Consensus criteria for chronic rhinosinusitis disease control: an international Delphi Study.

BACKGROUND: Chronic rhinosinusitis (CRS) disease control is a global metric of disease status for CRS. While there is broad acceptance that it is an important treatment goal, there has been inconsistency in the criteria used to define CRS control. The objective of this study was to identify and develop consensus around essential criteria for assessment of CRS disease control. METHODS: Modified Delphi methodology consisting of three rounds to review a list of 24 possible CRS control criteria developed by a 12-person steering committee. The core authorship of the multidisciplinary EPOS 2020 guidelines was invited to participate. RESULTS: Thirty-two individuals accepted the invitation to participate and there was no dropout of participants throughout the entire study (3 rounds). Consensus essential criteria for assessment of CRS control were: overall symptom severity, need for CRS-related systemic corticosteroids in the prior 6 months, severity of nasal obstruction, and patient-reported CRS control. Near-consensus items were: nasal endoscopy findings, severity of smell loss, overall quality of life, impairment of normal activities and severity of nasal discharge. Participants’ comments provided insights into caveats of, and disagreements related to, near-consensus items. CONCLUSIONS: Overall symptom severity, use of CRS-related systemic corticosteroids, severity of nasal obstruction, and patient-reported CRS control are widely agreed upon essential criteria for assessment of CRS disease control. Consideration of near-consensus items to assess CRS control should be implemented with their intrinsic caveats in mind. These identified consensus CRS control criteria, together with evidence-based support, will provide a foundation upon which CRS control criteria with wide-spread acceptance can be developed.

The EUFOREA pocket guide for chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is known to affect around 5 % of the total population, with major impact on the quality of life of those severely affected (1). Despite a substantial burden on individuals, society and health economies, CRS often remains underdiagnosed, under-estimated and under-treated (2). International guidelines like the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) (3) and the International Consensus statement on Allergy and Rhinology: Rhinosinusitis 2021 (ICAR) (4) offer physicians insight into the recommended treatment options for CRS, with an overview of effective strategies and guidance of diagnosis and care throughout the disease journey of CRS.

Short-chain fatty acids induce tissue plasminogen activator in airway epithelial cells via GPR41&43.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease generally divided based on the presence or absence of nasal polyps (NPs). One of the features of NPs is excessive fibrin deposition, which is associated with down-regulation of tissue plasminogen activator (t-PA) in NPs. As t-PA is expressed in epithelial cells, and epithelium is readily accessible to topical therapies, identifying compounds that can mediate the induction of t-PA would be a potential new strategy for the treatment of NPs. OBJECTIVE: The objective of this study was to determine whether short-chain fatty acids (SCFAs) can induce t-PA in airway epithelial cells via their known receptors GPR41 and GPR43. METHODS: We performed immunohistochemistry (IHC) to determine whether receptors for SCFAs, known as G protein-coupled receptor 41/free fatty acid receptor 3 (GPR41/FFAR3) and GPR43/FFAR2, are expressed in nasal tissue. Primary normal human bronchial epithelial (NHBE) cells were stimulated with different concentrations of SCFAs to test induction of t-PA, which was analysed by expression of mRNA and protein. Mediation of responses by SCFA receptors was evaluated by specific receptor gene silencing with siRNA. RESULTS: Immunohistochemistry study revealed that airway epithelial cells expressed GPR41 and GPR43. Acetic acid, propionic acid, butyric acid and valeric acid significantly induced t-PA expression from two- to tenfolds. The strongest inducer of t-PA from NHBE cells was propionic acid; cells stimulated with propionic acid released t-PA into the supernatant in its active form. Gene silencing of GPR41 and GPR43 revealed that induction of t-PA by SCFAs was dependent upon both GPR41 and GPR43. CONCLUSIONS AND CLINICAL RELEVANCE: Short-chain fatty acids were shown to induce airway epithelial cell expression of t-PA via GPR41 and GPR43. Topical delivery of potent compounds that activate these receptors may have value by reducing fibrin deposition and shrinking nasal polyp growth.

Prevalence, severity, and risk factors for acute exacerbations of nasal and sinus symptoms by chronic rhinosinusitis status.

BACKGROUND: Nasal and sinus symptoms (NSS) are common to many health conditions, including chronic rhinosinusitis (CRS). Few studies have investigated the occurrence and severity of, and risk factors for, acute exacerbations of NSS (AENSS) by CRS status (current, past, or never met European Position Paper on Rhinosinusitis [EPOS] criteria for CRS). METHODS: Four seasonal questionnaires were mailed to a stratified random sample of Geisinger primary care patients. Logistic regression was used to identify individual characteristics associated with AENSS occurrence and severity by CRS status (current long-term, current recent, past, never) using EPOS subjective symptoms-only (EPOSS ) CRS criteria. We operationalized 3 AENSS definitions based on prescribed antibiotics or oral corticosteroids, symptoms, and symptoms with purulence. RESULTS: Baseline and at least 1 follow-up questionnaires were available from 4736 subjects. Self-reported NSS severity with exacerbation was worst in the current long-term CRS group. AENSS was common in all subgroups examined and generally more common among those with current EPOSS CRS. Seasonal prevalence of AENSS differed by AENSS definition and CRS status. Associations of risk factors with AENSS differed by definition, but CRS status, body mass index, asthma, hay fever, sinus surgery history, and winter season consistently predicted AENSS. CONCLUSIONS: In this first longitudinal, population-based study of 3 AENSS definitions, NSS and AENSS were both common, sometimes severe, and differed by EPOSS CRS status. Contrasting associations of risk factors for AENSS by the different definitions suggest a need for a standardized approach to definition of AENSS.

Longitudinal evaluation of clustering of chronic sinonasal and related symptoms using exploratory factor analysis.

BACKGROUND: Sinonasal symptoms are common and can have several underlying causes. When symptoms occur in specified patterns lasting 3 months or more they meet criteria for chronic rhinosinusitis (CRS). Approaches to CRS symptom measurement do not specify how to measure symptoms and treat specified sinonasal symptoms as generally interchangeable, suggesting that such symptoms should cluster on 1 or 2 latent factors. METHODS: We used questionnaire responses to 37 questions on the presence, severity, bother, and frequency of cardinal sinonasal and related symptoms lasting 3 months, from 3535 subjects at 3 time points over 16 months. We completed 5 exploratory factor analyses (EFA) to identify symptom clustering, 1 for each time point and 2 for the differences between adjacent questionnaires. The baseline EFA was used to provide factor scores that were described longitudinally and examined by CRS status. RESULTS: Five EFAs identified the same 5 factors (blockage and discharge, pain and pressure, asthma and cold/flu symptoms, smell loss, and ear and eye [mainly allergy] symptoms), with clustering determined by symptom frequency, severity, and degree of bother. Responses to individual questions showed changes over time but when combined into factor scores showed less longitudinal change. All symptom factor scores were progressively higher from never to past to current CRS status. CONCLUSIONS: Although the current approaches to symptom characterization in CRS imply a single underlying latent construct, our results suggest that there are at least 3 latent constructs relevant to CRS. Further studies are needed to evaluate whether these clusters have identifiable underlying pathobiologies.

Chronic airway inflammation provides a unique environment for B cell activation and antibody production.

BACKGROUND: B cells play many roles in health and disease. However, little is known about the mechanisms that drive B cell responses in the airways, especially in humans. Chronic rhinosinusitis (CRS) is an inflammatory disease of the upper airways that affects 10% of Europeans and Americans. A subset of CRS patients develop nasal polyps (NPs), which are characterized by type 2 inflammation, eosinophils and group 2 innate lymphoid cells (ILC2s). We have reported that NP contain elevated levels of B cells and antibodies, making NP an ideal system for studying B cells in the airways. OBJECTIVE: We sought to determine the mechanisms that drive B cell activation and antibody production during chronic airway inflammation. METHODS: We analysed B cells from NP or tonsil, or after ILC2 coculture, by flow cytometry. Antibody production from tissue was measured using Luminex assays and the frequency of antibody-secreting cells by ELISpot. Formation of B cell clusters was assessed using immunohistochemistry. Expression of genes associated with B cell activation and class switch recombination was measured by qRT-PCR. RESULTS: NP contained significantly elevated frequencies of plasmablasts, especially those that expressed the extrafollicular marker Epstein-Barr virus-induced protein 2 (EBI2), but significantly fewer germinal centre (GC) B cells compared with tonsil. Antibody production and the frequency of antibody-secreting cells were significantly elevated in NP, and there was evidence for local class switch recombination in NP. Finally, ILC2s directly induced EBI2 expression on B cells in vitro. CONCLUSIONS AND CLINICAL RELEVANCE: Our data suggest there is a unique B cell activation environment within NP that is distinct from classic GC-mediated mechanisms. We show for the first time that ILC2s directly induce EBI2 expression on B cells, indicating that ILC2s may play an important role in B cell responses. B cell-targeted therapies may provide new treatment options for CRSwNP.

Nasal and sinus symptoms and chronic rhinosinusitis in a population-based sample.

BACKGROUND: The objective of this study was to describe the first US-based study to use the European Position Paper on Rhinosinusitis (EPOS) criteria to study the prevalence of chronic rhinosinusitis (CRS) in a general-population sample. METHODS: A CRS symptom questionnaire was mailed to 23 700 primary care patients from Geisinger Clinic, a health system serving 45 counties in Pennsylvania. CRS cases were categorized into four unique subgroups based on EPOS symptoms: obstruction and discharge with no smell loss or pain/pressure; smell loss without pain/pressure; facial pain and/or pressure without smell loss; and both smell loss and pain/pressure. All cases were required to have nasal obstruction or discharge. Logistic regression was used to evaluate potential factors associated with CRS subgroups. RESULTS: We found that 11.9% of patients met criteria for CRS. Prevalence peaked at 15.9% between ages 50 and 59 years and then dropped to 6.8% after age 69. The odds of CRS was higher among patients who were white, younger, smokers, had a history of Medical Assistance, and had other diseases. When CRS subgroups were modeled separately, these associations were no longer significant for some CRS subgroups. Comorbid diseases were most strongly associated with CRS cases who reported smell loss and facial pain and/or pressure and had the weakest associations with CRS cases who did not report these symptoms. CONCLUSIONS: CRS is a highly prevalent and heterogeneous condition. Differences in risk factors and health outcomes across symptom subgroups may be indicative of differences in etiology that have implications for disease management.

Elevated presence of myeloid dendritic cells in nasal polyps of patients with chronic rhinosinusitis.

BACKGROUND: Although chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by Th2 inflammation, the mechanism underlying the onset and amplification of this inflammation has not been fully elucidated. Dendritic cells (DCs) are major antigen-presenting cells, central inducers of adaptive immunity and critical regulators of many inflammatory diseases. However, the presence of DCs in CRS, especially in nasal polyps (NPs), has not been extensively studied. OBJECTIVE: The objective of this study was to characterize DC subsets in CRS. METHODS: We used real-time PCR to assess the expression of mRNA for markers of myeloid DCs (mDCs; CD1c), plasmacytoid DCs (pDCs; CD303) and Langerhans cells (LCs; CD1a, CD207) in uncinate tissue (UT) from controls and patients with CRS as well as in NP. We assayed the presence of DCs by immunohistochemistry and flow cytometry. RESULTS: Compared to UT from control subjects (n = 15) and patients with CRS without NP (CRSsNP) (n = 16) and CRSwNP (n = 17), mRNAs for CD1a and CD1c were significantly elevated in NPs (n = 29). In contrast, CD207 mRNA was not elevated in NPs. Immunohistochemistry showed that CD1c(+) cells but not CD303(+) cells were significantly elevated in NPs compared to control subjects or patients with CRSsNP. Flow cytometric analysis showed that CD1a(+) cells in NPs might be a subset of mDC1s and that CD45(+) CD19(-) CD1c(+) CD11c(+) CD141(-) CD303(-) HLA-DR(+) mDC1s and CD45(+) CD19(-) CD11c(+) CD1c(-) CD141(high) HLA-DR(+) mDC2s were significantly elevated in NPs compared to UT from controls and CRSsNP, but CD45(+) CD11c(-) CD303(+) HLA-DR(+) pDCs were only elevated in NPs compared to control UT. CONCLUSION AND CLINICAL RELEVANCE: Myeloid DCs are elevated in CRSwNP, especially in NPs. Myeloid DCs thus may indirectly contribute to the inflammation observed in CRSwNP.

Five-year risk of incident disease following a diagnosis of chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) has a broad range of comorbidities. Due to a lack of longitudinal studies, it is not known whether these comorbidities cause CRS, are promoted by CRS, or share a systemic disease process with CRS. OBJECTIVE: The objective of this study was to determine the risk of incident disease within 5 years after a new diagnosis of CRS with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP). METHODS: We conducted a case-control study nested within the longitudinal cohort of primary care patients in the Geisinger Clinic using electronic health record data. We evaluated incident disease over 5 years in newly diagnosed CRSwNP and CRSsNP cases compared to controls using multivariable Cox regression models. RESULTS: CRSsNP (n = 3612) cases were at greater risk (HR, 95% confidence interval) than controls for incidence of: upper airway diseases, including adenotonsillitis (3.29, 2.41-4.50); lower aerodigestive tract diseases, including asthma (2.69, 2.14-3.38); epithelial conditions, including atopic dermatitis (2.75, 1.23-6.16); and hypertension (1.38, 1.19-1.61). CRSwNP (n = 241) cases were at greater risk for obesity than controls (1.74, 1.08-2.80), but CRSwNP was not associated with other diseases. CONCLUSION: The risk of other diseases associated with CRS adds to the burden of an already highly burdensome condition, and suggests either that CRS promotes onset of other diseases or is an indicator of systemic disease processes. Different patterns of association with diseases by CRS phenotype may be due to CRSwNP sample size limitations or reflect a different pattern of disease onset by phenotype. These findings have implications for screening guidelines and care of CRS patients.

Differential expression of interleukin-32 in chronic rhinosinusitis with and without nasal polyps.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by local inflammation of the upper airways and sinuses and is frequently divided into polypoid CRS (CRSwNP) and nonpolypoid CRS (CRSsNP). However, the mechanism of inflammation in CRS has still not been fully elucidated. The aim of the study was to investigate the role of interleukin-32 (IL-32), a recently discovered proinflammatory cytokine, in CRS. METHODS: We collected nasal epithelial cells and nasal tissue from patients with CRS and control subjects. We assayed mRNA for IL-32 by real-time PCR and measured IL-32 protein using ELISA, Western blot, and immunohistochemistry. RESULTS: The expression of mRNA for IL-32 was elevated in epithelial cells from uncinate tissue from patients with CRSsNP compared with patients with CRSwNP (P < 0.05), control subjects (P=0.06), and epithelial cells from nasal polyp (NP) tissue (P < 0.05). Production of IL-32 was induced by IFN-γ, TNF, and dsRNA in primary airway epithelial cells. In whole-tissue extracts, the expression of IL-32 protein was significantly elevated in patients with CRSwNP compared with patients with CRSsNP and control subjects. Immunohistochemistry data showed that IL-32 was detected in mucosal epithelial cells and inflammatory cells in the lamina propria. Levels of IL-32 were correlated with the levels of CD3 and macrophage mannose receptor in NP tissue. Immunofluorescence data showed IL-32 co-localization with CD3-positive T cells and CD68-positive macrophages in NPs. CONCLUSION: Overproduction of IL-32 may be involved in the pathogenesis of CRS, although the role of IL-32 in the inflammation in CRSsNP and CRSwNP may be different.

Reduced expression of antimicrobial PLUNC proteins in nasal polyp tissues of patients with chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) is a disease characterized by inflammation of the nasal mucosa and paranasal sinuses. This inflammation may result in part from decreased epithelial barrier and innate immune responses, leading to frequent bacterial and fungal colonization. The objectives of this study were to investigate the expression of innate immune proteins of the palate lung and nasal epithelium clone (PLUNC) family in patients with CRS. METHODS: Nasal tissue samples were collected from control subjects and CRS patients with and without nasal polyps. Expression of the members of the PLUNC family was analyzed by real-time PCR. Expression of SPLUNC1 and LPLUNC2 proteins was analyzed by ELISA, immunoblot, and immunohistochemical analysis. RESULTS: Levels of mRNA for most of the members of the PLUNC family were profoundly reduced in nasal polyps (NPs) compared to uncinate tissue from control subjects or patients with CRS. LPLUNC2 and SPLUNC1 proteins were decreased in NPs of patients with CRS compared to uncinate tissue from control subjects. Immunohistochemical data revealed that within submucosal glands of sinonasal tissues, SPLUNC1 and LPLUNC2 were differentially expressed, in serous and mucous cells, respectively. The decrease in the expression of these molecules is probably explained by a decrease in the number of glands in NPs as revealed by correlations with levels of the glandular marker lactoferrin. CONCLUSIONS: Decreased SPLUNC1 and LPLUNC2 in NPs reflect a profound decrease in the number of submucosal glands. Decreased glands may lead to a localized defect in the production and release of glandular innate defense molecules.

Ultrastructural localization of Na+/K(+)-ATPase in rodent olfactory epithelium.

The olfactory epithelium is comprised of bipolar sensory neurons, sustentacular cells, and basal cells. The sensory neurons have apical knobs and cilia, which project into the olfactory mucus toward the nasal lumen, and represent presumptive sites of odorant binding. Ionic currents, measured across this epithelium in both the resting and odorant-stimulated states, are known to be sustained, at least in part, by active transport of sodium. Information identifying the cellular sites of ion transport in olfactory sensory epithelium will therefore aid in elucidating the ionic mechanisms associated with olfactory transduction. The membrane-bound enzyme Na+/K(+)-ATPase mediates active ion transport in many other cells and tissues. We have consequently employed the cytochemical technique reported by Ernst (J. Histochem. Cytochem., 20 (1972) 23-38, 1322) to identify possible sites of elevated Na+/K(+)-ATPase activity in olfactory epithelium. This procedure detects inorganic phosphate (Pi) released from an artificial substrate (nitrophenyl phosphate) by enzyme catalytic activity. In the presence of strontium ion. Pi is precipitated near regions of high enzymatic activity, then converted to a product visible in the electron microscope. Parallel control preparations were incubated in media (1) supplemented with the specific Na+/K(+)-ATPase inhibitor ouabain (to abolish formation of specific reaction product); (2) with substrate deleted (to demonstrate possible non-specific binding of Sr2+ and/or Pb2+); or (3) with the necessary cofactor K+ deleted. In tissues incubated for demonstration of Na+/K(+)-ATPase activity, reaction product was associated with apical knobs, cilia and dendrites of olfactory receptor neurons at the apical surface. In the more proximal region of the epithelium, reaction product was associated with cell bodies and axons of the sensory neurons, and with the lateral membranes of sustentacular cells. Reaction product was deposited intracellularly, compatible with the known mechanism of the Na+/K(+)-ATPase enzymatic reaction. In control specimens incubated with ouabain, with substrate deleted, or with K+ deleted, only a small quantity of non-specific precipitate was observed. These results are discussed with reference to the various sodium currents implicated in olfactory transduction and transepithelial transport.

Cytochemical localization of adenylyl cyclase activity within the sensory epithelium of the trout saccule.

Adenylyl cyclase, the enzyme of synthesis of cAMP, the second messenger molecule mediating signal transduction in response to sensory, neurotransmitter and hormonal stimuli, has been localized in the sensory epithelium of the rainbow trout (Salmo gairdneri R.) saccule by cytochemical detection of enzyme activity. In the sensory receptor cell, or hair cell, reaction product has been visualized in the stereocilia in close association with the outer cell membrane and also at the apical surface of the cuticular plate. A diffuse distribution of precipitate was observed within the cytoplasm of terminal endings of nerve fibers presumed to be efferent on the basis of characteristic synaptic specializations including presynaptic vesicles and a postsynaptic cistern lying within the hair cell. Occasionally, reaction product was observed to be associated with the external cell membrane of these nerve terminals. There appeared to be little or no adenylyl cyclase activity associated with the plasma membrane at the base of the hair cell or in presumptive afferent nerve endings. However, a subpopulation of nerve fiber endings which exhibited both efferent and afferent synaptic specializations contained precipitate. A concentration of adenylyl cyclase activity in hair cell stereocilia and efferent nerve terminals in the sensory epithelium is suggestive of a role for cAMP in second messenger action at these sites, possibly related to mechanosensory transduction and efferent neuromodulation, respectively.

Chronic sinusitis and anosmia: pathologic changes in the olfactory mucosa.

OBJECTIVES: To evaluate histological changes in the olfactory mucosa of patients with chronic rhinosinusitis These results are analyzed in light of current understanding of the pathophysiology of anosmia secondary to nasal and sinus disease. STUDY DESIGN: Prospective study of olfaction on patients undergoing sinus surgery for the management of chronic rhinosinusitis. METHODS: Thirty patients, aged 22 to 39 years, underwent olfactory biopsy at the time of surgery with evaluation by a pathologist. Inflammatory changes were graded as mild (normal), moderate, or severe. Clinical olfactory function was evaluated using the University of Pennsylvania Smell Identification Test (UPSIT). The results correlated with the degree of olfactory dysfunction. RESULTS: Of the 30 patients 19 had unequivocal olfactory mucosa in the biopsy specimen. Eleven had only respiratory or indeterminate mucosa. Nine patients demonstrated normal olfactory mucosa and normal olfactory function (UPSIT > 35). Ten patients demonstrated pathological changes in the olfactory mucosa with an influx of lymphocytes, macrophages, and eosinophils Of these 10 patients, 7 had olfactory deficits as determined by UPSIT. The remaining three patients had normal olfactory function despite moderate chronic inflammation. These studies indicate that the olfactory mucosa is capable of mounting an inflammatory response similar to that seen in the respiratory mucosa of patients with chronic sinusitis These data suggest that the olfactory deficits in these patients may be the result of inflammatory changes within the olfactory mucosa in addition to any alteration in airflow to the olfactory cleft.

Post-traumatic olfactory dysfunction.

OBJECTIVES: This study demonstrates histopathologic and immunocytochemical changes in the olfactory bulb of a patient with post-traumatic olfactory dysfunction. These results are analyzed in light of current understanding of the pathophysiology of anosmia and dysosmia following head trauma. Emphasis is placed on potential mechanisms of human regeneration and recovery. STUDY DESIGN: The current study documents the history of a patient with the initial complaint of complete anosmia following minor head trauma. Two months after the injury the patient developed persistent, severe dysosmia with debilitating weight loss. Neurosurgical treatment, including removal of the olfactory bulbs and tracts, resulted in permanent resolution of dysosmia. METHODS: Histopathologic and immunocytochemical analysis of the olfactory bulbs was undertaken and compared with age-matched control tissue. RESULTS: Pathological analysis of the olfactory bulb revealed a marked reduction in the number of nerve processes with few intact olfactory glomeruli compared with an age-matched control. Specific immunohistochemical staining for the olfactory neuron-specific protein OMP, however, demonstrated the presence of intact axonal projections between the olfactory mucosa and the bulb. CONCLUSIONS: These results support the hypothesis that post-traumatic anosmia involves, at least in part, damage to peripheral olfactory nerve fibers with histological changes in the olfactory bulb. Potential mechanisms for the development of post-traumatic dysosmia are also discussed.

Treatment of olfactory dysfunction, II: studies with minocycline.

OBJECTIVES/HYPOTHESIS: The treatment of anosmia has changed minimally since the early 1970s, despite dramatic advances in the understanding of the molecular biology of olfaction. Recent studies from the authors' laboratory have suggested that most common causes of clinical olfactory dysfunction, including rhinosinusitis, appear to be associated with increased apoptotic death of olfactory sensory neurons. This appears to result in a decline in the number of functioning mature olfactory sensory neurons, despite the capacity of the olfactory epithelium for regeneration. The current study evaluated the ability of the antibiotic minocycline to inhibit olfactory sensory neuron apoptosis. This drug is known to inhibit apoptosis separate from its anti-infective properties. Olfactory sensory neuron apoptosis was triggered by surgical deafferentation ("bulbectomy"), the standard experimental model. Earlier studies have indicated that bulbectomy and sinusitis invoke similar proteolytic enzyme cascades in olfactory sensory neurons. STUDY DESIGN: Histological analysis of animal olfactory tissue. METHODS: Mice underwent unilateral olfactory bulbectomy to induce apoptotic olfactory sensory neuron death, with and without 45 mg/kg intraperitoneal minocycline given 12 hours before surgery and every 12 hours until death. Mice were killed at 2 and 4 days after bulbectomy and assessed for activation of capsase-3 and olfactory sensory neuron survival by immunohistochemical analysis. RESULTS: Minocycline resulted in partial suppression of cell death at 2 days after surgery when compared with untreated animals. CONCLUSION: Minocycline inhibits olfactory sensory neuron death in the face of a potent pro-apoptotic stimulus. This drug is well tolerated and is currently undergoing human trials for the management of a variety of neurological disorders associated with apoptosis. The current results suggest that minocycline may be efficacious in the management of peripheral olfactory loss as well.

Successful in vitro growth of human respiratory epithelium on a tracheal prosthesis.

Reconstruction of tracheal defects may be necessary following trauma or oncologic surgery. Defects up to 8 cm can often be repaired using end-to-end anastomosis. Use of a tracheal prosthesis for larger defects has been complicated by recurrent stenosis and infection. Recent animal studies, utilizing a Dacron polyurethane prosthesis suggest that problems with anastomotic stenosis and infection can be controlled. Problems with a central stenosis within the prosthesis persist when used for defects greater than 6 cm. Establishment of a confluent lining of respiratory epithelium is believed to be necessary for successful prosthetic tracheal reconstruction. Using cell culture techniques, we report the first successful seeding and growth of human respiratory epithelium onto a Dacron polyurethane tracheal prosthesis.

Pathology of the olfactory mucosa: implications for the treatment of olfactory dysfunction.

OBJECTIVE: The pathology of the olfactory mucosa is poorly understood; however, most cases of hyposmia and anosmia appear to be associated with a decline in the number of functioning mature olfactory sensory neurons (OSNs). Under normal conditions, OSNs undergo apoptotic cell death at a baseline rate likely secondary to their exposed location in the nose. Regeneration of mature OSNs from precursors in the epithelium allows the animal to maintain an adequate number of neurons necessary for olfactory sensation. In many cases of olfactory dysfunction, this balance is apparently disturbed, with a net loss of OSNs. The current study will examine normal and diseased olfactory tissue for the presence of data demonstrating that the preferred mechanism of OSN cell death is apoptotic in both health and disease. The potential therapeutic implications will be discussed. STUDY DESIGN: Histologic analysis of human and animal olfactory tissue. METHODS: Normal and diseased human and animal olfactory mucosa were assessed for immunohistochemical evidence of apoptosis. RESULTS: Increased activity of the apoptotic effector enzyme caspase-3 was demonstrated in diseased olfactory mucosa in comparison with normal controls. CONCLUSION: These results indicate that a common pathway may mediate OSN cell death from a diverse set of pathologic insults including aging, trauma, and sinusitis. Interference with this pathway of cell death is currently the subject of intense pharmacotherapeutic research for the management of stroke and meningitis. These drugs may ultimately prove useful in the treatment of clinical olfactory dysfunction.

Olfactory secretion and sodium, potassium-adenosine triphosphatase: regulation by corticosteroids.

OBJECTIVES: To investigate the cellular distribution and relative intensity of the immunoreactivity associated with the expression of sodium, potassium-adenosine triphosphatase (Na, K-ATPase) in cells of the olfactory mucosa. Second, changes in the activity of this enzyme in the olfactory mucosa are correlated with changes in the circulating corticosteroid aldosterone. METHODS: Combination of immunohistochemical and biochemical techniques were employed to examine the olfactory Na, K-ATPase. RESULTS: Within the olfactory epithelium, the Na, K-ATPase immunoreactivity was greatest at the supranuclear region of sustentacular cells and/or dendrites of olfactory receptor neurons (ORNs). Cell bodies of ORNs demonstrated moderate immunoreactivity, whereas the duct cells of Bowman's gland exhibited moderate to intense immunoreactivity. Acinar cells of the Bowman's gland were the most intensely stained components of the lamina propria, exhibiting strong immunoreactivity at the basolateral plasma membrane domains of the acinar cells and less within the cytoplasm. Binding of ouabain, a specific inhibitor of Na, K-ATPase, was significantly elevated for aldosterone-injected versus sham-injected controls. CONCLUSION: These results suggest that olfactory Na, K-ATPase is regulated by the systemic corticosteroid aldosterone. The results are consistent with the hypothesis that corticosteroids regulate olfactory secretion.

Expression of glucocorticoid receptor mRNA and protein in the olfactory mucosa: physiologic and pathophysiologic implications.

OBJECTIVES: Define the presence and distribution of glucocorticoid receptors (GRs) within the olfactory mucosa in order to assess potential physiologic and pathophysiologic effects of these hormones on olfaction. STUDY DESIGN: The olfactory mucosa was harvested from adult male rats and guinea pigs. Kidney tissue was utilized as a known positive control. METHODS: The techniques of reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry were utilized to examine the expression of GR mRNA and protein. To assure the presence of olfactory mucosa in the nasal tissue samples, RT-PCR was utilized to identify the olfactory marker protein (OMP). RESULTS: The presence of GR mRNA was confirmed in both the olfactory mucosa and kidney. GR-like immunoreactivity associated with the olfactory epithelium was greatest at the apical surface, a position corresponding to the dendrites, knobs, and cilia of olfactory receptor neurons, as well as the supranuclear region of sustentacular cells. Weaker GR-like immunoreactivity was associated with the region of the cell bodies of the olfactory receptor neurons. Within the lamina propria, acinar cells of the Bowman's glands and olfactory nerve bundles were intensely immunoreactive. CONCLUSIONS: The presence of GR mRNA and protein within the olfactory mucosa is consistent with a functional role for glucocorticoid hormones in the systemic regulation of olfaction. Furthermore, these studies suggest that corticosteroid medications may have direct effects on the cells of the olfactory mucosa in the pathologic state. The potential mechanisms whereby these hormones may act are discussed.