Search results for "Pulmonary Alveoli"
showing 10 items of 46 documents
Influenza virus damages the alveolar barrier by disrupting epithelial cell tight junctions
2016
A major cause of respiratory failure during influenza A virus (IAV) infection is damage to the epithelial–endothelial barrier of the pulmonary alveolus. Damage to this barrier results in flooding of the alveolar lumen with proteinaceous oedema fluid, erythrocytes and inflammatory cells. To date, the exact roles of pulmonary epithelial and endothelial cells in this process remain unclear.Here, we used an in vitro co-culture model to understand how IAV damages the pulmonary epithelial–endothelial barrier. Human epithelial cells were seeded on the upper half of a transwell membrane while human endothelial cells were seeded on the lower half. These cells were then grown in co-culture and IAV wa…
Quantification of atelectatic lung volumes in two different porcine models of ARDS.
2006
BACKGROUND: Cyclic recruitment during mechanical ventilation contributes to ventilator associated lung injury. Two different pathomechanisms in acute respiratory distress syndrome (ARDS) are currently discussed: alveolar collapse vs persistent flooding of small airways and alveoli. We compare two different ARDS animal models by computed tomography (CT) to describe different recruitment and derecruitment mechanisms at different airway pressures: (i) lavage-ARDS, favouring alveolar collapse by surfactant depletion; and (ii) oleic acid ARDS, favouring alveolar flooding by capillary leakage. METHODS: In 12 pigs [25 (1) kg], ARDS was randomly induced, either by saline lung lavage or oleic acid (…
Lung Compartmentalization of Increased TNF Releasing Ability by Mononuclear Phagocytes in Pulmonary Sarcoidosis
1989
The TNF is a monokine with cytotoxic and tumor-necrosing activities; in addition, TNF may play a role in inflammatory processes. The present study evaluates spontaneous and LPS-mediated release of TNF by AMs and autologous peripheral BMs of normal subjects and patients with pulmonary sarcoidosis. A recently developed cytotoxicity assay, specific for detection of TNF activity, was applied. This study demonstrates that (1) unstimulated mononuclear phagocytes released low levels of TNF with no differences between groups; (2) when effector cells were stimulated with LPS, AMs from patients with active pulmonary sarcoidosis released more TNF than AMs recovered from normal subjects and from patien…
HRCT and scleroderma: semiquantitative evaluation of lung damage and functional abnormalities.
2007
This study sought to validate the Warrick score in the assessment of lung involvement in systemic sclerosis (SSc) and correlate the results with functional abnormalities. In addition, we propose the use of high resolution computed tomography (HRCT) indices of alveolitis and fibrosis to discriminate between different stages of the disease.Thirty-one patients with SSc (16 with the diffuse form and 15 with the limited form) underwent functional and HRCT evaluations of the lung. The semiquantitative evaluation of radiological involvement, as proposed by Warrick, provides a score for each lesion based on the severity and the extent of the pulmonary damage. In addition to the total score, indices…
A macrophage-suppressing 40-kD protein in a case of pulmonary alveolar proteinosis.
1987
Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown etiology. Macrophage dysfunctions are claimed to be involved in the pathogenesis. We investigated phagocytosis and oxidative metabolism of alveolar macrophages in a case of pulmonary alveolar proteinosis. These cells phagocytize normally and phagocytizable stimulants cause a normal oxidative burst. In response to the membrane signals phorbolmyristate acetate and aggregated immunoglobulin, however, no stimulated turnover of the oxidative metabolism can be observed. A 40-kD protein found in the lavage fluid mediates this macrophage-inhibiting effect. This phenomenon may contribute to the frequent opportunistic infections seen i…
High-Resolution Computed Tomographic Evaluation of Airway Distensibility and the Effects of Lung Inflation on Airway Caliber in Healthy Subjects and …
2001
The effects of a deep inspiration (DI) in individuals with asthma differ from those observed in healthy subjects. It has been postulated that the beneficial effect of lung inflation is mediated by airway stretch. One hypothesis to explain the defects in the function of lung inflation in asthma is that a DI may be unable to stretch the airways. This may result from attenuation of the tethering forces between the airways and the surrounding parenchyma. In the current study, we used high-resolution computed tomography (HRCT) to examine the ability of a DI to distend the airways of subjects with asthma (n = 10) compared with healthy subjects (n = 9) at baseline and after increasing airway tone …
Oxygen Radical Production by Alveolar Inflammatory Cells in Idiopathic Pulmonary Fibrosis
1990
Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory interstitial lung disease characterized by the accumulation of alveolar macrophages (AMs) and neutrophils in the lower respiratory tract, parenchymal cell injury, and fibrosis of the alveolar structure. Reactive oxygen intermediates (ROI) are claimed to be a major cause of tissue damage in IPF; however, the source of ROI has not been unequivocally identified. AMs, as well as neutrophils, are capable of releasing these agents. The contributions of these possible sources are not known. To address this question, we evaluated the spontaneous and stimulated (PMA or zymosan) ROI release of total bronchoalveolar cells and isolated AMs i…
The Effect of Spirometry on Bronchial and Alveolar Nitric Oxide in Subjects with Asthma
2013
The effect of spirometric maneuvers on exhaled nitric oxide (NO) at the constant flow rate of 50 ml/s (FE(NO)) has been studied with equivocal results. Furthermore, the effects of spirometry on bronchial NO flux (J'aw(NO)) and alveolar NO (CA(NO)), two measurements increasingly being used in clinical and research protocols, are unknown. The aim of this study was to evaluate the effect of spirometry on FE(NO), J'aw(NO), and CA(NO) in adults with asthma.Forty-four adults with asthma were studied. To assess the impact of exhaled NO measurement itself on exhaled NO values, FE(NO), J'aw(NO), and CA(NO) were obtained twice, at baseline and after a resting period of 10 min. Then spirometry (with o…
Is Health-Related Quality of Life Associated with Upper and Lower Airway Inflammation in Asthmatics?
2013
Background.Allergic diseases impair health-related quality of life (HR-QoL). However, the relationship between airway inflammation and HR-QoL in patients with asthma and rhinitis has not been fully investigated. We explored whether the inflammation of upper and lower airways is associated with HR-QoL.Methods.Twenty-two mild allergic asthmatics with concomitant rhinitis (10 males, 38 ± 17 years) were recruited. The Rhinasthma was used to identify HR-QoL, and the Asthma Control Test (ACT) was used to assess asthma control. Subjects underwent lung function and exhaled nitric oxide (eNO) test, collection of exhaled breath condensate (EBC), and nasal wash.Results.The Rhinasthma Global Summary sc…
Exhaled nitric oxide is associated with cyclic changes in sexual hormones
2013
Abstract Background We hypothesized that changes in the levels of sexual hormones during the menstrual cycle influence the concentration of nitric oxide in the exhaled air (FeNO) and alveolar exhaled nitric oxide (CANO). Methods Twelve healthy, non allergic women in their reproductive age (age range 25–37 years) were recruited. Subjects were studied, on alternate days, over the course of their menstrual cycle. At each visit, measurements of FeNO and CANO were performed. Progesterone and 17-β-estradiol concentrations were measured in salivary samples. Results Eight subjects completed the study. The levels of FeNO and CANO were 13 ± 4.7 pbb and 3.5 ± 1.9 pbb, respectively (mean ± SD). The mea…