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Background: The role of Akt in nasal immunity is unstudied. Akt phosphorylates and activates endothelial nitric oxide synthase (eNOS) expressed in epithelial ciliated cells. Nitric oxide (NO) production by ciliated cells can have antibacterial and antiviral effects. Increasing nasal NO may be a useful antipathogen strategy in chronic rhinosinusitis (CRS). We previously showed that small‐molecule Akt activator SC79 induces nasal cell NO production and suppresses IL‐8 via the transcription factor Nrf‐2. We hypothesized that SC79 NO production may additionally have antibacterial effects. Methods: NO production was measured using fluorescent dye DAF‐FM. We tested effects of SC79 during co‐culture of Pseudomonas aeruginosa with primary nasal epithelial cells, using CFU counting and live–dead staining to quantify bacterial killing. Pharmacology determined the mechanism of SC79‐induced NO production and tested dependence on Akt. Results: SC79 induced dose‐dependent, Akt‐dependent NO production in nasal epithelial cells. The NO production required eNOS and Akt. The NO released into the airway surface liquid killed P. aeruginosa. No toxicity (LDH release) or inflammatory effects (IL8 transcription) were observed over 24 h. Conclusions: Together, these data suggest multiple immune pathways are stimulated by SC79, with antipathogen effects. This in vitro pilot study suggests that a small‐molecule Akt activator may have clinical utility in CRS or respiratory other infection settings, warranting future in vivo studies. [ABSTRACT FROM AUTHOR]

Introduction: Bitter taste receptors (T2Rs) are G protein-coupled receptors identified on the tongue but expressed all over the body, including in airway cilia and macrophages, where T2Rs serve an immune role. T2R isoforms detect bitter metabolites (quinolones and acyl-homoserine lactones) secreted by gram negative bacteria, including Pseudomonas aeruginosa, a major pathogen in cystic fibrosis (CF). T2R activation by bitter bacterial products triggers calcium-dependent nitric oxide (NO) production. In airway cells, the NO increases mucociliary clearance and has direct antibacterial properties. In macrophages, the same pathway enhances phagocytosis. Because prior studies linked CF with reduced NO, we hypothesized that CF cells may have reduced T2R/NO responses, possibly contributing to reduced innate immunity in CF. Methods: Immunofluorescence, qPCR, and live cell imaging were used to measure T2R localization, calcium and NO signaling, ciliary beating, and antimicrobial responses in air-liquid interface cultures of primary human nasal epithelial cells and immortalized bronchial cell lines. Immunofluorescence and live cell imaging was used to measure T2R signaling and phagocytosis in primary human monocyte-derived macrophages. Results: Primary nasal epithelial cells from both CF and non-CF patients exhibited similar T2R expression, localization, and calcium signals. However, CF cells exhibited reduced NO production also observed in immortalized CFBE41o-CF cells and non-CF 16HBE cells CRISPR modified with CF-causing mutations in the CF transmembrane conductance regulator (CFTR). NO was restored by VX-770/VX-809 corrector/potentiator pre-treatment, suggesting reduced NO in CF cells is due to loss of CFTR function. In nasal cells, reduced NO correlated with reduced ciliary and antibacterial responses. In primary human macrophages, inhibition of CFTR reduced NO production and phagocytosis during T2R stimulation. Conclusions: Together, these data suggest an intrinsic deficiency in T2R/NO signaling caused by loss of CFTR function that may contribute to intrinsic susceptibilities of CF patients to P. aeruginosa and other gram-negative bacteria that activate T2Rs. [ABSTRACT FROM AUTHOR]

T2R bitter taste receptors in airway motile cilia increase ciliary beat frequency (CBF) and nitric oxide (NO) production. Polymorphisms in some T2Rs are linked to disease outcomes in chronic rhinosinusitis (CRS) and cystic fibrosis (CF). We examined the expression of cilia T2Rs during the differentiation of human nasal epithelial cells grown at air–liquid interface (ALI). The T2R expression increased with differentiation but did not vary between CF and non-CF cultures. Treatment with Pseudomonas aeruginosa flagellin decreased the expression of diphenhydramine-responsive T2R14 and 40, among others. Diphenhydramine increased both NO production, measured by fluorescent dye DAF-FM, and CBF, measured via high-speed imaging. Increases in CBF were disrupted after flagellin treatment. Diphenhydramine impaired the growth of lab and clinical strains of P. aeruginosa, a major pathogen in CF and CF-related CRS. Diphenhydramine impaired biofilm formation of P. aeruginosa, measured via crystal violet staining, as well as the surface attachment of P. aeruginosa to CF airway epithelial cells, measured using colony-forming unit counting. Because the T2R agonist diphenhydramine increases NO production and CBF while also decreasing bacterial growth and biofilm production, diphenhydramine-derived compounds may have potential clinical usefulness in CF-related CRS as a topical therapy. However, utilizing T2R agonists as therapeutics within the context of P. aeruginosa infection may require co-treatment with anti-inflammatories to enhance T2R expression. [ABSTRACT FROM AUTHOR]

Airway submucosal gland serous cells are important sites of fluid secretion in conducting airways. Serous cells also express the cystic fibrosis (CF) transmembrane conductance regulator (CFTR). Protease-activated receptor 2 (PAR-2) is a G protein-coupled receptor that activates secretion from intact airway glands. We tested if and how human nasal serous cells secrete fluid in response to PAR-2 stimulation using Ca2+ imaging and simultaneous differential interference contrast imaging to track isosmotic cell shrinking and swelling reflecting activation of solute efflux and influx pathways, respectively. During stimulation of PAR-2, serous cells exhibited dose-dependent increases in intracellular Ca2+. At stimulation levels >EC50 for Ca2+, serous cells simultaneously shrank 20% over 90s due to KCl efflux reflecting Ca2+-activated Cl- channel (CaCC, likely TMEM16A)-dependent secretion. At lower levels of PAR-2 stimulation (50 for Ca2+), shrinkage was not evident due to failure to activate CaCC. Low levels of cAMP-elevating VIP receptor (VIPR) stimulation, also insufficient to activate secretion alone, synergized with low-level PAR-2 stimulation to elicit fluid secretion dependent on both cAMP and Ca2+ to activate CFTR and K+ channels, respectively. Polarized cultures of primary serous cells also exhibited synergistic fluid secretion. Pre-exposure to Pseudomonas aeruginosa conditioned media inhibited PAR-2 activation by proteases but not peptide agonists in primary nasal serous cells, Calu-3 bronchial cells, and primary nasal ciliated cells. Disruption of synergistic CFTR-dependent PAR-2/VIPR secretion may contribute to reduced airway surface liquid in CF. Further disruption of the CFTR-independent component of PAR-2-activated secretion by P. aeruginosa may also be important to CF pathophysiology. [ABSTRACT FROM AUTHOR]

Background: Bitter (T2R) and sweet (T1R) taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38) correlate with disease status and disease severity in chronic rhinosinusitis (CRS). Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS. Methods: Demographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air--liquid interface (ALI). Nitric oxide (NO) production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro. results: Quinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01). Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP) patients rated quinine as significantly less intense than did control subjects. conclusion: Quinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine "insensitivity" is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses. [ABSTRACT FROM AUTHOR]

Background Sinonasal biofilms have been demonstrated in specimens collected from chronic rhinosinusitis (CRS) patients. Mounting evidence suggests that biofilms contribute to therapeutically recalcitrant CRS. Recently, the bitter taste receptor T2R38 has been implicated in the regulation of the sinonasal mucosal innate immune response. TAS2R38 gene polymorphisms affect receptor functionality and contribute to variations seen in sinonasal innate defense as well as taste perception reflected in gustatory sensitivity to the bitter compound phenylthiocarbamide (PTC). In a population of CRS patients with active infection or inflammation, we sought to determine if a correlation between T2R38 phenotype and in vitro biofilm formation existed. Methods Endoscopically guided sinonasal swabs were obtained prospectively from CRS (±polyp) patients with evidence of persistent inflammation or mucopurulence. In vitro biofilm formation was assessed with a modified Calgary Biofilm Detection Assay. Patients' phenotypic (functional) expression of the bitter taste receptor T2R38 was evaluated with a taste test including the compound PTC. Linear regression was used to determine the level of significance between mean in vitro biofilm formation levels and mean PTC taste test intensity ratings across CRS patients. Results Sinonasal swabs were obtained from 59 patients, with 42 of the 59 samples demonstrating in vitro biofilm formation. Analysis revealed an inverse linear association between in vitro biofilm formation and PTC taste intensity ratings ( p = 0.019) for all patients. This association was exclusively driven by nonpolypoid CRS patients ( p = 0.0026). Conclusion In vitro biofilm formation from sinonasal clinical isolates is inversely correlated with PTC taste sensitivity in nonpolypoid CRS patients. [ABSTRACT FROM AUTHOR]

Large cohort studies of chronic rhinosinusitis (CRS) prevalence often include patients who have been inappropriately diagnosed with the disease. In this investigation, new patients presenting to a tertiary rhinology practice completed a screening questionnaire that included questions about self-reported CRS status, demographic information, and symptomatology. Treating rhinologists evaluated patients according to clinical practice guideline criteria for CRS; 91 patients were ultimately diagnosed with CRS. The sensitivity of self-report for CRS was 84%; the specificity was 82%; and the estimated negative predictive value ranged from 97% to 99%. Prior sinus surgery or oral steroid use correlated with CRS self-report, and a concurrent self-report of nasal polyps or nasal steroid use improved the positive predictive value of CRS self-report. Self-report of CRS status may represent an effective and relatively inexpensive screening mechanism for CRS in large cohort studies, particularly when combined with other associated diagnostic features that improve performance parameters of self-report. [ABSTRACT FROM AUTHOR]

Background: T2R bitter taste receptors play a crucial role in sinonasal innate immunity by upregulating mucociliary clearance and nitric oxide (NO) production in response to bitter gram-negative quorum-sensing molecules in the airway surface liquid. Previous studies showed that phytochemical flavonoid metabolites, known as anthocyanidins, taste bitter and have antibacterial effects. Our objectives were to examine the effects of anthocyanidins on NO production by human sinonasal epithelial cells and ciliary beat frequency, and their impact on common sinonasal pathogens Pseudomonas aeruginosa and Staphylococcus aureus. Methods: Ciliary beat frequency and NO production were measured by using digital imaging of differentiated air-liquid interface cultures prepared from primary human cells isolated from residual surgical material. Plate-based assays were used to determine the effects of anthocyanidins on bacterial swimming and swarming motility. Biofilm formation and planktonic growth were also assessed. Results: Anthocyanidin compounds triggered epithelial cells to produce NO but not through T2R receptors. However, anthocyanidins did not impact ciliary beat frequency. Furthermore, they did not reduce biofilm formation or planktonic growth of P. aeruginosa. In S. aureus, they did not reduce planktonic growth, and only one compound had minimal antibiofilm effects. The anthocyanidin delphinidin and anthocyanin keracyanin were found to promote bacterial swimming, whereas anthocyanidin cyanidin and flavonoid myricetin did not. No compounds that were tested inhibited bacterial swarming. Conclusion: Results of this study indicated that, although anthocyanidins may elicited an innate immune NO response from human cells, they do not cause an increase in ciliary beating and they may also cause a pathogenicity-enhancing effect in P. aeruginosa. Additional studies are necessary to understand how this would affect the use of anthocyanidins as therapeutics. This study emphasized the usefulness of in vitro screening of candidate compounds against multiple parameters of both epithelial and bacterial physiologies to prioritize candidates for in vivo therapeutic testing. [ABSTRACT FROM AUTHOR]

Background Chronic rhinosinusitis (CRS) is very prevalent in the cystic fibrosis (CF) patient population, and leads to high morbidity and markedly decreased quality of life (QOL). Identification of genetic markers that contribute to CRS symptoms in these patients can allow for risk stratification and tailoring of medical and surgical treatments. T2R38 is a bitter taste receptor expressed in the sinonasal tract, and nonfunctional alleles of this receptor have been implicated in treatment-refractory CRS in non-CF patients. The purpose of this study is to investigate the significance of T2R38 genotype in the variability of sinonasal QOL and CRS disease severity in a sample of CF patients. Methods ΔF508 homozygous CF patients were recruited from the University of Pennsylvania Cystic Fibrosis Center and were genotyped for the TAS2R38 locus. To assess sinonasal symptom severity, a 22-item Sino-Nasal Outcome Test (SNOT-22) was collected from each patient. Additional demographic and medical history data was obtained at the time of patient enrollment. Results A total of 49 ΔF508 homozygous CF patients aged 18 to 32 years were included in the final SNOT-22 score analysis. Individuals with 2 functional T2R38 alleles (PAV/PAV) had significantly lower SNOT-22 scores (n = 49, p < 0.05). On further breakdown of SNOT-22 subcategories, rhinologic symptoms specifically were less severe in PAV/PAV patients than patients with other genotypes (n = 47, p < 0.05). Conclusion Our investigation indicates that T2R38 genotype correlates both with SNOT-22 scores and rhinologic-specific QOL in ΔF508 homozygous CF patients. [ABSTRACT FROM AUTHOR]

Purpose: Concha bullosa (CB) alters the intranasal anatomy and may influence the buffering of inhalant allergens and the inflammatory microenvironment central to chronic rhinosinusitis (CRS). By investigating the link between allergies and CB, we can examine this theoretical benefit, which has implications on the extent of resection in endoscopic sinus surgery.Methods: Forty-three adults treated between 2010 and March 2014 with chronic sinonasal symptoms were retrospectively analyzed by skin prick allergy testing, maxillofacial computed tomography scan, and Lund-Mackay score. x03C7;2 analysis and t tests were employed to determine statistical significance.Results: Subjects were divided into 30 positive cases and 13 pan-negative allergy controls. No difference in CB prevalence was observed between those with positive (70%) and those with negative (69.2%) allergy tests (p = 0.93). Furthermore, no association between CB and Lund-Mackay score was identified (p = 0.69). Overall, 83.3% of CB were located in the middle turbinate, 16.7% in the superior turbinate, and 20% occurred in the middle turbinate bilaterally.Conclusions: Although an enlarged, pneumatized turbinate could function as a physical barrier to inhalant allergens, documented allergies demonstrate no association with CB formation. Furthermore, this study finds no correlation between CB and radiographic evidence of CRS. [ABSTRACT FROM AUTHOR]

Background Staphylococcus aureus and Pseudomonas aeruginosa are common culture isolates in chronic rhinosinusitis (CRS). We aimed to determine whether they were associated with different clinical factors of CRS. Methods Adult CRS patients who underwent functional endoscopic sinus surgery (FESS) between October 1, 2007 and December 31, 2011 were recruited. Patient demographics, Lund-Mackay computed tomography (CT) scores, 22-item Sino-Nasal Outcome Test (SNOT-22) scores, disease characteristics, and medication use were collected prior to FESS. Intraoperative culture was obtained in a standard manner. We compared patients with isolates of S. aureus or P. aeruginosa to patients with other culture results and no bacterial growth, respectively. Multivariate logistic regression was performed. Results A total of 376 patients met criteria; 104 patients (28%) had S. aureus, 32 (9%) had P. aeruginosa, and 10 patients (3%) had no bacterial growth. After adjusting for all clinical factors, compared to patients with positive culture other than S. aureus, patients with S. aureus had 1.9 times increased odds of having nasal polyps (odds ratio [OR] = 1.9; 95% confidence interval [CI], 1.0 to 3.3; p = 0.036); when compared to patients with positive culture other than P. aeruginosa, patients with P. aeruginosa had 7.8 times increased odds of having prior FESS (OR = 7.8; 95% CI, 2.1 to 28.9; p = 0.002) (91% vs 58%; p < 0.001) and 3.6 times increased odds of having diabetes with marginal significance (OR = 3.6; 95% CI, 1.0 to 13.2; p = 0.053). The sample size in the no bacterial growth group was too small to draw firm conclusions. Conclusion S. aureus was more common in CRS patients with nasal polyps, whereas P. aeruginosa was more common in CRS patients with prior FESS history and possibly diabetes. [ABSTRACT FROM AUTHOR]

Background It remains unclear how much chronic rhinosinusitis (CRS) patients with bacterial biofilms can benefit from functional endoscopic sinus surgery (FESS). We aimed to evaluate whether biofilm-forming bacteria was associated with quality of life (QOL) improvement after FESS. Methods This retrospective cohort study included adult CRS patients who underwent FESS from 2008 to 2011. Sinus samples were taken to evaluate for biofilm-formation in vitro using a modified Calgary Biofilm Detection Assay. QOL was measured before FESS, and 1-month, 3-month, and 6-month after FESS using 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Patients' characteristics and medications were collected. Clinical significant QOL change was defined as a difference of at least 0.5 standard deviation (SD) of baseline SNOT-22 score in the reference group. Results A total of 156 patients had complete data, and 15% had biofilm-forming bacteria (n = 24). Patients with biofilm-forming bacteria had significantly worse preoperative SNOT-22 scores compared to patients without biofilm-forming bacteria (48 ± 20 vs 38 ± 23, p = 0.048). Both groups had clinically significant QOL improvement after FESS, and the differences in their 1-month (23 ± 19 vs 17 ± 20) and 3-month (27 ± 18 vs 18 ± 19) post-FESS SNOT-22 scores were not significant. However, patients with biofilm-forming bacteria demonstrated significantly less QOL improvement than patients without biofilm-forming bacteria from pre-FESS to 6-month post-FESS visits after adjusting for clinical factors (35 ± 25 vs 14 ± 15; β-coefficient = 0.71; 95% confidence interval [CI], 0.13 to 1.28; p = 0.016). Conclusion CRS patients with biofilm-forming bacteria demonstrated clinically significant QOL improvement following FESS, but the degree of improvement was decreased overtime and became significantly worse than patients without biofilm-forming bacteria by 6-month follow-up. This QOL worsening was independent of other risk factors for CRS. [ABSTRACT FROM AUTHOR]

Background Coagulase-negative Staphylococcus (CoNS) is commonly isolated from patients with chronic rhinosinusitis (CRS). However, the role of CoNS in CRS remains controversial. We aimed to determine the association between positive CoNS culture at functional endoscopic sinus surgery (FESS) and CRS severity. Methods Adult CRS patients who underwent FESS between October 1, 2007 to December 31, 2011 were recruited. Patient demographics, disease characteristics, medication use, Lund-Mackay computed tomography (CT) scores, and 22-item Sino-Nasal Outcome Test (SNOT-22) scores were collected at baseline before FESS. Intraoperative cultures were obtained in a standard manner. Patients were placed into 2 groups based on culture findings: patients with CoNS as the sole positive culture result and patients with all other positive culture results, including CoNS, as part of a polymicrobial culture. Results A total of 376 CRS patients met the criteria; 106 patients (28%) had CoNS as their only isolate, 260 (69%) had other positive cultures, and 10 (3%) had no bacterial growth. Compared to patients with other positive cultures, patients with the sole result of CoNS were significantly less likely to have a history of FESS (52% vs 65%, p = 0.019), nasal polyps (50% vs 65%, p = 0.006), and had a better Lund-Mackay CT score (11.95 vs 14.18, p = 0.020). After adjusting for all factors in the multiple logistic regression model, CoNS as the sole positive culture result was independently associated with having no history of FESS (odds ratio [OR] = 0.45; 95% confidence interval [CI], 0.22 to 0.94; p = 0.034). Conclusion Positive intraoperative CoNS cultures alone do not result in increased CRS disease burden by objective or subjective measures as compared to patients with other bacterial or polymicrobial culture isolates. [ABSTRACT FROM AUTHOR]

Background It is unclear whether chronic rhinosinusitis (CRS) patients with both nasal polyps and asthma have different quality of life (QOL) improvement after functional endoscopic sinus surgery (FESS). We aimed to determine whether CRS patients with asthma and nasal polyps had a greater QOL improvement after FESS compared to patients without asthma or polyps. Methods This retrospective analysis included adult CRS patients who underwent FESS between 2007 and 2011. QOL was measured using the 22-item Sino-Nasal Outcome Test (SNOT-22). Variables collected included baseline demographics, clinical factors, SNOT-22 scores before FESS, and 1 month, 3 months, and 6 months post-FESS. Groups tested were asthma alone, polyps alone, asthma and polyps, and no asthma or polyps. Linear mixed-effects regression model was performed to calculate β-coefficients, which represent the adjusted mean QOL differences. Results Among the 376 patients included, 40.16% had both asthma and polyps (n = 151), 14.36% had asthma alone (n = 54), 19.45% had polyps alone (n = 75), and 25.53% had no asthma or polyps (n = 96). After adjusting for all factors, there were significantly more QOL improvements in patients with both asthma and nasal polyps from baseline to 1-month (β-coefficient = −10.05; 95% CI, −15.86 to −4.23; p = 0.001) and 3-month follow-up (β-coefficient = −8.27; 95% CI, −14.98 to −1.56; p = 0.016), and patients with asthma alone from baseline to 6-month follow-up (β-coefficient = −8.78; 95% CI, −17.45 to −0.11; p = 0.047), when compared to patients without asthma or nasal polyps. Conclusion CRS patients with both asthma and nasal polyps or asthma alone experience a larger QOL benefit from FESS immediately after FESS compared to CRS patients without asthma or polyps. [ABSTRACT FROM AUTHOR]

Background Patients with diabetes mellitus (DM) are known to be prone to infection. However, the association between diabetes and chronic rhinosinusitis (CRS) has not been well studied. We sought to determine the effects of DM on CRS culture results and quality of life (QOL) after functional endoscopic sinus surgery (FESS). Methods We conducted a retrospective cohort study. Adult CRS patients undergoing FESS were recruited from October 1, 2007 to December 31, 2011. Patient demographics, comorbidities, medication use, and Lund-Mackay CT scores were collected prior to FESS. Intraoperative culture was obtained. Preoperative and 1-month, 3-month, and 6-month postoperative QOL was measured by scores on the 22-item Sinonasal Outcome Test (SNOT-22). A mixed effects model was performed for analysis. Results Among the 376 CRS patients included, 19 patients (5.05%) had DM. Compared to non-DM patients, DM patients were significantly more likely to have Pseudomonas aeruginosa (26.32% vs 7.56%; p = 0.004) and Gram-negative rods (26.32% vs 8.96%; p = 0.013), but there was no significant difference in the prevalence of Staphylococcus aureus; DM patients were also significantly more likely to have nasal polyps and gastroesophageal reflux disease. Additionally, DM patients had significantly less improvement of postoperative SNOT-22 scores from baseline to 6-month follow-up than non-DM patients (adjusted mean = 11.14, 95% CI (0.14, 22.15), p = 0.047) after adjusting for all the other risk factors for CRS. Conclusion DM patients may be prone to Gram-negative bacterial sinus infections, and have significantly worse short-term postoperative QOL. Special postoperative care may need to be considered in CRS patients with DM. [ABSTRACT FROM AUTHOR]

Mucociliary clearance (MCC) is the primary physical airway defense against inhaled pathogens and particulates. MCC depends on both proper fluid/ mucus homeostasis and epithelial ciliary beating. Vasoactive intestinal peptide (VIP) is a neurotransmitter expressed in the sinonasal epithelium that is up-regulated in allergy. However, the effects of VIP on human sinonasal physiology are unknown, as are VIP's interactions with histamine, a major regulator of allergic disease. We imaged ciliary beat frequency, mucociliary transport, apical Cl- permeability, and airway surface liquid (ASL) height in primary human sinonasal air-liquid-interface cultures to investigate the effects of VIP and histamine. VIP stimulated an increase in ciliary beat frequency (EC50 0.5 µM; maximal increase -40% compared with control) and cystic fibrosis transmem-brane conductance regulator (CFFR)-dependent and Na+K+2Cl- cotransporter-dependent fluid secretion, all requiring cAMP/PKA signaling. Histamine activated Ca2+ signaling that increased ASL height but not ciliary beating. Low concentrations of VIP and histamine had synergistic effects on CFrR-dependent fluid secretion, revealed by increased ASL heights. An up-regulation of VIP in histamine-driven allergic rhinitis would likely enhance mucosal fluid secretion and contribute to allergic rhinorrhea. Conversely, a loss of VIP-activated secretion in patients with CF may impair mucociliary transport, contributing to increased incidences of sino-nasal infections and rhinosinusitis. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis To determine whether the use of topical nasal therapies with saline alone and in combination with antibiotics, antifungals, or corticosteroids is effective in the treatment of patients with chronic rhinosinusitis (CRS). Data Sources A systematic literature search was performed utilizing the MEDLINE database (1966 to May 2012), EMBASE database (1980 to May 2012), and the Cochrane Central Register of Controlled Trials. Review Methods Electronic databases were searched by three otolaryngologists. Studies on five major categories of topical nasal therapies searched included saline (hypotonic, isotonic and hypertonic); topical antibiotics, topical steroids, and topical antifungals were obtained. Randomized controlled trials and meta-analyses of randomized controlled trials were included. Results Sixteen randomized controlled trials were identified examining topical saline (hypertonic or isotonic) in CRS patients. Two randomized controlled trials were found studying the effect of topical antibiotics in patients with CRS. Four randomized controlled trials were identified studying topical antifungal treatment for CRS. Twenty-five randomized controlled trials were found studying topical steroids in CRS patients. Conclusion A high aggregate quality of evidence supports the effectiveness of saline irrigations in treating CRS. There is insufficient evidence to support a clear benefit of topical antibiotics in patients with chronic rhinosinusitis. Topical antifungal therapies have not been shown to be significantly different in efficacy than saline controls on CRS outcomes. Topical steroids are beneficial in the treatment of CRS with nasal polyps, but have not been shown to be effective in CRS without nasal polyps. Laryngoscope, 123:2347-2359, 2013 [ABSTRACT FROM AUTHOR]

• De-ciliated squamous airway cells express intracellular T2R bitter taste receptors. • Intracellular bitter taste receptors activate nuclear and mitochondrial calcium elevation. • Calcium elevation causes depolarization of mitochondrial membrane and caspase activation. • Blocking calcium signaling prevents apoptosis. Bitter taste receptors (T2Rs) localize to airway motile cilia and initiate innate immune responses in retaliation to bacterial quorum sensing molecules. Activation of cilia T2Rs leads to calcium-driven NO production that increases cilia beating and directly kills bacteria. Several diseases, including chronic rhinosinusitis, COPD, and cystic fibrosis, are characterized by loss of motile cilia and/or squamous metaplasia. To understand T2R function within the altered landscape of airway disease, we studied T2Rs in non-ciliated airway cell lines and primary cells. Several T2Rs localize to the nucleus in de-differentiated cells that typically localize to cilia in differentiated cells. As cilia and nuclear import utilize shared proteins, some T2Rs may target to the nucleus in the absence of motile cilia. T2R agonists selectively elevated nuclear and mitochondrial calcium through a G-protein-coupled receptor phospholipase C mechanism. Additionally, T2R agonists decreased nuclear cAMP, increased nitric oxide, and increased cGMP, consistent with T2R signaling. Furthermore, exposure to T2R agonists led to nuclear calcium-induced mitochondrial depolarization and caspase activation. T2R agonists induced apoptosis in primary bronchial and nasal cells differentiated at air-liquid interface but then induced to a squamous phenotype by apical submersion. Air-exposed well-differentiated cells did not die. This may be a last-resort defense against bacterial infection. However, it may also increase susceptibility of de-differentiated or remodeled epithelia to damage by bacterial metabolites. Moreover, the T2R-activated apoptosis pathway occurs in airway cancer cells. T2Rs may thus contribute to microbiome-tumor cell crosstalk in airway cancers. Targeting T2Rs may be useful for activating cancer cell apoptosis while sparing surrounding tissue. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Succinate, although most famous for its role in the Krebs cycle, can be released extracellularly as a signal of cellular distress, particularly in situations of metabolic stress and inflammation. Solitary chemosensory cells (SCCs) express SUCNR1, the succinate receptor, and modulate type 2 inflammatory responses in helminth and protozoal infections in the small intestine. SCCs are the dominant epithelial source of interleukin‐25, as well as an important source of cysteinyl leukotrienes in the airway, and have been implicated as upstream agents in type 2 inflammation in chronic rhinosinusitis (CRS) and asthma. Methods: In this study, we used scRNAseq analysis, live cell imaging of intracellular calcium from primary sinonasal air‐liquid interface (ALI) cultures from 1 donor, and measure antimicrobial peptide release from 5 donors to demonstrate preliminary evidence suggesting that succinate can act as a stimulant of SCCs in the human sinonasal epithelium. Results: Results from scRNAseq analysis show that approximately 10% of the SCC/ionocyte cluster of cells expressed SUCNR1 as well as a small population of immune cells. Using live cell imaging of intracellular calcium, we also demonstrate that clusters of cells on primary sinonasal ALI cultures initiated calcium‐mediated signaling in response to succinate stimulation. Furthermore, we present evidence that primary sinonasal ALI cultures treated with succinate had increased levels of apical beta‐defensin 2, an antimicrobial peptide, compared to treatment with a control solution. Conclusion: Overall, these findings demonstrate the need for further investigation into the activation of the sinonasal epithelium by succinate in the pathogenesis of CRS. [ABSTRACT FROM AUTHOR]

AERD subjects demonstrated increased sensitivity to DB ( I p i < 0.01) and sucrose ( I p i < 0.01) compared with CRSsNP, while CRSsNP subjects demonstrated a reduced sensitivity to DB ( I p i < 0.05) and sucrose ( I p i < 0.05) compared with controls (Figure 1). It was anticipated that in AERD, unique genetic polymorphisms in DB-responsive T2Rs may result in upregulation of the receptors and resulting type-2 inflammation. Keywords: aspirin-exacerbated respiratory disease; bitter; chronic rhinosinusitis; gene; open array; sensory; taste EN aspirin-exacerbated respiratory disease bitter chronic rhinosinusitis gene open array sensory taste 269 272 4 02/21/23 20230301 NES 230301 INTRODUCTION Chronic rhinosinusitis (CRS), a disease of long-standing sinonasal inflammation, is divided into two phenotypes: CRS with and without nasal polyposis (CRSwNP, CRSsNP). [Extracted from the article]

Background Antimicrobial peptides (AMPs) produced by the epithelium are important for innate immune defense. In 2001, a novel AMP dermcidin (DCD) was described with no homology to other AMPs and an expression pattern restricted to eccrine sweat glands. In contrast to other AMPs, DCD expression has not been shown to be induced under inflammatory conditions in the skin. After identifying DCD by mass spectrometry in a protein sample isolated from human nasal secretions, we sought to determine the role of DCD in innate defense of the sinonasal airway. Methods After institutional review board approval, sinonasal mucosal tissue specimens were acquired from residual clinical material obtained during sinonasal surgery and used to grow cultures in an air-liquid interface environment. After stimulation of the cultures with various bitter compounds and phosphate-buffered saline, airway surface liquid was collected, and a DCD-specific enzyme-linked immunoassay was used to quantify DCD in each sample. To localize DCD expression, ALI cultures were fixed and immunofluorescence performed against DCD, β-tubulin IV, and Muc-5A. Results Enzyme-linked immunoassay showed DCD in air-surface liquid and in clinical nasal secretion samples at concentrations comparable to eccrine sweat. There was no evidence of inducible expression with any of the tested stimulants. Confocal microscopy revealed DCD expression in sinonasal mucosal goblet cells. Conclusion This is the first report of the presence of DCD in nasal mucosa and demonstration of DCD in clinical samples of human nasal secretions at clinically relevant concentrations, which may represent a novel arm of sinonasal airway innate defense. [ABSTRACT FROM AUTHOR]

Background Nitric oxide (NO) is produced by sinonasal epithelial cells as part of the innate immune response against bacteria. We previously described bitter-taste-receptor-dependent and -independent NO responses to product(s) secreted by Pseudomonas aeruginosa and Staphylococcus aureus, respectively. We hypothesized that sinonasal epithelium would be able to detect the gram-positive, coagulase-negative bacteria Staphylococcus epidermidis and mount a similar NO response. Methods Sinonasal air-liquid interface cultures were treated with conditioned medium (CM) from lab strains and clinical isolates of coagulase-negative staphylococci and S aureus. NO production was quantified by fluorescence imaging. Bitter taste receptor signaling inhibitors were utilized to characterize the pathway responsible for NO production in response to S epidermidis CM. Results S epidermidis CM contains a low-molecular-weight, heat, and protease-stabile product that induces an NO synthase (NOS)-mediated NO production that is less robust than the response triggered by S aureus CM. The S epidermidis CM-stimulated NO response is not inhibited by antagonists of phospholipase C isoform β-2 nor the transient receptor potential melastatin isoform 5 ion channel, both critical to bitter taste signaling. Conclusion This study identifies an NO-mediated innate defense response in sinonasal epithelium elicited by S epidermidis product(s). The active bacterial product is likely a small, nonpeptide molecule that stimulates a pathway independent of bitter taste receptors. Although the NO response to S epidermidis is less vigorous compared with S aureus, the product(s) share similar characteristics. Together, the responses to staphylococci species may help explain the pathophysiology of upper respiratory infections. [ABSTRACT FROM AUTHOR]

CRSwNP can be further subcategorized into endotypes including aspirin-exacerbated respiratory disease (AERD), allergic fungal rhinosinusitis (AFRS), and, recently, central compartment atopic disease (CCAD) has been proposed as a novel endotype.2 There is a complex relationship between allergic rhinitis (AR) and CRS3; one potential link may be CCAD. Keywords: allergens; allergic rhinitis; chronic rhinosinusitis; skin prick testing EN allergens allergic rhinitis chronic rhinosinusitis skin prick testing 1299 1302 4 09/30/22 20221001 NES 221001 INTRODUCTION Chronic rhinosinusitis (CRS) is an inflammatory condition of the nose and paranasal sinuses that persists for greater than 12 weeks.1 CRS has traditionally been categorized based on the presence (CRSwNP) or absence (CRSsNP) of nasal polyps. There was no statistically significant difference in the inhalant allergen sensitization profiles of patients with AR and CCAD, except for a higher prevalence of weed allergy in the CCAD group, which barely reached statistical significance. [Extracted from the article]

Background: Cystic fibrosis (CF) chronic rhinosinusitis (CRS) has emerged as a distinct diagnostic entity, unique from other endotypes of CRS in its presentation, pathophysiology, diagnosis, treatment, and outcomes. As the sinonasal health of this patient population may have broad effects on pulmonary health and quality of life, a comprehensive understanding of the diagnostic and therapeutic approach to CF CRS is essential. In recognizing recent scientific advances and unique treatment modalities specific to this challenging patient population, in this review we systematically evaluate the scientific literature and provide an evidenced‐based review with recommendations (EBRR) for fundamental management principles of CF CRS. Methods: A systematic review of the literature was performed. Studies evaluating interventions for the management of CF CRS were included. An iterative review process was implemented in accordance with EBRR guidelines. A treatment recommendation was generated based on an assessment of the benefits, harms, and the overall grade of evidence. Results: We evaluated the published literature on 5 unique topics. Each of the following therapeutic categories was investigated explicitly for treatment outcomes in patients with CF CRS: (1) nasal saline; (2) intranasal corticosteroids (INCS); (3) topical antibiotics; (4) cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy; and (5) endoscopic sinus surgery (ESS). Conclusion: Based on the currently available evidence, nasal saline, ESS, and CFTR modulators are recommended in the management of CF CRS when appropriate. INCS and topical antibiotics are options. Clinical judgment and experience are essential in caring for patients with this uniquely challenging disorder. [ABSTRACT FROM AUTHOR]

We tracked patient SNOT-22 and ACT scores at the following time-points: post-FESS/pre-desensitization; 1 to 3 months post-desensitization; 4 to 6 months post-desensitization; 7 to 12 months post-desensitization; and 13 to 24 months post-desensitization. Values for age, daily prednisone dose, and pre-desensitization SNOT-22 were recorded after FESS and before aspirin treatment after aspirin desensitization. Keywords: chronic rhinosinusitis; endoscopic sinus surgery; eosinophilic rhinitis and nasal polyposis; FESS; SNOT-22 EN chronic rhinosinusitis endoscopic sinus surgery eosinophilic rhinitis and nasal polyposis FESS SNOT-22 872 875 4 05/17/22 20220601 NES 220601 Aspirin-exacerbated respiratory disease (AERD) is a chronic inflammatory condition characterized by the triad of eosinophilic asthma, chronic rhinosinusitis with nasal polyposis, and a non-IgE-mediated hypersensitivity to nonsteroidal anti-inflammatory drugs.1 The "gold standard" treatment of AERD consists of debulking of nasal polyps via complete functional endoscopic sinus surgery (FESS) of all 8 sinuses followed by aspirin treatment after aspirin desensitization (ATAD).2 The treatment protocol has been shown to lead to improved score on the 22-item Sino-Nasal Outcome Test (SNOT-22), decreased overall corticosteroid use, lower rate of revision surgery, and improved control of asthma.3,4 In this study, we seek to compare the outcomes of ATAD between men and women with AERD. [Extracted from the article]

Background: Chronic rhinosinusitis (CRS) is a multifactorial disease with a high co‐occurrence with asthma. In this multicohort study, we tested whether single nucleotide polymorphisms (SNPs) associated with childhood asthma and rhinovirus (RV)‐associated disease are related to an increased susceptibility to adult CRS in a multicohort retrospective case‐control study. Methods: Participants at two tertiary academic rhinology centers, University of Arizona (UofA) and University of Pennsylvania (UPenn) were recruited. Cases were defined as those with physician diagnosed CRS (UofA, n = 149; UPenn, n = 250), and healthy controls were those without CRS (UofA, n = 66; UPenn, n = 275). Genomic DNA was screened for the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP. Gene dosage, or the number of combined risk alleles in a single subject was calculated. Meta‐analysis of the association between GSDMB or CDHR3 genotypes and CRS was performed and additive gene dosage effect for each population calculated using p for trend. Results: A meta‐analysis revealed a combined increased risk for CRS in subjects with the GSDMB rs7216389 SNP (odds ratio [OR] 1.40; 95% confidence interval [CI], 1.16–1.76; p = 0.004). Both the UofA (OR 1.73; 95% CI, 1.23–2.43; p = 0.002) and UPenn (OR 1.27; 95% CI, 1.02–1.58; p = 0.035) populations showed a significant positive association between the number of combined risk alleles of GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP and risk for CRS. Conclusion: Carriers of the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP are at increased susceptibility for CRS. These data suggest that therapeutic approaches to target aberrant responses to RV infection may play a role in the treatment of unified airway disease. [ABSTRACT FROM AUTHOR]

Keywords: chronic rhinosinusitis; human leukocyte antigen; rhinosinusitis; sinusitis EN chronic rhinosinusitis human leukocyte antigen rhinosinusitis sinusitis 1075 1077 3 07/27/22 20220801 NES 220801 INTRODUCTION Chronic rhinosinusitis (CRS), an extremely common chronic condition, is defined as symptomatic and objective inflammation of the sinonasal mucosa lasting more than 12 weeks.1,2 Treatment for CRS remains a challenge despite our evolving understanding of the underlying mechanisms. RESULTS The 550 patients comprised 317 CRS patients (208 CRSwNP, 109 CRSsNP) and 233 controls (Table 1), all self-identified as white/Caucasian and middle-aged. In summary, we have determined that heterozygous carriers of the rs1391371 T allele are at significantly increased risk for developing CRSwNP, which further supports the potential contribution of this HLA region to CRS. [Extracted from the article]

Background: Bitter and sweet taste receptors are present in the human upper airway, where they have roles in innate immunity. Previous studies have shown that 1 of the 25 bitter receptors, TAS2R38, responds to specific bacterial signaling molecules and evokes 1 type of a defense response in the upper airway, whereas ligands of sweet receptors suppress other types of defense responses. Methods: We examined whether other bitter taste receptors might also be involved in innate immunity by using sensory responses to bitter compounds that are not ligands of TAS2R38 (quinine and denatonium benzoate) to assess the sensitivity of other bitter receptors in chronic rhinosinusitis (CRS) patients. CRS patients with (n = 426) and without (n = 226) nasal polyps and controls (n = 356) rated the intensity of quinine, denatonium benzoate, phenylthiocarbamide (PTC; a ligand for TAS2R38), sucrose, and salt. Results: CRS patients rated the bitter compounds denatonium benzoate and quinine as less intense and sucrose as more intense than did controls (false discovery rate [FDR] <0.05) and CRS patients and controls did not differ in their ratings of salt (FDR >0.05). PTC bitter taste intensity differed between patient and control groups but were less marked than those previously reported. Though differences were statistically significant, overall effect sizes were small. Conclusion: CRS patients report bitter stimuli as less intense but sweet stimuli as more intense than do control subjects. We speculate that taste responses may reflect the competence of sinonasal innate immunity mediated by taste receptor function, and thus a taste test may have potential for clinical utility in CRS patients. [ABSTRACT FROM AUTHOR]

Background: Treatment of aspirin‐exacerbated respiratory disease (AERD) includes endoscopic sinus surgery (ESS) and aspirin desensitization (AD) with aspirin therapy after desensitization (ATAD). The objective of this study was to determine the rate of major complications associated with aspirin use that resulted in the discontinuation of aspirin therapy. Methods: This study was a retrospective chart review of patients with AERD who underwent ESS, AD, and ATAD at a single AERD tertiary center between July 2016 and February 2019. Complications associated with aspirin that resulted in the discontinuation of aspirin therapy were analyzed via analysis of variance and logistic regression. Results: In total, 109 AERD patients underwent ESS with subsequent AD. Ten patients (9.2%) discontinued therapy after AD, before starting ATAD. Eight patients (7.3%) discontinued therapy after starting ATAD. There were 91 patients (83.5%) with no complications throughout ATAD. Reasons for discontinuation included gastritis, upper gastrointestinal (GI) bleed, anaphylaxis, persistent sinonasal symptoms, recurrent epistaxis, asthma exacerbation, and a nummular rash. There was no significant correlation between complication rate and (1) aspirin doses (analysis of variance [ANOVA] F: 0.69; p = 0.51), (2) gender (odds ratio [OR] 0.56; 95% confidence interval [CI], 0.19 to 1.65; p = 0.30), (3) age (OR 1.04; 95% CI, 0.96 to 1.09; p = 0.06), or (4) race/ethnicity (OR 1.12; 95% CI, 0.88 to 1.44; p = 0.36). Conclusion: AD with ATAD was associated with only a 0.92% incidence of a clinically significant GI bleed, and only a 0.92% incidence of anaphylaxis. A remaining 16 patients (14.7%) discontinued aspirin therapy due to minor clinical sequelae. These findings demonstrate that the majority of AERD patients tolerate AD with ATAD without any major complications. [ABSTRACT FROM AUTHOR]

Background: The pathogenesis of inverted papilloma (IP) has not been fully elucidated. However, chronic paranasal sinus inflammation has been anecdotally observed in sites distant from tumor obstruction in IP patients, suggesting an association between inflammation and IP tumorigenesis. This study assesses the association between sinonasal inflammation found in IP and compares this to the level of inflammation observed in other sinonasal tumors. Methods: A retrospective chart review was performed identifying patients with unilateral IP. Pertinent clinical data was obtained and comparative analysis of preoperative computed tomography (CT) imaging and histopathology was performed. A sample of unilateral, sinonasal, non‐IP and non–squamous cell tumors was used as the control. The Lund‐Mackay scoring system was used to assess radiologic sinonasal inflammation both ipsilateral and contralateral to the tumor. Results: Seventy‐one patients were included; 58.9% of patients with IP had evidence of contralateral sinusitis at the time of presentation. In the control group, 26.7% had evidence of contralateral inflammation. When comparing contralateral sinus inflammation between the 2 study groups, the IP patients had significantly higher Lund‐Mackay scores than the control group (1.9 vs 0.26, p < 0.001). When comparing ipsilateral sinus inflammation, no significant difference was found in Lund‐Mackay scores (5.44 vs 4.00, p < 0.184). Conclusion: In this study, unilateral IPs were associated with a higher level of contralateral sinonasal inflammation when compared to control. This suggests that IP may be associated with inflammation that is independent of obstruction by the tumor. Further studies are needed to better understand the temporal relationship between chronic inflammation and tumorigenesis. [ABSTRACT FROM AUTHOR]

Keywords: cystic fibrosis; CFTR modulator; elexacaftor; tezacaftor; ivacaftor; chronic rhinosinusitis; sinus surgery; SNOT-22 EN cystic fibrosis CFTR modulator elexacaftor tezacaftor ivacaftor chronic rhinosinusitis sinus surgery SNOT-22 201 203 3 02/24/21 20210201 NES 210201 Cystic fibrosis (CF) is a genetic condition caused by an abnormality in the cystic fibrosis transmembrane conductance regulator (CFTR) causing recurrent pulmonary infections, pancreatic insufficiency, and, from an otolaryngology perspective, chronic rhinosinusitis (CRS).1 Symptoms are recalcitrant to medical therapies, and over 20% of CF patients require endoscopic sinus surgery (ESS) to address sinonasal complaints. All patients on CFTR modulators before ELX/TEZ/IVA were DF508 homozygotes on either TEZ/IVA or LUM/IVA. In summary, the novel highly-effective CFTR modulator ELX/TEZ/IVA leads to significantly improved sinonasal QoL in CF adults as measured by the SNOT-22 questionnaire. [Extracted from the article]

Background: Intranasal steroids have become part of the mainstay in the long‐term management of chronic rhinosinusitis. A long‐standing problem remains in efficient and easy‐to‐use delivery of topical corticosteroids to the nasal mucosa. Currently available means of intranasal steroid delivery include sprays, which are generally limited to treating the anterior nasal cavity, and rinses, which are not FDA‐approved for this indication. The exhalation delivery system is a novel method of delivering fluticasone to the deeper areas within the nasal cavities, including the posterior nasal cavity and middle and superior meatuses. Methods: Comprehensive literature review. Results: Recent large scale studies have suggested its efficacy and safety in the use of patients with both chronic sinusitis with polyposis and without polyps. Specifically, studies have demonstrated decreased Sinonasal Outcome Test scores of 20 points following treatment, as well as improvement of polyp grade by 1 or more point in more than 60% of patients. Furthermore, among patients with nasal polyps, there was approximately 60‐70% decreased indication for surgery following EDS‐FLU use. Conclusion: EDS‐FLU is an important adjunct therapy for sinonasal inflammatory disease. [ABSTRACT FROM AUTHOR]

Background: Aspirin‐exacerbated respiratory disease (AERD) is characterized by chronic eosinophilic rhinosinusitis, nasal polyps, asthma, and respiratory sensitivity to aspirin and nonsteroidal anti‐inflammatory drugs (NSAIDs). In addition to sensitivity to aspirin and NSAIDs, the majority of patients with AERD have been reported to have respiratory intolerance associated with the consumption of alcohol. Methods: A multicenter prospective cohort study was performed. Patients with AERD confirmed by aspirin challenge were eligible to participate. Those who described themselves as able to tolerate alcohol consumption were excluded. Patients underwent aspirin desensitization following endoscopic sinus surgery. A questionnaire was distributed to patients before and after desensitization to determine pre‐desensitization and post‐desensitization symptoms associated with alcohol ingestion. Results: Forty‐five patients were enrolled and 37 patients completed the study. The most common pre‐desensitization symptoms were nasal congestion (95.6%), rhinorrhea (46.7%), and wheezing (40%). Improvement in the ability to tolerate alcohol was noted in 86.5% of participants (95% confidence interval [CI], 75.5% to 97.5%) and 70.3% of participants (95% CI, 55.5% to 85.0%) described desensitization to be “very helpful” or “extremely helpful” for their ability to tolerate alcohol. Conclusion: The majority of patients with AERD who experience respiratory symptoms with alcohol consumption describe improvement in this domain following aspirin desensitization. [ABSTRACT FROM AUTHOR]

Background Nitric oxide (NO) is an important antibacterial defense molecule produced by upper airway (sinonasal) epithelial cells. We previously showed that a bitter taste receptor expressed in airway epithelium detects quorum-sensing molecules secreted by Gram-negative bacteria and subsequently triggers bactericidal NO production. We hypothesized that the upper airway epithelium may also be able to detect the Gram-positive aerobe Staphylococcus aureus and mount an NO response. Methods Human sinonasal air-liquid interface (ALI) cultures were treated with methicillin-resistant S. aureus (MRSA)-conditioned medium (CM), and NO production was measured using fluorescence imaging. Inhibitors of bitter taste receptor signaling were used to pharmacologically determine if this pathway was involved in the production of NO. Results A low-molecular-weight, heat, and protease-stabile product found in MRSA CM induced differential, NO synthase (NOS)-mediated NO production. This response varied markedly between individual patients. The MRSA-stimulated NO production was not dependent on 2 important components of bitter taste signaling: phospholipase C isoform β-2 or the transient receptor potential melastatin isoform 5 (TRPM5) ion channel. Conclusion This study shows that a S. aureus product elicits an NO-mediated innate defense response in human upper airway epithelium. The active bacterial product is likely a small, nonpeptide molecule that triggers a pathway independent of bitter taste receptors. Patient variation in the NO response to MRSA product(s), potentially due to genetic differences, might play a role in pathophysiology of Gram-positive upper respiratory infections and/or pathogenesis of chronic rhinosinusitis. [ABSTRACT FROM AUTHOR]

Background Despite their widespread use, antibiotics have not been shown to improve chronic rhinosinusitis (CRS) outcomes. We aimed to determine whether culture-inappropriate postoperative antibiotic therapy was associated with less quality-of-life (QOL) improvement following functional endoscopic sinus surgery (FESS). Methods This retrospective cohort study recruited 376 adult CRS patients undergoing FESS between October 1, 2007 to December 31, 2011. Patient demographics, comorbidities and medications were collected at baseline. Trimethoprim-sulfamethoxazole and clindamycin were administered for 2 weeks postoperatively. The antibiotic appropriateness was determined based on bacterial resistance profile of organisms identified during intraoperative culture. The QOL outcome was defined as change of 22-item Sinonasal Outcome Test scores from preoperative visit to 1-month, 3-month, and 6-month post-FESS. Clinically significant difference was defined as at least 0.5 standard deviations (SD) of baseline QOL score in the reference group. Mixed-effects regression models were performed. Results Seven percent of patients (n = 27) had culture-inappropriate antibiotic therapy, and additional 5% (n = 19) had culture-specific antibiotic adjustment. Compared to patients with culture-appropriate antibiotics, patients with culture-inappropriate antibiotics had significantly less improvement of QOL from baseline to postoperative 1-month and 3-month follow-up where the difference became clinically significant; patients with antibiotic adjustment had more QOL improvement from baseline to 1-month follow-up, but their QOL worsened at 3-month follow-up, and these changes were not clinically significant. However, all effects washed out at 6-month follow-up with no significant differences. Conclusion Culture-inappropriate postoperative antibiotic therapy decreased short-term QOL improvement to a clinically meaningful level after FESS. Culture guided selection of antibiotics may improve short-term FESS outcome. [ABSTRACT FROM AUTHOR]