"Seeing inside out": revealing the effectiveness of otoscopy training in virtual reality enhanced practical exams - a randomized controlled trial.

BACKGROUND: The study aimed to assess the impact of different training modalities on otoscopy performance during a practical exam using a high-fidelity simulator and to determine if objective evaluation of otoscopy is feasible using a simulator that records insertion depth and tympanic membrane coverage. METHODS: Participants were assigned to one of four groups: control and three intervention groups with varying training approaches. Participants received otoscopy training and then were assessed through a practical exam on a high-fidelity simulator that uses virtual reality to visualize the ear canal and middle ear. Performance was evaluated using a modified Objective Structured Assessment of Technical Skills checklist and Integrated Procedural Performance Instrument checklist. Insertion depth, tympanic membrane coverage, and correct diagnosis were recorded. Data were tested for normal distribution using the Shapiro-Wilk test. One-way ANOVA and, for non-normally distributed data, Kruskal-Wallis test combined with Dunn's test for multiple comparisons were used. Interrater reliability was assessed using Cohen's κ and Intraclass correlation coefficient. RESULTS: All groups rated their training sessions positively. Performance on the OSATS checklist was similar among groups. IPPI scores indicated comparable patient handling skills. The feedback group examined larger tympanic membrane areas and had higher rates of correct diagnosis. The correct insertion depth was rarely achieved by all participants. Interrater reliability for OSATS was strong. IPPI reliability showed good correlation. CONCLUSION: Regardless of training modality, participants perceived learning improvement and skill acquisition. Feedback improved examination performance, indicating simulator-guided training enhances skills. High-fidelity simulator usage in exams provides an objective assessment of performance.

Learning surgical knot tying and suturing technique - effects of different forms of training in a controlled randomized trial with dental students.

Objective: The acquisition of surgical skills requires motor learning. A special form of this is intermanual transfer by transferring motor skills from the nondominant hand (NDH) to the dominant hand (DH). The purpose of this study was to determine the learning gains that can be achieved for the DH by training with the DH, the NDH, and by non-surgical alternative training (AT). Methods: 124 preclinical (n=62) and clinical (n=62) dental students completed surgical knot tying and suturing technique training with the DH, with the NDH, and an AT in a controlled randomized trial. Results: A statistically significant learning gain in knot tying and suture technique with the DH was evident only after training with the DH when compared to training with the NDH (p<0.001 and p=0.004, respectively) and an AT (p=0.001 and p=0.010, respectively). Of those students who achieved a learning gain ≥4 OSATS points, 46.4% (n=32) benefited in their knot tying technique with the DH from training with the DH, 29.0% (n=20) from training with the NDH, and 24.6% (n=17) from an AT while 45.7% (n=32) benefited in their suturing technique with the DH from training with the DH, 31.4% (n=22) from training with the NDH, and 22, 9% (n=16) from an AT. Conclusions: Training with the DH enabled significantly better learning gains in the surgical knot tying and suturing techniques with the DH.

[Quality management in a postgraduate refresher course in otolaryngology]. / Qualitätssicherungssystem zur Bewertung eines HNO-Facharztrepetitoriums.

BACKGROUND: Residency training is often characterized by locally influenced training content and focus, which can lead to heterogeneous training outcomes. Refresher courses before the speciality certificate examinations can harmonize the situation. OBJECTIVE: The current publication aims to present a quality management system for evaluation of a postgraduate refresher course for otolaryngology residents. MATERIALS AND METHODS: The teaching sessions of a postgraduate course were evaluated using questionnaires. Descriptive statistics and multivariable binary logistic regression analysis were performed. To evaluate the factors leading to a negative perception of a teaching session, the focus was set on the worst 15% of all total ratings. An exemplary strength/weakness profile of a lecturer was created for individual feedback. RESULTS: Analysis of the evaluation results showed an overall average rating of 12.8 (±2.4) out of a maximum of 15 possible points. Multivariable regression determined the items "friendliness," "systematic structure," "own involvement," "prior knowledge," and "efficient teaching session" to be significant for a negative perception of a teaching session. Using the lecturer profile, the strengths and weaknesses of the individual lecturer can be shown in an objective manner. CONCLUSION: The developed questionnaire represents a good tool for quality management of a postgraduate refresher course for otolaryngology residents. This is achieved by regression analysis and creation of an individual lecturer profile, which provides an objective basis for improving the individual teaching session through detailed feedback to the lecturer.

Transcriptome Profiling Identifies TIGIT as a Marker of T-Cell Exhaustion in Liver Cancer.

BACKGROUND AND AIMS: Programmed death 1 (PD-1) checkpoint inhibition has shown promising results in patients with hepatocellular carcinoma, inducing objective responses in approximately 20% of treated patients. The roles of other coinhibitory molecules and their individual contributions to T-cell dysfunction in liver cancer, however, remain largely elusive. APPROACH AND RESULTS: We performed a comprehensive mRNA profiling of cluster of differentiation 8 (CD8) T cells in a murine model of autochthonous liver cancer by comparing the transcriptome of naive, functional effector, and exhausted, tumor-specific CD8 T cells. Subsequently, we functionally validated the role of identified genes in T-cell exhaustion. Our results reveal a unique transcriptome signature of exhausted T cells and demonstrate that up-regulation of the inhibitory immune receptor T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitor motif domains (TIGIT) represents a hallmark in the process of T-cell exhaustion in liver cancer. Compared to PD-1, expression of TIGIT more reliably identified exhausted CD8 T cells at different stages of their differentiation. In combination with PD-1 inhibition, targeting of TIGIT with antagonistic antibodies resulted in synergistic inhibition of liver cancer growth in immunocompetent mice. Finally, we demonstrate expression of TIGIT on tumor-infiltrating CD8 T cells in tissue samples of patients with hepatocellular carcinoma and intrahepatic cholangiocarcinoma and identify two subsets of patients based on differential expression of TIGIT on tumor-specific T cells. CONCLUSIONS: Our transcriptome analysis provides a valuable resource for the identification of key pathways involved in T-cell exhaustion in patients with liver cancer and identifies TIGIT as a potential target in checkpoint combination therapies.

Regression analyses of questionnaires in bedside teaching.

BACKGROUND: Students' ratings of bedside teaching courses are difficult to evaluate and to comprehend. Validated systematic analyses of influences on students' perception and valuation of bedside teaching can serve as the basis for targeted improvements. METHODS: Six hundred seventy-two observations were conducted in different surgical departments. Survey items covered the categories teacher's performance, student's self-perception and organizational structures. Relevant factors for the student overall rating were identified by multivariable linear regression after exclusion of variable correlations > 0.500. The main target for intervention was identified by the 15% worst overall ratings via multivariable logistic regression. RESULTS: According to the students the success of bedside teaching depended on their active participation and the teacher's explanations of pathophysiology. Further items are both relevant to the overall rating and a possible negative perception of the session. In comparison, negative perception of courses (worst 15%) is influenced by fewer variables than overall rating. Variables that appear in both calculations show slight differences in their weighing for their respective endpoints. CONCLUSION: Relevant factors for overall rating and negative perception in bedside teaching can be identified by regression analyses of survey data. Analyses provide the basis for targeted improvement.

Expression of human thrombomodulin on porcine endothelial cells can reduce platelet aggregation but did not reduce activation of complement or endothelium - an experimental study.

Clinical xenotransplantation will only be feasible when present limitations can be controlled sufficiently. Activation of endothelium and complement as well as coagulopathy and thrombotic microangiopathy (TMA) is important barriers. Transgenic expression of hTBM on porcine endothelial cells is a reasonable approach to reduce activation of haemostasis. Endothelial cells from wild-type pigs as well from pigs expressing hTBM alone or in combination with hCD46 and knockout of the alpha-1,3,-galactosyltransferase (GTKO) were perfused with platelet-rich plasma in a microfluidic flow chamber. Platelet aggregation and activation, coagulation, complement and endothelial cell activation were assessed. Perfusion of wild-type porcine aortic endothelial cells (PAEC) resulted in distinct platelet aggregation. Expression of hTBM in either mono-transgenic or triple-transgenic (GTKO/hCD46/hTBM) PAEC showed significantly reduced or absent platelet aggregation. Flow cytometric analysis of platelets showed an increased CD62P expression in wild-type PAEC and significantly reduced expression in mono- or triple-transgenic PAEC. Activation of coagulation measured by TAT occured in WT PAEC and was clearly reduced in hTBM and GTKO/hCD46/hTBM PAEC. Activation of complement and endothelial cells was only reduced in GTKO/hCD46/hTBM but not in PAEC expressing hTBM alone. Expression of hTBM was able to prevent activation of coagulation and platelet aggregation in mono- and triple-transgenic PAEC, while activation of complement and endothelial cells was not reduced in mono-transgenic PAEC.

Investigation of the influence of xenoreactive antibodies on activation of complement and coagulation in an ex vivo perfusion animal study using porcine kidneys.

During pig-to-primate xenotransplantation or perfusion of porcine organs with human blood, a xenogeneic coagulopathy with consecutive development of thrombotic microangiopathy (TMA) can be observed. The aim of this study was to elucidate the influence of the reduction of xenoreactive natural antibodies on the coagulopathy using an ex vivo perfusion system. Thirteen perfusion experiments using landrace wild-type porcine kidneys were performed in three different experimental groups: autologous, xenogeneic, and immunoadsorption. During and after perfusion, blood and tissue samples were collected to assess markers of coagulation, complement, inflammation, and endothelial activation. Immunoadsorption prior to perfusion did not prolong perfusion time (174 min ±28) compared to xenogeneic (182 min ±22) experiments, whereas autologous perfusion was possible for maximum of 240 min in all experiments. Activation of coagulation was similar comparing perfusions after immunoadsorption (D-Dimer 24 186 µg/l ±5813; TAT 566 µg/l ±34) to xenogeneic (D-Dimer 22 175 µg/l ±7826, TAT 600 µg/l ±0) experiments. But antibody-mediated complement activation was reduced in the immunoadsorption group. TNF-alpha and markers of endothelial cell activation were lower in the immunoadsorption group compared to the xenogeneic experiments. In this ex vivo perfusion model, we observed that marked removal of xenogeneic antibodies can reduce complement activation via the classical pathway as well as endothelial cell activation and inflammation. Immunoadsorption cannot prevent the activation of the terminal complement cascade and coagulation.

Hepatocyte-induced CD4+ T cell alloresponse is associated with major histocompatibility complex class II up-regulation on hepatocytes and suppressible by regulatory T cells.

Hepatocyte transplantation is a promising therapeutic approach for various liver diseases. Despite the liver's tolerogenic potential, early immune-mediated loss of transplanted cells is observed, and longterm acceptance has not been achieved yet. Patients deemed tolerant after liver transplantation presented an increased frequency of regulatory T cells (Tregs), which therefore also might enable reduction of posttransplant cell loss and enhance longterm allograft acceptance. We hence characterized hepatocyte-induced immune reactions and evaluated the immunomodulatory potential of Tregs applying mixed lymphocyte cultures and mixed lymphocyte hepatocyte cultures. These were set up using peripheral blood mononuclear cells and primary human hepatocytes, respectively. Polyclonally expanded CD4+ CD25high CD127low Tregs were added to cocultures in single-/trans-well setups with/without supplementation of anti-interferon γ (IFNγ) antibodies. Hepatocyte-induced alloresponses were then analyzed by multicolor flow cytometry. Measurements indicated that T cell response upon stimulation was associated with IFNγ-induced major histocompatibility complex (MHC) class II up-regulation on hepatocytes and mediated by CD4+ T cells. An indirect route of antigen presentation could be ruled out by use of fragmented hepatocytes and culture supernatants of hepatocytes. Allospecific proliferation was accompanied by inflammatory cytokine secretion. CD8+ T cells showed early up-regulation of CD69 despite lack of cell proliferation in the course of coculture. Supplementation of Tregs effectively abrogated hepatocyte-induced alloresponses and was primarily cell contact dependent. In conclusion, human hepatocytes induce a CD4+ T cell alloresponse in vitro, which is associated with MHC class II up-regulation on hepatocytes and is susceptible to suppression by Tregs. Liver Transplantation 24 407-419 2018 AASLD.

Risk-factors for nodular hyperplasia of parathyroid glands in sHPT patients.

INTRODUCTION: Nodular hyperplasia of parathyroid glands (PG) is the most probable cause of medical treatment failure in secondary hyperparathyroidism (sHPT). This prospective cohort study is located at the interface of medical and surgical consideration of sHPT treatment options and identifies risk-factors for nodular hyperplasia of PG. MATERIAL AND METHODS: One-hundred-eight resected PG of 27 patients with a broad spectrum of sHPT severity were classified according to the degree of hyperplasia by histopathology. Twenty routinely gathered parameters from medical history, ultrasound findings of PG and laboratory results were analyzed for their influence on nodular hyperplasia of PG by risk-adjusted multivariable binary regression. A prognostic model for non-invasive assessment of PG was developed and used to weight the individual impact of identified risk-factors on the probability of nodular hyperplasia of single PG. RESULTS: Independent risk-factors for nodular hyperplasia of single PG were duration of dialysis in years, PG volume in mm3 determined by ultrasound and serum level of parathyroid hormone in pg/mL. Multivariable analyses computed a model with an Area Under the Receiver Operative Curve of 0.857 (95%-CI:0.773-0.941) when predicting nodular hyperplasia of PG. Theoretical assessment of risk-factor interaction revealed that the duration of dialysis had the strongest influence on the probability of nodular hyperplasia of single PG. CONCLUSIONS: The three identified risk-factors (duration of dialysis, PG volume determined by ultrasound and serum level of parathyroid hormone) can be easily gathered in daily routine and could be used to non-invasively assess the probability of nodular hyperplasia of PG. This assessment would benefit from periodically collected data sets of PG changes during the course of sHPT, so that the choice of medical or surgical sHPT treatment could be adjusted more to the naturally changing type of histological PG lesion on an individually adopted basis in the future.

Identification of the resection severity index as a significant independent prognostic factor for early mortality and observed survival >5 and >10 years after liver resection for hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: This study evaluates predictive factors for observed long-term survival of more than 5 and 10 years for patients after liver resection for hepatocellular carcinoma and compares their life expectancy to the normal national population matched for sex, year of birth and age at resection. METHODS: 230 patients after primary liver resection for HCC (01.01.1995-31.12.2004) were analyzed. Multivariable logistic regression models were determined based on Cox regression results and their prognostic capability evaluated with areas under the receiver operating characteristic curve (AUROCs). RESULTS: Life years after surgery in deceased patients compared to the normal national population matched for sex, year of birth and age at resection was reduced by median 21.7 years. Independent predictive factors for 10-year survival were age at resection (p < 0.001; OR = 0.898; 95%-CI: 0.846-0.954), UICC 7 tumor staging (p = 0.003; OR = 0.344; 95%-CI: 0.126-0.941) and ASAT (GOT) in U/l divided by Quick in percent multiplied by the extent of liver resection graded in points labelled as the resection severity index (p < 0.001; OR = 0.136; 95%-CI: 0.022-0.843) enabling prediction of 10-year survival with an AUROC of 0.884. The same factors plus revision surgery (yes/no) predict 5-year survival (AUROC 0.736). CONCLUSIONS: Liver resection enables predictable long-term survival >5 and > 10 years. The proposed resection severity index quantifies the prognostic relevance of liver cellular damage, synthesis and loss of parenchyma for long-term survival.

Short- and long-term effects of the use of RAAS blockers immediately after renal transplantation.

BACKGROUND: The efficacy and safety of renin angiotensin aldosterone system blockers (RAASB's) if introduced immediately after renal transplantation have not been extensively investigated. METHODS: The medical charts of 142 kidney transplant recipients who received a RAASB in the early postoperative period and of 114 matched controls were analyzed. The RAASB was given primarily for blood pressure control. RESULTS: 117 patients continued to receive and 50 controls remained continuously free of the RAASB in the first year. The RAASB was added on average at postoperative day 8 and the mean duration of follow-up was 5.4 years. Systolic, blood pressure at treatment initiation was increased in the RAASB group (150 ± 17 vs. 141 ± 16, p < 0.001). At discharge from hospital and during follow-up blood pressure was similar in both groups, without differences in GFR, potassium and proteinuria. The endpoints "graft failure" and "graft failure or death from any cause" were significantly better in patients treated with RAASB's (p = 0.03 and p = 0.04, respectively). The treatment effects in the RAASB group persisted even after adjustment for demographic parameters, immunological risk factors, peritransplant risk factors, duration of dialysis prior to transplantation and medical comorbidities. CONCLUSIONS: Thus, RAASB's can be used effectively and safely to treat hypertension in the early postoperative period after kidney transplantation and are renoprotective in the long term.

Monitoring of liver function in a 73-year old patient undergoing 'Associating Liver Partition and Portal vein ligation for Staged hepatectomy': case report applying the novel liver maximum function capacity test.

BACKGROUND: The two-stage liver resection combining in situ liver transection with portal vein ligation, also referred to as ALPPS (Associating Liver Partition and Portal vein ligation for Staged hepatectomy), has been described as a promising method to increase the resectability of liver tumors. However, one of the most important issues regarding the safety of this procedure is the optimal timing of the second stage at the point of sufficient hypertrophy of the future liver remnant. The recently developed liver maximum function capacity test (LiMAx) can be applied to monitor the liver function postoperatively and hence could be a useful tool for decision-making regarding the timing of the second stage of ALPPS. CASE PRESENTATION: A 73-year-old female patient presented with metachronous colorectal liver metastasis comprising the complete right liver lobe as well as segment IV. Due to an insufficient future liver remnant (19.3 %; segments II and III of the liver) and a low future liver remnant:body weight ratio (0.28 %) the decision was made to perform an ALPPS-procedure in order to avoid development of postoperative small-for-size syndrome. Despite a formally sufficient increase of the FLR to 30.8 % within 7 days after the first step of ALPPS, the liver function was seen to only slowly increase as expressed by a LiMAx value of 245 µg/h/kg (baseline of 282 µg/h/kg prior to surgery). By means of the LiMAx test, sufficient increase of liver function eventually was detected by postoperative day 11 (LiMAx value of 371 µg/h/kg; FLR 35.2 %) so that the second step of ALPPS (completion of hepatectomy) was performed with no signs of liver failure during further clinical course. CONCLUSION: Performing ALPPS we have observed a significant difference between the increase in future liver remnant volume and function applying the LiMAx test. The latter tool thus might proof valuable for application in two-stage liver resection to avoid postoperative small-for-size syndrome.

A Depleting Anti-CD45 Monoclonal Antibody as Isolated Conditioning for Bone Marrow Transplantation in the Rat.

OBJECTIVE: A monoclonal antibody (mAb) against the leukocyte common antigen CD45 (RT7 in rats) could facilitate bone marrow transplantation (BMT). This study in rats evaluates a depletive rat anti-RT7a mAb as isolated tool for BMT conditioning without using irradiation or any chemotherapeutic / immunosuppressive agent. METHODS: The model used a CD45 di-allelic polymorphism (RT7a/RT7b). The anti-RT7a mAb was intravenously administered to LEW.1W rats (RT1uRT7a) at 5, 10 and 15 mg/kg. 1x10(8) BM cells of MHC syngeneic (RT1u), MHC disparate (RT1l) or MHC haploidentical (RT1u/l) donors were transplanted. All BM donor strains carried the RT7b allele so that their CD45+ cells were not affected by the anti-RT7a mAb. Recipients were monitored for reconstitution and donor-chimerism in blood leukocytes. RESULTS: mAb dosages of 5 or 10 mg/kg were myelosuppressive, whereas 15 mg/kg was myeloablative. Multi-lineage donor-chimerism at day 100 indicated engraftment of MHC syngeneic BM after any used mAb dosage (5 mg/kg: 46+/-7%; 10 mg/kg: 62+/-5%; 15 mg/kg: 80+/-4%). MHC disparate BM resulted in autologous reconstitution after conditioning by 10 mg/kg of the mAb and caused transient chimerism ending up in death associated with aplasia after conditioning by 15 mg/kg of the mAb. MHC haploidentical BM (F1 to parental) engrafted only after conditioning by 15 mg/kg (chimerism at day 100: 78+/-7%). Abandonment of α/ß TCR+ cell depletion from BM grafts impaired the engraftment process after conditioning using 15 mg/kg of the mAb in the MHC syngeneic setting (2 of 6 recipients failed to engraft) and the MHC haploidentical setting (3 of 6 recipients failed). CONCLUSION: This depletive anti-RT7a mAb is myelosuppressive and conditions for engraftment of MHC syngeneic BM. The mAb also facilitates engraftment of MHC haploidentical BM, if a myeloablative dose is used. RT7b expressing, BM-seeded α/ß TCR+ cells seem to impair the engraftment process after myeloablative mAb conditioning.

Liver Transplantation for Hepatocellular Carcinoma: A Single Center Resume Overlooking Four Decades of Experience.

Background. This is a single center oncological resume overlooking four decades of experience with liver transplantation (LT) for hepatocellular carcinoma (HCC). Methods. All 319 LT for HCC that were performed between 1975 and 2011 were included. Predictors for HCC recurrence (HCCR) and survival were identified by Cox regression, Kaplan-Meier analysis, Log Rank, and χ (2)-tests where appropriate. Results. HCCR was the single strongest hazard for survival (exp⁡(B) = 10.156). Hazards for HCCR were tumor staging beyond the histologic MILAN (exp⁡(B) = 3.645), bilateral tumor spreading (exp⁡(B) = 14.505), tumor grading beyond G2 (exp⁡(B) = 8.668), and vascular infiltration of small or large vessels (exp⁡(B) = 11.612, exp⁡(B) = 18.324, resp.). Grading beyond G2 (exp⁡(B) = 10.498) as well as small and large vascular infiltrations (exp⁡(B) = 13.337, exp⁡(B) = 16.737, resp.) was associated with higher hazard ratios for long-term survival as compared to liver transplantation beyond histological MILAN (exp⁡(B) = 4.533). Tumor dedifferentiation significantly correlated with vascular infiltration (χ (2) p = 0.006) and intrahepatic tumor spreading (χ (2) p = 0.016). Conclusion. LT enables survival from HCC. HCC dedifferentiation is associated with vascular infiltration and intrahepatic tumor spreading and is a strong hazard for HCCR and survival. Pretransplant tumor staging should include grading by biopsy, because grading is a reliable and easily accessible predictor of HCCR and survival. Detection of dedifferentiation should speed up the allocation process.

Inhibition of complement component C5 prevents clotting in an ex vivo model of xenogeneic activation of coagulation.

BACKGROUND: Xenogeneic thrombotic microangiopathy (TMA) and acute vascular rejection (AVR) prevent long-term survival of porcine xenografts after transplantation into non-human primates. Preformed xenoreactive natural antibodies (XNA) cause endothelial damage and activate the complement system. Mechanisms of xenogeneic coagulation and platelet activation are only poorly characterized. METHODS: A microfluidic flow chamber was used to study platelet activation and thrombus formation of human platelet-rich plasma (PRP) upon perfusion over wild-type (WT) or α-1,3- galactosyltransferase knockout (GTKO) and human CD46 (hCD46) transgenic porcine aortic endothelial cells (PAEC). Activation of plasma coagulation (thrombin-anti-thrombin complex; TAT) and complement (C3a, C5a) was studied in human platelet-free plasma (PFP) after co-incubation with PAEC. The activation of PAEC (E-Selectin, tissue factor, ICAM-1, ICAM-2, VCAM-1) was studied after incubation with human serum. Eculizumab (200 µg/ml) was used to inhibit terminal complement activation in all experiments. RESULTS: WT-PAEC perfused with human PRP showed thrombus formation at different shear rates (3 dyn/cm(2) : 23 ± 10%; 10 dyn/cm(2) : 17 ± 10% of flow chamber viewing field). GTKO/hCD46 PAEC exhibited reduced, but not fully prevented thrombus formation (3 dyn/cm(2) : 12 ± 12%). Porcine PRP caused little or no thrombus formation (3.0 ± 4% and 0.5 ± 0.9%, respectively). Flow cytometry of human platelets after perfusion over WT-PAEC revealed an increase in platelet CD62P expression (29.5 ± 3%), compared to non-perfused PRP (7 ± 2%) or PRP running through empty flow chambers (12.7 ± 0.3%). Incubation of human PFP with PAEC resulted in an increase of TAT that correlated with C5a activation. Specific inhibition of complement by eculizumab prevented thrombus formation (WT-PAEC: 1.6 ± 2% at 3 dyn/cm(2) and 0.24 ± 0.33% at 10 dyn/cm(2) , GTKO/hCD46 PAEC: 0.2 ± 0.3% at 3 dyn/cm(2) ) as well as activation of coagulation and platelets. Induction of endothelial E-Selectin and VCAM-1 in WT-PAEC upon incubation with human serum was significantly reduced by eculizumab. Eculizumab did not reduce thrombin generation capacity of human PRP or normal platelet aggregation. CONCLUSION: Thrombus formation in this ex vivo model of xenogeneic TMA was closely linked with complement activation. Specific inhibition of complement C5 by eculizumab prevented endothelial cell activation, but also coagulation and platelet activation without compromising thrombin generation capacity of human blood or normal platelet function.

Prediction of survival and tumor recurrence in patients undergoing surgery for pancreatic neuroendocrine neoplasms.

BACKGROUND: This study strives to define prognostic models for outcome after surgery for malignant pancreatic neuroendocrine tumors. METHODS: Forty-one patients were included. Prognostic models for mortality and disease recurrence were developed with multivariate binary logistic regression. RESULTS: The proposed prognostic model for tumor recurrence risk after surgery in percentage (AUROC = 0.774, 95%CI = 0.611-0.937) is: Risk in % = Exp(Y)/(1 + Exp(Y)), with Y = -4.360 + (0.015 × tumor diameter in cm) + (0.010 × preoperative platelet count in thousand/µl) + (1.077 × distant metastases, if yes = 1; if no = 0) + (-0.026 × Ki-67-positive cells in %) + (-1.086 × upper abdominal pain, if yes = 1; if no = 0). The proposed prognostic model for observed 3-year survival probability after surgery in % (AUROC = 0.932, 95%CI = 0.857-0.999) is: Survival probability in % = Exp(Y)/(1 + Exp(Y)), with Y = -12.492 + (0.054 × preoperative platelet count in thousand/µl) + (0.112 × minimal distance of the resection margin from the tumor in mm) + (-1.574 × number of positive lymph nodes) + (2.292 × histological tumor infiltration, if yes = 1; if no = 0) CONCLUSIONS: The platelet count was identified as a relevant risk factor. Proposed prognostic models with good model-fit display properties that indicate potential clinical usefulness.

Effect of TNF-alpha blockade on coagulopathy and endothelial cell activation in xenoperfused porcine kidneys.

BACKGROUND: Following pig-to-primate kidney transplantation, endothelial cell activation and xenogenic activation of the recipient's coagulation eventually leading to organ dysfunction and microthrombosis can be observed. In this study, we examined the effect of a TNF-receptor fusion protein (TNF-RFP) on endothelial cell activation and coagulopathy utilizing an appropriate ex vivo perfusion system. METHODS: Using an ex vivo perfusion circuit based on C1-Inhibitor (C1-Inh) and low-dose heparin administration, we have analyzed consumptive coagulopathy following contact of human blood with porcine endothelium. Porcine kidneys were recovered following in situ cold perfusion with Histidine-tryptophan-ketoglutarate (HTK) organ preservation solution and were immediately connected to a perfusion circuit utilizing freshly drawn pooled porcine or human AB blood. The experiments were performed in three individual groups: autologous perfusion (n = 5), xenogenic perfusion without any further pharmacological intervention (n = 10), or with addition of TNF-RFP (n = 5). After perfusion, tissue samples were obtained for real-time PCR and immunohistological analyses. Endothelial cell activation was assessed by measuring the expression levels of E-selectin, ICAM-1, and VCAM-1. RESULTS: Kidney survival during organ perfusion with human blood, C1-Inh, and heparin, but without any further pharmacological intervention was 126 ± 78 min. Coagulopathy was observed with significantly elevated concentrations of D-dimer and thrombin-antithrombin complex (TAT), resulting in the formation of multiple microthrombi. Endothelial cell activation was pronounced, as shown by increased expression of E-selectin and VCAM-1. In contrast, pharmacological intervention with TNF-RFP prolonged organ survival to 240 ± 0 min (max. perfusion time; no difference to autologous control). Formation of microthrombi was slightly reduced, although not significantly, if compared to the xenogenic control. D-dimer and TAT were elevated at similar levels to the xenogenic control experiments. In contrast, endothelial cell activation, as shown by real-time PCR, was significantly reduced in the TNF-RFP group. CONCLUSION: We conclude that although coagulopathy was not affected, TNF-RFP is able to suppress inflammation occurring after xenoperfusion in this ex vivo perfusion model.

Risk factors for short- and long-term mortality in liver transplant recipients with MELD score ≥30.

BACKGROUND: After introduction of MELD-based allocation in Germany, decreased waiting list mortality and increased mortality after transplantation have been reported. MATERIAL AND METHODS: This study compares relevant outcome parameters in patients with high MELD ≥30 versus lower MELD scores in a retrospective analysis including 454 consecutively performed liver transplantations in adults (age >16 years) at Hannover Medical School between 01/01/2007 and 31/12/2012 and a follow-up until 31/12/2013. Multivariable risk-adjusted models were applied to identify independent risk factors for 90-day and long-term mortality. RESULTS: MELD score ≥30 (n=117; 26.1%) was an independent risk factor for 90-day mortality (p=0.004, odds ratio: 3.045, 95% CI 1.439-6.498) and long-term mortality (p=0.016, hazard ratio: 1.620, 95% CI 1.095-2.396) and was associated with significantly longer hospital and intensive care unit stays (p<0.001), and death occurred in more cases earlier after transplantation (90-day mortality 21.6% vs. 13.0%; p=0.029). Portal vein thrombosis at transplantation was significantly associated with 90-day mortality after transplantation in patients with MELD scores ≥30 (p=0.041), but this was not the case for patients with MELD scores <30, although portal vein thrombosis was equally frequent in individuals of both groups (3.0% vs. 3.4%, p=0.824). CONCLUSIONS: Results of this study suggest that liver transplant recipients with portal vein thrombosis at transplantation should be transplanted before reaching a MELD score ≥30.

Kidneys From α1,3-Galactosyltransferase Knockout/Human Heme Oxygenase-1/Human A20 Transgenic Pigs Are Protected From Rejection During Ex Vivo Perfusion With Human Blood.

UNLABELLED: Multiple modifications of the porcine genome are required to prevent rejection after pig-to-primate xenotransplantation. Here, we produced pigs with a knockout of the α1,3-galactosyltransferase gene (GGTA1-KO) combined with transgenic expression of the human anti-apoptotic/anti-inflammatory molecules heme oxygenase-1 and A20, and investigated their xenoprotective properties. METHODS: The GGTA1-KO/human heme oxygenase-1 (hHO-1)/human A20 (hA20) transgenic pigs were produced in a stepwise approach using zinc finger nuclease vectors targeting the GGTA1 gene and a Sleeping Beauty vector coding for hA20. Two piglets were analyzed by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and sequencing. The biological function of the genetic modifications was tested in a (51)Chromium release assay and by ex vivo kidney perfusions with human blood. RESULTS: Disruption of the GGTA1 gene by deletion of few basepairs was demonstrated in GGTA1-KO/hHO-1/hA20 transgenic pigs. The hHO-1 and hA20 mRNA expression was confirmed by quantitative reverse-transcription polymerase chain reaction. Ex vivo perfusion of 2 transgenic kidneys was feasible for the maximum experimental time of 240 minutes without symptoms of rejection. CONCLUSIONS: Results indicate that GGTA1-KO/hHO-1/hA20 transgenic pigs are a promising model to alleviate rejection and ischemia-reperfusion damage in porcine xenografts and could serve as a background for further genetic modifications toward the production of a donor pig that is clinically relevant for xenotransplantation.

Species-specific regulation of fibrinogen synthesis with implications for porcine hepatocyte xenotransplantation.

BACKGROUND: Patients with liver failure could potentially be bridged with porcine xenogeneic liver cell transplantation. We examined species-specific differences between primary human and porcine hepatocytes in the regulation of coagulation protein expression and function. METHODS: Isolated primary human and porcine hepatocytes were stimulated with either porcine or human interleukin (IL)-6 (10 ng/ml), IL-1ß (10 ng/ml), and tumor necrosis factor-alpha (TNF-α, 30 ng/ml). mRNA expression of coagulation factors were measured by RT-PCR and real-time PCR. Cell culture supernatants were used for the measurement of fibrinogen by ELISA and determination of fibrin clot generation. RESULTS: Fibrinogen expression in human hepatocytes increased after IL-6 treatment (P = 0.010) and decreased after TNF-α treatment (P = 0.005). Porcine hepatocytes displayed a lower increase in fibrinogen expression after IL-6 treatment as compared to hepatocytes of human origin (P = 0.021). Porcine hepatocytes responded contrarily following TNF-α treatment with an increased expression of fibrinogen resulting in a significant species-specific difference between human and porcine hepatocytes (P = 0.029). Fibrin polymer generation by human hepatocytes was stable and widely branched after IL-6 treatment, while stimulation with TNF-α displayed no fibrin generation at all. In contrast, treatment of porcine hepatocytes with TNF-α resulted in generation of a stable and widely branched fibrin polymer, and stimulation with IL-6 only leads to generation of partial fibrin aggregates. CONCLUSION: We identified species-specific differences in the regulation of fibrinogen mRNA expression and fibrin generation under inflammatory stimuli. In hepatic xenotransplantation of porcine origin, these interspecies differences might lead to a loss of physiological coagulation function and a loss of transplanted cells.