PubMed Health⌕ Search

Biomedical subjects

E Mor

Publications and source records attributed to E Mor.

At least 19 recordsLinked to original sources

Switching from tacrolimus to sirolimus halts the appearance of new sebaceous neoplasms in Muir-Torre syndrome.

Little is known about the effects of immunosuppression on patients with hereditary nonpolyposis colorectal cancer (HNPCC). We describe a kidney transplant recipient with unrecognized Muir-Torre syndrome in whom the administration of a tacrolimus-based regimen led to the eruption of multiple sebaceous tumors. The patient was later found to harbor an MSH2 mutation. Switching to a sirolimus-based regimen resulted in arrest of the disease. When the patient was switched back to tacrolimus, new facial lesions rapidly appeared. Switching again to sirolimus resulted again in halting the appearance of new lesions. This finding is in line with the known antiangiogenic activity of sirolimus and reports on the regression of cutaneous Kaposi's sarcoma in kidney transplant recipients switched from another immunosuppressive regimen to sirolimus. Further studies on the potential use of sirolimus for the treatment of de novo tumors in immunosuppressed kidney transplant recipients with HNPCC are warranted.

Adenoma↗

Cathepsin B inactivation attenuates the apoptotic injury induced by ischemia/reperfusion of mouse liver.

BACKGROUND: A major mechanism underlying warm ischemia/reperfusion (I/R) injury during liver transplantation is the activation of the caspase chain, which leads to apoptosis. Recently, it was demonstrated that the release of cathepsin B, a cysteine protease, from the cytosol in liver injury induces mitochondrial release of cytochrome c and the activation of caspase-3 and -9, thereby leading to apoptosis. The aim of this study was to ascertain if cathepsin B inactivation attenuates the apoptotic injury due to I/R in mouse liver. METHODS: A model of segmental (70%) hepatic ischemia was used. Eighteen mice were anesthetized and randomly divided into three groups: (1) CONTROL GROUP: sham operation (laparotomy); (2) Ischemic group: midline laparotomy followed by occlusion of all structures in the portal triad to the left and median lobes for 60 min (ischemic period); (3) STUDY GROUP: like group 2, but with intraperitoneal administration of a pharmacological inhibitor of cathepsin B (4 mg/100 g) 30 min before induction of ischemia. Serum liver enzyme levels were measured by biochemical analysis, and intrahepatic caspase-3 activity was measured by fluorometric assay; apoptotic cells were identified by morphological criteria, the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) fluorometric assay, and immunohistochemistry for caspase-3. RESULTS: Showed that at 6 h of reperfusion, there was a statistically significant reduction in liver enzyme levels in the animals pretreated with cathepsin B inhibitor (p<0.05). On fluorometric assay, caspase-3 activity was significantly decreased in group 3 compared to group 2 (p<0.0001). The reduction in postischemic apoptotic hepatic injury in the cathepsin B inhibitor -treated group was confirmed morphologically, by the significantly fewer apoptotic hepatocyte cells detected (p<0.05); immunohistochemically, by the significantly weaker activation of caspase-3 compared to the ischemic group (p<0.05); and by the TUNEL assay (p<0.05). CONCLUSION: The administration of cathepsin B inhibitor before induction of ischemia can attenuate postischemic hepatocyte apoptosis and thereby minimize liver damage. Apoptotic hepatic injury seems to be mediated through caspase-3 activity. These findings have important implications for the potential use of cathepsin B inhibitors in I/R injury during liver transplantation.

Animals↗

Percutaneous balloon dilatation for the treatment of early and late ureteral strictures after renal transplantation: long-term follow-up.

We report our experience with percutaneous balloon dilatation (PBD) for the treatment of ureteral strictures in patients with renal allografts. Of the 422 consecutive patients after renal transplantation in our center 10 patients had ureteral strictures. An additional 11 patients were referred from other centers. The 21 patients included 15 men and 6 women aged 16 to 67 years. Strictures were confirmed by sonography and scintigraphy in all cases. Patients underwent 2 to 4 PBDs at 7-10-day intervals. Clinical success was defined as resolution of the stenosis and hydronephrosis on sequential ultrasound and normalization of creatinine levels. Patients were divided into two groups: those who underwent transplantation more than 3 months previously and those who underwent transplantation less than 3 months previously. PBD was successful in 13 of the 21 patients (62%). There was no statistically significant difference in success rate between the patients with early (n = 12) and those with late (n = 9) obstruction: 58.4% and 66%, respectively. No major complications were documented. PBD is a safe and simple tool for treating ureteral strictures and procedure-related morbidity is low. It can serve as an initial treatment in patients with early or late ureteral strictures after renal transplantation.

Adolescent↗

Experience with lamivudine therapy for hepatitis B virus infection before and after liver transplantation, and review of the literature.

OBJECTIVES: To analyse the results of lamivudine therapy on suppression of hepatitis B virus (HBV) replication before transplantation and on preventing graft reinfection postoperatively. DESIGN: Long-term clinical study. SETTING: Liver Institute and Department of Transplantation of a tertiary-care university-affiliated centre. SUBJECTS: (1) 14 candidates for liver transplantation with decompensated liver disease caused by active replication of HBV; (2) six patients with recurrent HBV infection after transplantation. INTERVENTION: Lamivudine 100 mg daily; administered in group 1 before surgery and continued after in nine patients who underwent transplantation; administered in group two postoperatively only. anti-hepatitis B surface antigen immunoglobulin (HBIg) was administered postoperatively in both groups. MAIN OUTCOME MEASURES: Immunoassay evaluation of serum hepatitis B surface antigen, serum hepatitis Be antigen and serum HBV DNA (hybridization and PCR); sequencing through the tyrosine-methionine-aspartate-aspartate locus of the HBV polymerase gene in patients with lamivudine breakthrough; inflammation and fibrosis scoring on liver biopsy before and at least 2 years after lamivudine therapy in group 2. RESULTS: Pretransplantation therapy (group 1) significantly suppressed HBV replication and enabled nine patients (64.2%) to undergo transplantation. Only one patient (7.1%) had lamivudine breakthrough, and one (7.1%) had recurrent HBV. Lamivudine administration begun after transplantation (mean 48.0 months, range 30-60 months) because of graft reinfection (group 2) was associated, over the long-term, with the emergence of high mutation rates (83.3%), histological disease progression (66.6%), and hepatic failure (33.3%). CONCLUSIONS: In patients with chronic HBV infection and active viral replication, lamivudine therapy is effective when started before transplantation. However, its long-term administration after transplantation for recurrent HBV leads to high resistance rates. Combination therapy with lamivudine and HBIg immunoglobulin can substantially reduce the recurrence rate. Further studies on combination antiviral therapy are needed in this patient population.

Antiviral Agents↗

Defibrotide for the treatment of veno-occlusive disease after liver transplantation.

BACKGROUND: Veno-occlusive disease (VOD) after liver transplantation is associated with acute rejection and poor outcome. The use of antithrombotic and thrombolytic agents is limited by their toxicity. Defibrotide is a polydeoxyribonucleotide with thrombolytic and antithrombotic properties and no systemic anticoagulant effect. METHODS: Defibrotide, 35-40 mg/kg/day, was administered intravenously for 21 days on a compassionate-use basis to two patients aged 66 and 49 years. VOD had developed 6 weeks and 4 months after orthotopic liver transplantation for hepatitis C and hepatitis B infection, respectively. VOD was diagnosed clinically by findings of weight gain (8.5% and 16%), ascites, jaundice (serum bilirubin 5.4 mg/dl and 21.7 mg/dl), and severe coagulopathy (in one patient), and histologically by the presence of hemorrhagic centrilobular necrosis and fibrous stenosis of the hepatic venules. One of the patients had received azathioprine as part of the immunosuppressive regimen. There was no evidence of acute cellular rejection histologically. RESULTS: After 3 weeks of defibrotide administration, the first patient showed complete clinical resolution of the VOD, and serum bilirubin level normalized. He is alive 6 months after transplantation. The second patient, treated at a later stage of disease, showed marked improvement in the coagulopathic state, but there was no resolution of the VOD. He died 2 months later of multiorgan failure due to Escherichia coli sepsis. Neither patient had side effects from the drug. CONCLUSIONS: Defibrotide is a promising drug for the treatment of VOD after liver transplantation and needs to be evaluated in large, prospective studies.

Aged↗

Primary hyperoxaluria type 1: improved outcome with timely liver transplantation: a single-center report of 36 children.

BACKGROUND: The appropriate use of liver transplantation in children with type-1 primary hyperoxaluria (PH-1) is not well established. We reviewed our experience with 36 children with PH-1, including 12 who underwent liver transplantation. PATIENTS AND METHODS: From 1989-1998, 36 children from 10 families in northern Israel were diagnosed with PH-1. Eight children presented with renal failure; seven of these eight had the severe infantile form of the disease. One child was treated with kidney transplantation alone. Combined liver-kidney transplantation has been performed in nine children and preemptive liver transplantation in three children. A review of the patients' charts for the following parameters was performed: age, clinical signs, and renal sonographic findings at diagnosis, age at onset of dialysis, and current status. Type of transplant, pre- and posttransplant urine oxalate excretion, current renal function, survival, and complications were recorded in liver recipients. RESULTS: Of the 23 nontransplanted children, 9 died of complications related to severe systemic oxalosis and 14 are alive (mean follow-up, 7.4 years), including 2 who are candidates for transplantation. The child who underwent only kidney transplantation died of unrelated causes. Of the 12 liver recipients, 2 died within the first 3 months posttransplant and another child underwent retransplantation due to hepatic arterial thrombosis. At intervals after transplant ranging from 6-54 months, 10 recipients are alive (7 of the 9 recipients of combined liver-kidney transplants and all 3 recipients of preemptive liver transplants). Mean GFR in the 10 survivors is 77 ml/min/m2. In 9 of these 10, daily urinary oxalate excretion normalized. Renal function has improved (mean GFR 86 vs. 58 ml/min/m2) but renal oxalate deposits remain in the three recipients of isolated liver grafts. CONCLUSIONS: Our decade-long experience with children with PH-1 supports strategies for early diagnosis and timely liver transplantation. Preemptive isolated liver transplantation should be considered in children who develop the disease during infancy or in those with slowly progressive disease when significant symptoms develop. Combined liver-kidney transplantation is suggested for children with end-stage renal disease.

Adolescent↗

Efficacy of lamivudine for the treatment of hepatitis B virus infection after liver transplantation in children.

BACKGROUND: There is at present very little information about hepatitis B virus (HBV) infection in children after liver transplantation. This is the first study to assess the safety and efficacy of lamivudine in this patient population. METHODS: We describe three children aged 5-14 years who underwent liver transplantation for fulminant hepatitis A, hyperoxaluria, and cystic fibrosis. Despite adequate immunoprophylaxis, two of the children who were serum hepatitis B surface antigen-positive before transplantation (HBV DNA-negative by hybridization) had a reactivation of the disease, and one had a de novo HBV infection, at 12-18 months after transplantation. Lamivudine 3 mg/kg was administered on a compassionate-use basis for 14-36 months. RESULTS: After 1 month of therapy, HBV DNA disappeared from the serum in all patients by hybridization and in two patients by polymerase chain reaction. In all three children, alanine transaminase levels normalized. One child developed lamivudine resistance after 22 months with no evidence of hepatic decompensation. Repeated liver histological studies revealed progression of hepatic fibrosis in one child. All children remained serum hepatitis B surface antigen- and hepatitis B e antigen-positive. No adverse effects of the drug were noted. CONCLUSION: Lamivudine is beneficial and well tolerated in children with HBV infection after liver transplantation.

2-Aminopurine↗