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A Shaked

Publications and source records attributed to A Shaked.

At least 19 recordsLinked to original sources
PubMed1997

Randomized controlled trial to evaluate flush and reperfusion techniques in liver transplantation.

To determine the impact of different flush and reperfusion techniques on postreperfusion syndrome (PRS) and postoperative graft function, 100 transplants were randomly assigned into four groups as follows: group 1 (n=31), portal vein flush, no vena caval venting; group 2 (n=21), hepatic arterial flush, no vena caval venting; group 3 (n=29), portal vein flush with vena caval venting; and group 4 (n=19), hepatic artery flush with vena caval venting. Donor and recipient characteristics were similar. Extensive intraoperative and postoperative monitoring was performed and measurements were documented immediately before reperfusion and at 1, 5, 15, and 30 min after reperfusion. PRS was defined by three criteria: mean arterial pressure (MAP) <60 mmHg at 1 min after reperfusion, MAP <60 mmHg at 5 min after reperfusion, and a decrease of 30% or more for the MAP percent area under the curve during the initial 5 min after reperfusion (%AUC). Using these definitions, the overall incidence of PRS was 21%, 8%, and 43%, respectively. Group 1 was the most hemodynamically stable; the incidence of PRS in group 1 was 2/31 (7%) at 1 min and 8/31 (25%) using %AUC criteria compared with 7/21 (33%) at 1 min and 12/21 (57%) using %AUC criteria for group 2 (P<0.05). The patients in groups 3 and 4 (vena caval venting) demonstrated smaller percentage increases in serum potassium levels (as determined by %AUC; 4.3+/-6.8 and 0.3+/-5.4, vs. 15.1+/-8.1 for group 1 and 22.9+/-8.2 for group 2). The difference between group 4 and group 2 was statistically significant (P<0.05). The increases in serum potassium did not translate into increased cardiac or hemodynamic instability. Combining all data obtained over the first 30 min after reperfusion, there was no statistically significant difference in hemodynamic or biochemical changes noted among the four groups. Postoperative liver function was similar among the four groups. We conclude that portal vein flush without vena caval venting provided a lower incidence of PRS than any other technique. Vena caval venting decreased the release of potassium into the circulation. Postoperative graft function was not significantly affected by flush and reperfusion techniques.

Adult↗
PubMed1997

Coccidioidomycosis in liver transplant patients.

Eight (0.59%) of 1,347 patients who underwent liver transplantation at the UCLA Medical Center (Los Angeles) developed coccidioidomycosis. Whereas only one case occurred during the first 8 years and 10 months of the UCLA Liver Transplant Program (February 1984 to December 1992), seven cases occurred within the following 23-month period (December 1992 to November 1994). The median time of onset for infection after transplantation was 8 weeks (range, 4-312 weeks). Clinical presentations of patients with coccidioidomycosis included pneumonia (six cases), pneumonia with meningitis (one case), hepatitis (one case), and monoarticular arthritis (one case). Despite therapy with amphotericin B alone (six cases) or amphotericin B plus fluconazole (two cases), infection was fatal in four of eight cases. As of this writing, the four surviving patients are receiving chronic maintenance therapy with either fluconazole (three patients) or itraconazole (one patient). These experiences show that coccidioidomycosis can be a serious and frequently fatal infection after liver transplantation and that the incidence of this disease appears to be increasing.

Adult↗
PubMed1996

Decreased alloreactivity to human islets secreting recombinant viral interleukin 10.

The objective of this study was to analyze allogeneic lymphocyte proliferative responses to cultured human pancreatic islets after gene transfer of viral interleukin (IL)-10 to the islets using replication-defective adenoviral vector. Human islets, either whole or dispersed into single cells, were cocultured with adenovector containing an expression cassette encoding the viral IL-10 gene under control of an SV40 promoter, this sequence replacing viral E1A and part of E1B early viral protein sequences. Subsequent production of recombinant protein by islets was determined by ELISA, and was found dependent on the multiplicity of infection (or ratio of vector to target cells). Protein was secreted by transfected islets at high levels 3-7 days after gene transfer. At high multiplicity of infection (100:1), islet viability was normal, but insulin secretion in response to glucose stimulation was blunted by 50%. Low-level recombinant viral IL-10 secretion by the islets was associated with increased allogeneic lymphocyte proliferation in mixed islet lymphocyte reactions. At protein levels in islet supernatant above 5 ng/ml, lymphocyte proliferation was significantly reduced. This pattern of viral IL-10 effect on lymphocyte proliferation correlated well with mixed lymphocyte reaction assays using purified protein. We conclude that transferred cytokine sequences are secreted by transfected islets as a function of the initial vector inoculum. The functional effect of the secreted cytokine viral IL-10 on allogeneic lymphocyte proliferation is dose dependent. Low-level recombinant protein secretion tended to augment lymphocyte proliferation, whereas high-level secretion significantly down-regulates this response.

Adenoviridae↗
PubMed1996

Adenovirus-mediated gene transfer in the transplant setting: early events after orthotopic transplantation of liver allografts expressing TGF-beta1.

We hypothesized that adenovirus mediated gene transfer of TGF-beta1 into liver grafts would enhanced local expression of this recombinant protein and down-regulate inflammatory and alloreactive immune response. A full length DNA encoding the murine TGF-beta1 was used to replaced the E1 region of adenovirus type 5 (AdmTGF-beta1). Expression and protein production of biologically active murine TGF-beta1 was tested in AdmTGF-beta1-transduced Hep G2 cells and TGF-beta-sensitive MV1 cells. In the transplant setting, the replication-defective vector was used to perfused cold preserved ACI liver allograft prior to transplantation into Lewis recipients. Control livers were similarly perfused with cold lactated Ringer's solution and were followed without immunosuppression. Animals were sacrificed at 1, 3, and 5 days after transplantation. Intragraft cytokine levels of TNFalpha, and IFNgamma were determined using ELISA and quantitative PCR. TGF-beta1 ELISA of culture supernatants from AdmTGF-beta1 transduced hepatocyte cell line Hep G2 excreted TGF-beta1 in quantities directly correlated with multiplicity of infection (MOI, vector:hepatic cell ratio). The biological activity of the excreted recombinant protein was confirmed by growth inhibition of MV1 TGF-beta-sensitive cells. Enhanced production of TGF-beta1 in transduced allografts was associated with decreased levels of TNFalpha and IFNgamma when compared with nonimmunosuppressed controls. Adenovirus-mediated gene transfer of murine TGF-beta1 into hepatic cells results in the expression of biologically active protein. Transduction of allografts with TGF-beta1 down-regulates TNFalpha and IFNgamma production early after orthotopic transplantation. Graft transduction with TGF-beta1 offers a novel approach to study the effects of single immune modulator on alloreactive immune response, T cell function, and cytokine cascade.

Adenoviridae↗
PubMed1996

Rapid en bloc technique for pancreas-liver procurement. Improved early liver function.

It is our experience that warm dissection in the porta hepatis as well as extensive organ mobilization during combined pancreas-liver procurements may cause posttransplant dysfunction of the liver. To avoid this, we recently utilized a rapid en bloc procurement technique with minimal warm dissection and division of the liver and pancreas ex vivo. Fifteen procurements were performed using this rapid en bloc technique; seventeen procurements involved extensive dissection followed by sequential in situ procurement of the liver and pancreas grafts. The control group consisted of 15 age-matched patients who received livers when no pancreas was harvested. Dissection time was 157 +/- 13 min (mean +/- SEM) in the in situ group, 78 +/- 3 min in the en bloc group (P<0.02), and 51 +/- 6 min in the liver only group (P<0.02). There was no difference in donor age, cold ischemia time, or recipient United Network for Organ Sharing status. Pancreata obtained using the en bloc technique all had immediate function and there were no episodes of acute pancreatitis. Early liver graft function, as assessed by lactate dehydrogenase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, and total bilirubin levels, was significantly lower in the en bloc and liver only group when compared with the in situ group. The total hospital stay was also significantly lower in these groups. We conclude that the rapid en bloc technique decreases operative time during the donor operation. Procurement-related injury to the liver graft is minimized without compromising pancreas graft function.

Adult↗
PubMed1996

Improved results of liver transplantation in patients with portal vein thrombosis.

OBJECTIVE: To analyze the impact of preexisting portal vein thrombosis (PVT) on the operative management and outcome of liver transplantation. DESIGN: Retrospective review of 1423 patients who received transplants over 11 years. SETTING: Tertiary referral center. PATIENTS OR OTHER PARTICIPANTS: Seventy patients who underwent liver transplantation who had preexisting PVT. INTERVENTIONS: Portal vein thromboendovenectomy, vein grafting, or use of portal collateral veins for inflow during liver transplantation. MAIN OUTCOME MEASURES: Postoperative PVT, intraoperative transfusion, retransplantation rate, 30-day and 1-year actuarial survival rates. RESULTS: Operative management consisted of thromboendovenectomy in 61 cases, vein graft to the superior mesenteric vein in 6 cases, and vein graft to other mesenteric veins in 3 cases. The incidence of posttransplant PVT was 3% (n = 2). The mean +/- SD transfusion requirement was 23 +/- 18 U. The 1-year actuarial survival rate was 74% but improved from 66% in the first 35 cases to 82% in the latter 35 cases. CONCLUSIONS: Thromboendovenectomy is the procedure of choice for PVT. Results of liver transplantation in patients with PVT improve significantly with experience gained and are equivalent to results in patients without PVT.

Actuarial Analysis↗
PubMed1996

Viral IL-10 gene therapy inhibits TNF-alpha and IL-1 beta, not IL-6, in the newborn endotoxemic mouse.

INTRODUCTION: Modulation of the inflammatory cascade within the liver of critically ill infants may improve the chance of survival. Using gene therapy, the authors hypothesized that augmented local production of the counter-regulatory cytokine viral interleukin-10 (IL-10) in vivo will modulate the critical cytokines in the inflammatory response. The purpose of the present study was to determine whether replication-defective adenovirus-mediated viral IL-10 (vIL-10) gene transfer and expression within the liver can achieve this goal in newborn mice. MATERIALS AND METHODS: Four-week-old Balb/c mice were administered (intraperitoneally) 1 x 10(9) plaque-forming units (pfu) per milliliter of an adenovirus vector (E1a/b-deleted) than encodes the sv40 promoter and the BCRF1 cDNA, or of control vector dl434 that expresses no foreign gene. Forty-eight hours later the mice were challenged with 50 micrograms/kg of lipopolysaccharide (LPS) they were killed 1, 2, 6, or 24 hours later (six at each time point). Southern blot analysis was performed on genomic DNA isolated from the liver, lung, and kidney to assess gene transfer of BCRF1. Homogenized liver protein was analyzed for tumor necrosis factor-alpha (TNF-alpha), IL-1 beta, IL-6, and recombinant vIL-10. RESULTS: Southern blot analysis confirmed successful gene transfer to the liver but not to the lung, kidney, or dl434-transduced liver in mice that received adenovectors. Viral IL-10 levels within the liver ranged from 14 to 18 ng/mL. In controls, TNF-alpha production was elevated at early time points, to 18,000 pg/mL, but decreased rapidly by 24 hours after LPS challenge. The TNF-alpha levels of animals treated with Ad5svBCRF1 were significantly lower than those of controls throughout the course of study (P < .0001). After the LPS challenge, hepatic IL-1 beta decreased, from a maximum of 800 pg/mL (2 hours) to 411 pg/mL (24 hours). Inhibition of IL-1 beta by vIL-10 occurred at 1 hour (P > .016) and 2 hours (P < .001) only. Hepatic production of IL-6 after LPS challenge ranged from 7 to 8,000 pg/mL in all groups and was not altered by vIL-10 gene therapy. CONCLUSION: In vivo administration of adenovectors encoding BCRF1 to newborn mice results in efficient hepatic transduction and expression of recombinant vIL-10. The Kupffer cell response to LPS is suppressed with respect to TNF-alpha and IL-1 beta, but not IL-6. In vivo modulation of hepatic cytokine responses is achievable using gene products that mimic cellular cytokines. This is an effective model for the selective evaluation of therapeutic gene products for gene therapy of sepsis.

Animals↗
PubMed1996

Determination of the presence of interleukin-6 in bile after orthotopic liver transplantation. Its role in the diagnosis of acute rejection.

OBJECTIVE: The authors evaluated the significance of interleukin-6 (IL-6) in bile in the diagnosis of acute rejection after liver transplantation. SUMMARY BACKGROUND DATA: Interleukin-6 in blood has not been shown to be useful as a marker of acute rejection in clinical liver transplantation. In a rat liver transplantation model, the authors have found that bile IL-6 levels correlated well with the severity of rejection as determined histologically, whereas kinetics of serum IL-6 differed among rats without any definite feature related to graft rejection. METHODS: Fifty-one patients who underwent orthotopic liver transplantation between May 1990 and February 1991 at the University of California, Los Angeles, were included in the study. After liver transplantation, bile and blood were collected daily, and IL-6 levels were measured by the enzyme-linked immunosorbent assay. RESULTS: Bile IL-6 increased to 1228 +/- 317 pg/mL on the day of transplantation and decreased to 50 pg/mL or less within 48 hours. Patients who had uneventful postoperative courses had low levels of bile IL-6 throughout their hospitalization. In patients with acute rejection, bile IL-6 significantly increased (1090 +/- 990 pg/mL; p<0.05), but decreased in response to antirejection therapy. In patients who had liver dysfunction due to ischemic change or sepsis, bile IL-6 did not increase. Patients with cholangitis had significantly increased levels of bile IL-6 (146 +/- 47; p<0.05). Interleukin-6 in blood increased with many kinds of complications other than rejection and seemed to be less specific than that in bile. CONCLUSIONS: Measurement of IL-6 in bile may be a useful, noninvasive tool for diagnosing acute rejection.

Acute Disease↗
PubMed1996

Adenoviral-p53 gene transfer to orthotopic and peritoneal murine bladder cancer.

PURPOSE: This study was designed to examine the potential for adenoviral-mediated gene therapy in primary and metastatic bladder cancer. MATERIALS AND METHODS: Orthotopic and intraperitoneal bladder tumors were established after delivery of 1 x 10(6) MBT-2 cells into syngeneic mice. Gene transfer was accomplished via intravesical or intraperitoneal instillation by using an E-1 deleted adenovirus encoding LacZ or human p53. Successful tumor transduction was confirmed in tumor DNA and mRNA by polymerase chain reaction. Detection of recombinant gene product was detected by histochemical staining (X-gal) and Western blot. RESULTS: Palpable tumors developed 18 days following implantation. LacZ and p53 mRNA were present in tumor and adjacent normal tissue after bladder and intraperitoneal vector administration. Recombinant gene products were identified by histochemistry and Western blot. CONCLUSION: Bladder tumor-directed gene transfer using adenoviral vectors is an efficient and powerful tool for evaluating the adjuvant role of therapeutic gene products.

Adenoviridae↗
PubMed1996

Etiology and management of symptomatic adult hepatic artery thrombosis after orthotopic liver transplantation (OLT).

Hepatic artery thrombosis (HAT) after adult orthotopic liver transplantation (OLT) is associated with fulminant sepsis and irretrievable loss of the graft. The purpose of this study was 1) to identify recipients at risk for the development of HAT; 2) to define early signs and methods for diagnosis; 3) to determine surgical treatment strategies following diagnosis of HAT. The charts of 680 adults who underwent primary OLT were reviewed. Eleven patients were symptomatic from HAT. Operative data revealed problematic arterial reconstruction in 9/11, and were related to inadequate recipient inflow, necessitating an interposition allogeneic iliac graft in seven patients, or anastomosis to aberrant right hepatic artery in two recipients. Early HAT in 4/11 occurred within 4 weeks after transplantation, whereas late thrombosis in 7/11 was identified 30 days to 1 year after OLT. The postthrombosis course was manifested by elevated liver transaminases (7/11), sepsis and recurrent cholangitis (9/11), or gas gangrene of the liver (4/11). The treatment modalities included thrombectomy and revision of the arterial anastomosis (1/11), emergency hepatectomy with temporary portocaval shunt (2/11), and urgent retransplantation (5/11). Antibiotic therapy and elective retransplantation was the treatment in 4/11. Overall 1-year patient survival and satisfactory graft function was 45 percent.

Adult↗
PubMed1995

Long-term ganciclovir prophylaxis eliminates serious cytomegalovirus disease in liver transplant recipients receiving OKT3 therapy for rejection.

We conducted a trial of long-term ganciclovir prophylaxis for prevention of cytomegalovirus (CMV) disease in liver transplant recipients receiving OKT3 therapy for rejection. Intravenous ganciclovir (6 mg/kg once a day, Monday through Friday) was initiated on the same day OKT3 therapy was started and continued for 4 or more weeks. Fifty-one consecutive adult patients (80% CMV seropositive, 20% CMV seronegative) were evaluated. Due to the patient's noncompliance or the primary physician's decision, 6 patients received less than 2 weeks of ganciclovir. Three of these 6 (50%) developed CMV disease (hepatitis 1, CMV syndrome 2). In contrast, of 45 patients receiving 4 or more weeks of prophylactic ganciclovir, only 1 (2.2%) developed CMV disease (hepatitis). There were no cases of CMV disease among 29 patients who received 6 or more weeks of ganciclovir. Reversible neutropenia in 2 patients (4.4%) was the only side effect associated with long-term ganciclovir. Complications from central intravenous catheters did not occur. These results suggest that CMV can be eliminated as a significant pathogen in liver transplant recipients receiving OKT3 for rejection by the long-term administration of prophylactic gnaciclovir, which is safe.

Adult↗
PubMed1995

Correlation between donor age and the pattern of liver graft recovery after transplantation.

We have observed an increased rate of delayed nonfunction (DNF) of liver grafts procured from older donors. The aim of this study was to correlate donor age and the patterns of graft failure after transplantation. Pattern of liver injury, synthetic function, and graft survival in recipients receiving liver grafts from donor older than age 50 (group I, n = 95) were compared with matched cohort of recipients transplanted with grafts from donors age 20-30 (group III, n = 50). Primary nonfunction (PNF) of the graft was defined as non-recoverable hepatocellular function necessitating emergency retransplantation within 72 hr. DNF was defined as marginal graft function necessitating retransplantation within one month. Recipient characteristics, including age and preoperative UNOS status, were similar between groups. Ischemic/reperfusion injury, reflected by SGOT and SGPT was more severe in older donors. PNF occurred at similar frequencies for all groups (7%). Normal liver function was regained in 76% of recipients in group I, and in 92% in group II. However, cholestatic pattern was observed in recipient of grafts from group I donors. Rapid rise in bilirubin, despite normalization of prothrombin time and liver transaminases, was the hallmark of DNF. DNF resulted in higher retransplantation rate in group I (24% vs. 8% in group II). Donor age did not affect patient survival. Liberalizing criteria for donor selection, and acceptance of older donors is a calculated risk. Over 75% of the recipients will regain normal liver function. However, a higher number of these grafts will exhibit slow recovery after transplantation, and a significant rate of DNF. Recognition of such pattern and early retransplantation should decrease mortality.

Adult↗
PubMed1995

Biliary tract complications after orthotopic liver transplantation. Endoscopic approach to diagnosis and therapy.

This study was undertaken to further define the role of endoscopic methods in the evaluation and treatment of biliary tract complications after liver transplantation and to determine the efficacy and safety of this approach. Fifty liver transplant patients were referred for endoscopic evaluation of a suspected biliary tract complication. Two patient groups were identified based on the indication for the endoscopic retrograde cholangiopancreatography (ERCP): Group 1 was suspected of having biliary fistula and group 2 was suspected of having bile duct obstruction. Group 1 consisted of 35 patients who developed bile peritonitis after inadvertent migration of the T-tube or intentional T-tube removal. Group 2 consisted of 15 patients who developed cholestatic hepatic chemistries in the absence of allograft rejection on liver biopsy. ERCP identified a biliary fistula at the T-tube insertion site into the bile duct in 32 (91%) group 1 patients. Twenty-six of 26 treated with a nasobiliary tube had fistula closure at a mean 5.2 days. Five of 6 treated with a stent, with or without sphincterotomy, had no leak at the time of stent removal (mean, 45 days). ERCP identified a cause for the cholestatic hepatic chemistries in 11 (73.5%) group 2 patients, including bile duct stones (n = 4), anastomotic (n = 3) or intrahepatic (n = 2) strictures, bile duct necrosis (n = 1), and hemobilia (n = 1). Five of the 5 patients undergoing endoscopic therapy were treated successfully. The endoscopic complication rate was 4% and the 30-day mortality rate was 2%. During a mean follow-up of 15 months, 94% of the patients who were treated successfully had no recurrent biliary tract disease. The results of this study suggest that ERCP is an effective modality in the evaluation of patients with suspected biliary tract complications after liver transplantation. In selected patients, endoscopic therapy obviates the need for additional surgical or percutaneous intervention.

Adult↗
PubMed1995

Randomised comparison of ganciclovir and high-dose acyclovir for long-term cytomegalovirus prophylaxis in liver-transplant recipients.

Despite current approaches to prophylaxis, cytomegalovirus (CMV) continues to be a common cause of infection and disease in solid-organ-transplant patients. Thus, we conducted a controlled trial comparing long-term administration of ganciclovir with high-dose acyclovir for prevention of CMV infection and disease in liver transplant recipients. At the time of transplant, patients were randomised to receive either ganciclovir (6 mg/kg body weight per day intravenously from postoperative day 1 to day 30, then 6 mg/kg per day Monday through Friday until day 100) or acyclovir (10 mg/kg intravenously every 8 h from postoperative day 1 to day of discharge, then 800 mg orally four times a day until day 100). Patients were followed for development of CMV infection, CMV disease, and drug-related toxicity by frequent cultures, serological tests, laboratory measurements, and tissue biopsies. During the first 120 days after transplant, CMV infection occurred in 48 of 126 (38%) acyclovir patients but in only 6 of 124 (5%) ganciclovir patients (p < 0.0001). Similarly, symptomatic CMV disease developed in 12 of 126 (10%) acyclovir patients but in only 1 of 124 (0.8%) ganciclovir patients (p = 0.002). Ganciclovir reduced the incidence of CMV infection in both CMV antibody positive (37 vs 4%, p = 0.001) and negative patients (42 vs 11%, p = 0.06). In a multivariate analysis of donor-recipient CMV antibody status and other risk factors, prophylactic ganciclovir was the most significant factor protecting against CMV infection (p < 0.0001) and disease (p = 0.001). Ganciclovir and acyclovir were generally well-tolerated. Incidences of leukopenia, thrombocytopenia, renal failure, and other adverse events were similar in the two groups. CMV can be eliminated almost completely as a significant pathogen in liver transplant recipients by the long-term administration of prophylactic ganciclovir. In addition, the treatment is safe.

Acyclovir↗
PubMed1995

Multiple vectors effectively achieve gene transfer in a murine cardiac transplantation model. Immunosuppression with TGF-beta 1 or vIL-10.

The application of gene transfer techniques to organ transplantation offers the potential for modulation of immunity directly within an allograft without systemic side effects. Expression vectors and promoter elements are important determinants of gene transfer and expression. In this study, various vectors (naked plasmid DNA, retroviral vector, herpes simplex viral vector, and adenoviral vector) with various promoters (RSV-LTR, SV40, MuLV-LTR, HCMVie1) were directly compared to demonstrate the successful gene transfer and expression of beta-galactosidase in murine myoblasts in vitro and within murine heterotopic, nonvascularized cardiac isografts or allografts in vivo. Expression of transferred genes was not toxic to cells and strength of expression varied according to the type of vector. Plasmid DNA was expressed in myocytes, retroviral vector was expressed in the graft infiltrating cells, and herpes simplex and adenoviral vectors were expressed in both myocytes and graft-infiltrating cells. Preliminary studies evaluated the ability of these vectors to deliver immunologically important signals. Allografts injected with pSVTGF-beta 1, a plasmid-encoding transforming growth factor beta 1 (TGF-beta 1) under the control of the SV40 promoter, showed significant prolongation of graft survival of 26.3 +/- 2.5 days compared with 12.6 +/- 1.1 days for untreated allografts, and 12.5 +/- 1.5 days for the allografts injected with control plasmid (P < 0.05). Allografts injected with MFG-vIL-10, a retroviral vector encoding viral interleukin-10 under the control of the MuLV-LTR, showed prolongation of graft survival of 36.7 +/- 1.3 days versus 12.6 +/- 1.1 days for the untreated allograft, and 13.5 +/- 2.0 days for the allografts injected with control retroviral vector (P < 0.001). Both vectors were transcriptionally active in vivo and did not appear to have toxic effects. Gene therapy for transplantation can induce transient expression of immunologically relevant molecules within allografts that impede immune activation while avoiding the systemic toxicity of conventional immunosuppression.

Animals↗
PubMed1995

Adenovirus-mediated gene transfer in the transplant setting. Part III. Variables affecting gene transfer in liver grafts.

We have established a system of efficient gene transfer to liver grafts using adenovirus vectors. The purpose of this study was to examine variables affecting gene transfer to rat liver grafts during cold preservation. Our results demonstrate that gene transfer efficiency was directly correlated with the ratio of vector to hepatic cells (multiplicity of infection [MOI] and the length of exposure to the vector. At MOIs of 10:1 and 50:1, the hepatic cell transduction rate was 25-30% and 100%, respectively. However, higher MOI was associated with significant mortality. Prolonging the cold preservation/exposure time resulted in an increased transduction rate (50% at MOI of 10:1). Similar gene transfer efficiencies were observed when the vector was diluted in lactated Ringer's or University of Wisconsin solution. Recombinant protein production was evident within 12 hr after reperfusion, and increased to a peak level within 48 hr. These results suggest a predictable pattern of gene transfer and expression after ex vivo transduction of liver grafts with adenovirus vectors. These data are essential in directing desirable levels of recombinant protein within the transplanted organ.

Adenoviridae↗