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Dive into the research topics where Masato Fujiki is active.

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Featured researches published by Masato Fujiki.


American Journal of Transplantation | 2010

Use of tissue plasminogen activator in liver transplantation from donation after cardiac death donors.

Koji Hashimoto; Bijan Eghtesad; Ganesh Gunasekaran; Masato Fujiki; Teresa Diago Uso; Cristiano Quintini; Federico Aucejo; Dympna Kelly; Charles Winans; David P. Vogt; Brian M. Parker; Samuel Irefin; Charles M. Miller; John J. Fung

Ischemic‐type biliary stricture (ITBS) occurs in up to 50% after liver transplantation (LT) from donation after cardiac death (DCD) donors. Thrombus formation in the peribiliary microcirculation is a postulated mechanism. The aim was to describe our experience of tissue plasminogen activator (TPA) administration in DCD‐LT. TPA was injected into the donor hepatic artery on the backtable (n = 22). Two recipients developed ITBS including one graft failure. Although excessive postreperfusion bleeding was seen in 14 recipients, the amount of TPA was comparable between those with and without excessive bleeding (6.4 ± 2.8 vs. 6.6 ± 2.8 mg, p = 0.78). However, donor age (41 ± 12 vs. 29 ± 9 years, p = 0.02), donor BMI (26.3 ± 5.5 vs. 21.7 ± 3.6 kg/m2, p = 0.03), previous laparotomy (50% vs. 0%, p = 0.02) and lactate after portal reperfusion (6.3 ± 4.6 vs. 2.8 ± 0.9 mmol/L, p = 0.005) were significantly greater in recipients with excessive bleeding. In conclusion, the use of TPA may lower the risk of ITBS‐related graft failure in DCD‐LT. Excessive bleeding may be related to poor graft quality and previous laparotomy rather than the amount of TPA. Further studies are needed in larger population.


Transplantation | 2008

Rapamycin, but not cyclosporine or FK506, alters natural killer cell function.

Lu-En Wai; Masato Fujiki; Saori Takeda; Olivia M. Martinez; Sheri M. Krams

Infiltration of natural killer (NK) cells into solid organ allografts is observed in clinical and experimental transplantation. Studies suggest a role for NK cells in acute and chronic rejection of solid organ allografts; however, the effects of immunosuppressive agents on NK cells are not clearly established. Rat NK cell lines were analyzed for proliferation and cytotoxicity in the presence of cyclosporine, FK506, or rapamycin. Lewis recipients of DA liver allografts received immunosuppressive agents after transplantation. NK cells demonstrated robust function both in the absence and presence of cyclosporine and FK506. In contrast, rapamycin significantly inhibited proliferation and cytotoxicity of NK cells. NK cell numbers remained stable in graft recipients treated with cyclosporine and FK506, whereas there was a significant decrease in NK cells in rapamycin-treated recipients. These data indicate that immunosuppressive drugs have differential effects on NK cell function that may impact the immune response of transplant recipients.


Liver Transplantation | 2010

Induced Tolerance to Rat Liver Allografts Involves the Apoptosis of Intragraft T Cells and the Generation of CD4[+]CD25[+]Foxp3[+] T Regulatory Cells

Masato Fujiki; Carlos O. Esquivel; Olivia M. Martinez; Samuel Strober; Shinji Uemoto; Sheri M. Krams

Posttransplant total lymphoid irradiation is a nonmyeloablative regimen that has been extensively studied in rodent models for the induction of tolerance to bone marrow and solid organ allografts. Previous studies of experimental models and clinical transplantation have used total lymphoid irradiation in combination with anti‐lymphocyte–depleting reagents and donor cell infusion to promote graft acceptance. In a rat model of orthotopic liver transplantation, we demonstrated that total lymphoid irradiation alone induced long‐term graft survival. Apoptotic T cells were detected in markedly higher numbers in the livers of the total lymphoid irradiation–treated group in comparison with the control group of liver allograft recipients. Intragraft CD4+CD25+FoxP3+ cells were increased in the total lymphoid irradiation group in the first week post‐transplant and remained elevated in the graft and in the spleen. Importantly, the adoptive transfer of splenocytes from recipients that received posttransplant total lymphoid irradiation prolonged the survival of donor heart grafts, but not third‐party heart grafts, whereas the depletion of CD4+CD25+ cells from transferred splenocytes abrogated this prolongation. We conclude that posttransplant total lymphoid irradiation significantly increases the apoptosis of T cells in the liver graft and allows the accumulation of CD4+CD25+FoxP3+ T regulatory cells, which facilitate the generation of donor‐specific tolerance. Liver Transpl 16:147–154, 2010.


Clinical Transplantation | 2009

Efficacy of tonsillectomy for patients with recurrence of IgA nephropathy after kidney transplantation

Hidetaka Ushigome; T. Suzuki; Masato Fujiki; Syuji Nobori; Seisuke Sakamoto; Masahiko Okamoto; Koji Urasaki; Norio Yoshimura

Abstract:  From January 2007, we started to perform the tonsillectomy for every patient with recurrent IgA nephropathy (IgAN) after kidney transplantation. Up to September 2008, four recipients with primary IgAN had biopsy‐proven recurrent IgAN. They had also progressive hematuria or proteinuria from on the average 14.3 months after transplantation. Then their specimens diagnosed as recurrent IgAN were collected and they underwent tonsillectomies on the average 52.3 months after transplantation. Abnormal urinary findings of all patients favorably improved after tonsillectomy. All cases but one had mild renal injury, where the severity of glomerular lesions, glomerular hypercellularity, segmental lesions, and sclerosis was mild, and no deteriorated serum creatinine (SCr) before their tonsillectomies. Even the case with exacerbated SCr and severe renal injury, where the severity of glomerular lesions was severe, had her urinary findings ameliorated promptly after tonsillectomy likely as others. At present, they have almost no symptoms after tonsillectomy and no remarkable change of SCr level compared with before and after tonsillectomy and maintain ameliorated urinary findings continuously. Tonsillectomy had possibility to be a favorable treatment of hematuria or proteinuria in recurrent IgAN recipients.


Liver International | 2011

General overview of neo-adjuvant therapy for hepatocellular carcinoma before liver transplantation: necessity or option?

Masato Fujiki; Federico Aucejo; Richard Kim

Because of its increasing incidence of hepatocellular carcinoma, it is now recognized as a worldwide health problem affecting mostly patients with chronic liver disease. Liver transplantation is the optimal therapy and achieves its best results in patients with small tumour burden. In an effort to prevent tumour progression and patient dropout from the transplant wait list, the concept and utilization of neo‐adjuvant locoregional therapies have gained relevance in the past few years. Moreover, good and maintained response to therapy is now considered a surrogate of favourable tumour biology, therefore aiding the patient transplant selection process. Herein, we review the current role of neo‐adjuvant therapies and revise concepts of tumour ‘downstaging’ or ‘bridging therapy’ in the setting of liver transplantation. In addition, we explore the debate of implementing locoregional therapy for patients with small tumours and short waiting times to liver transplantation.


Liver Transplantation | 2013

Preparing for the inevitable: The death of a living liver donor: Death of a Living Liver Donor

Charles E. Miller; Martin L. Smith; Masato Fujiki; Teresa Diago Uso; Cristiano Quintini

Living donor liver transplantation (LDLT) is associated with a low but finite and well‐documented risk of donor morbidity and mortality, so organizations and individuals involved in this activity must accept the fact that a donor death is a question of when and not if. Studies in the field of crisis management show that preparing for the inevitable not only is critical in preparing institutions to better respond to catastrophic events but more importantly plays a crucial role in preventing them. This article describes the background of crisis management with specific reference to the death of a living liver donor and proposes a general framework that can be adopted by LDLT programs around the world. Liver Transpl 19:656–660, 2013.


Hpb | 2011

Duct-to-duct biliary reconstruction in patients with primary sclerosing cholangitis undergoing liver transplantation

Jamak Modaresi Esfeh; Bijan Eghtesad; Peter Hodgkinson; Teresa Diago; Masato Fujiki; Koji Hashimoto; Cristiano Quintini; Federico Aucejo; Dympna Kelly; Charles Winans; David P. Vogt; Charles M. Miller; Nizar N. Zein; John J. Fung

BACKGROUND Reconstruction of biliary drainage after liver transplantation (LTx) in patients with primary sclerosing cholangitis (PSC) has been a matter of controversy. Over recent years, the traditional method of Roux-en-Y hepaticojejunostomy (RY) has been challenged by duct-to-duct (DD) biliary reconstruction. METHODS This study represents a retrospective review of biliary complications, patient and graft survival after LTx in PSC patients based on type of biliary reconstruction. Outcomes of DD reconstruction in this group of patients and non-PSC patients are compared. RESULTS A total of 53 primary LTx procedures were performed for PSC between August 2005 and July 2010. Seven patients were excluded because unexpected cholangiocarcinoma was found in the explants (n=3) or because they received partial livers (n=4). Biliary reconstruction was performed as DD in 18 patients and RY in 28 patients. There were no bile leaks. Anastomotic stricture occurred in two (11%) patients in the DD group and one (4%) in the RY group. Two (7%) patients in the RY group developed non-PSC intrahepatic strictures and one had recurrence of PSC. Rates of 1- and 3-year patient and graft survival in the RY and DD groups were 96.7% and 96.7%, and 100% and 94.5%, respectively. In a group of 34 randomly selected patients transplanted for a non-PSC diagnosis with DD reconstruction during the same period, the anastomotic stricture rate was 9% and 1- and 3-year patient and graft survival rates were 97.0% and 88.5%; differences were not significant. CONCLUSIONS Duct-to-duct biliary reconstruction at the time of LTx in selected PSC patients is both effective and safe, and shows outcomes comparable with those of RY reconstruction in these patients and those of DD reconstruction in non-PSC patients.


European Journal of Immunology | 2010

Identification of the rat NKG2D ligands, RAE1L and RRLT, and their role in allograft rejection

Ming Zhuo; Masato Fujiki; Mouer Wang; Karine Piard-Ruster; Lu-En Wai; L. Wei; Olivia M. Martinez; Sheri M. Krams

NKG2D is a receptor expressed by NK cells and subsets of T lymphocytes. On NK cells, NKG2D functions as a stimulatory receptor that induces effector functions. We cloned and expressed two rat NKG2D ligands, both members of the RAE1 family, RAE1L and RRLT, and demonstrate that these ligands can induce IFN‐γ secretion and cytotoxicity by rat NK cells. To examine changes in expression of NKG2D and the NKG2D ligands RAE1L and RRLT after transplantation, we used a Dark Agouti (DA)→Lewis rat model of liver transplantation. NKG2D expression was significantly increased in allogeneic liver grafts by day 7 post‐transplant. Ligands of NKG2D, absent in normal liver, were readily detected in both syngeneic and allogeneic liver grafts by day 1 post‐transplant. By day 7 post‐transplant, hepatocyte RAE1L and RRLT expression was significantly and specifically increased in liver allografts. In contrast to acute rejection that develops in the DA→Lewis model, transplantation of Lewis livers into DA recipients (Lewis→DA) results in spontaneous tolerance. Interestingly, expression of RAE1L and RRLT is low in Lewis→DA liver allografts, but significantly increased in DA→Lewis liver allografts undergoing rejection. In conclusion, our results suggest that expression of NKG2D ligands may be important in allograft rejection.


Annals of Surgery | 2015

Autologous Reconstruction and Visceral Transplantation for Management of Patients With Gut Failure After Bariatric Surgery: 20 Years of Experience.

Kareem Abu-Elmagd; Guilherme Costa; David McMichael; Ajai Khanna; Ruy J. Cruz; Neha Parekh; Masato Fujiki; Koji Hashimoto; Cristiano Quintini; Darlene A. Koritsky; Matthew Kroh; Hiroshi Sogawa; Ahmed Kandeel; José Renan Cunha-Melo; Ezra Steiger; Donald F. Kirby; Laura E. Matarese; Abdullah Shatnawei; Abhinav Humar; R. Matthew Walsh; Philip R. Schauer; Richard L. Simmons; Timothy R. Billiar; John J. Fung

OBJECTIVE Bariatric surgery (BS) is currently the most effective treatment for severe obesity. However, these weight loss procedures may result in the development of gut failure (GF) with the need for total parenteral nutrition (TPN). This retrospective study is the first to address the anatomic and functional spectrum of BS-associated GF with innovative surgical modalities to restore gut function. METHODS Over 2 decades, 1500 adults with GF were referred with history of BS in 142 (9%). Of these, 131 (92%) were evaluated and received multidisciplinary care. GF was due to catastrophic gut loss (Type-I, 42%), technical complications (Type-II, 33%), and dysfunctional syndromes (Type-III, 25%). Primary bariatric procedures were malabsorptive (5%), restrictive (19%), and combined (76%). TPN duration ranged from 2 to 252 months. RESULTS Restorative surgery was performed in 116 (89%) patients with utilization of visceral transplantation as a rescue therapy in 23 (20%). With a total of 317 surgical procedures, 198 (62%) were autologous reconstructions; 88 (44%) foregut, 100 (51%) midgut, and 10 (5%) hindgut. An interposition alimentary conduit was used in 7 (6%) patients. Reversal of BS was indicated in 84 (72%) and intestinal lengthening was required in 10 (9%). Cumulative patient survival was 96% at 1 year, 84% at 5 years, and 72% at 15 years. Nutritional autonomy was restored in 83% of current survivors with persistence or relapse of obesity in 23%. CONCLUSIONS GF is a rare but serious life-threatening complication after BS. Successful outcome is achievable with comprehensive management, including reconstructive surgery and visceral transplantation.


American Journal of Transplantation | 2014

Split liver transplantation using Hemiliver graft in the MELD era: a single center experience in the United States.

Koji Hashimoto; Cristiano Quintini; Federico Aucejo; Masato Fujiki; Teresa Diago; Melissa Watson; Dympna Kelly; Charles Winans; Bijan Eghtesad; John J. Fung; Charles M. Miller

Under the “sickest first” Model for End‐Stage Liver Disease (MELD) allocation, livers amenable to splitting are most often allocated to patients unsuitable for split liver transplantation (SLT). Our experience with SLT using hemilivers was reviewed. From April 2004 to June 2012, we used 25 lobar grafts (10 left lobes and 15 right lobes) for adult‐sized recipients. Twelve recipients were transplanted with primary offers, and 13 were transplanted with leftover grafts. Six grafts were shared with other centers. The data were compared with matched whole liver grafts (n = 121). In 92% of donors, the livers were split in situ. Hemiliver recipients with severe portal hypertension had a greater graft‐to‐recipient weight ratio than those without severe portal hypertension (1.96% vs. 1.40%, p < 0.05). Hemiliver recipients experienced biliary complications more frequently (32.0% vs. 10.7%, p = 0.01); however, the 5‐year graft survival for hemilivers was comparable to whole livers (80.0% vs. 81.5%, p = 0.43). The secondary recipients with leftover grafts did not have increased incidences of graft failure (p = 0.99) or surgical complications (p = 0.43) compared to the primary recipients. In conclusion, while routine application is still controversial due to various challenges, hemiliver SLT can achieve excellent outcomes under the MELD allocation.

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