Abstract: Stadlbauer V, Stiegler P, Müller S, Schweiger M, Sereinigg M, Tscheliessnigg KH, Freidl W. Attitude toward xenotransplantation of patients prior and after human organ transplantation. Clin Transplant 2010 DOI: 10.1111/j.1399-0012.2010.01296.x (c) 2010 John Wiley & Sons A/S. Abstract: Xenotransplantation is a potential strategy to overcome the shortage of human donor organs. As this technique has a major medical and psychological impact on patients and their family and friends, the attitude of patients currently waiting for organ transplantation is important. Therefore, we conducted a survey on the attitude toward xenotransplantation of patients on the waiting list and already transplanted patients. Patients received detailed information before being asked to fill in the questionnaire. We found that 65% would accept xenotransplantation, irrespective of gender, education level or if the patients were on the waiting list or already transplanted. The most common concern was transmission of diseases or genetic material, followed by psychological concerns and ethical issues. More patients had a positive attitude toward accepting cell or tissue transplantation when compared to whole organs. Pig pancreas islet cell transplantation is generally well accepted, patients with diabetes mellitus show even higher acceptance rates than patients without diabetes. In conclusion, xenotransplantation seems to be well accepted in patients who are potential future candidates for organ transplantation. Informing patients about the current status of research tended to decrease acceptance rates slightly.
Abstract: There is in vitro proof that mTOR proteins play a role in protecting HCV infected cells from apoptosis. The aim of this cohort study was to evaluate the effect of sirolimus as an mTOR inhibitor on hepatitis C recurrence in liver transplant recipients. Hepatitis C virus positive patients were followed prospectively regarding transaminases, immunosuppressive target levels, HCV RNA and influence of donor and recipient factors on viral recurrence and survival. Viral recurrence was defined as elevated liver enzymes combined with active hepatitis diagnosed on the basis of increasing viral load and/or biopsy-proven HCV relapse in the transplanted organ. Sixty-seven HCV positive patients were included: 39 received a regimen including sirolimus; 28 patients received calcineurin inhibitors. Sirolimus patients showed a significant decrease in the HCV PCR levels (p<0.05). Survival of the sirolimus patients was significantly higher (p<0.03) than in the other patient cohort. Sirolimus has been shown to be a potent immunosuppressive agent after liver transplantation, though nothing is known about its effect on HCV. This analysis suggests that sirolimus has potential to suppress viral recurrence in HCV positive liver transplant candidates.
Abstract: OBJECTIVE: With the increasing longevity of heart transplant recipients, the long-term effects of cyclosporine on renal function have become more evident. Highly sensitive, early, and effective monitoring of posttransplant renal function is still being researched. This study aimed to evaluate the prognostic value of cystatin C for patients after heart transplantation. METHODS: Seventy-three long-term recipients of a heart transplant more than 5 years before the study start were included in the analysis with a follow-up of 4 years. Serum creatinine, renal glomerular filtration rate calculated by the Modification of Diet in Renal Disease formula, and serum cystatin C levels were collected, and risk factors for renal dysfunction were assessed. Statistical analysis was performed for all patients. RESULTS: Univariate analysis showed a prognostic impact of antihypertensive medication and onset of diabetes (P < .001) on renal failure after transplantation. Multivariate analysis yielded cystatin C measured at the study start as a superior prognostic parameter for all time points (area under the receiver operating characteristic 12 months: 0.963; 24 months: 0.910; 48 months: 0.949) compared with the conventionally used creatinine levels. CONCLUSIONS: Our results showed an enormous potential of serum cystatin C as an early prognostic and easy to obtain biomarker for renal dysfunction after heart transplantation.
Abstract: BACKGROUND: After heart transplantation (HTx), endomyocardial biopsy (EMB) is currently the standard method to diagnose acute graft rejection. A non-invasive marker of rejection would be desirable as an alternative or to permit more selective use of the costly and invasive EMB. METHODS: In this retrospective study, outcomes of routinely taken EMBs were used to select 28 patients after HTx EMB Grade 0R (8 patients), 1R (9 patients) or 2R (11 patients). For these patients, myeloperoxidase (MPO) and carbonyl proteins (CP) in serum were measured using enzyme-linked immunoassay (ELISA). RESULTS: MPO and CP levels in post-HTx patients with Grade 2R rejection were significantly (MPO: p < 0.01; CP: p < 0.001) elevated at the time of rejection compared with levels 1 month earlier. MPO and CP levels predicted Grade 2R rejection and the best cut-off point was 237.5 mug/l for MPO and 222.5 pmol/mg for CP, respectively. Clinically most important was the marked increase (doubling of basic values within 1 month) of MPO and CP levels in cases of Grade 2R rejection in post-HTx patients. CONCLUSIONS: MPO and CP seem to be appropriate parameters to monitor rejection events non-invasively and to minimize the application of EMBs after HTx.
Abstract: INTRODUCTION: Mechanical stress and reagents used during the isolation and purification process as well as digestion time and temperature can alter the success of porcine islet cell (PIC) isolation. This study aimed to characterize the occurrence of isoprostanes during PIC isolation using a modified automated Ricordi method and to evaluate their influence on PIC isolation outcome. METHODS: Porcine pancreatic tissue was harvested at the local slaughter house, and 10 PIC isolations were performed using a modified automated Ricordi method. As positive controls for tissue damage-associated oxidative stress, six consecutive PIC isolations were performed in the presence of 1 mug lipopolysaccharide (LPS). PIC were purified by density gradient centrifugation using the Lymphoprep density gradient. Isoprostane measurement was performed using enzyme-linked immunosorbent assay. RESULTS: The final yield of viable and pure PICs in the experimental group was 3479 +/- 542 IEQ/g pancreas, and the LPS group yielded lower cell numbers compared to the experimental group. Isoprostane levels were significantly elevated in the LPS group as compared to the experimental group at all time points during the isolation from the beginning of the digestion process. DISCUSSION: PIC isolation and purification results significantly differed in the two experimental groups, underlining the negative effects of oxidative stress on PIC viability and purity, which impact negatively on PIC transplantation success.
Abstract: M. Schweiger, P. Stiegler, M. Scarpatetti, A. Wasler, M. Sereinigg, G. Prenner, K. Tscheliessnigg. Case of Paracoccus yeei infection documented in a transplanted heart.
Transpl Infect Dis 2010. All rights reserved Abstract: After a successful cardiac transplantation, routine endomyocardial biopsies showed severe infiltrates comparable with myocarditis. Polymerase chain reaction analysis of native myocardial samples revealed infection with Paracoccus yeei, and the clinical condition of the patient deteriorated. After administration of ciprofloxacin, his clinical condition improved, and further biopsies showed no infiltrates in the cardiac specimens. To our knowledge this is the first documented case of P. yeei infection in a heart transplant patient.
Abstract: INTRODUCTION: Organ preservation quality impacts porcine islet cell isolation and transplantation success. Among several preservation methods, the two-layer method is promising, but technically demanding and fails to deliver sufficient oxygen. The use of hyperbaric oxygenation may be an easier, more effective method to supply high partial pressure of oxygen (pO(2)) for organ storage. Therefore, the aim of this study was to test the capability of preoxygenation of various preservation solutions with HBO to maintain high pO(2) levels. METHODS: University of Wisconsin (UW), Custodiol, Perfadex, or Celsior solutions were preoxygenated in a pressure chamber. NaCl served as the control. pO(2) levels were measured at defined times. The oxygen storage capability was evaluated by leaving the storage bottles open for 2 minutes. RESULTS: It was feasible to preoxygenate preservation solutions. The best solution to maintain high pO(2) tensions was Perfadex, followed by Celsior, and UW. DISCUSSION: The greater the amount of oxygen in the preservation solution, the more oxygen can be delivered to the preserved pancreas. Further studies on the influence of preoxygenated preservation solutions on the porcine pancreas are warranted to improve organ quality, porcine islet cell isolation, and transplantation success.
Abstract: In this paper, a novel segmentation method for liver vasculature is presented, intended for numerical simulation of radio frequency ablation (RFA). The developed method is a semiautomatic hybrid based on multi-scale vessel enhancement combined with ridge-oriented region growing and skeleton-based postprocessing. In addition, an interactive tool for segmentation refinement was developed. Four instances of three-phase contrast enhanced computed tomography (CT) images of porcine liver were used in the evaluation. The results showed improved accuracy over common approaches and illustrated the method's suitability for simulation purposes.
