67 research outputs found
Procurement and ex-situ perfusion of isolated slaughterhouse-derived livers as a model of donors after circulatory death_suppl
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A Bayesian Network Approach for the Interpretation of Cyber Attacks to Power Systems
The focus of this paper is on the analysis of the cyber security
resilience of digital infrastructures deployed by power grids, internationally recognized as a priority since several recent cyber attacks targeted
energy systems and in particular the power service. In response to the
regulatory framework, this paper presents an analysis approach based
on the Bayesian Networks formalism and on real world threat scenarios.
Our approach enables analyses oriented to planning of security measures
and monitoring, and to forecasting of adversarial behaviours
Analisi e rilevamento intelligente di processi di attacco alle Smart-Grid
Proponiamo una metodologia basata sulle Reti Bayesiane come strumento di supporto all’analisi della sicurezza di Smart Grid, ed in particolare per la previsione di intrusioni e attività ostili
Analysis of new control applications
This document reports the results of the activities performed during the first year of the CRUTIAL project, within the Work Package 1 "Identification and description of Control System Scenarios". It represents the outcome of the analysis of new control applications in the Power
System and the identification of critical control system scenarios to be explored by the CRUTIAL project
Lung anatomy, energy load, and ventilator-induced lung injury
High tidal volume can cause ventilator-induced lung injury (VILI), but positive end-expiratory pressure (PEEP) is thought to be protective. We aimed to find the volumetric VILI threshold and see whether PEEP is protective per se or indirectly
Methodology for clinical research
A clinical research requires a systematic approach with diligent planning, execution and sampling in order to obtain reliable and validated results, as well as an understanding of each research methodology is essential for researchers. Indeed, selecting an inappropriate study type, an error that cannot be corrected after the beginning of a study, results in flawed methodology. The results of clinical research studies enhance the repertoire of knowledge regarding a disease pathogenicity, an existing or newly discovered medication, surgical or diagnostic procedure or medical device. Medical research can be divided into primary and secondary research, where primary research involves conducting studies and collecting raw data, which is then analysed and evaluated in secondary research. The successful deployment of clinical research methodology depends upon several factors. These include the type of study, the objectives, the population, study design, methodology/techniques and the sampling and statistical procedures used. Among the different types of clinical studies, we can recognize descriptive or analytical studies, which can be further categorized in observational and experimental. Finally, also pre-clinical studies are of outmost importance, representing the steppingstone of clinical trials. It is therefore important to understand the types of method for clinical research. Thus, this review focused on various aspects of the methodology and describes the crucial steps of the conceptual and executive stages
Ethical considerations regarding animal experimentation
Animal experimentation is widely used around the world for the identification of the root causes of various diseases in humans and animals and for exploring treatment options. Among the several animal species, rats, mice and purpose-bred birds comprise almost 90% of the animals that are used for research purpose. However, growing awareness of the sentience of animals and their experience of pain and suffering has led to strong opposition to animal research among many scientists and the general public. In addition, the usefulness of extrapolating animal data to humans has been questioned. This has led to Ethical Committees’ adoption of the ‘four Rs’ principles (Reduction, Refinement, Replacement and Responsibility) as a guide when making decisions regarding animal experimentation. Some of the essential considerations for humane animal experimentation are presented in this review along with the requirement for investigator training. Due to the ethical issues surrounding the use of animals in experimentation, their use is declining in those research areas where alternative in vitro or in silico methods are available. However, so far it has not been possible to dispense with experimental animals completely and further research is needed to provide a road map to robust alternatives before their use can be fully discontinued
Utilization of livers donated after circulatory death for transplantation - An international comparison.
BACKGROUND AND AIM
Liver graft utilization rates are a hot topic due to the worldwide organ shortage and an increasing number of transplant candidates on waiting lists. Liver perfusion techniques have been introduced in several countries, and may help to increase the organ supply, as they potentially allow the assessment of livers before use.
METHODS
Liver offers were counted from donation after circulatory death (DCD) donors (Maastricht-type-III) arising during the past decade in eight countries, including Belgium, France, Italy, the Netherlands, Spain, Switzerland, UK, and US. Initial DCD-type-III liver offers were correlated with accepted, recovered and implanted livers.
RESULTS
A total number of 34`269 DCD livers were offered, resulting in 9`780 liver transplants (28.5%). The discard rates were highest in UK and US, ranging between 70 and 80%. In contrast, much lower DCD liver discard rates, e.g., between 30-40%, were found in Belgium, France, Italy, Spain and Switzerland. In addition, large differences were recognized in the use of various machine perfusion techniques, and in terms of risk factors in the cohorts of implanted livers. For example, the median donor age and functional donor warm ischemia were highest in Italy, e.g., >40minutes, followed by Switzerland, France, and the Netherlands. Importantly, such varying risk profiles of accepted DCD livers between countries did not translate into large differences in five-year graft survival rates, which ranged between 60-82% in this analysis.
CONCLUSIONS
We highlight a significant number of discarded and consequently unused DCD liver offers. Countries with more routine use of in- and ex-situ machine perfusion strategies showed better DCD utilization rates without compromised outcome.
IMPACT AND IMPLICATIONS
A significant number of Maastricht type III DCD livers are discarded across Europe and North America today. The overall utilization rate among eight Western countries is 28.5%, but varies significantly between 18.9% and 74.2%. For example, the median DCD III liver utilization in five countries, e.g., Belgium, France, Italy, Switzerland, and Spain is 65%, in contrast to 24% in the Netherlands, UK and US. Despite this, and despite different rules and strategies for organ acceptance and preservation, the one and five-year graft survival remains currently relatively comparable among all participating countries. Factors which impact on DCD liver acceptance rates include the national pre-selections of donors, before the offer is made, as well as cutoffs for key risk factors, including donor age and donor warm ischemia time. In addition, a highly varying experience with modern machine perfusion technology is noticed. In situ and ex situ liver perfusion concepts, and assessment tools for type III DCD livers before transplantation may be one key part for the observed differences in better DCD III utilization
Visceral Artery Aneurysms in Liver Transplant Candidates and in Patients after Liver Transplantation
There are only few reviews concerning visceral aneurysms in cirrhotics, and a small number of papers on visceral aneurysms in liver transplant patients. The present paper investigates this condition in both groups of patients in a 10-year-retrospective study
A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation
BACKGROUND: To identify the best possible outcomes in liver transplantation from donation after circulatory death donors (DCD) and to propose outcome values, which serve as reference for individual liver recipients or patient groups. METHODS: Based on 2219 controlled DCD liver transplantations, collected from 17 centres in North America and Europe, we identified 1012 low-risk, primary, adult liver transplantations with a laboratory MELD of ≤20points, receiving a DCD liver with a total donor warm ischemia time of ≤30minutes and asystolic donor warm ischemia time of ≤15minutes. Clinically relevant outcomes were selected and complications were reported according to the Clavien-Dindo-Grading and the Comprehensive Complication Index (CCI). Corresponding benchmark cut-offs were based on median values of each centre, where the 75(th)-percentile was considered. RESULTS: Benchmark cases represented between 19.7% and 75% of DCD transplantations in participating centers. The one-year retransplant and mortality rate was 5.23% and 9.01%, respectively. Within the first year of follow-up, 51.1% of recipients developed at least one major complication (≥Clavien-Dindo-Grade-III). Benchmark cut-offs were ≤3days and ≤16days for ICU and hospital stay, ≤66% for severe recipient complications (≥Grade-III), ≤16.8% for ischemic cholangiopathy, and ≤38.9CCI points at one-year posttransplant. Comparisons with higher risk groups showed more complications and impaired graft survival, outside the benchmark cut-offs. Organ perfusion techniques reduced the complications to values below benchmark cut-offs, despite higher graft risk. CONCLUSIONS: Despite excellent 1-year survival, morbidity in benchmark cases remains high with more than half of recipients developing severe complications during 1-year follow-up. Benchmark cut-offs targeting morbidity parameters offer a valid tool to assess the protective value of new preservation technologies in higher risk groups, and provide a valid comparator cohort for future clinical trials. LAY SUMMARY: The best possible outcomes after liver transplantation of grafts donated after circulatory death (DCD) were defined using the concept of benchmarking. These were based on 2219 liver transplantations following controlled DCD donation in 17 centres worldwide. The following benchmark cut-offs for the most relevant outcome parameters were developed: ICU and hospital stay: ≤3 and ≤16 days; primary non function: ≤2.5%; renal replacement therapy: ≤9.6%; ischemic cholangiopathy: ≤16.8% and anastomotic strictures ≤28.4%. One-year graft loss and mortality were defined as ≤14.4% and 9.6%, respectively. Donor and recipient combinations with higher risk had significantly worse outcomes. The use of novel organ perfusion technology achieved similar, good results in this high-risk group with prolonged donor warm ischemia time, when compared to the benchmark cohort
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