Antidonor antibodies disappeared after rejection treatments in all cases, but with some delay in clinical improvement. On the other hand, no antidonor antibodies were detected in any of the four rejection episodes in ABO-incompatible cases. CONCLUSIONS: Early acute rejection in LDLT is significantly associated with antidonor T cell antibody formation in ABO-compatible cases. This suggests a definite role for donor-specific humoral immunity in acute rejection. Rejection episodes without antidonor antibodies may suggest graft injury by pure cellular immunity, or possibly the presence of humoral immunity triggered by antigens not present on donor T cells.

ABO Blood-Group System↗