Mechanical and morphological characterization of the emphysematous lung tissue.

Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions.

Effect of positive end-expiratory pressure on lung injury and haemodynamics during experimental acute respiratory distress syndrome treated with extracorporeal membrane oxygenation and near-apnoeic ventilation.

Background: Lung rest has been recommended during extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS). Whether positive end-expiratory pressure (PEEP) confers lung protection during ECMO for severe ARDS is unclear. We compared the effects of three different PEEP levels whilst applying near-apnoeic ventilation in a model of severe ARDS treated with ECMO.

A physiological approach to understand the role of respiratory effort in the progression of lung injury in SARS-CoV-2 infection.

Deterioration of lung function during the first week of COVID-19 has been observed when patients remain with insufficient respiratory support. Patient self-inflicted lung injury (P-SILI) is theorized as the responsible, but there is not robust experimental and clinical data to support it. Given the limited understanding of P-SILI, we describe the physiological basis of P-SILI and we show experimental data to comprehend the role of regional strain and heterogeneity in lung injury due to increased work of breathing.

Progression of regional lung strain and heterogeneity in lung injury: assessing the evolution under spontaneous breathing and mechanical ventilation.

Background: Protective mechanical ventilation (MV) aims at limiting global lung deformation and has been associated with better clinical outcomes in acute respiratory distress syndrome (ARDS) patients. In ARDS lungs without MV support, the mechanisms and evolution of lung tissue deformation remain understudied. In this work, we quantify the progression and heterogeneity of regional strain in injured lungs under spontaneous breathing and under MV.

Mapping regional strain in anesthetised healthy subjects during spontaneous ventilation.

Introduction: Breathing produces a phenomenon of cyclic deformation throughout life. Biomechanically, deformation of the lung is measured as strain. Regional strain recently started to be recognised as a tool in the study of lung pathophysiology, but regional lung strain has not been studied in healthy subjects breathing spontaneously without voluntary or pharmacological control of ventilation.

Positive end-expiratory pressure improves elastic working pressure in anesthetized children.

Background: Positive end-expiratory pressure (PEEP) has been demonstrated to decrease ventilator-induced lung injury in patients under mechanical ventilation (MV) for acute respiratory failure. Recently, some studies have proposed some beneficial effects of PEEP in ventilated patients without lung injury. The influence of PEEP on respiratory mechanics in children is not well known.

Near-Apneic Ventilation Decreases Lung Injury and Fibroproliferation in an Acute Respiratory Distress Syndrome Model with Extracorporeal Membrane Oxygenation.

Rationale: There is wide variability in mechanical ventilation settings during extracorporeal membrane oxygenation (ECMO) in patients with acute respiratory distress syndrome. Although lung rest is recommended to prevent further injury, there is no evidence to support it.

Objectives: To determine whether near-apneic ventilation decreases lung injury in a pig model of acute respiratory distress syndrome supported with ECMO.

Implementation of preemptive fluid strategy as a bundle to prevent fluid overload in children with acute respiratory distress syndrome and sepsis.

Background: Fluid overload (FO) is associated with unfavorable outcomes in critically ill children. Clinicians are encouraged to avoid FO; however, strategies to avoid FO are not well-described in pediatrics. Our aim was to implement a bundle strategy to prevent FO in children with sepsis and pARDS and to compare the outcomes with a historical cohort.

Extracorporeal membrane oxygenation improves survival in a novel 24-hour pig model of severe acute respiratory distress syndrome.

Extracorporeal membrane oxygenation (ECMO) is increasingly being used to treat severe acute respiratory distress syndrome (ARDS). However, there is limited clinical evidence about how to optimize the technique. Experimental research can provide an alternative to fill the actual knowledge gap.

Regenerative Potential of Mesenchymal Stromal Cells: Age-Related Changes.

Preclinical and clinical studies have shown that a therapeutic effect results from mesenchymal stromal cells (MSCs) transplant. No systematic information is currently available regarding whether donor age modifies MSC regenerative potential on cutaneous wound healing. Here, we evaluate whether donor age influences this potential.

Decreased lung compliance increases preload dynamic tests in a pediatric acute lung injury model.

Background: Preload dynamic tests, pulse pressure variation (PPV) and stroke volume variation (SVV) have emerged as powerful tools to predict response to fluid administration. The influence of factors other than preload in dynamic preload test is currently poorly understood in pediatrics. The aim of our study was to assess the effect of tidal volume (VT) on PPV and SVV in the context of normal and reduced lung compliance in a piglet model.

[Genetic predisposition and Pediatric Acute Respiratory Distress Syndrome: New tools for genetic study].

Acute respiratory distress syndrome (ARDS) is the most severe form of respiratory failure. Theoretically, any acute lung condition can lead to ARDS, but only a small percentage of individuals actually develop the disease. On this basis, genetic factors have been implicated in the risk of developing ARDS.

Mild hypothermia increases pulmonary anti-inflammatory response during protective mechanical ventilation in a piglet model of acute lung injury.

Background: The effects of mild hypothermia (HT) on acute lung injury (ALI) are unknown in species with metabolic rate similar to that of humans, receiving protective mechanical ventilation (MV). We hypothesized that mild hypothermia would attenuate pulmonary and systemic inflammatory responses in piglets with ALI managed with a protective MV.

Methods: Acute lung injury (ALI) was induced with surfactant deactivation in 38 piglets.

Surfactant deactivation in a pediatric model induces hypovolemia and fluid shift to the extravascular lung compartment.

Background: Surfactant deficiency is the pivotal abnormality in Neonatal and Acute Respiratory Distress Syndrome. Surfactant deactivation can produce hypoxemia, loss of lung compliance, and pulmonary edema, but its circulatory consequences are less understood.

Objective: To describe the sequential hemodynamic changes and pulmonary edema formation after surfactant deactivation in piglets.

[Veno-arterial difference of carbon dioxide as a predictor of low cardiac output in an experimental pediatric model].

Background: Cardiac output (CO) measurement is not a standard of care for critically ill children, but it can be estimated by indirect methods such as veno-arterial pCO2 difference (ΔVACO2).

Aim: To determine the correlation between CO and ΔVACO2 and evaluate the usefulness of ΔVACO2 in the diagnosis of low CO in an experimental pediatric model.

Materials And Methods: Thirty piglets weighing 4.

Mild hypothermia attenuates lung edema and plasma interleukin-1β in a rat mechanical ventilation-induced lung injury model.

Recent data suggest that deep hypothermia has protective effects on experimental induced lung injury. It is not well known if these effects persist with mild hypothermia. The authors hypothesized that mild hypothermia may attenuate lung injury and decrease local and systemic proinflammatory cytokines in a rat model of injurious mechanical ventilation (MV).

Angiotensin-converting enzyme insertion/deletion polymorphism is associated with severe hypoxemia in pediatric ARDS.

Purpose: The D allele of the insertion/deletion (I/D) polymorphism of a 287-bp sequence in the angiotensin-converting enzyme (ACE) gene has been associated with an increased activity of this enzyme. Its role in susceptibility to acute respiratory distress syndrome (ARDS) has not been well defined. We hypothesized that ACE I/D genotype in pediatrics is associated with ARDS and plasma levels of angiotensin II.

Peripheral cytokine profile in Chilean patients with Crohn's disease and ulcerative colitis.

Crohn's disease (CD) and ulcerative colitis (UC) belong to the group of inflammatory bowel diseases (IBD), with complex ethiopathogenic factors that include an unbalanced immune and inflammatory response to commensal and food antigens. The differential diagnosis between CD and UC is performed using clinical, endoscopic, histopathological, serological and radiological methods; however between 10-15% of IBD patients are diagnosed as "unclassified colitis". Further research into IBD is necessary in order to develop additional diagnostic tools.

Megalin and cubilin expression in gallbladder epithelium and regulation by bile acids.

Cholesterol crystal formation in the gallbladder is a key step in gallstone pathogenesis. Gallbladder epithelial cells might prevent luminal gallstone formation through a poorly understood cholesterol absorption process. Genetic studies in mice have highlighted potential gallstone susceptibility alleles, Lith genes, which include the gene for megalin.