Chronic Obstructive Pulmonary Disease

Abstract

COPD is characterized by airflow limitation that is not fully reversible. The morphological basis for airflow obstruction results from a varying combination of obstructive changes in peripheral conducting airways and destructive changes in respiratory bronchioles, alveolar ducts, and alveoli. A reduction of vascularity within the alveolar septa has been reported in emphysema. Typical physiological changes reflect these structural abnormalities. Spirometry documents airflow obstruction when the FEV 1 /FVC ratio is reduced below the lower limit of normality, although in early disease stages FEV 1 and airway conductance are not affected. Current guidelines recommend testing for bronchoreversibility at least once and the postbronchodilator FEV 1 /FVC be used for COPD diagnosis; the nature of bronchodilator response remains controversial, however. One major functional consequence of altered lung mechanics is lung hyperinflation. FRC may increase as a result of static or dynamic mechanisms, or both. The link between dynamic lung hyperinflation and expiratory flow limitation during tidal breathing has been demonstrated. Hyperinflation may increase the load on inspiratory muscles, with resulting length adaptation of diaphragm. Reduction of exercise tolerance is frequently noted, with compelling evidence that breathlessness and altered lung mechanics play a major role. Lung function measurements have been traditionally used as prognostic indices and to monitor disease progression; FEV 1 has been most widely used. An increase in FVC is also considered as proof of bronchodilatation. Decades of work has provided insight into the histological, functional, and biological features of COPD. This has provided a clearer understanding of important pathobiological processes and has provided additional therapeutic options.

Percutaneous cryoablation for inoperable malignant lung tumors: Midterm results

“…An important risk factor for pneumothorax in transthoracic needle biopsy is COPD [32]. COPD is characterized by airflow limitation in the peripheral airways due to obstructive or destructive changes, and tends to have alveolar wall rupture and lung collapse [2]. In our study, COPD is a risk factor for pneumothorax.…”

AS-703026 Inhibits LPS-Induced TNFα Production through MEK/ERK Dependent and Independent Mechanisms

“…Chronic obstructive pulmonary disease (COPD) is a major health problem in China and around the world. It is a progressive disorder characterized by massive airway inflammations [ 1 , 2 , 3 ]. Physiologically, COPD is accompanied with expiratory airflow obstruction, i .…”

“…emphysema and chronic bronchitis [ 1 , 2 , 3 ]. Despite the fact that COPD’s incidence is increasing at an alarming rate, there has been no specific and/or effective therapies available to limit or prevent the progression or airway destruction of COPD [ 1 , 2 , 3 ]. Thus, there is an urgent need to explore novel agents targeting this disease.…”

Dynamics of airway response in lung microsections: a tool for studying airway-extra cellular matrix interactions

“…In addition, the preclinical significance of this technique has been reported in understanding the magnitudes and velocities of airway narrowing in a murine model of asthma (allergen-induced airway hyperresponsiveness) and in murine model of COPDs [ 38 , 39 ], which show different pattern of ASM-ECM tethering. However, decreased tethering (e.g., in emphysema) should lead to faster contractions and slower relaxations, whereas the opposite would be seen under conditions in which tethering forces are increased (e.g., in fibrosis) [ 13 , 67 ]. Under parallel physiological in-vitro conditions, mouse lung microsections incubated overnight with proteolytic enzymes elastase or collagenase showed significant loss of tethering forces [ 38 , 39 ].…”