In a healthy human, the airway mucus forms a thin, protective liquid layer covering the surface of the respiratory tract. It comprises a complex blend of mucin, multiple antibacterial proteins, metabolic substances, water, and electrolytes. This mucus plays a pivotal role in the lungs' innate immune system by maintaining airway hydration and capturing airborne particles and pathogens. However, heightened mucus secretion in the airway can compromise ciliary clearance, obstruct the respiratory tract, and increase the risk of pathogen colonization and recurrent infections. Consequently, a thorough exploration of the mechanisms driving excessive airway mucus secretion is crucial for establishing a theoretical foundation for the eventual development of targeted drugs designed to reduce mucus production. Across a range of lung diseases, excessive airway mucus secretion manifests with unique characteristics and regulatory mechanisms, all intricately linked to mucin. This article provides a comprehensive overview of the characteristics and regulatory mechanisms associated with excessive airway mucus secretion in several prevalent lung diseases.
Humans ; Mucus/metabolism* ; Mucins/physiology* ; Lung Diseases/metabolism* ; Respiratory Mucosa/metabolism* ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Asthma/physiopathology* ; Cystic Fibrosis/physiopathology* ; Mucociliary Clearance/physiology*

Disruption of normal secretion or mucociliary clearance can impair airway defense mechanisms and lung function, and increase the risk of infection. Airway clearance techniques are recommended as part of a comprehensive treatment plan for patients. Among these, vibratory expectoration is an important method of airway clearance, which loosens and liquefies mucus and metabolites on the surface of the respiratory tract through chest wall oscillation, promoting ciliary movement to facilitate sputum expulsion. However, commonly used handheld vibrating head devices and vest-type vibration expectorators have several limitations in clinical practice, such as inconvenience of operation, limited treatment time, poor adaptability, and difficulty in disinfection. To address these issues, the research team from the department of critical care medicine at Ruijin Hospital, Shanghai Jiao Tong University, has designed a novel belt-type vibration expectorator, which has been granted a national utility model patent (Patent No.: ZL 2023 2 1610983.1). The device is mainly composed of a chest strap assembly, a sputum clearance component, and a fixed shoulder strap component. Several pockets are placed on the outer surface of the chest strap, with corresponding inner-side openings that allow the percussion head of the percussive expectorator placed inside the pocket to make contact with the patient's chest wall. Each pocket has markings indicating the percussion position, enabling the placement of the percussive expectorator according to the location of infection, thereby achieving multi-point, precise percussive vibration expectoration in different body positions. On the inner side of the chest strap, there are diagrams illustrating postural drainage, providing guidance on the body positions patients should assume based on the location of infection. The hook-and-loop fasteners on both sides of the chest strap can be wrapped around and secured according to the patient's body shape, ensuring that the sputum clearance components adhere tightly to the chest wall, allowing the vibrations generated by percussion to be effectively transmitted to the patient's airways. Additionally, to prevent the chest strap from slipping due to changes in the patient's position, a Y-shaped fixing strap can be selectively attached to the chest strap for further stabilization. This innovation not only simplifies the operation process, improves convenience and flexibility of use, but also supports the principle of "disinfection after each use by one person," which helps to reduce the risk of nosocomial infections and improve the efficiency of patients' respiratory rehabilitation.
Humans ; Vibration ; Equipment Design ; Chest Wall Oscillation/instrumentation* ; Sputum ; Expectorants ; Mucociliary Clearance

Mucociliary clearance system is the primary innate defense mechanism of the lung. It plays a vital role in protecting airways from microbes and irritants infection. Mucociliary clearance system, which is mediated by the actions of airway and submucosal gland epithelial cells, plays a critical role in a multilayered defense system via secreting fluids, electrolytes, antimicrobial and anti-inflammatory proteins, and mucus onto airway surfaces. Changes in environment, drugs or diseases can lead to mucus overproduction and cilia dysfunction, which in turn decrease the rate of mucociliary clearance and enhance mucus gathering. The dysfunction of mucociliary clearance system often occurs in several respiratory diseases, such as primary ciliary dysfunction, cystic fibrosis, asthma and chronic obstructive pulmonary disease, which are characterized by goblet cell metaplasia, submucosal gland cell hypertrophy, mucus hypersecretion, cilia adhesion, lodging and loss, and airway obstruction.
Humans ; Mucociliary Clearance ; Respiratory Tract Diseases ; Pulmonary Disease, Chronic Obstructive/metabolism* ; Mucus/metabolism* ; Lung ; Respiratory System

Objective: To measure the nasal mucociliary clearance (NMC) time among adults residing in two Philippine communities with different air quality indices using the saccharin and methylene blue test. Methods: Design: Cross-Sectional Study. Setting: Diliman, Quezon City and Puerto Princesa, Palawan. Participantss: Fifty (50) participants, 25 residing in an urban city with fair air quality index and 25 residing in a rural province with good air quality index. Results: The mean NMC time of the urban group was 22.15±12.68 mins and was significantly longer than the NMC time of the rural group which was 5.29±2.87mins; t(48) = 6.643, p<0.0001). Conclusion Increased air pollution may be associated with significant prolongation of nasal mucociliary clearance time among urban residents with fair quality air index compared to rural residents with good quality air index.
Air Pollution ; Methylene Blue ; Mucociliary Clearance ; Environmental Pollution

Ambroxol is used in COPD and asthma to increase mucociliary clearance and regulate surfactant levels, perhaps through anti-oxidant and anti-inflammatory activities. To determine the role and effect of ambroxol in an experimental model of asthma, BALB/c mice were sensitized to ovalbumin (OVA) followed by 3 days of challenge. Airway hyperresponsiveness (AHR), lung cell composition and histology, and cytokine and protein carbonyl levels in bronchoalveolar lavage (BAL) fluid were determined. Ambroxol was administered either before the first OVA challenge or was begun after the last allergen challenge. Cytokine production levels from lung mononuclear cells (Lung MNCs) or alveolar macrophages (AM) were also determined. Administration of ambroxol prior to challenge suppressed AHR, airway eosinophilia, goblet cell metaplasia, and reduced inflammation in subepithelial regions. When given after challenge, AHR was suppressed but without effects on eosinophil numbers. Levels of IL-5 and IL-13 in BAL fluid were decreased when the drug was given prior to challenge; when given after challenge, increased levels of IL-10 and IL-12 were detected. Decreased levels of protein carbonyls were detected in BAL fluid following ambroxol treatment after challenge. In vitro, ambroxol increased levels of IL-10, IFN-γ, and IL-12 from Lung MNCs and AM, whereas IL-4, IL-5, and IL-13 production was not altered. Taken together, ambroxol was effective in preventing AHR and airway inflammation through upregulation of Th1 cytokines and protection from oxidative stress in the airways.
Ambroxol* ; Animals ; Asthma ; Bronchoalveolar Lavage ; Cytokines ; Eosinophilia ; Eosinophils ; Goblet Cells ; In Vitro Techniques ; Inflammation* ; Interleukin-10 ; Interleukin-12 ; Interleukin-13 ; Interleukin-4 ; Interleukin-5 ; Lung ; Macrophages, Alveolar ; Metaplasia ; Mice ; Models, Theoretical ; Mucociliary Clearance ; Neutrophils ; Ovalbumin ; Ovum ; Oxidative Stress ; Pulmonary Disease, Chronic Obstructive ; Up-Regulation

OBJECTIVE: To explore the clinical efficacy of functional endoscopic sinus surgery (FESS) associated with radiofrequency ablation on chronic sinusitis. METHOD: Fifty-four patients with chronic sinusitis were divided randomly into two groups: the study group and the control group, The study group received FESS associated with inferior turbinate lateral fracture and radiofrequency ablation treatment, while the control group received FESS associated with inferior turbinate lateral fracture treatment. RESULT: The SNOT-20 score, Lund-Kennedy score, mucociliary clearance time and nasal airway resistance of the patients in the two groups after treatment were significantly improved than those before treatment (P < 0.05), and the sense of nasal congestion, headache and face pain, purulent rhinorrhea, postnasal drip, and other symptoms were also relieved. After treatment, the scores of SNOT-20 and the scores of Lund-Kennedy in the study group were significantly lower than those in the control group (P < 0.05), but no significant difference was found in mucociliary clearance time between the two groups after treatment. CONCLUSION FESS associated with radiofrequency ablation surgery is safe and effective for chronic sinusitis.
Catheter Ablation ; Chronic Disease ; Endoscopy ; Humans ; Mucociliary Clearance ; Rhinitis ; surgery ; Sinusitis ; surgery ; Turbinates ; surgery

OBJECTIVE: To investigate the ultrastructural changes of the mucosa of eustachian tube in mice and to reveals the influence of eustachian tube on middle ear function and its relavence with otitis media. METHOD: 12 wild type and 12 mutant mice were divided into two groups by age to observe the the ultrastructural changes of the mucosa of eustachian tube. RESULT: Wild type mice exhibited a thick lawn of morphologically normal, distributed cilia in the mucosa of the middle ear at both time points. The cilia of mucosa of middle ear in mutant mice were short, impaired and disrupted. The impairment of the cilia progressed to a much great severity at 6 months compared to 3 months. CONCLUSION Otitis media occurs not only the ciliated cells decreased and the goblet cells increased. More importantly, the ciliary structure was damaged, leading to the dysfunction of the mucociliary transport system and causing otitis media.
Animals ; Cilia ; pathology ; ultrastructure ; Disease Models, Animal ; Ear, Middle ; pathology ; Eustachian Tube ; pathology ; ultrastructure ; Goblet Cells ; Mice ; Microscopy, Electron, Scanning ; Mucociliary Clearance ; Mucous Membrane ; pathology ; ultrastructure ; Otitis Media ; pathology

Primary ciliary dyskinesia (PCD) is characterized by the congenital impairment of mucociliary clearance. When accompanied by situs inversus, chronic sinusitis and bronchiectasis, PCD is known as Kartagener syndrome. The main consequence of impaired ciliary function is a reduced mucus clearance from the lungs, and susceptibility to chronic respiratory infections due to opportunistic pathogens, including nontuberculous mycobacteria (NTM). There has been no report of NTM lung disease combined with Kartagener syndrome in Korea. Here, we report an adult patient with Kartagener syndrome complicated with Mycobacterium abscessus lung disease. A 37-year-old female presented to our hospital with chronic cough and sputum. She was ultimately diagnosed with M. abscessus lung disease and Kartagener syndrome. M. abscessus was repeatedly isolated from sputum specimens collected from the patient, despite prolonged antibiotic treatment. The patient's condition improved and negative sputum culture conversion was achieved after sequential bilateral pulmonary resection.
Adult ; Bronchiectasis ; Cough ; Female ; Humans ; Kartagener Syndrome* ; Korea ; Lung ; Lung Diseases* ; Mucociliary Clearance ; Mucus ; Mycobacterium Infections, Nontuberculous ; Mycobacterium* ; Nontuberculous Mycobacteria ; Respiratory Tract Infections ; Sinusitis ; Situs Inversus ; Sputum

A 28-year-old male patient with a history of cystic fibrosis (CF) was referred to the University of Connecticut School of Dental Medicine for an evaluation of a cystic lesion in the right maxilla using cone-beam computed tomography (CBCT). CF is an autosomal recessive disease characterized by an abnormal production of viscous mucus, affecting the mucociliary clearance. The CBCT scan revealed a large cystic lesion in the right maxilla extending from the right maxillary second molar to the midline in the region of the right central incisor with a significant buccal expansion. Further evaluation revealed complete opacification of the paranasal sinuses with medial bulging of the lateral maxillary sinus walls. The maxillary and sphenoid sinuses also appeared hypoplastic. The peculiar finding seen in this case was the presence of marked sclerosis and an increase in the thickness of the adjacent bony framework. This report aimed to describe the common sinonasal findings associated with CF and its underlying pathophysiology.
Adult ; Cone-Beam Computed Tomography ; Connecticut ; Cystic Fibrosis* ; Humans ; Incisor ; Male ; Maxilla ; Maxillary Sinus ; Molar ; Mucociliary Clearance ; Mucus ; Osteitis ; Paranasal Sinuses ; Sclerosis ; Sinusitis ; Sphenoid Sinus

Submucosal glands produce most of nasal mucous secretion which play an important role in airflow hydration, mucociliary transport, innate immunity and antimicrobial defense. However, excessive mucus secretion is related with pathophysiologic characteristics in several chronic inflammatory diseases such as chronic rhinosinusitis and allergic rhinitis. This review details the anatomy, physiology of submucosal gland in nose and summarized pathophysiologic relationship between the submucosal gland and nasal diseases.
Immunity, Innate ; Mucociliary Clearance ; Mucus ; Nose Diseases ; Nose* ; Physiology ; Rhinitis