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R W Busuttil

Publications and source records attributed to R W Busuttil.

At least 19 recordsLinked to original sources
PubMed2006

FK330, a novel inducible nitric oxide synthase inhibitor, prevents ischemia and reperfusion injury in rat liver transplantation.

Nitric oxide (NO), produced via inducible NO synthase (iNOS), is implicated in the pathophysiology of liver ischemia/reperfusion injury (IRI). We examined the effects of a novel iNOS inhibitor, FK330 (FR260330), in well-defined rat liver IRI models. In a model of liver cold ischemia followed by ex vivo reperfusion, treatment with FK330 improved portal venous flow, increased bile production and decreased hepatocellular damage. FK330 prevented IRI in rat model of 40-h cold ischemia followed by syngeneic orthotopic liver transplantation (OLT), as evidenced by: (1) increased OLT survival (from 20% to 80%); (2) decreased hepatocellular damage (serum glutamic oxaloacetic transaminase/glutamic pyruvic transaminase levels); (3) improved histological features of IRI; (4) reduced intrahepatic leukocyte infiltration, as evidenced by decreased expression of P-selectin/intracellular adhesion molecule 1, ED-1/CD3 cells and neutrophils; (5) depressed lymphocyte activation, as evidenced by expression of pro-inflammatory cytokine (TNF-alpha, IL-1beta, IL-6) and chemokine (IP-10, MCP-1, MIP-2) programs; (6) prevented hepatic apoptosis and down-regulated Bax/Bcl-2 ratio. Thus, by modulating leukocyte trafficking and cell activation patterns, treatment of rats with FK330, a specific iNOS inhibitor, prevented liver IRI. These results provide the rationale for novel therapeutic approaches to maximize organ donor pool through the safer use of liver grafts despite prolonged periods of cold ischemia.

Animals↗
PubMed2006

Split liver transplantation.

Seventy-five thousand Americans develop organ failure each year. Fifteen percent of those on the list for transplantation die while waiting. Several possible mechanisms to expand the organ pool are being pursued including the use of extended criteria donors, living donation, and split deceased donor transplants. Cadaveric organ splitting results from improved understanding of the surgical anatomy of the liver derived from Couinaud. Early efforts focused on reduced-liver transplantation (RLT) reported by both Bismuth and Broelsch in the mid-1980s. These techniques were soon modified to create both a left lateral segment graft appropriate for a pediatric recipient and a right trisegment for an appropriately sized adult. Techniques of split liver transplantation (SLT) were also modified to create living donor liver transplantation. Pichlmayr and Bismuth reported successful split liver transplantation in 1989 and Emond reported a larger series of nine split procedures in 1990. Broelsch and Busuttil described a technical modification in which the split was performed in situ at the donor institution with surgical division completed in the heart beating cadaveric donor. In situ splitting reduces cold ischemia, simplifies identification of biliary and vascular structures, and reduces reperfusion hemorrhage. However, in situ splits require specialized skills, prolonged operating room time, and increased logistical coordination at the donor institution. At UCLA over 120 in situ splits have been performed and this technique is the default when an optimal donor is available. Split liver transplantation now accounts for 10% of adult transplantations at UCLA and 40% of pediatric transplantations.

Adult↗
PubMed2006

Prevalence and risk factors for diabetes mellitus in moderate term survivors of liver transplantation.

The prevalence and risk factors for diabetes mellitus after liver transplantation are not well understood. Thus, we sought to identify independent risk factors for the development of diabetes after liver transplantation using currently accepted medical criteria. We studied the prevalence and risk factors in 253 adult recipients transplanted at UCLA between January 1998 and December 2002. Analysis of the retrospective data was performed using demographic, immunosuppression and liver disease variables. Factors found to be significant on a univariate analysis were further studied in a multivariate analysis. There were 158 men and 95 women in our study. The mean age was 51.4 +/- 11.0 years. The mean [+/- standard deviation (SD) pretransplant body mass index was 26.7 (+/-5.1). Most patients were transplanted for hepatitis C (HCV). The prevalence of diabetes after transplantation was 17.8%. In a multivariate analysis only gender [odds ratio (OR) = 0.37; p = 0.02] was independently predictive of the development of diabetes. This study in a large liver transplant recipient population identifies male gender as an independent risk factor for the development of diabetes. Follow-up studies are needed to assess the impact of diabetes, and its intervention on post-transplant morbidity and mortality.

Diabetes Mellitus↗
PubMed2005

Donor MHC class I peptides in conjunction with self-epitopes induce donor-specific tolerance in a dose-dependent manner but unable to abrogate chronic rejection.

Understanding specific tolerance mechanisms is a primary goal of transplantation science. We have previously shown that hosts treated with MHC class I protein have donor sequences in the alpha1-helix of the alpha1 domain on a background of self-epitopes, resulting in the development of donor-specific tolerance. However, the nature of class I alloantigenic determinants that regulate the alloimmune response remains unclear. The alpha1-helical sequence of RT1.A,1 which shares RT1.A(u) sequences, was substituted in the RT1.A(a) molecule to produce the composite [alpha1h(l/u)]-RT1.A(a) MHC class I allochimeric molecule. Immunodominant epitopes were identified within the hypervariable region of the alpha1 domain of RT1.A(a) (ACI), RT1.Al (Lewis, LEW), and RT1.A(u) (Wistar Furth [WF]). To clarify the mechanisms of tolerance development through presentation of donor-type immunogenic epitopes and cryptic self-epitopes we used synthetic peptides corresponding to donor immunogenic determinants with peptides derived from recipient self-sequences (RT1.A(a)--aa 10 to 49 P1 and 91 to 120 P3; and P2 RT1.A(l/u) 50 to 90). ACI recipients of LEW and WF cardiac allografts were injected through the portal vein (PV) at day 0 with four doses (2, 0.5, 0.25, and 0.125 mg/rat) of three peptide mixtures in conjunction with subtherapeutic CsA (10 mg/kg for 3 days). Allograft survival was strongly dose-dependent. Only low-dose regimens were consistent in tolerance induction, but such therapy did not abrogate development of chronic rejection (CR), unlike allochimeric therapy with soluble MHC class I protein. Different effects of protein or synthetic peptide therapies on development of CR suggest that development of specific tolerance is an active immunologic process and it depends on the form of allogeneic epitopes presented.

Animals↗
PubMed2005

HO-1 upregulation suppresses type 1 IFN pathway in hepatic ischemia/reperfusion injury.

Upregulation of heme oxygenase (HO)-1, a heat shock protein 32, protects against hepatic ischemia/reperfusion (I/R) injury. Activation of "innate" toll-like receptor (TLR) 4 system triggers the I/R injury cascade. This study explores cytoprotective functions of HO-1 overexpression following exogenous administration of cobalt protoporphyrin (CoPP), and its relationship with the TLR4 pathway in a model of mouse partial hepatic warm I/R injury. CoPP treatment markedly improved hepatic function and histology, and suppressed pro-inflammatory cytokine elaboration profile, as compared with untreated controls. Although administration of CoPP did not affect intrahepatic TLR4, it downregulated IFN-inducible protein 10 (IP-10) expression. As IP-10 is the major product of type-1 IFN pathway downstream of TLR4, we then infused recombinant IFN-beta (rIFN-beta) directly into mouse livers. Interestingly, infusion of rIFN-beta upregulated hepatic IP-10 expression. In contrast, adjunctive CoPP treatment decreased IP-10 levels in mouse livers infused with rIFN-beta. Thus, CoPP-induced HO-1 upregulation suppresses type-1 IFN pathway downstream of TLR4 system in hepatic warm I/R injury model.

Animals↗
PubMed2005

Ischemia and reperfusion injury in liver transplantation.

Ischemia/reperfusion (I/R) injury is a multifactorial process detrimental to liver graft function. An understanding of the mechanisms involved in I/R injury is essential for the design of therapeutic strategies to improve the outcome of liver transplantation. The generation of reactive oxygen species subsequent to reoxygenation inflicts tissue damage and initiates a cellular cascade leading to inflammation, cell death, and ultimate organ failure. The accruing evidence suggests that Kupffer cells and T cells mediate the activation of neutrophil inflammatory responses. Activated neutrophils infiltrate the injured liver in parallel with increased expression of adhesion molecules on endothelial cells. The heme oxygenase (HO) system is among the most critical of the cytoprotective mechanisms activated during the cellular stress, exerting anti-oxidant and anti-inflammatory functions, modulating the cell cycle, and maintaining the microcirculation. The activation of toll-like receptors (TLR) on Kupffer cells may provide the triggering signal for pro-inflammatory responses in the I/R injury sequence. Indeed, dissecting TLR downstream signaling pathways plays a fundamental role in exploring novel therapeutic strategies based on the concept that hepatic I/R injury represents a case for host "innate" immunity.

Humans↗
PubMed2005

Identification of early tolerance regulator genes induced by allochimeric therapy using microarray-based genomewide scan.

We have demonstrated that peri- or postoperative delivery of allochimeric [a1h(u)]-RT1.A(a) class I major histocompatibility complex molecules with donor-type (RT1A(u)) immunogenic epitopes presented in recipient-type (RT1A(a)) sequences induced donor-specific tolerance in ACI (RT1a) recipients of WF (RT1u) heart allografts. A genomic scan during the early posttransplant period was performed to elucidate the underlying operative mechanisms. A rat genome study after transplantation was carefully designed using Affymetrix Rat Genome 230 2.0 Array. The allochimeric treatment group is 3-day cyclosporine (CsA)-treated ACI recipients that accepted Wistar Furth RT1u cardiac allografts with postoperative dosage of allochimeric molecules, while the control is 3-day CsA-treated ACI recipients of WF cardiac allografts. All the samples were harvested 5 days after heart transplant as the early stage of tolerance detection. Following array data normalization and modeling, we compared the above two treatment groups and identified a total of 250 tolerance regulator genes induced by allochimeric molecules only.

Animals↗
PubMed2005

Cyclic RGD peptides with high affinity for alpha5beta1 integrin protect genetically fat Zucker rat livers from cold ischemia/reperfusion injury.

We tested a hypothesis that interactions between fibronectin (FN), a key extracellular matrix component, and its integrin alpha5beta1 receptor are important in the development of ischemia/reperfusion (I/R) injury of steatotic liver transplants. We examined the effect of a cyclic RGD peptide (cRGD), with high affinity for alpha5beta1 integrin, in a well-established steatotic rat liver model of ex vivo cold ischemia followed by isotransplantation. In this model, cRGD peptides were administered through the portal vein of steatotic Zucker rat livers prior to and after cold ischemic storage. Lean Zucker recipients of fatty orthotopic liver transplants (OLTs) received an additional course of cRGD peptides 1 hour posttransplantation. cRGD peptide therapy significantly inhibited the recruitment of monocyte/macrophages, and repressed the expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. Moreover, it resulted in selective inhibition of inducible nitric oxide synthase (iNOS), and MMP-9 expression. Importantly, cRGD peptide therapy improved the function and histologic preservation of steatotic liver grafts, extending their 14-day survival in lean recipients from 50% in untreated to 100% in cRGD-treated OLTs. Thus, cRGD peptide-mediated blockade of FN-alpha5beta1 interaction protects against severe I/R injury otherwise experienced by steatotic OLTs.

Animals↗
PubMed2004

P-selectin knockout mice have improved outcomes with both warm ischemia and small bowel transplantation.

AIM: To analyze the role of P-selectin in intestinal ischemia and reperfusion injury (IRI) using murine models. METHODS: A model of warm IRI wherein the SMA was occluded for 100 minutes was undertaken in the following groups (10 mice per group): Group 1 (control) wild-type (WT) C57BL6, no treatment; Group 2: 0.4 mg/kg of r-PSGL1-lg 10 minutes before and after clamping; Group 3: PSGL KO mice. Survival was assessed at 7 days; the intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), IL1, and TNF. A second model of cold IRI followed by intestinal transplantation (IT) was undertaken in the following groups (two mice per group): Group A WT --> WT: Group B PSGL KO --> WT (1-hour ischemia); Group C: PSGL KO --> WT (2 hour ischemia). Survival only was assessed. RESULTS: Survival was 50% in group 1, 90% in group 2, and 100% in group 3. Graded histopathology and crypt apoptosis demonstrated significantly less injury in groups B and C. MPO was not different between groups. IL1 and TNF were significantly reduce in groups 2 and 3. Following IT, survival was <12 hours in group A, >7 days in group B, and <72 hours in group C. CONCLUSION: This study clearly demonstrates the importance of P-selectin in warm and cold IRI in that the blockade of P-selectin using rPSGL1-lg or the absence of P-selectin using KO mice confers a survival advantage and reduction in tissue injury. The mechanism is unclear but appears to be independent of neutrophil infiltration.

Animals↗
PubMed2004

Application of combined liver-intestinal transplantation as a staged procedure.

Liver-intestinal transplantation is a complex surgical procedure that historically has required prolonged operative periods. This report is the first series where liver-intestinal transplantation was performed as a staged procedure. Specifically, allograft reperfusion was followed by resuscitation and stabilization in an intensive care unit before completion of the transplant procedure. Triage of recipients to the intensive care unit following allograft reperfusion was determined at the time of operation and was based upon the clinical condition of the recipient including hemodynamic stability, evidence of coagulopathy, and assessment of early liver function. Medical stabilization was followed by completion of the transplant procedure and definitive abdominal closure within 72 hours. The application of combined liver-intestinal transplantation as a staged procedure demonstrated no effect upon early graft function, incidence of complications, or ability to perform a definitive abdominal closure.

Adult↗
PubMed2004

Infectious enteritis after intestinal transplantation: incidence, timing, and outcome.

AIM: To review the incidence, timing, and outcome of infectious enteritis after intestinal transplantation (IT). METHOD: A retrospective review of all patients undergoing IT at a single institution between 1991 and 2003 was analyze with standard statistical tools. RESULTS: Among 33 IT recipients, 13 (39%) developed 20 culture- or biopsy-proven episodes of infectious enteritis. The recipient demographics were 77% men and median age 2.6 years. Infections were diagnosed at a median of 76 days (32 to 1800) after IT. There were 14 viral (CMV one, rotavirus eight, adenovirus four, EBV one, three bacterial (Clostridium difficile), and three other infections (Giardia lamblia one, cryptosporidium two). Complete resolution was achieved in 17 (94%) infectious after appropriate antimicrobial or conservative therapy. Interestingly, there were six rejection episodes following infectious enteritis. Grafts were lost to rejection after rotaviral enteritis (n = 1) and adenoviral enteritis misdiagnosed as rejection (n = 1). Patient and graft survival were not adversely affected by infections. CONCLUSIONS: Infectious enteritis occurs frequently after IT. Viral agents are the cause in two-thirds of cases. With supportive care and appropriate treatment, resolution is possible in the majority of cases. Differentiating rejection and infection by histopathology can be difficult.

Adult↗
PubMed2004

Improved outcome after intestinal transplantation at a single institution over 12 years.

PURPOSE: To evaluate the outcomes of patients undergoing intestinal transplantation (IT). METHODS: Retrospective review was undertaken using existing medical records and database. RESULTS: Between November 1991 and May 2003, 114 patients were referred for consideration for IT, of which 33 patients received 37 intestinal allografts. All patients had intestinal failure and all patients had significant complications from total parenteral nutrition (TPN). TPN was the predominant cause of liver failure (63%). Combined liver intestinal grafts were used in the majority of patients. Overall 1- and 3-year patient survival is 77% and 52% with patients transplanted since 1999 having a 1- and 3-year survival of 94% and 73%, respectively. The most common cause of death was sepsis. No graft or patient was lost to cytomegalovirus or Epstein-Barr virus disease. Twenty-seven percent of allografts were lost to rejection. Long-term TPN independence is 82% for grafts more than 30 days after IT. Statistical analysis revealed several important factors impacting outcome. CONCLUSIONS: Successful IT defined as prolonged patient and graft survival and TPN independence can be readily achieved in select patients with IF and complications related to TPN therapy. Outcomes have improved with experience gained and control of viral infections and rejection.

Adolescent↗
PubMed2004

Induction therapy with interleukin-2 receptor antagonist after intestinal transplantation is associated with reduced acute cellular rejection and improved renal function.

PURPOSE: To determine the effectiveness of induction immunotherapy with interleukin-2 receptor antagonists (IL2RA) after intestinal transplantation (IT). METHODS: A single-center, retrospective study was undertaken of all patients undergoing IT using existing medical records and database. Immunotherapy was either triple (standard maintenance triple therapy [SMTT]) or IL2RA [induction IL2RA plus SMTTx] or OKT3 [induction antilymphocyte preparations plus SMTTx]). Data was collected for the first 175 postoperative days. Outcomes included pretransplant renal function, posttransplant serum creatinine normalized to age (nl-sCR), rejection (ACR), and survival. Standard statistical analysis was undertaken. RESULTS: There were no significant differences in the groups: triple (n = 10, median age 3.5 years, cGFR 106 +/- 44 mL/min), IL2RA (n = 13, median age 3.2 years, cGFR 101 +/- 61 mL/min), OKT3 (n = 4, median age 7.7 years, cGFR 104 +/- 27 mL/min). nl-sCR was significantly (P <.01) lower in IL2RA at most postoperative weeks. IL2RA had significantly fewer rejection and infectious episodes than the other two groups. Three-year patient survival was 92% in IL2RA versus 50% triple and OKT3. CONCLUSIONS: IL2RA immunotherapy after IT is associated with a lower incidence of renal dysfunction as compared with historical controls. Furthermore, IL2RA therapy resulted in a lower incidence of rejection and improved survival. IL2RA should be considered in select patients undergoing IT.

Child↗
PubMed2003

Heavy chain ferritin acts as an antiapoptotic gene that protects livers from ischemia reperfusion injury.

Heme oxygenase-1 (HO-1) is induced under a variety of pro-oxidant conditions such as those associated with ischemia-reperfusion injury (IRI) of transplanted organs. HO-1 cleaves the heme porphyrin ring releasing Fe2+, which induces the expression of the Fe2+ sequestering protein ferritin. By limiting the ability of Fe2+ to participate in the generation of free radicals through the Fenton reaction, ferritin acts as an anti-oxidant. We have previously shown that HO-1 protects transplanted organs from IRI. We have linked this protective effect with the anti-apoptotic action of HO-1. Whether the iron-binding properties of ferritin contributed to the protective effect of HO-1 was not clear. We now report that recombinant adenovirus mediated overexpression of the ferritin heavy chain (H-ferritin) gene protects rat livers from IRI and prevents hepatocellular damage upon transplantation into syngeneic recipients. The protective effect of H-ferritin is associated with the inhibition of endothelial cell and hepatocyte apoptosis in vivo. H-ferritin protects cultured endothelial cells from apoptosis induced by a variety of stimuli. These findings unveil the anti-apoptotic function of H-ferritin and suggest that H-ferritin can be used in a therapeutic manner to prevent liver IRI and thus maximize the organ donor pool used for transplantation.

Adenoviridae↗
PubMed2003

Biliary complications after adult living donor liver transplantation.

We evaluated the causes and outcomes of biliary complications occurring after adult living donor liver transplantation (ALDLT) in a large patient cohort. Among 46 patients who underwent ALDLT at two different centers early bile duct complications occurred in 11 recipients (23.9%), consisting of leakage from the anastomotic site or from the cut surface of the liver. T-tube-associated biliary complications occurred in four patients. Late complications, primarily anastomotic strictures, occurred in 15 patients (32.6%) at 6.7+/-3.5 months after transplantation. Surgical intervention was generally required for early biliary complications but rarely necessary for late complications. No graft loss was caused by biliary complications. Thus, ALDLT is accompanied by a high rate of biliary complications, which in our series have been of low severity. However, long-term effects on graft function are not yet known.

Adult↗
PubMed2003

Biliverdin protects rat livers from ischemia/reperfusion injury.

OBJECTIVE: To explore putative cytoprotective functions of biliverdin during hepatic ischemia/reperfusion (I/R) injury in rat models. MATERIAL AND METHODS: Male Sprague Dawley (SD) rat livers were harvested and stored for 24 hours at 4 degrees C in University of Wisconsin (UW) solution (n=18), and then perfused with blood for 2 hours on an isolated rat liver perfusion apparatus equipped for temperature (37 degrees C), pressure (13 cm H2O), and pH (7.3) maintenance. Biliverdin was added to the blood at concentrations of 10 and 50 micromol in two groups of six animals. Portal vein blood flow, bile production, and GOT/GPT levels were assessed serially. At the conclusion of the experiment, liver samples were collected for histologic evaluation using Suzuki criteria. RESULTS: BV exerted protective effects against liver I/R injury. Adjunctive biliverdin improved portal venous blood flow (mL/min/g) from the beginning of reperfusion (1.33+/-0.17 versus 0.98+/-0.15; P<.001) and increased bile production (mL/g) as compared with the control group (3.40 versus 1.88; P<.003). I/R-induced hepatocellular damage as measured by GOT/GPT release (IU/L) was diminished in the biliverdin group (91 versus 171 and 46 versus 144, respectively; P<.0001). Improved liver function by biliverdin was accompanied by preservation of the histologic structure as assessed by Suzuki criteria (3.7+/-1.4 versus 6.8+/-0.8 in untreated controls; P<.005). CONCLUSIONS: Biliverdin attenuates the ischemia/early reperfusion injury of rat liver grafts as assessed by hemodynamics, function, enzyme analysis, and histology. This study provides the rationale for novel therapeutic approaches using biliverdin to maximize the organ donor pool through the safer use of liver transplants despite prolonged periods of cold ischemia.

Alanine Transaminase↗
PubMed2003

Practical management of liver transplant recipients for hepatitis C.

Hepatitis C is one of the leading indications for liver transplantation. Recipients can expect at least a short-term survival equivalent to other indications for liver transplantation. However, the rates of cirrhosis and decompensation development is substantially faster than those rates seen in non-transplant setting. Advances in antiviral therapy are now associated with a sustained virological response of 20% with combination antiviral with interferon and ribavirin. Higher response rates are expected with utilizing pegylated interferon.

Antiviral Agents↗