Mast cells drive IgE-mediated disease but might be bystanders in many other inflammatory and neoplastic conditions.

Mast cells (MCs) are capable of executing powerful inflammatory response programs triggered by surface IgE cross-linking or through pattern recognition receptors. The question of how MCs contribute to human disease has been intensely investigated and stimulated much controversy. Correlative evidence comes from human studies, pointing to pathogenetic or protective MC functions in patients with atopic conditions, autoimmune disorders, type 2 diabetes, chronic urticaria, mastocytosis, and cancer. Experiments in MC-deficient mice underpinned key roles for MCs in patients with IgE-mediated allergic conditions. Important pathogenetic MC contributions to other inflammatory and neoplastic conditions were suggested by studies in traditional KIT mutant MC-deficient mouse strains. However, many of these findings were not reproduced in more recently developed improved mouse models of MC deficiency, largely ruling out roles for MCs in mouse models for autoimmune disease, diabetes, and cancer. We discuss limitations of studies in mice and human subjects and provide suggestions for how they can be overcome, such as through the development of specific and selective MC-targeted treatments.

Measurement of middle ear pressure changes during balloon eustachian tuboplasty: a pilot study.

CONCLUSION: The middle ear pressure changes detected during BET can be directly attributed to the balloon inflation and may represent a second, immediate, mechanism of action of BET. BET seems to be safe with respect to the risk of a barotrauma. Further human studies are now necessary to confirm the results and gain more insight into the mechanism of action of BET. OBJECTIVE: Since the introduction of Balloon Eustachian Tuboplasty (BET) as a treatment of chronic Eustachian tube dysfunction, the precise mechanism of action is unknown. Long-term effects of BET may be related to observed microfractures of the Eustachian tube cartilage. However, clinical observations indicate a second, immediate mode of action. Therefore, this study investigated and characterized middle ear pressure changes occurring directly during BET procedure. METHODS: Using a micro-optical pressure sensor, pressure changes during BET were monitored transtympanically in a cadaveric animal study using heathland sheep. RESULTS: Middle ear pressure amplitudes during BET are dependent on the speed of balloon inflation as well as the maximum inflation pressure. A 10-bar inflation pressure yielded a mean middle ear pressure of 5.34 mmHg (71.0 daPA). Negative pressure amplitudes occurring on withdrawal of the balloon catheter are influenced by the speed of withdrawal. No pressure amplitudes capable of causing barotrauma to membranous ear structures could be detected.

Mouse models of induced otitis media.

The mouse has seen limited use as a model for experimental otitis media, due primarily to the small size of its middle ear. However, the genetic resources of this species offer substantial potential benefits. These include detailed genomic information, a wealth of genetic models, and gene arrays that represent virtually all mouse genes. This has led to the development of methods for inducing otitis in mice. These include surgical approaches to the middle ear, documentation of the murine middle ear response to various pathogens and inflammatory factors, as well as characterization of induced otitis media in several mouse strains. The results indicate that induced otitis media in the normal mouse is in most respects comparable to that observed in other animal models and in humans. They further suggest that the considerable genetic resources of this species can be harnessed to increase our understanding of this disease.

A novel diagnostic tool for chronic obstructive eustachian tube dysfunction­the eustachian tube score.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to introduce a new tool for the diagnosis of chronic obstructive eustachian tube dysfunction (ETD) and as a follow-up tool for eustachian tube therapy using objective and subjective elements. STUDY DESIGN: Combined, prospective, retrospective clinical study at a tertiary referral center. METHODS: Physical examination, history, tympanometry, audiometry, and tubomanometry as well as the seven-item Eustachian Tube Dysfunction Questionnaire (EDTQ-7) were included as diagnostic tests. After initiating the eustachian tube score (ETS), we compared our results of healthy subjects to our data of patients with chronic obstructive ETD. In addition to ETS, an extended test ETS-7 was evaluated, which incorporated two additional items. RESULTS: The test-retest reliability revealed a correlation of 0.82 for the ETS and 0.87 for the ETS-7. ETS-7 receiver operating characteristic analysis, with reference to the EDTQ-7 score, resulted in an area under the curve (AUC) of 0.64. Our analysis considered essential criteria of ETD as comparative tools, which were typical clinical complaints, and at least two of three conditions: a pathologic EDTQ-7, a type B/C tympanometry, and a positive independent expert evaluation. The corresponding AUC was 0.98. Chronic obstructive ETD was identified at a cutoff of 7, with a sensitivity of 96% and a specificity of 96%, using the novel ETS-7. CONCLUSIONS: ETS is a valid and reliable instrument in adult patients with chronic obstructive ETD. ETS-7, with a cutoff point of ≤7, should facilitate the diagnosis of ETD and might be valuable as a diagnostic follow-up tool.

Treatment of the patulous Eustachian tube with soft-tissue bulking agent injections.

OBJECTIVE: A patulous Eustachian tube ([ET] tuba aperta) may cause symptoms as autophony, breath synchronous tinnitus, pressure sensation, and conductive hearing loss and thus lead to an enormous cutback in quality of life. In combination with "sniffing," it can trigger the development of cholesteatoma. Because of the ambiguous symptoms, the diagnosis can be challenging. A patulous ET can only be diagnosed through a well-structured examination, including patient history, physical examination with thorough observation of the movements of the tympanic membrane, and tympanometry with reflex-decay. STUDY DESIGN AND METHODS: Transnasal endoscopic injection of injectable soft-tissue bulking agent into the torus tubarius was performed in 20 patients as a new treatment option for patulous ET. All patients were followed up 6 weeks and 6 and 12 months after treatment. For each intervention, 0.8 to 2 mL of injectable soft-tissue bulking agent was used. RESULTS: In nine patients, more than one procedure was necessary. On follow-up, 10 out of 15 patients were satisfied with the result. Only three out of 15 patients reported no improvement of their symptoms. The procedure was minimally invasive, fast, and easy to perform. CONCLUSION: There is no gold standard for the therapy of patulous ET. The injection of soft-tissue bulking agent in the torus tubarius is a new minimally invasive therapeutic approach, but much more clinical experience is needed.

1,8-Cineol Reduces Mucus-Production in a Novel Human Ex Vivo Model of Late Rhinosinusitis.

Inflammatory diseases of the respiratory system such as rhinosinusitis, chronic obstructive pulmonary disease, or bronchial asthma are strongly associated with overproduction and hypersecretion of mucus lining the epithelial airway surface. 1,8-cineol, the active ingredient of the pharmaceutical drug Soledum, is commonly applied for treating such inflammatory airway diseases. However, its potential effects on mucus overproduction still remain unclear.In the present study, we successfully established ex vivo cultures of human nasal turbinate slices to investigate the effects of 1,8-cineol on mucus hypersecretion in experimentally induced rhinosinusitis. The presence of acetyl-α-tubulin-positive cilia confirmed the integrity of the ex vivo cultured epithelium. Mucin-filled goblet cells were also detectable in nasal slice cultures, as revealed by Alcian Blue and Periodic acid-Schiff stainings. Treatment of nasal slice cultures with lipopolysaccharides mimicking bacterial infection as observed during late rhinosinusitis led to a significantly increased number of mucin-filled goblet cells. Notably, the number of mucin-filled goblet cells was found to be significantly decreased after co-treatment with 1,8-cineol. On a molecular level, real time PCR-analysis further showed 1,8-cineol to significantly reduce the expression levels of the mucin genes MUC2 and MUC19 in close association with significantly attenuated NF-κB-activity. In conclusion, we demonstrate for the first time a 1,8-cineol-dependent reduction of mucin-filled goblet cells and MUC2-gene expression associated with an attenuated NF-κB-activity in human nasal slice cultures. Our findings suggest that these effects partially account for the clinical benefits of 1,8-cineol-based therapy during rhinosinusitis. Therefore, topical application of 1,8-cineol may offer a novel therapeutic approach to reduce bacteria-induced mucus hypersecretion.

Zoledronic acid inhibits osteoclastogenesis in vitro and in a mouse model of inflammatory osteolysis.

This study assessed effects of the bisphosphonate zoledronic acid (ZLNA) on osteoclastogenesis. To assess the effect of ZLNA on osteoclast formation in vitro, we cultured mouse bone marrow cells under conditions that promote osteoclastogenesis. Administered at concentrations from 10(-6) to 10(-9) mol/L, ZLNA led to a dose-dependent inhibition of osteoclastogenesis. Combined TUNEL staining and histochemical staining for tartrate-resistant acid phosphatase showed that ZLNA induced apoptosis in osteoclasts and monocytic precursor cells. To study the effects of ZLNA in vivo, we placed keratin particles onto the surface of the parietal bone of mice to induce localized inflammatory bone resorption. Three experimental groups received daily subcutaneous injections of ZLNA (1, 3, or 10 microg/kg body weight) from 4 days before surgery until 5 days after keratin implantation. The ZLNA significantly reduced osteoclast recruitment in a dose-dependent manner, but did not affect the degree of inflammation or the mineral apposition rate.

Computed tomography before balloon Eustachian tuboplasty--a true necessity?

OBJECTIVE: Since the introduction of balloon Eustachian tuboplasty the necessity of preoperative high-resolution CT scans of the temporal bone has been a topic of debate. This study investigated the informative value of preoperative CT scanning in predicting intraoperative or postoperative difficulties and complications. Special focus was laid on the existence of carotid canal dehiscences for fear of intraprocedural injury. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS AND INTERVENTIONS: Approximately 284 patients (510 Eustachian tubes) with intractable Eustachian tube dysfunction undergoing unilateral or bilateral balloon Eustachian tuboplasty with preoperative high-resolution CT scans of the temporal bone from January 1, 2009, to December 31, 2012. RESULTS: Carotid canal dehiscences were found in 18 patients (6.3%). In 3 patients (4 Eustachian tubes, 1.1% of patients) balloon dilatation could not be performed because of difficulties advancing the balloon catheter. Of these 3 patients, one had bilateral carotid canal dehiscences, whereas the other two had unremarkable CT scans. Postoperative complications occurred in 3 patients (1.1%): 2 soft tissue emphysemas and 1 unilateral hypoglossal paresis. All 3 patients had unremarkable CT scans, and all complications resolved completely without further sequelae. CONCLUSION: Preoperative high-resolution CT scan of the temporal bone does not seem to be suitable to predict intraoperative or postoperative difficulties of balloon Eustachian tuboplasty. Being extremely cautious during balloon catheter insertion into the Eustachian tube and using a device that is designed with a built-in stop mechanism preventing too deep insertion, the data presented suggest that fear of injury to the internal carotid artery during balloon dilatation might be disproportionate. Nevertheless, for inexperienced surgeons, HR-CT scans of the temporal bone may help to understand the relation between internal carotid artery and the Eustachian tube.

Identification of novel cholesteatoma-related gene expression signatures using full-genome microarrays.

BACKGROUND: Cholesteatoma is a gradually expanding destructive epithelial lesion within the middle ear. It can cause extensive local tissue destruction in the temporal bone and can initially lead to the development of conductive hearing loss via ossicular erosion. As the disease progresses, sensorineural hearing loss, vertigo or facial palsy may occur. Cholesteatoma may promote the spread of infection through the tegmen of the middle ear and cause meningitis or intracranial infections with abscess formation. It must, therefore, be considered as a potentially life-threatening middle ear disease. METHODS AND FINDINGS: In this study, we investigated differentially expressed genes in human cholesteatomas in comparison to regular auditory canal skin using Whole Human Genome Microarrays containing 19,596 human genes. In addition to already described up-regulated mRNAs in cholesteatoma, such as MMP9, DEFB2 and KRT19, we identified 3558 new cholesteatoma-related transcripts. 811 genes appear to be significantly differentially up-regulated in cholesteatoma. 334 genes were down-regulated more than 2-fold. Significantly regulated genes with protein metabolism activity include matrix metalloproteinases as well as PI3, SERPINB3 and SERPINB4. Genes like SPP1, KRT6B, PRPH, SPRR1B and LAMC2 are known as genes with cell growth and/or maintenance activity. Transport activity genes and signal transduction genes are LCN2, GJB2 and CEACAM6. Three cell communication genes were identified; one CDH19 and two from the S100 family. CONCLUSIONS: This study demonstrates that the expression profile of cholesteatoma is similar to a metastatic tumour and chronically inflamed tissue. Based on the investigated profiles we present novel protein-protein interaction and signal transduction networks, which include cholesteatoma-regulated transcripts and may be of great value for drug targeting and therapy development.

Isolation of novel multipotent neural crest-derived stem cells from adult human inferior turbinate.

Adult human neural crest-derived stem cells (NCSCs) are of extraordinary high plasticity and promising candidates for the use in regenerative medicine. Here we describe for the first time a novel neural crest-derived stem cell population within the respiratory epithelium of human adult inferior turbinate. In contrast to superior and middle turbinates, high amounts of source material could be isolated from human inferior turbinates. Using minimally-invasive surgery methods isolation is efficient even in older patients. Within their endogenous niche, inferior turbinate stem cells (ITSCs) expressed high levels of nestin, p75(NTR), and S100. Immunoelectron microscopy using anti-p75 antibodies displayed that ITSCs are of glial origin and closely related to nonmyelinating Schwann cells. Cultivated ITSCs were positive for nestin and S100 and the neural crest markers Slug and SOX10. Whole genome microarray analysis showed pronounced differences to human ES cells in respect to pluripotency markers OCT4, SOX2, LIN28, and NANOG, whereas expression of WDR5, KLF4, and c-MYC was nearly similar. ITSCs were able to differentiate into cells with neuro-ectodermal and mesodermal phenotype. Additionally ITSCs are able to survive and perform neural crest typical chain migration in vivo when transplanted into chicken embryos. However ITSCs do not form teratomas in severe combined immunodeficient mice. Finally, we developed a separation strategy based on magnetic cell sorting of p75(NTR) positive ITSCs that formed larger neurospheres and proliferated faster than p75(NTR) negative ITSCs. Taken together our study describes a novel, readily accessible source of multipotent human NCSCs for potential cell-replacement therapy.