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Tomomi Suzuki

Publications and source records attributed to Tomomi Suzuki.

31 records · Page 2Linked to original sources
PubMed2004

[Liver regeneration in living-donor liver transplantation].

Liver regeneration in living-donor liver transplantation is summarized from the authors' data. In donors, liver function tests recovered to within the normal range 2 weeks after surgery regardless of graft type. At 2 weeks, the volumetric recovery of the remnant liver was 65% and 80% of the original volume in right and left lobe donors, respectively. These results suggest that functional recovery occurs earlier than morphologic restoration in donors. In recipients, the factor that affected the regeneration rate in size 4 weeks after transplantation was only implanted graft size; the rate was greater in patients in whom smaller grafts were implanted. In recipients with a rate of two or more, however, high portal vein pressure and flow were observed. Further, persistent low platelet counts and hyperbilirubinemia were seen in those patients. These results indicate that size enlargement may be caused by engorgement, and functional recovery is not achieved concurrently with morphologic restoration, especially in patients with smaller grafts. In patients with fulminant hepatic failure who receive auxiliary partial orthotopic liver transplantation, sequential histopathologic observations of the diseased liver revealed that liver regeneration initiates from cytokeratin 17-positive ductules and at least 1 year is necessary for complete recovery.

Hepatocytes↗
PubMed2003

The impact of donor chemical overdose on the outcome of liver transplantation.

BACKGROUND: To overcome the critical shortage of liver grafts, many centers have been widening the acceptance criteria for liver donation. Use of liver grafts from victims who have suffered chemical overdose (COD) may be one option that could help to expand the donor pool. However, this practice has been poorly documented. METHODS: Of 1,195 orthotopic liver transplantations performed at our institution between June 1994 and March 2001, 22 involved livers (1.8%) were retrieved from COD donors. Donor and recipient characteristics and posttransplantation outcomes were analyzed retrospectively. RESULTS: The main chemicals causing brain death of the donor were carbon monoxide (n=4), cocaine (n=4), tricyclic antidepressants (n=3), 3,4-methylenedioxy- methamphetamine (n=2), opiates (n=2), aspirin (n=1), gamma hydroxybutyrate (n=1), heroin (n=1), insulin (n=1), verapamil (n=1), barbiturate (n=1), and brompheniramine/phenylpropanolamine (n=1). Primary nonfunction developed in one patient who had received a liver from an 3,4-methylenedioxymethamphetamine-intoxicated donor. Another patient died of fungal meningitis 10 days after transplantation with a functioning graft. The remaining 20 patients experienced acceptable early graft function, as demonstrated by initial mean peak values of bilirubin (4.8 mg/dL), aspartate aminotransferase (624 U/L), and alanine aminotransferase (730 U/L). One-year graft survival rate estimated by the Kaplan-Meier method was 86%. CONCLUSIONS: Satisfactory outcomes of graft function were achieved in orthotopic liver transplantations from COD donors. The cautious use of liver grafts from selected COD donors may be a worthwhile method of increasing the availability of scarce donor organs.

Adolescent↗
PubMed2003

Neuroradiologic and clinical abnormalities in dementia of diffuse neurofibrillary tangles with calcification (Kosaka-Shibayama disease).

We describe a characteristic dementia patient diagnosed as diffuse neurofibrillary tangles with calcification (DNTC). Neuropsychologically, dementia, including a decline in memory retention and intelligence, and anomic aphasia were recognized. Imaging revealed circumscribed temporal dominant atrophy and calcification of the basal ganglia and cerebellum. SPECT and FDG-PET revealed a remarkable reduction of blood flow and metabolism in the temporal lobes; however, there is no reduction in the basal ganglia and cerebellum, and FDOPA-PET also disclosed no abnormalities. This suggests that calcification and neuronal degeneration occur independently in DNTC.

Aged↗
PubMed2003

A novel inhibitor of Rho-associated protein kinase, Y-27632, ameliorates hepatic ischemia and reperfusion injury in rats.

BACKGROUND: A Rho-ROCK signal system induces vascular contraction and neutrophil migration, both of which are characteristic features found with ischemia and reperfusion injury of the liver. We tested our hypothesis that a novel ROCK I inhibitor, Y-27632, attenuates hepatic ischemia and reperfusion injury. METHODS: Rats underwent 70% partial hepatic ischemia for 120 minutes and subsequent reperfusion. Y-27632 of 10mg/kg was given orally 1 hour before ischemia, while distilled water was given to the control animals. One week animal survival, systemic hemodynamics, hepatic tissue blood flow, liver function tests, plasma endothelin-1, serum hyaluronic acid levels, myeloperoxidase activity and malondialdehyde level in liver tissue, membrane attack complex-1 and intracellular adhesion molecule-1 staining, and histological architecture were analyzed. RESULTS: Y-27632 prolonged 1-week animal survival from 25% of untreated animals to 75% accompanied with significant amelioration of hepatic tissue blood flow, liver function tests and histological architecture without any adverse effects on systemic hemodynamics. In addition, plasma endothelin-1 and serum hyaluronic acid levels decreased markedly compared to the control, concomitant with remarkable suppression of membrane attack complex-1 stain positive neutrophils infiltration, myeloperoxidase activity and malondialdehyde level. CONCLUSION: Present study suggests that activation of a Rho-ROCK signal system is associated with ischemia and reperfusion injury of the liver, and that Y-27632 may be an attractive agent for application in major liver resection using temporary inflow occlusion and hepatic preservation.

Alanine Transaminase↗
PubMed2003

Extracellular matrix disturbances in acute myocardial infarction: relation between disease severity and matrix metalloproteinase-1, and effects of magnesium pretreatment on reperfusion injury.

PURPOSE: The purpose of this paper is to clarify the relationship between cytokines, matrix metalloproteinase-1 (MMP-1) and severity of acute myocardial infarction (AMI). Additionally, to investigate whether magnesium (Mg) sulfate pretreatment inhibits myocardial damage in coronary reperfusion therapy for patients with AMI. SUBJECTS: At first, 34 patients with AMI were enrolled. Then, the patients were classified into 2 groups with or without congestive heart failure (CHF) (C group and NC group, respectively). Interleukin 6 (IL-6), MMP-1 and the hemodynamic parameters were measured. Second, 36 AMI patients treated with coronary reperfusion therapy were enrolled. Patients were divided into 2 groups (18 patients each) as the non-pretreated group (Control group) and the group pretreated with intravenous Mg sulfate (0.27 mmol/kg) (Mg group). IL-6, MMP-1 and the indexes of reperfusion injury were evaluated. RESULTS: There were positive correlations between peak MMP-1 level, and peak creatine kinase value and pulmonary capillary wedge pressure and peak IL-6 level (r = 0.43, r = 0.70, and r = 0.60, respectively) in all patients. There were negative correlations between peak MMP-1 level and left ventricular ejection fraction and cardiac index (r = - 0.52 and r = - 0.55, respectively). The peak blood IL-6 and MMP-1 level increased in AMI, particularly in patients with CHF (C group vs NC group; 130 vs 51 pg/mL and 37 vs 18 ng/mL, both p < 0.01). Additionally, peak IL-6 and peak MMP-1 in the Mg group were lower than those of the control group (39 vs 92 pg/mL and 16 vs 20 ng/mL, p < 0.05 and p = 0.09, respectively). The incidence of reperfusion injury including reperfusion arrhythmia and transient exacerbation of ST elevation in the Mg group was lower than that of control group (17 vs 78% and 2.5 vs 4.7 mm, p < 0.01 and p = 0.08, respectively). CONCLUSION: These results may suggest that the severity of AMI is reflected by the blood IL-6 and MMP-1 levels and that pretreatment with Mg administration protects the myocardium of patients with AMI from reperfusion injury induced by IL-6 and MMP-1.

Aged↗
PubMed2002

Role of cyclic nucleotides in ischemia and reperfusion injury of canine livers.

BACKGROUND: In a series of canine liver ischemia experiments, we have shown that amelioration of hepatic injury is achievable by the inhibition of vasoconstriction, cytokine production, platelet aggregation, and neutrophil infiltration. Cyclic adenosine diphosphate (cAMP) was considered to be involved in most of these events. In our study, we tested our hypothesis that augmentation of endogenous cAMP by phosphodiesterase (PDE) 3 inhibitor, amrinone (AM), or adenylate cyclase stimulator, NKH477 (NKH), could attenuate ischemia and reperfusion injury of the liver. METHODS: Thirty-six beagle dogs were used. They were divided into group CT (untreated control), group AM, group NKH, and group CB (treated by both agents). AM or NKH were administered i.v. 1 hr before ischemia (group preAM and group preNKH) or 15 min before reperfusion (pos-AM and postNKH). Combination group animals were treated only before ischemia. Animal survival, hepatic tissue blood flow, liver enzymes, platelet counts, energy metabolism, hepatic cAMP and cyclic guanosine 3',5'-cyclic monophosphate levels, and histopathology were analyzed. RESULTS: Two-week animal survival was significantly improved by pre- or posttreatment with either agent. After reperfusion, hepatic tissue blood flow, liver enzyme release, platelet counts, energy metabolism, tissue cAMP levels, and histological architecture were also ameliorated markedly. Combination of both agents induced severe liver damage and lethal hypotension. AM treatment exhibited more protective effects than NKH, particularly when it was given before ischemia. Interestingly, not only cyclic guanosine 3',5'-cyclic monophosphate, were also restored at higher levels after reperfusion by preischemia treatment. CONCLUSIONS: Administration of amrinone or NKH477 maintained hepatic tissue concentrations of cyclic nucleotides, and attenuated ischemia and reperfusion injury of the liver. Thus, regulation of hepatic tissue cyclic nucleotides is an important alternative for prevention of hepatic damage in liver preservation and surgery.

Adenosine Triphosphate↗
PubMed2002

A novel leflunomide derivative, FK778, for immunosuppression after kidney transplantation in dogs.

BACKGROUND: Leflunomide and its metabolite, A77 1726, interfere with pyrimidine metabolism and exert potent immunosuppression in experimental organ transplantation. However, clinical use of the agents has been restrained because of an extended half-life. FK778, one synthetic malononitrilamide derived from A77 1726, is synthesized to overcome this problem while maintaining similar therapeutic efficacy. METHODS: Immunosuppressive effect, pharmacokinetics, and adverse events of FK778, as a single drug treatment or combination with tacrolimus or cyclosporine, were determined in a canine kidney transplantation model. The agents were daily administered orally to the animals for 90 days after surgery. Animal survival, pharmacokinetics, biochemistry, hematology, and histopathology were evaluated. RESULTS: FK778 at 4 mg/kg prolonged median survival of the control animals from 10 days to 30.5 days. Administration of 4 mg/kg FK778 with 0.3 mg/kg tacrolimus or 10 mg/kg cyclosporine increased median survival to 75.5 days and 50.5 days, respectively. In combined treatments, trough levels of FK778 at 4 mg/kg ranged between 40 microg/mL and 100 microg/mL after 1 month. Vomiting and diarrhea were common in animals given FK778. Bone marrow suppression was seen at higher doses. CONCLUSIONS: FK778 is a promising new immunosuppressant that may be used in combination with current standard drugs in organ transplantation.

Alkynes↗
PubMed2002

An Arabidopsis histidine-containing phosphotransfer (HPt) factor implicated in phosphorelay signal transduction: overexpression of AHP2 in plants results in hypersensitiveness to cytokinin.

Histidine-containing phosphotransfer (HPt) factors from Arabidopsis thaliana, designated as AHPs, function most likely in concert with histidine (His)-kinases (HKs) and response regulators (RRs) in certain multistep histidine (His)-->aspartate (Asp) phosphorelays that are involved in the signal transduction mechanisms, by which plant cells appear to respond to certain hormonal stimuli, including cytokinin. Although some previous in vitro results from studies on Arabidopsis AHPs (AHP1 to AHP5) supported this hypothesis, it has not yet been proven. To this end, here we constructed transgenic plants that contained the AHP2 protein in a considerably higher amount than in wild-type plants. Such AHP2-overexpressing young seedlings were examined in comparison with wild-type plants, with special reference to hormone responses; particularly, their inhibitory effects on root elongation of plants grown on agar-plates, and also hypocotyl elongation of etiolated seedlings grown in the dark. The results of this study suggested that AHP2-overexpressing plants showed a characteristic phenotype of cytokinin-hypersensitive. These in vivo observations were best interpreted by assuming that the AHP factor(s) is somehow implicated, if not directly, in a cytokinin-mediated His-->Asp phosphorelay signaling in Arabidopsis.

Arabidopsis↗
PubMed2002

[Liver transplantation for patients with hepatitis B/C virus cirrhosis or hepato cellular carcinoma].

The outcome of liver transplantation for patients with hepatitis B/C virus (HBV/HBC) cirrhosis or with hepatocellular carcinoma(HCC) was deemed pessimistic until the early 1990s due to the high rate of recurrence and mortality. However, with the advent of new antiviral agents and strict adherence transplant indications, the results of liver transplantation in patients with these disease have improved progressively. Coadministration of lamivudine and anti-HBV immunoglobulin, and of interferon and ribavirin inhibits the recurrence of hepatitis B and hepatitis C, respectively. Excluding HCC patients with extrahepatic or lymph node metastasis, vascular invasion, a single lesion more than 5 cm in diameter, or multiple lesions more than 3 cm in diameter, the 5-year patient survival rate has improved from 30% to 85%, with a disease-free survival rate of more than 90%. However, the development of lamivudineresistant mutants after prolonged use of the agent needs to be overcome, possibly by new antiviral agents such as adefovir. In addition, to expand the current limited transplant indications for HCC, the efficacy of perioperative anticancer treatment and the importance of molecular diagnosis of circulating hepatoma cells must be determined in future.

Adult↗