Ultrasensitive pheromone detection by mammalian vomeronasal neurons

The vomeronasal organ (VNO) is a chemoreceptive organ that is thought to transduce pheromones into electrical responses that regulate sexual, hormonal and reproductive function in mammals. The characteristics of pheromone signal detection by vomeronasal neurons remain unclear. Here we use a mouse VNO slice preparation to show that six putative pheromones evoke excitatory responses in single vomeronasal neurons, leading to action potential generation and elevated calcium entry. The detection threshold for some of these chemicals is remarkably low, near 10(-11) M, placing these neurons among the most sensitive chemodetectors in mammals. Using confocal calcium imaging, we map the epithelial representation of the pheromones to show that each of the ligands activates a unique, nonoverlapping subset of vomeronasal neurons located in apical zones of the epithelium. These neurons show highly selective tuning properties and their tuning curves do not broaden with increasing concentrations of ligand, unlike those of receptor neurons in the main olfactory epithelium. These findings provide a basis for understanding chemical signals that regulate mammalian communication and sexual behaviour.

Elevated ACE-2 expression in the olfactory neuroepithelium: implications for anosmia and upper respiratory SARS-CoV-2 entry and replication

The ongoing outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a major threat to global health [1]. The mechanism of cellular entry by SARS-CoV-2 is through binding to angiotensin-converting enzyme 2 (ACE-2) [2, 3], a metalloproteinase ectoenzyme that primarily functions in the regulation of angiotensin II, but also has non-catalytic roles such as intestinal neutral amino acid transport. The level of ACE-2 protein and its subcellular localisation in the respiratory tract may be a key determinant of susceptibility to infection, symptoms and outcomes in COVID-19. In humans, ACE-2 protein is broadly expressed in the lung, kidney and small intestine [4]. Pathological analysis of COVID-19 post mortem samples shows substantial damage in the lung [5], suggesting that the airway is the principal entry and target of SARS-CoV-2. However, analysis of multiple single cell RNA-seq datasets reveal overall low ACE-2 RNA transcription in nasal airway epithelium, with further reduced expression in lower airway club cells and rare expression in alveolar epithelial cells [6]. This pattern of ACE-2 expression provides evidence that the upper, rather than the lower, airway is the initial site of SARS-CoV-2 infection.

ACE2 protein is expressed at high levels in the human olfactory epithelium relative to upper airway epithelial cells. This may explain COVID-19-associated olfactory dysfunction, and suggests a SARS-CoV-2 reservoir site and potential intranasal therapy.https://bit.ly/3hxT0qm

Chronic Cough Due to Gastroesophageal Reflux in Adults: CHEST Guideline and Expert Panel Report

BACKGROUND

We updated the 2006 ACCP clinical practice guidelines for management of reflux-cough syndrome.

METHODS

Two population, intervention, comparison, outcome (PICO) questions were addressed by systematic review: (1) Can therapy for gastroesophageal reflux improve or eliminate cough in adults with chronic and persistently troublesome cough? and (2) Are there minimal clinical criteria to guide practice in determining that chronic cough is likely to respond to therapy for gastroesophageal reflux?

RESULTS

We found no high-quality studies pertinent to either question. From available randomized controlled trials (RCTs) addressing question #1, we concluded that (1) there was a strong placebo effect for cough improvement; (2) studies including diet modification and weight loss had better cough outcomes; (3) although lifestyle modifications and weight reduction may be beneficial in suspected reflux-cough syndrome, proton pump inhibitors (PPIs) demonstrated no benefit when used in isolation; and (4) because of potential carryover effect, crossover studies using PPIs should be avoided. For question #2, we concluded from the available observational trials that (1) an algorithmic approach to management resolved chronic cough in 82% to 100% of instances; (2) cough variant asthma and upper airway cough syndrome (UACS) (previously referred to as postnasal drip syndrome) from rhinosinus conditions were the most commonly reported causes; and (3) the reported prevalence of reflux-cough syndrome varied widely.

CONCLUSIONS

The panelists (1) endorsed the use of a diagnostic/therapeutic algorithm addressing causes of common cough, including symptomatic reflux; (2) advised that although lifestyle modifications and weight reduction may be beneficial in suspected reflux-cough syndrome, PPIs demonstrated no benefit when used in isolation; and (3) suggested that physiological testing be reserved for refractory patients being considered for antireflux surgery or for those in whom there is strong clinical suspicion warranting diagnostic testing.

Chronic Inflammation Directs an Olfactory Stem Cell Functional Switch from Neuroregeneration to Immune Defense

Although olfactory mucosa possesses long-lived horizontal basal stem cells (HBCs) and remarkable regenerative capacity, the function of human olfactory neuroepithelium is significantly impaired in chronic inflammatory rhinosinusitis. Here, we show that, while inflammation initially damages olfactory neurons and activates HBC-mediated regeneration, continued inflammation locks HBCs in an undifferentiated state. Global gene expression in mouse HBCs reveals broad upregulation of NF-κB-regulated cytokines and chemokines including CCL19, CCL20, and CXCL10, accompanied by enhancement of "stemness"-related transcription factors. Loss-of-function studies identify an NF-κB-dependent role of HBCs in amplifying inflammatory signaling, contributing to macrophage and T cell local proliferation. Chronically activated HBCs signal macrophages to maintain immune defense and prevent Treg development. In diseased human olfactory tissue, activated HBCs in a P63⁺ undifferentiated state similarly contribute to inflammation through chemokine production. These observations establish a mechanism of chronic rhinosinusitis-associated olfactory loss, caused by a functional switch of neuroepithelial stem cells from regeneration to immune defense.

Constitutive and inducible expression of b7 family of ligands by human airway epithelial cells

Activated T cells have been implicated in chronic rhinosinusitis (CRS) and asthma and physically interact with epithelial cells in the airways. We now report that human airway epithelial cells display significant constitutive cell-surface expression of costimulatory ligands, B7-H1, B7-H2, B7-H3, and B7-DC. Expression of B7-H1 and B7-DC was selectively induced by stimulation of either BEAS2B or primary nasal epithelial cells (PNEC) with interferon (IFN)-gamma (100 ng/ml). The combination of IFN-gamma and tumor necrosis factor-alpha (100 ng/ml) selectively induced expression better than IFN-gamma alone. Fluticasone treatment (10(-7) M) reduced the baseline expression and inhibited the induction of B7-H1 and B7-DC in BEAS2B cells. In vitro exposure of PNEC to IFN-gamma also resulted in selective induction of B7-H1 and B7-DC. Monoclonal antibody blockade of B7-H1 or B7-DC enhanced IFN-gamma expression by purified T cells in co-culture experiments, suggesting that these two B7 homologs inhibit T cell responses at the mucosal surface. Immunohistochemical staining of human sinonasal surgical tissue confirmed the presence of B7-H1, B7-H2, and B7-H3 in the epithelial cell layer, especially in samples from patients diagnosed with Samter's Triad, a severe form of CRS. Real-time PCR analysis of sinonasal tissue revealed elevated levels of B7-H1 and B7-DC in CRS compared with controls. These results demonstrate that epithelial cells express functional B7 costimulatory molecules and that expression of selected B7 family members is inducible in vitro and in vivo. Epithelial B7 homologs could play a role in regulation of lymphocytic activity at mucosal surfaces.

Treatment-recalcitrant chronic rhinosinusitis with polyps is associated with altered epithelial cell expression of interleukin-33

BACKGROUND

Abnormalities in host mucosal immunity exist in chronic rhinosinusitis with nasal polyps (CRSwNPs), but it is unclear whether this is a cause or an effect of the eosinophilic inflammation and frequent microbial colonization that characterizes the disease. Sinonasal epithelial cells (SNECs) are critical participants in healthy antimicrobial innate immune defense. They also can promote Th2 inflammation with various mediators, including interleukin (IL)-33, which induces T helper cells to produce Th2 cytokines.

METHODS

CRSwNP SNECs were obtained during sinus surgery and stored. Patients were subsequently classified as either treatment responsive or treatment recalcitrant, based on long-term outcomes of medical and surgical therapy. Epithelial cells from these patients were grown in air-liquid interface (ALI) culture and treated with IL-13, as well as the bacteria-associated molecule, CpG. Expression of IL-33 mRNA was determined by real-time polymerase chain reaction.

RESULTS

Recalcitrant CRSwNP epithelial cells had increased baseline expression of IL-33 compared with responsive CRSwNPs, which was further increased by 24-hour exposure to CpG. Treatment-responsive epithelial cells were not induced by CpG to express IL-33. Prolonged treatment with IL-13 during differentiation at the ALI diminished the baseline expression of IL-33 and prevented the subsequent induction of IL-33 by CpG.

CONCLUSION

Mucosal innate immunity likely plays an important role in CRSwNP pathogenesis. A definitive link between infectious triggers and the development of Th2 inflammation has been elusive. We have found constitutive IL-33 expression by SNECs in recalcitrant CRSwNPs, which can be further induced by a bacteria-associated molecular pattern. Dysregulated epithelial cell immune interactions between host and environment may contribute to Th2 inflammation in CRSwNPs.

COVID-19 Vaccines May Not Prevent Nasal SARS-CoV-2 Infection and Asymptomatic Transmission

Current COVID-19 vaccine candidates are administered by injection and designed to produce an IgG response, preventing viremia and the COVID-19 syndrome. However, systemic respiratory vaccines generally provide limited protection against viral replication and shedding within the airway, as this requires a local mucosal secretory IgA response. Indeed, preclinical studies of adenovirus and mRNA candidate vaccines demonstrated persistent virus in nasal swabs despite preventing COVID-19. This suggests that systemically vaccinated patients, while asymptomatic, may still be become infected and transmit live virus from the upper airway. COVID-19 is known to spread through respiratory droplets and aerosols. Furthermore, significant evidence has shown that many clinic and surgical endonasal procedures are aerosol generating. Until further knowledge is acquired regarding mucosal immunity following systemic vaccination, otolaryngology providers should maintain precautions against viral transmission to protect the proportion of persistently vulnerable patients who exhibit subtotal vaccine efficacy or waning immunity or who defer vaccination.

Altered Expression of Genes Associated with Innate Immunity and Inflammation in Recalcitrant Rhinosinusitis with Polyps

Background

The role of the innate immune system in the pathophysiology of chronic rhinosinusitis (CRS) is poorly understood. In this study, we compared sinonasal expression of toll-like receptors (TLRs), complement components, serum amyloid A, and inflammatory genes (chemokines and cytokines) in control subjects and patients undergoing sinus surgery for CRS.

Methods

Eleven control subjects and 30 subjects with CRS unresponsive to medical management were enrolled prospectively before undergoing endoscopic sinus surgery. Ethmoid mucosal specimens were obtained surgically and processed for RNA extraction. Real-time polymerase chain reaction was used to quantitate the level of expression of messenger RNA (mRNA) for TLR, acute phase proteins, and cytokine genes. Subjects were followed for a minimum of 6 months postoperatively with nasal endoscopy to assess for recurrence of polyps.

Results

mRNA for all target genes was detected in the ethmoid mucosa of both control and CRS subjects. The level of gene expression was normalized to the housekeeping genes 18s RNA and glyceraldehyde-3-phosphate dehydrogenase. As compared with controls, CRS was associated with significantly higher expression of TLR2 and the inflammatory genes macrophage-inflammatory protein a, RANTES, and granulocyte-macrophage colony-stimulating factor. Patients with early recurrence of polyps after surgery had significantly decreased expression of TLR2, 9, and serum amyloid A and increased expression of macrophage-inflammatory protein a compared with surgery-responsive patients.

Conclusion

This study shows the increased levels of expression of TLR2 and a variety of inflammatory genes in sinonasal mucosa of CRS patients compared with controls. Whether these differences play a role in pathogenesis or are merely manifestations of disease activity is worthy of investigation.

Central role of the CNGA4 channel subunit in Ca2+-calmodulin-dependent odor adaptation

Heteromultimeric cyclic nucleotide-gated (CNG) channels play a central role in the transduction of odorant signals and subsequent adaptation. The contributions of individual subunits to native channel function in olfactory receptor neurons remain unclear. Here, we show that the targeted deletion of the mouse CNGA4 gene, which encodes a modulatory CNG subunit, results in a defect in odorant-dependent adaptation. Channels in excised membrane patches from the CNGA4 null mouse exhibited slower Ca2+-calmodulin-mediated channel desensitization. Thus, the CNGA4 subunit accelerates the Ca2+-mediated negative feedback in olfactory signaling and allows rapid adaptation in this sensory system.

Th2 cytokines associated with chronic rhinosinusitis with polyps down-regulate the antimicrobial immune function of human sinonasal epithelial cells

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNPs) is a disorder characterized by persistent eosinophilic Th2 inflammation and frequent sinonasal microbial colonization. It has been postulated that an abnormal mucosal immune response underlies disease pathogenesis. The relationship between Th2 inflammatory cytokines and the innate immune function of sinonasal epithelial cells (SNECs) has not been explored.

METHODS

Human SNECs (HSNECs) isolated from control subjects and patients with CRS were assessed for expression of antimicrobial innate immune genes and proinflammatory cytokine genes by real-time polymerase chain reaction, ELISA, and flow cytometry. A model of the Th2 inflammatory environment was created by exposure of primary HSNEC to the Th2 cytokine interleukin (IL)-4 or IL-13 for 36 hours, with subsequent assessment of innate immune gene expression.

RESULTS

HSNEC obtained from CRSwNP patients displayed decreased expression of multiple antimicrobial innate immune markers, including toll-like receptor 9, human beta-defensin 2, and surfactant protein A. Baseline expression of these genes by normal and CRS HSNEC in culture is significantly down-regulated after incubation with IL-4 or IL-13.

CONCLUSION

Expression of multiple innate immune genes by HSNEC is reduced in CRSwNP. One mechanism appears to be a direct effect of the leukocyte-derived Th2 cytokines present in the sinonasal mucosa in CRSwNP. Impaired mucosal innate immunity may contribute to microbial colonization and abnormal immune responses associated with CRSwNP.

Sinonasal epithelial cell expression of toll-like receptor 9 is decreased in chronic rhinosinusitis with polyps

BACKGROUND

Innate immune recognition of pathogens by sinonasal epithelial cells may play an important role in the pathogenesis of chronic rhinosinusitis (CRS). Previous studies have indicated that toll-like receptor (TLR) mRNA is present in sinonasal mucosa, and levels of TLR9 expression are decreased in recalcitrant CRS with nasal polyps (CRSwNP). However, the cellular source and function of TLR9 in the sinonasal epithelium is not known. In this study, primary epithelial cell cultures were analyzed from control subjects and CRSwNP patients to determine the presence and function of TLR9 protein.

METHODS

Primary epithelial cell cultures were established from 5 controls and 10 CRSwNP patients undergoing sinus surgery. Flow cytometry was used to confirm purity of epithelial cells and to assess expression of TLR9 protein. Epithelial cells were stimulated with TLR9 agonist, and mRNA was analyzed by real-time PCR for expression of human beta-defensin (HBD) 2 and interleukin (IL)-8.

RESULTS

Flow cytometry showed TLR9 protein in 100% of epithelial cells from controls and CRSwNP patients. The level of expression was 50% lower in CRS patients than in controls. Stimulation of epithelial cells with TLR9 agonist produced a 1.5- to 9-fold increase in HBD-2 and IL-8 mRNA expression.

CONCLUSION

Functional TLR9 protein is expressed by normal and diseased sinonasal epithelial cells. The level of TLR9 expression is decreased in CRSwNP patients, consistent with the previous finding of decreased TLR9 mRNA in whole sinonasal tissue. These findings suggest that impaired innate immune responses to pathogens via TLR9 on sinonasal epithelial cells may represent a critical mechanism in chronic inflammatory sinus disease.

Chronic rhinosinusitis as a multifactorial inflammatory disorder

Chronic rhinosinusitis (CRS) is a prevalent health condition characterized by sinonasal mucosal inflammation lasting at least 12 weeks. Heterogeneous in clinical presentation, histopathology, and therapeutic response, CRS represents a spectrum of disease entities with variable pathophysiology. Increased knowledge of cellular and molecular derangements in CRS suggests potential etiologies and targets for therapy. Microbial elements including fungi, staphylococcal enterotoxin, and biofilms have been implicated as inflammatory stimuli, along with airborne irritants and allergens. Defects in innate immunity have gained increased attention as contributors to the chronic inflammatory state. A combination of host susceptibility and environmental exposure is widely believed to underlie CRS, although direct evidence is lacking. Presently, without precise disease definitions and identifiable universal triggers, CRS pathogenesis is broadly described as multifactorial. Current research is beginning to unravel complex and diverse effects of chronic inflammation on sinonasal mucosal homeostasis, but dysfunctional pathways of inflammatory regulation and resolution require further elucidation.

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titres of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titres in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches.

Innate immunity of the sinonasal cavity and its role in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is one of the most common health problems in the United States. Medical therapy and surgery are successful in treating the majority of patients with sinusitis; however, CRS patients recalcitrant to traditional therapy are increasingly prevalent. Although traditionally this illness could be explained by sinus ostial obstruction and persistent bacterial infection, the rhinologic literature over the years has suggested a significant underlying inflammatory component. Adaptive immune components, including lymphocytes and their associated cytokines, have been the subject of most research in chronic nasal inflammation. A recent appreciation of the importance of the innate immune system is leading to new areas of investigation regarding the pathogenesis of CRS. This review will outline our current knowledge of sinonasal innate immunity, the role of innate immunity in the pathogenesis of CRS, and potential therapeutic targets in the innate immune system.

The cigarette smoke component acrolein inhibits expression of the innate immune components IL-8 and human beta-defensin 2 by sinonasal epithelial cells

BACKGROUND

Tobacco use is associated with poorer outcomes of medical and surgical therapy for chronic rhinosinusitis (CRS), although the underlying mechanism is unknown. Acrolein (AC) is a major component of cigarette smoke that has been shown to suppress innate immune gene expression by human bronchial epithelial cells and murine macrophages. In this study, we explore whether exposure of human sinonasal epithelial cells (HSNECs) to AC similarly reduces their innate immune gene expression.

METHODS

Primary HSNECs from CRS patients were grown in culture, either differentiated or submerged. HSNECs were treated for 30 minutes with 0-50 microM of AC and were subsequently analyzed by real-time polymerase chain reaction and ELISA to determine IL-8 and human beta-defensin (HBD) 2 expression. Total glutathione was measured to see the oxidative stress within the treatment range.

RESULTS

In primary HSNEC, IL-8 mRNA levels decreased dose dependently in the range of 10-50 microM of AC with an eightfold decrease at 50 microM. In addition, a 125-fold decrease at 50 microM for IL-8 protein was observed. HBD-2 mRNA decreased twofold and HBD-2 protein decreased fourfold at 50 microM of AC in primary HSNEC. However, differentiated HSNEC showed a marginal decrease in a dose-dependent manner for both IL-8 and HBD-2 within the range of 10-50 microM of AC. There was no oxidative stress observed over this range of AC concentration.

CONCLUSION

The tobacco smoke component AC has the capacity to suppress the inflammatory and innate immune function of sinonasal epithelial cells. Whether this effect contributes to the negative clinical impact of smoking on CRS outcomes merits additional investigation.

Innate immunity of the sinonasal cavity: expression of messenger RNA for complement cascade components and toll-like receptors

OBJECTIVE

To study the expression of important elements of the innate immune responses in human sinonasal tissue to elucidate its potential role in mucosal inflammation.

DESIGN

We studied human sinonasal tissue from patients with chronic rhinosinusitis and an immortalized epithelial cell line to detect the expression of innate immune effectors and the responses of these cells to stimulation with compounds associated with pathogenic organisms.

PATIENTS

Nine individuals undergoing endoscopic sinus surgery for chronic rhinosinusitis.

MAIN OUTCOME MEASURES

Expression of complement components and toll-like receptors.

RESULTS

We found detectable levels of messenger RNA for all toll-like receptors in human sinonasal tissue and in the BEAS-2B epithelial cell line. Expression of several components of the alternate pathway of complement (factors B, H, and I and properdin) was constitutively present in unstimulated BEAS-2B cells and was readily detectable in human sinonasal tissue. Stimulation of BEAS-2B cells with the toll-like receptor 3 ligand double-stranded RNA resulted in increased expression of messenger RNA for factors B and H but not for properdin or factor I.

CONCLUSIONS

Toll-like receptors and the alternate pathway of complement are important components of innate immunity that are expressed in human sinonasal epithelium in vivo and in cultured airway epithelial cells in vitro. The expression of some of these components can be significantly induced by stimulation via toll-like receptors, and epithelial expression of components of innate immunity may play a role in inflammation in chronic rhinosinusitis.

Estrogenic compounds reduce influenza A virus replication in primary human nasal epithelial cells derived from female, but not male, donors

Influenza causes an acute infection characterized by virus replication in respiratory epithelial cells. The severity of influenza and other respiratory diseases changes over the life course and during pregnancy in women, suggesting that sex steroid hormones, such as estrogens, may be involved. Using primary, differentiated human nasal epithelial cell (hNEC) cultures from adult male and female donors, we exposed cultures to the endogenous 17β-estradiol (E2) or select estrogen receptor modulators (SERMs) and then infected cultures with a seasonal influenza A virus (IAV) to determine whether estrogenic signaling could affect the outcome of IAV infection and whether these effects were sex dependent. Estradiol, raloxifene, and bisphenol A decreased IAV titers in hNECs from female, but not male, donors. The estrogenic decrease in viral titer was dependent on the genomic estrogen receptor-2 (ESR2) as neither genomic ESR1 nor nongenomic GPR30 was expressed in hNEC cultures and addition of the genomic ER antagonist ICI 182,780 reversed the antiviral effects of E2. Treatment of hNECs with E2 had no effect on interferon or chemokine secretion but significantly downregulated cell metabolic processes, including genes that encode for zinc finger proteins, many of which contain estrogen response elements in their promoters. These data provide novel insights into the cellular and molecular mechanisms of how natural and synthetic estrogens impact IAV infection in respiratory epithelial cells derived from humans.

Medical therapy reduces microbiota diversity and evenness in surgically recalcitrant chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a highly prevalent and heterogeneous condition frequently treated with antibiotics and corticosteroid therapy. However, the effect of medical therapy on sinus microbiota remains unknown.

METHODS

We enrolled CRS patients (n = 6) with patent maxillary antrostomies and active mucosal inflammation, who had not received antibiotics or corticosteroids in the previous 8 weeks. A pretreatment and posttreatment maxillary sinus swab was collected, from which DNA was extracted, pyrosequenced, and analyzed using a naïve Bayesian classifier and ecological analyses.

RESULTS

Four patients showed significant improvement in endoscopic appearance. The shifts in microbiota in response to therapy were highly individualized. There was no single common microbiota profile among patients with similar clinical outcomes, but overall there was significant decrease in microbiota diversity (t(5) = 2.05, p = 0.10) and evenness (t(5) = 2.28, p = 0.07) after treatment.

CONCLUSION

Our findings strongly correlate with earlier studies that examined the impact of antibiotics on human microbiota. We observed that posttreatment, patients frequently became colonized by taxa that are less susceptible to the prescribed antibiotics. Our findings highlight the challenge in seeking generalizable diagnostic and therapeutic options in CRS, particularly regarding microbiological response and outcomes.

Serum Amyloid A, Properdin, Complement 3, and Toll-Like Receptors are Expressed Locally in Human Sinonasal Tissue

Background

There is a growing appreciation of the role that nasal mucosa plays in innate immunity. In this study, the expression of pattern recognition receptors known as toll-like receptors (TLRs) and the effector molecules complement factor 3 (C3), properdin, and serum amyloid A (SAA) were examined in human sinonasal mucosa obtained from control subjects and patients with chronic rhinosinusitis (CRS).

Methods

Sinonasal mucosal specimens were obtained from 20 patients with CRS and 5 control subjects. Messenger RNA (mRNA) was isolated and tested using Taqman real-time polymerase chain reaction with primer and probe sets for C3, complement factor P, and SAA. Standard polymerase chain reaction was performed for the 10 known TLRs. Immunohistochemistry was performed on the microscopic sections using antibodies against C3

Results

Analysis of the sinonasal sample mRNA revealed expression of all 10 TLRs in both CRS samples and in control specimens. Expression of the three effector proteins was detected also, with the levels of mRNA for C3 generally greater than SAA and properdin in CRS patients. No significant differences were found in TLR or innate immune protein expression in normal controls. Immunohistochemical analysis of sinonasal mucosal specimens established C3 staining ranging from 20 to 85% of the epithelium present.

Conclusion

These studies indicate that sinonasal mucosa expresses genes involved in innate immunity including the TLRs and proteins involved in complement activation. We hypothesize that local production of complement and acute phase proteins by airway epithelium on stimulation of innate immune receptors may play an important role in host defense in the airway and, potentially, in the pathogenesis of CRS.

Development and pilot-testing of a feasible, reliable, and valid operative competency assessment tool for endoscopic sinus surgery

BACKGROUND

Otolaryngology residency programs are required by the Accreditation Council for Graduate Medical Education to evaluate residents' operative competency. Many such tools based on the model of objective structured assessment of technical skills (OSATSs) have been developed in other surgical specialties, but no such instruments exist for otolaryngologic procedures except for tonsillectomy. Endoscopic sinus surgery (ESS) is among the most common rhinologic procedure and lends itself to objective evaluation of operative competency. The purpose of this study was to develop and test a new tool for ESS, focusing on feasibility, content and construct validity, and interrater agreement that can be used for such assessment in the operating room and the cadaver dissection course.

METHODS

Faculty input via the modified Delphi technique helped develop the content of a new OSATS-based instrument. The instrument underwent serial improvements based on 3 years of endoscopic sinus surgery (ESS) cadaver courses. All evaluations were used to calculate construct validity while paired observations were used to determine interrater agreement. Regional and national faculty input was incorporated for increasing generalizability. Internal consistency was calculated using Cronbach's alpha.

RESULTS

A total of 51 assessments were completed for 28 residents who were evaluated by 15 faculty members as they performed ESS on cadavers over a period of 3 years. A high degree of internal consistency (0.99) and feasibility was noted for the instrument, which took 7 minutes to complete. The interrater agreement improved with focused faculty development for the 3rd year of the course.

CONCLUSION

Our results and experience suggest that a feasible, reliable, and valid instrument for objective evaluation of operative competency can be developed for ESS. Further experience at other otolaryngology programs and efforts focused on faculty development will be needed to enhance faculty buy-in. The instrument can be used for formative and summative feedback as well as for identifying residents needing remediation.

Somatic Cough Syndrome (Previously Referred to as Psychogenic Cough) and Tic Cough (Previously Referred to as Habit Cough) in Adults and Children: CHEST Guideline and Expert Panel Report

BACKGROUND

We conducted a systematic review on the management of psychogenic cough, habit cough, and tic cough to update the recommendations and suggestions of the 2006 guideline on this topic.

METHODS

We followed the American College of Chest Physicians (CHEST) methodologic guidelines and the Grading of Recommendations, Assessment, Development, and Evaluation framework. The Expert Cough Panel based their recommendations on data from the systematic review, patients' values and preferences, and the clinical context. Final grading was reached by consensus according to Delphi methodology.

RESULTS

The results of the systematic review revealed only low-quality evidence to support how to define or diagnose psychogenic or habit cough with no validated diagnostic criteria. With respect to treatment, low-quality evidence allowed the committee to only suggest therapy for children believed to have psychogenic cough. Such therapy might consist of nonpharmacologic trials of hypnosis or suggestion therapy, or combinations of reassurance, counseling, and referral to a psychologist, psychotherapy, and appropriate psychotropic medications. Based on multiple resources and contemporary psychologic, psychiatric, and neurologic criteria (Diagnostic and Statistical Manual of Mental Disorders, 5th edition and tic disorder guidelines), the committee suggests that the terms psychogenic and habit cough are out of date and inaccurate.

CONCLUSIONS

Compared with the 2006 CHEST Cough Guidelines, the major change in suggestions is that the terms psychogenic and habit cough be abandoned in favor of somatic cough syndrome and tic cough, respectively, even though the evidence to do so at this time is of low quality.

Use of computed tomography in the assessment of mandibular invasion in carcinoma of the retromolar trigone

Carcinomas originating in the retromolar trigone (RMT) are uncommon and characterized by early spread. Determination of mandibular invasion is significant for planning therapy and determining prognosis. For oral cavity cancers in general, CT is reasonably accurate in assessing bone invasion. However, there is a paucity of information specifically addressing the value of CT in the RMT. In this study, the records of patients with biopsy-proven RMT carcinomas treated between 1984 and 1998 were reviewed with attention to preoperative CT scans and histopathologic findings during surgery. Half of the patients who were treated with primary resection had mandibular invasion. Bone invasion was not identified radiographically in 27% of patients with preoperative CT scans. The sensitivity of CT for bone involvement in RMT cancers was 50%, with a negative predictive value of 61.1%. The positive predictive value was 91.1%. These findings suggest that CT is a useful, but potentially inaccurate, predictor of bone invasion in the RMT.

Tumor necrosis factor alpha inhibits olfactory regeneration in a transgenic model of chronic rhinosinusitis-associated olfactory loss

BACKGROUND

Olfactory loss is a debilitating symptom of chronic rhinosinusitis (CRS). Although olfactory sensory neurons (OSNs) are normally regenerated constantly in the olfactory epithelium (OE), a transgenic model of CRS-associated olfactory loss (inducible olfactory inflammation [IOI] mouse) shows that inflammation causes widespread OSN loss without progenitor cell proliferation. In this study, we further examine whether the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) inhibits olfactory regeneration.

METHODS

IOI mice underwent either unilateral bulbectomy or sham surgery and then were induced to express TNF-alpha in the OE for 1 week. After death, the mice were assessed histologically and with bromodeoxyuridine staining to determine the effect of TNF-alpha on olfactory regeneration.

RESULTS

In the absence of TNF-alpha, bulbectomy was associated with death of OSNs, followed by robust proliferation of neural progenitors and regrowth of the OE. At 12 days postbulbectomy, OE thickness on the operated side had recovered to >80% of the unoperated side. In mice in which TNF-alpha expression was induced, significantly reduced proliferation was observed, associated with failure of normal reconstitution of OE thickness.

CONCLUSION

The mechanism of olfactory dysfunction in CRS remains incompletely understood. Previous studies with a transgenic mouse model suggested that inflammation inhibits progenitor cell proliferation and olfactory regeneration. Here, the role of the CRS-associated cytokine TNF-alpha was investigated using surgical ablation of the olfactory bulb to stimulate synchronous OSN turnover. We find that TNF-alpha expression prevents normal OE recovery, supporting the role of suppressed olfactory regeneration in the pathophysiology of CRS-associated olfactory loss.

The role of TNF-α in inflammatory olfactory loss

BACKGROUND

Despite the significant health impact of olfactory loss in chronic rhinosinusitis (CRS), the underlying pathophysiology is incompletely understood. A transgenic mouse model of olfactory inflammation induced by tumor necrosis factor-alpha (TNF-α) has provided new insights into the cellular and molecular basis of inflammatory olfactory loss. Here, we utilize systemic corticosteroids to suppress downstream cytokine expression, in order to study the direct role of TNF-α in CRS-associated olfactory dysfunction.

METHODS

Transgenic mice were induced to express TNF-α in the olfactory epithelium for 6 weeks. In a subset of mice, 1 mg/kg prednisolone was administered concurrently to inhibit downstream inflammatory responses. The olfactory epithelium (OE) was analyzed by histology and electro-olfactogram (EOG) recordings.

RESULTS

Treatment with prednisolone successfully prevented inflammatory infiltration over significant regions of the OE. In areas where significant subepithelial inflammation was present, a corresponding loss of olfactory neurons was observed. In contrast, areas without major inflammatory changes had normal olfactory neuron layers, despite chronic local expression of TNF-α. Prednisolone partially reversed the complete loss of olfaction in the mouse model, preserving odorant responses that were significantly diminished compared to controls, but not absent.

CONCLUSIONS

The addition of prednisolone to the transgenic model of olfactory inflammation isolates the direct effects of induced TNF-α expression on the OE. The finding that prednisolone treatment prevents neuronal loss in some regions of the OE suggests that TNF-α does not directly cause neuronal apoptosis--rather, that subepithelial inflammation or other downstream mediators may be responsible. At the same time, EOG results imply that TNF-α directly causes physiologic dysfunction of olfactory neurons, independent of the inflammatory state. An understanding of the role of TNF-α and other inflammatory cytokines may suggest novel therapeutic strategies for CRS-associated olfactory loss.

Blocking adenylyl cyclase inhibits olfactory generator currents induced by "IP(3)-odors"

Vertebrate olfactory receptor neurons (ORNs) transduce odor stimuli into electrical signals by means of an adenylyl cyclase/cAMP second messenger cascade, but it remains widely debated whether this cAMP cascade mediates transduction for all odorants or only certain odor classes. To address this problem, we have analyzed the generator currents induced by odors that failed to produce cAMP in previous biochemical assays but instead produced IP(3) ("IP(3)-odors"). We show that in single salamander ORNs, sensory responses to "cAMP-odors" and IP(3)-odors are not mutually exclusive but coexist in the same cells. The currents induced by IP(3)-odors exhibit identical biophysical properties as those induced by cAMP odors or direct activation of the cAMP cascade. By disrupting adenylyl cyclase to block cAMP formation using two potent antagonists of adenylyl cyclase, SQ22536 and MDL12330A, we show that this molecular step is necessary for the transduction of both odor classes. To assess whether these results are also applicable to mammals, we examine the electrophysiological responses to IP(3)-odors in intact mouse main olfactory epithelium (MOE) by recording field potentials. The results show that inhibition of adenylyl cyclase prevents EOG responses to both odor classes in mouse MOE, even when "hot spots" with heightened sensitivity to IP(3)-odors are examined.