Dicken S.C. Ko
Harvard University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Dicken S.C. Ko.
The New England Journal of Medicine | 2008
Tatsuo Kawai; A. Benedict Cosimi; Thomas R. Spitzer; Nina Tolkoff-Rubin; Manikkam Suthanthiran; Susan L. Saidman; Juanita Shaffer; Frederic I. Preffer; Ruchuang Ding; Vijay K. Sharma; Jay A. Fishman; Bimalangshu R. Dey; Dicken S.C. Ko; Martin Hertl; Nelson Goes; Waichi Wong; Winfred W. Williams; Robert B. Colvin; Megan Sykes; David H. Sachs
Five patients with end-stage renal disease received combined bone marrow and kidney transplants from HLA single-haplotype mismatched living related donors, with the use of a nonmyeloablative preparative regimen. Transient chimerism and reversible capillary leak syndrome developed in all recipients. Irreversible humoral rejection occurred in one patient. In the other four recipients, it was possible to discontinue all immunosuppressive therapy 9 to 14 months after the transplantation, and renal function has remained stable for 2.0 to 5.3 years since transplantation. The T cells from these four recipients, tested in vitro, showed donor-specific unresponsiveness and in specimens from allograft biopsies, obtained after withdrawal of immunosuppressive therapy, there were high levels of P3 (FOXP3) messenger RNA (mRNA) but not granzyme B mRNA.
Transplantation | 2003
William C. Goggins; Manuel Pascual; John A. Powelson; Colm Magee; Nina Tolkoff-Rubin; Mary Lin Farrell; Dicken S.C. Ko; Winfred W. Williams; Anil Chandraker; Francis L. Delmonico; Hugh Auchincloss; A. Benedict Cosimi
Background. Delayed graft function (DGF) is frequently observed in recipients of cadaveric renal transplants. Previous retrospective or nonrandomized studies have suggested that intraoperative administration of polyclonal antithymocyte preparations may reduce the incidence of DGF, possibly by decreasing ischemia-reperfusion injury. Methods. We performed a prospective randomized study of Thymoglobulin induction therapy in adult cadaveric renal transplant recipients. Between January 2001 and January 2002, 58 adult cadaveric renal transplant recipients were randomized to receive intraoperative or postoperative Thymoglobulin induction therapy. Three to six doses of Thymoglobulin (1 mg/kg/dose) were administered during the first week posttransplant. Baseline immunosuppression consisted of tacrolimus (54 of 58) or cyclosporine A (4 of 58), steroids, and mycophenolate mofetil. DGF was defined by the requirement for hemodialysis within the first week posttransplant. Results. There were no significant differences between the two groups in recipient demographics, donor age, cold ischemia time, or total number of doses of Thymoglobulin administered. Intraoperative Thymoglobulin administration was associated with significantly less DGF and a lower mean serum creatinine on postoperative days 10 and 14 (P <0.05). Posttransplant length of stay was also significantly shorter for the intraoperative Thymoglobulin patient group. The acute rejection rate was also lower in the intraoperative treatment group but this did not achieve statistical significance. There was no difference in the incidence of cytomegalovirus disease between the two groups. Conclusions. The results of this study indicate that intraoperative Thymoglobulin administration, in adult cadaveric renal transplant recipients, is associated with a significant decrease in DGF, better early allograft function in the first month posttransplant, and a decreased posttransplant hospital length of stay.
Transplantation | 1999
Tatsuo Kawai; Alain Poncelet; David H. Sachs; Shamila Mauiyyedi; Svetlan Boskovic; Siew Lin Wee; Dicken S.C. Ko; Amelia Bartholomew; Masaaki Kimikawa; Han Zhou Hong; Gregory Avedis Abrahamian; Robert B. Colvin; A. Benedict Cosimi
BACKGROUND Multilineage chimerism and long-term acceptance of renal allografts has been produced in non-human primates conditioned with a nonmyeloablative regimen. Our study was undertaken to evaluate the immunological and pathological status of long-term survivors and to define the role of splenectomy and of the primarily vascularized kidney in the regimen. METHOD Monkeys were treated with the basic regimen, including: total body irradiation, thymic irradiation, antithymocyte globulin, donor bone marrow transplantation, and a 4-week course of cyclosporine after which no further immunosuppression was given. They were divided into four groups according to the timing of kidney transplantation (KTx) and splenectomy as follows; group A (n=13): KTx and splenectomy on the day of donor bone marrow transplantation (day 0); group B (n=3): KTx on day 0 without splenectomy; group C (n=7): splenectomy on day 0 but delayed KTx until 3 to 16 weeks post-donor bone marrow transplantation; group D (n=3): both splenectomy and KTx delayed until day 120 post-donor bone marrow transplantation. RESULTS In group A, 11 of 13 monkeys developed chimerism and 9 monkeys achieved long-term survival of 4 to 70 months without evidence of chronic vascular rejection. Alloantibodies were detected in only one long-term survivor. In contrast, all three monkeys in group B developed alloantibodies and rejected their allografts. In group C, long-term survival without alloantibody production was observed in two of three monkeys that had developed chimerism. In group D, all three recipients were sensitized and rejected the kidney allografts rapidly after transplantation. CONCLUSIONS 1) Production of anti-donor antibody was prevented in most recipients that developed mixed chimerism in the regimens with splenectomy at the time of donor bone marrow transplantation. 2) If splenectomy is not included in the initial conditioning regimen, induction of B cell tolerance is less likely and the result is late onset of alloantibody production and allograft rejection. 3) Immediate transplantation of the kidney at the time of recipient conditioning is not essential for induction of donor specific hyporesponsiveness by bone marrow transplantation.
American Journal of Transplantation | 2007
R. Saidi; Nahel Elias; Tatsuo Kawai; Martin Hertl; Farrell Ml; Nelson Goes; Waichi Wong; C. Hartono; Jay A. Fishman; Camille N. Kotton; Nina Tolkoff-Rubin; Francis L. Delmonico; Cosimi Ab; Dicken S.C. Ko
Expanded criteria donors (ECDs) and donation after cardiac death (DCD) provide more kidneys in the donor pool. However, the financial impact and the long‐term benefits of these kidneys have been questioned. From 1998 to 2005, we performed 271 deceased donor kidney transplants into adult recipients. There were 163 (60.1%) SCDs, 44 (16.2%) ECDs, 53 (19.6%) DCDs and 11 (4.1%) ECD/DCDs. The mean follow‐up was 50 months. ECD and DCD kidneys had a significantly higher incidence of delayed graft function, longer time to reach serum creatinine below 3 (mg/dL), longer length of stay and more readmissions compared to SCDs. The hospital charge was also higher for ECD, ECD/DCD and DCD kidneys compared to SCDs, primarily due to the longer length of stay and increased requirement for dialysis (
Transplantation | 2008
Karen J. Ho; Christopher D. Owens; Scott R. Johnson; Khalid Khwaja; Michael P. Curry; Martha Pavlakis; Didier A. Mandelbrot; James J. Pomposelli; Shimul A. Shah; Reza F. Saidi; Dicken S.C. Ko; Sayeed K. Malek; John Belcher; David Hull; Stefan G. Tullius; Richard B. Freeman; Elizabeth A. Pomfret; James F. Whiting; Douglas W. Hanto; Seth J. Karp
70 030,
The Journal of Urology | 1995
Dicken S.C. Ko; Howard N. Fenster; Keith Chambers; Lorne D. Sullivan; Martha Jens; Larry Goldenberg
72 438,
American Journal of Transplantation | 2010
R. Saidi; James Bradley; D. Greer; Richard S. Luskin; K. O’Connor; Francis L. Delmonico; Peter T. Kennealey; F. Pathan; Christian Schuetz; Nahel Elias; Dicken S.C. Ko; Tatsuo Kawai; Martin Hertl; Cosimi Ab; James F. Markmann
72 789 and
Transplantation | 1998
Pascual M; H. Vallhonrat; Cosimi Ab; Nina Tolkoff-Rubin; Robert B. Colvin; Francis L. Delmonico; Dicken S.C. Ko; David A. Schoenfeld; Winfred W. Williams
47 462, respectively, p < 0.001). Early graft survival rates were comparable among all groups. However, after a mean follow‐up of 50 months, graft survival was significantly less in the ECD group compared to other groups. Although our observations support the utilization of ECD and DCD kidneys, these transplants are associated with increased costs and resource utilization. Revised reimbursement guidelines will be required for centers that utilize these organs.
Archives of Surgery | 2009
Reza F. Saidi; Tatsuo Kawai; Peter T. Kennealey; Georgios Tsouflas; Nahel Elias; Martin Hertl; Cosimi Ab; Dicken S.C. Ko
Background. Compared with standard donors, kidneys recovered from donors after cardiac death (DCD) exhibit higher rates of delayed graft function (DGF), and DCD livers demonstrate higher rates of biliary ischemia, graft loss, and worse patient survival. Current practice limits the use of these organs based on time from donor extubation to asystole, but data to support this is incomplete. We hypothesized that donor postextubation parameters, including duration and severity of hemodynamic instability or hypoxia might be a better predictor of subsequent graft function. Methods. We performed a retrospective examination of the New England Organ Bank DCD database, concentrating on donor factors including vital signs after withdrawal of support. Results. Prolonged, severe hypotension in the postextubation period was a better predictor of subsequent organ function that time from extubation to asystole. For DCD kidneys, this manifested as a trend toward increased DGF. For DCD livers, this manifested as increased rates of poor outcomes. Maximizing the predictive value of this test in the liver cohort suggested that greater than 15 min between the time when the donor systolic blood pressure drops below 50 mm Hg and flush correlates with increased rates of diffuse biliary ischemia, graft loss, or death. Donor age also correlated with worse outcome. Conclusions. Time between profound instability and cold perfusion is a better predictor of outcome than time from extubation to asystole. If validated, this information could be used to predict DGF after DCD renal transplant and improve outcomes after DCD liver transplant.
Transplantation | 1999
Tatsuo Kawai; Siew Lin Wee; Hervé Bazin; Dominique Latinne; Joanne Phelan; Svetlan Boskovic; Dicken S.C. Ko; Han Zhou Hong; Shamila Mauiyyedi; O. Nadazdin; Gregory Avedis Abrahamian; Frederic I. Preffer; Robert B. Colvin; David H. Sachs; A. Benedict Cosimi
PURPOSE We correlated multichannel pressure-flow urodynamics and the American Urological Association (AUA) symptom index in the evaluation of benign prostatic hyperplasia. MATERIALS AND METHODS We evaluated 121 consecutive, symptomatic patients older than 55 years with the AUA symptom score and multichannel pressure-flow urodynamic studies. Testing was performed during a single session and the data obtained from 103 patients were plotted on the Schäfer nomogram for assessment of outflow obstruction. Linear regression statistical analysis was used to determine correlations. RESULTS There was no significant correlation between uroflowmetry and Schäfer curves (r = 0.173 to 0.326), uroflowmetry and AUA symptom scores (r = 0.134 to 0.153) and, most importantly, AUA symptom scores and Schäfer curves (r = 0.025 to 0.137). CONCLUSIONS We conclude that these modalities measure independent variables, and should not be linked in the evaluation and treatment decision of the patient with prostatism.