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Ronald W Busuttil

Publications and source records attributed to Ronald W Busuttil.

At least 73 records · Page 4Linked to original sources
PubMed2004

Laparoscopic bile duct injuries: management at a tertiary liver center.

Bile duct injury is a rare but morbid complication of laparoscopic cholecystectomy (LC). This study was undertaken to evaluate the management of 20 patients with bile duct injuries during LC who were referred to a tertiary center with expertise in hepatobiliary surgery and liver transplantation. Sixteen (80%) were female. Mean age was 44 (range 13-70) years. Half of the injuries were distal (Bismuth I), and nearly half were diagnosed at LC. Reoperative repair was attempted in 30 per cent. Mean interval between injury and operation was 6.55 months (range 0 to 36 months). Eighteen patients underwent Roux-en-Y hepaticojejunostomy (HJ). Of the two patients who did not undergo HJ (both Bismuth I), one was treated with transhepatic cholangiography only, and one died of multiorgan failure. There were four minor complications and one late reoperation for stricture. We conclude that bile duct injury after LC is successfully managed in a tertiary center by a hepatobiliary-liver transplant team. Principles of management include anatomic definition of injury, control of sepsis, staged approach involving interventional radiology, and operative techniques refined in liver transplantation including magnification, fine sutures, selective use of internal stent, and liver biopsy.

Adolescent↗
PubMed2003

Systemic rather than local heme oxygenase-1 overexpression improves cardiac allograft outcomes in a new transgenic mouse.

Heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme catabolism, exhibits potent antioxidant and anti-inflammatory properties. We developed HO-1 transgenic (Tg) mice using a rat HO-1 genomic transgene under the control of the endogenous promoter. Transgene expression was demonstrated by RT-PCR in all studied tissues, and a modest HO-1 overexpression was documented by Western, ELISA, and enzyme activity assays. To assess the effect of local vs systemic HO-1 in the acute rejection response, we used Tg mice as organ donors or recipients of MHC-incompatible heart grafts. In the local HO-1 overexpression model, Tg allografts survived 10.5 +/- 0.7 days (n = 10), compared with 6.5 +/- 0.4 days (n = 6) for wild-type donor controls (p = 0.0001). In the systemic HO-1 overexpression model, Tg recipients maintained allografts for 26.8 +/- 3.4 days (n = 10), compared with 6.3 +/- 0.1 days (n = 12) in wild-type controls (p = 0.00009). Inhibition of HO activity by treatment with tin protoporphyrin blunted survival advantage in Tg mice and resulted in acute graft rejection (n = 3). Increased carboxyhemoglobin levels were consistently noted in Tg mice. Comparisons of grafts at day 4 indicated that HO-1 overexpression was inversely associated with vasculitis/inflammatory cell infiltrate in both models. Hearts transplanted into Tg recipients showed decreased CD4(+) lymphocyte infiltration and diminished immune activation, as judged by CD25 expression. Thus, although local and systemic HO-1 overexpression improved allograft outcomes, systemic HO-1 led to a more robust protection and resulted in a significant blunting of host immune activation. This Tg mouse provides a valuable tool to study mechanisms by which HO-1 exerts beneficial effects in organ transplantation.

Animals↗
PubMed2003

Phosphorus ans an early predictive factor in patients with acute liver failure.

BACKGROUND: This study analyzes the prognostic significance of serum phosphorus in patients with acute liver failure (ALF). METHODS: We performed a retrospective analysis of 112 patients with ALF. Univariate and bivariate analyses based on Kaplan-Meier recovery curves and a multivariate Classification Tree Structure Survival Analysis were performed to identify independent predictors of outcome. The variables analyzed were age, gender, race, ABO blood group, etiology of liver disease, grade of encephalopathy, serum bilirubin, prothrombin time, creatinine, serum phosphorus, phosphorus administered, phosphorus binders, and hemodialysis. RESULTS: The median follow-up time was 5 days, the median age was 28 years, and 62% of the patients were female. The patients' outcomes were as follows: 28% recovered, 52% required orthotopic liver transplantation, and 20% died. White patients showed the best prognosis (58% recovered in the first week), and Hispanics showed the worst prognosis (0.3% recovered at 1 week) (P=0.0001). Encephalopathy and bilirubin were significant predictors of recovery (P<0.0001 and P=0.004). The analysis of the serum phosphorus showed a statistically significant better prognosis in patients with low phosphorus (P<0.001). The recovery rate at 1 week was 74% in patients with serum phosphorus less than 2.5 mg/dL, 45% if phosphorus ranged between 2.5 to 5 mg/dL, and 0% if phosphorus was more than 5 mg/dL. The bivariate analysis on the effects of phosphorus administration showed that phosphorus replacement was associated with a significant improvement in recovery in patients with low (P<0.004) or normal serum phosphorus levels (P<0.017) CONCLUSIONS: Hypophosphatemia and early phosphorus administration are associated with a good prognosis in ALF, whereas hyperphosphatemia is predictive of poor recovery.

Adult↗
PubMed2003

Interleukin-13 gene transfer protects rat livers from antigen-independent injury induced by ischemia and reperfusion.

BACKGROUND: Ischemia-reperfusion (I/R) injury is a prime inflammatory factor in the dysfunction of orthotopic liver transplants. Interleukin (IL)-13 suppresses macrophage production of proinflammatory mediators. This study explores the effects of adenovirus (Ad)-based IL-13 gene transfer in rat models of hepatic I/R injury. METHODS: The authors used a model of warm in situ ischemia followed by reperfusion, and ex vivo cold ischemia followed by transplantation. RESULTS: In a model of warm in situ ischemia followed by reperfusion, Ad-based IL-13 significantly diminished hepatocellular injury, assessed by serum glutamic oxaloacetic transaminase (SGOT) levels, as compared with Ad-based beta-galactosidase (gal)-treated livers. In a model of ex vivo cold ischemia followed by transplantation, the survival of liver grafts increased from 50% in Ad-beta-gal untreated controls to 100% after Ad-IL-13 gene therapy. This beneficial effect correlated with improved liver function (SGOT levels), preservation of hepatic histologic integrity and architecture (Suzuki criteria), and depression of neutrophil infiltration (myeloperoxidase assay). Ad-IL-13 diminished activation of macrophage-neutrophil-associated tumor necrosis factor-alpha, macrophage inflammatory protein-2, and endothelial-dependent E-selectin, but increased type 2 IL-4 and IL-13 expression. CONCLUSIONS: This study documents striking cytoprotective effects of virally induced IL-13 against hepatic I/R injury in two clinically relevant rat models of hepatic I/R injury. These data provide the rationale for novel therapeutic approaches to maximize the organ donor pool through the safer use of liver transplants despite prolonged periods of warm or cold ischemia, or both.

Adenoviridae↗
PubMed2003

Activation of alloreactive CD8+ T cells operates via CD4-dependent and CD4-independent mechanisms and is CD154 blockade sensitive.

CD154, one of the most extensively studied T cell costimulation molecules, represents a promising therapeutic target in organ transplantation. However, the immunological mechanisms of CD154 blockade that result in allograft protection, particularly in the context of alloreactive CD4/CD8 T cell activation, remain to be elucidated. We now report on the profound inhibition of alloreactive CD8(+) T cells by CD154 blockade via both CD4-dependent and CD4-independent activation pathways. Using CD154 KO recipients that are defective in alloreactive CD8(+) T cell activation and unable to reject cardiac allografts, we were able to restore CD8 activation and graft rejection by adoptively transferring CD4(+) or CD8(+) T cells from wild-type syngeneic donor mice. CD4-independent activation of alloreactive CD8(+) T cells was confirmed following treatment of wild-type recipients with CD4-depleting mAb, and by using CD4 KO mice. Comparable levels of alloreactive CD8(+) T cell activation was induced by allogenic skin engraftment in both animal groups. CD154 blockade inhibited CD4-independent alloreactive CD8(+) T cell activation. Furthermore, we analyzed whether disruption of CD154 signaling affects cardiac allograft survival in skin-sensitized CD4 KO and CD8 KO recipients. A better survival rate was observed consistently in CD4 KO, as compared with CD8 KO recipients. Our results document CD4-dependent and CD4-independent activation pathways for alloreactive CD8(+) T cells that are both sensitive to CD154 blockade. Indeed, CD154 blockade was effective in preventing CD8(+) T cell-mediated cardiac allograft rejection.

Animals↗
PubMed2003

Posttransplant administration of allochimeric major histocompatibility complex class-I-molecules induces true transplantation tolerance.

BACKGROUND: Allochimeric class-I major histocompatibility complex (MHC) molecules that contain donor-type immunogenic epitopes displayed on recipient-type sequences were shown to induce transplantation tolerance when administered at the time of transplantation. Here, we investigated the ability of posttransplant allochimeric administration to induce tolerance and concomitantly inhibit chronic rejection. METHODS: Allochimeric (alpha1h(1/u))-RT1.Aa class-I MHC antigenic extracts were administered by way of the portal vein into ACI recipients of Wistar-Firth (WF) hearts at days +3, +7, and +10 posttransplantation in conjunction with subtherapeutic oral cyclosporine. RESULTS: Delayed posttransplant allochimeric administration induced donor-specific transplantation tolerance to rat cardiac allografts. In contrast, delayed delivery of unaltered donor- or recipient-type MHC extracts failed to prolong allograft survival. In addition, histopathologic examination or estimation of transplant vascular sclerosis by neointimal index assessment, following delayed allochimeric therapy, revealed intact global architecture and minimal intimal thickening, respectively. CONCLUSION: Allochimeric MHC class-I therapy is a unique and novel clinically applicable approach for induction of "true" transplantation tolerance where chronic rejection is concomitantly abrogated.

Animals↗
PubMed2003

Randomized controlled trial of oral ganciclovir versus oral acyclovir after induction with intravenous ganciclovir for long-term prophylaxis of cytomegalovirus disease in cytomegalovirus-seropositive liver transplant recipients.

BACKGROUND: Without effective antiviral prophylaxis, cytomegalovirus (CMV) disease is a common cause of morbidity and mortality after liver transplantation. In this randomized, controlled trial, we compared the efficacy and safety of oral ganciclovir with oral acyclovir after induction with intravenous (IV) ganciclovir for long-term prophylaxis of CMV disease in CMV-seropositive liver transplant recipients. METHODS: Patients were initially administered IV ganciclovir at a dose of 6 mg/kg per day from day 1 to day 14 after transplantation followed by either oral ganciclovir (1 g every 8 hr) or oral acyclovir (800 mg every 6 hr) from day 15 to day 100 after transplantation. RESULTS: CMV disease occurred in only 1 of 110 patients (0.9%) receiving ganciclovir compared with 8 of 109 patients (7.3%) receiving acyclovir within the first year after transplantation (P =0.019). There was one case of CMV colitis in the ganciclovir group, whereas four cases of CMV syndrome, three cases of CMV pneumonia, and one case of CMV hepatitis developed in the acyclovir group. The only death from CMV disease occurred in an acyclovir-treated patient with CMV pneumonia. Both oral ganciclovir and oral acyclovir were generally well tolerated. Reversible leukopenia (decline in white blood cell count to <3.0 x 10(9)/L) was more common with oral ganciclovir (38/110 patients, 35%) than with oral acyclovir (20/109 patients, 18%) (P =0.009). The emergence of ganciclovir-resistant strains of CMV was not found during the study. CONCLUSIONS: A prophylactic regimen of 2 weeks of IV ganciclovir followed by an additional 12 weeks of oral ganciclovir is superior to a similar regimen of IV ganciclovir followed by oral acyclovir and almost completely eliminates CMV disease after liver transplantation. This superior protection against CMV disease extends up to 1 year after transplantation and is not associated with ganciclovir resistance.

Acyclovir↗
PubMed2003

Changing faces of liver transplantation: partial-liver grafts for adults.

The utilization of partial-liver grafts for transplantation of adults represents an evolution from strategies designed to increase pediatric organ supply that have been justified by increased organ-waiting times and morbidity of adult transplant candidates. These techniques, which include adult-to-adult living-donor and split-liver transplantation, mandate particular surgical and medical considerations, as partial-liver grafts predispose to unique complications resulting from anatomic variations, technical considerations, and recipient physiology. Adult-to-adult living-donor liver transplantation has been successfully reported throughout the world; however, the magnitude of the donor operation has resulted in serious morbidity and donor mortality that have stimulated an ethical debate as to the future of this procedure. The limitations encountered in the application of adult-to-adult, living-donor liver transplantation have renewed interest in the successful implementation of split-liver transplantation between two adults from one adult cadaver donor. This manuscript details current technical considerations for the performance of adult-to-adult living-donor and split-liver transplantation, summarizes current outcomes, and explores the ethical dilemma of living-donation.

Asia↗
PubMed2003

The conventional technique in in-situ split-liver transplantation.

Split-liver transplantation are innovative surgical techniques of graft creation that expand the cadaver donor pool and decrease reliance upon living-donation. To date, split-liver transplantation has been principally applied to pediatric recipients with excellent outcomes. Significant decreases in pediatric wait-list times, wait-list morbidity, and lower utilization of living-donation at centers that routinely implement split-liver transplantation have led to renewed interest in expanding these techniques to include two adult recipients from one adult cadaver donor. This article details technical considerations of the conventional in situ split procedure for the creation of a pediatric left lateral segment graft and an adult trisegment graft, and summarizes current outcomes.

Adult↗
PubMed2003

Carcinoid tumors of the common bile duct: report of two cases.

We report two cases of carcinoid tumors of the common bile duct. The first patient was a 65-year-old woman in whom a carcinoid tumor of the distal bile duct was incidentally found during an open cholecystectomy for cholecystitis. The second patient was a 27-year-old man in whom a distal common bile duct carcinoid was incidentally found during orthotopic liver transplantation for sclerosing cholangitis and multiple biliary strictures. There are few reports of carcinoid tumors of the extrahepatic ducts, and a brief review of the relevant literature is discussed following these case reports.

Adult↗
PubMed2003

A model to predict the development of mental status changes of unclear cause after liver transplantation.

Postoperative mental status changes are common after liver transplantation (LT). A clear cause of these mental status changes cannot be identified in a significant proportion of patients. In adult liver transplant recipients, our goals are to: (1) identify independent predictors for the development of post-LT mental status changes of unclear cause and (2) derive a practical formula to predict the risk for developing this complication by using simple clinical parameters. Eligible patients had documented mental status changes of at least 3 days' duration, occurring within 1 month of LT. Exclusion criteria were known structural brain disorders, major organ dysfunction, or metabolic causes of altered mentation. Age- and sex-matched controls were liver transplant recipients without post-LT neurological sequelae. Data were collected on preoperative, intraoperative, and postoperative variables. Univariate and multivariate analyses were performed to detect factors predictive of the development of post-LT mental status of unclear cause. There were 40 cases and 40 controls. Independent predictors of mental status changes of unclear cause included alcoholic and metabolic liver diseases; pre-LT mechanical ventilation; Model for End-Stage Liver Disease (MELD) score greater than 15; and nonelective LT. Using these four preoperative factors, a simple predictive rule was developed. Risk for developing altered mental status of unclear cause after LT was 78% to 89% if all four predictors were present versus 0.8% to 2.4% if no predictors were present. In conclusion, alcoholic and metabolic liver diseases, pre-LT mechanical ventilation, MELD score greater than 15, and nonelective LT are independent predictive factors for post-LT altered mental status changes of unclear cause. A simple model can be used to calculate the risk for developing altered mental status post-LT.

Case-Control Studies↗
PubMed2003

Fibronectin-alpha 4 beta 1 integrin-mediated blockade protects genetically fat Zucker rat livers from ischemia/reperfusion injury.

We tested a hypothesis that interactions between fibronectin (FN), the major extracellular matrix component, and its integrin alpha 4 beta 1 receptor is important in the development of ischemia/reperfusion injury of steatotic liver transplants. We examined the effect of connecting segment-1 (CS1) peptide-facilitated blockade of FN-alpha 4 beta 1 interaction in a well-established steatotic rat liver model of ex vivo cold ischemia followed by iso-transplantation. In this model, CS1 peptides were administered through the portal vein of steatotic Zucker rat livers before and after cold ischemic storage. Lean Zucker recipients of fatty liver transplants received an additional 3-day course of CS1 peptides after transplant. CS1 peptide therapy significantly inhibited the recruitment of T lymphocytes, neutrophil activation/infiltration, and repressed the expression of proinflammatory tumor necrosis factor-alpha and interferon-gamma. Moreover, it resulted in selective inhibition of inducible nitric oxide synthase expression, peroxynitrite formation, and hepatic necrosis. Importantly, CS1 peptide therapy improved function/histological preservation of steatotic liver grafts, and extended their 14-day survival in lean recipients from 40% in untreated to 100% in CS1-treated OLTs. Thus, CS1 peptide-mediated blockade of FN-alpha 4 beta 1 interaction protects against severe ischemia/reperfusion injury experienced otherwise by steatotic OLTs. These novel findings document the potential of targeting FN-alpha 4 beta 1 in vivo interaction to increase the transplant donor pool through modulation of marginal steatotic livers.

Animals↗
PubMed2003

Hepatic ischemia/reperfusion injury--a fresh look.

Ischemia/reperfusion (I/R) injury is a multifactorial process that affects graft function after liver transplantation. 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 cascade of deleterious cellular responses leading to inflammation, cell death, and ultimate organ failure. Increased experimental evidence has suggested 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 system is among the most critical of the cytoprotective mechanisms activated during cellular stress, exerting antioxidant and anti-inflammatory functions, modulating the cell cycle, and maintaining the microcirculation. Finally, the activation of toll-like receptors on Kupffer cells may play a fundamental role in exploring new therapeutic strategies based on the concept that hepatic I/R injury represents a case for a host "innate" immunity.

Animals↗
PubMed2003

Operative parameters that predict the outcomes of hepatic transplantation.

BACKGROUND: A growing discrepancy between the number of patients awaiting liver transplantation and the number of organs available mandates the use of even marginal organ donors in whom there is major risk of suboptimal graft function. A comprehensive analysis of operative parameters on the outcomes of liver transplantation has not been reported. STUDY DESIGN: We analyzed the impact of 24 operative variables on the survival of 942 consecutive primary liver allografts performed at a single center from June 1992 through December 1997. Univariate and Cox proportional hazards analysis was used to identify those variables with independent prognostic significance in graft survival. Resource utilization for variables with multivariate significance was also analyzed. RESULTS: Of 12 intraoperative variables found to have significance in univariate analysis, three were significant by Cox multivariate analysis: 1) lack of immediate bile production by the graft intraoperatively, 2) platelet transfusion > or = 20 U, and 3) recipient urine output < or =2.0 mL/kg/h intraoperatively. Each of the three variables was associated with marked increases in hospital and Intensive Care Unit length of stay and hospital charges accrued during the admission for transplantation. CONCLUSION: We identified three operative parameters that predict a poor outcome after liver transplantation. The presence of these indicators suggests that early retransplantation should be considered. Early identification of grafts likely to have poor function might also provide an opportunity for therapeutic intervention to salvage graft function.

Adult↗
PubMed2003

Discordance between ALT values and fibrosis in liver transplant recipients treated with ribavirin for recurrent hepatitis C.

Hepatitis C virus (HCV) recurrence is a serious problem after orthotopic liver transplantation (OLT). The role of ribavirin as a single agent to treat recurrent HCV is controversial. Our aim was to evaluate the correlation between alanine aminotransferase (ALT) levels and histological findings in OLT recipients treated with ribavirin monotherapy for recurrent HCV. The mean [+/- standard error (SE)] age of 11 patients was 50.1 (SE +/- 8.6) years. The estimated mean dose and duration of ribavirin treatment (+/- SE) was 661.5 (+/- 52.5) mg and 20.4 (+/- 1.7) months, respectively. Five patients required either dose reduction or erythropoietin. We found a significant decrease of mean (+/- SE) ALT value from 246 +/- 44.8 U/L to 109.4 +/- 49.1 U/L (p = 0.002) in patients treated with ribavirin. However, there was also significant worsening of interface activity (p = 0.03) and fibrosis (p = 0.02). No significant association was found between ALT values and (i) stage of hepatic fibrosis, (ii) interface activity, (iii) lobular activity and (iv) HCV RNA values. Our results suggest that HCV disease can progress despite a significant decrease in ALT values. ALT values are inadequate markers of the ribavirin monotherapy and can lead to erroneous conclusions of efficacy.

Adult↗
PubMed2003

Cytoprotective and antiapoptotic effects of IL-13 in hepatic cold ischemia/reperfusion injury are heme oxygenase-1 dependent.

Liver injury caused by ischemia/reperfusion (I/R) insult represents the major problem following orthotopic liver transplantation (OLT). I/R damage has been linked to Th1-like cytokine producers. This study evaluates putative cytoprotective effects/mechanisms of Th2-type IL-13 gene transfer. IL-13 overexpression prevented hepatic insult in a rat model of 24 h cold ischemia followed by OLT, as assessed: (i) profoundly decreased hepatocellular damage (sGOT levels), and ameliorated histological signs of I/R injury (Suzuki criteria), consistent with long-term OLT survival; (ii) prevented hepatic apoptosis (TUNEL stains) and up-regulated expression of antiapoptotic (A20, Bcl-2/Bcl-xl)/antioxidant (HO-1) genes. However, inhibition of HO-1 with tin protoporphyrin reversed cytoprotective/antiapoptotic effects of IL-13. In conclusion, cytoprotection rendered by virally induced IL-13 against hepatic I/R injury in this clinically relevant rat hepatic cold I/R injury model was accomplished via decreased apoptosis and induction of antiapoptotic/antioxidant molecules. HO-1 neutralization studies suggest that HO-1 represents one of putative IL-13 downstream effectors. This study provides the rationale for novel approaches to maximize organ donor pool through the safer use of OLTs despite prolonged periods of cold ischemia.

Animals↗
PubMed2003

Hepatitis C positive grafts may be used in orthotopic liver transplantation: a matched analysis.

Hepatitis C (HCV)-positive liver grafts have been increasingly used in patients with decompensated liver disease from HCV because of critical shortage of available organs. Fifty-nine recipients of HCV-positive grafts were matched to patients who received HCV-negative grafts. All recipients were transplanted for HCV liver disease. Matching variables were (1) status, (2) pre-transplant creatinine, (3) recipient age, (4) donor age, (5) warm ischemia time, and (6) year of transplantation. Both unmatched and matched analyses were performed on patient survival, graft survival, and time to HCV recurrence. There was no significant statistical difference in patient, graft, or HCV recurrence-free survival between recipients of HCV-positive and HCV-negative grafts with matched and unmatched analyses (p > 0.05). The 3-year estimates of HCV disease-free survival were 12% (+/- 9%) and 19% (+/- 7%) using HCV-positive and -negative grafts, respectively. The use of HCV-positive grafts in recipients with HCV does not appear to affect patient survival, graft survival, or HCV recurrence when compared with the use of HCV-negative grafts. Our results suggest that HCV-positive grafts can be used in a HCV liver transplant recipient.

Adult↗