Neutrophil Extracellular Traps in Respiratory Disease: guided anti-microbial traps or toxic webs?

Neutrophil recruitment to the airways and lungs is a major hallmark of many respiratory diseases. One of the more recently discovered unique innate immune effector mechanisms of neutrophils is the formation of neutrophil extracellular traps (NETs), consisting of an extracellular network of DNA fibers studded with nuclear and granule proteins. Although in the respiratory system NETs contribute to capture and inactivation of bacteria, fungi and viruses, there is a delicate 'balance' between aid and damage to the host. Accumulating evidence now suggests that NETs can have direct cytotoxic effects to lung epithelial and endothelial cells and can contribute to airway obstruction. As such, NETs may play an important role in the pathogenesis of respiratory diseases. The purpose of this review is to give an up-to-date overview of the current status of NETs in respiratory diseases. We examine both experimental and clinical data concerning the role of NETs in host defence as well as immunopathology, with special attention paid to the literature relevant for the paediatric pulmonology community. Finally, we discuss future treatment strategies that may target the formation of NETs in the airways and lungs.

Alcohol and the Lung

Among the many organ systems affected by harmful alcohol use, the lungs are particularly susceptible to infections and injury. The mechanisms responsible for rendering people with alcohol use disorder (AUD) vulnerable to lung damage include alterations in host defenses of the upper and lower airways, disruption of alveolar epithelial barrier integrity, and alveolar macrophage immune dysfunction. Collectively, these derangements encompass what has been termed the "alcoholic lung" phenotype. Alcohol-related reductions in antioxidant levels also may contribute to lung disease in people with underlying AUD. In addition, researchers have identified several regulatory molecules that may play crucial roles in the alcohol-induced disease processes. Although there currently are no approved therapies to combat the detrimental effects of chronic alcohol consumption on the respiratory system, these molecules may be potential therapeutic targets to guide future investigation.

Mainstream capnography system for nonintubated children in the postanesthesia care unit: Performance with changing flow rates, and a comparison to side stream capnography

INTRODUCTION

Monitoring of exhaled carbon dioxide (CO₂ ) in nonintubated patients is challenging. We compared the precision of a mainstream mask capnography to side stream sampling nasal cannula capnography. In addition, we compared the effect of gas flow rates on the measured exhaled CO₂ between mainstream mask and side stream nasal cannula capnography.

METHODS

A mainstream mask capnography system (cap-ONE) was tested. Children (weight of 7-40 kg, ASA 1-2) following anesthesia for minor procedures were assigned randomly to side stream or mainstream sampling groups. The side stream group wore a nasal cannula with CO₂ side port (NC). In the postanesthesia care unit, O₂ flow was started at 5 l·min^-1 , reduced to 2 and then 0.25 l·min^-1 every 3 min. Capnogram analysis measuring heights of all the waveforms was performed for continuous 120 s from the end of recording at each O₂ flow rate for each group.

RESULTS

Fifty-eight children were enrolled and 39 were analyzed (18 side stream NC and 21 mainstream mask). There were two mouth breathing children excluded from study in side stream NC group due to failure to capture measurable CO₂ waveforms. Peak CO₂ values measured by mainstream mask system were normally (Gaussian) distributed with smaller standard deviation (sd) at each O₂ flow than were those measured by side stream NC system which demonstrated irregular distributions with larger sd. Peak CO₂ values measurement was less affected by a change in flow rate in mainstream mask group than in side stream NC group (P = 0.04 in 5-0.25 l·min^-1 O₂ flow change).

CONCLUSION

A new mainstream mask system (cap-ONE) performed with greater precision than side stream NC monitoring regardless of mouth breathing. Measurement of peak CO₂ values by mainstream mask system showed normal distribution with smaller standard deviation (sd) and was less affected by O₂ flow change in predictable fashion.

[Study on cytotoxicity of respiratory system exposed to fine particulate matter by real time cell analyze and Alamar Blue]

OBJECTIVE

To detect the cytotoxicity of fine particulate matter treated on human bronchial epithelial cells( BEAS-2B) and human embryonic lung fibroblasts( MRC-5) by using the method of real time cell analyze( RTCA) and Alamar Blue.

METHODS

Seed the BEAS-2B cells and MRC-5 cells in the 16-well plates for RTCA analyzer and commonly 96-well plates respectively. After 24 hours, the BEAS-2B cells and the MRC-5 cells were treated by the fine particulate matter respectively in different doses( 2500, 1250, 625, 312. 5, 156. 25 and 78. 125 μg / m L). Calculating the IC50 values which determined by the two methods on different times( 3, 12, 24, 36 and 48 h). Using paired t test by SPSS 16. 0 analyse the IC50 values from two methods and estimate the correlation.

RESULTS

There was correlation between the two methods, but there was no obvious difference between the two results by RTCA and Alamar Blue.

CONCLUSION

There is certain cytotoxicity of fine particulate matter. At the same time, the RTCA real-time monitoring technology can be used on determination of cytotoxicity in vitro.

Differential proteomic analysis of respiratory failure in peripheral blood mononuclear cells using iTRAQ technology

Respiratory failure (RF) is a state in which the respiratory system fails by its gas exchange functions. Failure of the lung, which is caused by all types of lung diseases, leads to hypoxaemia with type I respiratory failure. Failure of the pump leads to hypercapnia or type II respiratory failure. Using isobaric tags for relative and absolute quantification (iTRAQ) technology to identify and quantify the total proteins in peripheral blood mononuclear cells (PBMCs) of RF patients and identify the differentially expressed proteome. The present study analyzed the total proteins in the PBMCs of RF patients and healthy controls using the eight-plex iTRAQ added with strong cation-exchange chromatography and liquid chromatography coupled with tandem mass spectrometry. The differentially expressed proteins were identified by MASCOT. A total of 4,795 differentially expressed proteins were identified, and 403 proteins were upregulated and 421 were downregulated. Among them, 4 proteins were significantly differentially expressed, which were upregulated KIAA1520 protein and γ fibrinogen type B (AA at 202) and downregulated chain A, crystal structure of recombinant human platelet factor 4 and myosin regulatory light polypeptide 9. iTRAQ technology is suitable for identifying and quantifying the proteome in the PBMCs of RF patients. The differentially expressed proteins of RF patients have been identified in the present study, and further research of the molecular mechanism of the differentially expressed proteins is required to clarify the pathogenesis and identify novel biomarkers of RF.

The impact of PM2.5 on the human respiratory system

Recently, many researchers paid more attentions to the association between air pollution and respiratory system disease. In the past few years, levels of smog have increased throughout China resulting in the deterioration of air quality, raising worldwide concerns. PM2.5 (particles less than 2.5 micrometers in diameter) can penetrate deeply into the lung, irritate and corrode the alveolar wall, and consequently impair lung function. Hence it is important to investigate the impact of PM2.5 on the respiratory system and then to help China combat the current air pollution problems. In this review, we will discuss PM2.5 damage on human respiratory system from epidemiological, experimental and mechanism studies. At last, we recommend to the population to limit exposure to air pollution and call to the authorities to create an index of pollution related to health.

A Comparative Review of Animal Models of Middle East Respiratory Syndrome Coronavirus Infection

Middle East respiratory syndrome coronavirus (MERS-CoV) was initially isolated from a Saudi Arabian man with fatal pneumonia. Since the original case in 2012, MERS-CoV infections have been reported in >1500 humans, and the case fatality rate is currently 35%. This lineage C betacoronavirus has been reported to cause a wide range of disease severity in humans, ranging from asymptomatic to progressive fatal pneumonia that may be accompanied by renal or multiorgan failure. Although the clinical presentation of human MERS-CoV infection has been documented, many facets of this emerging disease are still unknown and could be studied with animal models. Several animal models of MERS-CoV have been developed, including New Zealand white rabbits, transduced or transgenic mice that express human dipeptidyl peptidase 4, rhesus macaques, and common marmosets. This review provides an overview of the current state of knowledge on human MERS-CoV infections, the probable origin of MERS-CoV, and the available animal models of MERS-CoV infection. Evaluation of the benefits and limitations of these models will aid in appropriate model selection for studying viral pathogenesis and transmission, as well as for testing vaccines and antivirals against MERS-CoV.

The impact of PM2.5 on the human respiratory system

Recently, many researchers paid more attentions to the association between air pollution and respiratory system disease. In the past few years, levels of smog have increased throughout China resulting in the deterioration of air quality, raising worldwide concerns. PM2.5 (particles less than 2.5 micrometers in diameter) can penetrate deeply into the lung, irritate and corrode the alveolar wall, and consequently impair lung function. Hence it is important to investigate the impact of PM2.5 on the respiratory system and then to help China combat the current air pollution problems. In this review, we will discuss PM2.5 damage on human respiratory system from epidemiological, experimental and mechanism studies. At last, we recommend to the population to limit exposure to air pollution and call to the authorities to create an index of pollution related to health.

Mesodermal lineages in the developing respiratory system

The life-sustaining air-blood interface of the respiratory system requires the exquisite integration of the epithelial lining with the mesenchymal capillary network, all supported by elastic smooth muscle and rigid cartilage keeping the expandable airways open. These intimate tissue interactions originate in the early embryo, where bidirectional paracrine signaling between the endoderm epithelium and adjacent mesoderm orchestrates lung and trachea development and controls the stereotypical branching morphogenesis. Although much attention has focused on how these interactions impact the differentiation of the respiratory epithelium, relatively less is known about the patterning and differentiation of the mesenchyme. Endothelial cells, smooth muscle cells, and chondrocytes together with other types of mesenchymal cells are essential components of a functional respiratory system, and malformation of these cells can lead to various congenital defects. In this review, we summarize the current understanding of mesenchymal development in the fetal trachea and lung, focusing on recent findings from animal models that have begun to shed light on the poorly understood respiratory mesenchyme lineages.

The Evolving Mcart Multimodal Imaging Core: Establishing a Protocol for Computed Tomography and Echocardiography in the Rhesus Macaque to Perform Longitudinal Analysis of Radiation-Induced Organ Injury

Computed Tomography (CT) and Echocardiography (EC) are two imaging modalities that produce critical longitudinal data that can be analyzed for radiation-induced organ-specific injury to the lung and heart. The Medical Countermeasures Against Radiological Threats (MCART) consortium has a well established animal model research platform that includes nonhuman primate (NHP) models of the acute radiation syndrome and the delayed effects of acute radiation exposure. These models call for a definition of the latency, incidence, severity, duration, and resolution of different organ-specific radiation-induced subsyndromes. The pulmonary subsyndromes and cardiac effects are a pair of interdependent syndromes impacted by exposure to potentially lethal doses of radiation. Establishing a connection between these will reveal important information about their interaction and progression of injury and recovery. Herein, the authors demonstrate the use of CT and EC data in the rhesus macaque models to define delayed organ injury, thereby establishing: a) consistent and reliable methodology to assess radiation-induced damage to the lung and heart; b) an extensive database in normal age-matched NHP for key primary and secondary endpoints; c) identified problematic variables in imaging techniques and proposed solutions to maintain data integrity; and d) initiated longitudinal analysis of potentially lethal radiation-induced damage to the lung and heart.

A MALDI-MSI Approach to the Characterization of Radiation-Induced Lung Injury and Medical Countermeasure Development

Radiation-induced lung injury is highly complex and characterized by multiple pathologies, which occur over time and sporadically throughout the lung. This complexity makes biomarker investigations and medical countermeasure screenings challenging. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has the ability to resolve differences spatially in molecular profiles within the lung following radiation exposure and can aid in biomarker identification and pharmaceutical efficacy investigations. MALDI-MSI was applied to the investigation of a whole-thorax lung irradiation model in non-human primates (NHP) for lipidomic analysis and medical countermeasure distribution.

Copper oxide nanoparticles aggravate airway inflammation and mucus production in asthmatic mice via MAPK signaling

Copper oxide nanoparticles (CuONPs), metal oxide nanoparticles were used in multiple applications including wood preservation, antimicrobial textiles, catalysts for carbon monoxide oxidation and heat transfer fluid in machines. We investigated the effects of CuONPs on the respiratory system in Balb/c mice. In addition, to investigate the effects of CuONPs on asthma development, we used a murine model of ovalbumin (OVA)-induced asthma. CuONPs markedly increased airway hyper-responsiveness (AHR), inflammatory cell counts, proinflammatory cytokines and reactive oxygen species (ROS). CuONPs induced airway inflammation and mucus secretion with increases in phosphorylation of the MAPKs (Erk, JNK and p38). In the OVA-induced asthma model, CuONPs aggravated the increased AHR, inflammatory cell count, proinflammatory cytokines, ROS and immunoglobulin E induced by OVA exposure. In addition, CuONPs markedly increased inflammatory cell infiltration into the lung and mucus secretions, and MAPK phosphorylation was elevated compared to OVA-induced asthmatic mice. Taken together, CuONPs exhibited toxicity on the respiratory system, which was associated with the MAPK phosphorylation. In addition, CuONPs exposure aggravated the development of asthma. We conclude that CuONPs exposure has a potential toxicity in humans with respiratory disease.

Anatomy and physiology of respiratory system relevant to anaesthesia

Clinical application of anatomical and physiological knowledge of respiratory system improves patient's safety during anaesthesia. It also optimises patient's ventilatory condition and airway patency. Such knowledge has influence on airway management, lung isolation during anaesthesia, management of cases with respiratory disorders, respiratory endoluminal procedures and optimising ventilator strategies in the perioperative period. Understanding of ventilation, perfusion and their relation with each other is important for understanding respiratory physiology. Ventilation to perfusion ratio alters with anaesthesia, body position and with one-lung anaesthesia. Hypoxic pulmonary vasoconstriction, an important safety mechanism, is inhibited by majority of the anaesthetic drugs. Ventilation perfusion mismatch leads to reduced arterial oxygen concentration mainly because of early closure of airway, thus leading to decreased ventilation and atelectasis during anaesthesia. Various anaesthetic drugs alter neuronal control of the breathing and bronchomotor tone.

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice.

Inappropriate antibiotic prescription for respiratory tract indications: most prominent in adult patients

BACKGROUND

Numerous studies suggest overprescribing of antibiotics for respiratory tract indications (RTIs), without really authenticating inappropriate prescription; the strict criteria of guideline recommendations were not taken into account as information on specific diagnoses, patient characteristics and disease severity was not available.

OBJECTIVE

The aim of this study is to quantify and qualify inappropriate antibiotic prescribing for RTIs.

METHODS

This is an observational study of the (antibiotic) management of patients with RTIs, using a detailed registration of RTI consultations by general practitioners (GPs). Consultations of which all necessary information was available were benchmarked to the prescribing guidelines for acute otitis media (AOM), acute sore throat, rhinosinusitis or acute cough. Levels of overprescribing for these indications and factors associated with overprescribing were determined.

RESULTS

The overall antibiotic prescribing rate was 38%. Of these prescriptions, 46% were not indicated by the guidelines. Relative overprescribing was highest for throat (including tonsillitis) and lowest for ear consultations (including AOM). Absolute overprescribing was highest for lower RTIs (including bronchitis). Overprescribing was highest for patients between 18 and 65 years of age, when GPs felt patients' pressure for an antibiotic treatment, for patients presenting with fever and with complaints longer than 1 week. Underprescribing was observed in <4% of the consultations without a prescription.

CONCLUSION

Awareness of indications and patient groups provoking antibiotic overprescribing can help in the development of targeted strategies to improve GPs' prescribing routines for RTIs.

Kenny Caffey syndrome with severe respiratory and gastrointestinal involvement: expanding the clinical phenotype

Kenny Caffey syndrome (KCS) is a rare syndrome reported almost exclusively in Middle Eastern populations. It is characterized by severe growth retardation-short stature, dysmorphic features, episodic hypocalcaemia, hypoparathyroidism, seizures, and medullary stenosis of long bones with thickened cortices. We report a 10-year-old boy with KCS with an unusually severe respiratory and gastrointestinal system involvement-features not previously described in the literature. He had severe psychomotor retardation and regressed developmentally from walking unaided to sitting with support. MRI brain showed bilateral hippocampal sclerosis, marked supra-tentorial volume loss and numerous calcifications. A 12 bp deletion of exon 2 of tubulin-specific chaperone E (TBCE) gene was identified and the diagnosis of KCS was confirmed. Hypercarbia following a sleep study warranted nocturnal continuous positive airway pressure (CPAP) when aged 6. When boy aged 8, persistent hypercarbia with increasing oxygen requirement and increased frequency and severity of lower respiratory tract infections led to progressive respiratory failure. He became fully dependent on non-invasive ventilation and by 9 years he had a tracheotomy and was established on long-term ventilation. He developed retching, vomiting and diarrhea. Chest CT showed changes consistent with chronic aspiration, but no interstitial pulmonary fibrosis. He died aged 10 from respiratory complications.

Electronic cigarette use and harm reversal: emerging evidence in the lung

Electronic cigarettes (ECs) have been rapidly gaining ground on conventional cigarettes due to their efficiency in ceasing or reducing tobacco consumption, competitive prices, and the perception of them being a much less harmful smoking alternative. Direct confirmation that long-term EC use leads to reductions in smoking-related diseases is not available and it will take a few decades before the tobacco harm reduction potential of this products is firmly established. Nonetheless, it is feasible to detect early changes in airway function and respiratory symptoms in smokers switching to e-vapor. Acute investigations do not appear to support negative respiratory health outcomes in EC users and initial findings from long-term studies are supportive of a beneficial effect of EC use in relation to respiratory outcomes. The emerging evidence that EC use can reverse harm from tobacco smoking should be taken into consideration by regulatory authorities seeking to adopt proportional measures for the e-vapor category.

New insight into the evolution of the vertebrate respiratory system and the discovery of unidirectional airflow in iguana lungs

The generally accepted framework for the evolution of a key feature of the avian respiratory system, unidirectional airflow, is that it is an adaptation for efficiency of gas exchange and expanded aerobic capacities, and therefore it has historically been viewed as important to the ability of birds to fly and to maintain an endothermic metabolism. This pattern of flow has been presumed to arise from specific features of the respiratory system, such as an enclosed intrapulmonary bronchus and parabronchi. Here we show unidirectional airflow in the green iguana, a lizard with a strikingly different natural history from that of birds and lacking these anatomical features. This discovery indicates a paradigm shift is needed. The selective drivers of the trait, its date of origin, and the fundamental aerodynamic mechanisms by which unidirectional flow arises must be reassessed to be congruent with the natural history of this lineage. Unidirectional flow may serve functions other than expanded aerobic capacity; it may have been present in the ancestral diapsid; and it can occur in structurally simple lungs.

Quantitative versus qualitative cultures of respiratory secretions for clinical outcomes in patients with ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common infectious disease in intensive care units (ICUs). The best diagnostic approach to resolve this condition remains uncertain.

OBJECTIVES

To evaluate whether quantitative cultures of respiratory secretions and invasive strategies are effective in reducing mortality in immunocompetent patients with VAP, compared with qualitative cultures and non-invasive strategies. We also considered changes in antibiotic use, length of ICU stay and mechanical ventilation.

SEARCH METHODS

We searched CENTRAL (2014, Issue 9), MEDLINE (1966 to October week 2, 2014), EMBASE (1974 to October 2014) and LILACS (1982 to October 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing respiratory samples processed quantitatively or qualitatively, obtained by invasive or non-invasive methods from immunocompetent patients with VAP and which analysed the impact of these methods on antibiotic use and mortality rates.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the trials identified in the search results and assessed studies for suitability, methodology and quality. We analysed data using Review Manager software. We pooled the included studies to yield the risk ratio (RR) for mortality and antibiotic change with 95% confidence intervals (CI).

MAIN RESULTS

Of the 5064 references identified from the electronic databases (605 from the updated search in October 2014), five RCTs (1367 patients) met the inclusion criteria. Three studies compared invasive methods using quantitative cultures versus non-invasive methods using qualitative cultures, and we used them to answer the main objective of this review. The other two studies compared invasive versus non-invasive methods, both using quantitative cultures. We combined all five studies to compare invasive versus non-invasive interventions for diagnosing VAP. The studies that compared quantitative and qualitative cultures (1240 patients) showed no statistically significant differences in mortality rates (RR 0.91; 95% CI 0.75 to 1.11). The analysis of all five RCTs showed there was no evidence of reduction in mortality in the invasive group versus the non-invasive group (RR 0.93; 95% CI 0.78 to 1.11). There were no significant differences between the interventions with respect to the number of days on mechanical ventilation, length of ICU stay or antibiotic change.

AUTHORS' CONCLUSIONS

There is no evidence that the use of quantitative cultures of respiratory secretions results in reduced mortality, reduced time in ICU and on mechanical ventilation, or higher rates of antibiotic change when compared to qualitative cultures in patients with VAP. We observed similar results when invasive strategies were compared with non-invasive strategies.

Syrian hamsters (Mesocricetus auratus) oronasally inoculated with a Nipah virus isolate from Bangladesh or Malaysia develop similar respiratory tract lesions

Nipah virus is a paramyxovirus in the genus Henipavirus, which has caused outbreaks in humans in Malaysia, India, Singapore, and Bangladesh. Whereas the human cases in Malaysia were characterized mainly by neurological symptoms and a case fatality rate of ∼40%, cases in Bangladesh also exhibited respiratory disease and had a case fatality rate of ∼70%. Here, we compared the histopathologic changes in the respiratory tract of Syrian hamsters, a well-established small animal disease model for Nipah virus, inoculated oronasally with Nipah virus isolates from human cases in Malaysia and Bangladesh. The Nipah virus isolate from Bangladesh caused slightly more severe rhinitis and bronchointerstitial pneumonia 2 days after inoculation in Syrian hamsters. By day 4, differences in lesion severity could no longer be detected. Immunohistochemistry demonstrated Nipah virus antigen in the nasal cavity and pulmonary lesions; the amount of Nipah virus antigen present correlated with lesion severity. Immunohistochemistry indicated that both Nipah virus isolates exhibited endotheliotropism in small- and medium-caliber arteries and arterioles, but not in veins, in the lung. This correlated with the location of ephrin B2, the main receptor for Nipah virus, in the vasculature. In conclusion, Nipah virus isolates from outbreaks in Malaysia and Bangladesh caused a similar type and severity of respiratory tract lesions in Syrian hamsters, suggesting that the differences in human disease reported in the outbreaks in Malaysia and Bangladesh are unlikely to have been caused by intrinsic differences in these 2 virus isolates.

A Molecular atlas of Xenopus respiratory system development

BACKGROUND

Respiratory system development is regulated by a complex series of endoderm-mesoderm interactions that are not fully understood. Recently Xenopus has emerged as an alternative model to investigate early respiratory system development, but the extent to which the morphogenesis and molecular pathways involved are conserved between Xenopus and mammals has not been systematically documented.

RESULTS

In this study, we provide a histological and molecular atlas of Xenopus respiratory system development, focusing on Nkx2.1+ respiratory cell fate specification in the developing foregut. We document the expression patterns of Wnt/β-catenin, fibroblast growth factor (FGF), and bone morphogenetic protein (BMP) signaling components in the foregut and show that the molecular mechanisms of respiratory lineage induction are remarkably conserved between Xenopus and mice. Finally, using several functional experiments we refine the epistatic relationships among FGF, Wnt, and BMP signaling in early Xenopus respiratory system development.

CONCLUSIONS

We demonstrate that Xenopus trachea and lung development, before metamorphosis, is comparable at the cellular and molecular levels to embryonic stages of mouse respiratory system development between embryonic days 8.5 and 10.5. This molecular atlas provides a fundamental starting point for further studies using Xenopus as a model to define the conserved genetic programs controlling early respiratory system development.

Three-dimensional analysis of sexual dimorphism in human thoracic vertebrae: implications for the respiratory system and spine morphology

Sexual dimorphism is important for intraspecific variation and well studied in the human skeleton. In the thoracic part of the spine sexual dimorphism is expected for differences in the respiratory system related to body mass, lung capacity, and energetics, and in the reproductive system for adaptations to pregnancy (lower spine lordosis, posture). However, little is known about sexual dimorphism in this anatomical region. We use three-dimensional (3D)-geometric morphometrics to test hypotheses on sexual dimorphism in the first 10 thoracic vertebrae (T1-T10). Forty-six 3D-landmarks were measured on vertebrae of 24 adult females and males of known age and sex. Results confirm that male vertebrae are consistently larger than female ones. Males show more dorsally oriented transverse processes and relatively larger vertebral bodies in upper and lower thoracic vertebrae. Sexual dimorphism in lower thoracic vertebrae affects the orientation of the spinous processes, which is more horizontal in females but more caudal in males. Such regional pattering of sexual dimorphism emerges also from principal component analyses reflecting a complex interaction between the effects of sex and serial position on shape variation. Greater dorsal orientation of male transverse processes reorients the ribs and could lead to greater radial thorax diameters. This fits with greater male respiratory capacities, but may indicate also greater invagination of the male spine within the thorax. Horizontal orientation of the spinous processes in females could allow for a greater thoraco-lumbar lordosis during pregnancy, but more comparative research is necessary to test these hypotheses.

Associations between inflammatory and immune response genes and adverse respiratory outcomes following exposure to outdoor air pollution: a HuGE systematic review

Variants of inflammatory and immune response genes have been associated with adverse respiratory outcomes following exposure to air pollution. However, the genes involved and their associations are not well characterized, and there has been no systematic review. Thus, we conducted a review following the guidelines of the Human Genome Epidemiology Network. Six observational studies and 2 intervention studies with 14,903 participants were included (2001-2010). Six studies showed at least 1 significant gene-pollutant interaction. Meta-analysis was not possible due to variations in genes, pollutants, exposure estimates, and reported outcomes. The most commonly studied genes were tumor necrosis factor α (TNFA) (n = 6) and toll-like receptor 4 (TLR4) (n = 3). TNFA -308G>A modified the action of ozone and nitrogen dioxide on lung function, asthma risk, and symptoms; however, the direction of association varied between studies. The TLR4 single-nucleotide polymorphisms rs1927911, rs10759931, and rs6478317 modified the association of particulate matter and nitrogen dioxide with asthma. The transforming growth factor β1 (TGFB1) polymorphism -509C>T also modified the association of pollutants with asthma. This review indicates that genes controlling innate immune recognition of foreign material (TLR4) and the subsequent inflammatory response (TGFB1, TLR4) modify the associations of exposure to air pollution with respiratory function. The associations observed have biological plausibility; however, larger studies with improved reporting are needed to confirm these findings.

Coronary artery disease concomitant with chronic obstructive pulmonary disease

BACKGROUND

Numerous epidemiologic studies have linked the presence of chronic obstructive pulmonary disease (COPD) to coronary artery disease (CAD). However, prevalence, pathological processes, clinical manifestations and therapy are still debated, as progress towards uncovering the link between these two disorders has been hindered by the complex nature of multimorbidity.

METHODS

Articles targeting CAD in patients with COPD were identified from the searches of MEDLINE and EMBASE databases in July 2013. Three authors reviewed available evidence, focusing on the latest development on disease prevalence, pathogenesis, clinical manifestations and therapeutic strategies. Both clinical trial and previous reviews have been included in this work.

RESULTS

The most accredited hypothesis asserts that the main common risk factors, that is, cigarette smoke and ageing, elicit a chronic low-grade systemic inflammatory response, which affects both cardiovascular endothelial cells and airways/lung parenchyma. The development of CAD in patients with COPD potentiates the morbidity of COPD, leading to increased hospitalizations, mortality and health costs. Moreover, correct diagnosis is challenging and therapies are not clearly defined.

CONCLUSIONS

Evidence from recently published articles highlights the importance of multimorbidity in patient management and future research. Moreover, many authors emphasize the importance of low-grade systemic inflammation as a common pathological mechanism and a possible future therapeutic target.

Overview of safety pharmacology

Safety pharmacology entails the assessment of the potential risks of novel pharmaceuticals for human use. As detailed in the ICH S7A guidelines, safety pharmacology for drug discovery involves a core battery of studies on three vital systems: central nervous (CNS), cardiovascular (CV), and respiratory. Primary CNS studies are aimed at defining compound effects on general behavior, locomotion, neuromuscular coordination, seizure threshold, and vigilance. The primary CV test battery includes an evaluation of proarrhythmic risk using in vitro tests (hERG channel and Purkinje fiber assays) and in vivo measurements in conscious animals via telemetry. Comprehensive cardiac risk assessment also includes full hemodynamic evaluation in a large, anesthetized animal. Basic respiratory function can be examined in conscious animals using whole-body plethysmography. This allows for an assessment of whether the sensitivity to respiratory-depressant effects can be enhanced by exposure to increased CO2 . Other safety pharmacology topics detailed in this unit are the timing of such studies, ethical and animal welfare issues, and statistical evaluation.