Aggregated eosinophils and neutrophils characterize the properties of mucus in chronic rhinosinusitis.

BACKGROUND: Airway obstruction caused by viscous mucus is an important pathophysiologic characteristic of persistent inflammation, which can result in organ damage. OBJECTIVE: We investigated the hypothesis that the biophysical characteristics of accumulating granulocytes affect the clinical properties of mucus. METHODS: Surgically acquired nasal mucus samples from patients with eosinophilic chronic rhinosinusitis and neutrophil-dominant, noneosinophilic chronic rhinosinusitis were evaluated in terms of computed tomography density, viscosity, water content, wettability, and protein composition. Isolated human eosinophils and neutrophils were stimulated to induce the formation of extracellular traps, followed by the formation of aggregates. The biophysical properties of the aggregated cells were also examined. RESULTS: Mucus from patients with eosinophilic chronic rhinosinusitis had significantly higher computed tomography density, viscosity, dry weight, and hydrophobicity compared to mucus from patients with noneosinophilic chronic rhinosinusitis. The levels of eosinophil-specific proteins in mucus correlated with its physical properties. Eosinophil and neutrophil aggregates showed physical and pathologic characteristics resembling those of mucus. Cotreatment with deoxyribonuclease and heparin, which slenderizes the structure of eosinophil extracellular traps, efficiently induced reductions in the viscosity and hydrophobicity of both eosinophil aggregates and eosinophilic mucus. CONCLUSIONS: The present study elucidated the pathogenesis of mucus stasis in infiltrated granulocyte aggregates from a novel perspective. These findings may contribute to the development of treatment strategies for eosinophilic airway diseases.

Retinoic acid promotes fibrinolysis and may regulate polyp formation.

BACKGROUND: Patients with aspirin-exacerbated respiratory disease (AERD) regularly exhibit severe nasal polyposis. Studies suggest that chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by excessive fibrin deposition associated with a profound decrease in epithelial tissue plasminogen activator (tPA). Retinoids, including vitamin A and its active metabolite retinoic acid (RA), are necessary for maintaining epithelial function and well-known inducers of tPA in endothelial cells. OBJECTIVES: This study sought to determine whether endogenous retinoids are involved in NP pathophysiology and disease severity in patients with CRSwNP and AERD. METHODS: NP tissue was collected from patients with AERD or CRSwNP, and concentrations of retinoids and fibrinolysis markers were measured using ELISA. Normal human bronchial epithelial cells were stimulated alone or in combination with RA and IL-13 for 24 hours. RESULTS: This study observed lower retinoid levels in nasal polyps of patients with AERD than those with CRSwNP or healthy controls (P < .01). Levels of the fibrin-breakdown product d-dimer were the lowest in AERD polyps (P < .01), which is consistent with lower tPA expression (P < .01). In vitro, all-trans RA upregulated tPA levels in normal human bronchial epithelial cells by 15-fold and reversed the IL-13-induced attenuation of tPA expression in cultured cells (P < .01). CONCLUSIONS: RA, a potent inducer of epithelial tPA in vitro, is reduced in tissue from patients with AERD, a finding that may potentially contribute to decreased levels of tPA and fibrinolysis in AERD. RA can induce tPA in epithelial cells and can reverse IL-13-induced tPA suppression in vitro, suggesting the potential utility of RA in treating patients with CRSwNP and/or AERD.

Dupilumab improves eosinophilic otitis media associated with eosinophilic chronic rhinosinusitis.

BACKGROUND: Eosinophilic otitis media (EOM) is a refractory condition associated with eosinophilic chronic rhinosinusitis and bronchial asthma. EOM is characterized by type-2 inflammation and is refractory to various treatments. We investigated the efficacy of dupilumab, interleukin-4 receptor alpha antagonist, for patients with EOM complicated by eosinophilic chronic rhinosinusitis (ECRS). METHODS: Between April 2017 and April 2022, we treated 124 patients with dupilumab for refractory CRS or bronchial asthma. Of these, 14 had EOM concurrently, and 10 of them who had been treated for >6 months were included in our study. We retrospectively evaluated the efficacy of dupilumab by the amount of systemic corticosteroid used, the frequency of exacerbations, severity score of EOM, computed tomography (CT) score of temporal bones, and pure tone audiometry. We also enrolled 8 EOM patients without dupilumab treatment as a control group. RESULTS: Dupilumab significantly improved the amount of systemic corticosteroid used and the frequency of exacerbation and compared with before dupilumab was used (p = 0.01 and <0.01, respectively). All patients could be weaned from systemic-corticosteroid therapy by 54 weeks of dupilumab use. The severity score of EOM and CT score for temporal bones were significantly lower than before the treatment (p = 0.01 and 0.01, respectively). Compared to the control group, the systemic corticosteroid used and severity scores were improved in the dupilumab group (p = 0.02 and < 0.01, respectively). CONCLUSIONS: Dupilumab could be used to wean patients from systemic corticosteroids with the improvement of severity score in EOM associated with ECRS and bronchial asthma.

Real-life effectiveness of dupilumab in patients with mild to moderate bronchial asthma comorbid with CRSwNP.

BACKGROUND: Dupilumab, an anti-IL-4α receptor antibody, is a new treatment for severe or refractory asthma. However, real-world evidence on the efficacy of dupilumab in patients with mild to moderate bronchial asthma is lacking. METHODS: We retrospectively evaluated the effects of dupilumab in 62 patients who received dupilumab for eosinophilic sinusitis comorbid with asthma at a single centre in Japan. Type 2 inflammatory markers, ACT, respiratory function tests, and forced oscillation technique (FOT) were analysed before, three months after, and one year after dupilumab administration, mainly in patients with mild to moderate asthma. RESULTS: FEV1, %FEV1, %FVC, treatment steps for asthma and ACT improved significantly after three months of dupilumab treatment. FeNO was markedly decreased, whereas IgE and eosinophil counts showed no significant changes. Pre- and post-treatment respiratory resistance (Rrs) and respiratory reactance (Xrs) correlated significantly with FEV1. Improvement in %FEV1 was associated with higher FeNO and higher serum IgE before dupilumab treatment. CONCLUSION: Dupilumab treatment for sinusitis may improve respiratory functions, asthma symptoms, and asthma treatment reduction, even if the associated bronchial asthma is not severe.

Eosinophil extracellular trap cell death-derived DNA traps: Their presence in secretions and functional attributes.

BACKGROUND: Activated human eosinophils, as well as neutrophils, can release extracellular chromatin to form DNA traps through cytolytic extracellular trap cell death (ETosis). Although formations of neutrophil DNA traps are recognized in patients with various inflammatory conditions, neither the presence of ETosis-derived eosinophil DNA traps in human allergic diseases nor the characteristics of these DNA traps have been studied. OBJECTIVE: We investigated the presence of ETosis-derived DNA traps in eosinophil-rich sinus and ear secretions and the functional attributes of ETosis DNA traps. METHODS: Eosinophil-rich secretions obtained from patients with eosinophilic chronic rhinosinusitis and eosinophilic otitis media were studied microscopically. In vitro studies of ETosis and DNA trap formation used blood-derived eosinophils and neutrophils, and studies of the binding capacities of DNA traps used labeled bacteria and fluorescent microbeads. Stabilities of DNA traps were evaluated by using fluorescence microscopy. RESULTS: Abundant nuclear histone H1-bearing DNA traps formed in vivo in the eosinophilic secretions and contributed to their increased viscosity. In vitro, after brief shear flow, eosinophil ETosis-elicited DNA traps assembled to form stable aggregates. Eosinophil DNA traps entrapped bacteria and fungi and, through hydrophobic interactions, microbeads. In comparison with neutrophil-derived DNA traps, eosinophil DNA traps ultrastructurally exhibited thicker fibers with globular structures and were less susceptible to leukocyte-derived proteolytic degradation, likely because of the lesser protease activities of eosinophils. CONCLUSIONS: In human allergic diseases local cytolysis of eosinophils not only releases free eosinophil granules but also generates nuclear-derived DNA traps that are major extracellular structural components within eosinophil-rich secretions.

The administration of nasal drops in the "Kaiteki" position allows for delivery of the drug to the olfactory cleft: a pilot study in healthy subjects.

Systemic treatment with corticosteroids shows therapeutic effects, few patients benefit from intranasal topical drug application, probably due to limited access of the drug to the olfactory epithelium. The aim of the present study was to investigate how drops distribute within the nasal cavity when the "Kaiteki" position is performed. Thirteen healthy volunteers participated. Subjects were lying on the side with the head tilted and the chin turned upward. Blue liquid was used to visualize the intranasal distribution of the nasal drops. The investigation was carried out using photo documentation thorough nasal endoscopy; the intranasal distribution of the dye was judged by two independent observers in both a decongested state and a natural state where no decongestants had been used. With regard to the main criterion of this study, using the "Kaiteki" position, nasal drops reached the olfactory cleft in 96 % of the decongested cases and 75 % of the cases who had not been decongested. However, this difference was not statistically different. Because the "Kaiteki" maneuver is not too difficult to perform, it is more likely that topical steroids can be helpful in cases of olfactory loss.

Eosinophil-derived neurotoxin, elastase, and cytokine profile in effusion from eosinophilic otitis media.

BACKGROUND: Eosinophilic otitis media (EOM) is an intractable disease characterized by a remarkably viscous effusion and accumulation of numerous eosinophils in both the middle ear effusion and the mucosa. The key factors in EOM pathogenesis remain unclear. The purpose of this study is to identify the important factors involved in EOM pathogenesis. METHODS: Middle ear effusion samples were collected from 12 patients with EOM and 9 patients with secretory otitis media (SOM), as controls. Multiple cytokines in the effusion were measured using a Bio-Plex™ Human Cytokine 27-Plex panel. Eosinophil-derived neurotoxin (EDN) and elastase were measured by ELISA. The concentrations of EDN, elastase, and each cytokine were compared between the EOM and SOM groups. Furthermore, in the EOM group, each cytokine was examined for correlation with EDN and elastase. RESULTS: EDN and elastase concentrations were significantly higher in the EOM group than in the SOM group (p < 0.05). IL-5, IL-1ß, MIP-1α, G-CSF, IL-1ra, IL-4, IFN-γ, MIP-1ß, IL-10, TNF-α, VEGF, and IL-2 concentration was significantly higher in the EOM group than in the SOM group (p < 0.05). Significant positive correlations were found between EDN and IL-1ra, IL-2, IL-5, IL-9, IL-13, eotaxin, MIP-1α, PDGF-BB, and RANTES in the EOM group (p < 0.05). CONCLUSIONS: Our study showed that IL-5, IL-2, MIP-1α, and IL-1ra are the important factors involved in EOM pathogenesis. Furthermore, not only eosinophil, but also neutrophil are involved in middle ear inflammation of EOM.

Efficacy of tokishakuyakusan and mecobalamin on post-infectious olfactory dysfunction: A prospective multicenter study.

OBJECTIVE: To determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B12 (mecobalamin). METHODS: We conducted a randomized, nonblinded clinical trial. Patients with PIOD enrolled in 17 hospitals and clinics from 2016 to 2020 were randomly divided into two groups, and we administered TSS or mecobalamin for 24 weeks. Their olfactory function was examined using interviews and T&T olfactometry. The improvement of olfactory dysfunction was assessed following the criteria of the Japanese Rhinologic Society. RESULTS: Overall, 82 patients with PIOD were enrolled in this study. In the TSS and mecobalamin groups, 39 patients completed the medication regimen. In the TSS and mecobalamin groups, olfactory dysfunction was significantly improved based on self-reports and olfactory test results. The improvement rate of olfactory dysfunction was 56% in the TSS group and 59% in the mecobalamin group. Early intervention within 3 months produced a better prognosis than the treatment initiated after 4 months. Furthermore, age and sex differences were not observed. Both medications produced no severe adverse events. CONCLUSION: The present study showed that TSS and mecobalamin might be useful for treating PIOD.

Alternaria inhibits double-stranded RNA-induced cytokine production through Toll-like receptor 3.

BACKGROUND: Fungi may be involved in asthma and chronic rhinosinusitis (CRS). Peripheral blood mononuclear cells from CRS patients produce interleukin (IL)-5, IL-13 and interferon (IFN)-γ in the presence of Alternaria. In addition, Alternaria produces potent Th2-like adjuvant effects in the airway. Therefore, we hypothesized that Alternaria may inhibit Th1-type defense mechanisms against virus infection. METHODS: Dendritic cells (DCs) were generated from mouse bone marrow. The functional responses were assessed by expression of cell surface molecules by FACS (MHC class II, CD40, CD80, CD86 and OX40L). Production of IL-6, chemokine CXCL10 (IP-10), chemokine CXCL11 (I-TAC) and IFN-ß was measured by ELISA. Toll-like receptor 3 (TLR3) mRNA and protein expression was detected by quantitative real-time PCR and Western blot. RESULTS: Alternaria and polyinosinic-polycytidylic acid (poly I:C) enhanced cell surface expression of MHC class II, CD40, CD80, CD86 and OX40L, and IL-6 production in a concentration-dependent manner. However, Alternaria significantly inhibited production of IP-10, I-TAC and IFN-ß, induced by viral double-stranded RNA (dsRNA) mimic poly I:C. TLR3 mRNA expression and protein production by poly I:C were significantly inhibited by Alternaria. These reactions are likely caused by heat-stable factor(s) in Alternaria extract with >100 kDa molecular mass. CONCLUSION: These findings suggest that the fungus Alternaria may inhibit production of IFN-ß and other cytokines by DCs by suppressing TLR3 expression. These results indicate that Alternaria may inhibit host innate immunity against virus infection.

The expression of protease-activated receptors in chronic rhinosinusitis.

BACKGROUND: A recent study suggested that protease-activated receptors (PARs) are involved in allergic respiratory diseases, such as asthma. Chronic rhinosinusitis (CRS) is one of the most common chronic airway diseases, but little is understood about its pathogenesis. The purpose of this study was to compare the expression and distribution of PARs in biopsy specimens obtained from CRS and control patients. METHODS: Biopsy specimens were obtained from 7 pituitary tumor patients as controls, 8 CRS patients with aspirin-tolerant asthma (ATA), 7 CRS patients with aspirin-induced asthma (AIA), and 7 CRS patients without asthma (CRS). Sections were stained for PAR-1, PAR-2, PAR-3 and PAR-4 using specific polyclonal antibodies. Staining was scored semiquantitatively for both intensity and distribution. To confirm the presence of PARs on inflammatory cells, double staining with eosinophil cationic protein (EG2) and elastase was also performed. RESULTS: Both the epithelium and the infiltrating inflammatory cells in the CRS with asthma groups showed significant upregulation of the expression of PAR-2 and PAR-3 compared with the CRS without asthma group and the control group. In the patients with CRS complicated by asthma, eosinophils were increased among PAR-2- and PAR-3-positive cells. In the patients with CRS not complicated by asthma, neutrophils were increased among PAR-2-positive cells. CONCLUSIONS: Differences in the expression of PAR-2 and PAR-3 on epithelial cells, eosinophils and neutrophils may be involved in the pathogenesis of CRS. CRS may be able to be treated by targeting PAR-2 and PAR-3.

Total and antigen- (fungi, mites and staphylococcal enterotoxins) specific IgEs in nasal polyps is related to local eosinophilic inflammation.

BACKGROUND: Total and specific immunoglobulin E (IgE) in nasal polyps (NP) is related to local eosinophilic inflammation. However, it remains unclear which antigens cause a stronger accumulation of eosinophils in NP. We investigated whether local IgEs to specific antigens correlated with local eosinophil accumulation. METHODS: Total IgE, antigen-specific IgEs [5 species of fungi, staphylococcal enterotoxins A and B (SEA and SEB), cedar pollen, ragweed pollen and house-dust mites] and eosinophil cationic protein (ECP) were measured in sinus mucosa homogenates and serum from 29 patients with chronic rhinosinusitis with NP (CRSwNP), 8 patients with allergic fungal rhinosinusitis (AFRS) and 8 control subjects without CRS. The level of ECP in NP was analyzed for correlations with the total and specific IgE levels in the serum and NP. RESULTS: In CRSwNP, antigen-specific IgEs [Alternaria > mite (Dp) > Aspergillus > SEB > Penicillium > mite (Df), but not the other fungi, SEA or pollens] in the sinus mucosa correlated significantly with the local ECP. In AFRS, antigen-specific IgEs [Penicillium > mite (Df) > Alternaria, but not the other fungi, SEs or pollens] in the sinus mucosa correlated significantly with the local ECP. CONCLUSIONS: Local total IgE and antigen (fungi, mites and SEs)-specific IgEs in NP are related to the local eosinophilic inflammation of AFRS and CRSwNP.

Shielding device for endoscopic procedures during lower gastrointestinal endoscopy.

Objectives: The coronavirus pandemic significantly impacted endoscopic practice. During lower gastrointestinal endoscopy, infectious substances disseminate; therefore, we developed an infection control device (STEP-L) for lower gastrointestinal endoscopy and examined its usefulness. Methods: STEP-L wraps around the patient's buttocks and covers the endoscope. Using lower endoscopy training models, three endoscopists performed 18 colonoscopies with STEP-L (group S) and without (group C). Endoscopic insertion time and pigmented areas of ​​gloves and diapers after the examination were compared between both groups. Results: Insertion of the endoscope up to the cecum was possible in all 18 examinations. The insertion time to the cecum was 52.4 ± 19.0 s in group S and 53.9 ± 13.3 s in group C. The pigmented areas of the ​​gloves measured 39,108.0 ± 16,155.3 pixels in group C, but were significantly reduced to 2610.5 ± 4333.8 pixels in group S (p < 0.05). The pigmented areas of the diapers measured 2280.9 ± 3285.2 pixels in group C, but were significantly reduced to 138.0 ± 82.9 pixels in group S (p < 0.05). Conclusions: Using STEP-L does not change the insertion time, and is technically feasible. STEP-L significantly reduces the adhesion of virtual pollutants to the surroundings, suggesting that this device is useful for infection control during lower gastrointestinal endoscopy.

Barrier Factors of Adherence to Dupilumab Self-Injection for Severe Allergic Disease: A Non-Interventional Open-Label Study.

Purpose: The status of dupilumab self-injection at home is not well understood. We therefore aimed to identify the barriers to adherence to dupilumab self-injection. Patients and Methods: This non-interventional open-label study was conducted between March 2021 and July 2021. Patients with atopic dermatitis, bronchial asthma, and chronic rhinosinusitis with nasal polyps receiving dupilumab, from 15 sites, were requested to complete a self-administered questionnaire regarding the frequency and effectiveness of dosing as well as their use and satisfaction with dupilumab. Barriers to adherence were assessed using the Adherence Starts with Knowledge-12. Results: We included 331 patients who used dupilumab for atopic dermatitis (n = 164), chronic rhinosinusitis with nasal polyps (n = 102), and bronchial asthma (n = 65). The median efficacy of dupilumab scored 9.3 on the visual analog scale. Overall, 85.5% of the patients self-injected dupilumab, and 70.7% perfectly complied with the established injection dates. The pre-filled pen was significantly superior to the conventional syringe in terms of usability, operability, ease of pushing the plunger, and patient satisfaction. However, the pre-filled pen caused more pain during self-injection than did the syringe. Multivariate logistic regression analysis showed that adherence decreased with longer dupilumab treatment duration (p = 0.017) and was not associated with age, sex, underlying disease, or device type. There was a difference in responses related to "inconvenience/forgetfulness" between the good and poor adherence groups. Conclusion: The pre-filled dupilumab pen was superior to the syringe in terms of usability, operability, ease of pushing the plunger, and satisfaction. Repetitive instructions are recommended for preventing poor adherence to dupilumab self-injection.

Alternaria fungus induces the production of GM-CSF, interleukin-6 and interleukin-8 and calcium signaling in human airway epithelium through protease-activated receptor 2.

RATIONALE: Recent studies suggest that host immune responses to environmental fungi may play an important role in the development of allergic diseases, such as human asthma. Epithelium is considered an active participant in allergic inflammation. We previously reported that aspartate protease from Alternaria induces the activation and degranulation of human eosinophils that are mediated through protease-activated receptor 2 (PAR-2). However, our current knowledge on the innate immune responses of epithelium to environmental fungi is very limited. We investigated the responses of epithelium to fungi and the mechanisms of these responses. METHODS: Human airway epithelial cell line BEAS-2B and Calu-3 (both from American Type Culture Collection) were incubated with PAR-2 peptides and extracts of various fungi. The cellular responses, including GM-CSF, interleukin (IL)-6, IL-8, eotaxin, eotaxin-2 and RANTES production as well as increases in intracellular calcium concentration ([Ca(2+)](i)), were examined. To characterize the proteases involved in these responses, protease inhibitors such as pepstatin A and alkalo-thermophilic Bacillus inhibitor (ATBI), HIV protease inhibitors and 4-amidinophenylmethanesulfonyl fluoride hydrochloride were used. To investigate the role of PAR-2, PAR-2-agonistic and PAR-2-antagonistic peptides were used. RESULTS: PAR-2-activating peptide, but not the control peptide, induced GM-CSF, IL-6 and IL-8 production; these cellular responses were accompanied by a quick and marked increase in [Ca(2+)](i). Among 7 common environmental fungi, only Alternaria induced GM-CSF, IL-6 and IL-8 production and increased [Ca(2+)](i) response. Both cytokine production and increased [Ca(2+)](i) were significantly inhibited by PAR-2 antagonist peptide and by aspartate protease inhibitors (pepstatin A, ritonavir, nelfinavir and ATBI), but not by the PAR-2 control peptide or by other protease inhibitors. CONCLUSIONS: Aspartate proteases from Alternaria induce cytokine production and calcium response in airway epithelium that is mediated through PAR-2. This protease-mediated activation of airway epithelium may be implicated in the development and exacerbation of airway allergic disease.

[Evaluation of clinical features of antrochoanal polyps].

Current knowledge on the prevalence and clinical features of antrochoanal polyps (ACPs), benign lesions arising in the maxillary sinus and extending into the choana, is very limited in Japan. We prospectively evaluated prevalence and clinical features in 15 subjects with ACPs from among 728 undergoing endoscopic endonasal sinus surgery between April 2007 and March 2008, and prospectively enrolled in this study. The 15 subjects, who accounted for 2.1% of the total, had nasal obstruction, rhinorrhea, and postnasal drip. Symptoms significantly reduced postoperatively. Maxillary-sinus-origin ACP distribution was 40% from the maxillary sinus floor to the posterior wall, 26.7% from maxillary sinus floor, and 20% from the maxillary sinus floor to the internal wall. Postoperative recurrence was 13.3%. Endoscopic endonasal sinus surgery for ACPs was most effective for polyp is originating in the maxillary sinus determined carefully and excised as completely as possible, followed by appropriate postoperative treatment.

[Endoscopic sinus surgery complications a prospective multicenter study].

OBJECTIVE: Our objective was to determine the rate of complications in endoscopic sinus surgery (ESS) and associated risk factors. METHODS: We prospectively studied 1,382 subjects undergoing ESS for rhinosinusitis and cystic sinus disease at 16 hospitals during 2007 and 2008. Surgeons provided information on peri-and postoperative complication occurrence. RESULT: Results of complications were seen in 80 subjects (5.8%), the most frequent was perioperative lamina papyracea injury. Analysis showed the complication rate to be linked to gender, and anesthesia type, but not the grade of surgeon. CONCLUSIONS: While care should be taken to avoid them, complications should be identified and treated in a timely and accurate manner.

Development of protective equipment for endoscopic treatment and surgery in otorhinolaryngology.

OBJECTIVE: The coronavirus disease pandemic has raised concerns regarding the transmission of infections to healthcare workers. We developed a new protective device to reduce the risk of aerosol diffusion and droplet infection among healthcare workers. Here, we report the results of a theoretical evaluation of the efficacy of this device. METHODS: We used suction-capable masks with and without rubber slits, sleeves for the insertion section of endoscopes and treatment tools, and a cover for the control section of the endoscope. To simulate droplet spread from patients, we created a droplet simulation model and an aerosol simulation model. The results with and without the devices attached and with and without the suction were compared. RESULTS: The droplet simulation model showed a 95% reduction in droplets with masks with rubber slits; furthermore, a reduction of 100% was observed when the insertion sleeve was used. Evaluation of aerosol simulation when suction was applied revealed an aerosol reduction of 98% and >99% with the use of the mask without rubber slits and with the combined use of the mask and insertion sleeve, respectively. The elimination of droplet emission upon instrument removal confirmed that the instrument sleeve prevented the diffusion of droplets. The elimination of droplets upon repeated pressing of the suction button confirmed that the cover prevented the diffusion of droplets. CONCLUSION: We developed a device for infection control, in collaboration with a gastrointestinal endoscopist and Olympus Medical Systems Corporation, that was effective in reducing droplet and aerosol diffusion in this initial theoretical assessment.

MRI tractography reveals the human olfactory nerve map connecting the olfactory epithelium and olfactory bulb.

The olfactory nerve map describes the topographical neural connections between the olfactory epithelium in the nasal cavity and the olfactory bulb. Previous studies have constructed the olfactory nerve maps of rodents using histological analyses or transgenic animal models to investigate olfactory nerve pathways. However, the human olfactory nerve map remains unknown. Here, we demonstrate that high-field magnetic resonance imaging and diffusion tensor tractography can be used to visualize olfactory sensory neurons while maintaining their three-dimensional structures. This technique allowed us to evaluate the olfactory sensory neuron projections from the nasal cavities to the olfactory bulbs and visualize the olfactory nerve maps of humans, marmosets and mice. The olfactory nerve maps revealed that the dorsal-ventral and medial-lateral axes were preserved between the olfactory epithelium and olfactory bulb in all three species. Further development of this technique might allow it to be used clinically to facilitate the diagnosis of olfactory dysfunction.

Human eosinophil innate response to Alternaria fungus through protease-activated receptor-2.

Eosinophils are multifunctional leukocytes implicated in the pathogenesis of allergic diseases. An association between eosinophilic inflammation and infection or colonization by fungi has also been long recognized. However, the mechanisms underlying how eosinophils are activated and how they release proinflammatory and immunomodulatory mediators such as major basic protein (MBP) and eosinophil-derived neurotoxin remain largely unknown. We used a fungus, i.e. Alternaria, as a model microbe relevant to human asthma and chronic rhinosinusitis (CRS) to investigate the molecular mechanisms involved in the immune recognition of ubiquitous environmental allergens. Human eosinophils are activated by live Alternaria alternata organisms, release their granule proteins, and kill the fungi. Eosinophils, but not neutrophils, respond to secreted products from A. alternata. We found that eosinophils are equipped with innate cellular activation machinery that responds to an extracellular aspartate protease secreted by Alternaria. Aspartate protease activation of protease-activated receptor (PAR)-2 probably involves a novel mechanism different from that for serine protease activation of PAR-2. Thus, human eosinophils may recognize certain danger signals or virulence factors produced by fungi and provoke inflammatory responses against these organisms. Dysregulation of such an innate immune mechanism may be involved in the pathophysiology of certain human inflammatory diseases, including asthma and CRS.

Cockroach induces inflammatory responses through protease-dependent pathways.

Exposure to cockroaches is a major risk factor for asthma. Products from cockroaches may contain proteases and ligands for pattern recognition receptors. These molecules may activate airway inflammatory cells, such as eosinophils, that are involved in asthma. Among inner-city children, cockroach allergens play an especially important role in increasing asthma morbidity. The molecular mechanism for this association between cockroach exposure and asthma is not fully understood. Enzymatic activities from cockroaches activate inflammatory cells in the airways and may also exacerbate certain human airway diseases, such as asthma. We recently reported that cockroach extracts contain pepstatin A-sensitive proteases that activate PAR-2 and induce activation and degranulation of human eosinophils. This review focuses on the effects of cockroach on various inflammatory cells, including eosinophils, epithelial cells, fibroblasts, dendritic cells, and T cells, in allergic reactions.