The physics of spreading processes in multilayer networks

The study of networks plays a crucial role in investigating the structure, dynamics, and function of a wide variety of complex systems in myriad disciplines. Despite the success of traditional network analysis, standard networks provide a limited representation of complex systems, which often include different types of relationships (i.e., "multiplexity") among their constituent components and/or multiple interacting subsystems. Such structural complexity has a significant effect on both dynamics and function. Throwing away or aggregating available structural information can generate misleading results and be a major obstacle towards attempts to understand complex systems. The recent "multilayer" approach for modeling networked systems explicitly allows the incorporation of multiplexity and other features of realistic systems. On one hand, it allows one to couple different structural relationships by encoding them in a convenient mathematical object. On the other hand, it also allows one to couple different dynamical processes on top of such interconnected structures. The resulting framework plays a crucial role in helping achieve a thorough, accurate understanding of complex systems. The study of multilayer networks has also revealed new physical phenomena that remain hidden when using ordinary graphs, the traditional network representation. Here we survey progress towards attaining a deeper understanding of spreading processes on multilayer networks, and we highlight some of the physical phenomena related to spreading processes that emerge from multilayer structure.Comment: 25 pages, 4 figure

Plasma copeptin as biomarker of disease progression and prognosis in cirrhosis

Lay summary: Copeptin is a fragment of the vasopressin precursor, a hormone that is known to be increased in patients with cirrhosis and that plays a role in the development of complications of the disease. Vasopressin is difficult to measure, but copeptin is a more stable molecule and is easier to measure in blood. Sola and Kerbert and colleagues have shown in a series of 361 patients that copeptin is markedly increased in patients with cirrhosis who develop complications during the following 3 months, compared to those patients who do not develop complications. Moreover, copeptin correlates with prognosis. (C) 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

The PREDICT study uncovers three clinical courses of acutely decompensated cirrhosis that have distinct pathophysiology

Background & Aims: Acute decompensation (AD) of cirrhosis is defined as the acute development of ascites, gastrointestinal hemorrhage, hepatic encephalopathy, infection or any combination thereof, requiring hospitalization. The presence of organ failure(s) in patients with AD defines acute-on-chronic liver failure (ACLF). The PREDICT study is a European, prospective, observational study, designed to characterize the clinical course of AD and to identify predictors of ACLF. Methods: A total of 1,071 patients with AD were enrolled. We collected detailed pre-specified information on the 3-month period prior to enrollment, and clinical and laboratory data at enrollment. Patients were then closely followed up for 3 months. Outcomes (liver transplantation and death) at 1 year were also recorded. Results: Three groups of patients were identified. Pre-ACLF patients (n = 218) developed ACLF and had 3-month and 1-year mortality rates of 53.7% and 67.4%, respectively. Unstable decompensated cirrhosis (UDC) patients (n = 233) required ≥1 readmission but did not develop ACLF and had mortality rates of 21.0% and 35.6%, respectively. Stable decompensated cirrhosis (SDC) patients (n = 620) were not readmitted, did not develop ACLF and had a 1-year mortality rate of only 9.5%. The 3 groups differed significantly regarding the grade and course of systemic inflammation (high-grade at enrollment with aggravation during follow-up in pre-ACLF; low-grade at enrollment with subsequent steady-course in UDC; and low-grade at enrollment with subsequent improvement in SDC) and the prevalence of surrogates of severe portal hypertension throughout the study (high in UDC vs. low in pre-ACLF and SDC). Conclusions: Acute decompensation without ACLF is a heterogeneous condition with 3 different clinical courses and 2 major pathophysiological mechanisms: systemic inflammation and portal hypertension. Predicting the development of ACLF remains a major future challenge. ClinicalTrials.gov number: NCT03056612. Lay summary: Herein, we describe, for the first time, 3 different clinical courses of acute decompensation (AD) of cirrhosis after hospital admission. The first clinical course includes patients who develop acute-on-chronic liver failure (ACLF) and have a high short-term risk of death – termed pre-ACLF. The second clinical course (unstable decompensated cirrhosis) includes patients requiring frequent hospitalizations unrelated to ACLF and is associated with a lower mortality risk than pre-ACLF. Finally, the third clinical course (stable decompensated cirrhosis), includes two-thirds of all patients admitted to hospital with AD – patients in this group rarely require hospital admission and have a much lower 1-year mortality risk

La percepción del paciente crítico sobre los cuidados enfermeros: una aproximación al concepto de satisfacción

Introducción: El grado de satisfacción es un indicador fundamental de la calidad asistencial. Existen numerosos instrumentos que miden la satisfacción con los cuidados enfermeros, aunque no responden a la realidad del paciente crítico ni a nuestro contexto. Objetivos: Explorar y comprender la satisfacción de los pacientes ingresados en Cuidados Intensivos de un hospital nivel iii con los cuidados enfermeros, para definir e identificar las dimensiones del concepto de satisfacción desde su punto de vista. Material y métodos: Estudio cualitativo según la teoría fundamentada en 3 unidades de Cuidados Intensivos de 34 boxes individuales. Muestreo teórico. La muestra, tras la saturación de datos, fue de 19 participantes. La recogida de datos fue a través de la entrevista en profundidad y diario de campo. Análisis de contenido según teoría fundamentada. Se siguieron los criterios de rigor de Guba y Lincoln. Informe favorable del comité de ética del centro y consentimiento informado. Resultados: Emergen 4 categorías: definición y dimensiones del concepto de satisfacción, expectativas y vivencias. Los participantes incluyen en su definición de satisfacción las dimensiones: competencias profesionales, cuidados humanos, técnicos y continuados. La combinación de estos elementos produce sentimientos de seguridad, tranquilidad, estar vigilado, sentirse persona, percibiendo una relación cercana y de confianza con la enfermera que realiza cuidados individualizados. Conclusiones: La definición y las dimensiones del concepto de satisfacción desde el punto de vista del paciente muestran los aspectos importantes para la persona además de clarificar sus dimensiones, permitiendo la construcción de instrumentos más acordes con el contexto y su percepción real

Urinary L-FABP is a promising prognostic biomarker of ACLF and mortality in patients with decompensated cirrhosis

Background & Aims: Decompensated cirrhosis (DC) is associated with high mortality, mainly owing to the development of acute-on-chronic liver failure (ACLF). Identifying the patients with DC who are at high risk of mortality and ACLF development is an unmet clinical need. Liver fatty acid-binding protein (L-FABP) is expressed in several organs and correlates with liver and systemic inflammation. Herein, we aimed to assess the prognostic value of L-FABP in patients with DC. Methods: A prospective series of 444 patients hospitalized for DC was divided into 2 cohorts: study cohort (305 patients) and validation cohort (139 patients). L-FABP was measured in urine and plasma samples collected at admission. Neutrophil gelatinase-associated lipocalin (NGAL) was also measured in urine samples for comparison. Results: Urine but not plasma L-FABP correlated with 3-month survival on univariate analysis. On multivariate analysis, urine L-FABP and model for end-stage liver disease (MELD)-Na were the only independent predictors of prognosis. Urine L-FABP levels were higher in patients with ACLF than in those without and also predicted the development of ACLF, together with MELD-Na, during follow-up. In patients with ACLF, urine L-FABP correlated with liver, coagulation, and circulatory failure. Urine L-FABP levels were also increased in patients with acute kidney injury, particularly in those with acute tubular necrosis. The ability of urinary L-FABP to predict survival and ACLF development was confirmed in the validation cohort. Urine NGAL predicted outcome on univariate but not multivariate analysis. Conclusions: Urinary L-FABP levels are independently associated with the 3-month clinical course in patients with DC, in terms of mortality and ACLF development. Urinary L-FABP is a promising prognostic biomarker for patients with DC. Lay summary: Increased levels of liver fatty acid-binding protein (L-FABP), a protein related to lipid metabolism, have been associated with liver-related diseases. The present study analyzed urinary L-FABP levels in 2 independent groups of patients with decompensated cirrhosis and showed that higher urinary L-FABP levels correlated with increased mortality and risk of acute-on-chronic liver failure development. Therefore, urinary L-FABP levels could be useful as a new tool to predict complications in patients with decompensated cirrhosis

Treatment With Simvastatin and Rifaximin Restores the Plasma Metabolomic Profile in Patients With Decompensated Cirrhosis

Patients with decompensated cirrhosis, particularly those with acute-on-chronic liver failure (ACLF), show profound alterations in plasma metabolomics. The aim of this study was to investigate the effect of treatment with simvastatin and rifaximin on plasma metabolites of patients with decompensated cirrhosis, specifically on compounds characteristic of the ACLF plasma metabolomic profile. Two cohorts of patients were investigated. The first was a descriptive cohort of patients with decompensated cirrhosis (n = 42), with and without ACLF. The second was an intervention cohort from the LIVERHOPE-SAFETY randomized, double-blind, placebo-controlled trial treated with simvastatin 20 mg/day plus rifaximin 1,200 mg/day (n = 12) or matching placebo (n = 13) for 3 months. Plasma samples were analyzed using ultrahigh performance liquid chromatography–tandem mass spectroscopy for plasma metabolomics characterization. ACLF was characterized by intense proteolysis and lipid alterations, specifically in pathways associated with inflammation and mitochondrial dysfunction, such as the tryptophan–kynurenine and carnitine beta-oxidation pathways. An ACLF-specific signature was identified. Treatment with simvastatin and rifaximin was associated with changes in 161 of 985 metabolites in comparison to treatment with placebo. A remarkable reduction in levels of metabolites from the tryptophan–kynurenine and carnitine pathways was found. Notably, 18 of the 32 metabolites of the ACLF signature were affected by the treatment. Conclusion: Treatment with simvastatin and rifaximin modulates some of the pathways that appear to be key in ACLF development. This study unveils some of the mechanisms involved in the effects of treatment with simvastatin and rifaximin in decompensated cirrhosis and sets the stage for the use of metabolomics to investigate new targeted therapies in cirrhosis to prevent ACLF development

PREDICT identifies precipitating events associated with the clinical course of acutely decompensated cirrhosis

Background & Aims: Acute decompensation (AD) of cirrhosis may present without acute-on-chronic liver failure (ACLF) (ADNo ACLF), or with ACLF (AD-ACLF), defined by organ failure(s). Herein, we aimed to analyze and characterize the precipitants leading to both of these AD phenotypes. Methods: The multicenter, prospective, observational PREDICT study (NCT03056612) included 1,273 non-electively hospitalized patients with AD (No ACLF = 1,071; ACLF = 202). Medical history, clinical data and laboratory data were collected at enrolment and during 90-day follow-up, with particular attention given to the following characteristics of precipitants: induction of organ dysfunction or failure, systemic inflammation, chronology, intensity, and relationship to outcome. Results: Among various clinical events, 4 distinct events were precipitants consistently related to AD: proven bacterial infections, severe alcoholic hepatitis, gastrointestinal bleeding with shock and toxic encephalopathy. Among patients with precipitants in the AD-No ACLF cohort and the AD-ACLF cohort (38% and 71%, respectively), almost all (96% and 97%, respectively) showed proven bacterial infection and severe alcoholic hepatitis, either alone or in combination with other events. Survival was similar in patients with proven bacterial infections or severe alcoholic hepatitis in both AD phenotypes. The number of precipitants was associated with significantly increased 90day mortality and was paralleled by increasing levels of surrogates for systemic inflammation. Importantly, adequate first-line antibiotic treatment of proven bacterial infections was associated with a lower ACLF development rate and lower 90-day mortality. Conclusions: This study identified precipitants that are significantly associated with a distinct clinical course and prognosis in patients with AD. Specific preventive and therapeutic strategies targeting these events may improve outcomes in patients with decompensated cirrhosis. Lay summary: Acute decompensation (AD) of cirrhosis is characterized by a rapid deterioration in patient health. Herein, we aimed to analyze the precipitating events that cause AD in patients with cirrhosis. Proven bacterial infections and severe alcoholic hepatitis, either alone or in combination, accounted for almost all (96-97%) cases of AD and acute-on-chronic liver failure. Whilst the type of precipitant was not associated with mortality, the number of precipitant(s) was. This study identified precipitants that are significantly associated with a distinct clinical course and prognosis of patients with AD. Specific preventive and therapeutic strategies targeting these events may improve patient outcomes. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Cellular mechanisms in basic and clinical gastroenterology and hepatolog

PREDICT identifies precipitating events associated with the clinical course of acutely decompensated cirrhosis.

INTRODUCTION: Acute decompensation (AD) of cirrhosis may present without acute-on-chronic liver failure (ACLF) (AD-No ACLF), or with ACLF phenotype (AD-ACLF) defined by organ failure(s). Precipitants may induce AD. This multicenter, prospective, observational PREDICT study (NCT03056612) analyzes and characterizes the precipitants leading to both of these AD phenotypes. PATIENTS AND METHODS: The PREDICT study included 1273 non-electively hospitalized patients with AD (No-ACLF=1071; ACLF=202). Medical history, clinical and laboratory data were collected at enrolment and during 90-day follow up, with particular attention to the following characteristics of precipitants: induction of organ dysfunction or failure, systemic inflammation, chronology, intensity, and relationship to outcome. RESULTS: Among various clinical events, four distinct events were precipitants consistently related to AD, including proven bacterial infections, severe alcoholic hepatitis, gastrointestinal (GI) bleeding with shock and toxic encephalopathy. Among patients with precipitants in the AD-No ACLF cohort and the AD-ACLF cohort (38% and 71%, respectively), almost all (96% and 97%, respectively) showed proven bacterial infection and severe alcoholic hepatitis, either alone or in combination with other events. In both AD phenotypes, patients with proven bacterial infections or severe alcoholic hepatitis had a similar survival. The number of precipitants was associated with significantly increased 90-day mortality, and was paralleled by increasing levels of surrogates for systemic inflammation. Importantly, adequate first-line antibiotic treatment of proven bacterial infections was associated with lower ACLF development rate and lower 90-day mortality. CONCLUSIONS: This study identified precipitants that are significantly associated with a distinct clinical course and prognosis of patients with AD and specific preventive and therapeutic strategies targeting these events may improve outcome in decompensated cirrhosis.status: Published onlin