Nasonasal reflexes, the nasal cycle, and sneeze

Neural mechanisms of respiratory interoception

Respiratory interoception is one of the internal bodily systems that is comprised of different types of somatic and visceral sensations elicited by different patterns of afferent input and respiratory motor drive mediating multiple respiratory modalities. Respiratory interoception is a complex system, having multiple afferents grouped into afferent clusters and projecting into both discriminative and affective centers that are directly related to the behavioral assessment of breathing. The multi-afferent system provides a spectrum of input that result in the ability to interpret the different types of respiratory interceptive sensations. This can result in a response, commonly reported as breathlessness or dyspnea. Dyspnea can be differentiated into specific modalities. These respiratory sensory modalities lead to a general sensation of an Urge-to-Breathe, driven by a need to compensate for the modulation of ventilation that has occurred due to factors that have affected breathing. The multiafferent system for respiratory interoception can also lead to interpretation of the sensory signals resulting in respiratory related sensory experiences, including the Urge-to-Cough and Urge-to-Swallow. These behaviors are modalities that can be driven through the differentiation and integration of multiple afferent input into the respiratory neural comparator. Respiratory sensations require neural somatic and visceral interoceptive elements that include gated attention and detection leading to respiratory modality discrimination with subsequent cognitive decision and behavioral compensation. Studies of brain areas mediating cortical and subcortical respiratory sensory pathways are summarized and used to develop a model of an integrated respiratory neural network mediating respiratory interoception.

SARS-CoV-2 papain-like protease activates nociceptors to drive sneeze and pain

SARS-CoV-2, the virus responsible for COVID-19, triggers symptoms such as sneezing, aches and pain.1 These symptoms are mediated by a subset of sensory neurons, known as nociceptors, that detect noxious stimuli, densely innervate the airway epithelium, and interact with airway resident epithelial and immune cells.2-6 However, the mechanisms by which viral infection activates these neurons to trigger pain and airway reflexes are unknown. Here, we show that the coronavirus papain-like protease (PLpro) directly activates airway-innervating trigeminal and vagal nociceptors in mice and human iPSC-derived nociceptors. PLpro elicits sneezing and acute pain in mice and triggers the release of neuropeptide calcitonin gene-related peptide (CGRP) from airway afferents. We find that PLpro-induced sneeze and pain requires the host TRPA1 ion channel that has been previously demonstrated to mediate pain, cough, and airway inflammation.7-9 Our findings are the first demonstration of a viral product that directly activates sensory neurons to trigger pain and airway reflexes and highlight a new role for PLpro and nociceptors in COVID-19.

Assessing Nasal Epithelial Dynamics: Impact of the Natural Nasal Cycle on Intranasal Spray Deposition

This study investigated the intricate dynamics of intranasal spray deposition within nasal models, considering variations in head orientation and stages of the nasal cycle. Employing controlled delivery conditions, we compared the deposition patterns of saline nasal sprays in models representing congestion (N1), normal (N0), and decongestion (P1, P2) during one nasal cycle. The results highlighted the impact of the nasal cycle on spray distribution, with congestion leading to confined deposition and decongestion allowing for broader dispersion of spray droplets and increased sedimentation towards the posterior turbinate. In particular, the progressive nasal dilation from N1 to P2 decreased the spray deposition in the middle turbinate. The head angle, in conjunction with the nasal cycle, significantly influenced the nasal spray deposition distribution, affecting targeted drug delivery within the nasal cavity. Despite controlled parameters, a notable variance in deposition was observed, emphasizing the complex interplay of gravity, flow shear, nasal cycle, and nasal morphology. The magnitude of variance increased as the head tilt angle increased backward from upright to 22.5° to 45° due to increasing gravity and liquid film destabilization, especially under decongestion conditions (P1, P2). This study's findings underscore the importance of considering both natural physiological variations and head orientation in optimizing intranasal drug delivery.

Fitostimoline® in fibro-endoscopic and trans-nasal trans-speculum septoplasty as a beneficial tool to improve post-surgical outcome: Preliminary results of a case-control study

OBJECTIVES

Topic treatment can be useful to improve short and long-term nasal outcomes after nasal surgery, reducing discomfort and risk of synechia. This study aimed at evaluating the effect on clinical outcomes of nasal packaging using Fitostimoline® gauze in FESS and septoplasty.

METHODS

A case-control study on hospitalized patients was performed in a tertiary referral center. The control group included 20 patients treated with the standard surgical protocol for septoplasty and standard nasal packaging; treatment group included 21 patients underwent same surgical procedure but in whom the nasal tampon was wrapped with a gauze containing Fitostimoline® before being placed into the nose.

RESULTS

Patients in treatment group had better outcomes than control; nasal mucosa showed better healing - recovery of normal color- in those patients in whom we applied the Fitostimoline® gauze around tampons. Moreover, 100 % patients in the treatment group did not refer discomfort during at tampon removal versus 60 % subjects in the control group who referred pain, tension or tearing during the same action.

CONCLUSION

Our results, although preliminary because of the small cohort of subjects included, suggest that the apposition of a gauze with Fitostimoline® after nasal surgery might improve the mucosal healing with consequent reduction of patients discomfort during the post-surgical period.

Trigeminal Sensitivity in Patients With Allergic Rhinitis and Chronic Rhinosinusitis

OBJECTIVE

Allergic rhinitis (AR) and chronic rhinosinusitis with nasal polyps (CRSwNP) are of high importance in otorhinolaryngology. Some of their symptoms are related to changes in the nasal trigeminal sensitivity. The aim of this study was to compare nasal trigeminal sensitivity in patients with AR, CRSwNP, and healthy controls (HC).

METHODS

A total of 75 individuals participated (age 19-78 years; 34 AR, 10 CRSwNP and 31 HC). Olfactory function was determined using the extended Sniffin' Sticks test battery. Trigeminal sensitivity was assessed with CO₂ detection thresholds. Trigeminal negative mucosal potentials (NMP) and EEG-derived event-related potentials (ERP) were recorded in response to selective olfactory (phenylethyl alcohol) and trigeminal (CO₂ ) stimuli using high-precision air-dilution olfactometry.

RESULTS

In comparison to HC, AR patients had lower CO₂ thresholds, also reflected in shorter peak latencies in NMP and trigeminal ERP measurements. CRSwNP patients had a decreased sensitivity for trigeminal stimuli, also reflected in prolonged trigeminal ERP latencies, and reduced olfactory function compared to HC.

CONCLUSION

AR patients seemed to be more sensitive to trigeminal stimuli than CRSwNP patients. Importantly, the differences could be shown on psychophysical and electrophysiological levels. The changes in trigeminal sensitivity appear to be present already at the level of the respiratory epithelium. The differences between the two groups may depend on the specific inflammatory changes accompanying each disorder, the degree of inflammatory activity, or duration of the inflammatory disorder. However, because the sample sizes are relatively small, these results need to be confirmed in the future studies with larger groups.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:654-660, 2023.

Cannabis Use and Sinonasal Symptoms in US Adults

Importance

Cannabis is the most commonly used illicit substance in the US and worldwide. Understanding the association between cannabis use and sinonasal symptoms may help clinicians and patients better understand the symptomatology associated with cannabis use.

Objective

To assess the association between frequency of cannabis use and presence of sinonasal symptoms in a nationally representative sample of US adults.

Design, Setting, and Participants

This population-based, retrospective cross-sectional study included adults aged 20 to 69 years who had completed data on sinonasal symptoms and substance use for the 2013 to 2014 National Health and Nutrition Examination Survey. The data were analyzed in February 2022.

Exposures

Cannabis use frequency.

Main Outcomes and Measures

Presence of sinonasal symptoms, demographic information, and medical history were obtained from National Health and Nutrition Examination Survey questionnaires. Presence of any sinonasal symptoms was defined as responding yes to any of a series of questions assessing rhinologic symptoms. Regular cannabis users were defined as using cannabis 15 or more times within the last 30 days. Nonregular users were defined as using cannabis fewer than 15 times within the last 30 days. Multivariable models were used to examine the association between frequency of cannabis use and presence of sinonasal symptoms while adjusting for demographic characteristics and medical comorbidities.

Results

The study included 2269 adults with a mean (SD) age of 36.5 (12.4) years (1207 women [53.2%]; 330 Asian [14.5%], 739 Black [32.6%], 461 Hispanic [20.3%], and 656 White [28.9%] individuals). The prevalence of sinonasal symptoms among regular cannabis users (45.0%; 95% Cl, 38.9%-51.1%) was lower than the prevalence among never users (64.5%; 95% Cl, 58.3%-68.8%). Compared with adults who had never used cannabis, regular cannabis users were less likely to have sinonasal symptoms (odds ratio, 0.22, 95% CI, 0.10-0.50). Current tobacco smokers were more likely to have sinonasal symptoms (odds ratio, 1.96; 95% CI, 1.17-3.28). The most common sinonasal symptoms reported were nasal congestion (62.8%; 95% Cl, 60.2%-65.4%) and change in smell (17.8%; 95% Cl, 15.2%-20.9%).

Conclusions and Relevance

This cross-sectional study found that the prevalence of sinonasal symptoms was lower among regular cannabis users. Further research is needed to elucidate the mechanisms underlying the association between cannabis use and sinonasal symptoms.

Nicotinic acetylcholine receptor stimulation: A new approach for stimulating tear secretion in dry eye disease

Tear secretion is regulated by the lacrimal functional unit consisting of afferent and efferent nerve innervation. The afferent arm consists of trigeminal nociceptors on the ocular surface and nasal mucosa. When stimulated by agonists, nicotinic acetylcholine receptors on nerve endings in the nose initiate a reflex arc resulting in instantaneous tear secretion. Pharmacologic nasal neural stimulation to increase endogenous tear production is a novel approach to treating dry eye disease.

Concha Bullosa of the Inferior Turbinate

Inferior concha bullosa is a rare disease that has been related to sinonasal symptoms. This study aimed to determine the characteristics of concha bullosa in the inferior turbinate and assess its common clinical manifestations, computed tomography findings, and the surgical techniques used to treat the condition. We conducted a search of the PubMed database, using the Preferred Reporting Items of Systematic Reviews and Meta-Analysis, for articles published until May 2021 using the following terms: "inferior turbinate and concha bullosa"; "inferior turbinate and pneumatization"; and in combination with other terms such as "concha bullosa release and concha bullosa excision", among others. We found 12 papers that met our inclusion criteria. The main presenting symptom was a nasal obstruction in 13 patients (100%), followed by headache in 10 patients (77%). The site of inferior concha bullosa was bilateral in six cases and left-sided in five cases. Computed tomography was conducted in all cases in this review. The type of intervention performed was medical, surgical, and both in 23%, 54%, and 23% of the cases. Despite multimodal surgical approaches and medical treatment, all the outcomes were good and no compactions were noted. All cases also had good prognoses.

Prevalence, comorbidities, diagnosis, and treatment of nonallergic rhinitis: real-world comparison with allergic rhinitis

Rhinitis is among the most common respiratory diseases in children. Nonallergic rhinitis, which involves nasal symptoms without evidence of systemic allergic inflammation or infection, is a heterogeneous entity with diverse manifestations and intensities. Nonallergic rhinitis accounts for 16%-89% of the chronic rhinitis cases, affecting 1%-50% (median 10%) of the total pediatric population. The clinical course of nonallergic rhinitis is generally rather mild and less likely to be associated with allergic comorbidities than allergic rhinitis. Here, we aimed to estimate the rate of coexisting comorbidities of nonallergic rhinitis. Nonallergic rhinitis is more prevalent during the first 2 years of life; however, its underestimation for children with atopic tendencies is likely due to low positive rates of specific allergic tests during early childhood. Local allergic rhinitis is a recently noted phenotype with rates similar to those in adults (median, 44%; range, 4%-67%), among patients previously diagnosed with nonallergic rhinitis. Idiopathic rhinitis, a subtype of nonallergic rhinitis, has been poorly studied in children, and its rates are known to be lower than those in adults. The prevalence of nonallergic rhinitis with eosinophilia syndrome is even lower. A correlation between nonallergic rhinitis and pollution has been suggested owing to the recent increase in nonallergic rhinitis rates in highly developing regions such as some Asian countries, but many aspects remain unknown. Conventional treatments include antihistamines, intranasal corticosteroids, and recent treatments include combination of intranasal corticosteroids with azelastin or decongestants. Here we review the prevalence, diagnosis, comorbidities, and treatment recommendations for nonallergic rhinitis versus allergic rhinitis in children.

Correlation between nasal mucosal temperature change and the perception of nasal patency: a literature review

BACKGROUND

The mechanism of nasal airflow sensation is poorly understood. This study aimed to examine the role of nasal mucosal temperature change in the subjective perception of nasal patency and the methods by which it can be quantified.

METHOD

Medline and PubMed database searches were performed to retrieve literature relevant to the topic.

RESULTS

The primary mechanism producing the sensation of nasal patency is thought to be the activation of transient receptor potential melastatin family member 8 ('TRPM8'), a thermoreceptor that is activated by nasal mucosal cooling. Computational fluid dynamics studies have demonstrated that increased airflow and heat flux are correlated with better patient-reported outcome measure scores. Similarly, physical measurements of the nasal cavity using temperature probes have shown a correlation between lower nasal mucosal temperatures and better patient-reported outcome measure scores.

CONCLUSION

Nasal mucosal temperature change may be correlated with the perception of improved nasal patency. Future research should quantify the impact of mucosal cooling on the perception of nasal airway obstruction.

Spatiotemporal Processing of Bimodal Odor Lateralization in the Brain Using Electroencephalography Microstates and Source Localization

The neuronal cascade related to the perception of either purely olfactory or trigeminal airborne chemicals has been investigated using electroencephalography (EEG) microstate analyses and source localization. However, most airborne chemicals are bimodal in nature, encompassing both properties. Moreover, there is an ongoing debate regarding whether there is one dominant nostril, and this could be investigated using these multichannel EEG methods. In this study, 18 right-handed, healthy participants (13 females) were monorhinally stimulated using an olfactometer with the bimodal component acetic acid during continuous EEG recording. Participants indicated the side of stimulation, the confidence in their decision, and rated the strength of the evoked perception. EEG microstate clustering determined four distinct maps and successive backfitting procedures, and source estimations revealed a network that evolved from visual-spatial processing areas to brain areas related to basic olfactory and trigeminal sensations (e.g., thalamus, cingulate cortex, insula, parahippocampal, and pre-/post-central gyri) and resulted in activation of areas involved in multisensory integration (e.g., frontal-temporal areas). Right-nostril stimulation was associated with faster microstate transition and longer involvement of the superior temporal gyrus, which was previously linked to chemical localization and provides evidence for a potential nostril dominance. The results describe for the first time the processing cascade of bimodal odor perception using microstate analyses and demonstrate its feasibility to further investigate potential nostril dominance.

Non-Reflex Defense Mechanisms of Upper Airway Mucosa: Possible Clinical Application

The sinonasal mucosa has an essential role in defense mechanisms of the upper respiratory tract. The innate immune system presents the primary defense against noxious microorganisms followed by induction of the adaptive immune mechanisms as a consequence of the presence of pathogens. This well-known activation of adaptive immune system in response to presence of the antigen on mucosal surfaces is now broadly applicated in vaccinology research. Prevention of infectious diseases belongs to substantial challenges in maintaining the population health. Non-invasive, easily applicable mucosal vaccination purposes various research opportunities that could be usable in daily practice. However, the existence of multiple limitations such as rapid clearance of vaccine from nasal mucosa by means of mucociliary transport represents a great challenge in development of safe and efficient vaccines. Here we give an updated view on nasal functions with focus on nasal mucosal immunity and its potential application in vaccination in nearly future.

Medical devices in allergy practice

Medical devices provide people with some health benefits in terms of diagnosis, prevention, treatment, and monitoring of disease processes. Different medical specialties use varieties of medical devices more or less specific for them. Allergology is an interdisciplinary field of medical science and teaches that allergic reactions are of systemic nature but can express themselves at the level of different organs across the life cycle of an individual. Subsequently, medical devices used in allergology could be regarded as: 1) general, servicing the integral diagnostic and management principles and features of allergology, and 2) organ specific, which are shared by organ specific disciplines like pulmonology, otorhinolaryngology, dermatology, and others. The present position paper of the World Allergy Organization (WAO) is meant to be the first integral document providing structured information on medical devices in allergology used in daily routine but also needed for sophisticated diagnostic purposes and modern disease management. It is supposed to contribute to the transformation of the health care system into integrated care pathways for interrelated comorbidities.

Neurokinin-1 receptor activation is sufficient to restore the hypercapnic ventilatory response in the Substance P-deficient naked mole-rat

Naked mole-rats (NMRs) live in large colonies within densely populated underground burrows. Their collective respiration generates significant metabolic carbon dioxide (CO₂) that diffuses slowly out of the burrow network, creating a hypercapnic environment. Currently, the physiological mechanisms that underlie the ability of NMRs to tolerate environmental hypercapnia are largely unknown. To address this, we used whole-body plethysmography and respirometry to elucidate the hypercapnic ventilatory and metabolic responses of awake, freely behaving NMRs to 0%-10% CO₂. We found that NMRs have a blunted hypercapnic ventilatory response (HCVR): ventilation increased only in 10% CO₂. Conversely, metabolism was unaffected by hypercapnia. NMRs are insensitive to cutaneous acid-based pain caused by modified substance P (SP)-mediated peripheral neurotransmission, and SP is also an important neuromodulator of ventilation. Therefore, we re-evaluated physiological responses to hypercapnia in NMRs after an intraperitoneal injection of exogenous substance P (2 mg/kg) or a long-lived isoform of substance P {[pGlu5-MePhe8-MeGly9]SP(5-11), DiMe-C7; 40-400 μg/kg}. We found that both drugs restored hypercapnia sensitivity and unmasked an HCVR in animals breathing 2%-10% CO₂. Taken together, our findings indicate that NMRs are remarkably tolerant of hypercapnic environments and have a blunted HCVR; however, the signaling network architecture required for a "normal" HCVR is retained but endogenously inactive. This muting of chemosensitivity likely suits the ecophysiology of this species, which presumably experiences hypercapnia regularly in their underground niche.

The role of motile cilia in the development and physiology of the nervous system

Motile cilia are miniature, whip-like organelles whose beating generates a directional fluid flow. The flow generated by ciliated epithelia is a subject of great interest, as defective ciliary motility results in severe human diseases called motile ciliopathies. Despite the abundance of motile cilia in diverse organs including the nervous system, their role in organ development and homeostasis remains poorly understood. Recently, much progress has been made regarding the identity of motile ciliated cells and the role of motile-cilia-mediated flow in the development and physiology of the nervous system. In this review, we will discuss these recent advances from sensory organs, specifically the nose and the ear, to the spinal cord and brain ventricles. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.

Randomized, Controlled, Double-Masked, Multicenter, Pilot Study Evaluating Safety and Efficacy of Intranasal Neurostimulation for Dry Eye Disease

Purpose

We assess the safety and effectiveness of intranasal neurostimulation to promote tear production via the nasolacrimal pathway in subjects with dry eye disease.

Methods

A multicenter, randomized, controlled, double-masked pilot study was conducted in adults with dry eye diagnosis and at least one eye with corneal fluorescein staining ≥2 in at least one region or a sum of all regions ≥5 (National Eye Institute grading), basal Schirmer test score ≤10 mm, a cotton-swab stimulated Schirmer score ≥7 mm higher, and an Ocular Surface Disease Index score ≥23. Subjects were randomized to receive active intranasal neurostimulation or sham control intranasal stimulation 4 to 8 times per day. Assessments were scheduled before (unstimulated) and during (stimulated) device application at days 0, 7, 14, 30, and 90. The primary effectiveness endpoint was stimulation-induced change in Schirmer test (with anesthesia) score. Primary safety measure was incidence of device-related adverse events (AEs).

Results

Fifty-eight subjects were randomized at nine sites in Australia and New Zealand; 56 completed the 90-day study. Stimulation-induced change in Schirmer score was significantly greater with active intranasal (mean ± SEM, 9.0 ± 2.0) than sham control intranasal stimulation (0.4 ± 0.6; P < 0.001) at day 90. Similar results were observed at days 0, 7, 14, and 30 (P < 0.001). No serious device-related AEs were observed. Mild nosebleed, the most common device-related AE, was reported in five (16.7%) subjects.

Conclusions

Intranasal neurostimulation was effective in inducing acute tear production after 90 days of use and generally was well tolerated in subjects with dry eye disease.

Unilateral Rhinorrhea and Sneezing After Upper Gastrointestinal Endoscopy Under Intravenous Propofol Sedation With Supplemental Oxygen Administered via a Nasal Cannula: A Case Report

We present a rarely described complication of unilateral rhinorrhea and sneezing in a patient who received intravenous sedation with propofol and supplemental oxygen via a nasal cannula during upper gastrointestinal endoscopy. The literature is reviewed and a mechanism is proposed. Mechanical irritation of the nasal mucosa is felt to be the trigger. Suggestions to avoid and to treat are offered.

The Dangers of Sneezing: A Review of Injuries

BACKGROUND

Sneezing is an almost universal daily phenomenon as a reflex to evacuate irritants from the nasal cavities. An autonomic-controlled buildup of intrathoracic pressure against a closed glottis followed by sudden release results in a burst of 1 kPa of air through the upper airway. Active intervention to limit a sneeze can be deleterious. Closure of the airway during a sneeze can result in over 20 times the airway pressures resulting in a variety of untoward events. This review summarizes all reported injuries that occurred as the result of a sneeze.

OBJECTIVE

The objective of this review is to summarize the risks of closed-airway sneezing and determine if there are any trends which can help understand such injuries.

METHODS

A comprehensive literature review was performed from 1948 to 2018 to identify all reports of sneeze-related injuries. Information was compiled from reports to gain insights into comorbidities and risk factors for sneeze injuries.

RESULTS

There were 52 unique reports of sneeze-related injuries in the literature that were categorized into 6 areas of injury: intrathoracic, laryngeal/pharyngeal, ocular/orbital, intracranial/neurological, otologic, and other. The mean age of subjects who suffered a sneeze injury was 40 years old (range: 15-84 years), with 81% being male gender. Thirty percent had a risk factor for injury of prior trauma (5) or respiratory compromise (5).

CONCLUSION

A variety of injuries can occur during a sneeze, especially when a closed-airway sneeze is attempted, and high Valsalva pressure is transmitted to the other systems. Men are more at risk for these injuries with the majority occurring in patients with no known risk factor. When triggered, a sneeze should be allowed to proceed without intervention to prevent associated injuries.

Rhinitis and Sinusitis

Rhinitis is defined as inflammation of the nose, which can extend into and affect the sinuses. The term rhinosinusitis is used to describe inflammation of both the nose and the sinuses. An example of rhinitis is allergic rhinitis, caused by sensitization and exposure to aeroallergens, which, along with other allergic diseases, such as asthma, affect up to one-third of women in the childbearing age. The most common type of rhinosinusitis is infectious, either acute or chronic, which commonly occurs secondarily to a viral respiratory tract infection. Both rhinitis and rhinosinusitis significantly affect the quality of life. The purpose of this chapter is to introduce and describe the differential diagnosis and treatment of these two common clinical entities during pregnancy.

Characterization of tear production in subjects with dry eye disease during intranasal tear neurostimulation: Results from two pivotal clinical trials

PURPOSE

The intranasal tear neurostimulator (ITN) activates the nasolacrimal pathway, which is involved with basal and bolus tear secretion. These studies characterized the acute and long-term effectiveness of the ITN in stimulating tear production in subjects with dry eye disease (DED).

METHODS

Study 1: Randomized, double-masked, dual-controlled, 1-day crossover. Study 2: Single-arm, open-label, 180-day prospective cohort. Eligible subjects had basal unstimulated Schirmer test (with anesthesia) ≤10 mm and intranasal cotton swab-stimulated Schirmer test at least 7 mm greater in the same eye, and Ocular Surface Disease Index^® ≥13 and ≥ 23, in Studies 1 and 2, respectively. Study 1: Subjects (n = 48) received three randomized test applications: active intranasal, extranasal (active control), and sham intranasal (inactive control) stimulation, 3 min/application with 1-hour minimum between applications. Primary outcome measure was the difference in Schirmer test scores during active intranasal and control applications. Study 2: Subjects (n = 97) performed intranasal neurostimulation for ≤3 min/application, 2-10 times/day. Primary outcome measure was the difference in Schirmer scores (stimulated minus unstimulated) at day 180. Both studies recorded device-related adverse events (AEs).

RESULTS

Study 1: Schirmer scores (mean ± SEM) were significantly greater (p < 0.0001) with active intranasal (25.3 ± 1.5 mm) vs extranasal (9.5 ± 1.2 mm) and sham (9.2 ± 1.1 mm) applications. Study 2: Schirmer scores were significantly greater (p < 0.0001) with ITN stimulation vs unstimulated at day 180 (17.3 ± 1.3 mm vs 7.9 ± 0.7 mm). No serious device-related AEs were reported in either study.

CONCLUSION

The ITN was well-tolerated and effective in stimulating tear production with acute and long-term use in DED. CLINICALTRIALS.

GOV IDENTIFIER

NCT02680158 and NCT02526290.

Effects of "trigeminal training" on trigeminal sensitivity and self-rated nasal patency

Purpose

Patients with the feeling of a congested nose not always suffer from an anatomical obstruction but might just have a low trigeminal sensibility, which prevents them from perceiving the nasal airstream. We examined whether intermittent trigeminal stimulation increases sensitivity of the nasal trigeminal nerve and whether this effect is accompanied by subjective improvement of nasal breathing.

Method

Thirty-five patients (M_age = 58.4 years; SD = 14.8; Min_age = 21 years; Max_age = 79 years; 43% females) and 30 healthy controls (M_age = 36.7 years, SD = 14.5; Min_age = 20 years; Max_age = 73 years; 60% females) participated in a study comprised of two sessions separated by “trigeminal training”. During each session, trigeminal sensitivity towards CO₂, trigeminal lateralization abilities and ratings of nasal patency were assessed. Age and training compliance were controlled.

Results

“Trigeminal training” had a positive effect on trigeminal sensitivity in both groups, (p = .027) and this effect depended on the training compliance (p < .001). “Trigeminal training” had no effect on lateralization abilities of the subjects (p > .05). Ratings of nasal patency increased in patients (p = .03), but not in controls.

Conclusions

“Trigeminal training” consisting of intermittent presentation of diverse stimulants leads to an increase of trigeminal sensitivity, but this effect depended on the training compliance. Importantly, in patients, this training is also associated with an increase in self-rated nasal patency.

Autonomic nervous system dysfunction and sinonasal symptoms

Background

The autonomic nervous system (ANS) richly innervates the nose and paranasal sinuses, and has a significant role in lower airway diseases, e.g., asthma. Nonetheless, its contribution to sinonasal symptoms is poorly understood. This review aimed to explore the complex relationship between the ANS and sinonasal symptoms, with reference to systemic diseases and triggers of ANS dysfunction.

Methods

A review of articles published in English was conducted by searching medical literature databases with the key words “autonomic nervous system” and (“sinusitis” or “nose” or “otolaryngology”). All identified abstracts were reviewed, and, from these, relevant published whole articles were selected.

Results

The ANS has a significant role in the pathophysiologic mechanisms that produce sinonasal symptoms. There was limited evidence that describes the relationship of the ANS in sinonasal disease with systemic conditions, e.g. hypertension. There was some evidence to support mechanisms related to physical and psychological stressors in this relationship.

Conclusion

The role of ANS dysfunction in sinonasal disease is highly complex. The ANS sits within a web of multiple factors, including personality and psychological distress, that contribute to sinonasal symptoms. Further research will help to clarify the etiology of ANS dysfunction and its contribution to common systemic conditions.

Clinical Practice Guideline: Improving Nasal Form and Function after Rhinoplasty

Objective Rhinoplasty, a surgical procedure that alters the shape or appearance of the nose while preserving or enhancing the nasal airway, ranks among the most commonly performed cosmetic procedures in the United States, with >200,000 procedures reported in 2014. While it is difficult to calculate the exact economic burden incurred by rhinoplasty patients following surgery with or without complications, the average rhinoplasty procedure typically exceeds $4000. The costs incurred due to complications, infections, or revision surgery may include the cost of long-term antibiotics, hospitalization, or lost revenue from hours/days of missed work. The resultant psychological impact of rhinoplasty can also be significant. Furthermore, the health care burden from psychological pressures of nasal deformities/aesthetic shortcomings, surgical infections, surgical pain, side effects from antibiotics, and nasal packing materials must also be considered for these patients. Prior to this guideline, limited literature existed on standard care considerations for pre- and postsurgical management and for standard surgical practice to ensure optimal outcomes for patients undergoing rhinoplasty. The impetus for this guideline is to utilize current evidence-based medicine practices and data to build unanimity regarding the peri- and postoperative strategies to maximize patient safety and to optimize surgical results for patients. Purpose The primary purpose of this guideline is to provide evidence-based recommendations for clinicians who either perform rhinoplasty or are involved in the care of a rhinoplasty candidate, as well as to optimize patient care, promote effective diagnosis and therapy, and reduce harmful or unnecessary variations in care. The target audience is any clinician or individual, in any setting, involved in the management of these patients. The target patient population is all patients aged ≥15 years. The guideline is intended to focus on knowledge gaps, practice variations, and clinical concerns associated with this surgical procedure; it is not intended to be a comprehensive reference for improving nasal form and function after rhinoplasty. Recommendations in this guideline concerning education and counseling to the patient are also intended to include the caregiver if the patient is <18 years of age. Action Statements The Guideline Development Group made the following recommendations: (1) Clinicians should ask all patients seeking rhinoplasty about their motivations for surgery and their expectations for outcomes, should provide feedback on whether those expectations are a realistic goal of surgery, and should document this discussion in the medical record. (2) Clinicians should assess rhinoplasty candidates for comorbid conditions that could modify or contraindicate surgery, including obstructive sleep apnea, body dysmorphic disorder, bleeding disorders, or chronic use of topical vasoconstrictive intranasal drugs. (3) The surgeon, or the surgeon's designee, should evaluate the rhinoplasty candidate for nasal airway obstruction during the preoperative assessment. (4) The surgeon, or the surgeon's designee, should educate rhinoplasty candidates regarding what to expect after surgery, how surgery might affect the ability to breathe through the nose, potential complications of surgery, and the possible need for future nasal surgery. (5) The clinician, or the clinician's designee, should counsel rhinoplasty candidates with documented obstructive sleep apnea about the impact of surgery on nasal airway obstruction and how obstructive sleep apnea might affect perioperative management. (6) The surgeon, or the surgeon's designee, should educate rhinoplasty patients before surgery about strategies to manage discomfort after surgery. (7) Clinicians should document patients' satisfaction with their nasal appearance and with their nasal function at a minimum of 12 months after rhinoplasty. The Guideline Development Group made recommendations against certain actions: (1) When a surgeon, or the surgeon's designee, chooses to administer perioperative antibiotics for rhinoplasty, he or she should not routinely prescribe antibiotic therapy for a duration >24 hours after surgery. (2) Surgeons should not routinely place packing in the nasal cavity of rhinoplasty patients (with or without septoplasty) at the conclusion of surgery. The panel group made the following statement an option: (1) The surgeon, or the surgeon's designee, may administer perioperative systemic steroids to the rhinoplasty patient.

Concentration-dependent effects of PM2.5 mass on expressions of adhesion molecules and inflammatory cytokines in nasal mucosa of rats with allergic rhinitis

Allergic rhinitis (AR) represents a clinical health issue affecting approximately 500 million people worldwide. This study aimed to explore the effects of airborne fine particulate matter (PM_2.5) on the nasal mucosa of rats with AR. Seventy-five healthy male SD rats were included and randomly divided into the normal, model, low-concentration, middle-concentration, and high-concentration groups (15 rats each group). AR rat models were established using sensitized mixture and were stimulated using different concentrations of PM_2.5. Sneeze and nose-scratching events were observed. Automatic hematology analyzer was utilized to count white blood cells (WBCs). The serum IgE, ICAM-1, and VCAM-1 expressions, eosinophil (EOS) infiltration, and IFN-γ, IL-4, IL-5, IL-33, and TSLP expressions were detected by ELISA, HE staining, and qRT-PCR. Greater numbers of WBCs, increased IgE level, elevated levels of ICAM-1, VCAM-1, EOS, IFN-γ, IL-4, IL-5, IL-33, and TSLP in the model, low-concentration, middle-concentration, and high-concentration groups than the normal group. The same trend also exhibited in rats of the middle-concentration and high-concentration groups than that of the model and low-concentration groups. Comparisons between normal rats and AR rats indicated that AR rats exhibit remarkably higher cytokine expression levels of IFN-γ, IL-4, IL-5, TSLP, and IL-33. The study revealed that as stimulation is triggered by PM_2.5, AR rats result in increased levels of adhesion molecules and inflammatory cytokine expressions in a concentration-dependent manner. Analyses of PM_2.5 as well as, its effects on AR are crucial in the continued drive for both prevention and management of the disease.

Role of oxidative stress & transient receptor potential in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) affect millions of people worldwide and is known to be one of the leading causes of death. The highly sensitive airways protect themselves from irritants by cough and sneeze which propel endogenous and exogenous substances to minimize airway noxious effects. One noxious effect of these substances is activation of peripheral sensory nerve endings of nociceptor neurons innervating these airways lining thus transmitting dangerous signals from the environment to the central nervous system (CNS). Nociceptor neurons include transient receptor potential (TRP) ion channels, especially the vanilloid and ankyrin subfamilies, TRPV1/A1 which can be activated by noxious chemical challenges in models of airways disease. As oxidative stress may activate airways sensory neurons and contribute to COPD exacerbations we sought to review the role that TRP channel activation by oxidative signals may have on airway responses. It would be prudent to target the TRP channels with antagonists and lower systemic oxidative stress with agents that can modulate TRP expression and boost the endogenous levels of antioxidants for treatment and management of COPD.

The involvement of TRP channels in sensory irritation: a mechanistic approach toward a better understanding of the biological effects of local irritants

Peripheral nerves innervating the mucosae of the nose, mouth, and throat protect the organism against chemical hazards. Upon their stimulation, characteristic perceptions (e.g., stinging and burning) and various reflexes are triggered (e.g., sneezing and cough). The potency of a chemical to cause sensory irritation can be estimated by a mouse bioassay assessing the concentration-dependent decrease in the respiratory rate (50 % decrease: RD50). The involvement of the N. trigeminus and its sensory neurons in the irritant-induced decrease in respiratory rates are not well understood to date. In calcium imaging experiments, we tested which of eight different irritants (RD50 5-730 ppm) could induce responses in primary mouse trigeminal ganglion neurons. The tested irritants acetophenone, 2-ethylhexanol, hexyl isocyanate, isophorone, and trimethylcyclohexanol stimulated responses in trigeminal neurons. Most of these responses depended on functional TRPA1 or TRPV1 channels. For crotyl alcohol, 3-methyl-1-butanol, and sodium metabisulfite, no activation could be observed. 2-ethylhexanol can activate both TRPA1 and TRPV1, and at low contractions (100 µM) G protein-coupled receptors (GPCRs) seem to be involved. GPCRs might also be involved in the mediation of the responses to trimethylcyclohexanol. By using neurobiological tools, we showed that sensory irritation in vivo could be based on the direct activation of TRP channels but also on yet unknown interactions with GPCRs present in trigeminal neurons. Our results showed that the potency suggested by the RD50 values was not reflected by direct nerve-compound interaction.

Decrease of nasal airway resistance and alleviations of symptoms after balloon sinuplasty in patients with isolated chronic rhinosinusitis: a prospective, randomised clinical study

OBJECTIVES

The aim of this study was to evaluate and compare the clinical outcome of balloon sinuplasty and uncinectomy for patients suffering from isolated chronic rhinosinusitis of the maxillary sinus.

DESIGN

A prospective, randomised, non-blinded, controlled trial was conducted.

SETTING

The study was carried out at the Department of Otolaryngology, Tampere University Hospital, Finland.

PARTICIPANTS

Adult patients with symptomatic isolated chronic or recurrent rhinosinusitis without severe findings in the sinuses, as documented in the sinus' Computer Tomography scan and clinical examination, were randomised into two groups: uncinectomy and balloon sinuplasty.

MAIN OUTCOME MEASURES

The variables in our study are the Sinonasal Outcome Test-22 (SNOT 22), acoustic rhinometry and rhinomanometry. These parameters were analysed preoperatively and postoperatively (after 3 and 6 months).

RESULTS

The preliminary results of our study have been previously published. Both balloon sinuplasty and uncinectomy significantly improved almost all the parameters of SNOT22 (P < 0.05), with no significant difference being found between these two groups (P > 0.05). Based on rhinomanometry results, airway resistance decreased after treatment. Regarding adverse effects, balloon sinuplasty was significantly associated with a lesser risk of synechia.

CONCLUSIONS

Both balloon sinuplasty and uncinectomy improved the quality of life and decreased upper airway resistance of patients with mild, isolated chronic or recurrent rhinosinusitis. The smaller risk of postoperative synechiae with balloon sinuplasty combined with its promising efficiency could partially compensate for its high material cost.

Anterior meatuscopy is more reliable than a sniff test for predicting nasal patency before transnasal endoscopy

BACKGROUND AND STUDY AIMS

Unsedated transnasal esophago-gastro-duodenoscopy (UT-EGD) has been performed for at least two decades but many techniques related to the procedure have yet to be standardized. We aimed to develope a simple endoscopic method, anterior meatuscopy, to replace the sniff test for selecting the most patent nasal meatus before UT-EGD. We hypothesized that access to the common nasal meatus (CNM), if confirmed by anterior meatuscopy, was a safer route than the inferior (INM) and middle nasal meatuses (MNM) because it would result in reduced epistaxis, nasal pain, and nasal discharge.

PATIENTS AND METHODS

We used anterior meatuscopy and an endoscopic meatus scoring scale (EMSS) to identify the optimal meatus for insertion. We evaluated the EMSS frequency distributions for the INM, CNM, and MNM and the reliability of a sniff test in 1,000 consecutive patients. The adverse effects of passing through the CNM versus the INM and MNM, respectively, were compared.

RESULTS

In the INM and MNM, the EMSS frequencies were grade I > II > III > 0 whereas those in the CNM were grade II > I > 0 > III. A sniff test was not reliable, given its low sensitivity (63.3 %), specificity (67.3 %), positive predictive value (69.1 %), negative predictive value (61.4 %), and accuracy (65.2 %). Although only 9.2 % of our patients had grade III anterior-to-posterior CNMs, passage through this spacious CNM rather than through the MNM or the INM could significantly reduce epistaxis, nasal pain, and nasal discharge.

CONCLUSIONS

Anterior meatuscopy is more reliable than a sniff test before UT-EGD. Transnasal endoscopic passage through the endoscopically patent CNM, if detected by anterior meatuscopy, may prevent epistaxis and nasal pain and minimize nasal discharge.

Thiamine and magnesium deficiencies: keys to disease

Thiamine deficiency (TD) is accepted as the cause of beriberi because of its action in the metabolism of simple carbohydrates, mainly as the rate limiting cofactor for the dehydrogenases of pyruvate and alpha-ketoglutarate, both being critical to the action of the citric acid cycle. Transketolase, dependent on thiamine and magnesium, occurs twice in the oxidative pentose pathway, important in production of reducing equivalents. Thiamine is also a cofactor in the dehydrogenase complex in the degradation of the branched chain amino acids, leucine, isoleucine and valine. In spite of these well accepted facts, the overall clinical effects of TD are still poorly understood. Because of the discovery of 2-hydroxyacyl-CoA lyase (HACL1) as the first peroxisomal enzyme in mammals found to be dependent on thiamine pyrophosphate (TPP) and the ability of thiamine to bind with prion protein, these factors should improve our clinical approach to TD. HACL1 has two important roles in alpha oxidation, the degradation of phytanic acid and shortening of 2-hydroxy long-chain fatty acids so that they can be degraded further by beta oxidation. The downstream effects of a lack of efficiency in this enzyme would be expected to be critical in normal brain metabolism. Although TD has been shown experimentally to produce reversible damage to mitochondria and there are many other causes of mitochondrial dysfunction, finding TD as the potential biochemical lesion would help in differential diagnosis. Stresses imposed by infection, head injury or inoculation can initiate intermittent cerebellar ataxia in thiamine deficiency/dependency. Medication or vaccine reactions appear to be more easily initiated in the more intelligent individuals when asymptomatic marginal malnutrition exists. Erythrocyte transketolase testing has shown that thiamine deficiency is widespread. It is hypothesized that the massive consumption of empty calories, particularly those derived from carbohydrate and fat, results in a high calorie/thiamine ratio as a major cause of disease. Because mild to moderate TD results in pseudo hypoxia in the limbic system and brainstem, emotional and stress reflexes of the autonomic nervous system are stimulated and exaggerated, producing symptoms often diagnosed as psychosomatic disease. If the biochemical lesion is recognized at this stage, the symptoms are easily reversible. If not, and the malnutrition continues, neurodegeneration follows and results in a variety of chronic brain diseases. Results from acceptance of the hypothesis could be tested by performing erythrocyte transketolase tests to pick out those with TD and supplementing the affected individuals with the appropriate dietary supplements.

The physiological mechanism for sensing nasal airflow: a literature review

BACKGROUND

Nasal obstruction is a common otolaryngologic complaint, yet the mechanism of sensing airflow is not commonly understood. The objective of this work was to review current knowledge on the physiological mechanism for sensing nasal airflow.

METHODS

Current literature pertaining to nasal sensation to airflow was retrieved using PubMed and Google Scholar searches.

RESULTS

The primary physiological mechanism that produces the sensation of ample nasal airflow is activation of trigeminal cool thermoreceptors, specifically transient receptor potential melastatin family member 8 (TRPM8), by nasal mucosal cooling. The dynamic change in temperature is ultimately sensed. Nasal mucosal cooling is a result of conductive heat loss, driven by temperature gradient, and evaporative heat loss, driven by humidity gradient. The perception of ample nasal airflow is dependent on the overall nasal surface area stimulated by mucosal cooling, which is mainly governed by air flow patterns. Cool thermoreceptors in the nasal mucosa are connected to the respiratory centers and consequently can alter respiration patterns. Mechanoreceptors do not seem to play a role in sensing nasal airflow. Computational fluid dynamics (CFD) modeling could be a valuable objective tool in evaluating patients with nasal congestion.

CONCLUSION

Understanding the physiological mechanism of how the nose senses airflow can aid in diagnosing the cause behind patient symptoms, which allows physicians to provide better treatment options for patients.

Spectral Estimation of Nasal Cyclic Rhythm by Nasal Airflow Temperature Measurement

.The nasal cycle is referred to a cyclic fluctuation in congestion of the nasal mucosa that results in rhythmic and bilateral reciprocal alteration of nasal airway patency. The purpose of this study is to deal with statistical and power spectral analysis of nasal cycle by measuring the temperature difference between the airflow of both left and right nostrils. Five adult voluntary healthy subjects are enrolled for the study. Nasal temperature probe combined with amplifier are used for recording nasal airflow temperature on both nostrils. The highest nasal airflow temperature values are detected at the end of expiration and the lowest values are detected at the end of inspiration. Nasal cycle found in all the subjects and lasted to the minimum of 30 minutes to maximum of 6 hours. The difference in temperature of both nostrils is statistically significant (p<0.05) and spectral estimation is made using autoregressive modeling. The method is used to quantify nasal obstruction in pathological condition and also to correlate the related physiological phenomenon.

An effective manual deboning method to prepare intact mouse nasal tissue with preserved anatomical organization

The mammalian nose is a multi-functional organ with intricate internal structures. The nasal cavity is lined with various epithelia such as olfactory, respiratory, and squamous epithelia which differ markedly in anatomical locations, morphology, and functions. In adult mice, the nose is covered with various skull bones, limiting experimental access to internal structures, especially those in the posterior such as the main olfactory epithelium (MOE). Here we describe an effective method for obtaining almost the entire and intact nasal tissues with preserved anatomical organization. Using surgical tools under a dissecting microscope, we sequentially remove the skull bones surrounding the nasal tissue. This procedure can be performed on both paraformaldehyde-fixed and freshly dissected, skinned mouse heads. The entire deboning procedure takes about 20-30 min, which is significantly shorter than the experimental time required for conventional chemical-based decalcification. In addition, we present an easy method to remove air bubbles trapped between turbinates, which is critical for obtaining intact thin horizontal or coronal or sagittal sections from the nasal tissue preparation. Nasal tissue prepared using our method can be used for whole mount observation of the entire epithelia, as well as morphological, immunocytochemical, RNA in situ hybridization, and physiological studies, especially in studies where region-specific examination and comparison are of interest.

Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat

Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%), and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%), naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO₂.

313 Psychogenic Intractable Sneezing. Case Report

Background

Sneezing is a coordinated protective respiratory reflex which occurs due to stimulation of the upper respiratory tract, and frequently accompanies allergic or nonallergic rhinitis. Sneezing can also arise due to bright light or sun (ACHOO syndrome), physical stimulants of the trigeminal nerve, psychogenic or central nervous system pathologies, sexual ideation and psychogenic sneezing. There are few case reports in the literature of patients with psychogenic sneezing.

Methods

14-year-old girl who had incessant sneezing for over 4 days. The patient was initially seen in a rural hospital, were it was prescribed prednisone and antihistamines but the patient did not show any improvement. She was refered to 3rd level Hospital and treated with nasal steroids, antihistamines, and isotonic sodium chloride solution nasal spray; sneezing remitted in 2 hours. During a follow up visit nasal endoscopy was normal. Had a similar episode a month after that, and was referred to our service. She didn´t have either personal or family history of allergies.

Results

There were not abnormalities in physical examination but obesity; nasal cytology and skin tests to aeroallergens were negatives. Received the same management with isotonic sodium chloride solution nasal and the symptoms remitted. Consultation with psychiatry is requested by probable psychogenic sneezing. The interrogation relates to the loss of father 3 years also suffered from bullying for obesity. Combined treatment was initiated by psychiatry and psychology.

Conclusions

Psychogenic Sneezing is a rare disorder, but should be considered in the differential diagnosis of sneezing. May have suspect if inspiratory phase is quite short and the amount of nasal mucosal secretion expelled very low. Eyes may remain open during sneezing. It usually develops due to psychogenic factors and is refractory to medical treatment. It is important to assess the patient in a holistic manner through a medical history and physical examination. Psychosocial environmental conditions should be investigated, and once identified the trigger requires a multidisciplinary treatment.

What are the primary clinical symptoms of rhinitis and what causes them?

The nose has a limited repertoire of responses regardless of the triggers. These responses primarily serve as a protective mechanism for the lower respiratory tract. Although the nasal reactions to pollens, particles, and pollution may have a beneficial effect for the lower airway, they create symptoms in some individuals that lead to significant morbidity. The symptoms of allergic rhinitis extend far beyond the nose, and the morbidity associated with rhinitis is significant. The nasal symptoms of rhinitis and their causes are the focus of this review.

Expression of functional TRPA1 receptor on human lung fibroblast and epithelial cells

The transient receptor potential subfamily A member 1 (TRPA1) is a non-selective cation channel implicated in the pathogenesis of several airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Most of the research on TRPA1 focuses on its expression and function in neuronal context; studies investigating non-neuronal expression of TRPA1 are lacking. In the present study, we show functional expression of TRPA1 in human lung fibroblast cells (CCD19-Lu) and human pulmonary alveolar epithelial cell line (A549). We demonstrate TRPA1 expression at both mRNA and protein levels in these cell types. TRPA1 selective agonists like allyl isothiocyanate (AITC), 4-hydroxynonenal (4-HNE), crotonaldehyde and zinc, induced a concentration-dependent increase in Ca+2 influx in CCD19-Lu and A549 cells. AITC-induced Ca+2 influx was inhibited by Ruthenium red (RR), a TRP channel pore blocker, and by GRC 17536, a TRPA1 specific antagonist. Furthermore, we also provide evidence that activation of the TRPA1 receptor by TRPA1 selective agonists promotes release of the chemokine IL-8 in CCD19-Lu and A549 cells. The IL-8 release in response to TRPA1 agonists was attenuated by TRPA1 selective antagonists. In conclusion, we demonstrate here for the first time that TRPA1 is functionally expressed in cultured human lung fibroblast cells (CCD19-Lu) and human alveolar epithelial cell line (A549) and may have a potential role in modulating release of this important chemokine in inflamed airways.

Pollen proteases compromise the airway epithelial barrier through degradation of transmembrane adhesion proteins and lung bioactive peptides

BACKGROUND

Allergic disorders, such as seasonal rhinitis and asthma, are increasing causes of morbidity worldwide and often result from exposure to airborne pollen. Pollen allergy has a remarkable clinical impact all over Europe. In fact, epidemiological longitudinal studies confirm that pollen species usually considered with low allergenic potential became more recently responsible for intense allergic reactions. In this study, we aimed to characterize major pollen proteolytic activity and evaluate its contribution to the immunologic and inflammatory response to airborne allergens.

METHODS

Proteolytic activity in four pollen diffusates with distinct allergenicity, Olea europaea, Dactylis glomerata, Cupressus sempervirens and Pinus sylvestris, was evaluated through several enzymatic assays. The action of pollen proteases on the paracellular integrity of Calu-3, grown at the air-liquid interphase, was evaluated through a transepithelial permeability assay. Immunoblot and immunofluorescence experiments were performed to analyse the disruption of intercellular complexes. Degradation of bioactive peptides by pollen crude extracts was assessed by mass spectrometry.

RESULTS

All pollen diffusates were shown to have high molecular weight proteases with serine and/or aminopeptidase activity. These proteases increased Calu-3 transepithelial permeability through disruption of transmembrane adhesion proteins: occludin, claudin-1 and E-cadherin. Moreover, they were able to degrade airway bioactive peptides and were not blocked by endogenous protease inhibitors.

CONCLUSION

Pollen grains with distinct allergenic abilities release proteases that might be involved in the sensitization to a range of airborne allergens by facilitating allergen delivery across the epithelium and also contribute directly to the inflammation characteristic of allergic diseases.

Physiology and pathophysiology of respiratory mucosa of the nose and the paranasal sinuses

In this review, anatomy and physiology of the respiratory mucosa of nose and paranasal sinuses are summarized under the aspect of its clinical significance. Basics of endonasal cleaning including mucociliary clearance and nasal reflexes, as well as defence mechanisms are explained. Physiological wound healing, aspects of endonasal topical medical therapy and typical diagnostic procedures to evaluate the respiratory functions are presented. Finally, the pathophysiologies of different subtypes of non-allergic rhinitis are outlined together with treatment recommendations.

Evaluation of optical rhinometry for nasal provocation testing in allergic and nonallergic subjects

OBJECTIVE: Optical rhinometry is a new method that quantifies light extinction in optical density to assess nasal blood volume as a measure of nasal patency. The purpose of this study is to evaluate optical rhinometry as an objective evaluation of nasal patency using nasal provocation testing with histamine and oxymetazoline.

STUDY DESIGN: Prospective pilot.

SETTING: Academic tertiary rhinologic practice.

SUBJECTS AND METHODS: Convenience sample of five adult subjects with allergic rhinitis and five adult normal subjects who underwent challenge with histamine and oxymetazoline. Patients underwent challenge with increasing concentrations of histamine to determine the amount of histamine needed to cause a positive optical rhinometry reading. The same subjects then underwent histamine challenge with this amount followed by oxymetazoline. Nasal patency was assessed subjectively after each challenge with the visual analog scale.

RESULTS: The median histamine amount needed to cause a positive response was statistically lower in allergic rhinitis as compared with nonallergic subjects at 150 μg and 300 μg, respectively ( P = 0.04). When comparing the optical rhinometry with subjective nasal congestion after histamine and oxymetazoline challenges, there was a statistically significant correlation with r = 0.79 ( P = 0.00003).

CONCLUSION: This initial study demonstrates a correlation between subjective symptoms of nasal patency and objective measurements with the optical rhinometer. Less histamine amount necessary to incite nasal congestion in allergic rhinitis suggests that these patients may be primed to the effects of histamine. These preliminary data suggest that optical rhinometry is able to assess changes in nasal patency during challenges with histamine and oxymetazoline.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Diagnostic strategies in nasal congestion

Nasal congestion is a major symptom of upper respiratory tract disorders, and its characterization an important part of the diagnosis of these illnesses. Patient history and assessment of nasal symptoms are essential components of diagnosis, providing an initial evaluation that may be adequate to rule out serious conditions. However, current congestion medications are not always fully effective. Thus, if symptoms do not respond adequately to therapy, or symptoms suggestive of more serious conditions are present, specialized assessments may be needed. Various techniques are available for diagnosing patients, including those used chiefly by primary care clinicians and those requiring the expertise of otolaryngologists, allergists, and other specialists. Endoscopy remains a mainstay for evaluating nasal blockage and its causes, while modalities such as peak nasal inspiratory flow and acoustic rhinometry are evolving to provide easy-to-use, noninvasive procedures that are sensitive enough to measure small but clinically important abnormalities and therapeutic changes. Several imaging modalities are available to the specialist for severe or unusual cases, as are specialized diagnostic procedures that measure adjunctive features of congestion, such as impaired mucociliary function.

The diffuse chemosensory system: exploring the iceberg toward the definition of functional roles

The diffuse chemosensory system (DCS) is an anatomical structure composed of solitary chemosensory cells (SCCs, also called solitary chemoreceptor cells), which have analogies with taste cells but are not aggregated in buds. The concept of DCS has been advanced, after the discovery that cells similar to gustatory elements are present in several organs. The elements forming the DCS share common morphological and biochemical characteristics with the taste cells located in taste buds of the oro-pharyngeal cavity but they are localized in internal organs. In particular, they may express molecules of the chemoreceptorial cascade (e.g. trans-membrane taste receptors, the G-protein alpha-gustducin, PLCbeta2, TRPM5). This article will focus on the mammalian DCS in apparatuses of endodermic origin (i.e. digestive and respiratory systems), which is composed of an enormous number of sensory elements and presents a multiplicity of morphological aspects. Recent research has provided an adequate description of these elements, but the functional role for the DCS in these apparatuses is unknown. The initial findings led to the definition of a DCS structured like an iceberg, with a mysterious "submerged" portion localized in the distal part of endodermic apparatuses. Recent work has focussed on the discovery of this submerged portion, which now appears less puzzling. However, the functional roles of the different cytotypes belonging to the DCS are not well known. Recent studies linked chemosensation of the intraluminal content to local control of absorptive and secretory (exocrine and endocrine) processes. Control of the microbial population and detection of irritants seem to be other possible functions of the DCS. In the light of these new findings, the DCS might be thought to be involved in a wide range of diseases of both the respiratory (e.g. asthma, chronic obstructive pulmonary disease, cystic fibrosis) and digestive apparatuses (absorptive or secretive diseases, dysmicrobism), as well as in systemic diseases (e.g. obesity, diabetes). A description of the functional roles of the DCS might be a first step toward the discovery of therapeutic approaches which target chemosensory mechanisms.

Airborne transmission of disease in hospitals

Hospital-acquired infection (HAI) is an important public health issue with unacceptable levels of morbidity and mortality, over the last 5 years. Disease can be transmitted by air (over large distances), by direct/indirect contact or a combination of both routes. While contact transmission of disease forms the majority of HAI cases, transmission through the air is harder to control, but one where the engineering sciences can play an important role in limiting the spread. This forms the focus of this themed volume. In this paper, we describe the current hospital environment and review the contributions from microbiologists, mechanical and civil engineers, and mathematicians to this themed volume on the airborne transmission of infection in hospitals. The review also points out some of the outstanding scientific questions and possible approaches to mitigating transmission.

A review of the efficacy of desloratadine, fexofenadine, and levocetirizine in the treatment of nasal congestion in patients with allergic rhinitis

BACKGROUND

Nasal congestion is the most troublesome symptom of allergic rhinitis (AR). First-generation and older second-generation antihistamines, while effective against nasal itching, sneezing, and rhinorrhea, have limited efficacy in relieving nasal congestion.

OBJECTIVE

This review included nasal challenge studies and clinical trials that reported the effects on nasal congestion of the newer second-generation antihistamines desloratadine, fexofenadine, and levocetirizine.

METHODS

MEDLINE and EMBASE were searched for nasal challenge studies and clinical trials published in English between January 1, 1991, and January 31, 2009, using the following terms, alone or in combination: antihistamines, second-generation antihistamines, allergic rhinitis, intermittent allergic rhinitis, perennial allergic rhinitis, persistent allergic rhinitis, seasonal allergic rhinitis, nasal challenge, nasal blockage, and nasal congestion. Studies that were not active or placebo controlled, that did not evaluate change in nasal congestion scores, or that focused on treatments other than desloratadine, fexofenadine, and levocetirizine for nasal congestion associated with AR were excluded.

RESULTS

Twenty-six clinical trials met the criteria for inclusion in the review. In 11 placebo-controlled trials that included objective assessment of nasal congestion, desloratadine, fexofenadine, and levocetirizine were associated with reductions in the severity of nasal congestion through maintenance of nasal airflow. The mean AUC for nasal airflow over 6 hours was significantly greater with desloratadine compared with placebo in 3 studies (P < 0.05); placebo-controlled trials of fexofenadine and levocetirizine had similar results. In 25 placebo- and active-controlled trials that reported subject-rated symptom scores, the 3 newer antihistamines were efficacious in the treatment of nasal congestion associated with AR. In 10 trials that reported objective and/or subjective measures, desloratadine was associated with significant improvements in nasal congestion compared with placebo (P < or = 0.05), beginning as early as the first 2 hours after allergen challenge. Fexofenadine was associated with significantly lower nasal congestion scores compared with placebo in 4 studies (P <- 0.05); nasal congestion scores were significantly reduced with levocetirizine in 3 placebo-controlled trials (P < or = 0.005).

CONCLUSIONS

In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.

Breathtaking TRP channels: TRPA1 and TRPV1 in airway chemosensation and reflex control

New studies have revealed an essential role for TRPA1, a sensory neuronal TRP ion channel, in airway chemosensation and inflammation. TRPA1 is activated by chlorine, reactive oxygen species, and noxious constituents of smoke and smog, initiating irritation and airway reflex responses. Together with TRPV1, the capsaicin receptor, TRPA1 may contribute to chemical hypersensitivity, chronic cough, and airway inflammation in asthma, COPD, and reactive airway dysfunction syndrome.