Pulmonary Manifestations of Collagen Diseases

Characterization of the effect of chromium salts on tropocollagen molecules and molecular aggregates

Though the capability of chromium treatment to improve the stability and mechanical properties of collagen fibrils is well-known, the influence of different chromium salts on collagen molecules (tropocollagen) is not well characterized. In this study, the effect of Cr³⁺ treatment on the conformation and hydrodynamic properties of collagen was studied using atomic force microscopy (AFM) and dynamic light scattering (DLS). Statistical analysis of contours of adsorbed tropocollagen molecules using the two-dimensional worm-like chain model revealed a reduction of the persistence length (i.e., the increase of flexibility) from ≈72 nm in water to ≈56-57 nm in chromium (III) salt solutions. DLS studies demonstrated an increase of the hydrodynamic radius from ≈140 nm in water to ≈190 nm in chromium (III) salt solutions, which is associated with protein aggregation. The kinetics of collagen aggregation was shown to be ionic strength dependent. Collagen molecules treated with three different chromium (III) salts demonstrated similar properties such as flexibility, aggregation kinetics, and susceptibility to enzymatic cleavage. The observed effects are explained by a model that considers the formation of chromium-associated intra- and intermolecular crosslinks. The obtained results provide novel insights into the effect of chromium salts on the conformation and properties of tropocollagen molecules.

Relationship between air pollution exposure and the progression of idiopathic pulmonary fibrosis in Madrid: Chronic respiratory failure, hospitalizations, and mortality. A retrospective study

Introduction

Air pollution has a significant impact on the morbidity and mortality of various respiratory diseases. However, this has not been widely studied in diffuse interstitial lung diseases, specifically in idiopathic pulmonary fibrosis.

Objective

In this study we aimed to assess the relationship between four major air pollutants individually [carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and nitrogen oxides (NOx)] and the development of chronic respiratory failure, hospitalization due to respiratory causes and mortality in patients with idiopathic pulmonary fibrosis.

Methods

We conducted an exploratory retrospective panel study from 2011 to 2020 in 69 patients with idiopathic pulmonary fibrosis from the pulmonary medicine department of a tertiary hospital. Based on their geocoded residential address, levels of each pollutant were estimated 1, 3, 6, 12, and 36 months prior to each event (chronic respiratory failure, hospital admission and mortality). Data was collected from the air quality monitoring stations of the Community of Madrid located <3.5 km (2.2 miles) from each patient's home.

Results

The increase in average values of CO [OR 1.62 (1.11–2.36) and OR 1.84 (1.1–3.06)], NO2 [OR 1.64 (1.01–2.66)], and NOx [OR 1.11 (1–1.23) and OR 1.19 (1.03–1.38)] were significantly associated with the probability of developing chronic respiratory failure in different periods. In addition, the averages of NO2, O3, and NOx were significantly associated with the probability of hospital admissions due to respiratory causes and mortality in these patients.

Conclusion

Air pollution is associated with an increase in the probability of developing chronic respiratory failure, hospitalization due to respiratory causes and mortality in patients with idiopathic pulmonary fibrosis.

Paediatric and adult bronchiectasis: Specific management with coexisting asthma, COPD, rheumatological disease and inflammatory bowel disease

Bronchiectasis, conventionally defined as irreversible dilatation of the bronchial tree, is generally suspected on a clinical basis and confirmed by means of chest high-resolution computed tomography. Clinical manifestations, including chronic productive cough and endobronchial suppuration with persistent chest infection and inflammation, may deeply affect quality of life, both in children/adolescents and adults. Despite many cases being idiopathic or post-infectious, a number of specific aetiologies have been traditionally associated with bronchiectasis, such as cystic fibrosis (CF), primary ciliary dyskinesia or immunodeficiencies. Nevertheless, bronchiectasis may also develop in patients with bronchial asthma; chronic obstructive pulmonary disease; and, less commonly, rheumatological disorders and inflammatory bowel diseases. Available literature on the development of bronchiectasis in these conditions and on its management is limited, particularly in children. However, bronchiectasis may complicate the clinical course of the underlying condition at any age, and appropriate management requires an integration of multiple skills in a team of complementary experts to provide the most appropriate care to affected children and adolescents. The present review aims at summarizing the current knowledge and available evidence on the management of bronchiectasis in the other conditions mentioned and focuses on the new therapeutic strategies that are emerging as promising tools for improving patients' quality of life.