DOES LUNG RETENTION OF INHALED PARTICLES DEPEND ON THEIR GEOMETRIC DIAMETER?

2000 ◽  
Vol 26 (6) ◽  
pp. 437-455 ◽  
Author(s):  
Philipson Klas ◽  
Falk Rolf ◽  
Svartengren Magnus ◽  
Jarvis Naomi ◽  
Bailey Michael ◽  
...  
Keyword(s):  
Inhaled Particles ◽  
Lung Retention

Mucociliary clearance of inhaled particles measured at 2 h after ozone exposure in humans

1993 ◽  
Vol 74 (6) ◽  
pp. 2984-2989 ◽  
Author(s):  
T. R. Gerrity ◽  
W. D. Bennett ◽  
H. Kehrl ◽  
P. J. DeWitt
Keyword(s):  
Pulmonary Function ◽  
Time Course ◽  
Ozone Exposure ◽  
Mucociliary Transport ◽  
Pulmonary Epithelium ◽  
Final Particle ◽  
Inhaled Particles ◽  
Lung Retention ◽  
Before And After ◽  
Clean Air

Acute exposure of humans to ozone is known to acutely cause pulmonary function decrements, inflammation, and increased permeability of pulmonary epithelium. A single study in humans has also shown that mucociliary transport increases during acute ozone exposure. Because different responses have shown a different time course of recovery after exposure, it was important to examine mucociliary transport at a different time after the cessation of ozone exposure. We exposed 15 healthy male and female nonsmoking subjects, on different occasions, to clean air and 0.4 ppm ozone for 1 h while they exercised continuously. Pulmonary function was measured immediately before and after exposure and 90 min and 24 h after exposure. Between 2 and 5 h after each exposure, retention of inhaled 5-microns mass median aerodynamic diameter 99mTc-labeled Fe2O3 particles was measured. Each subject returned the next day for a final particle retention measurement. Despite significant changes in pulmonary function, there was no difference in mean whole lung retention time of particles between clean air [77.9 +/- 0.8 (SE) min] and ozone (78.0 +/- 0.8 min) exposures, indicating that mucociliary transport is unaffected by ozone exposure when it is measured 2 h after exposure.

scholarly journals Time course of lung retention and toxicity of inhaled particles: short-term exposure to nano-Ceria

2014 ◽  
Vol 88 (11) ◽  
pp. 2033-2059 ◽  
Author(s):  
Jana Keller ◽  
Wendel Wohlleben ◽  
Lan Ma-Hock ◽  
Volker Strauss ◽  
Sibylle Gröters ◽  
...  
Keyword(s):  
Time Course ◽  
Short Term ◽  
Inhaled Particles ◽  
Short Term Exposure ◽  
Lung Retention ◽  
Nano Ceria

Effect of exercise on deposition and subsequent retention of inhaled particles

1985 ◽  
Vol 59 (4) ◽  
pp. 1046-1054 ◽  
Author(s):  
W. D. Bennett ◽  
M. S. Messina ◽  
G. C. Smaldone
Keyword(s):  
Particle Deposition ◽  
Human Subjects ◽  
Regional Distribution ◽  
Bicycle Ergometer ◽  
Inhaled Particles ◽  
Significant Difference ◽  
Lung Retention ◽  
Deposition Fraction ◽  
Normal Human ◽  
Rest And Exercise

To investigate the effect of exercise and its associated increase in ventilation on the deposition and subsequent retention of inhaled particles, we measured the fractional and regional lung deposition of a radioactively tagged (99mTc) monodisperse aerosol (2.6 microns mass median aerodynamic diam) in normal human subjects at rest and while exercising on a bicycle ergometer. Breath-by-breath deposition fraction (DF) was measured throughout the aerosol exposures by Tyndallometry. Following each exposure gamma camera analysis was used to 1) determine the regional distribution of deposited particles and 2) monitor lung retention for 2.5 h and again at 24 h. We found that DF was unchanged between ventilation at rest (6–10 l/min) and exercise (32–46 l/min). Even though mouth deposition was enhanced with exercise, it was not large enough to produce a significant difference in the deposition fraction of the lung (DFL) between resting and exercise exposures. The central-to-peripheral distribution of deposited aerosol was larger for the exercise vs. resting exposure, reflecting a shift of particle deposition to more central bronchial airways. Apical-to-basal distribution was not different for the two exposures. Retention at 2.5 h and 24 h (R24) was reduced following the exercise vs. the resting exposure, consistent with greater bronchial deposition during exercise. The product of DFL and R24 gave a measure of fractional burden at 24 h (B24), i.e., the fraction of inhaled aerosol residing in the lungs 24 h after exposure. B24 was not significantly different between rest and exercise exposures.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

scholarly journals Signaling Control of Mucociliary Epithelia: Stem Cells, Cell Fates, and the Plasticity of Cell Identity in Development and Disease

2021 ◽  
pp. 1-18
Author(s):  
Peter Walentek
Keyword(s):  
Stem Cells ◽  
Mucociliary Clearance ◽  
Cell Types ◽  
Secretory Cells ◽  
Chronic Obstructive ◽  
Cell Identity ◽  
Obstructive Pulmonary Disease ◽  
Congenital Diseases ◽  
Inhaled Particles ◽  
Mucociliary Epithelia

Mucociliary epithelia are composed of multiciliated, secretory, and stem cells and line various organs in vertebrates such as the respiratory tract. By means of mucociliary clearance, those epithelia provide a first line of defense against inhaled particles and pathogens. Mucociliary clearance relies on the correct composition of cell types, that is, the proper balance of ciliated and secretory cells. A failure to generate and to maintain correct cell type composition and function results in impaired clearance and high risk to infections, such as in congenital diseases (e.g., ciliopathies) as well as in acquired diseases, including asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). While it remains incompletely resolved how precisely cell types are specified and maintained in development and disease, many studies have revealed important mechanisms regarding the signaling control in mucociliary cell types in various species. Those studies not only provided insights into the signaling contribution to organ development and regeneration but also highlighted the remarkable plasticity of cell identity encountered in mucociliary maintenance, including frequent trans-differentiation events during homeostasis and specifically in disease. This review will summarize major findings and provide perspectives regarding the future of mucociliary research and the treatment of chronic airway diseases associated with tissue remodeling.

A, Model for Tracheobronchial Clearance of Inhaled Particles in Man and a Comparison with Data

1979 ◽  
Vol BME-26 (11) ◽  
pp. 624-630 ◽  
Author(s):  
Peter S. Lee ◽  
Timothy R. Gerrity ◽  
Frank J. Hass ◽  
Ruy V. Lourenco
Keyword(s):  
Inhaled Particles

scholarly journals Inhalers and nebulizers: basic principles and preliminary measurements

2018 ◽  
Vol 180 ◽  
pp. 02068
Author(s):  
Ondrej Misik ◽  
Frantisek Lizal ◽  
Vahid Farhikhteh Asl ◽  
Miloslav Belka ◽  
Jan Jedelsky ◽  
...  
Keyword(s):  
Hospital Care ◽  
Aerosol Particles ◽  
Experimental Setup ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Basic Principles ◽  
Physical Mechanisms ◽  
Inhaled Particles ◽  
Human Airways ◽  
Inhaled Medication

Inhalers are hand-held devices which are used for administration of therapeutic aerosols via inhalation. Nebulizers are larger devices serving for home and hospital care using inhaled medication. This contribution describes the basic principles of dispersion of aerosol particles used in various types of inhalers and nebulizers, and lists the basic physical mechanisms contributing to the deposition of inhaled particles in the human airways. The second part of this article presents experimental setup, methodology and preliminary results of particle size distributions produced by several selected inhalers and nebulizers.

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