Murine model of eosinophilic chronic rhinosinusitis with nasal polyposis inducing neuroinflammation and olfactory dysfunction.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory condition affecting the nasal and paranasal sinus mucosa, often accompanied by olfactory dysfunction. Eosinophilic CRS with nasal polyps (ECRSwNP) is a subtype of CRS characterized by eosinophilic infiltration. Animal models for ECRSwNP with olfactory dysfunction are necessary for exploring potential therapeutic strategies. OBJECTIVE: The aim of this study was to establish a mouse model of ECRSwNP combined with olfactory dysfunction in a shorter time frame using intranasal ovalbumin and Aspergillus protease (AP) administration. The efficacy of the model was validated by evaluating sinonasal inflammation, cytokine levels, olfactory function, and neuroinflammation in the olfactory bulb. METHODS: Male BALB/c mice were intranasally administered ovalbumin and AP for 6 and 12 weeks to induce ECRSwNP. The resultant ECRSwNP mouse model underwent histologic assessment, cytokine analysis of nasal lavage fluid, olfactory behavioral tests, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. RESULTS: The developed mouse model exhibited substantial eosinophil infiltration, increased levels of inflammatory cytokines in nasal lavage fluid, and confirmed olfactory dysfunction through behavioral assays. Furthermore, olfactory bulb inflammation and reduced mature olfactory sensory neurons were observed in the model. CONCLUSION: This study successfully established a validated mouse model of ECRSwNP with olfactory dysfunction within a remarkably short span of 6 weeks, providing a valuable tool for investigating the pathogenesis and potential therapies for this condition. The model offers an efficient approach for future research in CRS with nasal polyps and olfactory dysfunction.

Perineural invasion is a poor prognostic factor for sinonasal squamous cell carcinoma.

OBJECTIVES: In this study, our primary objective is to elucidate the correlation between sinonasal squamous cell carcinoma (SCC) and perineural invasion (PNI), a topic that has received limited attention in prior literature. Furthermore, we have undertaken an examination of various other clinicopathological factors. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients aged ≥ 20 years with newly diagnosed sinonasal cancer and received treatment and care at a tertiary medical center. We excluded patients who did not have an SCC diagnosis, those who underwent palliative surgery, and individuals with insufficient follow-up data at the study endpoint. Ultimately, a total of 49 eligible participants were included in our further analysis. RESULTS: PNI and advanced T staging were associated with increased risk of local recurrence (LR). Furthermore, PNI was significantly associated with an adverse prognosis in terms of LR-free survival. Participants with PNI had significantly worse overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS). Patients with LR had significantly worse OS, DFS, and DSS. CONCLUSION: PNI is associated with an elevated risk of LR and reduced OS, DFS, and DSS in patients with sinonasal SCC. These findings can facilitate the formulation of more targeted and effective treatment strategies for sinonasal SCC in clinical practice.

Lipopolysaccharide-Initiated Rhinosinusitis Causes Neuroinflammation and Olfactory Dysfunction in Mice.

BACKGROUND: Olfactory dysfunction is a common disease and it may be caused by sinonasal inflammation, toxin inhalation, or neurological disorders. After sinonasal inflammation, if both olfactory neuroinflammation and olfactory dysfunction occur still under investigation. OBJECTIVE: This study aimed to investigate whether neuroinflammation and olfactory dysfunction occur after lipopolysaccharide (LPS)-initiated rhinosinusitis. METHODS: Adult C57BL/6 mice were intranasally administered with LPS for 3 weeks. The olfactory function was evaluated with a buried food test. The inflammatory status of sinonasal cavity and olfactory bulb was evaluated with histology and biochemistry. RESULTS: After 3-week LPS treatment, mice developed olfactory dysfunction, sinonasal cavity, and olfactory bulb inflammation. LPS-treated mice had greater sinonasal mucosal thickness. Besides, pro-inflammatory interleukin-6, the number of goblet cells and neutrophils in the sinonasal cavity was increased after LPS administration. The olfactory sensory neurons in the olfactory epithelium and the olfactory bulb were decreased, and the olfactory function was impaired by LPS administration. Inflammatory cytokines such as interferon-γ and tumor necrosis factor-α were increased in the olfactory bulb. CONCLUSION: This study showed that LPS-initiated rhinosinusitis caused olfactory neuroinflammation and olfactory dysfunction in mice.

Analysing sinonasal microbiota of fungal rhinosinusitis by next-generation sequencing.

OBJECTIVES: Fungal rhinosinusitis is an inflammatory disease of the nose that may lead to life-threatening complications. This study compared the bacterial and fungal microbiomes between patients with invasive fungal rhinosinusitis (IFRS) and non-IFRS (NIFRS). DESIGN: This was a prospective study including 18 IFRS and NIFRS patients. Fungal and bacterial microbiomes from surgical specimens were sequenced from amplicons of the internal transcribed spacer 1 (ITS1) region and the V3-V4 region of the 16S locus, respectively. Microbiomes were generated using the Illumina MiSeq System 2 x 301 base pair chemistry with a paired-end protocol. SETTING: Tertiary medical centre. RESULTS: Targeted metagenomics identified Aspergillus spp. as the predominant fungus in both IFRS and NIFRS patients. Based on phylum and genera level diversity, and abundance differences, significant differences of operational taxonomic units (OTUs) (Fusobacterium, Prevotella, Pseudomonas, Neisseria and Streptococcus) were more abundant in NIFRS compared with IFRS patients. CONCLUSIONS: This is the first study to analyse bacterial and fungal microbiomes in patients with IFRS and NIFRS via ITS1 and 16S genomics sequencing. Bacterial microbiomes from patients with IFRS demonstrated dysbiosis (alterations in diversity and abundance) compared to those from patients with NIFRS.

Antipsychotic drug trifluoperazine as a potential therapeutic agent against nasopharyngeal carcinoma.

BACKGROUND: Trifluoperazine (TFP) is a typical antipsychotic primarily used to treat schizophrenia. In this study, we aimed to evaluate whether TFP can be used as a therapeutic agent against nasopharyngeal carcinoma (NPC) and identify its underlying molecular mechanisms. METHODS: We used NPC-TW01, TW03, TW04, and BM to assess the anticancer effects of TFP by using cytotoxicity, wound healing, colony formation, and cell invasion assays. An in vivo animal study was conducted. RNA sequencing combined with Ingenuity Pathways Analysis was performed to identify the mechanism by which TFP influences NPC cells. RESULTS: Our data revealed that TFP decreased NPC cell viability in a dose-dependent manner. The invasion and migration of NPC tumor cells were inhibited by TFP. An in vivo study also demonstrated the anticancer effects of TFP. RNA sequencing revealed several anticancer molecular mechanisms following TFP administration. CONCLUSIONS: The antipsychotic drug TFP could be a potential therapeutic regimen for NPC treatment.

Catechol-functionalized sulfobetaine polymer for uniform zwitterionization via pH transition approach.

The study aims to develop a modification strategy to facilitate uniform catechol-assisted zwitterionization on nitinol alloy for bio-compatibility and fouling resistance. Catechol-functionalized polysulfobetaine methacrylate (pSBMA/DA) is synthesized via dopamine-initiated photo-polymerization. Under UV irradiation, semiquinone radicals from dopamine (DA) can be generated, and prevented loss of one electron to intramolecular cyclization and intermolecular dimerization in a solution at pH 2. Pseudo-first-order polymerization kinetics, and relations of apparent rate constant and number average molecular weight with the molar ratio of DA in photopolymerization for pSBMA/DA are unveiled. In a solution at pH 3, PSBMA/DA begins aggregation, kept catechol moieties from premature oxidization, and enabled even deposition on the nitinol substrate. After pH regulation to 8.5, pSBMA/DA extends, and concurrently catechol moieties are activated to interact with the nitinol surface via the formation of bidentate binding. X-ray photoelectron spectroscopy (XPS) analysis revealed that a shorter pSBMA/DA chain with higher catechol content provides more anchoring sites to enhance zwitterionic moieties coverage on substrates. Interestingly, atomic force microscopy (AFM) images revealed a smooth and uniform deposition of pSBMA/DA using the pH-transition method. Strong ionic hydration of pSBMA/DA coating on nitinol surface repels non-specific adsorption of bio-foulants, permitting excellent antifouling properties. Zwitterion-modified nitinol achieved a reduction rate of 99.9% against Escherichia coli and Staphylococcus aureus attachment. In addition, pSBMA/DA exhibits a robust antifouling performance to NIH 3T3 mouse fibroblasts in culture media after incubation for 24 h. Overall, the pSBMA/DA coating via pH transition approach opens up a promising strategy to facilitate uniform surface functionalization for antifouling and coating technology.

Prior cancer history predicts the worse survival of patients with nasopharyngeal carcinoma.

PURPOSE: Previous cancers can be observed in patients with nasopharyngeal carcinoma (NPC). However, whether prior cancer diagnosis affects survival outcomes remains unknown. This study aimed to explore the impact of prior cancer on the survival of patients with NPC. METHODS: We retrospectively collected data from 666 NPC patients between 2006 and 2018. The patients in this study were divided into those without prior cancer, with prior head and neck cancer, and prior non-head and neck cancer. The demographic data and survival of these groups were then analyzed. The independent prognostic factors for NPC were determined using multivariate Cox regression analysis. RESULTS: We identified 25 NPC patients with prior cancer in our case series, most of whom had a history of colorectal cancer. Patients with a history of cancer were older than those without a history of cancer (p = 0.001). In the subgroup analysis stratified by the timing of prior cancer, NPC patients with prior non-head and neck cancer within 24, 36, 60, and 120 months showed worse survival than patients without prior cancer (all p < 0.05). When stratified by cancer stage, stage III NPC patients with prior non-head and neck cancer showed worse survival than patients without prior cancer (p < 0.001). Prior cancer and diabetes can predict worse survival in patients with stage III NPC. CONCLUSION: This study demonstrated that prior cancer and diabetes are independent prognostic factors in patients with stage III NPC.

Predicting the Need for Desmopressin Treatment During Inpatient and After Discharge Following Endoscopic Sellar Surgery.

INTRODUCTION: Postoperative diabetes insipidus (DI) is a common complication following endoscopic sellar surgery. However, the requirement of desmopressin treatment for patients with DI are heterogenous. Although the predictors of postoperative DI have been reported, whether these patients required desmopressin treatment remained uninvestigated. Predicting the need of desmopressin can benefit clinical decision making more directly than predicting the occurence of postoperative DI. This study aimed to identify variables that predict the need for desmopressin treatment following sellar surgery. METHODS: Patients undergoing endoscopic sellar surgery between 2016 and 2019 were retrospectively reviewed. Twenty-three variables, characterized as potential predictors for requiring desmopressin treatment, were analyzed. To assess the capability to generalize the identified predictors, external validation with receiver operating characteristic (ROC) analysis was performed using a second series from 2019 to 2020. RESULTS: Postoperative DI occurred in 40 of 159 included patients. Twelve patients required inpatient desmopressin treatment and 20 patients needed desmopressin prescription after discharge. The potential predictors of requiring any desmopressin use included higher peak sodium (Na) level (p = 0.007), lower minimum Na level (p = 0.043), and higher peak urine output (p = 0.006), but these were not supported by external validation. The predictors of requiring desmopressin after discharge included higher peak Na (p = 0.040) and minimum Na levels (p = 0.048), which were supported by external ROC validation showing areas under curve of 0.787, 0.611, and 0.898 for peak Na (p = 0.036), minimum Na (p = 0.460), and peak Na - minimum Na levels (p < 0.001), respectively. A criterion of peak Na ≥ 150 mmol/L or peak Na - minimum Na ≥ 10 predicted the need of desmopressin prescription after discharge. A postoperative management algorithm was proposed. CONCLUSION: The required treatments for patients with postoperative DI following endoscopic sellar surgery are heterogenous. Elevated peak Na and large peak Na-minimum Na levels in the perioperative period predicted requiring desmopressin after hospital discharge. Patients with peak Na <150 mmol/L and peak Na-minimum Na <10 can be safely discharged without desmopressin prescription.

Vertebral artery stenosis predicts cerebrovascular diseases following radiotherapy for nasopharyngeal carcinoma.

PURPOSE: Radiotherapy for nasopharyngeal carcinoma (NPC) may induce cerebrovascular diseases including ischemic stroke and transient ischemic attack (TIA), which can cause severe disability. However, information on the incidence and predictors of cerebrovascular diseases is scarce. This study aimed to estimate the incidence of cerebrovascular diseases following NPC, and attempts to ascertain the predictors of cerebrovascular diseases to facilitate early prevention. METHODS: We performed a retrospective cohort study on 655 NPC patients who received radiotherapy between 2006 and 2018 in a medical center. This study analyzed the incidence, clinical and imaging presentation of patients with cerebrovascular diseases. Cox proportional hazard model was used to identify risk factors associated with cerebrovascular diseases following radiotherapy. RESULTS: There were 14 patients who developed an ischemic stroke, and 3 patients developed a TIA after a mean follow-up of 5.8 years. Most ischemic events were from large-artery atherosclerosis (76.5%), and the most common symptom of ischemic stroke was unilateral limb weakness (57.1%). The cumulative incidence of ischemic stroke or TIA 15 years after radiotherapy was 9.1% (95% confidence interval [CI] = 4.7-17.2%). Multivariate Cox regression identified vertebral artery stenosis (HR: 18.341; 95% CI = 3.907-86.100; P < 0.001), atrial fibrillation (HR: 13.314; 95% CI = 1.306-135.764; P = 0.029), and hypertension (HR: 7.511; 95% CI = 1.472-38.320; P = 0.015) as independent predictors of ischemic stroke or TIA. CONCLUSION: Our study found that NPC patients with vertebral artery stenosis, atrial fibrillation, or hypertension carry a higher risk for ischemic stroke or TIA. Regular assessment of vertebral artery after radiotherapy was suggested.

The role of nasopharyngectomy in the management of nasopharyngeal carcinoma.

PURPOSE OF REVIEW: Recently, endoscopic nasopharyngectomy (ENPG) has become an effective treatment for locally recurrent nasopharyngeal carcinoma (NPC). This article reviews recent publications on ENPG and specifically addresses the surgical anatomy of the nasopharynx and discusses several important issues regarding ENPG. RECENT FINDINGS: The surgical techniques for ENPG have been previously described in several studies. The latest published data revealed good outcomes of ENPG compared with intensity-modulated radiation therapy (IMRT) in recurrent NPC. In addition, ENPG avoids severe reirradiation side effects. This review highlights the surgical anatomy of ENPG, which is important in preventing possible serious complications. SUMMARY: ENPG is a good option for managing recurrent NPC. Careful preoperative evaluation and a full understanding of the surgical anatomy help in preventing damage to nearby critical neurovascular structure. Long-term follow-up is still needed to evaluate its eventual morbidity and efficacy.

Combining sinus plain film and sinus ultrasound as a screening tool for maxillary fungal sinusitis.

BACKGROUND: Early identification of fungal sinusitis remains a challenge. Previously, we observed a high false negative rate of using A-mode ultrasound to diagnose maxillary fungal sinusitis. This study aims to assess the accuracy of the diagnosis of fungal maxillary sinusitis using sinus plain film and ultrasound. METHODS: The screening criteria is defined as the combination of a positive sinus plain film and a false negative sinus ultrasound. We retrospectively reviewed preoperative imaging of patients with fungal sinusitis and unilateral bacterial sinusitis of the maxillary sinus undergoing functional endoscopic sinus surgery from May 2013 to December 2019 in our hospital and evaluated the diagnostic performance of this screening method. RESULTS: Forty-eight patients were included. Twenty-two and 26 patients were diagnosed with fungal sinusitis and bacterial sinusitis, respectively. Sixteen patients (72.7%) with fungal sinusitis presented with a false negative sinus ultrasound and met our screening criteria for fungal sinusitis. The screening criteria reached significance in the receiver operating characteristic curve analysis (p < 0.001). The area under the curve was 0.829. The sensitivity, specificity, and accuracy are 72.7%, 93.2%, and 88.4%, respectively. CONCLUSION: A high false negative rate of sinus ultrasound in patients with fungal sinusitis was found. A positive sinus plain film combined with a false negative sinus ultrasound can potentially become an easy and cost-effective screening tool for diagnosing fungal maxillary sinusitis before consideration of computed tomography scanning.

Invasive Fungal Rhinosinusitis with and without Orbital Complications: Clinical and Laboratory Differences.

BACKGROUND: Invasive fungal rhinosinusitis (IFS) is a rare but often fatal disease. There are limited studies regarding IFS with orbital complications (IFSwOC). The present study aimed to identify the clinical signs associated with IFSwOC and prognosticators of the disease. METHODS: A retrospective case series was conducted of patients histopathologically confirmed IFS or fungal rhinosinusitis with clinically apparent neuro-orbital complications who underwent surgery between 2008 and 2018. Demographic data, presenting symptoms and signs, culture data, laboratory results, and patient outcomes were obtained from medical records. RESULTS: A total of 38 patients were identified, including 9 patients with IFSwOC, and 29 patients with IFS without orbital complications (IFSsOC). The clinical signs associated with developing orbital complications include headache, fever, sphenoid sinus, or posterior ethmoid sinus involvement, CRP level ≥ 1.025 mg/dL, or ESR level ≥ 46.5 mm/h. In IFSwOC group, male, posterior ethmoid sinus involvement, WBC count ≥ 9000 µL, CRP level ≥ 6.91 mg/dL, or ESR level ≥ 69 mm/h were correlated with a significantly poorer prognosis. CONCLUSION: IFS patients with sphenoid or posterior ethmoid sinus involvement, headache or fever as presenting symptoms, elevated CRP, and ESR level were at risk of developing orbital complications. Timely surgical debridement followed by systemic antifungal treatment may improve treatment outcomes.

DEK-AFF2 fusion-associated papillary squamous cell carcinoma of the sinonasal tract: clinicopathologic characterization of seven cases with deceptively bland morphology.

A novel DEK-AFF2 fusion has been recently identified in four cases of basaloid to nonkeratinizing squamous cell carcinoma (SCC) in the sinonasal tract and middle ear with high-grade morphology. The exceptional response to immune checkpoint inhibitor in the first reported case highlights the potential clinical importance of identifying tumors with DEK-AFF2 fusions. We herein reported the first series of seven cases of DEK-AFF2 fusion-associated sinonasal SCC with deceptively bland morphology, including four cases of low-grade papillary Schneiderian carcinoma, which is a recently described tumor type with unknown molecular underpinnings. The DEK gene rearrangement was confirmed by DEK break-apart fluorescence in situ hybridization and DEK-AFF2 fusion transcripts were detected by reverse transcription polymerase chain reaction. In contrast to the previously reported DEK-AFF2 fusion-positive high-grade carcinomas, these tumors had a monotonous and bland morphology and were all initially diagnosed as sinonasal papilloma (SP) of various types, with or without dysplasia or carcinoma in situ. The tumor was characterized by mixed exophytic and inverted patterns, broad papillary fronds, acantholytic change, cellular monotony, dense neutrophilic infiltrates, and peripheral palisading. All tumors were diffusely positive for p40 or p63 and negative for NUT and p16. Molecular drivers associated with SP, including EGFR and KRAS mutations and both high and low-risk human papillomavirus infection, were negative in all cases. Although there was no overt stromal invasion or desmoplastic reaction in the initial specimens, these tumors tended to progress locoregionally through a prolonged clinical course and occasionally develop lymph node metastases, high-grade transformation, or extensively local destruction eventually leading to death. These justify more aggressive clinical management. Therefore, we propose the new terminology "DEK-AFF2 fusion-associated papillary SCC of the sinonasal tract" to better describe this clinicopathologically and molecularly distinct entity.

Combined Endoscopic Endonasal and Contralateral Transmaxillary Approach for Petrous Cholesteatoma: 2-Dimensional Operative Video.

This 59-yr-old man presented with headache, dizziness, diplopia, and right-side hearing impairment for years. The objective degree of hearing impairment was not available. Magnetic resonance imaging (MRI) showed a right petrous apex lesion centered behind the right petrous internal carotid artery and extending lateral to the medial aspect of the right internal auditory canal. A combined endoscopic endonasal and left contralateral transmaxillary (CTM) approach was performed, and gross-total resection was achieved. Peeling the cyst wall from the dura resulted in minor weeping. It was covered with a left-sided, vascularized nasoseptal flap. His dizziness and diplopia improved immediately after the surgery. Histopathology revealed an epidermoid cyst. In this surgical video, we demonstrate the key steps of the CTM approach for access to the petrous apex posterior to the petrous internal carotid artery (ICA). The patient gave informed consent for surgery and video recording.

Nasal Obstruction as a Potential Factor Contributing to Hypoxemia in Obstructive Sleep Apnea.

PURPOSE: This study aimed to evaluate the correlation between nasal resistance and oxygen desaturation to better elucidate the role of nasal obstruction in the pathophysiology of obstructive sleep apnea (OSA). PATIENTS AND METHODS: Eighty-eight OSA patients aged between 22 and 77 years were enrolled in this study. Nasal resistance was measured at pressures of 75, 150, and 300 Pa, with the patients first in the seated position than in the supine position. Relationships between the oximetric variables and nasal resistance in the seated and supine positions were analyzed. RESULTS: From seated to supine position, a statistically significant increase in nasal resistance was observed at pressures of 75 and 150 Pa (p=0.001 and p=0.006, respectively). Significant positive correlations were noted between nasal resistance in the supine position at 75 Pa (SupineNR75) and oximetry variables, including oxygen desaturation index (ODI, p=0.015) and the percentage of total time with oxygen saturation level lower than 90% (T < 90%, p=0.012). However, significant positive correlations existed only in moderate to severe OSA when the study group was further divided into two subgroups (mild vs moderate to severe OSA). Body mass index (ß = 0.476, p<0.001) and SupineNR75 (ß = 0.303, p=0.004) were identified as independent predictors for increased ODI. CONCLUSION: Nasal resistance in the supine position measured at 75 Pa significantly correlated with the severity of oxygen desaturation. Therefore, nasal obstruction may play an important role in the pathophysiology of hypoxemia in OSA patients, especially in patients with moderate to severe OSA.

Bilateral Smell Preservation is Routinely Possible following Endoscopic Endonasal Approach for Sellar/Suprasellar Lesions.

Objective The endoscopic endonasal approach (EEA) has been shown to be an effective means to access sellar lesions. However, there are limited studies centered on evaluating olfactory function after surgery. In this study, we assessed the pre- and postoperative olfactory function of patients who underwent EEA for sellar and suprasellar lesions. The impact of nasoseptal flap use on olfaction was further analyzed. Study Design A retrospective study. Setting A tertiary-care referral center in Taiwan. Participants Patients with sellar and suprasellar lesions who underwent EEA and pre- and postoperative olfaction assessment from August 2015 to March 2018 were included in the study. Main Outcome Measures The patients' olfactory function was examined pre-and postoperatively using the Sniffin' Sticks odor identification test. Data regarding demographics, olfactory scores, pathology, reconstructive technique, graft usage, and extent of resection were retrieved. Results A total of 106 patients (36 males and 70 females) were enrolled, with a mean age of 51 years. There were 76 pituitary tumors, 12 Rathke's cleft cysts, 7 craniopharyngiomas, 7 meningiomas, and 4 other lesions. The nasoseptal flap was used in 39 patients for skull base reconstruction, and these patients had no statistically significant change between pre- and postoperative olfactory scores ( p = 0.283). Moreover, a statistically significant improvement of olfactory scores was found in patients in whom the nasoseptal flap was not used. Conclusion Olfactory function may be reliably preserved after EEA, with or without nasoseptal flap harvest and use.

Association Between Breathing Route, Oxygen Desaturation, and Upper Airway Morphology.

OBJECTIVES/HYPOTHESIS: This study aimed to assess the role of capnography in objectively evaluating breathing routes during drug-induced sleep endoscopy (DISE) and further elucidate the relationship between breathing route, obstructive sleep apnea (OSA) severity, and DISE findings. STUDY DESIGN: Prospective observational study. METHODS: Nighty-five patients with established OSA were recruited for this study from May 2017 to May 2019. DISE was performed in the operating room. Sedation was maintained with propofol using a target-controlled infusion system and the depth of sedation was monitored based on the bispectral index. The breathing routes, which included oral breathing, oronasal breathing, and nasal breathing, were detected using capnography. DISE findings were recorded using the VOTE (velum, oropharynx, base of tongue, and epiglottis) classification. RESULTS: Patients with mouth breathing were associated with increased OSA severity, worse oximetric variables, and higher body mass index in comparison with those with other breathing routes. Mouth breathing was associated with a higher degree and higher prevalence of lateral pharyngeal wall collapse and tongue base collapse during DISE. CONCLUSIONS: Mouth breathing was significantly associated with worse oxygen desaturation and increased degree of upper airway collapse. Therefore, patients with mouth breathing during propofol-based intravenous anesthesia should be carefully monitored. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E659-E664, 2021.

Dynamic tongue base thickness measured by drug-induced sleep ultrasonography in patients with obstructive sleep apnea.

BACKGROUND/PURPOSE: The aim of this study was to determine the value of drug-induced sleep ultrasonography (DISU) for evaluating tongue base thickness (TBT) from the awake state to drug-induced sleep, to further understand the impact of dynamic changes in TBT in obstructive sleep apnoea (OSA) patients. METHODS: From May 2017 to May 2018, thirty patients with OSA were prospectively recruited. Sleep was induced with propofol via use of a target-controlled infusion (TCI) system. The depth of sedation was monitored by the bispectral (BIS) index with BIS levels ranging from 50 to 70. The dynamic change in the tongue base from the awake state to drug-induced sleep was recorded. The correlation between TBT in the awake state and in drug-induced sleep with OSA severity was analysed. RESULTS: The mean TBT in drug-induced sleep was significantly greater than that in the awake state (66.2 ± 4.8 mm vs 61.6 ± 4.6 mm, P < 0.001). TBT in drug-induced sleep was more correlated with AHI compared to TBT in the awake state (r = 0.50 vs r = 0.40). This study showed that TBT in drug-induced sleep had the largest AUC (Area Under the Curve) in the ROC (Receiver Operating Characteristics) analysis (0.875), providing a cut-off point of 63.20 mm with 95% sensitivity for diagnosis of moderate versus severe OSA. CONCLUSION: Our findings validate the use of DISU in objectively assessing the tongue base collapse in OSA patients. It provides a convenient and non-invasive way to evaluate the upper airway changes in OSA patients in the future.

Dopamine-Initiated Photopolymerization for a Versatile Catechol-Functionalized Hydrogel.

Biomimetic catechol-functionalized hydrogels have attracted substantial attention due to their potential in a variety of biomedical applications, such as tissue repair and regeneration, drug delivery, and antimicrobial and antifouling applications. In this study, a one-pot strategy for fabrication of functional catecholic hydrogels using dopamine as a photoinitiator was developed. Under UV irradiation in an acidic solution, dopamine generates free radicals, likely semiquinone radicals, to trigger the addition polymerization, following pseudo-first-order kinetics. The dopamine-initiated photopolymerization provides a straightforward and facile approach and, in addition, prevents the undesirable oxidation to catecholic groups. Superhydrophilic sulfobetaine methacrylate (SBMA) was applied for developing biocompatible hydrogels. 1H nuclear magnetic resonance, UV-vis spectroscopy, gel permeation chromatography, and rheological studies were conducted to explore the polymerization mechanism and optimal experimental conditions in terms of pH, UV doses, and the concentration of dopamine. The unique properties of the resultant catechol-functionalized pSBMA hydrogels were demonstrated by enhanced mechanical properties through metal-catechol complexation, self-healing and injectable capability, high adhesiveness, and fouling resistance. Consequently, the synthetic strategy to design catecholic hydrogels can leverage the use of dopamine in a variety of applications.