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The epithelium of upper respiratory tissues such as the human nasal mucosa forms a continuous barrier via tight junctions (TJs). The development of a drug delivery system for use across the nasal mucosa is being reconsidered. In intranasal administration across the nasal mucosa, the paracellular pathway regulated by TJs is extremely important. It is known that the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) binds the TJ protein claudin and disrupts the tight junctional barrier without inducing a cytotoxic effect. We investigated the effects of C-CPE mutants on the function of TJs of human nasal epithelial cells (HNECs) and on the permeability of human recombinant insulin across HNECs treated with C-CPE 194 and C-CPE m19. We recently reported that C-CPE mutants 194 and m19 can regulate the permeability of insulin across HNECs via the MAPK pathway and may play a crucial role in therapy for various diseases via direct intranasal insulin administration. On the other hand, microRNAs (miRNAs) are known to regulate the expression of TJs as direct or indirect targets in genes to maintain barrier function. We investigated the effects of miRNAs on the epithelial barrier of HNECs and found that miRNA-146a plays crucial roles in the maintenance of the TJ barrier and innate immune response against invading pathogens. This chapter reviews a novel drug delivery system across the nasal mucosa from the point of view of the epithelial barrier function.

Anisakidosis is a nematode infection caused by the ingestion of larvae-infected raw or undercooked fish. Although gastric anisakiasis is a common disease in Japan due to the popularity of eating raw and undercooked fish, reports of anisakiasis in the tonsils are extremely rare. A 68-year-old man presenting with clinical features of peritonsillitis was admitted for examination. The right peritonsillar region exhibited slight edematous swelling and rash, and a white foreign body was observed. This foreign body was removed, and pathological examination revealed Anisakis.

Pneumolabyrinth is a rare condition with air bubbles existing in the vestibule and/or cochlea. We report a case of pneumolabyrinth without trauma that was suspected to be caused by labyrinthitis. A 65-year-old man presented with vertigo and hearing loss in the left ear after catching a cold. Computed tomography performed after there had been no improvement in the patient's symptoms showed the presence of air bubbles in the vestibule, semicircular canals and cochlea. The patient was transferred to our hospital with suspected perilymphatic fistula. Bacterial infection was suspected after the laboratory tests had indicated a severe inflammatory response, and the patient was treated with antibiotics. However, no bacteria were detected in a bacterial culture of the otorrhea. An exploratory tympanotomy was performed to improve the patient's staggering gait and to examine the middle ear, with no obvious fistula being observed. Subsequent fenestration of the round window revealed a white mass that appeared to contain bacteria which was collected from the cochlea and submitted for analysis and bacterial culture. However, no bacteria were detected and the mass contained white blood cells. We suspected pneumolabyrinth following labyrinth infection. However, the cause of air bubble formation remains unclear and needs to be validated with further research.

Seventy-three children who underwent plastic surgery for their external ear malformations between December 2010 and May 2013 at the Sapporo Medical University Hospital were evaluated. The predominance of right-sided malformation (62%) in males (71%) was similar to that reported previously, but the number of bilateral cases (9.3%) was lower than that in previous reports. We classified patients' ears using Marx's classification. The pure-tone average (average air conduction thresholds measured at 500, 1,000 and 2,000 Hz) was used as the representative value for the hearing level, which was compared with a patient's Marx classification. We evaluated the facial nerve position using high-resolution computed tomography scans. A thorough understanding of anatomical variations and complications, as well as performing appropriate treatments, is required for otolaryngologists to effectively manage congenital microtia.

Nose- or nasopharynx-associated lymphoid tissue (NALT) has a unique role that is distinct from that of other lymphoid tissues. During upper airway mucosal immune response, NALT induces a variety of responses, including cytokine and chemokine production and innate immune response, to establish acquired immunity. NALT consists of epithelial cells, epithelium-associated lymphoid tissues such as IgA-committed B cells, innate lymphocytes, T helper cells and dendritic cells. Intranasal immunization has recently been shown to effectively induce a proactive immune response in the local mucosa in addition to a systemic immune response. A variety of factors can cause otitis media, including Eustachian tube dysfunction, inflammation, allergy and viral and bacterial infections. However, the detailed pathogenesis of otitis media is not yet completely understood. In this report, we provide evidence suggesting that adenoid tissue as a component of NALT in children may play an important role in inducing innate immunity following viral infection.

The tonsils are located at the entrance of the pharynx as a cardinal constituent of Waldeyer's ring, taking part not only in local immune responses, but also in systemic immunity. Functional deficits of tonsils primarily underlie the pathogenesis of various characteristic disorders, including tonsillar focal infections such as palmoplantar pustulosis and IgA nephropathy, in addition to the highly prevalent sleep disorder called obstructive sleep apnea syndrome. Although the mechanisms underlying these disorders remain unknown, the tonsils have long been postulated as a unique and enigmatic immune organ. Lymphoid cells and tissues from surgically resected tonsils are often employed to analyze the human immune response from a retrospective view. This approach has provided much new fundamental evidence for understanding innate and acquired immune responses, thereby facilitating further studies in the fields of mucosal immunity and specific humoral immunity originating in the germinal center. Future studies of the tonsils in basic and clinical research are expected to reveal the mechanisms of tonsil-related disorders as well as the nature of human immunity. In this review, which is primarily based on our original research over the past 3 decades, we summarize our findings and discuss the future prospects of studies focusing on the tonsils.

It is necessary for the surgeon to be familiar with frontal recess anatomy during an endoscopic approach to the frontal sinuses. The aim of this study was to evaluate the prevalence of frontal recess cells in Japanese adults as well as the association between the frontal recess and the location of the anterior ethmoidal artery (AEA). The frontal recess cells and the AEAs were retrospectively evaluated in CT scans of the nasal and paranasal sinuses for 89 patients. The prevalence of agger nasi cells was 90.7%. The frequency of frontal cell types 1, 2, 3 and 4 was 28.8, 0.6, 2.6 and 0%, respectively. Suprabullar cells (SBCs) and frontal bullar cells (FBCs) were identified in 78/96 sides (81.3%) and 24/96 sides (24%), respectively. The prevalence of the medial group of frontal recess cells (interfrontal sinus septal cells) was 12.4%. In 42/61 sides (68.9%), the AEAs were located within the posterior margin of the SBCs or the FBCs. Therefore, SBCs, FBCs and the vertical portion of the middle turbinate are reliable landmarks for the identification of AEAs.

In the sensory hair cells of the mammalian cochlea, the primary cilia in the planar cell polarity as well as the tight junctions in the epithelial cell polarity and the barrier are important to maintain normal hearing. Temperature-sensitive mouse cochlear precursor hair cells were used to investigate the behavior of primary cilia and tricellular tight junction proteins during the differentiation of sensory hair cells. In undifferentiated cells (incubated at 33°C), many acetylated tubulin-positive primary cilia were observed, and each was accompanied with an x03B3;-tubulin-positive basal body. The primary cilia had a '9 + 0' architecture with nine outer microtubule doublets but lacking a central pair of microtubules. In differentiated cells (incubated at 39°C), acetylated tubulin-positive primary cilia as well as acetylated tubulin-positive cilia-like structures were partially observed on the cell surface. In differentiated cells, the number of primary cilia was markedly reduced compared with undifferentiated cells, and innumerable cilia-like structures with no ciliary pockets were partially observed on the cell surface. In undifferentiated cells, few tricellulin molecules and lipolysis-stimulated lipoprotein receptors (LSRs) were observed in the cytoplasm. In differentiated cells, many tricellulin molecules and LSRs were observed on the membranes and within the cytoplasm. Conditional immortalized mouse cochlear precursor hair cells may be useful to investigate the roles of primary cilia and tricellular tight junctions during cellular differentiation and degeneration such as apoptosis.

Inflammasomes, large protein complexes typically consisting of a Nod-like receptor (NLR), adapter protein apoptosis-associated speck-like protein containing CARD (ASC) and caspase-1, are postulated to be activated in response to danger signals arising from tumors. Inflammasomes are thought to have critical but contrasting roles through facilitating antitumor immunity and inducing oncogenic factors. However, the role and function of inflammasomes in oropharyngeal carcinoma remain unclear. We analyzed nine specimens of oropharyngeal squamous cell carcinoma (SCC) and determined the expression of NLRP3, ASC, interleukin (IL)-1β, IL-18 and caspase-1 in the specimens with and without human papilloma virus (HPV) infection using immunohistochemistry, and analyzed the correlations between the altered expression of these proteins and clinicopathological factors of oropharyngeal SCC. We found strong expression of NLRP3, ASC, IL-1β, IL-18 and caspase-1 in human oropharyngeal SCC and weak or no expression of these proteins in normal tonsils. Furthermore, the distribution of mindbomb E3 ubiquitin protein ligase 1 and inflammasome-associated proteins in oropharyngeal SCC was not significantly different; there was no correlation between the expression of inflammasome-associated proteins and HPV infection. These findings suggest that inflammasomes in oropharyngeal SCC play a key role through facilitating antitumor immunity and the possibility of new roles for inflammasomes in the oropharynx.

In an aging society, the number of patients suffering from vertigo and dizziness is increasing. Vertigo is mostly thought to occur owing to otorhinolaryngologic disease. In contrast, it is difficult to diagnose dizziness, because of its varied causes, and we believe that the number of elderly patients suffering from dizziness is increasing. Here, we evaluated the relationship between canal paralysis and symptoms at the first medical examination and age-related changes in caloric response, and obtained the following 3 main findings: (a) 41.3% of the patients with canal paralysis complained of dizziness at the first medical examination, with an increased tendency in patients aged >70 years; (b) the slow-phase eye velocity (SPEV) of patients aged >70 years was lower than that of patients aged ≤69 years, and the SPEV of patients complaining of vertigo was higher than that of patients who complained of dizziness during a caloric test, and (c) the percentage of patients complaining of dizziness and those not complaining of symptoms during a caloric test increased with age. In conclusion, patients with canal paralysis tend to complain of dizziness at the first medical examination, and the percentage of patients without vertigo during a caloric test increased with age.

Cochlear implantation (CI) has proven to be an effective treatment for severe bilateral sensorineural hearing loss (SNHL). Inner ear malformation is a rare anomaly and occurs in approximately 20% of cases with congenital SNHL. In cases with cochlear malformation, CI can be successfully performed in nearly all patients, the exceptions being those with complete labyrinthine and cochlear aplasia. It is important to evaluate the severity of inner ear deformity and other associated anomalies during the preimplantation radiological assessment in order to identify any complication that may potentially occur during the surgery and subsequent patient management.

Sleep is important for children pertaining to their physical and mental growth. Obstructive sleep apnea syndrome (OSAS) in children has been shown to have different effects as compared to OSAS in adults, including deficits in cognition and neuropsychological functions, hyperactivity, ADHD, behavior problems, aggressive behavior, learning problems and nocturnal enuresis. Hypertrophy of the adenoids and tonsils is a major cause of OSAS in children; therefore, adenotonsillectomy may decrease the effects of OSAS pertaining to physical and mental growth. It is important to accurately diagnose and appropriately treat OSAS in children to prevent OSAS in their adulthood.