Home spirometry appears accurate and feasible for monitoring chronic respiratory disease.

https://bit.ly/42TLoYd.

Quantification of smooth muscle in human airways by polarization-sensitive optical coherence tomography requires correction for perichondrium.

Quantifying airway smooth muscle (ASM) in patients with asthma raises the possibility of improved and personalized disease management. Endobronchial polarization-sensitive optical coherence tomography (PS-OCT) is a promising quantitative imaging approach that is in the early stages of clinical translation. To date, only animal tissues have been used to assess the accuracy of PS-OCT to quantify absolute (rather than relative) ASM in cross sections with directly matched histological cross sections as validation.

Heterogeneity of Airway Smooth Muscle Remodeling in Asthma.

Ventilatory defects in asthma are heterogeneous and may represent the distribution of airway smooth muscle (ASM) remodeling. To determine the distribution of ASM remodeling in mild-severe asthma. The ASM area was measured in nine airway levels in three bronchial pathways in cases of nonfatal ( = 30) and fatal asthma ( = 20) and compared with control cases without asthma ( = 30).

Requirements and limitations of imaging airway smooth muscle throughout the lung in vivo.

Clinical visualization and quantification of the amount and distribution of airway smooth muscle (ASM) in the lungs of individuals with asthma has major implications for our understanding of airway wall remodeling as well as treatments targeted at the ASM. This paper theoretically investigates the feasibility of quantifying airway wall thickness (focusing on the ASM) throughout the lung in vivo by means of bronchoscopic polarization-sensitive optical coherence tomography (PS-OCT). Using extensive human biobank data from subjects with and without asthma in conjunction with a mathematical model of airway compliance, we define constraints that airways of various sizes pose to any endoscopic imaging technique and how this is impacted by physiologically relevant processes such as constriction, inflation and deflation.

Airway narrowing and response to simulated deep inspiration in bronchial segments from subjects with fixed airflow obstruction.

The volume fraction of extracellular matrix (ECM) within the layer of airway smooth muscle (ASM) is increased in subjects with fixed airflow obstruction. We postulated that changes in ECM within the ASM layer will impact force transmission during induced contraction and/or in response to externally applied stresses like a deep inspiration (DI). Subjects were patients undergoing lung resection surgery who were categorized as unobstructed ( = 12) or "fixed" obstructed ( = 6) on the basis of preoperative spirometry.

Robust reconstruction of local optic axis orientation with fiber-based polarization-sensitive optical coherence tomography.

It is challenging to recover local optic axis orientation from samples probed with fiber-based polarization-sensitive optical coherence tomography (PS-OCT). In addition to the effect of preceding tissue layers, the transmission through fiber and system elements, and imperfect system alignment, need to be compensated. Here, we present a method to retrieve the required correction factors from measurements with depth-multiplexed PS-OCT, which accurately measures the full Jones matrix.

Hyperinflation of bronchi in vitro impairs bronchodilation to simulated breathing and increases sensitivity to contractile activation.

Background And Objective: Lung hyperinflation and reduced bronchodilation to deep inspiration (DI) are features of chronic obstructive pulmonary disease (COPD). Hyperinflation might impair the ability of a DI to stretch airway smooth muscle (ASM), as the bronchi operate at a stiff region of the pressure-volume curve.

Methods: Bronchial segments from pig lungs were mounted in an organ bath and equilibrated at either 5 cm H O (control) or 20 cm H O (hyperinflated) transmural pressure (P ).

Airway narrowing and bronchodilation to deep inspiration in bronchial segments from subjects with and without reported asthma.

The present study presents preliminary findings on how structural/functional abnormalities of the airway wall relate to excessive airway narrowing and reduced bronchodilatory response to deep inspiration (DI) in subjects with a history of asthma. Bronchial segments were acquired from subjects undergoing surgery, mostly to remove pulmonary neoplasms. Subjects reported prior doctor-diagnosed asthma (n = 5) or had no history of asthma (n = 8).

Responsiveness of the human airway in vitro during deep inspiration and tidal oscillation.

In healthy individuals, deep inspiration produces bronchodilation and reduced airway responsiveness, which may be a response of the airway wall to mechanical stretch. The aim of this study was to examine the in vitro response of isolated human airways to the dynamic mechanical stretch associated with normal breathing. Human bronchial segments (n = 6) were acquired from patients without airflow obstruction undergoing lung resection for pulmonary neoplasms.