Clearance mechanisms are an integral part of pulmonary defense, serving to rid the lungs of inhaled particles that deposit upon airway surfaces. This is accomplished by mucociliary transport in conducting airways and to a large extent by alveolar macrophages in the respiratory region. This paper compares the effects of acute exposure to sulfuric acid (H2SO4), nitrogen dioxide (NO2), or ozone (O...

OBJECTIVES To verify in vivo whether lung cinescintigraphy confirms the effect of asbestos on the patency of the smallest airways and on the efficiency of mucociliary clearance in asbestos cement workers. METHODS 39 male subjects were examined: 30 asbestos cement workers and nine workers never exposed to occupational respiratory irritants. All subjects had a chest radiograph (International La...

BACKGROUND Patients with cystic fibrosis are known to have decreased mucociliary clearance. It has previously been shown that inhalation of a 7.0% solution of hypertonic saline significantly improved mucociliary clearance in a group of adult patients with cystic fibrosis. The aim of this study was to measure the response to increasing concentrations of inhaled hypertonic saline. METHODS Ten p...

The effects of corticosteroids on tracheal mucociliary transport (MCT) were examined in pigeons. Intramuscular administration of corticosterone had no effect at 1.0 mg/kg, while at a larger dose of 5.0 mg/kg, it slightly, but significantly increased the MCT rate. Metyrapone significantly decreased the MCT rate, and the inhibitory action was blocked by 1.0 mg/kg corticosterone. The present study...

BACKGROUND We showed previously that nasal mucociliary clearance was decreased in critically ill elderly subjects, most of whom had diabetes mellitus (DM) and/or hypertension (HTN). To determine if these changes were due to the effects of aging, disease, or critical illness, we studied nasal mucociliary clearance and mucus properties in an ambulatory population consisting of young, elderly, and...

Background Mucociliary clearance is the main self-clearing system of the nasal cavity and paranasal sinuses.This is a very important means of non specific defence against continuous organic and inorganic contamination conveyed by air. It works by trapping particles and microorganisms in the mucus and then by transporting the mucous film to the pharynx where it is eliminated with a cough or swal...

Respiratory tract mucus is a viscoelastic gel, the rheological properties of which are determined mainly by its content of mucous glycoproteins and water. The rheology and quantity of mucus, in concert with ciliary factors, are the major determinants of mucociliary clearance. A wide range of animal models for studying the secretion and clearance of mucus are available. Ex vivo models, such as t...

The mucociliary clearance system is a first line of defense against inhaled agents, and so its compromise can adversely affect health. The purpose of this paper is to provide a review of data on the effect of in vivo air pollutant exposures on the clearance of test particles from airways. Data from both animals and humans are compared whenever possible, so that estimates of human health effects...

PURPOSE This was a radioisotope study of nasal mucociliary clearance of total and subtotal nasal obstruction. METHODS Rhinoscintigraphy was performed by insufflating 1.85 MBq (69 mCi) Tc-99m MAA in 20 patients. Six cases were regarded as the control group, because the presence of small spurs does not affect nasal patency. The remaining 14 patients had various rhinopathic conditions. Two regio...

OBJECTIVE Mucociliary transport is an important defense mechanism for the airways. The aim of this study was to establish reference values for nasal mucociliary clearance time (MCT) by means of the saccharin test. SUBJECTS AND METHODS A cross-sectional, descriptive, observational study was performed. The variables studied were nasal MCT, age, and sex. We included 249 healthy nonsmokers (134 m...