elastin and Pneumothorax

Spontaneous pneumothorax, a prevalent medical challenge in most trauma cases, is a form of sudden lung collapse closely associated with risk factors such as lung cancer and emphysema. Our work seeks to explore and quantify the currently unknown pathological factors underlying lesion rupture in pneumothorax through biomechanical modeling. We hypothesized that lesion instability is closely associated with elastodynamic strain of the pleural membrane from pulsatile air flow and collagen-elastin dynamics. Based on the principles of continuum mechanics and fluid-structure interaction, our proposed model coupled isotropic tissue deformation with pressure from pulsatile air motion and the pleural fluid. Next, we derived mathematical instability criteria for our ordinary differential equation system and then translated these mathematical instabilities to physically relevant structural instabilities via the incorporation of a finite energy limiter. The introduction of novel biomechanical descriptions for collagen-elastin dynamics allowed us to demonstrate that changes in the protein structure can lead to a transition from stable to unstable domains in the material parameter space for a general lesion. This result allowed us to create a novel streamlined algorithm for detecting material instabilities in transient lung CT scan data via analyzing deformations in a local tissue boundary.

Topics: Algorithms; Biomechanical Phenomena; Collagen; Computational Biology; Early Diagnosis; Elastin; Fourier Analysis; Humans; Lung; Models, Biological; Nonlinear Dynamics; Pneumothorax; Respiration; Tomography, X-Ray Computed

This study presents four patients who underwent bone marrow transplantation and subsequently developed pleuroparenchymal fibroelastosis, hitherto reported as an idiopathic condition. All presented clinically with pneumothorax and subpleural fibrosis on high-resolution computed tomography. In addition to the expected obliterative bronchiolitis, histopathology showed coexistent subpleural changes, and the relationship of pathology in multiple anatomic compartments in post bone marrow transplantation pulmonary disease is discussed.

Topics: Adolescent; Adult; Autopsy; Bone Marrow Transplantation; Bronchiolitis Obliterans; Elastin; Fatal Outcome; Female; Glucocorticoids; Humans; Lung; Male; Middle Aged; Pleural Diseases; Pneumonectomy; Pneumothorax; Pulmonary Fibrosis; Recurrence; Thoracic Surgery, Video-Assisted; Tomography, X-Ray Computed; Treatment Outcome; Young Adult

Elastic fibers in 15 blebs and 17 bullae with spontaneous pneumothorax were studied by means of electron microscopy and light and electron microscopic immunohistochemistry for elastin and alpha 1-antitrypsin. Blebs were formed in association with focal organized alveoli, and bullae were formed in association with pulmonary emphysema. Both blebs and bullae had abnormal elastic fibers. Ultrastructurally, abnormal elastic fibers of blebs and bullae consisted of accumulated thick and fine fibers. Accumulated thick elastic fibers showed vacuolar changes and electron-dense granular deposits, and they were associated with spiraling collagen fibrils. These thick elastic fibers reacted evenly with antielastin antibody and also reacted with anti-alpha 1-antitrypsin antibody. They are thought to be degraded elastic fibers. Accumulated fine elastic fibers consisted of bundles of microfibrils and granular amorphous components, and they reacted with anti-elastin and anti-alpha 1-antitrypsin antibody. These fine elastic fibers are thought to be not only newly formed in the process of organization but also degraded. It is suggested that elastic fibers of blebs and bullae are degraded due to an imbalance between elastase and alpha 1-antitrypsin.

Topics: Adult; alpha 1-Antitrypsin; Blister; Elastic Tissue; Elastin; Female; Humans; Male; Microscopy, Electron; Middle Aged; Pneumothorax