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American Journal of Respiratory and... May 2024Density thresholds in computed tomography (CT) lung scans quantify air trapping (AT) at the whole-lung level but are not informative for AT in specific bronchopulmonary...
Density thresholds in computed tomography (CT) lung scans quantify air trapping (AT) at the whole-lung level but are not informative for AT in specific bronchopulmonary segments. To apply a segment-based measure of AT in asthma to investigate the clinical determinants of AT in asthma. In each of 19 bronchopulmonary segments in CT lung scans from 199 patients with asthma, AT was categorized as present if lung attenuation was less than -856 Hounsfield units at expiration in ⩾15% of the lung area. The resulting AT segment score (0-19) was related to patient outcomes. AT varied at the lung segment level and tended to persist at the patient and lung segment levels over 3 years. Patients with widespread AT (⩾10 segments) had more severe asthma ( < 0.05). The mean (±SD) AT segment score in patients with a body mass index ⩾30 kg/m was lower than in patients with a body mass index <30 kg/m (3.5 ± 4.6 vs. 5.5 ± 6.3; = 0.008), and the frequency of AT in lower lobe segments in obese patients was less than in upper and middle lobe segments (35% vs. 46%; = 0.001). The AT segment score in patients with sputum eosinophils ⩾2% was higher than in patients without sputum eosinophilia (7.0 ± 6.1 vs. 3.3 ± 4.9; < 0.0001). Lung segments with AT more frequently had airway mucus plugging than lung segments without AT (48% vs. 18%; ⩽ 0.0001). In patients with asthma, air trapping is more severe in those with airway eosinophilia and mucus plugging, whereas those who are obese have less severe trapping because their lower lobe segments are spared.
Topics: Humans; Asthma; Male; Female; Middle Aged; Obesity; Adult; Eosinophilia; Tomography, X-Ray Computed; Lung; Aged; Body Mass Index
PubMed: 38113166
DOI: 10.1164/rccm.202305-0802OC -
Journal of Electrocardiology May 2024Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, and its incidence has grown within several years, quickly becoming the third... (Review)
Review
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, and its incidence has grown within several years, quickly becoming the third leading cause of mortality. The disease is characterized by alveolar destruction, air-trapping, and chronic inflammation due to persistent exposure to a large spectrum of harmful particles. The diagnosis of COPD is made by demonstration of persistent and not fully reversible airflow limitation, and different phenotypes may be recognized based on pathophysiological, clinical, and radiological features. However, COPD is a systemic disease with effects involving several organs. For example, mechanical and functional alterations secondary to COPD involve heart function. Indeed, cardiovascular diseases are highly prevalent in patients affected by COPD and represent the primary cause of mortality in such patients. An electrocardiogram is a simple and cheap test that gives much information about the heart status of COPD patients. Consequently, variations from "normality" can be appreciated in these patients, with the most frequent abnormalities being P-wave, QRS axis, and ventricular repolarization abnormalities, in addition to conduction alterations and a vast number of arrhythmias. As a result, ECG should be routinely performed as a valuable tool to recognize alterations due to COPD (i.e., mechanical and functional) and possible associated heart diseases. This review aims to describe the typical ECG features in most COPD patients and to provide a systematic summary that can be used in clinical practice.
PubMed: 38865856
DOI: 10.1016/j.jelectrocard.2024.05.083 -
BMC Pulmonary Medicine Jan 2024In tobacco-exposed persons with preserved spirometry (active smoking or secondhand smoke [SHS] exposure), air trapping can identify a subset with worse symptoms and... (Randomized Controlled Trial)
Randomized Controlled Trial
Effect of twice daily inhaled albuterol on cardiopulmonary exercise outcomes, dynamic hyperinflation, and symptoms in secondhand tobacco-exposed persons with preserved spirometry and air trapping: a randomized controlled trial.
BACKGROUND
In tobacco-exposed persons with preserved spirometry (active smoking or secondhand smoke [SHS] exposure), air trapping can identify a subset with worse symptoms and exercise capacity. The physiologic nature of air trapping in the absence of spirometric airflow obstruction remains unclear. The aim of this study was to examine the underlying pathophysiology of air trapping in the context of preserved spirometry and to determine the utility of bronchodilators in SHS tobacco-exposed persons with preserved spirometry and air trapping.
METHODS
We performed a double-blinded placebo-controlled crossover randomized clinical trial in nonsmoking individuals at risk for COPD due to exposure to occupational SHS who had preserved spirometry and air trapping defined as either a residual volume-to-total lung capacity ratio (RV/TLC) > 0.35 or presence of expiratory flow limitation (EFL, overlap of tidal breathing on maximum expiratory flow-volume loop) on spirometry at rest or during cardiopulmonary exercise testing (CPET). Those with asthma or obesity were excluded. Participants underwent CPET at baseline and after 4-week trials of twice daily inhalation of 180 mcg of albuterol or placebo separated by a 2-week washout period. The primary outcome was peak oxygen consumption (VO) on CPET. Data was analyzed by both intention-to-treat and per-protocol based on adherence to treatment prescribed.
RESULTS
Overall, 42 participants completed the entire study (66 ± 8 years old, 91% female; forced expiratory volume in 1 s [FEV] = 103 ± 16% predicted; FEV to forced vital capacity [FVC] ratio = 0.75 ± 0.05; RV/TLC = 0.39 ± 0.07; 85.7% with EFL). Adherence was high with 87% and 93% of prescribed doses taken in the treatment and placebo arms of the study, respectively (P = 0.349 for comparison between the two arms). There was no significant improvement in the primary or secondary outcomes by intention-to-treat or per-protocol analysis. In per-protocol subgroup analysis of those with RV/TLC > 0.35 and ≥ 90% adherence (n = 27), albuterol caused an improvement in peak VO (parameter estimate [95% confidence interval] = 0.108 [0.014, 0.202]; P = 0.037), tidal volume, minute ventilation, dynamic hyperinflation, and oxygen-pulse (all P < 0.05), but no change in symptoms or physical activity.
CONCLUSIONS
Albuterol may improve exercise capacity in the subgroup of SHS tobacco-exposed persons with preserved spirometry and substantial air trapping. These findings suggest that air trapping in pre-COPD may be related to small airway disease that is not considered significant by spirometric indices of airflow obstruction.
Topics: Aged; Female; Humans; Male; Middle Aged; Albuterol; Exercise; Forced Expiratory Volume; Lung; Pulmonary Disease, Chronic Obstructive; Spirometry; Vital Capacity
PubMed: 38245665
DOI: 10.1186/s12890-023-02808-7 -
Environmental Pollution (Barking, Essex... Oct 2023Air pollution has been associated with the development of atherosclerosis; however, the pathophysiological mechanisms underlying pro-atherosclerotic effects of air...
Pro-inflammation and pro-atherosclerotic responses to short-term air pollution exposure associated with alterations in sphingolipid ceramides and neutrophil extracellular traps.
Air pollution has been associated with the development of atherosclerosis; however, the pathophysiological mechanisms underlying pro-atherosclerotic effects of air pollution exposure remain unclear. We conducted a prospective panel study in Beijing and recruited 152 participants with four monthly visits from September 2019 to January 2020. Linear mixed-effect models were applied to estimate the associations linking short-term air pollution exposure to biomarkers relevant to ceramide metabolism, pro-inflammation (neutrophil extracellular traps formation and systemic inflammation) and pro-atherosclerotic responses (endothelial stimulation, plaque instability, coagulation activation, and elevated blood pressure). We further explored whether ceramides and inflammatory indicators could mediate the alterations in the profiles of pro-atherosclerotic responses. We found that significant increases in levels of circulating ceramides of 9.7% (95% CIs: 0.7, 19.5) to 96.9% (95% CIs: 23.1, 214.9) were associated with interquartile range increases in moving averages of ambient air pollutant metrics, including fine particulate matter (PM), black carbon, particles in size fractions of 100-560 nm, nitrogen dioxide, carbon monoxide and sulfur dioxide at prior up to 7 days. Higher air pollution levels were also associated with activated neutrophils (increases in citrullinated histone H3, neutrophil elastase, double-stranded DNA, and myeloperoxidase) and exacerbation of pro-atherosclerotic responses (e.g., increases in vascular endothelial growth factor, lipoprotein-associated phospholipase A2, matrix metalloproteinase-8, P-selectin, and blood pressure). Mediation analyses further showed that dysregulated ceramide metabolism and potentiated inflammation could mediate PM-associated pro-atherosclerotic responses. Our findings extend the understanding on potential mechanisms of air pollution-associated atherosclerosis, and suggest the significance of reducing air pollution as priority in urban environments.
Topics: Humans; Ceramides; Sphingolipids; Extracellular Traps; Prospective Studies; Vascular Endothelial Growth Factor A; Air Pollution; Air Pollutants; Inflammation; Particulate Matter; Atherosclerosis; Environmental Exposure
PubMed: 37541379
DOI: 10.1016/j.envpol.2023.122301 -
The Analyst Dec 2023Partitioning is the core technology supporting digital assays. It divides a sample into thousands of individual reactors prior to amplification and absolute...
Partitioning is the core technology supporting digital assays. It divides a sample into thousands of individual reactors prior to amplification and absolute quantification of target molecules. Thermoplastics are attractive materials for large scale manufacturing, however they have been seldomly used for fabricating partitioning arrays. Patitioning in thermoplastic devices has proven difficult due to the challenge of efficiently displacing the air trapped in the nanoliter structures during priming of thousands of chambers. Here, we report the design of an array of chambers made of thermoplastics where the progression of the liquid-air interface is controlled by capillary effects. Our device performs robust partitioning over a wide range of pressures and can be actuated at low pressure by a simple micropipette. Our thermoplastic device lays the foundation to cost-effective and instrument-free partitioning platforms, which could be deployed in low-resource settings.
PubMed: 37982399
DOI: 10.1039/d3an01869e -
Advanced Materials (Deerfield Beach,... May 2024Recently, utilizing the air breakdown effect in the charge excitation strategy proves as an efficient charge injection technique to increase the surface charge density...
Recently, utilizing the air breakdown effect in the charge excitation strategy proves as an efficient charge injection technique to increase the surface charge density of dielectric polymers for triboelectric nanogenerators (TENGs). However, quantitative characterization of the ability of dielectric polymers to trap reverse charges and the effect on the startup time of secondary self-charge excitation (SSCE) are essential for extensive applications. Here, an ultra-fast charge self-injection technique based on a self-charge excitation strategy is proposed, and a standard method to quantify the charge trapping and de-trapping abilities of 23 traditional tribo-materials is introduced. Further, the relationship among the distribution of dielectric intrinsic deep, shallow trap states, and transportation of trapped charges is systematically analyzed in this article. It shows that the de-trapping rate of charges directly determines the reactivation and failure of SSCE. Last, independent of TENG contact efficiency, an ultra-high charge density of 2.67 mC m and an ultra-fast startup time of SSCE are obtained using a 15 µm poly(vinylidene fluoride-trifluoroethylene) film, breaking the historical record for material modification. As a standard for material selection, this work quantifies the charge trapping and de-trapping ability of the triboelectric dielectric series and provides insights for understanding the charge transport in dielectrics.
PubMed: 38314966
DOI: 10.1002/adma.202312148 -
Respiratory Research Nov 2023FOOTPRINTS is a prospective, longitudinal, 3-year study assessing the association between biomarkers of inflammation/lung tissue destruction and chronic obstructive...
BACKGROUND
FOOTPRINTS is a prospective, longitudinal, 3-year study assessing the association between biomarkers of inflammation/lung tissue destruction and chronic obstructive pulmonary disease (COPD) severity and progression in ex-smokers with mild-to-severe COPD. Here, we present baseline characteristics and select biomarkers of study subjects.
METHODS
The methodology of FOOTPRINTS has been published previously. The study population included ex-smokers with a range of COPD severities (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages 1-3), ex-smokers with COPD and alpha-1-antitrypsin deficiency (A1ATD) and a control group of ex-smokers without airflow limitation (EwAL). At study entry, data were collected for: demographics, disease characteristics, history of comorbidities and COPD exacerbations, symptoms, lung function and volume, exercise capacity, soluble biomarkers, and quantitative and qualitative computed tomography. Baseline data are presented with descriptive statistical comparisons for soluble biomarkers in the individual GOLD and A1ATD groups versus EwAL.
RESULTS
In total, 463 subjects were enrolled. The per-protocol set comprised 456 subjects, mostly male (64.5%). The mean (standard deviation) age was 60.7 (6.9) years. At baseline, increasing pulmonary symptoms, worse lung function, increased residual volume, reduced diffusing capacity of the lung for carbon monoxide (DLco) and greater prevalence of centrilobular emphysema were observed with increasing disease severity amongst GOLD 1-3 subjects. Subjects with A1ATD (n = 19) had similar lung function parameters to GOLD 2-3 subjects, a high residual volume comparable to GOLD 3 subjects, and similar air trapping to GOLD 2 subjects. Compared with EwAL (n = 61), subjects with A1ATD had worse lung function, increased residual volume, reduced DLco, and a greater prevalence of confluent or advanced destructive emphysema. The soluble inflammatory biomarkers white blood cell count, fibrinogen, high-sensitivity C-reactive protein and plasma surfactant protein were higher in GOLD 1-3 groups than in the EwAL group. Interleukin-6 was expressed less often in EwAL subjects compared with subjects in the GOLD and A1ATD groups. Soluble receptor for advanced glycation end product was lowest in GOLD 3 subjects, indicative of more severe emphysema.
CONCLUSIONS
These findings provide context for upcoming results from FOOTPRINTS, which aims to establish correlations between biomarkers and disease progression in a representative COPD population.
TRIAL REGISTRATION NUMBER
NCT02719184, study start date 13/04/2016.
Topics: Humans; Male; Middle Aged; Female; Longitudinal Studies; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Lung; alpha 1-Antitrypsin Deficiency; Phenotype; Biomarkers; Forced Expiratory Volume
PubMed: 37978492
DOI: 10.1186/s12931-023-02584-2 -
BMJ Case Reports Sep 2023A man in his 70s in a rehabilitation hospital, post cerebral infarct, became acutely short of breath with reduced oxygen saturations and an elevated...
A man in his 70s in a rehabilitation hospital, post cerebral infarct, became acutely short of breath with reduced oxygen saturations and an elevated d-dimer.Non-occlusive filling defects were noted on the CT pulmonary angiogram in the proximal left pulmonary arteries. There was associated hypoplasia of the distal pulmonary arterial tree in the left hemithorax with left pulmonary vein stenosis. Review of previous imaging suggested this oligaemia was longstanding.Although filling defects in the pulmonary arteries usually correspond to embolic material, in our patient they were too dense to represent thrombus and probably represented flow-related artefacts in the setting of chronic air trapping.Given the associated volume loss, bronchiectasis and bronchial wall thickening in the left hemithorax Swyer-James-McLeod syndrome was thought to be the most likely underlying cause.
Topics: Male; Humans; Lung; Pulmonary Embolism; Bronchiectasis; Pulmonary Artery; Angiography; Lung, Hyperlucent
PubMed: 37751970
DOI: 10.1136/bcr-2023-255056 -
Transplantation Nov 2023Bronchiolitis obliterans syndrome (BOS) after lung transplantation is characterized by fibrotic small airway remodeling, recognizable on high-resolution computed...
BACKGROUND
Bronchiolitis obliterans syndrome (BOS) after lung transplantation is characterized by fibrotic small airway remodeling, recognizable on high-resolution computed tomography (HRCT). We studied the prognostic value of key HRCT features at BOS diagnosis after lung transplantation.
METHODS
The presence and severity of bronchiectasis, mucous plugging, peribronchial thickening, parenchymal anomalies, and air trapping, summarized in a total severity score, were assessed using a simplified Brody II scoring system on HRCT at BOS diagnosis, in a cohort of 106 bilateral lung transplant recipients transplanted between January 2004 and January 2016. Obtained scores were subsequently evaluated regarding post-BOS graft survival, spirometric parameters, and preceding airway infections.
RESULTS
A high total Brody II severity score at BOS diagnosis (P = 0.046) and high subscores for mucous plugging (P = 0.0018), peribronchial thickening (P = 0.0004), or parenchymal involvement (P = 0.0121) are related to worse graft survival. A high total Brody II score was associated with a shorter time to BOS onset (P = 0.0058), lower forced expiratory volume in 1 s (P = 0.0006) forced vital capacity (0.0418), more preceding airway infections (P = 0.004), specifically with Pseudomonas aeruginosa (P = 0.002), and increased airway inflammation (P = 0.032).
CONCLUSIONS
HRCT findings at BOS diagnosis after lung transplantation provide additional information regarding its underlying pathophysiology and for future prognosis of graft survival.
Topics: Humans; Prognosis; Bronchiolitis Obliterans; Transplant Recipients; Lung; Lung Transplantation; Tomography, X-Ray Computed; Bronchiolitis Obliterans Syndrome; Forced Expiratory Volume; Retrospective Studies
PubMed: 37870882
DOI: 10.1097/TP.0000000000004726