Requirements elicitation step is of paramount importance in the requirements engineering process. In the distributed environment of so-called inter-company cooperative information system, this step is a thorny issue. ...Requirements elicitation step is of paramount importance in the requirements engineering process. In the distributed environment of so-called inter-company cooperative information system, this step is a thorny issue. To elicit require-ments for an inter-company cooperative information system, we early proposed a methodology called MAMIE (from MAcro to MIcro level requirements Elicitation) with an accompanied tool. In MAMIE methodology, requirements are the result of composing functional and non-functional concerns. Before non-functional concerns composition, it’s primary to identify relationships between them. According to the most existing approaches, a non-functional concern may have a negative, positive or null contribution on the other non-functional concerns. In this paper, we argue that using only these three contributions types is not sufficient to express relationships which may exist between non-functional concerns. Thus, we propose a process which aims to identify non-functional concerns’ relationships and model them using a fuzzy cognitive map. The resulting model is composed of non-functional concerns, relationships between them and the weight of these relationships expressed with linguistics fuzzy values. Using fuzzy cognitive maps to model non-functional concerns relationships allows moving from the conventional modelling toward developing a computer based model. An example from the textile industry is used to illustrate the applicability of our process.展开更多
In the process of oxidative phosphorylation, protons are pumped into the intermembrane space to establish the mitochondrial membrane potential (MMP). Relying on the electrochemical gradient, protons can return to the ...In the process of oxidative phosphorylation, protons are pumped into the intermembrane space to establish the mitochondrial membrane potential (MMP). Relying on the electrochemical gradient, protons can return to the matrix through the ATP synthase complex with ATP generation. MitoQ, a lipophilic cation drug, can be bsorbed to the inner mitochondrial membrane with the cationic moiety staying at the intermembrane space[1].展开更多
In clinical practice,pancreatic neuroendocrine neoplasms(pNENs)with a diameter smaller than 2 cm are commonly referred to as small pNENs.Due to their generally favorable biological characteristics,the diagnosis and tr...In clinical practice,pancreatic neuroendocrine neoplasms(pNENs)with a diameter smaller than 2 cm are commonly referred to as small pNENs.Due to their generally favorable biological characteristics,the diagnosis and treatment of small pNENs differ from other pNENs and are somewhat controversial.In response to this,the Chinese Pancreatic Surgery Association,Chinese Society of Surgery,Chinese Medical Association have developed a consensus on the diagnosis and treatment of small pNENs,which is based on evidence-based medicine and expert opinions.This consensus covers various topics,including concepts,disease assessment,treatment selection,follow-up,and other relevant aspects.展开更多
Background: Primary non-function(PNF) and early allograft failure(EAF) after liver transplantation(LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipien...Background: Primary non-function(PNF) and early allograft failure(EAF) after liver transplantation(LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipients at high risk of PNF and EAF were urgently needed. Recently, the Model for Early Allograft Function(MEAF), PNF score by King's College(King-PNF) and Balance-and-Risk-Lactate(BAR-Lac) score were developed to assess the risks of PNF and EAF. This study aimed to externally validate and compare the prognostic performance of these three scores for predicting PNF and EAF. Methods: A retrospective study included 720 patients with primary LT between January 2015 and December 2020. MEAF, King-PNF and BAR-Lac scores were compared using receiver operating characteristic(ROC) and the net reclassification improvement(NRI) and integrated discrimination improvement(IDI) analyses. Results: Of all 720 patients, 28(3.9%) developed PNF and 67(9.3%) developed EAF in 3 months. The overall early allograft dysfunction(EAD) rate was 39.0%. The 3-month patient mortality was 8.6% while 1-year graft-failure-free survival was 89.2%. The median MEAF, King-PNF and BAR-Lac scores were 5.0(3.5–6.3),-2.1(-2.6 to-1.2), and 5.0(2.0–11.0), respectively. For predicting PNF, MEAF and King-PNF scores had excellent area under curves(AUCs) of 0.872 and 0.891, superior to BAR-Lac(AUC = 0.830). The NRI and IDI analyses confirmed that King-PNF score had the best performance in predicting PNF while MEAF served as a better predictor of EAD. The EAF risk curve and 1-year graft-failure-free survival curve showed that King-PNF was superior to MEAF and BAR-Lac scores for stratifying the risk of EAF. Conclusions: MEAF, King-PNF and BAR-Lac were validated as practical and effective risk assessment tools of PNF. King-PNF score outperformed MEAF and BAR-Lac in predicting PNF and EAF within 6 months. BAR-Lac score had a huge advantage in the prediction for PNF without post-transplant variables. Proper use of these scores will help early identify PNF, standardize grading of EAF and reasonably select clinical endpoints in relative studies.展开更多
The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human re...The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human resources to translate these into clear functional and non-functional requirements.To address this challenge,various machine learning(ML)methods have been explored to automate the understanding of these requirements,aiming to reduce time and human effort.However,existing techniques often struggle with complex instructions and large-scale projects.In our study,we introduce an innovative approach known as the Functional and Non-functional Requirements Classifier(FNRC).By combining the traditional random forest algorithm with the Accuracy Sliding Window(ASW)technique,we develop optimal sub-ensembles that surpass the initial classifier’s accuracy while using fewer trees.Experimental results demonstrate that our FNRC methodology performs robustly across different datasets,achieving a balanced Precision of 75%on the PROMISE dataset and an impressive Recall of 85%on the CCHIT dataset.Both datasets consistently maintain an F-measure around 64%,highlighting FNRC’s ability to effectively balance precision and recall in diverse scenarios.These findings contribute to more accurate and efficient software development processes,increasing the probability of achieving successful project outcomes.展开更多
Objective:To evaluate the epidemiological,demographic,clinical features,treatment approaches,and survival of patients followed up for adrenal incidentaloma.Methods:Data from 46 patients who were treated and followed u...Objective:To evaluate the epidemiological,demographic,clinical features,treatment approaches,and survival of patients followed up for adrenal incidentaloma.Methods:Data from 46 patients who were treated and followed up due to adrenal incidentaloma in the Endocrinology Department of Mersin University Health Research and Application Hospital between 2010 and 2014 were retrospectively analyzed.Results:Of the cases included in the study,13 were male,33 were female,and the mean age was 54.09±10.7 years.The most common reason for admission was abdominal pain in 34.78%of the patients,the most commonly diagnosed radiological method was dynamic adrenal CT in 60.87%,and the most common location was the left adrenal gland.The mean lesion diameter was between 26.8±16.5 mm.The frequency of hypertension was 50%,obesity 47.8%,type 2 diabetes 21.7%,osteoporosis 42.8%,and metabolic syndrome 41.3%.According to hormonal evaluation results,non-functional adrenal adenoma(NFAA)was found in 82.61%,subclinical Cushing’s syndrome(SCS)in 15.21%,and aldosteronoma in 2.1%.Myelolipoma,pheochromocytoma,and adrenocortical adenoma were diagnosed in 8 cases undergoing adrenalectomy.One patient died due to liver failure.No hormonal activation or growth in lesion size was detected during the follow-up of the patients.Conclusion:Due to the very different pathological and radiological appearances of adrenal incidentaloma,it is important to evaluate demographic,etiological,clinical,laboratory,and radiological data as a whole in the treatment and follow-up.展开更多
OBJECTIVE The current retrospective study aims to evaluate the management of non-functioning the assessment of experience on pituitary macroadenoma through clinical, biochemical, radiological features, and treatment o...OBJECTIVE The current retrospective study aims to evaluate the management of non-functioning the assessment of experience on pituitary macroadenoma through clinical, biochemical, radiological features, and treatment outcome of patients, and to identify prognostic factors affecting progression-free survival (PFS). METHODS Data of 55 patients macroadenoma presented to the with non-functioning pituitary Clinical Oncology and Nuclear Medicine department between 1998 and 2009 were investigated. RESULTS The most common symptom was visual disturbance (38.2%) followed by headache (27.3%). The presence of male predominance was observed (1.4:1). Ten patients received radio-therapy (RT) only. Extrasellar extension was the more common treatment. The overall response rate was 72.8% with completed response at 16.4%. Memory and intellectual sequelae were the most common late complications of treatment (14%). The ten-year PFS was at 84.6%. PFS was found to be significantly better with higher dose of RT (up to 54 Gy), treatment by both surgery and RT, absence of visual field defect, and tumor localized to sella, whereas it was not significantly affected by age and sex. CONCLUSION The data confirmed that the prevalence of mass effect and hypopituitarism in patients with non-functioning pituitary macroadenoma is elevated. Conventional external RT up to 54 Gy is safe and effective in controlling non-functioning pituitary macro- adenoma with tolerable and acceptable morbidity.展开更多
Introduction: Despite the fact that non-functioning pituitary adenomas do not overproduce hormones, many will stain positive for a particular pituitary hormone, which can be used to differentiate these adenomas into s...Introduction: Despite the fact that non-functioning pituitary adenomas do not overproduce hormones, many will stain positive for a particular pituitary hormone, which can be used to differentiate these adenomas into subgroups. If these different sub-groups behave differently in terms of post surgical progression of disease (PSPD) rates or other clinical variables, then better treatment and prognosis could be predicted. Methods: This was a retrospective cohort study. Patients who have undergone surgery for removal of a non-functioning pituitary adenoma at Emory University Hospital served as the source for all data used in this study (n = 184). Data were collected from a database of electronic medical records (EMRs) for these patients in 2010 documenting clinical and demographic variables including treatment and PSPD. Results: Risk for PSPD did not differ by adenoma subtypes: follicle-stimulating hormone (FSH+), luteinizing hormone (LH+), or those that do not stain positive for any hormone (non-functioning, or NF?) (p = 0.971). There were two clinical characteristics statistically related to adenoma subtype: altered mental status and the anterior-posterior (AP) dimension of pre-operative adenomas. PSPD was related to several clinical characteristics, including gender, previous adenoma, post-operative residual, and follow-up time.展开更多
NFMAs are benign tumors that do not produce any biologically active hormones and exceed 10 mm (0.39 in) in size. Although NFMAs are benign in origin, mass effects may lead to serious clinical symptoms such as visual i...NFMAs are benign tumors that do not produce any biologically active hormones and exceed 10 mm (0.39 in) in size. Although NFMAs are benign in origin, mass effects may lead to serious clinical symptoms such as visual impairments, chronic headache, and pituitary insufficiency. The authors describe a 51-year-old woman who had a NFMA (35 × 24 × 25 mm). The vision was reduced to 7/10 in the both eyes. A transnasal transsphenoidal surgery was performed and the tumor was successfully resected. Postoperatively, the patient had visual (9/10) and headache improvement. This case highlights a rare presentation of non-functioning pituitary macroadenoma.展开更多
Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex...Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.展开更多
Objective:To compare the differences in postoperative survival and complications between extended right liver transplantation(ERLT)and whole liver transplantation(WLT).Methods:The Chinese and English databases were se...Objective:To compare the differences in postoperative survival and complications between extended right liver transplantation(ERLT)and whole liver transplantation(WLT).Methods:The Chinese and English databases were searched for clinical studies on comparing ERLT with WLT for end-stage liver disease from the date of database construction to April 15,2022.The searched literature was de-duplicated and selected according to the order of title,abstract and content,after which NOS quality evaluation was performed for literature that matched the study.Postoperative complications and survival data were extracted from the eligible literature and subjected to Meta-analysis with Review Manager 5.3,and finally data sensitivity analysis and publication bias tests were performed.Results:The complication of ERLT such as biliary complications[OR=1.77,95%CI=(1.39,2.25),P<0.00001],biliary leakage[OR=2.16,95%CI=(1.64,2.84),P<0.0001],total vascular complications[OR=2.00,95%CI=(1.48,2.70),P<0.0001],hepatic arterial thrombosis[OR=2.06,95%CI=(1.50,2.83),P<0.00001],re-Transplantation[OR=1.93,95%CI=(1.53,2.45),P<0.00001]have a higher occurrence rate compared with WLT.While the biliary stenosis[OR=0.74,95%CI=(0.48,1.15),P=0.18],hepatic portal vein thrombosis[OR=1.72,95%CI=(0.84,3.49),P=0.14],primary non-function[OR=1.27,95%CI=(0.80,2.02),P=0.32]had no statistically difference in the incidence of complications after liver transplantation.In terms of survival,ERLT had lower 1-year graft survival rate[OR=0.64,95%CI=(0.54,0.76),P<0.00001]and patient survival rate[OR=0.75,95%CI=(0.62,0.91),P=0.003]than WLT.Fortunately,there was no statistically difference in 5-year graft survival rate[OR=0.97,95%CI=(0.76,1.23),P=0.78]and 5-year patient survival rate[OR=0.94,95%CI=(0.78,1.14),P=0.54].Conclusion:ERLT is a safe and effective treatment for adult end-stage liver disease.As a surgical method with postoperative complications and survival similar to that of WLT,ERLT can increase the source of donor liver.展开更多
BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experienc...BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation,as a specific topic in the field of kidney transplantation.AIM To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation(SKT).METHODS The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed.Beside the descriptive characteristics,the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves.In addition,Kaplan-Meier analyses were also used to estimate the survival probabilities at 1,3,5,and 10 post-operative years,as well as at the longest followup duration available.Moreover,bivariate associations between various predictors and the categorical outcomes were assessed,using the suitable biostatistical tests,according to the predictor type.RESULTS Out of 1861 cases of kidney transplantation,only 48 cases with SKT were eligible for studying,including 33 men and 15 women with a mean age of 42.1±13 years.The primary non-function(PNF)graft occurred in five patients(10.4%).In bivariate analyses,a high body mass index(P=0.009)and first graft loss due to acute rejection(P=0.025)were the only significant predictors of PNF graft.The second graft survival was reduced by delayed graft function in the first(P=0.008)and second(P<0.001)grafts.However,the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance(P=0.053).The mean follow-up period was 59.8±48.6 mo.Censored graft/patient survival rates at 1,3,5 and 10 years were 90.5%/97.9%,79.9%/95.6%,73.7%/91.9%,and 51.6%/83.0%,respectively.CONCLUSION Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates.Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.展开更多
This paper presents the notion of the global execution context of a task as a representational construct for analysing complexity in software evolution. Based on this notion a visual notation and a supporting tool are...This paper presents the notion of the global execution context of a task as a representational construct for analysing complexity in software evolution. Based on this notion a visual notation and a supporting tool are presented to support specification of a system’s global execution context. A system’s global execution context is conceived as an evolving network of use scenarios depicted by nodes and links designating semantic relationships between scenarios. A node represents either a base or a growth scenario. Directed links characterize the transition from one node to another by means of semantic scenario relationships. Each growth scenario is generated following a critique (or screening) of one or more base or reference scenarios. Subsequently, representative growth scenarios are compiled and consolidated in the global execution context graph. The paper describes the stages of this process, presents the tool designed to facilitate the construction of the global execution context graph and elaborates on recent practice and experience.展开更多
Design Patterns, which give abstract solutions to commonly recurring design problems, have been widely used in the software and hardware domain. As non-functional requirements are an important aspect in the design of ...Design Patterns, which give abstract solutions to commonly recurring design problems, have been widely used in the software and hardware domain. As non-functional requirements are an important aspect in the design of safety-critical embedded systems, this work focuses on the integration of non-functional implications in an existing design pattern concept. We propose a pattern representation for safety-critical embedded application design methods by including fields for the implications and side effects of the represented design pattern on the non-functional requirements of the overall systems. The considered requirements include safety, reliability, modifiability, cost, and execution time.展开更多
This paper presents CBAM Assistant, a tool that semi-automates the Cost Benefit Analysis Method (CBAM) developed by the Software Engineering Institute (SEI) at Carnegie Mellon University. CBAM is a process used to est...This paper presents CBAM Assistant, a tool that semi-automates the Cost Benefit Analysis Method (CBAM) developed by the Software Engineering Institute (SEI) at Carnegie Mellon University. CBAM is a process used to estimate the Return on Investment (ROI) of various software architectural design strategies. CBAM generally follows the Architectural Trade-off Analysis Method (ATAM) also developed by SEI. ATAM aids in defining scenarios and architectural strategies. The result is a qualitative trade-off analysis of the various strategies. CBAM further refines the scenarios and architectural strategies from ATAM. CBAM aids in quantitative analysis for cost, utility and importance ratings to determine the ROI of each architectural strategy. CBAM Assistant is a web-based system that walks a user through the CBAM process which can be started by using scenarios and architectural strategies created from ATAM. The tool is intended to be used by a facilitator who will provide input from stakeholders. The primary output of the tool is the ROIs of each architectural strategy for comparison and selection.展开更多
The last decade saw increased organ donation activity from donors after cardiac death (DCD). This contributed to a signif icant proportion of transplant activity. Despite certain drawbacks, liver transplantation from ...The last decade saw increased organ donation activity from donors after cardiac death (DCD). This contributed to a signif icant proportion of transplant activity. Despite certain drawbacks, liver transplantation from DCD donors continues to supplement the donor pool on the backdrop of a severe organ shortage. Understanding the pathophysiology has provided the basis for modulation of DCD organs that has been proven to be effective outside liver transplantation but remains experimental in liver transplantation models. Research continues on how best to further increase the utility of DCD grafts. Most of the work has been carried out exploring the use of organ preservation using machine assisted perfusion. Both ex-situ and in-situ organ perfusion systems are tested in the liver transplantation setting with promising results. Additional techniques involved pharmacological manipulation of the donor, graft and the recipient. Ethical barriers and end-of-life care pathways are obstacles to widespread clinical application of some of the recent advances to practice. It is likely that some of the DCD offers are in fact probably "prematurely" of-fered without ideal donor management or even prior to brain death being established. The absolute benef its of DCD exist only if this form of donation supplements the existing deceased donor pool; hence, it is worthwhile revisiting organ donation process enabling us to identify counter remedial measures.展开更多
BACKGROUND: Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay a...BACKGROUND: Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.DATA SOURCE: A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.RESULTS: There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia reperfusion injury is considered the direct cause. Potentia managements which are helpful to improve graft function were investigated. Some of them are promising.CONCLUSIONS: Our analyses suggested that the definition of PGD should include one or more of the following variables: (1)bilirubin ≥10 mg/dL on postoperative day 7; (2) internationa normalized ratio ≥1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase 】2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses intoprimary non-function, the patients need to be treated with retransplantation.展开更多
Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse ou...Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1<sup>th</sup> and the 5<sup>th</sup> day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.展开更多
AIM To compare the effects of the four most commonly used preservation solutions on the outcome of liver transplantations.METHODS A systematic literature search was performed using MEDLINE, Scopus, EMBASE and the Coch...AIM To compare the effects of the four most commonly used preservation solutions on the outcome of liver transplantations.METHODS A systematic literature search was performed using MEDLINE, Scopus, EMBASE and the Cochrane Library databases up to January 31^(st), 2017. The inclusion criteria were comparative, randomized controlled trials(RCTs) for deceased donor liver(DDL) allografts with adult and pediatric donors using the gold standard University of Wisconsin(UW) solution or histidinetryptophan-ketoglutarate(HTK), Celsior(CS) and Institut Georges Lopez(IGL-1) solutions. Fifteen RCTs(1830 livers) were included; the primary outcomes were primary non-function(PNF) and one-year posttransplant graft survival(OGS-1). RESULTS All trials were homogenous with respect to donor and recipient characteristics. There was no statistical difference in the incidence of PNF with the use of UW, HTK, CS and IGL-1(RR = 0.02, 95%CI: 0.01-0.03, P = 0.356). Comparing OGS-1 also failed to reveal any difference between UW, HTK, CS and IGL-1(RR = 0.80, 95%CI: 0.80-0.80, P = 0.369). Two trials demonstrated higher PNF levels for UW in comparison with the HTK group, and individual studies described higher rates of biliary complications where HTK and CS were used compared to the UW and IGL-1 solutions. However, the meta-analysis of the data did not prove a statistically significant difference: the UW, CS, HTK and IGL-1 solutions were associated with nearly equivalent outcomes.CONCLUSION Alternative solutions for UW yield the same degree of safety and effectiveness for the preservation of DDLs, but further well-designed clinical trials are warranted.展开更多
BACKGROUND: Liver transplantation is a life-saving the- rapeutic modality for patients with end-stage liver diseases. After liver transplantation, however, more than 10% pa- tients may lose the grafts caused by a vari...BACKGROUND: Liver transplantation is a life-saving the- rapeutic modality for patients with end-stage liver diseases. After liver transplantation, however, more than 10% pa- tients may lose the grafts caused by a variety of reasons. This review covers the most frequent indications for liver retransplantation as well as the results and specific problems with each indication. DATA RESOURCES: Searching MEDLINE (1997-2003) for articles on liver retransplantation. RESULTS: The most frequent indications of liver retrans- plantation are primary non-function, hepatic artery throm- bosis, graft rejection and recurrent diseases. The results af- ter liver retransplantation remain inferior to those after first transplantation. CONCLUSION: Liver retransplantation, which is the only means of prolonging survival in those patients whose initial graft has failed, makes an important contribution to overall survival.展开更多
文摘Requirements elicitation step is of paramount importance in the requirements engineering process. In the distributed environment of so-called inter-company cooperative information system, this step is a thorny issue. To elicit require-ments for an inter-company cooperative information system, we early proposed a methodology called MAMIE (from MAcro to MIcro level requirements Elicitation) with an accompanied tool. In MAMIE methodology, requirements are the result of composing functional and non-functional concerns. Before non-functional concerns composition, it’s primary to identify relationships between them. According to the most existing approaches, a non-functional concern may have a negative, positive or null contribution on the other non-functional concerns. In this paper, we argue that using only these three contributions types is not sufficient to express relationships which may exist between non-functional concerns. Thus, we propose a process which aims to identify non-functional concerns’ relationships and model them using a fuzzy cognitive map. The resulting model is composed of non-functional concerns, relationships between them and the weight of these relationships expressed with linguistics fuzzy values. Using fuzzy cognitive maps to model non-functional concerns relationships allows moving from the conventional modelling toward developing a computer based model. An example from the textile industry is used to illustrate the applicability of our process.
基金Key Program of National Natural Science Foundation of China (U1432248), National Natural Science Foundation of China (11505245), Western Talent Program of Chinese Academy of Sciences (Y460040XB0)
文摘In the process of oxidative phosphorylation, protons are pumped into the intermembrane space to establish the mitochondrial membrane potential (MMP). Relying on the electrochemical gradient, protons can return to the matrix through the ATP synthase complex with ATP generation. MitoQ, a lipophilic cation drug, can be bsorbed to the inner mitochondrial membrane with the cationic moiety staying at the intermembrane space[1].
基金supported by the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)2021-I2M-1-002.
文摘In clinical practice,pancreatic neuroendocrine neoplasms(pNENs)with a diameter smaller than 2 cm are commonly referred to as small pNENs.Due to their generally favorable biological characteristics,the diagnosis and treatment of small pNENs differ from other pNENs and are somewhat controversial.In response to this,the Chinese Pancreatic Surgery Association,Chinese Society of Surgery,Chinese Medical Association have developed a consensus on the diagnosis and treatment of small pNENs,which is based on evidence-based medicine and expert opinions.This consensus covers various topics,including concepts,disease assessment,treatment selection,follow-up,and other relevant aspects.
基金supported by grants from the National Nat-ural Science Foundation of China (81570587 and 81700557)the Guangdong Provincial Key Laboratory Construction Projection on Organ Donation and Transplant Immunology (2013A061401007 and 2017B030314018)+3 种基金Guangdong Provincial Natural Science Funds for Major Basic Science Culture Project (2015A030308010)Science and Technology Program of Guangzhou (201704020150)the Natural Science Foundations of Guangdong province (2016A030310141 and 2020A1515010091)Young Teachers Training Project of Sun Yat-sen University (K0401068) and the Guangdong Science and Technology Innovation Strategy (pdjh2022b0010 and pdjh2023a0002)。
文摘Background: Primary non-function(PNF) and early allograft failure(EAF) after liver transplantation(LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipients at high risk of PNF and EAF were urgently needed. Recently, the Model for Early Allograft Function(MEAF), PNF score by King's College(King-PNF) and Balance-and-Risk-Lactate(BAR-Lac) score were developed to assess the risks of PNF and EAF. This study aimed to externally validate and compare the prognostic performance of these three scores for predicting PNF and EAF. Methods: A retrospective study included 720 patients with primary LT between January 2015 and December 2020. MEAF, King-PNF and BAR-Lac scores were compared using receiver operating characteristic(ROC) and the net reclassification improvement(NRI) and integrated discrimination improvement(IDI) analyses. Results: Of all 720 patients, 28(3.9%) developed PNF and 67(9.3%) developed EAF in 3 months. The overall early allograft dysfunction(EAD) rate was 39.0%. The 3-month patient mortality was 8.6% while 1-year graft-failure-free survival was 89.2%. The median MEAF, King-PNF and BAR-Lac scores were 5.0(3.5–6.3),-2.1(-2.6 to-1.2), and 5.0(2.0–11.0), respectively. For predicting PNF, MEAF and King-PNF scores had excellent area under curves(AUCs) of 0.872 and 0.891, superior to BAR-Lac(AUC = 0.830). The NRI and IDI analyses confirmed that King-PNF score had the best performance in predicting PNF while MEAF served as a better predictor of EAD. The EAF risk curve and 1-year graft-failure-free survival curve showed that King-PNF was superior to MEAF and BAR-Lac scores for stratifying the risk of EAF. Conclusions: MEAF, King-PNF and BAR-Lac were validated as practical and effective risk assessment tools of PNF. King-PNF score outperformed MEAF and BAR-Lac in predicting PNF and EAF within 6 months. BAR-Lac score had a huge advantage in the prediction for PNF without post-transplant variables. Proper use of these scores will help early identify PNF, standardize grading of EAF and reasonably select clinical endpoints in relative studies.
基金This work is supported by EIAS(Emerging Intelligent Autonomous Systems)Data Science Lab,Prince Sultan University,Kingdom of Saudi Arabia,by paying the APC.
文摘The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human resources to translate these into clear functional and non-functional requirements.To address this challenge,various machine learning(ML)methods have been explored to automate the understanding of these requirements,aiming to reduce time and human effort.However,existing techniques often struggle with complex instructions and large-scale projects.In our study,we introduce an innovative approach known as the Functional and Non-functional Requirements Classifier(FNRC).By combining the traditional random forest algorithm with the Accuracy Sliding Window(ASW)technique,we develop optimal sub-ensembles that surpass the initial classifier’s accuracy while using fewer trees.Experimental results demonstrate that our FNRC methodology performs robustly across different datasets,achieving a balanced Precision of 75%on the PROMISE dataset and an impressive Recall of 85%on the CCHIT dataset.Both datasets consistently maintain an F-measure around 64%,highlighting FNRC’s ability to effectively balance precision and recall in diverse scenarios.These findings contribute to more accurate and efficient software development processes,increasing the probability of achieving successful project outcomes.
文摘Objective:To evaluate the epidemiological,demographic,clinical features,treatment approaches,and survival of patients followed up for adrenal incidentaloma.Methods:Data from 46 patients who were treated and followed up due to adrenal incidentaloma in the Endocrinology Department of Mersin University Health Research and Application Hospital between 2010 and 2014 were retrospectively analyzed.Results:Of the cases included in the study,13 were male,33 were female,and the mean age was 54.09±10.7 years.The most common reason for admission was abdominal pain in 34.78%of the patients,the most commonly diagnosed radiological method was dynamic adrenal CT in 60.87%,and the most common location was the left adrenal gland.The mean lesion diameter was between 26.8±16.5 mm.The frequency of hypertension was 50%,obesity 47.8%,type 2 diabetes 21.7%,osteoporosis 42.8%,and metabolic syndrome 41.3%.According to hormonal evaluation results,non-functional adrenal adenoma(NFAA)was found in 82.61%,subclinical Cushing’s syndrome(SCS)in 15.21%,and aldosteronoma in 2.1%.Myelolipoma,pheochromocytoma,and adrenocortical adenoma were diagnosed in 8 cases undergoing adrenalectomy.One patient died due to liver failure.No hormonal activation or growth in lesion size was detected during the follow-up of the patients.Conclusion:Due to the very different pathological and radiological appearances of adrenal incidentaloma,it is important to evaluate demographic,etiological,clinical,laboratory,and radiological data as a whole in the treatment and follow-up.
文摘OBJECTIVE The current retrospective study aims to evaluate the management of non-functioning the assessment of experience on pituitary macroadenoma through clinical, biochemical, radiological features, and treatment outcome of patients, and to identify prognostic factors affecting progression-free survival (PFS). METHODS Data of 55 patients macroadenoma presented to the with non-functioning pituitary Clinical Oncology and Nuclear Medicine department between 1998 and 2009 were investigated. RESULTS The most common symptom was visual disturbance (38.2%) followed by headache (27.3%). The presence of male predominance was observed (1.4:1). Ten patients received radio-therapy (RT) only. Extrasellar extension was the more common treatment. The overall response rate was 72.8% with completed response at 16.4%. Memory and intellectual sequelae were the most common late complications of treatment (14%). The ten-year PFS was at 84.6%. PFS was found to be significantly better with higher dose of RT (up to 54 Gy), treatment by both surgery and RT, absence of visual field defect, and tumor localized to sella, whereas it was not significantly affected by age and sex. CONCLUSION The data confirmed that the prevalence of mass effect and hypopituitarism in patients with non-functioning pituitary macroadenoma is elevated. Conventional external RT up to 54 Gy is safe and effective in controlling non-functioning pituitary macro- adenoma with tolerable and acceptable morbidity.
文摘Introduction: Despite the fact that non-functioning pituitary adenomas do not overproduce hormones, many will stain positive for a particular pituitary hormone, which can be used to differentiate these adenomas into subgroups. If these different sub-groups behave differently in terms of post surgical progression of disease (PSPD) rates or other clinical variables, then better treatment and prognosis could be predicted. Methods: This was a retrospective cohort study. Patients who have undergone surgery for removal of a non-functioning pituitary adenoma at Emory University Hospital served as the source for all data used in this study (n = 184). Data were collected from a database of electronic medical records (EMRs) for these patients in 2010 documenting clinical and demographic variables including treatment and PSPD. Results: Risk for PSPD did not differ by adenoma subtypes: follicle-stimulating hormone (FSH+), luteinizing hormone (LH+), or those that do not stain positive for any hormone (non-functioning, or NF?) (p = 0.971). There were two clinical characteristics statistically related to adenoma subtype: altered mental status and the anterior-posterior (AP) dimension of pre-operative adenomas. PSPD was related to several clinical characteristics, including gender, previous adenoma, post-operative residual, and follow-up time.
文摘NFMAs are benign tumors that do not produce any biologically active hormones and exceed 10 mm (0.39 in) in size. Although NFMAs are benign in origin, mass effects may lead to serious clinical symptoms such as visual impairments, chronic headache, and pituitary insufficiency. The authors describe a 51-year-old woman who had a NFMA (35 × 24 × 25 mm). The vision was reduced to 7/10 in the both eyes. A transnasal transsphenoidal surgery was performed and the tumor was successfully resected. Postoperatively, the patient had visual (9/10) and headache improvement. This case highlights a rare presentation of non-functioning pituitary macroadenoma.
文摘Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.
基金Key Science and Technology Project of Hainan Province(No.ZDK2019009)Construction of Clinical Medical Center of Hainan Province(Organ Transplantation)。
文摘Objective:To compare the differences in postoperative survival and complications between extended right liver transplantation(ERLT)and whole liver transplantation(WLT).Methods:The Chinese and English databases were searched for clinical studies on comparing ERLT with WLT for end-stage liver disease from the date of database construction to April 15,2022.The searched literature was de-duplicated and selected according to the order of title,abstract and content,after which NOS quality evaluation was performed for literature that matched the study.Postoperative complications and survival data were extracted from the eligible literature and subjected to Meta-analysis with Review Manager 5.3,and finally data sensitivity analysis and publication bias tests were performed.Results:The complication of ERLT such as biliary complications[OR=1.77,95%CI=(1.39,2.25),P<0.00001],biliary leakage[OR=2.16,95%CI=(1.64,2.84),P<0.0001],total vascular complications[OR=2.00,95%CI=(1.48,2.70),P<0.0001],hepatic arterial thrombosis[OR=2.06,95%CI=(1.50,2.83),P<0.00001],re-Transplantation[OR=1.93,95%CI=(1.53,2.45),P<0.00001]have a higher occurrence rate compared with WLT.While the biliary stenosis[OR=0.74,95%CI=(0.48,1.15),P=0.18],hepatic portal vein thrombosis[OR=1.72,95%CI=(0.84,3.49),P=0.14],primary non-function[OR=1.27,95%CI=(0.80,2.02),P=0.32]had no statistically difference in the incidence of complications after liver transplantation.In terms of survival,ERLT had lower 1-year graft survival rate[OR=0.64,95%CI=(0.54,0.76),P<0.00001]and patient survival rate[OR=0.75,95%CI=(0.62,0.91),P=0.003]than WLT.Fortunately,there was no statistically difference in 5-year graft survival rate[OR=0.97,95%CI=(0.76,1.23),P=0.78]and 5-year patient survival rate[OR=0.94,95%CI=(0.78,1.14),P=0.54].Conclusion:ERLT is a safe and effective treatment for adult end-stage liver disease.As a surgical method with postoperative complications and survival similar to that of WLT,ERLT can increase the source of donor liver.
基金this study were approved by the Ethical Committee(Institutional Review Board,IRB)of the Faculty of Medicine,Assiut University,Egypt and Martin-Luther University,Germany(IRB approval number:17200548/2015).
文摘BACKGROUND The increasing kidney retransplantation rate has created a parallel field of research,including the risk factors and outcomes of this advanced form of renal replacement therapy.The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation,as a specific topic in the field of kidney transplantation.AIM To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation(SKT).METHODS The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed.Beside the descriptive characteristics,the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves.In addition,Kaplan-Meier analyses were also used to estimate the survival probabilities at 1,3,5,and 10 post-operative years,as well as at the longest followup duration available.Moreover,bivariate associations between various predictors and the categorical outcomes were assessed,using the suitable biostatistical tests,according to the predictor type.RESULTS Out of 1861 cases of kidney transplantation,only 48 cases with SKT were eligible for studying,including 33 men and 15 women with a mean age of 42.1±13 years.The primary non-function(PNF)graft occurred in five patients(10.4%).In bivariate analyses,a high body mass index(P=0.009)and first graft loss due to acute rejection(P=0.025)were the only significant predictors of PNF graft.The second graft survival was reduced by delayed graft function in the first(P=0.008)and second(P<0.001)grafts.However,the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance(P=0.053).The mean follow-up period was 59.8±48.6 mo.Censored graft/patient survival rates at 1,3,5 and 10 years were 90.5%/97.9%,79.9%/95.6%,73.7%/91.9%,and 51.6%/83.0%,respectively.CONCLUSION Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates.Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.
文摘This paper presents the notion of the global execution context of a task as a representational construct for analysing complexity in software evolution. Based on this notion a visual notation and a supporting tool are presented to support specification of a system’s global execution context. A system’s global execution context is conceived as an evolving network of use scenarios depicted by nodes and links designating semantic relationships between scenarios. A node represents either a base or a growth scenario. Directed links characterize the transition from one node to another by means of semantic scenario relationships. Each growth scenario is generated following a critique (or screening) of one or more base or reference scenarios. Subsequently, representative growth scenarios are compiled and consolidated in the global execution context graph. The paper describes the stages of this process, presents the tool designed to facilitate the construction of the global execution context graph and elaborates on recent practice and experience.
文摘Design Patterns, which give abstract solutions to commonly recurring design problems, have been widely used in the software and hardware domain. As non-functional requirements are an important aspect in the design of safety-critical embedded systems, this work focuses on the integration of non-functional implications in an existing design pattern concept. We propose a pattern representation for safety-critical embedded application design methods by including fields for the implications and side effects of the represented design pattern on the non-functional requirements of the overall systems. The considered requirements include safety, reliability, modifiability, cost, and execution time.
文摘This paper presents CBAM Assistant, a tool that semi-automates the Cost Benefit Analysis Method (CBAM) developed by the Software Engineering Institute (SEI) at Carnegie Mellon University. CBAM is a process used to estimate the Return on Investment (ROI) of various software architectural design strategies. CBAM generally follows the Architectural Trade-off Analysis Method (ATAM) also developed by SEI. ATAM aids in defining scenarios and architectural strategies. The result is a qualitative trade-off analysis of the various strategies. CBAM further refines the scenarios and architectural strategies from ATAM. CBAM aids in quantitative analysis for cost, utility and importance ratings to determine the ROI of each architectural strategy. CBAM Assistant is a web-based system that walks a user through the CBAM process which can be started by using scenarios and architectural strategies created from ATAM. The tool is intended to be used by a facilitator who will provide input from stakeholders. The primary output of the tool is the ROIs of each architectural strategy for comparison and selection.
文摘The last decade saw increased organ donation activity from donors after cardiac death (DCD). This contributed to a signif icant proportion of transplant activity. Despite certain drawbacks, liver transplantation from DCD donors continues to supplement the donor pool on the backdrop of a severe organ shortage. Understanding the pathophysiology has provided the basis for modulation of DCD organs that has been proven to be effective outside liver transplantation but remains experimental in liver transplantation models. Research continues on how best to further increase the utility of DCD grafts. Most of the work has been carried out exploring the use of organ preservation using machine assisted perfusion. Both ex-situ and in-situ organ perfusion systems are tested in the liver transplantation setting with promising results. Additional techniques involved pharmacological manipulation of the donor, graft and the recipient. Ethical barriers and end-of-life care pathways are obstacles to widespread clinical application of some of the recent advances to practice. It is likely that some of the DCD offers are in fact probably "prematurely" of-fered without ideal donor management or even prior to brain death being established. The absolute benef its of DCD exist only if this form of donation supplements the existing deceased donor pool; hence, it is worthwhile revisiting organ donation process enabling us to identify counter remedial measures.
文摘BACKGROUND: Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.DATA SOURCE: A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.RESULTS: There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia reperfusion injury is considered the direct cause. Potentia managements which are helpful to improve graft function were investigated. Some of them are promising.CONCLUSIONS: Our analyses suggested that the definition of PGD should include one or more of the following variables: (1)bilirubin ≥10 mg/dL on postoperative day 7; (2) internationa normalized ratio ≥1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase 】2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses intoprimary non-function, the patients need to be treated with retransplantation.
文摘Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1<sup>th</sup> and the 5<sup>th</sup> day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.
基金Supported by grants from the National Research Development and Innovation Office,NKFI K120232Hungarian Science Research Fund,No.GINOP 2.3.2-15-2016-00015 and No.EFOP-3.6.2-16-2017-00006New National Excellence Program of the Ministry of Human Capacities,No.UNKP-17-4
文摘AIM To compare the effects of the four most commonly used preservation solutions on the outcome of liver transplantations.METHODS A systematic literature search was performed using MEDLINE, Scopus, EMBASE and the Cochrane Library databases up to January 31^(st), 2017. The inclusion criteria were comparative, randomized controlled trials(RCTs) for deceased donor liver(DDL) allografts with adult and pediatric donors using the gold standard University of Wisconsin(UW) solution or histidinetryptophan-ketoglutarate(HTK), Celsior(CS) and Institut Georges Lopez(IGL-1) solutions. Fifteen RCTs(1830 livers) were included; the primary outcomes were primary non-function(PNF) and one-year posttransplant graft survival(OGS-1). RESULTS All trials were homogenous with respect to donor and recipient characteristics. There was no statistical difference in the incidence of PNF with the use of UW, HTK, CS and IGL-1(RR = 0.02, 95%CI: 0.01-0.03, P = 0.356). Comparing OGS-1 also failed to reveal any difference between UW, HTK, CS and IGL-1(RR = 0.80, 95%CI: 0.80-0.80, P = 0.369). Two trials demonstrated higher PNF levels for UW in comparison with the HTK group, and individual studies described higher rates of biliary complications where HTK and CS were used compared to the UW and IGL-1 solutions. However, the meta-analysis of the data did not prove a statistically significant difference: the UW, CS, HTK and IGL-1 solutions were associated with nearly equivalent outcomes.CONCLUSION Alternative solutions for UW yield the same degree of safety and effectiveness for the preservation of DDLs, but further well-designed clinical trials are warranted.
文摘BACKGROUND: Liver transplantation is a life-saving the- rapeutic modality for patients with end-stage liver diseases. After liver transplantation, however, more than 10% pa- tients may lose the grafts caused by a variety of reasons. This review covers the most frequent indications for liver retransplantation as well as the results and specific problems with each indication. DATA RESOURCES: Searching MEDLINE (1997-2003) for articles on liver retransplantation. RESULTS: The most frequent indications of liver retrans- plantation are primary non-function, hepatic artery throm- bosis, graft rejection and recurrent diseases. The results af- ter liver retransplantation remain inferior to those after first transplantation. CONCLUSION: Liver retransplantation, which is the only means of prolonging survival in those patients whose initial graft has failed, makes an important contribution to overall survival.