Search results for "RESPIRATORY SYSTEM"
showing 10 items of 1829 documents
The relationship between asthma and allergic rhinitis: exploring the basis for a common pathophysiology
2003
Summary Most patients with asthma also have rhinitis, and the same inflammatory cells and mechanisms are present in bronchial and nasal mucosa, thus leading to the concept of ‘one airway, one disease’. This concept is further substantiated by evidence of nasal inflammation in asthma, and bronchial inflammation and hyperresponsiveness in rhinitis. Endobronchial allergen challenge induces nasal and bronchial symptoms as well as reductions in pulmonary function and nasal patency. Likewise, treating rhinitis can improve the symptoms of asthma. There are some notable pathophysiological differences between the nose and the bronchi, for example airway remodelling appears to be less extensive in th…
Macrophages govern antiviral responses in human lung tissues protected from SARS-CoV-2 infection
2021
SUMMARYThe majority of SARS-CoV-2 infections among healthy individuals result in asymptomatic to mild disease. However, the immunological mechanisms defining effective lung tissue protection from SARS-CoV-2 infection remain elusive. Unlike mice solely engrafted with human fetal lung xenograft (fLX), mice co-engrafted with fLX and a myeloid-enhanced human immune system (HNFL mice) are protected against SARS-CoV-2 infection, severe inflammation, and histopathology. Effective control of viral infection in HNFL mice associated with significant macrophage infiltration, and the induction of a potent macrophage-mediated interferon response. The pronounced upregulation of the USP18-ISG15 axis (a ne…
Remote Ischemic Preconditioning Decreases Oxidative Lung Damage After Pulmonary Lobectomy
2017
BACKGROUND:During lobectomy in patients with lung cancer, the operated lung is often collapsed and hypoperfused. Ischemia/reperfusion injury may then occur when the lung is re-expanded. We hypothesized that remote ischemic preconditioning (RIPC) would decrease oxidative lung damage and improve gas e
Mast cells and the development of allergic airway disease
2008
Murine models have highlighted the importance of T-cells and TH2 cytokines in development of allergen-induced airway disease. In contrast, the role of mast cells for the development of allergic airway disease has been controversial. Recent studies in murine models demonstrate a significant contribution of mast cells during the development of airway hyperresponsiveness and airway inflammation. Furthermore these models have allowed identifying certain mast cell-produced mediators (e.g. histamine and leukotriene B4) to be involved in the recruitment of effector T-cells into the lung. Additionally, mast cell-produced TNF can directly activate TH2 cells and contribute to the development of aller…
DPP-4 is overexpressed in lung tissue from idiopathic pulmonary patients and activates lung fibroblasts
2020
Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible form of fibrotic interstitial lung disease, characterized by uncontrolled fibroblast invasion. Dipeptidyl peptidase-4 (DPP-4)/ glucagon-like peptide 1 (GLP-1) system is involved in multiple effects, including cardiac, liver or kidney fibrosis. However, its implication in IPF has not been described. Objective: To analyse the implication of DPP4/GLP1 system in IPF. Methods: Protein expression of DPP4, GLP-1 and GLP-1 receptor was analyzed in lung tissues from 7 IPF patients. TGFβ1-induced fibroblast to myofibroblast transition (FMT), epithelial to mesenchymal transition (EMT) and mesothelial to mesenchymal trans…
Kontrastmittelverstärkte 3D-MR-Perfusion der Lunge: Einsatz paralleler Bildgebungstechniken bei gesunden Probanden
2004
PURPOSE Evaluation of lung perfusion by contrast-enhanced 3D MRI using partial parallel imaging techniques. MATERIALS AND METHODS Eight healthy volunteers were examined using a contrast-enhanced dynamic FLASH 3D sequence with partial parallel imaging technique at 1.5 T MRI with a TA of 1.5 sec. The whole lung was covered by 36 coronal slices. A ventral, middle and dorsal slice of each lung was manually segmented and signal-to-time curves were computed. For absolute quantification of blood flow through the right and left pulmonary artery, phase-contrast flow measurements were performed. RESULTS No significant difference was found between the signal intensity in the right (8.9 +/- 2.6) and le…
Determination Of Pulmonary Parameters (V̇A, $$ {D_{{L_{{O^2}}}}} $$ ) From Arterial O2 and CO2 Partial Pressures During Exercise
1984
The arterial O2 and CO2 partial pressures mainly depend on the ventilation-perfusion ratio VA/Q and on the O2 diffusing capacity-perfusion ratio DLO2/Q. According to RAHN’s VA/Q concept, the dependence of the alveolar O2 and CO2 partial pressures on the ventilation-perfusion ratio can be determined graphically, and displayed in the form of a diagram (2,3). However, the application of the RAHN diagram is limited by the fact that during the passage of the blood through the lung capillaries, a complete adjustment of the capillary O2 partial pressure to the alveolar value frequently does not occur. This is particularly valid for gas exchange during exercise. For this case, the alveolar-endcapil…
Elucidation of structure-function relationships in the lung: contributions from hyperpolarized 3 helium MRI
2002
Magnetic resonance imaging (MRI) using hyperpolarized 3helium (He) gas as the source of signal provides new physiological insights into the structure-function relationships of the lung. Traditionally, lung morphology has been visualized by chest radiography and computed tomography, whereas lung function was assessed by using nuclear medicine. As all these techniques rely on ionizing radiation, MRI has some inherent advantages. 3He MRI is based on 'optical pumping' of the 3He gas which increases the nuclear spin polarization by four to five orders of magnitude translating into a massive gain in signal. Hyperpolarized 3He gas is administered as an inhaled 'contrast agent' and allows for selec…
Structural Remodeling of the Post‐pneumonectomy Lung is Characterized by Septal Retraction and Alveolar Duct Dilation
2015
Murine pneumonectomy (PNX) is an established model of adult compensatory lung growth, involving structural remodeling of the peripheral parenchyma. Following left PNX, positron emission tomography and computerized tomography have demonstrated heterogeneous growth patterns within the remaining right lung. To characterize the structural changes associated with these observations, we analyzed histological sections of the right lung between 3 and 22 days after PNX. Within 3 days of PNX, alveolar septae were significantly shorter (p<0.05) in a majority of alveolar ducts, while septal angle remained unchanged. Septal retraction resulted in an apparent dilation of the alveolar duct with a signific…
Cajaninstilbene acid (CSA) exerts cytoprotective effects against oxidative stress through the Nrf2-dependent antioxidant pathway.
2013
Cajaninstilbene acid (CSA), an active compound separated from pigeon pea leaves, possesses the highly efficient antioxidant activities. Transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular oxidative stress. This study examined the role of Nrf2 in CSA-mediated antioxidant effects on human hepatocarcinoma (HepG2) cell line. The generation of reactive oxygen species (ROS) upon H2O2 and CSA treatment was lower than that of H2O2 alone. CSA activated Nrf2 as evaluated by Western blotting. A luciferase reporter assay also demonstrated that CSA-activated signaling resulted in the increased transcriptional activity of Nrf2 through binding to t…