Changes in the Concentrations of Mediators of Inflammation and Oxidative Stress in Exhaled Breath Condensate During Liver Transplantation and Their Relations With Postoperative ARDS

Interesting effects of interleukins and immune cells on acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a medical condition characterized by widespread inflammation in the lungs with consequent proportional loss of gas exchange function. ARDS is linked with severe pulmonary or systemic infection. Several factors, including secretory cytokines, immune cells, and lung epithelial and endothelial cells, play a role in the development and progression of this disease. The present study is based on Pubmed database information (1987-2022) using the words "Acute respiratory distress syndrome", "Interleukin", "Cytokines" and "Immune cells". Cytokines and immune cells play an important role in this disease, with particular emphasis on the balance between pro-inflammatory and anti-inflammatory factors. Neutrophils are one of several important mediators of Inflammation, lung tissue destruction, and malfunction during ARDS. Some immune cells, such as macrophages and eosinophils, play a dual role in releasing inflammatory mediators, recruitment inflammatory cells and the progression of ARDS, or releasing anti-inflammatory mediators, clearing the lung of inflammatory cells, and helping to improve the disease. Different interleukins play a role in the development or inhibition of ARDS by helping to activate various signaling pathways, helping to secrete other inflammatory or anti-inflammatory interleukins, and playing a role in the production and balance between immune cells involved in ARDS. As a result, immune cells and, inflammatory cytokines, especially interleukins play an important role in the pathogenesis of this disease Therefore, understanding the relevant mechanisms will help in the proper diagnosis and treatment of this disease.

Therapeutic effects of minocycline on oleic acid-induced acute respiratory distress syndrome (ARDS) in rats

Acute respiratory distress syndrome (ARDS) is a serious intensive care condition. Despite advances in treatment over the previous few decades, ARDS patients still have high fatality rates. Thus, more research is needed to improve the outcomes for people with ARDS. Minocycline is an antibiotic with antioxidant, anti-inflammatory, and anti-apoptotic effects. In the current investigation, the therapeutic effects of minocycline on oleic acid-induced ARDS were evaluated. Male rats were classified into 6 groups, 1. control (normal saline), 2. oleic acid (100 µL, i.v.), 3-5. oleic acid + minocycline (50, 100, 200 mg/kg, i.p.), and 6. minocycline (200 mg/kg, i.p.) alone. Twenty-four hours after the oleic acid injection, the lung tissue is isolated, weighed, and the middle part of the right lung is immediately placed in the freezer, while the middle part of the left lung is placed in formalin and sent to the laboratory for pathology testing. Then, the amounts of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), cytokines (interleukin-1 beta (IL-1β), tumor necrosis factor-α (TNF-α)), B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), and cleaved caspase-3 were determined in lung tissue. Administration of oleic acid increased emphysema, inflammation, vascular congestion, hemorrhage, MDA amount, Bax/Bcl-2 ratio, cleaved caspase-3, IL-1β, TNF-α levels, and decreased GSH, SOD, and CAT levels in comparison with the control group. The administration of minocycline could significantly reduce pathological and biochemical alterations induced by oleic acid. Minocycline has a therapeutic effect on oleic acid-induced ARDS through antioxidant, anti-inflammatory, and anti-apoptotic properties.

Biomarkers of mitochondrial dysfunction in acute respiratory distress syndrome: A systematic review and meta-analysis

Introduction

Acute respiratory distress syndrome (ARDS) is one of the main causes of Intensive Care Unit morbidity and mortality. Metabolic biomarkers of mitochondrial dysfunction are correlated with disease development and high mortality in many respiratory conditions, however it is not known if they can be used to assess risk of mortality in patients with ARDS.

Objectives

The aim of this systematic review was to examine the link between recorded biomarkers of mitochondrial dysfunction in ARDS and mortality.

Methods

A systematic review of CINAHL, EMBASE, MEDLINE, and Cochrane databases was performed. Studies had to include critically ill ARDS patients with reported biomarkers of mitochondrial dysfunction and mortality. Information on the levels of biomarkers reflective of energy metabolism and mitochondrial respiratory function, mitochondrial metabolites, coenzymes, and mitochondrial deoxyribonucleic acid (mtDNA) copy number was recorded. RevMan5.4 was used for meta-analysis. Biomarkers measured in the samples representative of systemic circulation were analyzed separately from the biomarkers measured in the samples representative of lung compartment. Cochrane risk of bias tool and Newcastle-Ottawa scale were used to evaluate publication bias (Prospero protocol: CRD42022288262).

Results

Twenty-five studies were included in the systematic review and nine had raw data available for follow up meta-analysis. Biomarkers of mitochondrial dysfunction included mtDNA, glutathione coupled mediators, lactate, malondialdehyde, mitochondrial genetic defects, oxidative stress associated markers. Biomarkers that were eligible for meta-analysis inclusion were: xanthine, hypoxanthine, acetone, N-pentane, isoprene and mtDNA. Levels of mitochondrial biomarkers were significantly higher in ARDS than in non-ARDS controls (P = 0.0008) in the blood-based samples, whereas in the BAL the difference did not reach statistical significance (P = 0.14). mtDNA was the most frequently measured biomarker, its levels in the blood-based samples were significantly higher in ARDS compared to non-ARDS controls (P = 0.04). Difference between mtDNA levels in ARDS non-survivors compared to ARDS survivors did not reach statistical significance (P = 0.05).

Conclusion

Increased levels of biomarkers of mitochondrial dysfunction in the blood-based samples are positively associated with ARDS. Circulating mtDNA is the most frequently measured biomarker of mitochondrial dysfunction, with significantly elevated levels in ARDS patients compared to non-ARDS controls. Its potential to predict risk of ARDS mortality requires further investigation.

Systematic review registration

[https://www.crd.york.ac.uk/prospero], identifier [CRD42022288262].

Perioperative Exhaled Nitric Oxide as an Indicator for Postoperative Pneumonia in Surgical Lung Cancer Patients: A Prospective Cohort Study Based on 183 Cases

Introduction

This study is conducted to investigate the correlation between perioperative fractional exhaled nitric oxide and postoperative pneumonia (POP) and the feasibility of perioperative FeNO for predicting POP in surgical lung cancer patients.

Methods

Patients who were diagnosed with non-small-cell lung cancer (NSCLC) were prospectively analyzed, and the relationship between perioperative FeNO and POP was evaluated based on patients' basic characteristics and clinical data in the hospital.

Results

There were 218 patients enrolled in this study. Finally, 183 patients were involved in the study, with 19 of them in the POP group and 164 in the non-POP group. The POP group had significantly higher postoperative FeNO (median: 30.0 vs. 19.0 ppb, P < 0.001) as well as change in FeNO (median: 10.0 vs. 0.0 ppb, P < 0.001) before and after the surgery. For predicting POP based on the receiver operating characteristic (ROC) curve, a cutoff value of 25 ppb for postoperative FeNO (Youden's index: 0.515, sensitivity: 78.9%, and specificity: 72.6%) and 4 ppb for change in FeNO (Youden's index: 0.610, sensitivity: 84.2%, specificity: 76.8%) were selected. Furthermore, according to the bivariate regression analysis, FEV1/FVC (OR = 0.948, 95% CI: 0.899–0.999, P=0.048), POD1 FeNO (OR = 1.048, 95% CI: 1.019–1.077, P=0.001), and change in FeNO (OR = 1.087, 95% CI: 1.044–1.132, P < 0.001) were significantly associated with occurrence of POP.

Conclusions

This prospective study revealed that a high postoperative FeNO (>25 ppb), as well as an increased change in FeNO (>4 ppb), may have the potential in detecting the occurrence of POP in surgical lung cancer patients.

Telocytes reduce oxidative stress by downregulating DUOX2 expression in inflamed lungs of mice

Telocytes (TCs), a novel type of interstitial cells, have been found to participate in tissue protection and repair. In this study, we investigated the antioxidative effects of TCs in inflamed lungs of mice. Acute respiratory distress syndrome (ARDS) mice were used as models of inflamed lungs of mice. Gene sequencing was used to screen the differentially expressed miRNAs in TCs after lipopolysaccharide (LPS) stimulation. AntagomiR-146a-5p-pretreated TCs were first injected into mice, and antioxidant activity of TCs was estimated. TCs, RAW264.7 cells, and MLE-12 cells were collected for the detection of expressions of NOX1-4, DUOX1-2, SOD1-3, GPX1-2, CAT, Nrf2, miR-146a-5p, and miR-21a-3p after LPS stimulation. Silencing miRNAs were delivered to examine the involved signaling pathways. Oxidative stress was examined by measuring malondialdehyde (MDA) levels. We found that microRNA-146a-5p and microRNA-21a-3p were upregulated in TCs after LPS stimulation. ARDS mice that were preinfused with TCs had lower lung tissue injury scores, lung wet-dry ratios, white blood cell counts in alveolar lavage fluid and lower MDA concentrations in lung tissue. However, in antagomiR-146a-5p-pretreated ARDS mice, the infusion of TCs caused no corresponding changes. After LPS stimulation, DUOX2 and MDA concentrations were downregulated in TCs, while DUOX2 was restored by antagomiR-146a-5p in TCs. Dual-luciferase reporter assay confirmed that CREB1 was downregulated by miR-146a-5p, while DUOX2 was downregulated by CREB1, which was confirmed by treating TCs with a specific CREB1 inhibitor. This study demonstrates that LPS stimulation upregulates miR-146a-5p in TCs, which downregulates the CREB1/DUOX2 pathway, resulting in a decrease in oxidative stress in cultured TCs. TCs reduce LPS-induced oxidative stress by decreasing DUOX2 in inflamed lungs of mice.

Systematic review of diagnostic methods for acute respiratory distress syndrome

Rationale

Acute respiratory distress syndrome (ARDS) is currently diagnosed by the Berlin definition, which does not include a direct measure of pulmonary oedema, endothelial permeability or pulmonary inflammation. We hypothesised that biomarkers of these processes have good diagnostic accuracy for ARDS.

Methods

Medline and Scopus were searched for original diagnostic studies using minimally invasive testing. Primary outcome was the diagnostic accuracy per test and was categorised by control group. The methodological quality was assessed with QUADAS-2 tool. Biomarkers that had an area under the receiver operating characteristic curve (AUROCC) of >0.75 and were studied with minimal bias against an unselected control group were considered to be promising.

Results

Forty-four articles were included. The median AUROCC for all evaluated tests was 0.80 (25th to 75th percentile: 0.72–0.88). The type of control group influenced the diagnostic accuracy (p=0.0095). Higher risk of bias was associated with higher diagnostic accuracy (AUROCC 0.75 for low-bias, 0.77 for intermediate-bias and 0.84 for high-bias studies; p=0.0023). Club cell protein 16 and soluble receptor for advanced glycation end-products in plasma and two panels with biomarkers of oxidative stress in breath showed good diagnostic accuracy in low-bias studies that compared ARDS patients to an unselected intensive care unit (ICU) population.

Conclusion

This systematic review revealed only four diagnostic tests fulfilling stringent criteria for a promising biomarker in a low-bias setting. For implementation into the clinical setting, prospective studies in a general unselected ICU population with good methodological quality are needed.

Accuracy of diagnosis of acute respiratory distress syndrome (ARDS) is associated with risk of bias. There is a lack of validated diagnostic tests in an unbiased setting, emphasising the need for quality driven diagnostic research in ARDS.https://bit.ly/2GfPAvf

Adaptive support ventilation attenuates postpneumonectomy acute lung injury in a porcine model

OBJECTIVES

An optimal ventilation strategy that causes as little mechanical stress and inflammation as possible is critical for patients undergoing pneumonectomy. The aim of this study was to determine whether adaptive support ventilation (ASV) can provide protective ventilation to the remaining lung after pneumonectomy with minimal mechanical stress and less inflammation than volume-control ventilation (VCV).

METHODS

In this study, 15 pigs were randomly allocated to 3 groups (n = 5 for each group): the control group, the VCV group and the ASV group. After left pneumonectomy, the VCV group was treated with the volume-control set to 20 ml/kg, and the ASV group with the mode set to achieve 60% of the minute ventilation of 2 lungs.

RESULTS

The ASV group had lower alveolar strain than the VCV group. The ASV group exhibited less lung injury and greater alveolar fluid clearance than the VCV group (13.3% vs -17.8%; P ≤ 0.018). Ventilator-induced lung injury was associated with changes in the cytokine levels in the exhaled breath condensate, differential changes in plasma and changes in the cytokines in the bronchoalveolar lavage fluid. Expression of 3 microRNAs (miR449b-3p, P ≤ 0.001; miR451-5p, P = 0.027; and miR144-5p, P = 0.008) was increased in the VCV group compared with the ASV group.

CONCLUSIONS

The ASV mode was capable of supporting rapid, shallow breathing patterns to exert lung-protective effects in a porcine postpneumonectomy model. Further investigation of microRNAs as biomarkers of ventilator-induced lung injury is warranted.

Changes in the concentrations of mediators in exhaled breath condensate during cardiac valve replacement under cardiopulmonary bypass and their relations with postoperative acute respiratory distress syndrome

To investigate the changes in the concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and 8-iso-prostaglandin F2α (8-isoPGF2α) in exhaled breath condensate (EBC) in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB) and its relationship with postoperative acute respiratory distress syndrome (ARDS).A prospective, case-control study was performed on 55 patients undergoing elective cardiac valve replacement under cardiopulmonary bypass, between November 2017 and May 2019. According to the diagnosis of postoperative ARDS, the patients were divided into ARDS group and control group. We compared the clinical characteristics, outcomes, respiratory mechanics, oxygenation parameters, and mediators in the 2 groups immediately after tracheal intubation (T1), at the end of CPB (T2), and 2 hours (T3) and 6 hours (T4) after CPB, and calculated the receiver operating characteristic curve (ROC), sensitivity, and specificity of the corresponding mediators.ARDS occurred in 29 patients after CPB. The ARDS group exhibited prolonged postoperative ventilator support, time to extubation, length of stay in the ICU, and postoperative length of stay. The peak airway pressure (Ppeak) and plat airway pressure (Pplat) at T4 were higher in the ARDS group compared with the control group. The alveolar-arterial oxygen partial pressure [P(A-a)O2] and respiratory index (RI) were higher and PaO2/FiO2 was lower in the ARDS group at T2-4 compared with the control group. The levels of EBC and serum mediators in the ARDS group were significantly higher at T2-4 compared with those in the control group. All the mediators in EBC were correlated significantly with those in the serum in the ARDS group (r = 0.7314, 0.898, 0.8386, 0.792) and control group (r = 0.6093, 0.8524, r = 0.7828, r = 0.6575) (P < .001). Meanwhile, the area under the curve (AUC) of IL-8 in EBC was significantly lower at T2 and the AUC of IL-6 in EBC was significantly higher at T4 than in serum (P < .05). In addition, all of the mediators in EBC had a certain accuracy in diagnose of postoperative ARDS.EBC analysis could be used to predict the high incidence of ARDS after cardiac valve replacement under CPB.

Recruitment maneuver leads to increased expression of pro-inflammatory cytokines in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a disease with high morbidity and mortality rates. The recruitment maneuver (RM) is one of the interventions used for ARDS patients suffering from severe hypoxemia. RM works by opening the atelectatic lungs using high transpulmonary pressure. RM has therefore been widely used for many years in patients with ARDS. However, because of the high transpulmonary pressure used in this intervention, there are concerns about both biotrauma and hemodynamic instability. To assess the effects of RM in ARDS, we conducted a study using three groups of pigs (n = 6 in each group): group I (control), group II (ARDS), and group III (ARDS with RM). After measuring the baseline values, ARDS was induced by deactivating the surfactant with 5% Tweens lavage. For pigs of group III, the RM protocol used was positive end-expiratory pressure (PEEP) of 25 cmH₂O and peak pressure of 45 cmH₂O. Gas exchange, hemodynamics, the expression of cytokines in serum, bronchoalveolar lavage fluid (BALF), and exhaled breath condensates (EBCs) were measured. The baseline measurements taken were similar across the three groups, and no significant difference was noted. After the induction of ARDS, PaO₂ substantially decreased, while PaCO₂, alveolar-arterial O₂ gradient, pulmonary arterial pressure, lung water, level of cytokines in serum, EBCs, and BALF all increased. After RM, gas exchange and lung water level improved, but the level of cytokines in EBCs and BALF increased. Although RM led to an improvement in gas exchange, it may cause release of inflammatory cytokines in the EBCs and BALF.

Association between Early Acute Respiratory Distress Syndrome after Living-Donor Liver Transplantation and Perioperative Serum Biomarkers: The Role of Club Cell Protein 16

Background

Acute respiratory distress syndrome (ARDS) after living-donor liver transplantation (LDLT) is not uncommon, but it lacks the biomarkers for early detection. Club cell protein 16 (CC16), high-motility group box 1 protein (HMGB1), interleukin-1β (IL-1β), and IL-10 have been reported as relevant to the development of ARDS. However, they have not been investigated during LDLT.

Methods

Seventy-three consecutive recipients undergoing LDLT were enrolled and received the same perioperative care plan. Perioperative serum CC16, HMGB1, IL-1β, and IL-10 levels were measured at the pretransplant state, 30 minutes after reperfusion, postoperative day 1 (POD1), and POD3. ARDS was diagnosed according to the 2012 Berlin definition.

Results

Of the 73 recipients, 13 developed ARDS with significantly longer durations of mechanical ventilation and intensive care unit stay. Serum CC16 levels on POD1 increased significantly from the pretransplant state in the ARDS group but not in the non-ARDS group. Pretransplant serum CC16 levels were also higher in the ARDS group. The area under the receiver operating characteristic curves for POD1 serum CC16 levels used to discriminate ARDS was 0.803 (95% confidence interval: 0.679 to 0.895; p < 0.001). By comparison, HMGB1, IL-1β, and IL-10 were not associated with ARDS after LDLT.

Conclusion

The higher pretransplant serum CC16 level and its increased level on POD1 were associated with the development of early ARDS after LDLT. This trial is registered with NCT01936545, 27 August 2013.

Exhaled Breath Condensate: Pilot Study of the Method and Initial Experience in Healthy Subjects

Analysis of Exhaled breath condensate (EBC) is a re-discovered approach to monitoring the course of the disease and reduce invasive methods of patient investigation. However, the major disadvantage and shortcoming of the EBC is lack of reliable and reproducible standardization of the method. Despite many articles published on EBC, until now there is no clear consensus on whether the analysis of EBC can provide a clue to diagnosis of the diseases. The purpose of this paper is to investigate our own method, to search for possible standardization and to obtain our own initial experience. Thirty healthy volunteers provided the EBC, in which we monitored the density, pH, protein, chloride and urea concentration. Our results show that EBC pH is influenced by smoking, and urea concentrations are affected by the gender of subjects. Age of subjects does not play a role. The smallest coefficient of variation between individual volunteers is for density determination. Current limitations of EBC measurements are the low concentration of many biomarkers. Standardization needs to be specific for each individual biomarker, with focusing on optimal condensate collection. EBC analysis has a potential become diagnostic test, not only for lung diseases.

N-Acetylcysteine inhalation improves pulmonary function in patients received liver transplantation

Postoperative pulmonary complications (PPCs) following orthotopic liver transplantation (OLT) are associated with high morbidity and mortality rates. The effect of N-acetylcysteine (NAC) inhalation on the incidence of PPCs and the outcomes of patients undergoing OLT is unknown. This prospective randomized controlled clinical trial was conducted to investigate the effect of NAC inhalation during OLT on PPCs. Sixty patients were randomly assigned to the NAC group (n = 30) or the control group (n = 30) to receive inhaled NAC or sterilized water, respectively, for 30 min before surgery and 3 h after reperfusion. The incidence of early PPCs and outcomes including survival rate were assessed. Biomarkers including tumor necrosis factor (TNF)-α, interleukin (IL)-8, Clara cell secretory protein (CC16), intercellular adhesion molecule (ICAM)-1, and superoxide dismutase (SOD) were measured in exhaled breath condensate (EBC) at T1 (before surgery) and T2 (at the end of operation) as well as in serum at T1, T2, T3 (12 h after operation), and T4 (24 h after operation). A total of 42 patients (20 in the NAC group and 22 in the control group) were enrolled in the final analysis. Atomization inhaled NAC significantly reduced the incidence of PPCs after OLT. The levels of TNF-α, IL-8, CC16, and ICAM-1 in EBC were significantly lower, and SOD activity was higher, at T2 in the NAC group; similar data were found in serum at T2, T3, and T4. In summary, perioperative NAC inhalation may reduce the incidence of PPCs and improve patient outcomes after OLT.

Aerosolized prostacyclins for acute respiratory distress syndrome (ARDS)

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a critical condition that is associated with high mortality and morbidity. Aerosolized prostacyclin has been used to improve oxygenation despite the limited evidence available so far.This review was originally published in 2010 and updated in 2017.

OBJECTIVES

To assess the benefits and harms of aerosolized prostacyclin in adults and children with ARDS.

SEARCH METHODS

In this update, we searched CENTRAL (2017, Issue 4); MEDLINE (OvidSP), Embase (OvidSP), ISI BIOSIS Previews, ISI Web of Science, LILACS, CINAHL (EBSCOhost), and three trials registers. We handsearched the reference lists of the latest reviews, randomized and non-randomized trials, and editorials, and cross-checked them with our search of MEDLINE. We contacted the main authors of included studies to request any missed, unreported or ongoing studies. The search was run from inception to 5 May 2017.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs), irrespective of publication status, date of publication, blinding status, outcomes published or language. We contacted trial investigators and study authors to retrieve relevant and missing data.

DATA COLLECTION AND ANALYSIS

Three authors independently abstracted data and resolved any disagreements by discussion. Our primary outcome measure was all-cause mortality. We planned to perform subgroup and sensitivity analyses to assess the effect of aerosolized prostacyclin in adults and children, and on various clinical and physiological outcomes. We assessed the risk of bias through assessment of methodological trial components and the risk of random error through trial sequential analysis.

MAIN RESULTS

We included two RCTs with 81 participants.One RCT involved 14 critically ill children with ARDS (very low quality of evidence), and one RCT involved 67 critically ill adults (very low quality evidence).Only one RCT (paediatric trial) provided data on mortality and found no difference between intervention and control. However, this trial was eligible for meta-analysis due to a cross-over design.We assessed the benefits and harms of aerosolized prostacyclin. One RCT found no difference in improvement of partial pressure of oxygen in arterial blood/fraction of inspired oxygen (PaO₂/FiO₂) ratio (mean difference (MD) -25.35, 95% confidence interval (CI) -60.48 to 9.78; P = 0.16; 67 participants, very low quality evidence).There were no adverse events such as bleeding or organ dysfunction in any of the included trials. Due to the limited number of RCTs, we were unable to perform the prespecified subgroup and sensitivity analyses or trial sequential analysis.

AUTHORS' CONCLUSIONS

We are unable to tell from our results whether the intervention has an important effect on mortality because the results were too imprecise to rule out a small or no effect. Therefore, no current evidence supports or refutes the routine use of aerosolized prostacyclin for people with ARDS. There is an urgent need for more RCTs.

Oxidative stress and inflamatory plasma biomarkers in respiratory syncytial virus bronchiolitis

INTRODUCTION

Oxidative stress (OS) plays a crucial role in the pathogenesis of inflammatory lung diseases.

OBJECTIVES

(i) We determined whether acute bronchiolitis (AB) caused by respiratory syncytial virus (RSV) induced OS; (ii) assessed whether OS biomarkers correlated with the severity of RSV-AB; and (iii) studied whether the levels of interleukins are associated with OS biomarkers.

METHODS

We performed an observational study by comparing healthy infants (Group 1) with RSV-AB infants, classified as Group 2 (pulse oximetry (SpO₂ ) >93%), and Group 3 (SpO₂  ≤ 92%), which needed oxygen therapy. Blood samples were collected to determine the levels of lipid peroxidation (LPO) products (LPO), total glutathione (TG), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), interleukins (ILs) IL-10, IL-6, IL-8, interferon-gamma (IFNγ), tumour necrosis factor-alpha (TNFα) and macrophage inflammatory proteins (MIP α and MIP β).

RESULTS

Forty-six RSV-AB infants (47% needed oxygen therapy) and 27 healthy infants were included. The GSH/GSSG ratio was lower in RSV-AB infants than in Group 1 (P<0.001). GSSG and GPx were significantly higher in Group 3. GSSG predicted the need for oxygen therapy with an optimal cut-off point of 15 µM/g for haemoglobin. The GSH/GSSG ratio negatively correlated with IL-6 (P: 0.014), IL-8 (P: 0.014) and IL-10 (P: 0.033). Group 3 exhibited a direct correlation between GPx and IL-10 levels (P: 0.024) and between LPO and MIP β (P: 0.003).

CONCLUSIONS

RSV induced OS in AB. An increase in GSSG correlated with the disease severity in the infants. OS may contribute to the pathogenesis of RSV-AB.

Sampling and analyzing alveolar exhaled breath condensate in mechanically ventilated patients: a feasibility study

Recent studies in spontaneously breathing subjects indicate the possibility of obtaining the alveolar fraction of exhaled breath condensate (aEBC). In critically ill mechanically ventilated patients, in whom microbial colonization of the upper airways is constant, collection of aEBC could considerably add to the ability of monitoring alveolar inflammation. We designed this study to test the feasibility of collecting aEBC in mechanically ventilated critically ill patients through a dedicated apparatus, i.e. a CO2 valve combined with a condenser placed in the expiratory limb of the ventilator circuit. We also aimed to assess the adequacy of the samples obtained by measuring different markers of oxidative stress and inflammation. We enrolled 40 mechanically ventilated patients, 20 with and 20 without acute respiratory distress syndrome (ARDS). Measurements of respiratory mechanics, gas exchange and hemodynamics were obtained with a standard ventilator circuit after 30 min of aEBC collection and after inserting the dedicated collecting apparatus. Data showed that intrinsic positive end-expiratory pressure, peak and plateau pressure, static compliance and airway resistance (Raw) were similar before and after adding the collecting apparatus in both ARDS and controls. Similarly, gas exchange and hemodynamic variables did not change and 30 min collection provided a median aEBC volume of 2.100 and 2.300 ml for ARDS and controls, respectively. aEBC pH showed a trend toward a slight reduction in the ARDS group of patients, as opposed to controls (7.83 (7.62-8.03) versus 7.98 (7.87-8.12), respectively, p  =  0.055)). H2O2 was higher in patients with ARDS, compared to controls (0.09 (0.06-0.12) μM versus 0.03 (0.01-0.09) μM, p  =  0.043), while no difference was found in proteins content, 8-isoprostane, 4-hydroxy-2-nonhenal. In conclusion, we demonstrate, in patients receiving controlled mechanical ventilation, that aEBC collection is feasible without detrimental effects on ventilator functioning, respiratory mechanics and gas exchange. In addition, we show that the sample obtained is appropriate for compounds analysis.

SelW regulates inflammation-related cytokines in response to H2O2in Se-deficient chicken liver

Selenium (Se) deficiency-induced liver damage is related to oxidative stress, and the alternative transcription of cytokines has been linked to liver disease.