[Complete Disruption of the Left Main Bronchus Treated with Extracorporeal Membrane Oxygenation Support and Pneumonectomy].

A 60-year old woman, sandwiched between two boats was brought to our hospital with severe respiratory failure. She was in pre-shock and there was extensive cutaneous emphysema from the face to abdomen. She required respirator support and bilateral chest tubes for hemopneumothorax. On the patient's 3rd hospital day, she received venovenous extracorporeal membrance oxgenation( ECMO) due to sudden ventilatory failure. The bronchofiberscopy revealed complete disruption of the left main bronchus and occlusion of the right one owing to blood clot and sputum. Because of significant destruction of the left main bronchus, we didn't attempt bronchoplasty, and performed left pneumonectomy under veno-venous (VV)-ECMO. The postoperative course was uneventful, and she was discharged after 30 days with satisfactory outcome.

[Management of Tracheobronchial Injuries due to Brunt Trauma].

BACKGROUND: Tracheobronchial injuries resulting from blunt trauma are relatively rare among chest injuries. However, if these injuries are not managed properly, they can be fatal. The prognosis is intricately linked to the precise diagnosis and treatment. We herein report three cases of tracheobronchial trauma that required surgical intervention. Case 1:A 17-year-old male sustained injuries when his torso became entangled in heavy machinery. The diagnosis revealed a tear in the right main bronchus, which required transportation with left single- lung ventilation. The patient was treated by tracheobronchial reconstruction. Case 2:A 71-year-old male experienced trauma when his car collided with a utility pole. He was transported to the hospital after tracheal intubation due to a laceration of the tracheal membranous area. The site of the injury was closed with sutures. Case 3:A 17-year-old female who had been struck by a train suffered acute respiratory failure and was transported to the hospital after intubation. Veno-venous extracorporeal membrane oxgenation (VV-ECMO) was initiated in response to poor oxygenation. Complete rupture of the right middle bronchial trunk and laceration of the right main bronchial membrane were observed, and bronchoplasty was performed. CONCLUSION: A swift and accurate diagnosis, coupled with timely and judicious therapeutic interventions, play a pivotal role in managing tracheal and bronchial injuries.

Clinical characteristics and removal approaches of tracheal and bronchial foreign bodies in elders.

The symptoms of tracheobronchial foreign body in the elderly are not typical, so they are often missed or misdiagnosed. This study aims to depict the clinical characteristics of tracheobronchial foreign body inhalation in the elderly. We retrospectively analysed the clinical data of elder patients (age ≥ 65 years) diagnosed with tracheal and bronchial foreign bodies. The data included age, sex, clinical symptoms, type and location of foreign bodies, prehospital duration, Chest CT, bronchoscopic findings, and frequencies and tools for removing these elderly patients' tracheal and bronchial foreign bodies. All patients were followed up for a half year. Fifty-nine cases were included, of which only 32.2% had a definite aspiration history. Disease duration > 30 days accounted for 27.1% of the patients. 27.1% of the patients had a history of stroke, and 23.8% had Alzheimer's Disease. Regarding clinical symptoms, patients mainly experience cough and expectoration. The most common CT findings were abnormal density shadow (37.3%) and pulmonary infiltration (22.0%). Under bronchoscopy, purulent secretions were observed in 52.5% of patients, and granulation tissue hyperplasia was observed in 45.8%. Food (55.9%) was the most common foreign object, including seafood shells (5.1%), bones (20.3%), dentures (18.6%), and tablets (20.3%). The success rate of foreign body removal under a bronchoscope was 96.7%, 28.8% of the foreign bodies were on the left and 69.5% on the right. 5.1% of the elderly patients required rigid bronchoscopy, and 6.8% required two bronchoscopies. In elderly cohorts, tracheal foreign bodies are obscured by nonspecific clinical presentations and a paucity of aspiration history, challenging timely diagnosis. Predominantly constituted by food particles, with a notable predilection for the left bronchial tree, these cases demand skilled bronchoscopic management, occasionally requiring sophisticated approaches for successful extraction.

Protecting the non-operative lobe/s of the operative lung can reduce the pneumonia incidence after thoracoscopic lobectomy: a randomised controlled trial.

Lung isolation usually refers to the isolation of the operative from the non-operative lung without isolating the non-operative lobe(s) of the operative lung. We aimed to evaluate whether protecting the non-operative lobe of the operative lung using a double-bronchial blocker (DBB) with continuous positive airway pressure (CPAP) could reduce the incidence of postoperative pneumonia. Eighty patients were randomly divided into two groups (n = 40 each): the DBB with CPAP (Group DBB) and routine bronchial blocker (Group BB) groups. In Group DBB, a 7-Fr BB was placed in the middle bronchus of the right lung for right lung surgery and in the inferior lobar bronchus of the left lung for left lung surgery. Further, a 9-Fr BB was placed in the main bronchus of the operative lung. In Group BB, routine BB placement was performed on the main bronchus on the surgical side. The primary endpoint was the postoperative pneumonia incidence. Compared with Group BB, Group DBB had a significantly lower postoperative pneumonia incidence in the operative (27.5% vs 5%, P = 0.013) and non-operative lung (40% vs 15%) on postoperative day 1. Compared with routine BB use for thoracoscopic lobectomy, using the DBB technique to isolate the operative lobe from the non-operative lobe(s) of the operative lung and providing CPAP to the non-operative lobe(s) through a BB can reduce the incidence of postoperative pneumonia in the operative and non-operative lungs.

Bronchoconstriction damages airway epithelia by crowding-induced excess cell extrusion.

Asthma is deemed an inflammatory disease, yet the defining diagnostic feature is mechanical bronchoconstriction. We previously discovered a conserved process called cell extrusion that drives homeostatic epithelial cell death when cells become too crowded. In this work, we show that the pathological crowding of a bronchoconstrictive attack causes so much epithelial cell extrusion that it damages the airways, resulting in inflammation and mucus secretion in both mice and humans. Although relaxing the airways with the rescue treatment albuterol did not affect these responses, inhibiting live cell extrusion signaling during bronchoconstriction prevented all these features. Our findings show that bronchoconstriction causes epithelial damage and inflammation by excess crowding-induced cell extrusion and suggest that blocking epithelial extrusion, instead of the ensuing downstream inflammation, could prevent the feed-forward asthma inflammatory cycle.

Different anatomical variations in the anterior segment of the right upper lung.

During a routine physical examination three years ago, a 47-year-old woman received a diagnosis of a nodule in her right upper lung. Since then, she has been regularly attending outpatient clinic appointments for follow-up. Over time, the nodule has shown gradual growth, leading to a suspicion of lung cancer. Through the use of enhanced CT imaging, a three-dimensional reconstruction was performed to examine the bronchi and blood vessels in the patient's chest. This reconstruction revealed several variations in the anatomy of the anterior segment of the right upper lobe. Specifically, the anterior segmental bronchus (B3) was found to have originated from the right middle lung bronchus. Additionally, the medial subsegmental artery of the anterior segmental artery (A3b) and the medial segmental artery (A5) were observed to share a common trunk. As for the lateral subsegmental artery of the anterior segmental artery (A3a), it was found to have originated from the right inferior pulmonary trunk. Furthermore, the apical subsegmental artery of the apical segmental artery (A1a) and the posterior segmental artery (A2) were found to have a shared trunk.

Case study observational research: inflammatory cytokines in the bronchial epithelial lining fluid of COVID-19 patients with acute hypoxemic respiratory failure.

BACKGROUND: In this study, the concentrations of inflammatory cytokines were measured in the bronchial epithelial lining fluid (ELF) and plasma in patients with acute hypoxemic respiratory failure (AHRF) secondary to severe coronavirus disease 2019 (COVID-19). METHODS: We comprehensively analyzed the concentrations of 25 cytokines in the ELF and plasma of 27 COVID-19 AHRF patients. ELF was collected using the bronchial microsampling method through an endotracheal tube just after patients were intubated for mechanical ventilation. RESULTS: Compared with those in healthy volunteers, the concentrations of interleukin (IL)-6 (median 27.6 pmol/L), IL-8 (1045.1 pmol/L), IL-17A (0.8 pmol/L), IL-25 (1.5 pmol/L), and IL-31 (42.3 pmol/L) were significantly greater in the ELF of COVID-19 patients than in that of volunteers. The concentrations of MCP-1 and MIP-1ß were significantly greater in the plasma of COVID-19 patients than in that of volunteers. The ELF/plasma ratio of IL-8 was the highest among the 25 cytokines, with a median of 737, and the ELF/plasma ratio of IL-6 (median: 218), IL-1ß (202), IL-31 (169), MCP-1 (81), MIP-1ß (55), and TNF-α (47) were lower. CONCLUSIONS: The ELF concentrations of IL-6, IL-8, IL-17A, IL-25, and IL-31 were significantly increased in COVID-19 patients. Although high levels of MIP-1 and MIP-1ß were also detected in the blood samples collected simultaneously with the ELF samples, the results indicated that lung inflammation was highly compartmentalized. Our study demonstrated that a comprehensive analysis of cytokines in the ELF is a feasible approach for understanding lung inflammation and systemic interactions in patients with severe pneumonia.

Differential beta-coronavirus infection dynamics in human bronchial epithelial organoids.

The lower respiratory system serves as the target and barrier for beta-coronavirus (beta-CoV) infections. In this study, we explored beta-CoV infection dynamics in human bronchial epithelial (HBE) organoids, focusing on HCoV-OC43, SARS-CoV, MERS-CoV, and SARS-CoV-2. Utilizing advanced organoid culture techniques, we observed robust replication for all beta-CoVs, particularly noting that SARS-CoV-2 reached peak viral RNA levels at 72 h postinfection. Through comprehensive transcriptomic analysis, we identified significant shifts in cell population dynamics, marked by an increase in goblet cells and a concurrent decrease in ciliated cells. Furthermore, our cell tropism analysis unveiled distinct preferences in viral targeting: HCoV-OC43 predominantly infected club cells, while SARS-CoV had a dual tropism for goblet and ciliated cells. In contrast, SARS-CoV-2 primarily infected ciliated cells, and MERS-CoV showed a marked affinity for goblet cells. Host factor analysis revealed the upregulation of genes encoding viral receptors and proteases. Notably, HCoV-OC43 induced the unfolded protein response pathway, which may facilitate viral replication. Our study also reveals a complex interplay between inflammatory pathways and the suppression of interferon responses during beta-CoV infections. These findings provide insights into host-virus interactions and antiviral defense mechanisms, contributing to our understanding of beta-CoV infections in the respiratory tract.

[Comparison of ultrathin bronchoscopy with conventional bronchoscopy for the diagnostic value of peripheral pulmonary lesions].

Objective: To assess and compare the diagnostic efficacy of next-generation ultrathin bronchoscopy (UTB) and conventional bronchoscopy (CB), both combined with radial endobronchial ultrasound (r-EBUS), in the evaluation of peripheral pulmonary lesions (PPL). Methods: A cohort of 39 patients with PPL who underwent multimodal bronchoscopy at Dushu Lake Hospital, Soochow University, from June 1, 2021 to May 31, 2023 was consecutively enrolled. A single bronchoscopist performed multimodal bronchoscopies using CB (external diameter 4.9 mm or 5.9 mm, working channel diameter 2 or 3 mm, CB group) for transbronchial biopsy under r-EBUS guidance (rEBUS-TBLB), followed by UTB (external diameter 3 mm, working channel diameter 1.7 mm, UTB group) for transbronchial biopsy under r-EBUS guidance. Pathological findings and a 6-month clinical follow-up were used as the gold standard to compare the diagnostic yield of biopsy specimens, ultrasound characteristics, and localization rates of the two bronchoscope types. The aim was to evaluate the clinical application value of UTB combined with r-EBUS. Binary variables were analysed using the McNemar test for paired data. Continuous variables or ranked data were analysed using the Wilcoxon signed-rank test for paired data. Results: The diagnostic yields for UTB and CB groups were 66.67% (26/39) and 30.77% (12/39), respectively, with the UTB group significantly surpassing the CB group (χ2=10.56, P=0.001, 1-ß=0.968). r-EBUS with CB exhibited no visible lesion in 13 cases, adjacent to the lesion in 19 cases, and within the lesion in 7 cases.Substitution of UTB resulted in r-EBUS images changing from no visible lesion to adjacent to the lesion in 7 cases, from no visible lesion to within the lesion in 3 cases, and from adjacent to the lesion to within the lesion in 12 cases. The positioning of the r-EBUS probe in relation to the lesions improved significantly with UTB usage (Z=-4.46, P<0.001). Localization rates (number of patients with "within" or "adjacent to" the image/total number of patients) for UTB and CB were 92.30% (36/39) and 66.67% (26/39), respectively (χ2=8.10, P=0.002). UTB improved r-EBUS probe localization rates. The diagnostic yields of UTB were higher than CB for solid lesions, lesions>30 mm in diameter, non-upper lobar location, benign or malignant lesions and lesions with or without a bronchus sign. Conclusion: The UTB group demonstrated a significantly higher diagnostic yield than the CB group, providing superior r-EBUS probe images, and a significant diagnostic advantage for PPL.

[Diffuse thickening of bronchial walls with multiple nodular mucosal protrusions].

A 58-year-old woman presented with a six-month history of nasal congestion, sore throat and cough, and a five-month history of dyspnea. She had a history of xerostomia for one year. On examination, the bilateral submandibular gland and parotid glands were enlarged. Parotid and anterior cervical lymph nodes were palpable. There were rales in both lungs. The rest of the physical examination was unremarkable. Sialographic analysis showed normal caliber in the main duct, stenosis in secondary ducts, and dilation in the proximal ducts. Minor salivary gland biopsy demonstrated periductal lymphocytic infiltration. Chest computed tomography (CT) showed diffuse thickening of the tracheal and bilateral bronchial walls. Bronchoscopy revealed macroscopic multiple nodules mainly in the trachea and bilateral main bronchus. Endobronchial biopsy showed lymphocytic infiltration in the bronchial submucosa. She was diagnosed with Sjögren's syndrome and treated with glucocorticoids. The dose of prednisone was started at 30 mg/d and tapered gradually. Following treatment, the patient's clinical condition improved dramatically, with shrinkage of the enlarged lymph nodes, bilateral submandibular and parotid glands. A repeated chest CT scan revealed improvement of the tracheal and bilateral bronchial thickening. Multiple nodules in the airway regressed, as evidenced by repeated bronchoscopic examination. The final diagnosis was a large-airway disease associated with Sjögren's syndrome.Among airway diseases in Sjögren's syndrome, peripheral airway diseases including bronchiolitis and bronchiectasis are common; however, central airway lesions in Sjögren's syndrome, especially with macroscopic nodules, are rare. In this case, we demonstrated tracheal and endobronchial nodules in Sjögren's syndrome as determined by clinical features, CT scan, bronchoscopy, and response to therapy.

Is it in their eyes? Correlation between microorganisms isolated from bronchial aspirates and conjunctival swabs in a Pediatric Intensive Care Unit / ¿Está en sus ojos? Correlación entre microorganismos aislados de aspirados bronquiales e hisopos conjuntivales en una Unidad de Cuidados Intensivos Pediátricos

Objectives. Our observational, retrospective study aimed to determine the correlation between bacteria isolated from bronchial aspirates of pediatric ICU patients (PICU) with respiratory infections and those obtained from conjunctival swabs of the same patients exhibiting clinical conjunctivitis. Material and methods. Throughout the period from 2015 to 2022, we reviewed all clinically significant bronchial aspirates (≥105 CFU/mL) and positive conjunctival swabs obtained from PICU patients. These records were retrieved from the microbiology database, cross-referencing the data to identify patients who tested positive for both during the same clinical episode. Results. The median age of the patients was 5 months (interquartile range: 1-7). Among the cohort, twenty-one patients exhibited positivity in both bronchial aspirate and conjunctival swab samples, showcasing a microbial match in 85.71% of cases (18 out of 21). The most frequently isolated microorganisms were Haemophilus influenzae (55.6%), followed by Pseudomonas aeruginosa (14.3%), Klebsiella aerogenes (9.5%), and Escherichia coli, Stenotrophomonas maltophilia, and Enterobacter cloacae, each accounting for 4.8% of the isolates. Conclusions. Our study demonstrates a strong concordance between the isolated microorganisms from both samples in patients presenting clear symptoms of clinical conjunctivitis. These findings provide a basis for future prospective studies that may leverage conjunctival swabs as a predictive tool for identifying microorganisms involved in respiratory infections. (AU)

Objetivos. Nuestro estudio observacional y retrospectivo tuvo como objetivo determinar la correlación entre las bacterias aisladas de aspirados bronquiales de pacientes de UCI pediátrica (UCIP) con infecciones respiratorias y las obtenidas de hisopos conjuntivales de los mismos pacientes que presentaban conjuntivitis clínica. Material y métodos. A lo largo del periodo comprendido entre 2015 y 2022, se revisaron todos los aspirados bronquiales clínicamente significativos (≥105 UFC/mL) y los hisopos conjuntivalespositivos obtenidos de pacientes de UCIP. Estos registros se recuperaron de la base de datos de microbiología, cruzando los datos para identificar a los pacientes que dieron positivo en ambos durante el mismo episodio clínico. Resultados. La mediana de edad de los pacientes fue de 5 meses (rango intercuartílico: 1-7). Entre la cohorte, veintiún pacientes presentaron positividad tanto en las muestras de aspirado bronquial como en las de hisopo conjuntival, mostrando una coincidencia microbiana en el 85,71% de los casos (18 de 21). Los microorganismos más frecuentemente aislados fueron Haemophilus influenzae (55,6%), seguido de Pseudomonas aeruginosa (14,3%), Klebsiella aerogenes (9,5%) y Escherichia coli, Stenotrophomonas maltophiliay Enterobacter cloacae, cada uno de los cuales representó el 4,8% de los aislamientos. Conclusiones. Nuestro estudio demuestra una fuerte concordancia entre los microorganismos aislados de ambas muestras en pacientes que presentan síntomas claros de conjuntivitis clínica. Estos hallazgos proporcionan una base para futuros estudios prospectivos que podrían aprovechar los hisopos conjuntivales como herramienta predictiva para identificar microorganismos implicados en infecciones respiratorias. (AU)

Pulmonary Function in People Living With Human Immunodeficiency Virus: A Meta-Analysis

Background: HIV can infect bronchial epithelial cells rendering individuals susceptible to lung damage. Our objective was to determine the effects of human immunodeficiency virus (HIV) infection on pulmonary function tests. Methods: We performed a meta-analysis after conducting a literature search in PubMed, Embase, Cochrane Library and Virtual Health Library databases from inception to December 31st, 2022. We employed the inverse variance method with a random effects model to calculate the effect estimate as the mean difference (MD) and 95% confidence interval (CI). We calculated the heterogeneity with the I2 statistic and performed a meta-regression analysis by age, sex, smoking, CD4 T-cells count and antiretroviral therapy. We also conducted a sensitivity analysis according to the studies’ publication date, and excluding the study with the greatest weight in the effect. The PROSPERO registry number was CRD42023401105. Results: The meta-analysis included 20 studies, with 7621 living with HIV and 7410 control participants. The pooled MD (95%CI) for the predicted percentage of FEV1, FVC and DLCO were −3.12 (−5.17, −1.06); p=0.003, −1.51 (−3.04, 0.02); p=0.05, and −5.26 (−6.64, −3.87); p<0.001, respectively. The pooled MD for FEV1/FVC was −0.01 (−0.02, −0.01); p=0.002. In all cases, there was a considerable heterogeneity. The meta-regression analysis showed that among studies heterogeneity was not explained by patient age, smoking, CD4 T-cells count or antiretroviral therapy. Conclusion: Pulmonary function tests are impaired in people living with HIV, independently of age, smoking, CD4 T-cells count, and geographical region. (AU)

[Resected Right Upper Lobe Lung Cancer with Displaced Bronchus and Anomalous Pulmonary Vein].

The patient is a 77-year-old man. He was referred to our hospital after a chest computed tomography (CT) scan revealed a 6.5 cm-sized mass in the right lung apex. Bronchoscopy revealed adenocarcinoma, clinical stageⅡB, and the patient was referred for surgery. Preoperative 3D-CT revealed the presence of a displaced bronchus, probably B1a, branching from the right main bronchus centrally from the upper lobe bronchus, and an abnormal vessel (V2) running dorsal to the upper lobe bronchus and the right main bronchus, and returning directly to the left atrium. Surgery was performed by resectioning the right upper lobe through a posterolateral incision, combined resection of the wall pleura, and lymph node dissection (ND2a-2). Because lung cancer surgery is sometimes accompanied by abnormal bronchial and pulmonary vascular branches, it is essential to thoroughly examine the patient before surgery for checking abnormal branches by bronchoscopy and 3D-CT.

[Comparison of Two Methods With a Left-Sided Double-Lumen Tube for Endobronchial Intubation].

Objective To compare the success rates of two methods for endobronchial intubation:the left-sided double-lumen tube(DLT) rotated 90° counter-clockwise with the patient head at the mid positon and the tube rotated 180° counter-clockwise with the patient head turned to the right. Methods Six hundred and forty-eight patients were enrolled in this study,who were to undergo elective thoracic surgery by left-sided DLT intubation in the Peking Union Medical College Hospital from December 2021 to June 2022.They were randomized into a 90° group and a 180° group,with 324 patients in each group.In the 90° group,with the patient head kept at the mid position,the left-sided DLT was advanced until the bronchial cuff passed the vocal cords and then rotated 90° counter-clockwise.In the 180°group,with the left mandible angle of each patient in the straight line with the sternum,the tube was advanced until the bronchial cuff passed the vocal cords and then rotated 180° counter-clockwise.The intubation success rate and the intubation-related complications such as carina mucosal injuries were compared between the two groups. Results The 648 patients included 336 males and 312 females,with the age ranging from 39.0 to 75.0 years old and the average age of(54.6±9.0) years old.The success rate of first intubation was 80.3% in the 90° group and 75.0% in the 180° group,which showed no significant difference(P=0.109).The success rate of second intubation was higher in the 180° group than in the 90° group(P<0.001).The rate of carina mucosal injuries was 23.8% in the 90° group and 25.6% in the 180° group,which showed no significant difference(P=0.585). Conclusions Compared with the conventional method(90°),the intubation of the left-sided DLT rotated 180° counter-clockwise with the patient head turned to the right cannot improve the success rate of the first intubation.However,it could improve the success rate of reintubation as a remedy.

Placement of bronchial occluder outside the tracheal tube in a patient combined with airway compression undergoing mediastinal tumors resection: a case report.

BACKGROUND: Mediastinal tumors pose a challenging respiratory and circulatory management during anesthesia procedures, there is a risk of circulatory collapse or complete airway obstruction, which in severe cases can lead to cardiac arrest. We reported a case of anesthetic management using a bronchial blocker placed outside the tracheal tube. In this case report, the patient's trachea was so severely compressed that the airway was extremely narrow, only 4 mm at its narrowest point. By reporting the anesthetic management of this patient, we intend to provide an unusual approach for airway management. CASE PRESENTATION: A 52-year-old male patient was admitted to the hospital due to cough and expectoration for one year. Additionally, the patient experienced chest tightness and asthma after physical activity. The enhanced computed tomography revealed there existed an irregular soft tissue mass in the right upper mediastinum, which significantly compressed the trachea and esophagus. The results of the mediastinal puncture pathology showed the presence of mesenchymal tumors. According to the results above, the patient was diagnosed with a mediastinal tumor and scheduled to undergo tumor resection under general anesthesia. We used a bronchial occluder outside the tracheal tube for general anesthesia. After surgery, the patient received thorough treatment and was subsequently discharged from the hospital. CONCLUSION: In patients with severe airway compression from a mediastinal tumor airway compression, positioning a bronchial occluder externally to the tracheal tube is an effective method of airway management. However, we still need more clinical practice to help the process become more standardized.

Extracellular acidification attenuates bronchial contraction via an autocrine activation of EP2 receptor: Its diminishment in murine experimental asthma.

PURPOSE: Extracellular acidification is a major component of tissue inflammation, including airway inflammation in asthmatics. However, its physiological/pathophysiological significance in bronchial function is not fully understood. Currently, the functional role of extracellular acidification on bronchial contraction was explored. METHODS: Left main bronchi were isolated from male BALB/c mice. Epithelium-removed tissues were exposed to acidic pH under submaximal contraction induced by 10-5 M acetylcholine in the presence or absence of a COX inhibitor indomethacin (10-6 M). Effects of AH6809 (10-6 M, an EP2 receptor antagonist), BW A868C (10-7 M, a DP receptor antagonist) and CAY10441 (3×10-6 M, an IP receptor antagonist) on the acidification-induced change in tension were determined. The release of prostaglandin E2 (PGE2) from epithelium-denuded tissues in response to acidic pH was assessed using an ELISA. RESULTS: In the bronchi stimulated with acetylcholine, change in the extracellular pH from 7.4 to 6.8 caused a transient augmentation of contraction followed by a sustained relaxing response. The latter inhibitory response was abolished by indomethacin and AH6809 but not by BW A868C or CAY10441. Both indomethacin and AH6809 significantly increased potency and efficacy of acetylcholine at pH 6.8. Stimulation with low pH caused an increase in PGE2 release from epithelium-denuded bronchi. Interestingly, the acidic pH-induced bronchial relaxation was significantly reduced in a murine asthma model that had a bronchial hyperresponsiveness to acetylcholine. CONCLUSION: Taken together, extracellular acidification could inhibit the bronchial contraction via autocrine activation of EP2 receptors. The diminished acidic pH-mediated inhibition of bronchial tone may contribute to excessive bronchoconstriction in inflamed airways such as asthma.

Comparing region of interest selection and whole-field analysis for measurement of ciliary beat frequency in high-speed video analysis.

BACKGROUND: Ciliary beat frequency (CBF) is crucial in mucociliary clearance. High-speed video analysis (HSVA) is commonly used to measure CBF but lacks standardization. We compared visual observation and computer-assisted calculation using fast Fourier transformation (FFT) in freshly collected bronchial ciliary epithelial cells and cultured cells. METHODS: Bronchial epithelial cells were obtained from 12 patients who required bronchoscopic examination. Eighty-five videos of ciliary movement of freshly collected and cultured cells were recorded and used to calculate CBF using manual observation, region of interest (ROI) selection, and whole-field analysis. RESULTS: CBF measured by the ROI selection method strongly correlated with that measured using manual observation, especially in freshly collected cells. However, 27.8% of the manual observation method values were doubled in the ROI selection method, probably because a round trip of cilia was calculated as two cycles and needed to be corrected to 1/2 value. Upon increasing the number of ROIs, the results of the ROI selection method came closer to that of WFA. CONCLUSIONS: Computer-assisted calculation using FFT can aid in measuring CBF; however, current methods require visual confirmation. Further automated evaluation techniques are needed to establish more standardized and generalized CBF measurement methods using HSVA.