Guidance of clinical management for patients with tonsillar focal disease.

Tonsillar focal diseases (TFDs) are defined as "diseases caused by organic and/or functional damage in organs distant from tonsil, and the disease outcome is improved by tonsillectomy." Although several reports and reviews have shown the efficacy of tonsillectomy for TFDs, no guidelines for the clinical management of the diagnosis and treatment of TFDs have been reported. Therefore, the Society of Stomato-pharyngology established a committee to guide the clinical management of patients with TFDs, and the original guide was published in May 2023. This article summarizes the English version of the manuscript. We hope that the concept of TFDs will spread worldwide, and that one as many patients with TFDs will benefit from tonsillectomy.

The Effects of Utilizing Cartilage Conduction Hearing Aids among Patients with Conductive Hearing Loss.

The cartilage-conduction hearing aid (CC-HA) is a new hearing device that is suitable for use in patients with conductive hearing loss. It has been 5 years since the introduction of the CC-HA. Although the number of users has increased, the CC-HA is not yet widely known. This study examines the effects of CC-HA on patients with conductive hearing loss and investigates factors that affect the willingness to use the device by comparing purchasers and non-purchasers of CC-HA in patients with unilateral conductive hearing loss. Eight patients had bilateral conductive hearing loss, and 35 had unilateral conductive hearing loss. Each patient underwent sound field tests and speech audiometry, and the effects of the CC-HA were compared with those of conventional bone conduction hearing aids (BC-HA). In patients with bilateral conductive hearing loss, the CC-HA was non-inferior to BC-HA. The CC-HA improved the hearing thresholds and speech recognition in patients with unilateral conductive hearing loss. Moreover, in patients with unilateral conductive hearing loss, experiencing the effect of wearing the CC-HA under conditions such as putting noise in the better ear could affect patients' willingness to use the CC-HA.

Inhibition of HDAC and Signal Transduction Pathways Induces Tight Junctions and Promotes Differentiation in p63-Positive Salivary Duct Adenocarcinoma.

BACKGROUND: The p53 family p63 is essential for the proliferation and differentiation of various epithelial basal cells. It is overexpressed in several cancers, including salivary gland neoplasia. Histone deacetylases (HDACs) are thought to play a crucial role in carcinogenesis, and HDAC inhibitors downregulate p63 expression in cancers. METHODS: In the present study, to investigate the roles and regulation of p63 in salivary duct adenocarcinoma (SDC), human SDC cell line A253 was transfected with siRNA-p63 or treated with the HDAC inhibitors trichostatin A (TSA) and quisinostat (JNJ-26481585). RESULTS: In a DNA array, the knockdown of p63 markedly induced mRNAs of the tight junction (TJ) proteins cingulin (CGN) and zonula occuludin-3 (ZO-3). The knockdown of p63 resulted in the recruitment of the TJ proteins, the angulin-1/lipolysis-stimulated lipoprotein receptor (LSR), occludin (OCLN), CGN, and ZO-3 at the membranes, preventing cell proliferation, and leading to increased cell metabolism. Treatment with HDAC inhibitors downregulated the expression of p63, induced TJ structures, recruited the TJ proteins, increased the epithelial barrier function, and prevented cell proliferation and migration. CONCLUSIONS: p63 is not only a diagnostic marker of salivary gland neoplasia, but it also promotes the malignancy. Inhibition of HDAC and signal transduction pathways is, therefore, useful in therapy for p63-positive SDC cells.

A hydroxypropyl methylcellulose plaque assay for human respiratory syncytial virus.

Quantifying proliferative virus particles is one of the most important experimental procedures in virology. Compared with classical overlay materials, newly developed cellulose derivatives enable a plaque-forming assay to produce countable clear plaques easily. HEp-2 cells are widely used in plaque assays for human respiratory syncytial virus (RSV). It is crucial to use an overlay material to keep HEp-2 cell proliferation and prevent RSV particles from spreading over the fluid. Among four cellulose derivatives, carboxymethyl cellulose sodium salt (CMC), hydroxypropyl methylcellulose (HPMC), microcrystalline cellulose (MCC), and hydroxyethyl cellulose (HEC), we found that HPMC was the optimal overlay material because HPMC maintained HEp-2 cell proliferation and RSV infectivity. Although MCC was unsuitable for RSV, it assisted the plaque-forming by human metapneumovirus in TMPRSS2-expressing cells. Therefore, depending on the cells and viruses, it is necessary to use different overlay materials at varying concentrations.

Narrow band imaging accentuates differences in contrast between cartilage and perichondrium in the elevation of the muco-perichondrium flap during septoplasty and open septorhinoplasty.

OBJECTIVE: In the elevation of the muco-perichondrium flap during septoplasty and septorhinoplasty, it is important to elevate the subperichondrial layer. When performing subperichondrial elevation of the flap, the surgeon uses differences in color tone to distinguish the perichondrium from cartilage; however, it is relatively difficult to understand these differences and to share them with assistants. Furthermore, the perichondrium at the caudal end adheres tightly to the cartilage, making it difficult to detach accurately the subperichondrial layer. Narrow band imaging (NBI) is an optical technology that facilitates detailed observation of microvessels in the mucosal surface layer. In this study, we investigated whether NBI is better than white light (WL) in accentuating differences in contrast between cartilage and perichondrium in the elevation of the muco-perichondrium flap during septoplasty and septorhinoplasty. METHODS: Twenty-six sides of 15 patients (the modified Killian approach was used in two patients, the hemitransfixion approach was used in seven patients, and open septorhinoplasty was used in six patients) with elevated muco-perichondrium flaps were studied under WL endoscopy and NBI. The brightness of the perichondrium and cartilage and the differences between the two tissues were compared between WL and NBI using ImageJ 1.53a. Next, the WL and NBI endoscopic images used for cartilage identification were divided into the three separate primary color channels of red, green, and blue, and the brightness of the perichondrium and cartilage were measured separately for each channel. RESULTS: Under WL, the perichondrium appeared reddish-white and the cartilage appeared white, whereas under NBI the perichondrium appeared greenish-gray, differentiating it from the white cartilage. The difference in brightness between the cartilage and perichondrium was significantly higher on NBI (grayscale difference 80.8 (SD 42.4)) than on WL imaging (grayscale difference 35.6 (SD 31.1)) (p<0.001). In the red channel, the difference in image intensity between cartilage and perichondrium was significantly higher on NBI than on WL imaging (Red WL grayscale difference -1.5 (SD 33.7), Red NBI grayscale difference 90.0 (SD 56.7); p<0.001). CONCLUSIONS: NBI is better than WL at accentuating the difference in contrast between cartilage and the perichondrium during the elevation of the muco-perichondrium flap during septoplasty and septorhinoplasty. The difference in the processing of red light between WL and NBI provides the largest contribution to the differentiation of cartilage from the perichondrium under WL and NBI. We believe that NBI can be usefully applied during septoplasty and septorhinoplasty to distinguish cartilage from the perichondrium with precision.

FOXO3/TGF-ß signal-dependent ciliogenesis and cell functions during differentiation of temperature-sensitive mouse cochlear precursor hair cells.

The transcription factor FOXO3 is necessary to preserve cochlear hair cells. Growth factors, including TGF-ß, closely contribute to cochlear hair cell regeneration. In the present study, to investigate the roles of FOXO3 in the ciliogenesis and cell functions of cochlear hair cells, UB/OC-2 temperature-sensitive mouse cochlear precursor hair cells were treated with TGF-ß receptor type 1 inhibitor EW-7197 or EGF receptor inhibitor AG-1478 after transfection with or without siRNA-FOXO3a. GeneChip analysis revealed that treatment with EW-7197 increased Foxo3 genes and decreased genes of Smads. During cell differentiation, treatment with EW-7197 or AG-1478 induced an increase in length of cilia-like structures that were positive for acetylated tubulin and inhibited cell migration. Treatment with EW-7197 also increased cell metabolism measured as mitochondrial basal respiration (oxygen consumption rate). The effects of EW-7197 were stronger than those of AG-1478. Knockdown of FOXO3 prevented the growth of cilia-like structures induced by EW-7197 or AG-1478 and induced cell migration under treatment with EW-7197. No change of the epithelial cell polarity molecule PAR3 was observed with any treatment. Treatment with the antimicrobial agent amikacin prevented the growth of cilia-like structures induced by EW-7197 and induced apoptosis. Pretreatment with the glucocorticoid dexamethasone inhibited the apoptosis induced by amikacin. This in vitro model of mouse cochlear hair cells suggests that FOXO3/TGF-ß signaling plays a crucial role in ciliogenesis and cell functions during differentiation of cochlear hair cells. This model is useful for analysis of the mechanisms of hearing loss and to find therapeutic agents to prevent it.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-ß Signaling in Human Nasal Epithelial Cells.

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-ß1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown. In the present study, to investigate how HMGB1 affects the barrier of normal human nasal epithelial cells, 2D and 2.5D Matrigel culture of primary cultured human nasal epithelial cells were pretreated with TGF-ß type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. Knockdown of angulin-1/LSR downregulated the epithelial barrier. Treatment with EW-7197 decreased angulin-1/LSR and concentrated the expression at tTJs from bTJs and increased the epithelial barrier. Treatment with a binder to angulin-1/LSR angubindin-1 decreased angulin-1/LSR and the epithelial barrier. Treatment with HMGB1 decreased angulin-1/LSR and the epithelial barrier. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen. Pretreatment with EW-7197 prevented the effects of HMGB1. HMGB1 disrupted the angulin-1/LSR-dependent epithelial permeability barriers of HNECs via TGF-ß signaling in HNECs.

HDAC inhibitors suppress the proliferation, migration and invasiveness of human head and neck squamous cell carcinoma cells via p63­mediated tight junction molecules and p21­mediated growth arrest.

In human head and neck squamous cell carcinoma (HNSCC), the invasion and metastatic properties of cancer cells are promoted by junctional adhesion molecule­A (JAM­A) and claudin­1; these are epithelial tight junction molecules regulated by histone deacetylases (HDACs) and transcription factor p63. HDAC expression is reportedly upregulated in HNSCC, and HDAC inhibitors suppress cancer cell proliferation by initiating proliferative arrest or apoptosis. However, little is known of the anti­cancer mechanisms of HDAC inhibitors in HNSCC. Thus, in the present study, the HNSCC Detroit 562 cell line and primary cultured HNSCC cells were treated with HDAC inhibitors to investigate their effects in HNSCC. Higher expression of p63, HDAC1, JAM­A and claudin­1 was observed in HNSCC tissues compared with the adjacent dysplastic regions. In Detroit 562 cells, treatment with trichostatin A (TSA), an inhibitor of HDAC1 and 6, downregulated the expression of p63, JAM­A and claudin­1, and upregulated that of acetylated tubulin; conversely, p63 knockdown resulted in the downregulation of JAM­A and claudin­1. Collectively, inhibiting HDAC suppressed the migration and invasiveness of cancer cells. In addition, treatment with TSA suppressed cancer cell proliferation via G2/M arrest, as well as upregulating p21 and downregulating cyclin D1 expression. TSA also downregulated the expression of epidermal growth factor receptor (EGFR) and phospho­ERK1/2. p63 knockdown and treatment with an EGFR inhibitor induced G1 arrest and downregulated EGFR and phospho­ERK1/2 levels, respectively. HDAC inhibition also suppressed the migration and invasiveness of primary cultured HNSCC cells. Collectively, the results of the present study indicate that HDAC inhibitors suppress the proliferation, migration and invasiveness of HNSCC by downregulating the p63­mediated tight junction molecules JAM­A and claudin­1, and inducing p63 or p21­mediated growth arrest.

Induction of airway progenitor cells via p63 and KLF11 by Rho-kinase inhibitor Y27632 in hTERT-human nasal epithelial cells.

Rho-kinase inhibitor Y27632, which is a factor in conditional reprogramming culture, induces airway progenitor clone formation. To investigate whether Y27632 enhances airway progenitor cells in nasal epithelium, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were treated with Y27632. In TERT-HNECs treated with Y27632 for 5 days, upregulation of p63, gap junction molecules Cx26, Cx30, Cx43, cytochrome P450 enzymes CYP2C9, CYP2C18, CYP39A1, CYP4B1, CYP2G1P, CYP4Z1, and KLF families KLF10 and KLF11 were observed compared to the control. Downregulation of tight junction molecules claudin-4, -7, and -23 was observed. Circumfential submembrane F-actin was also induced. The functions of gap junctional intercellular communication (GJIC) and the epithelial barrier were upregulated. Knockdown of p63 by siRNAs of TAp63 or ΔNp63 inhibited Cx26, Cx43 and CYP2C18, and induced claudin-1, and -4. Knockdown of KLF11 prevented p63 expression and enhancement of the epithelial barrier function by Y27632. In nasal mucosal tissues from patients with allergic rhinitis (AR), localized alteration of p63, KLF11, RhoA, Cx30 and claudin-4 was observed. Treatment with Y27632 in long-term culture induced airway progenitor cells via KLF11 in p63-positive human nasal epithelium. Airway progenitor cells of nasal epithelium induced by Y27632 is important in understanding upper airway disease-specific characteristics.

Rho-kinase and PKCα Inhibition Induces Primary Cilia Elongation and Alters the Behavior of Undifferentiated and Differentiated Temperature-sensitive Mouse Cochlear Cells.

Primary cilia, regulated via distinct signal transduction pathways, play crucial roles in various cellular behaviors. However, the full regulatory mechanism involved in primary cilia development during cellular differentiation is not fully understood, particularly for the sensory hair cells of the mammalian cochlea. In this study, we investigated the effects of the Rho-kinase inhibitor Y27632 and PKCα inhibitor GF109203X on primary cilia-related cell behavior in undifferentiated and differentiated temperature-sensitive mouse cochlear precursor hair cells (the conditionally immortalized US/VOT-E36 cell line). Our results indicate that treatment with Y27632 or GF109203X induced primary cilia elongation and tubulin acetylation in both differentiated and undifferentiated cells. Concomitant with cilia elongation, Y27632 treatment also increased Hook2 and cyclinD1 expression, while only Hook2 expression was increased after treatment with GF109203X. In the undifferentiated cells, we observed an increase in the number of S and G2/M stage cells and a decrease of G1 cells after treatment with Y27632, while the opposite was observed after treatment with GF109203X. Finally, while both treatments decreased oxidative stress, only treatment with Y27632, not GF109203X, induced cell cycle-dependent cell proliferation and cell migration.

Mechanism of fibrogenesis in submandibular glands in patients with IgG4-RD.

The aim of this study was to investigate the mechanisms driving fibrosis in the submandibular glands (SMG) of patients with IgG4-related disease (IgG4-RD). Immunohistochemistry showed that many fibroblast-like cells expressing IL-6, IL-18, TSLP, IL-33, and MMP1 were present in SMG from the affected patients. SMG fibroblasts were derived from patients with or without IgG4-RD and were cultured in vitro. Expression of IL-6, IL-18, TSLP, IL-33 and MMP1, the secretion of IL-6 and G2/M phase were upregulated in the fibroblasts from the affected patients. By treatment with inflammatory cytokines IL-1ß, TNFα or TGF-ß after treatment with or without the NF-κB inhibitor curcumin, curucumin blocked the production and secretion of IL-6 upregulated by IL-1ß, TNFα, or TNFα/TGF-ß in all fibroblasts. Wnt1-inducible signaling protein 1 (WISP1), which can enhance fibroblasts proliferation, was also more abundantly expressed in affected fibroblasts, while treatment with IL-6 induced WISP1, treatment with WISP1 increased the G2/M phase, and curucumin inhibited WISP1 induced by TNFα/TGF-ß in unaffected fibroblasts. IL-33 in affected fibroblasts was induced by IL-1ß, TNFα, or TNFα/TGF-ß, while the effect of IL-1ß or TNFα/TGF-ß was blocked by curcumin. These results suggest fibrosis in the SMG of affected patients is closely linked to the proliferation of fibroblasts following induction of IL-6 and WISP1 by inflammatory cytokines. The Th2 cytokines TSLP and IL-33 are also upregulated in affected SMG, and thus may cause chronic inflammation and IgG4 accumulation.

Guanylate binding protein-1-mediated epithelial barrier in human salivary gland duct epithelium.

Guanylate-binding protein-1 (GBP-1) is an interferon-inducible large GTPase involved in the epithelial barrier at tight junctions. To investigate the role of GBP-1 in the epithelial barrier, primary human salivary gland duct epithelial cells were treated with the the proinflammatory cytokines IFNγ, IL-1ß, TNFα and the growth factor TGF-ß. Treatment with IFNγ, IL-1ß, or TNFα markedly enhanced GBP-1 and the epithelial barrier function, and induced not only CLDN-7 but also the tricellular tight junction molecule lipolysis-stimulated lipoprotein receptor (LSR). Knockdown of GBP-1 by its siRNA induced endocytosis of tight junction molecules, and prevented the increases of CLDN-7 and LSR with the upregulation of the epithelial barrier function induced by treatment with IFNγ or TNFα. Treatment with a PKCα inhibitor induced expression of GBP-1, CLDN-7 and LSR and enhanced the epithelial barrier function. In almost intact salivary gland ducts from patients with IgG4-related disease (IgG4-RD) indicated significant infiltration of IgG-positive plasma cells, expression of GBP-1, CLDN-7 and LSR was increased. These findings indicated that GBP-1 might play a crucial role in barrier function of normal human salivary gland duct epithelium and perform a preventive role in the duct epithelium of IgG4-RD disease.

Regulation of claudin-4 via p63 in human epithelial cells.

P63 is a regulator of cell-cell junction complexes in the epidermis. Claudin-4 is regulated via various factors in normal epithelial cells and diseases. We found that claudin-4 was directly regulated via p63 (TAp63 and ΔNp63) in human keratinocytes and nasal epithelial cells. In the epidermis of atopic dermatitis (AD), which contains ΔNp63-deficient keratinocytes, high expression of claudin-4 was observed. In primary keratinocytes, downregulation of ΔNp63 by treatment with short interfering RNA (siRNA)-p63 induced claudin-4 expression. In nasal epithelial cells in the context of rhinitis or nasal polyps, upregulation of TAp63 and downregulation of claudin-4 were observed. In primary nasal epithelial cells transfected with the human telomerase reverse transcriptase gene, knockdown of p63 by siRNAs induced claudin-4 expression. Taken together, these findings indicate that p63 is a negative regulator of claudin-4 expression. Understanding the regulation of claudin-4 via p63 in human epithelial cells may be important for developing therapies for allergies and drug delivery systems.

The role of transcriptional factor p63 in regulation of epithelial barrier and ciliogenesis of human nasal epithelial cells.

Disruption of nasal epithelial tight junctions (TJs) and ciliary dysfunction are found in patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs), along with an increase of p63-positive basal cells and histone deacetylase (HDAC) activity. To investigate these mechanisms, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were transfected with siRNAs of TAp63 and ΔNp63, treated with the NF-kB inhibitor curucumin and inhibitors of HDACs, and infected with respiratory syncytial virus (RSV). In TERT-HNECs, knockdown of p63 by siRNAs of TAp63 and ΔNp63, induced claudin-1 and -4 with Sp1 activity and enhanced barrier and fence functions. The knockdown of p63 enhanced the number of microvilli with the presence of cilia-like structures. Treatment with curcumin and inhibitors of HDACs, or infection with RSV prevented expression of p63 with an increase of claudin-4 and the number of microvilli. The knockdown or downregulation of p63 inhibited phospho-p38MAPK, and the p38MAPK inhibitor downregulated p63 and upregulated the barrier function. Thus, epithelial barrier and ciliogenesis of nasal epithelium are regulated in a p63-negative manner in normal and upper airway diseases. Understanding of the regulation of p63/p38 MAPK/NF-κB may be important in the therapy for airway allergy and its drug delivery system.

Histone deacetylase inhibition prevents cell death induced by loss of tricellular tight junction proteins in temperature-sensitive mouse cochlear cells.

Tricellular tight junctions (tTJs) are specialized structures that occur where the corners of three cells meet to seal adjacent intercellular space. The molecular components of tTJs include tricellulin (TRIC) and lipolysis-stimulated lipoprotein receptor (LSR) which recruits TRIC, are required for normal hearing. Although loss of TRIC causes hearing loss with degeneration of cochlear cells, the detailed mechanisms remains unclear. In the present study, by using temperature-sensitive mouse cochlear cells, US/VOT-E36 cell line, we investigated the changes of TRIC and LSR during cochlear cell differentiation and the effects of histone deacetylase (HDAC) inhibitors against cell degeneration induced by loss of TRIC and LSR. During cell differentiation induced by the temperature change, expression of TRIC and LSR were clearly induced. Treatment with metformin enhanced expression TRIC and LSR via AMPK during cell differentiation. Loss of TRIC and LSR by the siRNAs induced cell death in differentiated cells. Treatment with HDAC inhibitors trichostatin A and HDAC6 inhibitor prevented the cell death induced by loss of TRIC and LSR. Collectively, these findings suggest that both tTJ proteins TRIC and LSR have crucial roles for the differentiated cochlear cell survival, and that HDAC inhibitors may be potential therapeutic agents to prevent hearing loss.

Loss of tricellular tight junction protein LSR promotes cell invasion and migration via upregulation of TEAD1/AREG in human endometrial cancer.

Lipolysis-stimulated lipoprotein receptor (LSR) is a unique molecule of tricellular contacts of normal and cancer cells. We investigated how the loss of LSR induced cell migration, invasion and proliferation in endometrial cancer cell line Sawano. mRNAs of amphiregulin (AREG) and TEA domain family member 1 (TEAD1) were markedly upregulated by siRNA-LSR. In endometrial cancer tissues, downregulation of LSR and upregulation of AREG were observed together with malignancy, and Yes-associated protein (YAP) was present in the nuclei. siRNA-AREG prevented the cell migration and invasion induced by siRNA-LSR, whereas treatment with AREG induced cell migration and invasion. LSR was colocalized with TRIC, angiomotin (AMOT), Merlin and phosphorylated YAP (pYAP). siRNA-LSR increased expression of pYAP and decreased that of AMOT and Merlin. siRNA-YAP prevented expression of the mRNAs of AREG and TEAD1, and the cell migration and invasion induced by siRNA-LSR. Treatment with dobutamine and 2-deoxy-D-glucose and glucose starvation induced the pYAP expression and prevented the cell migration and invasion induced by siRNA-LSR. siRNA-AMOT decreased the Merlin expression and prevented the cell migration and invasion induced by siRNA-LSR. The loss of LSR promoted cell invasion and migration via upregulation of TEAD1/AREG dependent on YAP/pYAP and AMOT/Merlin in human endometrial cancer cells.

The Behavior and Role of Lipolysis-stimulated Lipoprotein Receptor, a Component of Tricellular Tight Junctions, in Head and Neck Squamous Cell Carcinomas.

BACKGROUND/AIM: Lipolysis-stimulated lipoprotein receptor (LSR) knockdown has also been reported to increase the motility and invasiveness of certain cancer cells. Here, we describe, for the first time, the behavior and role of LSR in head and neck squamous cell carcinoma (HNSCC) in vivo and in vitro. MATERIALS AND METHODS: Samples of HNSCC, normal palatine tonsils, the pharynx carcinoma cell line Detroit562 and primary cultured HNSCC were characterized by immunostaining, western blot, real-time polymerase chain reaction (PCR), Matrigel invasion and proliferation assays. RESULTS: Protein and mRNA of LSR were strongly expressed, as well as claudin-1 in HNSCC tissues than in normal tissues, especially in invasive tissues. Knock-down of LSR and claudin-1 (CLDN-1), but not tricellulin (TRIC) by siRNAs, markedly induced invasiveness of Detroit562 cells and primary cultured HNSCC. LSR inhibited the development and progression of HNSCC. CONCLUSION: LSR is a potential target for new forms of head and neck cancer therapy.

Clarithromycin prevents human respiratory syncytial virus-induced airway epithelial responses by modulating activation of interferon regulatory factor-3.

Macrolide antibiotics exert immunomodulatory activity by reducing pro-inflammatory cytokine production by airway epithelial cells, fibroblasts, vascular endothelial cells, and immune cells. However, the underlying mechanism of action remains unclear. Here, we examined the effect of clarithromycin (CAM) on pro-inflammatory cytokine production, including interferons (IFNs), by primary human nasal epithelial cells and lung epithelial cell lines (A549 and BEAS-2B cells) after stimulation by Toll-like receptor (TLR) and RIG-I-like receptor (RLR) agonists and after infection by human respiratory syncytial virus (RSV). CAM treatment led to a significant reduction in poly I:C- and RSV-mediated IL-8, CCL5, IFN-ß and -λ production. Furthermore, IFN-ß promoter activity (activated by poly I:C and RSV infection) was significantly reduced after treatment with CAM. CAM also inhibited IRF-3 dimerization and subsequent translocation to the nucleus. We conclude that CAM acts a crucial modulator of the innate immune response, particularly IFN production, by modulating IRF-3 dimerization and subsequent translocation to the nucleus of airway epithelial cells. This newly identified immunomodulatory action of CAM will facilitate the discovery of new macrolides with an anti-inflammatory role.

Accessory parotid gland tumors: A series of 4 cases.

Accessory parotid gland tumors are clinically rare, and their management remains unclear. In this article, we describe our experience with 4 patients-2 males and 2 females, aged 13 to 66 years-who were diagnosed with an accessory parotid gland tumor. All patients presented with an asymptomatic midcheek swelling, and all underwent fine-needle aspiration biopsy, ultrasonography, computed tomography, and magnetic resonance imaging. A standard parotidectomy was performed on all patients. Postoperatively, 2 patients were found to have a malignant tumor, while the other 2 had a pleomorphic adenoma. No patient experienced any obvious facial nerve injuries postoperatively, and no recurrences were observed. We discuss the preoperative evaluation, treatment, and prognosis of these tumors, and we briefly describe the literature. The first choice of treatment for accessory parotid gland tumors is surgical resection. In our experience, a standard parotidectomy approach is safe and cosmetically appealing.

A Novel Drug Delivery System for the Human Nasal Epithelium.

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.