Chemosensory Cell-Derived Acetylcholine Drives Tracheal Mucociliary Clearance in Response to Virulence-Associated Formyl Peptides.

Mucociliary clearance through coordinated ciliary beating is a major innate defense removing pathogens from the lower airways, but the pathogen sensing and downstream signaling mechanisms remain unclear. We identified virulence-associated formylated bacterial peptides that potently stimulated ciliary-driven transport in the mouse trachea. This innate response was independent of formyl peptide and taste receptors but depended on key taste transduction genes. Tracheal cholinergic chemosensory cells expressed these genes, and genetic ablation of these cells abrogated peptide-driven stimulation of mucociliary clearance. Trpm5-deficient mice were more susceptible to infection with a natural pathogen, and formylated bacterial peptides were detected in patients with chronic obstructive pulmonary disease. Optogenetics and peptide stimulation revealed that ciliary beating was driven by paracrine cholinergic signaling from chemosensory to ciliated cells operating through muscarinic M3 receptors independently of nerves. We provide a cellular and molecular framework that defines how tracheal chemosensory cells integrate chemosensation with innate defense.

Obesity impairs ciliary function and mucociliary clearance in the murine airway epithelium.

Obesity is a risk factor for increased morbidity and mortality in viral respiratory infection. Mucociliary clearance (MCC) in the airway is the primary host defense against viral infections. However, the impact of obesity on MCC is unclear, prompting this study. Using murine tracheal tissue culture and in vitro influenza A virus (IAV) infection models, we analyzed cilia-driven flow and ciliary beat frequency (CBF) in the airway epithelium to evaluate MCC. Short-term IAV infection increased cilia-driven flow and CBF in control mice, but not in high-fat diet-induced obese mice. Basal cilia-driven flow and CBF were also lower in obese mice than in control mice. Mechanistically, the increase of extracellular adenosine triphosphate (ATP) release during IAV infection, which was observed in the control mice, was abolished in the obese mice; however, the addition of ATP increased cilia-driven flow and CBF both in control and obese mice to a similar extent. In addition, RNA sequencing and reverse transcription-polymerase chain reaction revealed the downregulation of several cilia-related genes, including Dnah1, Dnal1, Armc4, and Ttc12 (the dynein-related genes); Ulk4 (the polychaete differentiation gene); Cep164 (the ciliogenesis and intraflagellar transport gene); Rsph4a, Cfap206, and Ppil6 (the radial spoke structure and assembly gene); and Drc3(the nexin-dynein regulatory complex genes) in obese murine tracheal tissues compared with their control levels. In conclusion, our studies demonstrate that obesity attenuates MCC under basal conditions and during IAV infection by downregulating the expression of cilia-related genes and suppressing the release of extracellular ATP, thereby increasing the susceptibility and severity of IAV infection.NEW & NOTEWORTHY Our study shows that obesity impairs airway mucociliary clearance (MCC), an essential physical innate defense mechanism for viral infection. Mechanically, this is likely due to the obesity-induced downregulation of cilia-related genes and attenuation of extracellular ATP release. This study provides novel insights into the mechanisms driving the higher susceptibility and severity of viral respiratory infections in individuals with obesity.

Airway disease decreases the therapeutic potential of epithelial stem cells.

BACKGORUND: Tissue-engineered tracheal grafts (TETG) can be recellularized by the host or pre-seeded with host-derived cells. However, the impact of airway disease on the recellularization process is unknown. METHODS: In this study, we determined if airway disease alters the regenerative potential of the human tracheobronchial epithelium (hTBE) obtained by brushing the tracheal mucosa during clinically-indicated bronchoscopy from 48 pediatric and six adult patients. RESULTS: Our findings revealed that basal cell recovery and frequency did not vary by age or region. At passage 1, all samples produced enough cells to cellularize a 3.5 by 0.5 cm2 graft scaffold at low cell density (~ 7000 cells/cm2), and 43.75% could cellularize a scaffold at high cell density (~ 100,000 cells/cm2). At passage 2, all samples produced the number of cells required for both recellularization models. Further evaluation revealed that six pediatric samples (11%) and three (50%) adult samples contained basal cells with a squamous basal phenotype. These cells did not form a polarized epithelium or produce differentiated secretory or ciliated cells. In the pediatric population, the squamous basal cell phenotype was associated with degree of prematurity (< 28 weeks, 64% vs. 13%, p = 0.02), significant pulmonary history (83% vs. 34%, p = 0.02), specifically with bronchopulmonary dysplasia (67% vs. 19%, p = 0.01), and patients who underwent previous tracheostomy (67% vs. 23%, p = 0.03). CONCLUSIONS: In summary, screening high-risk pediatric or adult population based on clinical risk factors and laboratory findings could define appropriate candidates for airway reconstruction with tracheal scaffolds. LEVEL OF EVIDENCE: Level III Cohort study.

Expansion of the core features of VACTERL association to include genital anomalies.

Genital anomalies have been reported with VACTERL association but not considered a core feature. Acute and chronic complications stemming from unrecognized genital anomalies have been reported in adolescents and young adults with VACTERL association. We sought to determine the frequency and severity of genital anomalies in VACTERL patients and identify which core features were more frequently associated with genital anomalies. A retrospective chart review from January 2010 to October 2021 identified 211 patients with two or more core VACTERL features, 34% of whom had a genital anomaly. The majority of genital anomalies (83% of those in males and 90% in females) were classified as functionally significant (requiring surgical intervention or causing functional impairment). The frequency of genital anomalies in the VACTERL cohort was higher if anorectal malformations or renal anomalies were present in both males and females and if vertebral anomalies were present in females. Due to their functional significance, genital anomalies should be assessed in all patients with two or more core features of VACTERL association, especially in those with anorectal or renal anomalies. Most genital anomalies in males will be detected on physical examination but additional investigation is often needed to detect genital anomalies in females. The timing and type of investigation are subjects for future study.

Seihaito, a Kampo medicine, attenuates IL-13-induced mucus production and goblet cell metaplasia.

Goblet cell hyperplasia and increased mucus production are features of airway diseases, including asthma, and excess airway mucus often worsens these conditions. Even steroids are not uniformly effective in mucus production in severe asthma, and new therapeutic options are needed. Seihaito is a Japanese traditional medicine that is used clinically as an antitussive and expectorant. In the present study, we examined the effect of Seihaito on goblet cell differentiation and mucus production. In in vitro studies, using air-liquid interface culture of guinea-pig tracheal epithelial cells, Seihaito inhibited IL-13-induced proliferation of goblet cells and MUC5AC, a major component of mucus production. Seihaito suppressed goblet cell-specific gene expression, without changing ciliary cell-specific genes, suggesting that it inhibits goblet cell differentiation. In addition, Seihaito suppressed MUC5AC expression in cells transfected with SPDEF, a transcription factor activated by IL-13. Furthermore, Seihaito attenuated in vivo goblet cell proliferation and MUC5AC mRNA expression in IL-13-treated mouse lungs. Collectively, these findings demonstrated that Seihaito has an inhibitory effect on goblet cell differentiation and mucus production, which is at least partly due to the inhibition of SPDEF.

Radiofrequency ablation for papillary thyroid microcarcinoma with a trachea-adjacent versus trachea-distant location.

OBJECTIVE: To evaluate the outcomes of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) adjacent to the trachea and compare them with those of PTMC distant from the trachea. METHODS: Patients who received RFA for solitary low-risk PTMC between June 2014 and July 2020 were reviewed and classified into adjacent and distant groups. To balance between-group confounders, the propensity score matching approach was employed. Volume, volume reduction ratio (VRR), tumor disappearance, complications, and disease progression were assessed and compared between the groups. Furthermore, factors affecting disease progression were evaluated. RESULTS: A total of 122 and 470 patients were included in the adjacent and distant groups, respectively. Overall VRR was 99.5% ± 3.1 and cumulative tumor disappearance rate was 99.4% after a mean follow-up time of 40.1 months ± 16.2. Overall disease progression and complications incidence were 3.7% and 1.0%, respectively. No substantial differences were observed between the two groups in the latest volume (0.8 mm3 ± 4.1 vs. 0.9 mm3 ± 4.2, p = .77), VRR (99.7% ± 1.6 vs. 99.5% ± 2.7, p = .75), cumulative tumor disappearance rate (92.6% vs. 94.2%, p = .58), and incidence of disease progression (4.1% vs. 4.5%, p = .70) and complication (1.7% vs. 0.8%, p = .86) after 1:2 matching. Additionally, tracheal adjacency exhibited no association with disease progression in multivariate Cox regression analysis (p = .73). CONCLUSION: For eligible patients with PTMC located adjacent to or distant from the trachea, RFA may offer a safe and effective alternative treatment method.

The Wound Healing of Autologous Regenerative Factor on Recurrent Benign Airway Stenosis: A Canine Experimental and Pilot Study.

INTRODUCTION: Benign airway stenosis (BAS) is a severe pathologic condition. Complex stenosis has a high recurrence rate and requires repeated bronchoscopic interventions for achieving optimal control, leading to recurrent BAS (RBAS) due to intraluminal granulation. METHODS: This study explored the potential of autologous regenerative factor (ARF) for treating RBAS using a post-intubation tracheal stenosis canine model. Bronchoscopic follow-ups were conducted, and RNA-seq analysis of airway tissue was performed. A clinical study was also initiated involving 17 patients with recurrent airway stenosis. RESULTS: In the animal model, ARF demonstrated significant effectiveness in preventing further collapse of the injured airway, maintaining airway patency and promoting tissue regeneration. RNA-seq results showed differential gene expression, signifying alterations in cellular components and signaling pathways. The clinical study found that ARF treatment was well-tolerated by patients with no severe adverse events requiring hospitalization. ARF treatment yielded a high response rate, especially for post-intubation tracheal stenosis and idiopathic tracheal stenosis patients. CONCLUSION: The study concludes that ARF presents a promising, effective, and less-invasive method for treating RBAS. ARF has shown potential in prolonging the intermittent period and reducing treatment failure in patients with recurrent tracheal stenosis by facilitating tracheal mucosal wound repair and ameliorating tracheal fibrosis. This novel approach could significantly impact future clinical applications.

Application of modified spiral tracheoplasty in thyroid carcinoma with trachea invasion: a retrospective analysis of 15 cases.

BACKGROUND: To describe the indications, techniques and preliminary experience of modified spiral tracheoplasty in the reconstruction of large tracheal defect after thyroidectomy. METHODS: The medical records of patients who underwent tracheal torsion to repair large tracheal defects after thyroid carcinoma surgery from January 2019 to January 2022 were retrospectively reviewed. The extent of tracheal defect, duration of tracheal reconstruction, postoperative complications and surgery results were analyzed. RESULTS: The duration of tracheal reconstruction was 30-60 min. No postoperative bleeding, incision infection, tracheostomy stenosis occurred. Recurrent laryngeal nerve palsy occurred in 5 patients. All patients were followed up for 24 to 60 months. The 2-year overall survival rate was 100%, the 2-year local control rate of trachea was 100%, and the 2-year tumor-free survival rate was 81.8%. CONCLUSION: The modified spiral tracheoplasty is a safe and effective method to repair the large defect of trachea after thyroid carcinoma invading the trachea.

Radiographic and computed tomographic characteristics of intraluminal tracheal adenoma in a cat.

A 13-year-old spayed female Persian cat presented with dyspnea and nasal discharge. Thoracic radiography revealed a dome-shaped soft-tissue opacity in the carina. Computed tomography confirmed a soft tissue-attenuating mass in the carina and the left and right proximal main bronchi that appeared to arise from the tracheal wall. Tracheoscopy revealed an intraluminal broad-based mass with multilobulated borders at the same location. Histopathological evaluation revealed a benign neoplastic process of the glandular epithelial lineage, which was considered an adenoma. Tracheal adenomas should be included in the differential diagnosis of tracheal masses.

[Tracheal Tumours]. / Trachealtumoren.

Malignant primary tracheal tumours are rare. The most common histological subtypes are squamous cell carcinoma and adenoid cystic carcinoma. These two entities have different prognoses and growth patterns. Tracheobronchoscopy and thoracic sectional imaging are standard diagnostic tools for tumour staging and local evaluation. Complete surgical resection of the affected tracheal segment is the treatment of choice for limited disease without distant metastases. Incomplete gross tumour resection with additional irradiation is an acceptable therapeutic option for adenoid cystic carcinoma. Interventional endoscopy with tumour debulking or tracheal stenting and/or definitive mediastinal radiotherapy are treatment alternatives in either a locally advanced or palliative setting.

RT-qPCR investigation of post-mortem tissues during COVID-19.

In 2020, there were numerous cases in Kazakhstan with clinical symptoms of COVID-19 but negative PCR results in nasopharyngeal and oropharyngeal swabs. The diagnosis was confirmed clinically and by CT scans (computed tomography). The problem with such negative PCR results for SARS-CoV-2 infection confirmation still exists and indicates the need to confirm the diagnosis in the bronchoalveolar lavage in such cases. There is also a lack of information about confirmation of SARS-CoV-2 infection in deceased patients. In this study, various tissue materials, including lungs, bronchi, and trachea, were examined from eight patients who died, presumably from SARS-CoV-2 infection, between 2020 and 2022. Naso/oropharyngeal swabs taken from these patients in hospitals tested PCR negative for SARS-CoV-2. This study presents a modified RNA isolation method based on a comparison of the most used methods for RNA isolation in laboratories: QIAamp Viral RNA Mini Kit and TRIzol-based method. This modified nucleic acid extraction protocol can be used to confirm SARS-CoV-2 infection by RT-qPCR in the tissues of deceased patients in disputed cases. RT-qPCR with RNA of SARS-CoV-2 re-extracted with such method from post-mortem tissues that were stored at -80 °C for more than 32 months still demonstrated high-yielding positive results.

[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.

E3 ubiquitin ligase FBXW7 balances airway cell fates.

The airway epithelium is composed of multiple cell types each with designated roles. A stereotyped ratio of these cells is essential for proper airway function. Imbalance of airway cell types underlies many lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma. While a number of signals and transcription factors have been implicated in airway cell specification, how cell numbers are coordinated, especially at the protein level is poorly understood. Here we show that in the mouse trachea which contain epithelial cell types similar to human airway, epithelium-specific inactivation of Fbxw7, which encodes an E3 ubiquitin ligase, led to reduced club and ciliated cells, increased goblet cells, and ectopic P63-negative, Keratin5-positive transitory basal cells in the luminal layer. The protein levels of FBXW7 targets including NOTCH1, KLF5 and TGIF were increased. Inactivation of either Notch1, Klf5 but not Tgif genes in the mutant background led to attenuation of selected aspects of the phenotypes, suggesting that FBXW7 acts through different targets to control different cell fates. These findings demonstrate that protein-level regulation by the ubiquitin proteasome system is critical for balancing airway cell fates.

Benign but fatal: management of endotracheal Rosai-Dorfman disease with acute onset.

Rosai-Dorfman disease (RDD) is a non-malignant condition mainly manifesting as a proliferation of histiocytes in lymph nodes. Endotracheal RDD (ERDD) with an acute onset presentation is extremely rare. There are few case reports of ERDD mainly concerning its pathology, diagnostics and bronchoscopic treatment, without providing sufficient clinical information from a comprehensive perspective. As a novel and challenging technique, tracheal resection and reconstruction (TRR) with spontaneous-ventilation video-assisted thoracoscopic surgery (SV-VATS) has been reported as feasible and safe in highly selected patients, but few centres have shared their experience with this approach. This case-based discussion includes not only practical issues in the management of a life-threatening ERDD patient, but also specialists' views on the management of acute obstructive airway, and the surgeons' reflection on TRR with SV-VATS.

Vimentin affects inflammation and neutrophil recruitment in airway epithelium during Streptococcus suis serotype 2 infection.

Streptococcus suis serotype 2 (SS2) frequently colonizes the swine upper respiratory tract and can cause Streptococcal disease in swine with clinical manifestations of pneumonia, meningitis, and septicemia. Previously, we have shown that vimentin, a kind of intermediate filament protein, is involved in the penetration of SS2 through the tracheal epithelial barrier. The initiation of invasive disease is closely related to SS2-induced excessive local inflammation; however, the role of vimentin in airway epithelial inflammation remains unclear. Here, we show that vimentin deficient mice exhibit attenuated lung injury, diminished production of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and the IL-8 homolog, keratinocyte-derived chemokine (KC), and substantially reduced neutrophils in the lungs following intranasal infection with SS2. We also found that swine tracheal epithelial cells (STEC) without vimentin show decreased transcription of IL-6, TNF-α, and IL-8. SS2 infection caused reassembly of vimentin in STEC, and pharmacological disruption of vimentin filaments prevented the transcription of those proinflammatory cytokines. Furthermore, deficiency of vimentin failed to increase the transcription of nucleotide oligomerization domain protein 2 (NOD2), which is known to interact with vimentin, and the phosphorylation of NF-κB protein p65. This study provides insights into how vimentin promotes excessive airway inflammation, thereby exacerbating airway injury and SS2-induced systemic infection.

The Novel Application of Robotic-Assisted Bronchoscopy Combined with Photodynamic Therapy for Adenoid Cystic Carcinoma of the Trachea.

Robotic platforms have been widely used in the various fields of clinical diagnosis and therapy of diseases in the past decade. Robotic-assisted bronchoscopy (RAB) demonstrates its advantages of visibility, flexibility, and stability in comparison to conventional bronchoscopic techniques. Improving diagnostic yield and navigation yield for peripheral pulmonary lesions has been defined; however, RAB platform of treatment was not reported. In this article, we report a case of a 52-year-old woman who was diagnosed with the tracheal adenoid cystic carcinoma and recurred in the second postoperative year, leading to the involvement of the entire tracheal wall and lumen obstruction. Since the lesion was inoperable, we combined RAB and photodynamic therapy (PDT) for the patient. The potential advantages of using RAB for PDT delivery include precise light irradiation of target lesions and stable intra-operative control over the long term. This is a novel application of RAB combined with PDT for airway diseases. The case report may provide a new insight into the diagnosis and treatment of pulmonary diseases. In addition to improving the diagnostic rates, the RAB platform may also play an important role in the treatment of airway and lung disease in the future.

The effect of suture techniques on the outcome of tracheal reconstruction: An observational study and review of literature.

BACKGROUND: Tracheal resection and anastomosis surgery is a safe operation and is used to treat various benign and malignant diseases of the trachea. However, tracheal stenosis is among the main anastomotic complications following this procedure. Surgeons use both the continuous and the interrupted suture techniques for tracheal anastomosis, but contradicting results in each technique's complications have been reported in various studies. In this study, we aimed to compare the outcome of these two different suture techniques and a relevant literature review. METHODS: Surgical records during a period of 15 years (2005-2019) were screened for tracheal reconstruction surgery in affiliated hospitals of Shiraz University of Medical Sciences, Shiraz, Iran. A total of 82 patients were evaluated based on surgical and suture features, along with their follow-up bronchoscopy for anastomotic complications. RESULTS: Post-operational subclinical restenosis occurred in 8 (15.3%) out of 52 and 10 (33.3%) of 30 patients who underwent continuous and interrupted suturing techniques, respectively. Also, 6 (20%) patients in the interrupted group developed symptomatic restenosis, while in the continuous group, only one patient was clinically symptomatic. The patients with continuous suture technique had a shorter surgery time than patients whose interrupted technique was used (P < 0.001). CONCLUSIONS: Based on our results, we conclude that restenosis is significantly reduced when the continuous technique is applied for tracheal anastomosis; However, the results are contradicting in relevant literature and due to the retrospective nature of our study, further human studies and clinical trials are warranted.

[Standardized and individualized treatment improves survival rate and quality of life for advanced thyroid cancer].

The overall prognosis of differentiated thyroid carcinoma is favorable, but some patients still progress to a locally advanced stage. At present, there are still some problems in the diagnosis and treatment of locally advanced thyroid cancer, which have not been completely clarified, and have caused some problems to the clinical treatment. This article provides a comprehensive analysis and elaboration on the selection of surgical methods for local advanced thyroid cancer, management of recurrent laryngeal nerve and trachea, timing selection of staging surgery, and targeted therapy, aiming at promoting standardized and individualized treatment for advanced thyroid cancer and improving the survival rate and quality of life.

[A Case of Esophageal Carcinoma with Tracheal Invasion after Preoperative Treatment with Docetaxel, Cisplatin, and 5-Fluorouracil in Which Definitive Chemoradiotherapy and Salvage Esophagectomy Prolonged Survival].

A 57-year-old man was diagnosed as having resectable advanced esophageal carcinoma adjacent to the trachea(Ut, cT3N0M0)and received preoperative docetaxel, cisplatin, and 5-fluorouracil therapy. Due to tracheal tumor invasion and upstaging to cT4bN0M0 after 1 course of chemotherapy, the treatment was converted to definitive chemoradiotherapy (CRT). A remarkable response with no evidence of tracheal invasion was observed on computed tomography following definitive CRT. He underwent successful curative resection with salvage esophagectomy, and the resected tumor was staged as pT1bN0M0. No adjuvant therapy was administered, and the patient was alive with no evidence of disease at the 5-year postoperative follow-up. The response to preoperative treatment should be meticulously assessed and appropriate treatment modalities used to avoid overlooking the potential for cure, even if the response to preoperative treatment with docetaxel, cisplatin, and 5-fluorouracil is poor.

TRACHEOBRONCHIAL MORPHOMETRY CORRELATES WITH DEMOGRAPHIC CHARACTERISTICS AND INFECTIONS IN CRITICALLY ILL PATIENTS.

Tracheal measurements in the intensive care unit (ICU) are important for the choice of endotracheal tube and may correlate with patient demographic characteristics and infections. The study included 42 surgical patients, age 60 [48-71] years, who underwent diagnostic chest computed tomography (CT) scans during treatment in the ICU, Osijek University Hospital, in 2019 and 2020. CT scans were analyzed using AW Server 3.2. Measurement analysis showed that the diameters of the tracheobronchial tree, the length of the trachea and left main bronchus were significantly larger in men compared to women (p<0.05 all). The smallest tracheal upper diameter was 15.25 [IQR 11.8-18.8] mm vs. 17.95 [13.55-20.05] mm in septic and nonseptic patients, respectively (p=0.028). A total of 26 patients who underwent CT scans developed nosocomial pneumonia. It was right-sided in 15, left-sided in 6 and bilateral in 5 patients, and correlated significantly with the left main bronchus length (ρ=0.515, p=0.007). No correlation was observed between tracheobronchial measurements and length of ICU treatment, number of hours spent on mechanical ventilation, or survival. A larger study could provide better data on the importance of tracheobronchial tree measurements in ICU patients.