scholarly journals Mucus Clearance in Cystic Fibrosis♦

2006 ◽  
Vol 281 (11) ◽  
pp. e99904
Keyword(s):  
Cystic Fibrosis ◽  
Mucus Clearance

scholarly journals Effects of exercise and airway clearance (positive expiratory pressure) on mucus clearance in cystic fibrosis: a randomised crossover trial

2019 ◽  
Vol 53 (4) ◽  
pp. 1801793 ◽  
Author(s):  
Tiffany J. Dwyer ◽  
Evangelia Daviskas ◽  
Rahizan Zainuldin ◽  
Jordan Verschuer ◽  
Stefan Eberl ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Disease ◽  
Crossover Trial ◽  
Treadmill Exercise ◽  
Forced Expiratory Volume ◽  
Mean Difference ◽  
Peak Oxygen Consumption ◽  
Mucus Clearance ◽  
Airway Clearance ◽  
Positive Expiratory Pressure

Exercise improves mucus clearance in people without lung disease and those with chronic bronchitis. No study has investigated exercise alone for mucus clearance in cystic fibrosis (CF). The aim of this study was to compare the effects of treadmill exercise to resting breathing and airway clearance with positive expiratory pressure (PEP) therapy on mucus clearance in adults with CF.This 3-day randomised, controlled, crossover trial included 14 adults with mild to severe CF lung disease (forced expiratory volume in 1 s % predicted 31–113%). Interventions were 20 min of resting breathing (control), treadmill exercise at 60% of the participant's peak oxygen consumption or PEP therapy (including huffing and coughing). Mucus clearance was measured using the radioaerosol technique and gamma camera imaging.Treadmill exercise improved whole lung mucus clearance compared to resting breathing (mean difference 3%, 95% CI 2–4); however, exercise alone was less effective than PEP therapy (mean difference −7%, 95% CI −6– −8). When comparing treadmill exercise to PEP therapy, there were no significant differences in mucus clearance from the intermediate and peripheral lung regions, but significantly less clearance from the central lung region (likely reflecting the huffing and coughing that was only in PEP therapy).It is recommended that huffing and coughing are included to maximise mucus clearance with exercise.

scholarly journals The effect of inhaled mannitol on bronchial mucus clearance in cystic fibrosis patients: a pilot study

1999 ◽  
Vol 14 (3) ◽  
pp. 678 ◽  
Author(s):  
M. Robinson ◽  
E. Daviskas ◽  
S. Eberl ◽  
J. Baker ◽  
H-K Chan ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pilot Study ◽  
Mucus Clearance ◽  
Bronchial Mucus

Mucus clearance: in vivo canine tracheal vs. in vitro bullfrog palate studies

1977 ◽  
Vol 42 (5) ◽  
pp. 761-766 ◽  
Author(s):  
A. Giordano ◽  
C. K. Shih ◽  
D. S. Holsclaw ◽  
M. A. Khan ◽  
M. Litt
Keyword(s):  
Cystic Fibrosis ◽  
Mucociliary Clearance ◽  
Objective Method ◽  
Flow Properties ◽  
Therapeutic Modalities ◽  
Mucus Clearance ◽  
Clearance Studies ◽  
Frog Palate

Tracheal mucociliary clearance was studied by a radioisotope technique in pentothal-anesthetized beagles in the control, atropinized, or dehydrated state. Mucus collected from a tracheal pouch in each dog was used for in vitro bullfrog (Rana cantesbiana) palate clearance studies and compared to the in vivo clearance rates. In all three experimental states, there was a significant correlation between in vivo and in vitro rates, suggesting that tracheal pouch mucus is a good model for investigating the mucociliary flow properties of intact airway mucus. When compared to matched controls, atropine appeared to cause a slowing of the in vivo clearance rate but not of the in vitro rate. Dehydration had no effect on either. The appropriateness of the frog palate method in the study of human respiratory disease (e.g., chronic bronchitis, cystic fibrosis) as well as its potential as an objective method of assessing the effects of various therapeutic modalities in these diseases is discussed.

Mucus Clearance: An Experimental and Numerical Study

2011 ◽  
Author(s):  
Yingying Hu ◽  
Shiyao Bian ◽  
James B. Grotberg
Keyword(s):  
Cystic Fibrosis ◽  
Human Lung ◽  
Numerical Study ◽  
Bacterial Overgrowth ◽  
Great Difficulty ◽  
Mucus Layer ◽  
First Line ◽  
Mucus Clearance ◽  
Ciliary Function ◽  
Patients Experience

Mucus in a human lung has non-Newtonian properties such as shear-thinning, yield stress, and viscoelasticity. Rheological changes of mucus may greatly affect its ability to function as a lubricant, selective barrier, and the body’s first line of defense against infection (Lai 2009). Patients with COPD, asthma, or cystic fibrosis often have mucus hyper-secretion. Mucus plugging can cause total airway obstruction (Kant 2007). If mucus is too thick, for example in severe bronchitis or cystic fibrosis where the sputum viscosity can be more than 105 times that of water, patients experience great difficulty in mucus clearance, resulting in bacterial overgrowth (Lai 2009). The understanding of the mechanisms involved in mucus clearance is far from complete. For instance, the relation is not known between the non-Newtonian properties of the mucus layer and ciliary function in thickened mucus (Button 2008).

scholarly journals The Role of Serine Proteases and Antiproteases in the Cystic Fibrosis Lung

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Matthew S. Twigg ◽  
Simon Brockbank ◽  
Philip Lowry ◽  
S. Peter FitzGerald ◽  
Clifford Taggart ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Immune Responses ◽  
Lung Disease ◽  
Healthy Individual ◽  
Chronic Infection ◽  
Serine Proteases ◽  
High Concentration ◽  
Mucus Clearance ◽  
Potential Therapeutics

Cystic fibrosis (CF) lung disease is an inherited condition with an incidence rate of approximately 1 in 2500 new born babies. CF is characterized as chronic infection of the lung which leads to inflammation of the airway. Sputum from CF patients contains elevated levels of neutrophils and subsequently elevated levels of neutrophil serine proteases. In a healthy individual these proteases aid in the phagocytic process by degrading microbial peptides and are kept in homeostatic balance by cognate antiproteases. Due to the heavy neutrophil burden associated with CF the high concentration of neutrophil derived proteases overwhelms cognate antiproteases. The general effects of this protease/antiprotease imbalance are impaired mucus clearance, increased and self-perpetuating inflammation, and impaired immune responses and tissue. To restore this balance antiproteases have been suggested as potential therapeutics or therapeutic targets. As such a number of both endogenous and synthetic antiproteases have been trialed with mixed success as therapeutics for CF lung disease.

scholarly journals Combined agonists act synergistically to increase mucociliary clearance in a cystic fibrosis airway model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nam Soo Joo ◽  
Hyung-Ju Cho ◽  
Meagan Shinbashi ◽  
Jae Young Choi ◽  
Carlos E. Milla ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Mucociliary Clearance ◽  
Defense Mechanism ◽  
Fluid Secretion ◽  
Adrenergic Agonist ◽  
Anion Secretion ◽  
Innate Defense ◽  
Mucus Clearance ◽  
Cystic Fibrosis Airway ◽  
Submucosal Glands

AbstractMucus clearance, a primary innate defense mechanism of airways, is defective in patients with cystic fibrosis (CF) and CF animals. In previous work, the combination of a low dose of the cholinergic agonist, carbachol with forskolin or a β adrenergic agonist, isoproterenol synergistically increased mucociliary clearance velocity (MCCV) in ferret tracheas. Importantly, the present study shows that synergistic MCCV can also be produced in CF ferrets, with increases ~ 55% of WT. Synergistic MCCV was also produced in pigs. The combined agonists increased MCCV by increasing surface fluid via multiple mechanisms: increased fluid secretion from submucosal glands, increased anion secretion across surface epithelia and decreased Na+ absorption. To avoid bronchoconstriction, the cAMP agonist was applied 30 min before carbachol. This approach to increasing mucus clearance warrants testing for safety and efficacy in humans as a potential therapeutic for muco-obstructive diseases.

Effects of Gravity on Tracheal Mucus Transport Rates in Normal Subjects and in Patients With Cystic Fibrosis

PEDIATRICS ◽  
1977 ◽  
Vol 60 (2) ◽  
pp. 146-152
Author(s):  
John W. Wong ◽  
Thomas G. Keens ◽  
Eleanor M. Wannamaker ◽  
Douglas N. Crozier ◽  
Henry Levison ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Normal Subjects ◽  
Major Influence ◽  
Upper Respiratory Tract ◽  
Mucus Clearance ◽  
Effective Form ◽  
Postural Drainage ◽  
Significant Difference ◽  
The Subject ◽  
Tracheal Mucus

A noninvasive, radionuclide imaging technique for measuring the rate of mucus clearance in the trachea (RT), was used to study gravitational effects on mucus clearance in 13 patients with cystic fibrosis (CF), average age 17 years; 7 normal, nonsmoking adults, average age 26 years; and a normal subject who was recovering from an acute upper respiratory tract infection (URTI). In the upright position, nine of the CF patients and the subject with URTI demonstrated abnormal tracheal mucus clearance which approached normal when they were placed in a 25° headdown position. The normal subjects and two of the CF patients showed no significant difference in the RT measured in the two positions. The results of the study indicate that the force of gravity can be a major influence on tracheal mucus clearance in CF and URTI subjects. This conclusion supports the use of postural drainage as an effective form of therapy in patients with cystic fibrosis.

scholarly journals Acinar origin of CFTR-dependent airway submucosal gland fluid secretion

2007 ◽  
Vol 292 (1) ◽  
pp. L304-L311 ◽  
Author(s):  
Jin V. Wu ◽  
Mauri E. Krouse ◽  
Jeffrey J. Wine
Keyword(s):  
Cystic Fibrosis ◽  
Fluid Secretion ◽  
Time Lapse ◽  
Airway Disease ◽  
Bulk Flow ◽  
Submucosal Gland ◽  
Mucus Clearance ◽  
Submucosal Glands ◽  
Gland Duct ◽  
Time Lapse Imaging

Cystic fibrosis (CF) airway disease arises from defective innate defenses, especially defective mucus clearance of microorganisms. Airway submucosal glands secrete most airway mucus, and CF airway glands do not secrete in response to VIP or forskolin. CFTR, the protein that is defective in CF, is expressed in glands, but immunocytochemistry finds the highest expression of CFTR in either the ciliated ducts or in the acini, depending on the antibodies used. CFTR is absolutely required for forskolin-mediated gland secretion; we used this finding to localize the origin of forskolin-stimulated, CFTR-dependent gland fluid secretion. We tested the hypothesis that secretion to forskolin might originate from the gland duct rather than or in addition to the acini. We ligated gland ducts at various points, stimulated the glands with forskolin, and monitored the regions of the glands that swelled. The results supported an acinar rather than ductal origin of secretion. We tracked particles in the mucus using Nomarski time-lapse imaging; particles originated in the acini and traveled toward the duct orifice. Estimated bulk flow accelerated in the acini and mucus tubules, consistent with fluid secretion in those regions, but was constant in the unbranched duct, consistent with a lack of fluid secretion or absorption by the ductal epithelium. We conclude that CFTR-dependent gland fluid secretion originates in the serous acini. The failure to observe either secretion or absorption from the CFTR and epithelial Na+ channel (ENaC)-rich ciliated ducts is unexplained, but may indicate that this epithelium alters the composition rather than the volume of gland mucus.

scholarly journals Pathological mucus and impaired mucus clearance in cystic fibrosis patients result from increased concentration, not altered pH

2018 ◽  
Vol 52 (6) ◽  
pp. 1801297 ◽  
Author(s):  
David B. Hill ◽  
Robert F. Long ◽  
William J. Kissner ◽  
Eyad Atieh ◽  
Ian C. Garbarine ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Disulfide Bonds ◽  
Chemical Reduction ◽  
Length Scales ◽  
Mucus Clearance ◽  
Alternative Hypotheses ◽  
Series Of Experiments ◽  
Airway Mucus ◽  
Water Secretion ◽  
Airway Acidification

Cystic fibrosis (CF) is a recessive genetic disease that is characterised by airway mucus plugging and reduced mucus clearance. There are currently alternative hypotheses that attempt to describe the abnormally viscous and elastic mucus that is a hallmark of CF airways disease, including: 1) loss of CF transmembrane regulator (CFTR)-dependent airway surface volume (water) secretion, producing mucus hyperconcentration-dependent increased viscosity, and 2) impaired bicarbonate secretion by CFTR, producing acidification of airway surfaces and increased mucus viscosity.A series of experiments was conducted to determine the contributions of mucus concentration versus pH to the rheological properties of airway mucus across length scales from the nanoscopic to macroscopic.For length scales greater than the nanoscopic, i.e. those relevant to mucociliary clearance, the effect of mucus concentration dominated over the effect of airway acidification.Mucus hydration and chemical reduction of disulfide bonds that connect mucin monomers are more promising therapeutic approaches than alkalisation.

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