N-acetyl cysteine mitigates lung damage and inflammation after chlorine exposure in vivo and ex vivo

The objective of this study was to explore the effects of antioxidant treatments, specifically N-acetylcysteine (NAC) and N-acetylcysteine amide (NACA), in a mouse model of chlorine (Cl2)-induced lung injury. Additionally, the study aimed to investigate the utility of pig precision-cut lung slices (PCLS) as an ex vivo alternative for studying the short-term effects of Cl2 exposure and evaluating antioxidant treatments. The toxicological responses were analyzed in Cl2-exposed mice (inflammation, airway hyperresponsiveness (AHR)) and PCLS (viability, cytotoxicity, inflammatory mediators). Airways contractions were assessed using a small ventilator for mice and electric-field stimulation (EFS) for PCLS. Antioxidant treatments were administered to evaluate their effects. In Cl2-exposed mice, NAC treatment did not alleviate AHR, but it did reduce the number of neutrophils in bronchoalveolar lavage fluid and inflammatory mediators in lung tissue. In PCLS, exposure to Cl2 resulted in concentration-dependent toxicity, impairing the lung tissue's ability to respond to EFS-stimulation. NAC treatment increased viability, mitigated the toxic responses caused by Cl2 exposure, and maintained contractility comparable to unexposed controls. Interestingly, NACA did not provide any additional treatment effect beyond NAC in both models. In conclusion, the establishment of a pig model for Cl2-induced lung damage supports further investigation of NAC as a potential treatment. However, the lack of protective effects on AHR after NAC treatment in mice suggests that NAC alone may not be sufficient as a complete treatment for Cl2 injuries. Optimization of existing medications with a polypharmacy approach may be more successful in addressing the complex sequelae of Cl2-induced lung injury.

Do alternative tobacco products induce less adverse respiratory risk than cigarettes?

RATIONALE

Due to the relatively short existence of alternative tobacco products, gaps exist in our current understanding of their long-term respiratory health effects. We therefore undertook the first-ever side-by-side comparison of the impact of chronic inhalation of aerosols emitted from electronic cigarettes (EC) and heated tobacco products (HTP), and combustible cigarettes (CC) smoke.

OBJECTIVES

To evaluate the potential differential effects of alternative tobacco products on lung inflammatory responses and efficacy of vaccination in comparison to CC.

METHODS

Mice were exposed to emissions from EC, HTP, CC, or air for 8 weeks. BAL and lung tissue were analyzed for markers of inflammation, lung damage, and oxidative stress. Another group was exposed for 12 weeks and vaccinated and challenged with a bacterial respiratory infection. Antibody titers in BAL and sera and pulmonary bacterial clearance were assessed.

MAIN RESULTS

EC- and HTP-aerosols significantly augmented lung immune cell infiltrates equivalent to that achieved following CC-exposure. HTP and CC significantly increased neutrophil numbers compared to EC. All products augmented numbers of B cells, T cells, and pro-inflammatory IL17A+ T cells in the lungs. Decreased lung antioxidant activity and lung epithelial and endothelial damage was induced by all products. EC and HTP differentially augmented inflammatory cytokines/chemokines in the BAL. Generation of immunity following vaccination was impaired by EC and HTP but to a lesser extent than CC, with a CC > HTP > EC hierarchy of suppression of pulmonary bacterial clearance.

CONCLUSIONS

HTP and EC-aerosols induced a proinflammatory pulmonary microenvironment, lung damage, and suppressed efficacy of vaccination.

Research progress on the effects of gut microbiome on lung damage induced by particulate matter exposure

Air pollution is one of the top five causes of death in the world and has become a research hotspot. In the past, the health effects of particulate matter (PM), the main component of air pollutants, were mainly focused on the respiratory and cardiovascular systems. However, in recent years, the intestinal damage caused by PM and its relationship with gut microbiome (GM) homeostasis, thereby affecting the composition and function of GM and bringing disease burden to the host lung through different mechanisms, have attracted more and more attention. Therefore, this paper reviews the latest research progress in the effect of PM on GM-induced lung damage and its possible interaction pathways and explores the potential immune inflammatory mechanism with the gut-lung axis as the hub in order to understand the current research situation and existing problems, and to provide new ideas for further research on the relationship between PM pollution, GM, and lung damage.

From "crisis to recovery": A complete insight into the mechanisms of chlorine injury in the lung

Chlorine (Cl₂) gas is a toxic industrial chemical (TIC) that poses a hazard to human health following accidental and/or intentional (e.g. terrorist) release. By using a murine model of sub-lethal Cl₂ exposure we have examined the airway hyper responsiveness, cellular infiltrates, transcriptomic and proteomic responses of the lung. In the "crisis" phase at 2 h and 6 h there is a significant decreases in leukocytes within bronchoalveolar lavage fluid accompanied by an upregulation within the proteome of immune pathways ultimately resulting in neutrophil influx at 24 h. A flip towards "repair" in the transcriptome and proteome occurs at 24 h, neutrophil influx and an associated drop in the lung function persisting until 14 d post-exposure and subsequent "recovery" after 28 days. Collectively, this research provides new insights into the mechanisms of damage, early global responses and processes of repair induced in the lung following the inhalation of Cl₂.

Recent evidence for toxic effects of NH3 exposure on lung injury: Protective effects of L-selenomethionine

Ammonia (NH₃) is a common air pollutant, which poses a serious threat to farm animals. L-selenomethionine is organic selenium (Se), which can inhibit intracellular ROS generation, block ROS-dependent autophagy, promote mitochondrial energy metabolism, and enhance the body's immunity. Lung, as an important organ of the respiratory system, is highly susceptible to the toxic effects of NH₃. However, there were few studies on the mechanism of toxic effects of NH₃ on lung tissues. The aim of this study was to investigate the effect of NH₃ on the lungs in pigs and the alleviating effect of L-selenomethionine. Twenty-four Large White*Duroc*Min pigs were randomly assigned to 4 groups: control group, NH₃ group, Se group, and NH₃ +Se group. The results showed that exposure to NH₃ caused damage and inflammation in lung tissues and significantly increased blood NH₃ concentration. NH₃ induced changes of oxidative stress indexes (GSH, GSH-Px, SOD, MDA, Keap1, Nrf2, and HO-1) and expressions of energy metabolism related genes (HK1, HK2, PFK, PK, LDHA, and HIF-1α). Ultrastructure showed that mitochondrial damage and autophagosome increased significantly, and the expression levels of autophagy related genes (Beclin1, ATG5, ATG7, ATG10, and p62) changed. However, the addition of L-selenomethionine alleviated the above changes, but there was still a significant difference compared with the control group (P < 0.05). This finding can provide a new evidence for mitigation of NH₃ toxicity.

Blockchain Assisted Disease Identification of COVID-19 Patients with the Help of IDA-DNN Classifier

Globally, millions of people were affected by the Corona-virus disease-2019 (COVID-19) causing loads of deaths. Most COVID-19 affected people recover in a few spans of weeks. However, certain people even those with a milder variant of the disease persist in experiencing symptoms subsequent to their initial recuperation. Here, a novel Block-Chain (BC)-assisted optimized deep learning algorithm, explicitly improved dragonfly algorithm based Deep Neural Network (IDA-DNN), is proposed for detecting the different diseases of the COVID-19 patients. Initially, the input data of the COVID-19 recovered patients are gathered centered on their post symptoms and their data is amassed as a BC for rendering security to the patient's data. After that, the disease identification of the patient's data is performed with the aid of system training. The training includes '4' disparate datasets for data collection, and then, performs preprocessing, Feature Extraction (FE), Feature Reduction (FR), along with classification utilizing ID-DNN on the gathered inputted data. The IDA-DNN classifies '2' classes (presence of disease and absence of disease) for every type of data. The proposed method's outcomes are examined as well as contrasted with the other prevailing techniques to corroborate that the proposed IDA-DNN detects the COVID-19 more efficiently.

High throughput data-based, toxicity pathway-oriented development of a quantitative adverse outcome pathway network linking AHR activation to lung damages

The quantitative adverse outcome pathway (qAOP) is proposed to inform dose-responses at multiple biological levels for the purpose of toxicity prediction. So far, qAOP models concerning human health are scarce. Previously, we proposed 5 key molecular pathways that led aryl hydrogen receptor (AHR) activation to lung damages. The present study assembled an AOP network based on the gene expression signatures of these toxicity pathways, and validated the network using publicly available high throughput data combined with machine learning models. In addition, the AOP network was quantitatively evaluated with omics approaches and bioassays, using 16HBE-CYP1A1 cells exposed to benzo(a)pyrene (BaP), a prototypical AHR activator. Benchmark dose (BMD) analysis of transcriptomics revealed that AHR gene held the lowest BMD value, whereas AHR pathway held the lowest point of departure (PoD) compared to the other 4 pathways. Targeted bioassays were further performed to quantitatively understand the cellular responses, including ROS generation, DNA damage, interleukin-6 production, and extracellular matrix increase marked by collagen expression. Eventually, response-response relationships were plotted using nonlinear model fitting. The present study developed a highly reliable AOP model concerning human health, and validated as well as quantitatively evaluated it, and such a method is likely to be adoptable for risk assessment.

Repeated radon exposure induced lung damage via oxidative stress-mediated mitophagy in human bronchial epithelial cells and mice

This study aimed to investigate the potential molecular mechanism underlying radon-induced lung damage. Our results showed that long-term radon exposure induced mitochondrial damage and redox imbalance in BEAS-2B cells and a time-dependent lung pathological injury in mice. The activation of Nrf-2 and its down-stream antioxidants, and the gene expression of the indicated markers at different stages of autophagy were found to be induced with the increasing of radon exposure time. Changes in the gene expression of PINK-1, Parkin, and p62 induced by radon showed differences in mechanisms of mitophagy activation and profiles of autophagic flux between BEAS-2B cells and mice. Our findings not only demonstrated that long-term radon exposure induced damages to bronchial epithelial cells and the mice lung through increasing oxidative stress, decreasing mitochondrial function and activating mitophagy with different profiles of autophagic flux, but also revealed Nrf-2 as a central regulator of mitochondrial homeostasis and lung damage.

Cisplatin induces lung cell cilia disruption and lung damage via oxidative stress

BACKGROUND

Cisplatin (cis-diamminedichloroplatinum II) is widely used for the treatment of cancer, but its cellular toxicity, especially in the form of oxidative stress, limits its use in multiple organs including the lungs. As a cellular organelle, cilia play an important role in cellular function and can be damaged by oxidative stress. However, the effect of cisplatin-induced lung toxicity on cilia has not yet been defined. Herein, we investigated the association of cilia and oxidative stress with cisplatin-induced lung damage.

METHODS

Mice were administered with cisplatin. Some mice were treated with 2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito-TEMPO, a mitochondria-specific antioxidant) before the administration of cisplatin. Disruption of cilia was evaluated by the detection of ciliary proteins and fragments in the bronchoalveolar lavage fluid (BALF).

RESULTS

Cisplatin caused the thickening of interalveolar septa, infiltration of immune cells into the interalveolar septa, and increased protein concentration and total cell number in the BALF. Cisplatin also increased ciliary fragments and proteins in the BALF. In the lungs, cisplatin increased the production of hydrogen peroxide, lipid peroxidation, and apoptosis, while decreasing manganese superoxide dismutase, isocitrate dehydrogenase 2, and catalase expression. Treatment with Mito-TEMPO prevented cisplatin-induced lung damage, ciliary fragmentation, oxidative stress, and apoptosis.

CONCLUSION

By increasing oxidative stress in the lung, cisplatin induces lung cell damage, disruption of cilia, and release of disrupted cilia into the BALF. This suggests that cisplatin-induced lung damage can damage the cilia, manifesting as increased ciliary proteins in the BALF.

Germinal center-induced immunity is correlated with protection against SARS-CoV-2 reinfection but not lung damage

Germinal centers (GCs) elicit protective humoral immunity through a combination of antibody-secreting cells and memory B cells, following pathogen invasion or vaccination. However, the possibility of a GC response inducing protective immunity against reinfection following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains unknown. We found GC activity was consistent with seroconversion observed in recovered macaques and humans. Rechallenge with a different clade of virus resulted in significant reduction in replicating virus titers in respiratory tracts in macaques with high GC activity. However, diffuse alveolar damage and increased fibrotic tissue were observed in lungs of reinfected macaques. Our study highlights the importance of GCs developed during natural SARS-CoV-2 infection in managing viral loads in subsequent infections. However, their ability to alleviate lung damage remains to be determined. These results may improve understanding of SARS-CoV-2–induced immune responses, resulting in better coronavirus disease 2019 (COVID-19) diagnosis, treatment, and vaccine development.

High concentrations of ammonia induced cytotoxicity and bronchoconstriction in a precision-cut lung slices rat model

Exposure to high concentrations of ammonia (NH3) can cause life-threatening lung damages. The objective of this study was to establish a translational in vitro model for NH3-induced lung injury. Precision-cut lung slices (PCLS) from rats were exposed to NH3 and toxicological responses and cell viability were quantified by analysis of LDH, WST-1, inflammatory mediators (IL-1β, IL-6, CINC-1, MMP-9, RAGE and IL-18), and by microscopic evaluation of bronchoconstriction induced by electric-field-stimulation (EFS) or methacholine (MCh). Different treatment strategies were assessed to prevent or reverse the damages caused by NH3 using anti-inflammatory, anti-oxidant or neurologically active drugs. Exposure to NH3 caused a concentration-dependent increase in cytotoxicity (LDH/WST-1) and IL-1β release in PCLS medium. None of the treatments reduced cytotoxicity. Deposition of NH3 (24-59 mM) on untreated PCLS elicited an immediate concentration-dependent bronchoconstriction. Unlike MCh, the EFS method did not constrict the airways in PCLS at 5 h after NH3-exposure (47-59 mM). Atropine and TRP-channel antagonists blocked EFS-induced bronchoconstriction but these inhibitors could not block the immediate NH3-induced bronchoconstriction. In conclusion, NH3 exposure caused cytotoxic effects and lung damages in a concentration-dependent manner and this PCLS method offers a way to identify and test new concepts of medical treatments and biomarkers that may be of prognostic value.

Review on radiological evolution of COVID-19 pneumonia using computed tomography

BACKGROUND

Pneumonia is the main manifestation of coronavirus disease 2019 (COVID-19) infection. Chest computed tomography is recommended for the initial evaluation of the disease; this technique can also be helpful to monitor the disease progression and evaluate the therapeutic efficacy.

AIM

To review the currently available literature regarding the radiological follow-up of COVID-19-related lung alterations using the computed tomography scan, to describe the evidence about the dynamic evolution of COVID-19 pneumonia and verify the potential usefulness of the radiological follow-up.

METHODS

We used pertinent keywords on PubMed to select relevant studies; the articles we considered were published until October 30, 2020. Through this selection, 69 studies were identified, and 16 were finally included in the review.

RESULTS

Summarizing the included works’ findings, we identified well-defined stages in the short follow-up time frame. A radiographic deterioration reaching a peak roughly within the first 2 wk; after the peak, an absorption process and repairing signs are observed. At later radiological follow-up, with the limitation of little evidence available, the lesions usually did not recover completely.

CONCLUSION

Following computed tomography scan evolution over time could help physicians better understand the clinical impact of COVID-19 pneumonia and manage the possible sequelae; a longer follow-up is advisable to verify the complete resolution or the presence of long-term damage.

Intrabronchial application of extracellular histones shows no proinflammatory effects in swine in a translational pilot study

Objective

Extracellular histones have been identified as one molecular factor that can cause and sustain alveolar damage and were linked to high mortality rates in critically ill patients. In this pilot study, we wanted to validate the proinflammatory in vivo effects of local histone application in a prospective translational porcine model. This was combined with the evaluation of an experimental acute lung injury model using intrabronchial lipopolysaccharides, which has been published previously.

Results

The targeted application of histones was successful in all animals. Animals showed decreased oxygenation after instillation, but no differences could be detected between the sham and histone treatments. The histologic analyses and inflammatory responses indicated that there were no differences in tissue damage between the groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05704-7.

Aggressive alveolar recruitment in ARDS: More shadows than lights

Alveolar recruitment in acute respiratory distress syndrome (ARDS) is defined as the penetration of gas into previously unventilated areas or poorly ventilated areas. Alveolar recruitment during recruitment maneuvering (RM) depends on the duration of the maneuver, the recruitable lung tissue, and the balance between the recruitment of collapsed areas and over-insufflation of the ventilated areas. Alveolar recruitment is estimated using computed tomography of the lung and, at the patient bedside, through assessment of the recruited volume using pressure-volume curves and assessing lung morphology with pulmonary ultrasound and/or impedance tomography. The scientific evidence on RM in patients with ARDS remains subject to controversy. Randomized studies on ARDS have shown no benefit or have even reflected an increase in mortality. The routine use of RM is therefore not recommended.

β-Caryophyllene ameliorates the Mycoplasmal pneumonia through the inhibition of NF-κB signal transduction in mice

Background

Pneumonia is a frequent infectious disease that mainly affects the children and the global death rate is nearly 19% among children at the below 5 age. β-caryophyllene is an active compound, mainly occurs in the spices and it possesses immense biological activities.

Objective

This investigation deliberated to scrutinize the beneficial actions of β-caryophyllene against the M. pneumoniae induced pneumonia.

Methods

The pneumonia was stimulated to the BALB/c mice by infecting them with 100 µl of M. pneumonia for 2 days via nasal drops with the concomitant treatment with 20 mg/kg of β-caryophyllene. The total cells in the BALF of test mice were counted by using the Neuber chamber. The total protein and the pro-inflammatory cytokines status were examined by using the commercial ELISA kits. The PCR technique was used to measure the M. pneumoniae bacterial load. The NF-ƙB expression was investigated using western blotting. The lung tissues were analyzed microscopically.

Results

The β-caryophyllene notably diminished the total protein status, total cell count, and bacterial load in the pneumonia provoked mice. The marked reduction in the status of pro-inflammatory regulators was seen in the β-caryophyllene supplemented pneumonia mice. β-caryophyllene also down-regulated the expression of NF-ƙB thereby reduced the lung inflammation and tissue damages as seen in the result of histological analysis.

Conclusion

These findings were confirmed the therapeutic potential of β-caryophyllene against the M. pneumoniae-activated pneumonia in animals.

Lycopene and Caffeic Acid Phenethyl Ester Affect Caspase-3 Activity, but Do Not Alter the NO Pathway in Lung Tissue Damage Induced by Cisplatin

INTRODUCTION

Antioxidants such as lycopene (LCP) and caffeic acid phenethyl ester (CAPE) represent ideal molecules for the treatment of different reactive oxygen species (ROS) associated disorders. Cisplatin is a chemotherapeutic agent, causing an increase in ROS and DNA damage, with numerous side effects, which include lung toxicity. In the presents study, we evaluated and mutually compared the potential of LCP and CAPE in preventing cisplatin-induced rat lung damage.

METHODS

The study was done using pathohistological analysis and a panel of biochemical parameters that reflect lung oxidative tissue damage, inflammation, and apoptosis.

RESULTS

The obtained results suggest that cisplatin (10 mg/kg) causes significant disturbances in the lung tissue morphology, followed by an increase in lipid peroxidization and protein modification. Also, a pronounced inflammatory response and cell apoptosis cascade activation was noted. Both LCP and CAPE were able to mitigate the changes, to a different extent, in oxidative damage and apoptosis progression induced by cisplatin. However, they both had limited effect on inflammation since they only prevented an increase in myeloperoxidase activity but had not been able to prevent the NO generation.

CONCLUSION

It is hard to be exact in saying whether LCP or CAPE is better in preventing cis-platin-induced lung damage since they obviously possess different mechanisms of action.

Preclinical studies and the function of IL-17 cytokines in COPD

Chronic obstructive pulmonary disease (COPD) is among the leading causes of death worldwide and imposes a high economic burden to the health systems. COPD is characterized by chronic inflammation of the lung leading to airflow limitation, alveolar tissue destruction, and emphysema. Therefore, anti-inflammatory therapies for the treatment of COPD are of interest. In this review, we focus on the function of the IL-17 cytokines IL-17A and IL-17C, both known to mediate the recruitment of inflammatory cells, in the pathogenesis of COPD. We highlight that the expression of IL-17A and IL-17C is induced by pathogens frequently found in lungs of COPD patients and that targeting IL-17-signaling is an interesting option for the treatment of acute exacerbation of COPD.

Perspectives on mesenchymal stem/progenitor cells and their derivates as potential therapies for lung damage caused by COVID-19

The new coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which emerged in December 2019 in Wuhan, China, has reached worldwide pandemic proportions, causing coronavirus disease 2019 (COVID-19). The clinical manifestations of COVID-19 vary from an asymptomatic disease course to clinical symptoms of acute respiratory distress syndrome and severe pneumonia. The lungs are the primary organ affected by SARS-CoV-2, with a very slow turnover for renewal. SARS-CoV-2 enters the lungs via angiotensin-converting enzyme 2 receptors and induces an immune response with the accumulation of immunocompetent cells, causing a cytokine storm, which leads to target organ injury and subsequent dysfunction. To date, there is no effective antiviral therapy for COVID-19 patients, and therapeutic strategies are based on experience treating previously recognized coronaviruses. In search of new treatment modalities of COVID-19, cell-based therapy with mesenchymal stem cells (MSCs) and/or their secretome, such as soluble bioactive factors and extracellular vesicles, is considered supportive therapy for critically ill patients. Multipotent MSCs are able to differentiate into different types of cells of mesenchymal origin, including alveolar epithelial cells, lung epithelial cells, and vascular endothelial cells, which are severely damaged in the course of COVID-19 disease. Moreover, MSCs secrete a variety of bioactive factors that can be applied for respiratory tract regeneration in COVID-19 patients thanks to their trophic, anti-inflammatory, immunomodulatory, anti-apoptotic, pro-regenerative, and proangiogenic properties.

Efficacy and safety of aerosolized intra-tracheal dornase alfa administration in patients with SARS-CoV-2-induced acute respiratory distress syndrome (ARDS): a structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may trigger severe pneumonia in coronavirus disease of 2019 (COVID-19) patients through release of damage-associated molecular patterns (DAMPs) and recruitment of neutrophils in the lungs. Activated neutrophils induce inflammation and severe alveolar injury by releasing neutrophil extracellular traps (NETs). The backbones of many DAMPs and NETs are made of extracellular, cell-free DNA decorated with highly toxic compounds such as elastase, myeloperoxidase and citrullinated histones. Dornase alfa is a FDA-approved recombinant human DNAse 1 for the treatment of cystic fibrosis, which cleaves extracellular DNA and may break up cell-free DNA, loosening sticky mucus in the distal airways and reducing NETs-induced toxicity on alveolar pneumocytes. The COVIDornase trial intends to define the impact of aerosolized intra-tracheal dornase alfa administration on the severity and progression of acute respiratory distress syndrome (ARDS) in COVID-19 patients. This drug might make lung mucus thinner and looser, promoting improved clearance of secretions and reduce extracellular double-stranded DNA-induced hyperinflammation in alveoli, preventing further damage to the lungs.

TRIAL DESIGN

COVIDornase is a prospective, randomized, controlled, 2-arm (1:1 ratio), multicentric, open-label clinical trial.

PARTICIPANTS

The study will recruit mechanically ventilated patients hospitalized in the intensive care unit (ICU) in the recruiting centres (at the time of writing: The Rothschild foundation hospital in Paris, the Strasbourg university hospitals, and Metz-Thionville hospital) who have been diagnosed with COVID-19 and meet ARDS criteria.

INCLUSION CRITERIA

- Adult patient (age ≥ 18 years old); - Hospitalized in ICU; - With severe COVID-19 pneumonia and ARDS according to Berlin criteria (PaO2/FiO2 < 300 and PEEP > 5 cmH2O); - Intubated for less than 8 days; - With an anticipated duration of mechanical ventilation > 48 hours; - Carrier of an arterial catheter; - For whom 4 PaO2/FiO2 values over the preceding 24 hours are available; NON-INCLUSION CRITERIA: - Known hypersensitivity to dornase alfa or any of its excipients; - Pregnant or breastfeeding status; - Patient under legal protection.

INTERVENTION AND COMPARATOR

Intervention 1, Study group Dornase alfa (Pulmozyme®, Roche, Switzerland) will be administered by aerosol, at a dose of 2500 IU twice daily, 12 hours apart, for 7 consecutive days, using a vibrating mesh nebulizer (Aerogen Solo®, Aerogen, Ireland). The remainder of the management will be performed in accordance with good clinical practice, including mechanical ventilation (protective ventilation, PEEP > 5 cmH2O, tracheal balloon pressure check every 4 hours or automatic device, 30° head of the bed elevation, tidal volume 6-8mL/kg, plateau pressure < 30 cmH2O), neuromuscular blockers if necessary, prone position if PaO2/FiO2 < 150, early enteral nutrition, glycemic control and a sedation protocol based on the RASS score. Intervention 2, Comparator Patients will receive usual care in accordance with good practice (as detailed above), without aerosols.

MAIN OUTCOMES

The primary outcome is the occurrence of at least one grade improvement between D0 (inclusion) and D7 in the ARDS scale severity (Berlin criteria). For instance from "severe" to "moderate" or from "moderate" to "mild".

RANDOMISATION

All consecutive patients meeting the inclusion criteria will be randomised 1:1 using an eCRF-based, computer-generated randomisation table, either to the dornase alfa arm or to the control arm. An interim analysis will be performed after inclusion of 20 patients. Inclusions may be stopped at the interim analysis per data safety and monitoring board (DSMB) advice, if statistical analyses conclude on the futility or efficacy of the intervention or by other DSMB decision.

BLINDING (MASKING)

The participants and caregivers will not be blinded to study group assignment. Those assessing the outcomes will be blinded to study group assignment.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

Fifty patients will be randomized to each group, 100 patients in total.

TRIAL STATUS

Protocol version number 2, April 29th, 2020. Recruitment is ongoing. The trial started recruitment on the 21st April 2020. We estimate recruitment will finish August 21st 2020.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov on 21 April 2020, updated on 8 May 2020. Trial registration number is NCT04355364.

FULL PROTOCOL

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated. This Letter serves as a summary of the key elements of the full protocol.

Cytokine storm intervention in the early stages of COVID-19 pneumonia

Clinical intervention in patients with corona virus disease 2019 (COVID-19) has demonstrated a strong upregulation of cytokine production in patients who are critically ill with SARS-CoV2-induced pneumonia. In a retrospective study of 41 patients with COVID-19, most patients with SARS-CoV-2 infection developed mild symptoms, whereas some patients later developed aggravated disease symptoms, and eventually passed away because of multiple organ dysfunction syndrome (MODS), as a consequence of a severe cytokine storm. Guidelines for the diagnosis and treatment of SARS-CoV-2 infected pneumonia were first published January 30th, 2020; these guidelines recommended for the first time that cytokine monitoring should be applied in severely ill patients to reduce pneumonia related mortality. The cytokine storm observed in COVID-19 illness is also an important component of mortality in other viral diseases, including SARS, MERS and influenza. In view of the severe morbidity and mortality of COVID-19 pneumonia, we review the current understanding of treatment of human coronavirus infections from the perspective of a dysregulated cytokine and immune response.

Ellagic acid ameliorates lung damage in rats via modulating antioxidant activities, inhibitory effects on inflammatory mediators and apoptosis-inducing activities

Phytochemicals is considered one of the most effective and safe alternative therapy against oxidative linked lung diseases. Ellagic acid (EA), an important component of fruits, nuts, and vegetables, are partly responsible for their beneficial health effects against oxidation-related diseases. In the present study, we investigated the ameliorative effect of EA on lung damage induced by carbon tetrachloride (CCl₄) in Wistar male albino rats. Thirty-six male rats (n = 36, 8-week old) were divided into 4 groups, each with 9 rats. The groups were: Control group: received standard diet; EA group: administered with EA (10 mg/kg body weight, intraperitoneal); CCl₄ group: administered with CCl₄ (1.5 mg/kg body weight, intraperitoneal); EA+CCl₄ group: administered with EA and CCl₄. . The rats were decapitated at the end of experimental period of 8 weeks and the lung tissues were examined. CCl₄-induced rats showed elevation in the expressions of inflammatory proteins, nuclear factor kappa b (NF-κB), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α); and the indicator of lipid peroxidation, malondialdehyde (MDA). Intraperitoneal administration of EA significantly reduced the levels of these markers. EA administration increased the protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf-2) and enhanced the activity of glutathione (GSH) and catalase enzyme (CAT). In addition, EA administration increased the expression levels of the executioner protein of apoptosis, caspase-3, and decreasing pro-survival protein, B cell lymphoma-2 (Bcl-2). In conclusion, these results establishes the protective role of EA in the treatment of lung damage and that in the future, this may have the potential to be used as a medication for the prevention or attenuation of lung diseases. Graphical abstract.

Effects of crystalloid, hyper-oncotic albumin, and iso-oncotic albumin on lung and kidney damage in experimental acute lung injury

BACKGROUND

Conflicting data have reported beneficial effects of crystalloids, hyper-oncotic albumin (20%ALB), and iso-oncotic albumin (5%ALB) in critically ill patients. Although hyper-oncotic albumin may minimize lung injury, recent studies have shown that human albumin may lead to kidney damage proportional to albumin concentration. In this context, we compared the effects of Ringer's lactate (RL), 20%ALB, and 5%ALB, all titrated according to similar hemodynamic goals, on pulmonary function, lung and kidney histology, and molecular biology in experimental acute lung injury (ALI).

METHODS

Male Wistar rats received Escherichia coli lipopolysaccharide intratracheally (n = 24) to induce ALI. After 24 h, animals were anesthetized and randomly assigned to receive RL, 20%ALB, or 5%ALB (n = 6/group) to maintain hemodynamic stability (distensibility index of inferior vena cava < 25%, mean arterial pressure > 65 mmHg). Rats were then mechanically ventilated for 6 h. Six animals, which received neither ventilation nor fluids (NV), were used for molecular biology analyses.

RESULTS

The total fluid volume infused was higher in RL compared to 5%ALB and 20%ALB (median [interquartile range], 10.8[8.2-33.2] vs. 4.8[3.6-7.7] and 4.3[3.9-6.6] mL, respectively; p = 0.02 and p = 0.003). B-line counts on lung ultrasound (p < 0.0001 and p = 0.0002) and serum lactate levels (p = 0.01 and p = 0.01) were higher in RL than 5%ALB and 20%ALB. Diffuse alveolar damage score was lower in 5%ALB (10.5[8.5-12]) and 20%ALB (10.5[8.5-14]) than RL (16.5[12.5-20.5]) (p < 0.05 and p = 0.03, respectively), while acute kidney injury score was lower in 5%ALB (9.5[6.5-10]) than 20%ALB (18[15-28.5], p = 0.0006) and RL (16 [15-19], p = 0.04). In lung tissue, mRNA expression of interleukin (IL)-6 was higher in RL (59.1[10.4-129.3]) than in 5%ALB (27.0[7.8-49.7], p = 0.04) or 20%ALB (3.7[7.8-49.7], p = 0.03), and IL-6 protein levels were higher in RL than 5%ALB and 20%ALB (p = 0.026 and p = 0.021, respectively). In kidney tissue, mRNA expression and protein levels of kidney injury molecule (KIM)-1 were lower in 5%ALB than RL and 20%ALB, while nephronectin expression increased (p = 0.01 and p = 0.01), respectively.

CONCLUSIONS

In a rat model of ALI, both iso-oncotic and hyper-oncotic albumin solutions were associated with less lung injury compared to Ringer's lactate. However, hyper-oncotic albumin resulted in greater kidney damage than iso-oncotic albumin. This experimental study is a step towards future clinical designs.

Machine vision analysis on abnormal respiratory conditions of mice inhaling particles containing cadmium

Inhalable environmental toxicants can induce pulmonary malfunction resulting abnormal respiratory conditions. The traditional methods currently available to detect the respiratory condition of animals rely on differential pressure transducers and signal amplifiers. In comparison, current machine vision application requires little hardware. But it is unsuitable for respiratory condition tests of experimental animals reflecting respiratory toxicities of inhalable pollutants. In this study, we establish a new automatic method of machine vision analysis using a model that has mice inhaling aqueous aerosol with different concentrations of CdCl₂ (0, 1, 3, 5 mM 2 h/day) for 7 days as simulant occupational exposure of inhalable Cd and analyze respiratory conditions such as respiratory rate, rhythm index, drive index and exchange index. Additionally, the models with different degrees of lung damage in mice are further tested and verified by the concentrations of cadmium accumulated in the lungs and the analyses on pulmonary porosity, fibrosis and inflammation. Machine vision analysis can identify the abnormal respiratory conditions of mice. Respiratory rate and rhythm index increase after exposure to cadmium. In the individuals with mild lung damage, respiratory drive index and exchange index in treatment group are higher than that in the control group, and in individuals with severe lung damage, these indices are similar to that of the control group. These abnormal respiratory conditions related to variable lung damage in mice demonstrate that the respiration is synchronously influenced by inhalable Cd and respiratory compensation according to normal physiological regulation, suggesting the present method is effective.

Influenza-Mediated Lung Infection Models

Laboratory rodent influenza infection models have been and continue to be a critical tool for understanding virus-host interactions during infection. The incidence of seasonal influenza infections coupled with the need for novel therapeutics and universal vaccines highlights the need to uncover novel mechanisms of pathogenesis and protection. Mouse models are extremely useful for the evaluation of influenza vaccines and provide an invaluable tool to probe the immune response. This chapter describes the technique of intranasal inoculation of male C57BL/6J mice with an H1N1 strain of influenza (A/Puerto Rico/8/1934) and methods for assessing the optimum dose for infection, viral titers in lung tissue, and severity of disease.

[Pectus excavatum y carinatum en el síndrome de Marfan y síndromes similares: prevalencia e impacto clínico pulmonar y cardiovascular]

Introduction

Pectus excavatum (PE) and carinatum (PC) are common in Marfan syndrome (SM) and similar syndromes (SS). Patients can evolve without symptoms. In some there is depression, social adjustment disorders, pulmonary and cardiovascular symptoms in which there is controversy about their relationship with the structural damage of the thorax.

Objective

To assess the prevalence of the type of thoracic deformity in patients with MS and SS in a historical and current cohort and to analyze the clinical, pulmonary and cardiovascular impact.

Method

Prospective study. Subjects who met the Ghent criteria and who had a complete clinical record, an echocardiogram and/or magnetic resonance imaging, computed tomography and respiratory function tests were included.

Results

Of a total of 338 patients with MS and SS, 112 cases with thoracic deformity were detected, the prevalence of PE and PC in SM 13.6 and 12.4, respectively, was lower in SS. There is compression and displacement of lung and right cardiac cavities by PE and the correlation between the Haller Index and the increased PASP is 44 (p = 0.009).

Conclusions

The prevalence of PE and PC in SM and SS is high, which impacts on lung function and cardiovascular damage, requires corrective management of the thoracic deformity and not only implies for aesthetic purposes.

Ultra-low tidal volume ventilation-A novel and effective ventilation strategy during experimental cardiopulmonary resuscitation

BACKGROUND

The effects of different ventilation strategies during CPR on patient outcomes and lung physiology are still poorly understood. This study compares positive pressure ventilation (IPPV) to passive oxygenation (CPAP) and a novel ultra-low tidal volume ventilation (ULTVV) regimen in an experimental ventricular fibrillation animal model.

STUDY DESIGN

Prospective randomized controlled trial.

ANIMALS

30 male German landrace pigs (16-20 weeks).

METHODS

Ventricular fibrillation was induced in anesthetized and instrumented pigs and the animals were randomized into three groups. Mechanical CPR was initiated and ventilation was either provided by means of standard IPPV (RR: 10/min, Vt: 8-9 ml/kg, FiO2: 1,0, PEEP: 5 mbar), CPAP (O2-Flow: 10 l/min, PEEP: 5 mbar) or ULTVV (RR: 50/min, Vt: 2-3 ml/kg, FiO2: 1,0, PEEP: 5 mbar). Guideline-based advanced life support was applied for a maximum of 4 cycles and animals achieving ROSC were monitored for 6 h before terminating the experiment. Ventilation/perfusion ratios were performed via multiple inert gas elimination, blood gas analyses were taken hourly and extended cardiovascular measurements were collected constantly. Brain and lung tissue samples were taken and analysed for proinflammatory cytokine expression.

RESULTS

ULTVV provided sufficient oxygenation and ventilation during CPR while demanding significantly lower respiratory and intrathoracic pressures. V/Q mismatch was significantly decreased and lung injury was mitigated in surviving animals compared to IPPV and CPAP. Additionally, cerebral cytokine expression was dramatically reduced.

CONCLUSION

Ultra-low-volume ventilation during CPR in a porcine model is feasible and may provide lung-protective benefits as well as neurological outcome improvement due to lower inflammation. Our results warrant further studies and might eventually lead to new therapeutic options in the resuscitation setting.

[The anti-inflammatory effect of hesperetin on lung damage induced by paraquat in rats]

Objective: To investigate the anti-inflammatory effect of hesperetin (HSP) on lung damage induced by paraquat (PQ) in rats by detecting the levels of inflammatory makers in rat lung tissues. Methods: 140 Wistar male rats were randomly divided into negative control group, HSP control group, HSP control group, paraquat model group, pirfenidone (PDF) positive control group, and 100, 200, 400 mg/kg HSP treatment groups. All groups were exposed to 50mg/kg paraquat by oral gavage except for the negative control group and HSP control group. After 24 hours, the rats in each group were given drug intervention once daily. 10 rats were randomly sacrificed at 7th day and 28th day after exposure to paraquat respectively. 3 rats were randomly selected from them and HE, Masson staining were used to observe the pathological changes in the lungs of each group. Each group randomly selected 6 rats at two time points to detect the levels of TGF-β(1), TNF-α, IL-4, IL-10, IL-1β and IFN-γ in rat lung tissues. Results: Histopathological examination found that the lung injury were reduced in the rats of PDF positive control group and all HSP treatment groups. Compared with the negative control group, the levels of TGF-β1, IL-1β, TNF-α, IL-4, and IL-10 in rat lung tissues were significantly increased (P<0.05, P<0.01) after PQ exposure at two points in time, and there was no significant difference in the level of IFN-γ in lung tissues compared with the negative control group (P>0.05) . The levels of TGF-β1, IL-1β, IL-4, IL-10 and TNF-α in the lung tissues of rats on the 7th day in different dose treatment groups of HSP were reduced compared with those in the PQ model group with varying degrees (P<0.05, P<0.01) . The level of IFN-γ in lung tissues of rats were not significantly different from that of model group (P>0.05) . The levels of TGF-β(1) and TNF-α in lung tissue of rats on the 28th day in PDF positive control group and different dose treatment groups of HSP were reduced compared with those in the PQ model group with varying degrees (P<0.05, P<0.01). The levels of IFN-γ in the rat lung tissues were increased compared with those in the PQ model group (P<0.05). Besides, there were no significant in the levels of IL-1β, IL-4 and IL-10 in lung tissues compared with PQ model group (P>0.05). Conclusion: HSP can reduce lung damage induced by PQ in rats by inhibiting the release of inflammatory factors and promoting the secretion of anti-inflammatory factors.

Molecules of Damage-Associated Patterns in Bronchoalveolar Lavage Fluid and Serum in Chronic Obstructive Pulmonary Disease

Chronic exposure to detrimental environmental factors may induce immunogenic cell death of structural airway cells in chronic obstructive pulmonary disease (COPD). Damage-associated molecular patterns (DAMPs) is a family of heterogeneous molecules released from injured or dead cells, which activate innate and adaptive immune responses on binding to the pattern recognition receptors on cells. This study seeks to define the content of DAMPs in the bronchoalveolar lavage fluid (BALF) and serum of COPD patients, and the possible association of these molecules with clinical disease features. Thirty COPD in advanced disease stages were enrolled into the study. Pulmonary function tests, arterial blood gas content, 6-minute walk test, and BODE index were assessed. The content of DAMPs was estimated using the commercial sandwich-ELISA kits. We found differential alterations in the content of various DAMP molecules. In the main, BALF DAMPs positively associated with age, forced expiratory volume in one second (FEV1), and residual volume (RV); and inversely with PaO₂, residual volume/total lung capacity (RV/TLC) ratio, and the disease severity staging. In serum, DAMPS positively associated with the intensity of smoking and inversely with age, PaO₂, and TLC. In conclusion, DAMPs are present in both BALF and serum of COPD patients, which points to enhanced both local in the lung environment as well as systemic pro-inflammatory vein in this disease. These molecules appear involved with the lung damage and clinical variables featuring COPD. However, since the involvement of various DAMPs in COPD is variable, the exact role they play is by far unsettled and is open to further exploration.

Lung damage due to low-voltage electrical injury

Contact with high- or low-voltage electricity can cause injury. Low-voltage damage is more common and widespread, although there is little information on it in the literature. Exposure to an electrical current can effect every organ system in the body. The degree of damage is related to many factors, including the duration of exposure, type of current, and nature of the affected tissue. An unusual low-voltage electrical injury with a serious pulmonary lesion is presented, including the clinical intervention and imaging findings. We present a 20-year-old male electrician who sustained direct electrical damage to the pulmonary parenchyma, with no signs of chest wall damage, when exposed to a 380 V shock while working. Imaging demonstrated an electrical burn of the posterior right lower lobe. This case demonstrates that a low-voltage electric current can cause lung damage. A timely diagnosis is required for treatment.

Combinatorial treatment of idiopathic pulmonary fibrosis using nanoparticles with prostaglandin E and siRNA(s)

Inhalation delivery of prostaglandin E (PGE2) in combination with selected siRNA(s) was proposed for the efficient treatment of idiopathic pulmonary fibrosis (IPF). Nanostructured lipid carriers (NLC) were used as a delivery system for PGE2 with and without siRNAs targeted to MMP3, CCL12, and HIF1Alpha mRNAs. The model of IPF was developed in SKH1 mice by intratracheal administration of bleomycin at a dose of 1.5U/kg. Results showed that NLC-PGE2 in combination with three siRNAs delivered locally to the lungs by inhalation markedly reduced mouse body mass, substantially limited hydroxyproline content in the lungs and disturbances of the mRNAs and protein expression, restricted lung tissue damage and prevented animal mortality. Our data provide evidence that IPF can be effectively treated by inhalation of the NLC-PGE2 in combination with siRNAs delivered locally into the lungs. This effect could not be achieved by using NLC containing just PGE2 or siRNA(s) alone.

Pulmonary injury associated with radiation therapy - Assessment, complications and therapeutic targets

Pulmonary injury is more common in patients undergoing radiation therapy for lungs and other thoracic malignancies. Recently with the use of most-advanced technologies powerful doses of radiation can be delivered directly to tumor site with exquisite precision. The awareness of technical and clinical parameters that influence the chance of radiation induced lung injury is important to guide patient selection and toxicity minimization strategies. At the cellular level, radiation activates free radical production, leading to DNA damage, apoptosis, cell cycle changes, and reduced cell survival. Preclinical research shows the potential for therapies targeting transforming growth factor-β (TGF-B), Toll like receptor (TLRs), Tumour necrosis factor-alpha (TNF-alpha), Interferon gamma (IFN-γ) and so on that may restore lung function. At present Amifostine (WR-2721) is the only approved broad spectrum radioprotector in use for patients undergoing radiation therapy. Newer techniques also offer the opportunity to identify new biomarkers and new targets for interventions to prevent or ameliorate these late effects of lung damage.

Variable ventilation improves pulmonary function and reduces lung damage without increasing bacterial translocation in a rat model of experimental pneumonia

Background

Variable ventilation has been shown to improve pulmonary function and reduce lung damage in different models of acute respiratory distress syndrome. Nevertheless, variable ventilation has not been tested during pneumonia. Theoretically, periodic increases in tidal volume (V_T) and airway pressures might worsen the impairment of alveolar barrier function usually seen in pneumonia and could increase bacterial translocation into the bloodstream. We investigated the impact of variable ventilation on lung function and histologic damage, as well as markers of lung inflammation, epithelial and endothelial cell damage, and alveolar stress, and bacterial translocation in experimental pneumonia.

Methods

Thirty-two Wistar rats were randomly assigned to receive intratracheal of Pseudomonas aeruginosa (PA) or saline (SAL) (n = 16/group). After 24-h, animals were anesthetized and ventilated for 2 h with either conventional volume-controlled (VCV) or variable volume-controlled ventilation (VV), with mean V_T = 6 mL/kg, PEEP = 5cmH₂O, and FiO₂ = 0.4. During VV, tidal volume varied randomly with a coefficient of variation of 30% and a Gaussian distribution. Additional animals assigned to receive either PA or SAL (n = 8/group) were not ventilated (NV) to serve as controls.

Results

In both SAL and PA, VV improved oxygenation and lung elastance compared to VCV. In SAL, VV decreased interleukin (IL)-6 expression compared to VCV (median [interquartile range]: 1.3 [0.3–2.3] vs. 5.3 [3.6–7.0]; p = 0.02) and increased surfactant protein-D expression compared to NV (2.5 [1.9–3.5] vs. 1.2 [0.8–1.2]; p = 0.0005). In PA, compared to VCV, VV reduced perivascular edema (2.5 [2.0–3.75] vs. 6.0 [4.5–6.0]; p < 0.0001), septum neutrophils (2.0 [1.0–4.0] vs. 5.0 [3.3–6.0]; p = 0.0008), necrotizing vasculitis (3.0 [2.0–5.5] vs. 6.0 [6.0–6.0]; p = 0.0003), and ultrastructural lung damage scores (16 [14–17] vs. 24 [14–27], p < 0.0001). Blood colony-forming-unit (CFU) counts were comparable (7 [0–28] vs. 6 [0–26], p = 0.77). Compared to NV, VCV, but not VV, increased expression amphiregulin, IL-6, and cytokine-induced neutrophil chemoattractant (CINC)-1 (2.1 [1.6–2.5] vs. 0.9 [0.7–1.2], p = 0.025; 12.3 [7.9–22.0] vs. 0.8 [0.6–1.9], p = 0.006; and 4.4 [2.9–5.6] vs. 0.9 [0.8–1.4], p = 0.003, respectively). Angiopoietin-2 expression was lower in VV compared to NV animals (0.5 [0.3–0.8] vs. 1.3 [1.0–1.5], p = 0.01).

Conclusion

In this rat model of pneumonia, VV improved pulmonary function and reduced lung damage as compared to VCV, without increasing bacterial translocation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0476-7) contains supplementary material, which is available to authorized users.

Prediction of non-recovery from ventilator-demanding acute respiratory failure, ARDS and death using lung damage biomarkers: data from a 1200-patient critical care randomized trial

Background

It is unclear whether biomarkers of alveolar damage (surfactant protein D, SPD) or conductive airway damage (club cell secretory protein 16, CC16) measured early after intensive care admittance are associated with one-month clinical respiratory prognosis. If patients who do not recover respiratory function within one month can be identified early, future experimental lung interventions can be aimed toward this high-risk group. We aimed to determine, in a heterogenous critically ill population, whether baseline profound alveolar damage or conductive airway damage has clinical respiratory impact one month after intensive care admittance.

Methods

Biobank study of biomarkers of alveolar and conductive airway damage in intensive care patients was conducted. This was a sub-study of 758 intubated patients from a 1200-patient randomized trial. We split the cohort into a “learning cohort” and “validating cohort” based on geographical criteria: northern sites (learning) and southern sites (validating).

Results

Baseline SPD above the 85th percentile in the “learning cohort” predicted low chance of successful weaning from ventilator within 28 days (adjusted hazard ratio 0.6 [95% CI 0.4–0.9], p = 0.005); this was confirmed in the validating cohort. CC16 did not predict the endpoint. The absolute risk of not being successfully weaned within the first month was 48/106 (45.3%) vs. 175/652 (26.8%), p < 0.0001 (high SPD vs. low SPD). The chance of being “alive and without ventilator ≥20 days within the first month” was lower among patients with high SPD (adjusted OR 0.2 [95% CI 0.2–0.4], p < 0.0001), confirmed in the validating cohort, and the risk of ARDS was higher among patients with high SPD (adjusted OR 3.4 [95% CI 1.0–11.4], p = 0.04)—also confirmed in the validating cohort.

Conclusion

Early profound alveolar damage in intubated patients can be identified by SPD blood measurement at intensive care admission, and high SPD level is a strong independent predictor that the patient suffers from ARDS and will not recover independent respiratory function within one month. This knowledge can be used to improve diagnostic and prognostic models and to identify the patients who most likely will benefit from experimental interventions aiming to preserve alveolar tissue and therefore respiratory function.

Trial registration This is a sub-study to the Procalcitonin And Survival Study (PASS), Clinicaltrials.gov ID: NCT00271752, first registered January 1, 2006

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0212-y) contains supplementary material, which is available to authorized users.

Surfactant protein B: From biochemistry to its potential role as diagnostic and prognostic marker in heart failure

Growing interest raised on circulating biomarkers of structural alveolar-capillary unit damage and very recent data support surfactant protein type B (SP-B) as the most promising candidate in this setting. With respect to other proteins proposed as possible markers of lung damage, SP-B has some unique qualities: it is critical for the assembly of pulmonary surfactant, making its lack incompatible with life; it has no other known site of synthesis except alveolar epithelial cells different from other surfactant proteins; and, it undergoes a proteolytic processing in a pulmonary-cell-specific manner. In the recent years circulating SP-B isoforms, mature or immature, have been demonstrated to be detectable in the circulation depending on the magnitude of the damage of alveolar capillary membrane. In the present review, we summarize the recent knowledge on SP-B regulation, function and we discuss its potential role as reliable biological marker of alveolar capillary membrane (dys)function in the context of heart failure.

CD11d integrin blockade reduces the systemic inflammatory response syndrome after traumatic brain injury in rats

Traumatic CNS injury triggers a systemic inflammatory response syndrome (SIRS), in which circulating inflammatory cells invade body organs causing local inflammation and tissue damage. We have shown that the SIRS caused by spinal cord injury is greatly reduced by acute intravenous treatment with an antibody against the CD11d subunit of the CD11d/CD18 integrin expressed by neutrophils and monocyte/macrophages, a treatment that reduces their efflux from the circulation. Traumatic brain injury (TBI) is a frequently occurring injury after motor vehicle accidents, sporting and military injuries, and falls. Our studies have shown that the anti-CD11d treatment diminishes brain inflammation and oxidative injury after moderate or mild TBI, improving neurological outcomes. Accordingly, we examined the impact of this treatment on the SIRS triggered by TBI. The anti-CD11d treatment was given at 2h after a single moderate (2.5-3.0 atm) or 2 and 24h after each of three consecutive mild (1.0-1.5 atm) fluid percussion TBIs. Sham-injured, saline-treated rats served as controls. At 24h, 72 h, and 4 or 8 weeks after the single TBI and after the third of three TBIs, lungs of rats were examined histochemically, immunocytochemically and biochemically for downstream effects of SIRS including inflammation, tissue damage and expression of oxidative enzymes. Lung sections revealed that both the single moderate and repeated mild TBI caused alveolar disruption, thickening of inter-alveolar tissue, hemorrhage into the parenchyma and increased density of intra-and peri-alveolar macrophages. The anti-CD11d treatment decreased the intrapulmonary influx of neutrophils and the density of activated macrophages and the activity of myeloperoxidase after these TBIs. Moreover, Western blotting studies showed that the treatment decreased lung protein levels of oxidative enzymes gp91(phox), inducible nitric oxide synthase and cyclooxygenase-2, as well as the apoptotic pathway enzyme caspase-3 and levels of 4-hydroxynonenal-bound proteins (an indicator of lipid peroxidation). Decreased expression of the cytoprotective transcription factor Nrf2 reflected decreased lung oxidative stress. Anti-CD11d treatment also diminished the lung concentration of free radicals and tissue aldehydes. In conclusion, the substantial lung component of the SIRS after single or repeated TBIs is significantly decreased by a simple, minimally invasive and short-lasting anti-inflammatory treatment.

The xanthine oxidase inhibitor Febuxostat reduces tissue uric acid content and inhibits injury-induced inflammation in the liver and lung

Necrotic cell death in vivo induces a robust neutrophilic inflammatory response and the resulting inflammation can cause further tissue damage and disease. Dying cells induce this inflammation by releasing pro-inflammatory intracellular components, one of which is uric acid. Cells contain high levels of intracellular uric acid, which is produced when purines are oxidized by the enzyme xanthine oxidase. Here we test whether a non-nucleoside xanthine oxidase inhibitor, Febuxostat (FBX), can reduce intracellular uric acid levels and inhibit cell death-induced inflammation in two different murine tissue injury models; acid-induced acute lung injury and acetaminophen liver injury. Infiltration of inflammatory cells induced by acid injection into lungs or peritoneal administration of acetaminophen was evaluated by quantification with flow cytometry and tissue myeloperoxidase activity in the presence or absence of FBX treatment. Uric acid levels in serum and tissue were measured before giving the stimuli and during inflammation. The impact of FBX treatment on the peritoneal inflammation caused by the microbial stimulus, zymosan, was also analyzed to see whether FBX had a broad anti-inflammatory effect. We found that FBX reduced uric acid levels in acid-injured lung tissue and inhibited acute pulmonary inflammation triggered by lung injury. Similarly, FBX reduced uric acid levels in the liver and inhibited inflammation in response to acetaminophen-induced hepatic injury. In contrast, FBX did not reduce inflammation to zymosan, and therefore is not acting as a general anti-inflammatory agent. These results point to the potential of using agents like FBX to treat cell death-induced inflammation.