Understanding patient experience of chronic cough in interstitial lung disease.

Rationale: Chronic cough is a common symptom in patients with interstitial lung disease (ILD), negatively contributing to health-related quality of life. Despite this, there is limited information and understanding on the experience of this group of patients with chronic cough. This study aimed to explore the symptom experiences for chronic cough in patients with ILD to identify its characteristics and impacts. Methods: A qualitative study using semi-structured telephone interviews was undertaken in 16 adults with a diagnosis of ILD of any type and severity. Patients were recruited from a quaternary referral centre in Melbourne, Australia. Interviews were transcribed verbatim and coded by two researchers using thematic analysis. Results: Patients (age range: 39-87 years, forced vital capacity: 53-107% predicted and diffusing capacity of the lung for carbon monoxide: 28-89% predicted) experienced a spectrum of cough severity and characteristics, including both dry and productive coughs. The impact of chronic cough included physical symptoms, social and emotional difficulties, and interference with work and vocational participation. Management strategies used to relieve cough included mucolytics, opiates, throat lozenges, warm drinks, pacing, breath control, relaxation exercises, movement, continuous positive airways pressure and supplemental oxygen. Patients expressed a need for further information and education regarding chronic cough, including its triggers and management. Conclusions: This study highlights the experience and significance of chronic cough in patients with ILD. The nature and severity of chronic cough in patients with ILD appears to be more heterogeneous than previously described, with physical, social and emotional impacts contributing to symptom burden.

Perceptions of Individuals With Chronic Lung Disease on Home Use of Pulse Oximetry.

BACKGROUND: Pulse oximeters are often used at home by patients with chronic respiratory diseases and more recently for remote monitoring of patients with COVID-19. There are no published data outside a supervised telemedicine setting regarding patients' experiences with these devices. Our objective was to explore patients' usage patterns and perceptions of using pulse oximetry at home. METHODS: Patients with chronic respiratory disease who had a pulse oximeter at home were recruited to complete a structured survey. RESULTS: Thirty participants with a range of chronic respiratory diseases (mean age 71 y, 16 females) were recruited. Most participants (83%) used home oxygen therapy. Pulse oximeters were bought online (46.7%), at a pharmacy (40%), at a medical equipment store (6.7%), through a clinic (3.3%), or from an oxygen supplier (3.3%). Use was self-initiated in 56.7% of cases and was based on a health care-related recommendation in 26.7% of cases. Sixty percent of participants used the oximeter daily, with 90% expressing confidence in interpreting their oximeter readings primarily due to education from health care professionals and in-patient experiences. Almost all participants adjusted their activity levels or management based upon oximeter readings. Most participants reported that using a pulse oximeter at home was helpful in judging their physical limitations and provided reassurance and confidence in their disease management. CONCLUSIONS: Subjects appeared confident in their use of home pulse oximetry. Health professionals should identify patients who use pulse oximeters for monitoring and ensure that they are able to interpret readings correctly and, if appropriate, adjust management safely.

Global architecture of the F-actin cytoskeleton regulates cell shape-dependent endothelial mechanotransduction.

Uniaxial stretch is an important biophysical regulator of cell morphology (or shape) and functions of vascular endothelial cells (ECs). However, it is unclear whether and how cell shape can independently regulate EC mechanotransductive properties under uniaxial stretch. Herein, utilizing a novel uniaxial cell-stretching device integrated with micropost force sensors, we reported the first experimental evidence showing cell shape-dependent EC mechanotransduction via cytoskeleton (CSK) contractile forces in response to uniaxial stretch. Combining experiments and theoretical modeling from first principles, we showed that it was the global architecture of the F-actin CSK that instructed the cell shape-dependent EC mechanotransductive process. Furthermore, a cell shape-dependent nature was relayed in EC mechanotransduction via dynamic focal adhesion (FA) assembly. Our results suggested a novel mechanotransductive process in ECs wherein the global architecture of the F-actin CSK, governed by cell shape, controls mechanotransduction via CSK contractile forces and force-dependent FA assembly under uniaxial stretch.

A silicone-based stretchable micropost array membrane for monitoring live-cell subcellular cytoskeletal response.

External forces are increasingly recognized as major regulators of cellular structure and function, yet the underlying mechanism by which cells sense forces and transduce them into intracellular biochemical signals and behavioral responses ('mechanotransduction') is largely undetermined. To aid in the mechanistic study of mechanotransduction, herein we devised a cell stretching device that allowed for quantitative control and real-time measurement of mechanical stimuli and cellular biomechanical responses. Our strategy involved a microfabricated array of silicone elastomeric microposts integrated onto a stretchable elastomeric membrane. Using a computer-controlled vacuum, this micropost array membrane (mPAM) was activated to apply equibiaxial cell stretching forces to adherent cells attached to the microposts. Using the mPAM, we studied the live-cell subcellular dynamic responses of contractile forces in vascular smooth muscle cells (VSMCs) to a sustained static equibiaxial cell stretch. Our data showed that in response to a sustained cell stretch, VSMCs regulated their cytoskeletal (CSK) contractility in a biphasic manner: they first acutely enhanced their contraction to resist rapid cell deformation ('stiffening') before they allowed slow adaptive inelastic CSK reorganization to release their contractility ('softening'). The contractile response across entire single VSMCs was spatially inhomogeneous and force-dependent. Our mPAM device and live-cell subcellular contractile measurements will help elucidate the mechanotransductive system in VSMCs and thus contribute to our understanding of pressure-induced vascular disease processes.