Immunohistochemical and radiological characterization of wound healing in porcine liver after radiofrequency ablation.

BACKGROUND: Radiofrequency ablation (RFA) is a minimal invasive therapeutic option for patients with hepatocellular carcinoma or liver metastases. We investigated RFA-induced cellular changes in the liver of pigs. MATERIAL AND METHODS: Healthy pigs (n=18) were sacrificed between day 0 and 3 months after RFA. The wound healing process was evaluated by computed tomography (CT), chromotrope anilinblue (CAB) staining of large-scale and standard tissue sections. Immunohistochemistry (IHC) for heat shock protein 70, Caspase-3, Ki67, Reelin, Vinculin, Vimentin and α-SMA was perfomed. RESULTS: One day after RFA, CAB staining showed cell damage and massive hyperaemia. All IHC markers were predominantly expressed at the outer borders of the lesion, except Reelin, which was mainly detected in untreated liver regions. By staining for Hsp70, the heat stress during RFA was monitored, which was most distinct 1-2 days after RFA. CT revealed decreased lesion size after one week. Development of a Vimentin and α-SMA positive fibrotic capsule was observed. CONCLUSION: In the early phase signs of cell damage, apoptosis and proliferation are dominant. Reduced expression of Reelin suggests a minor role of hepatic stellate cells in the RFA zone. After one week myofibroblasts become prominent and contribute to the development of the fibrotic capsule. This elucidates the pathophysiology of RFA and could contribute to the future optimization of RFA procedures.

Early remodeling of perinuclear Ca2+ stores and nucleoplasmic Ca2+ signaling during the development of hypertrophy and heart failure.

BACKGROUND: A hallmark of heart failure is impaired cytoplasmic Ca(2+) handling of cardiomyocytes. It remains unknown whether specific alterations in nuclear Ca(2+) handling via altered excitation-transcription coupling contribute to the development and progression of heart failure. METHODS AND RESULTS: Using tissue and isolated cardiomyocytes from nonfailing and failing human hearts, as well as mouse and rabbit models of hypertrophy and heart failure, we provide compelling evidence for structural and functional changes of the nuclear envelope and nuclear Ca(2+) handling in cardiomyocytes as remodeling progresses. Increased nuclear size and less frequent intrusions of the nuclear envelope into the nuclear lumen indicated altered nuclear structure that could have functional consequences. In the (peri)nuclear compartment, there was also reduced expression of Ca(2+) pumps and ryanodine receptors, increased expression of inositol-1,4,5-trisphosphate receptors, and differential orientation among these Ca(2+) transporters. These changes were associated with altered nucleoplasmic Ca(2+) handling in cardiomyocytes from hypertrophied and failing hearts, reflected as increased diastolic Ca(2+) levels with diminished and prolonged nuclear Ca(2+) transients and slowed intranuclear Ca(2+) diffusion. Altered nucleoplasmic Ca(2+) levels were translated to higher activation of nuclear Ca(2+)/calmodulin-dependent protein kinase II and nuclear export of histone deacetylases. Importantly, the nuclear Ca(2+) alterations occurred early during hypertrophy and preceded the cytoplasmic Ca(2+) changes that are typical of heart failure. CONCLUSIONS: During cardiac remodeling, early changes of cardiomyocyte nuclei cause altered nuclear Ca(2+) signaling implicated in hypertrophic gene program activation. Normalization of nuclear Ca(2+) regulation may therefore be a novel therapeutic approach to prevent adverse cardiac remodeling.

Bronchoalveolar lavage lateral-flow device test for invasive pulmonary aspergillosis in solid organ transplant patients: a semiprospective multicenter study.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) remains an important cause of morbidity and mortality among patients undergoing solid organ transplantation (SOT). Because of the crude mortality of 80% to 90% in the absence of adequate treatment, timely diagnosis and early intervention with antifungal drugs are key factors in the successful treatment of IPA. Diagnosis, however, remains difficult. Therefore, new diagnostic tests are urgently needed. The Lateral-Flow Device (LFD) test is a rapid (15 min) single-sample point-of-care test that is based on the detection of an Aspergillus extracellular glycoprotein antigen by monoclonal antibody JF5. METHODS: This semiprospective multicenter study evaluated the LFD test for IPA diagnosis (established by galactomannan and culture results) by using bronchoalveolar lavage (BAL) samples from patients after SOT. Participating centers were the three Austrian Medical Universities of Innsbruck, Vienna, and Graz. RESULTS: Forty-seven BAL samples from 47 SOT patients were included (26 patients had undergone lung transplantation, 13 liver, 6 kidney, and 2 heart transplantation; 11 probable or proven IPA, 11 possible IPA, 25 no IPA) at the three Austrian Medical Universities of Innsbruck, Vienna, and Graz. Sensitivity and specificity, positive and negative predictive values, as well as diagnostic odds ratio of BAL LFD tests for probable IPA were 91%, 83%, 63%, 97%, and 50% (95% confidence interval, 5.4%-467%), respectively. CONCLUSION: To conclude, the LFD test of BAL specimens is performed easily and provides accurate and rapidly available results in patients after SOT. Therefore, this new point-of-care test may be a promising diagnostic approach for detecting IPA using BAL specimens from SOT patients.

Docosahexaenoic acid (DHA)-induced heme oxygenase-1 attenuates cytotoxic effects of DHA in vascular smooth muscle cells.

OBJECTIVE: Docosahexaenoic acid (DHA), a member of n-3 polyunsaturated fatty acids (n-3 PUFA) is a potent regulator of molecular events implicated in cardiovascular health. In a previous study we found that Ca(2+)-dependent oxidative stress is the central and initial event responsible for induction of unfolded protein response (UPR), cell cycle arrest and apoptosis in DHA treated primary human smooth muscle cells isolated from small pulmonary artery (hPASMC). In the present study we examined the impact of heme oxygenase (HO)-1, induced by DHA, on DHA-induced oxidative stress, UPR, cell proliferation and apoptosis in hPASMC. METHODS & RESULTS: DHA led to a time- and concentration-dependent increase in HO-1 mRNA and protein levels in hPASMC. The DHA-induced HO-1 upregulation could be attenuated by preincubation of cells with a strong antioxidant Tempol or by siRNA-mediated depletion of nuclear factor erythroid 2-related factor-2 (Nrf2). In DHA-treated hPASMC, depletion of HO-1 by siRNA-mediated silencing resulted in increased levels of reactive oxygen species (ROS) and increased duration of UPR, the latter revealed by monitoring of spliced X-box binding protein 1 (XBP-1) variant. Moreover, HO-1 silencing augmented apoptosis in DHA-treated hPASMC as found by increased numbers of cleaved caspase-3-positive cells. HO-1 silencing did not affect proliferation of hPASMC exposed to DHA. CONCLUSION: Our results indicate that DHA-induced, ROS-dependent upregulation of HO-1 attenuates oxidative stress, UPR and apoptosis in DHA-treated hPASMC.

Oxidative stress and apoptosis in a pig model of brain death (BD) and living donation (LD).

BACKGROUND: As organ shortage is increasing, the acceptance of marginal donors increases, which might result in poor organ function and patient survival. Mostly, organ damage is caused during brain death (BD), cold ischemic time (CIT) or after reperfusion due to oxidative stress or the induction of apoptosis. The aim of this study was to study a panel of genes involved in oxidative stress and apoptosis and compare these findings with immunohistochemistry from a BD and living donation (LD) pig model and after cold ischemia time (CIT). METHODS: BD was induced in pigs; after 12 h organ retrieval was performed; heart, liver and kidney tissue specimens were collected in the BD (n = 6) and in a LD model (n = 6). PCR analysis for NFKB1, GSS, SOD2, PPAR-alpha, OXSR1, BAX, BCL2L1, and HSP 70.2 was performed and immunohistochemistry used to show apoptosis and nitrosative stress induced cell damage. RESULTS: In heart tissue of BD BAX, BCL2L1 and HSP 70.2 increased significantly after CIT. Only SOD2 was over-expressed after CIT in BD liver tissue. In kidney tissue, BCL2L1, NFKB, OXSR1, SOD2 and HSP 70.2 expression was significantly elevated in LD. Immunohistochemistry showed a significant increase in activated Caspase 3 and nitrotyrosine positive cells after CIT in BD in liver and in kidney tissue but not in heart tissue. CONCLUSION: The up-regulation of protective and apoptotic genes seems to be divergent in the different organs in the BD and LD setting; however, immunohistochemistry revealed more apoptotic and nitrotyrosine positive cells in the BD setting in liver and kidney tissue whereas in heart tissue both BD and LD showed an increase.

Knowledge and attitude of ICU nurses, students and patients towards the Austrian organ donation law.

BACKGROUND: A survey on the knowledge and attitudes towards the Austrian organ donation legislation (an opt-out solution) of selected groups of the Austrian population taking into account factors such as age, gender, level of education, affiliation to healthcare professions and health related studies was conducted. METHODS: An online survey among 3 target groups (ICU nurses, health science students and non health science students) was performed and results were compared to the answers from transplantation patients to a paper questionnaire. A total of 8415 persons were asked to participate in the survey and 2025 (24%) persons correctly completed the questionnaire. 1945 online responses (ICU nurses n = 185; students of health sciences n = 1277; students of non-health science related courses n = 483) were analysed and data were compared to 80 manually filled-in responses from patients from a previous study. RESULTS: 84% of participants state that they know the Austrian organ donation legislation; this percentage varies significantly (p < 0.05) within the target groups and is influenced by demographic variables of the participants. 74% think that the law is good and 79% do not favour a change. Opinions and attitudes towards the legal situation are positively influenced by the affiliation to healthcare professions and health-related fields of study. Interviewed persons who were aware of the legislation before the survey had a more positive attitude towards the existing legislation (77% versus 74%, p < 0.05). CONCLUSIONS: The information level on Austrian organ donation legislation is high. ICU nurses and those who did not know the law before were most critical towards the existing legislation. Therefore education to increase knowledge in the general population and goal-oriented efforts to increase awareness in the target groups should be emphasized.

Complication profile of the Berlin Heart EXCOR biventricular support in children.

In chronic cardiomyopathy, mechanical circulatory support (MCS) plays an increasingly important role for children as the shortage of suitable donor hearts increases waiting time on the transplant list. We report our experience with the paracorporal Berlin Heart EXCOR System (Berlin Heart AG, Berlin, Germany) used as a biventricuclar assist device (BVAD). Nine patients with a BVAD EXCOR system were treated between 2006 and 2012; out of these patients, four were less than 18 years old (6, 14, 14, and 17 years old). Their diagnoses were postcardotomy failure (n = 1), dilatative cardiomyopathy (n = 2), and terminal heart failure (n = 1). Overall survival, waiting time for heart transplantation (HTx) and complication profile for the BVAD were analyzed retrospectively. Thirty days' mortality was 25% (n = 1). One child died after 84 days on support due to cerebral bleeding. Mean support time was 218.75 days (4, 84, 262, and 525 days). Pump chamber exchange was necessary three times due to pump chamber thrombosis (n = 2) and partial pump chamber membrane rupture (n = 1). Complications included: sepsis (n = 1), drive line infection requiring intravenous antibiotics (n = 2), and recurrent epistaxis (n = 3). Two children were successfully transplanted after 262/525 days on BVAD; they are currently at home (follow-up: 1.9 and 2.3 years). The EXCOR is a life-saving MCS system suitable for long-term paracorporeal biventricular assistance.

Energy status of pig donor organs after ischemia is independent of donor type.

BACKGROUND: Literature is controversial whether organs from living donors have a better graft function than brain dead (BD) and non-heart-beating donor organs. Success of transplantation has been correlated with high-energy phosphate (HEP) contents of the graft. METHODS: HEP contents in heart, liver, kidney, and pancreas from living, BD, and donation after cardiac death in a pig model (n=6 per donor type) were evaluated systematically. BD was induced under general anesthesia by inflating a balloon in the epidural space. Ten hours after confirmation, organs were retrieved. Cardiac arrest was induced by 9V direct current. After 10min of ventricular fibrillation without cardiac output, mechanical and medical reanimation was performed for 30min before organ retrieval. In living donors, organs were explanted immediately. Freeze-clamped biopsies were taken before perfusion with Celsior solution (heart) or University of Wisconsin solution (abdominal organs) in BD and living donors or with Histidine-Tryptophan-Ketoglutaric solution (all organs) in non-heart-beating donors, after perfusion, and after cold ischemia (4h for heart, 6h for liver and pancreas, and 12h for kidney). HEPs (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and phosphocreatine), xanthine, and hypoxanthine were measured by high-performance liquid chromatography. Energy charge and adenosine triphosphate-to-adenosine diphosphate ratio were calculated. RESULTS: After ischemia, organs from different donor types showed no difference in energy status. In all organs, a decrease of HEP and an increase in hypoxanthine contents were observed during perfusion and ischemia, irrespective of the donor type. CONCLUSION: Organs from BD or non-heart-beating donors do not differ from living donor organs in their energy status after average tolerable ischemia.

Effect of oxidative stress and endotoxin on human serum albumin in brain-dead organ donors.

Albumin, among other molecules, binds and detoxifies endotoxin in healthy people. Oxidative stress leads to protein oxidation and thus to the impaired binding properties of albumin. This property, in combination with increased gut permeability, leads to the appearance of endotoxin in the systemic circulation and to impaired organ function. We hypothesize that these processes occur in the serum of brain-dead organ donors. Endotoxin was determined with an adapted Limulus amoebocyte lysate assay. The albumin fractions and binding capacity were determined by high-performance liquid chromatography (HPLC). FlowCytomix (eBioscience, San Diego, Calif) was used to determine the cytokine levels. Carbonylated proteins (CPs) and myeloperoxidase (MPO) were measured by an enzyme-linked immunosorbent assay (ELISA). Eighty-four brain-dead organ donors were enrolled and categorized by the duration of intensive care unit (ICU) stay. The albumin-binding capacity for dansylsarcosine was reduced in brain-dead patients compared with controls. Endotoxin positivity in 16.7% of donors was associated with decreased binding capacity in donors and worse survival of recipients. The CP and MPO levels of organ donors were significantly higher than in healthy controls. The durations of ICU stay increased albumin oxidation. In addition, interleukin-6 (IL-6), IL-8, IL-10, and IL-1ß levels were increased in patients, whereas the interferon-γ (IFN-γ) levels were within the normal range. We conclude that oxidative stress and systemic endotoxemia are present in brain-dead organ donors, which might affect recipient survival. High endotoxin levels might be caused by increased gut permeability and decreased binding capacity of albumin influenced not just by higher albumin oxidation.

Everolimus in different combinations as maintenance immunosuppressive therapy in heart transplant recipients.

OBJECTIVES: We examined the experiences of heart transplant recipients receiving everolimus as maintenance therapy in different combinations over a long time. MATERIALS AND METHODS: Between 2004 and 2009, forty patients (29 men, 11 women; mean age, 51.6 y) were switched from a routine immunosuppressive regimen to everolimus. Indications were other (2), renal insufficiency (17), cardiac allograft vasculopathy (14), and ongoing cellular rejection (7). Combinations were either along with cyclosporine (24), mycophenolate mofetil (14), or others (2). Indications for the introduction of everolimus including safety, efficacy, different combinations of everolimus, biopsy-proven acute rejections, renal function, and infections were evaluated retrospectively. RESULTS: Five patients died, 4 of them were still on everolimus at the time of death; they died from intracerebral hemorrhage (1), embolism (1), cardiac arrest (2), and unknown (1). Everolimus was discontinued in 6 patients owing to severe adverse effects: Edema (2), gastrointestinal adverse effects (3), and dermal adverse effects (1). Mean everolimus trough levels were 5.8 µmol/L at 6 months and 4.9 at 60 months. Mean cyclosporine levels were 67.62 µmol/L at 6 months and 47.3 µmol/L at 60 months. Mean serum creatinine levels were stable (147.9 µmol/L after 60 months). Four life-threatening infections (all pneumonia) occurred but resulted in complete recovery. CONCLUSIONS: Everolimus is safe with different immunosuppressive combinations after receiving a heart transplant.

A 10min "no-touch" time - is it enough in DCD? A DCD animal study.

Donation after cardiac death (DCD) is under investigation because of the lack of human donor organs. Required times of cardiac arrest vary between 75s and 27min until the declaration of the patients' death worldwide. The aim of this study was to investigate brain death in pigs after different times of cardiac arrest with subsequent cardiopulmonary resuscitation (CPR) as a DCD paradigm. DCD was simulated in 20 pigs after direct electrical induction of ventricular fibrillation. The "no-touch" time varied from 2min up to 10min; then 30min of CPR were performed. Brain death was determined by established clinical and electrophysiological criteria. In all animals with cardiac arrest of at least 6min, a persistent loss of brainstem reflexes and no reappearance of bioelectric brain activity occurred. Reappearance of EEG activity was found until 4.5min of cardiac arrest and subsequent CPR. Brainstem reflexes were detectable until 5min of cardiac arrest and subsequent CPR. According to our experiments, the suggestion of 10min of cardiac arrest being equivalent to brain death exceeds the minimum time after which clinical and electrophysiological criteria of brain death are fulfilled. Therefore shorter "no-touch" times might be ethically acceptable to reduce warm ischemia time.

Myeloperoxidase and carbonyl proteins: promising markers for non-invasive monitoring of graft rejection after heart transplantation.

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 µg/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.