Isobutyric acid enhances the anti-tumour effect of anti-PD-1 antibody.

The low response rate of immune checkpoint inhibitors (ICIs) is a challenge. The efficacy of ICIs is influenced by the tumour microenvironment, which is controlled by the gut microbiota. In particular, intestinal bacteria and their metabolites, such as short chain fatty acids (SCFAs), are important regulators of cancer immunity; however, our knowledge on the effects of individual SCFAs remains limited. Here, we show that isobutyric acid has the strongest effect among SCFAs on both immune activity and tumour growth. In vitro, cancer cell numbers were suppressed by approximately 75% in humans and mice compared with those in controls. Oral administration of isobutyric acid to carcinoma-bearing mice enhanced the effect of anti-PD-1 immunotherapy, reducing tumour volume by approximately 80% and 60% compared with those in the control group and anti-PD-1 antibody alone group, respectively. Taken together, these findings may support the development of novel cancer therapies that can improve the response rate to ICIs.

A manual of Eustachian tube function tests-illustration of representative test results obtained from healthy subjects and typical disorders with suggestion of the appropriate test method of choice.

In the 19th century, Politzer devised a method to measure passage of the Eustachian tube (ET) by pressurizing the nasopharyngeal cavity, which marked the beginning of the ET function test. Since then, various examination methods have been developed. While ET function testing is important, recent advancements in diagnostic imaging and treatments have renewed interest on its importance. In Japan, the main objective methods used for examining ET function include tubotympanoaero-dynamic graphy (TTAG), sonotubometry, and the inflation-deflation test. The Japan Otological Society (JOS) Eustachian Tube Committee has proposed a manual of ET function tests, which presents typical patterns of the normal ear and typical diseases and suggests the ET function test of choice for each disease. However, the diagnosis of each disease should be made based on a comprehensive history and various examination findings, with ET function tests playing a supplemental role in the diagnosis.

Residual nasal polyp tissue following dupilumab therapy is associated with periostin-associated fibrosis.

PURPOSE: Dupilumab, an anti-interleukin-4 receptor alpha monoclonal antibody, is a new treatment for severe uncontrolled chronic rhinosinusitis with nasal polyps. However, data on the effect of dupilumab on histological changes in nasal polyp tissue are lacking. We aimed to investigate the effect of dupilumab on real-life clinical conditions and nasal polyp tissues from patients with eosinophilic chronic rhinosinusitis (ECRS), which is a refractory subtype. METHODS: We conducted an open-label, prospective, observational, single-centre study on 63 patients with refractory ECRS on the basis of the criteria of the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis Study. These patients had a history of surgery and received dupilumab for 24 weeks. Patient-reported sinonasal symptoms, T&T olfactometry and nasal polyp scores were prospectively evaluated. In 23 patients with residual nasal polyps following dupilumab treatment, changes in systemic and local periostin expression, and total collagen deposition in nasal polyp tissues were investigated before and after dupilumab administration. RESULTS: Dupilumab rapidly improved sinonasal symptoms and reduced the nasal polyp score 24 weeks after initiation. 40 (63.5%) patients had resolution of nasal polyps, but the reduction was limited in the remaining 23 (36.5%) patients. Periostin expression in serum and nasal lavage fluid was decreased, whereas periostin and the total collagen deposition area in subepithelial tissues in residual nasal polyps were enhanced after dupilumab administration. CONCLUSION: Dupilumab improves sinonasal symptoms and reduces the nasal polyp score in refractory ECRS. Periostin-associated tissue fibrosis may be involved in the differential effect of dupilumab on nasal polyp reduction.

The Utility of Pneumatic Cavity Volume in the Treatment of Exudative Otitis Media in Children with Cleft Palate.

OBJECTIVE: Measure the volume of air-containing space in children with cleft palate and assess age-related changes, recurrence rate of otitis media with effusion (OME) after tube removal, and temporal bone development trend based on time of tube placement. DESIGN: Interventional prospective study. SETTING: Cleft Lip and Palate Center at a Tertiary-level institution. PATIENTS/PARTICIPANTS: One hundred sixty-eight ears of 86 patients who visited our center from January 2018 to December 2019. INTERVENTIONS: We performed tympanometry (impedance audiometry) after tube placement. MAIN OUTCOME MEASURES: Recurrence (at least one episode of OME after tympanic membrane closure), tympanic cavity volumes, and timing of tube placement. RESULTS: The mean air-containing cavity volume was 1.62 mL, 2.99 mL, and 3.29 mL in patients aged 1, 2, and 3 years, respectively. A rapid increase in volume was observed around 2 years of age. Twenty-two (42.3%) of the 52 ears with pneumatic cavity volumes <3 mL, and four (14.3%) of the 28 ears with pneumatic cavity volumes ≥3 mL had recurrence. Tubes were placed at ages <1 year and ≥1 year in 28 and 62 ears, respectively. The pneumatic cavity volume tended to be greater in the ears with tube placement at age <1 year. CONCLUSION: This study provided insights into using pneumatic cavity volume measurements to determine the appropriate timing for tube removal. Tubes should be placed as early as possible (before the age of 2 years) for prolonged OME associated with children with cleft palate.

Eosinophilic granulomatosis with polyangiitis developed after dupilumab administration in patients with eosinophilic chronic rhinosinusitis and asthma: a case report.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a form of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis characterized by eosinophil-rich granulomatous inflammation and small-to-medium vessel vasculitis associated with asthma, rhinosinusitis, and eosinophilia. EGPA is often difficult to distinguish from severe asthma and eosinophilic chronic rhinosinusitis (ECRS) in cases when there are no findings that suggest vasculitis. Dupilumab, an anti-IL-4Rα monoclonal antibody, is expected to be effective in eosinophilic airway inflammatory diseases, such as refractory asthma and chronic rhinosinusitis (CRS). Although transient eosinophilia and eosinophilic pneumoniae have been reported in patients with refractory asthma and CRS associated with dupilumab, few studies have examined the development of EGPA. CASE PRESENTATION: We report a case of a 61-year-old woman treated with dupilumab for refractory ECRS and eosinophilic otitis media (EOM) complicated by severe asthma. Although she had a previous history of eosinophilic pneumoniae and myeloperoxidase (MPO) ANCA positivity, there were no apparent findings of vasculitis before the initiation of dupilumab. After the second administration of dupilumab, several adverse events developed, including worsening of ECRS, EOM and asthma, and neuropathy. A blood test showed an eosoinophilia and re-elevation of MPO-ANCA levels after the administration of dupilumab. Therefore, dupilumab was discontinued owing to the development of EGPA, and prednisolone and azathioprine administration was initiated for a remission induction therapy. CONCLUSION: To the best of our knowledge, this is the first case report that suggests that dupilumab may directly trigger the manifestation of vasculitis in patients who were previously MPO-ANCA-positive. Although the precise mechanism of how dupilumab could trigger the development of EGPA requires further elucidation, measuring MPO-ANCA in patients with multiple eosinophilic disorders before the initiation of dupilumab might be helpful when considering the possibility of a latent EGPA. When administering dupilumab to patients with a previous history of MPO-ANCA positivity, clinicians must carefully monitor and collaborate with other specialists in the pertinent fields of study for appropriate usage.

Role of the amygdala-medial orbitofrontal relationship in odor recognition in the elderly.

INTRODUCTION: In patients with mild cognitive impairment, pathological changes begin in the amygdala (AMG) and hippocampus (HI), especially in the parahippocampal gyrus and entorhinal cortex (ENT). These areas play an important role in olfactory detection and recognition. It is important to understand how subtle signs of olfactory disability relate to the functions of the above-mentioned regions, as well as the orbitofrontal cortex (OFC). In this study, we evaluated brain activation using functional magnetic resonance imaging (fMRI), performed during the presentation of olfactory stimuli (classified as "normal odors" not inducing memory retrieval), and investigated the relationships of the blood oxygen level-dependent (BOLD) signal with olfactory detection and recognition abilities in healthy elderly subjects. METHODS: Twenty-four healthy elderly subjects underwent fMRI during olfaction, and raw mean BOLD signals were extracted from regions of interest, including bilateral regions (AMG, HI, parahippocampus, and ENT) and orbitofrontal subregions (frontal inferior OFC, frontal medial OFC, frontal middle OFC, and frontal superior OFC). Multiple regression and path analyses were conducted to understand the roles of these areas in olfactory detection and recognition. RESULTS: Activation of the left AMG had the greatest impact on olfactory detection and recognition, while the ENT, parahippocampus, and HI acted as a support system for AMG activation. Less activation of the right frontal medial OFC was associated with good olfactory recognition. These findings improve our understanding of the roles of limbic and prefrontal regions in olfactory awareness and identification in elderly individuals. CONCLUSION: Functional decline of the ENT and parahippocampus crucially impacts olfactory recognition. However, AMG function may compensate for deficits through connections with frontal regions.

Clinical practice guidelines for the diagnosis and management of otitis media with effusion (OME) in children in Japan - 2022 update.

This is an update of the 2015 Guidelines developed by the Japan Otological Society and Oto-Rhino-Laryngeal Society of Japan defining otitis media with effusion (OME) in children (younger than 12 years old) and describing the disease rate, diagnosis, and method of examination. Recommended therapies that received consensus from the guideline committee were updated in consideration of current therapies used in Japan and based on available evidence. METHOD: Regarding the treatment of OME in children, we developed Clinical Questions (CQs) and retrieved documents on each theme, including the definition, disease state, method of diagnosis, and medical treatment. In the previous guidelines, no retrieval expression was used to designate a period of time for literature retrieval. Conversely, a literature search of publications from March 2014 to May 2019 has been added to the JOS 2015 Guidelines. For publication of the CQs, we developed and assigned strengths to recommendations based on the collected evidence. RESULTS: OME in children was classified into one group lacking the risk of developing chronic or intractable disease and another group at higher risk (e.g., children with Down syndrome, cleft palate), and recommendations for clinical management, including follow-up, is provided. Information regarding management of children with unilateral OME and intractable cases complicated by adhesive otitis media is also provided. CONCLUSION: In clinical management of OME in children, the Japanese Clinical Practice Guidelines recommends management not only of complications of OME itself, such as effusion in the middle ear and pathologic changes in the tympanic membrane, but also pathologic changes in surrounding organs associated with infectious or inflammatory diseases.

Case Report: A 29-Year-Old Pregnant Woman at 24 Weeks of Gestation Presenting with Laryngotracheitis and COVID-19 Due to the R.1 Variant of SARS-CoV-2.

BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was discovered in December 2019 in Wuhan, China. Coronavirus disease (COVID-19) mainly presents with lower respiratory tract symptoms. On the other hand, laryngotracheitis or croup shows barky cough and it is rare in adults. There were no reports of laryngotracheitis with COVID-19 in pregnant women. We report the case of a pregnant woman at 24 weeks of gestation presenting with acute laryngotracheitis and COVID-19 due to the R.1 variant of SARS-CoV-2. CASE REPORT A 29-year-old previously healthy woman at 24 weeks of gestation presented with hoarseness and sore throat without fever, of 1-day duration. Although she was treated by her primary care physician with nebulized epinephrine, her symptoms did not resolve. She came to our hospital the same day. On arrival at our department, she was tachypneic and had a 95% oxygen saturation. She had stridor and barking cough. Laryngeal endoscopy revealed edema under the vocal cords. She was hospitalized urgently. SARS-CoV-2 polymerase chain reaction (PCR) testing was positive and the E484K mutation was confirmed. She was treated with oral and inhaled corticosteroids. Two days after admission, her symptoms were improved. She was discharged 10 days after admission. Edema under the vocal cords was completely improved 24 days after discharge. There were no adverse effects on the pregnancy. CONCLUSIONS COVID-19 laryngotracheitis has a more severe disease course than other causes, especially in pregnancy. COVID-19 laryngotracheitis should be use corticosteroids to treatment. Prednisolone is recommended for laryngotracheitis with COVID-19 during pregnancy.

A 32-Year-Old Man with Persistent Olfactory Dysfunction Following COVID-19 Whose Recovery Was Evaluated by Retronasal Olfactory Testing.

BACKGROUND Anosmia, which is loss of smell, is a recognized complication of coronavirus disease 2019 (COVID-19) due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may persist after recovery from infection. Retronasal olfactory testing includes both subjective questionnaires and physiological tests that can be used to evaluate recovery of smell. This report presents the case of a 32-year-old man with persistent loss of smell following COVID-19 whose recovery was evaluated by retronasal olfactory testing. CASE REPORT The patient was a 32-year-old man with confirmed SARS-CoV-2 infection. He was aware of his olfactory dysfunction. Using the orthonasal test, a T&T Olfactometer 2 months after disease onset showed an olfactory threshold score of 2.2 points (mild decrease) and olfactory identification result of 3.4 points (moderate decrease). However, the retronasal intravenous olfactory test showed no response, indicating severe olfactory dysfunction. After 3 months of olfactory training and therapy with steroidal nasal drops (Fluticasone Furoate, 27.5 µg/day) and oral vitamins (Mecobalamin, 1500 µg/day), the patient's orthonasal test olfactory threshold score improved to 0.6 points (normal), and his olfactory identification result improved to 1.2 points (mild decrease). Although the retronasal intravenous olfactory test showed a weak response, a reaction did occur. At this time, the patient did not report any improvement in his symptoms. CONCLUSIONS This report has shown that in cases of persistent anosmia following COVID-19, retronasal olfactory testing can be used to evaluate recovery of the sense of smell.

New granule cells in the olfactory bulb are associated with high respiratory input in an enriched odor environment.

New neurons are constantly generated in the olfactory bulb and the dentate gyrus of the hippocampus. The number of new cells depends on sensory experiences; an enriched odor environment increases neurogenesis and neural survival. The aim of this study was to investigate whether enriched olfactory stimuli affect neurogenesis of mitral and granule cells of the olfactory bulb and dentate gyrus, and whether respiratory activity accompanied by olfactory stimuli is associated with new cells in these regions. To this end, respiratory activity during enriched odor stimuli was continuously measured in mice and new cells were stained with 5-bromo-2'-deoxyuridine, which selectively labels proliferating cells. An enriched olfactory environment significantly increased neurogenesis of mitral and granule cells in the olfactory bulb, but not in the dentate gyrus. Additionally, an increase of new granule cells under the enriched odor condition was correlated to sniffing frequency power, which had a significantly different pattern from the no-odor condition. A high respiratory frequency with frequent odor stimuli may be associated with activation of granule cells to form inhibitory neurons and this active state might increase granule cell neurogenesis.

Pharmacotherapy focusing on for the management of otitis media with effusion in children: Systematic review and meta-analysis.

OBJECTIVE: To examine the evidence for treating children with otitis media with effusion with pharmacotherapy. DATA SOURCES: For the systematic review, data were retrieved from PubMed, Cochrane database, and the Japan Medical Abstracts Society Database (1st January 1995 through 31th May 2019). STUDY SELECTION: Articles addressing pharmacotherapy for the management of otitis media with effusion in children were selected in English. DATA EXTRACTION: The database was searched using the keywords "Otitis Media with effusion or secretory otitis media" and the following medical agents: carbocysteine, antihistamines, leukotriene receptor antagonist, and steroid nasal spray. DATA SYNTHESIS: After a critical review of 18 studies, studies addressing steroid nasal spray were eligible for quantitative synthesis. Intranasal steroids for OME showed no benefit with OR 1.155 (95% CI 0.834-1.598) within one month. Conversely, intranasal steroids have effects for OME with OR 1.858 (95% CI 1.240-2.786) for more than one month. CONCLUSIONS: We found evidence of benefit from treatment of OME in children with intranasal steroids and S-carboxymethylcysteine at longer-term follow-up.

Temporal Bone Pathology Secondary to Head Trauma-A Human Temporal Bone Study.

HYPOTHESIS/BACKGROUND: We hypothesize that following head trauma there is a difference in temporal bone (TB) pathology in cases with and without skull fracture. Although conductive, sensorineural, mixed hearing loss, and TB pathology following head trauma have been reported, to our knowledge, there are no studies that have compared the pathology of the TB in cases with and without skull fracture. METHODS: We analyzed 34 TBs from donors who had a history of head trauma (20 with skull fracture and 14 without fracture), and 25 age-matched controls without clinical or histological evidence of otologic disorders. We documented the presence and location of TB fracture, ossicular injury, and cochlear hemorrhage and evaluated the loss of spiral ganglion cells and sensory hair cells, damage to the stria vascularis, and the presence of endolymphatic hydrops. RESULTS: We found a significant loss of outer hair cells in the upper basal, lower, and upper middle turns of the cochlea (p = 0.009, =0.019, =0.040, respectively), a significant loss of spiral ganglion cells (p = 0.023), and cochlear hemorrhage predominantly in the basal turns secondary to head trauma. Interestingly, these findings were significantly observed in TBs from donors with a history of head trauma without skull fracture. CONCLUSION: The greatest damage was to the cochlear basal turn. Our findings suggest that head trauma may result in tonotopic high frequency sensorineural hearing loss. TBs from donors with skull fracture have less pathologic changes than those without.

Coronavirus Disease 2019 and Nasal Conditions: A Review of Current Evidence.

The nasal epithelium expressing enriched angiotensin-converting enzyme II (ACE2), the key cell entry receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), could serve as the first barrier to protect the airway from viral infection. Recent studies have demonstrated that higher viral loads were detected in the nasal cavity than the pharynx in coronavirus disease 2019 (COVID-19) patients, and otolaryngologists should carefully consider infection prevention in clinical practice for the treatment of nasal conditions. Moreover, several studies have indicated that anosmia is one of the clinical characteristics of COVID-19, but the precise prevalence and mechanism remain unclear. Thus far, comorbidity of allergic rhinitis and chronic rhinosinusitis do not seem to be a major risk factor for severe COVID-19. However, we should develop strategies in clinical practice for treatment of nasal diseases during the pandemic. In this article, we reviewed current evidence of the relationship between COVID-19 and nasal conditions, such as COVID-19-related olfactory dysfunction, allergic rhinitis, and chronic rhinosinusitis.

Survey of the Time-Onset Profiles of Nedaplatin-Induced Adverse Events in Head and Neck Cancer Therapy.

OBJECTIVE: Cisplatin(CDDP)is a key drug for head and neck cancer therapy, but frequently induces severe adverse events including renal dysfunction. Nedaplatin(CDGP)was developed and is used in Japan; it has certain benefits over CDDP. Unlike CDDP, CDGP treatment does not require hydration. However, CDGP is not used globally and thus safety information is lacking. Therefore, we surveyed safety profiles for CDGP-based chemotherapy. METHODS: A survey was conducted at Showa University Hospital. Thirty-eight patients treated for head and neck cancer combined with radiotherapy(RTx)and tegafur- gimeracil-oteracil(S-1)between April 2012 and March 2015 were included. Laboratory-based adverse events(WBC, Hb, platelet[Plt], SCr, Alb)and oral mucositis were assessed according to CTCAE v5.0. Time-onset profiles for adverse events were evaluated after starting chemoradiotherapy. RESULTS: In 38 patients, Plt nadir was observed following 40(30-70)Gy and sustained for 14(7-35)days. WBC patterns followed similar profiles, but for Hb, nadir was observed following 60(40- 70)Gy and was less frequently sustained throughout the RTx. Alb and SCr levels were not correlated with therapy. Oral mucositis was observed following 50(10-70)Gy. CONCLUSION: In conclusion, at approximately 40 Gy, we observed decreases in WBC and Plt, with an increase in oral mucositis. Based on these results, medical staffs must closely monitor patients, especially at doses within range of 40 Gy.

Temperature Measurements of the Semicircular Canal During Green Laser Irradiation of the Canal: A Preliminary Study.

BACKGROUND: Laser irradiation of the semicircular canal (SCC) is a good treatment for intractable benign paroxysmal positional vertigo. However, there were few reports on the temperature changes during laser irradiation. OBJECTIVE: To measure the internal temperature of the SCC and vestibule during green laser irradiation of the SCC and investigate morphologic changes using human temporal bones. METHODS: After the lateral SCC was blue-lined, a thermocouple was inserted into the SCC through a hole made in the canal wall. Another thermocouple was inserted into the vestibule through the oval window. Green laser was irradiated to the lateral canal wall. After the irradiation, the tissues were inspected as paraffin using HE staining. RESULT: The internal temperature of the SCC rose from 33 ° to 52 °C by a single laser irradiation of 1.5 W × 2 seconds and 82 °C by a single laser irradiation of 1.7 W × 3 seconds to the canal wall with a black spot. Continuous laser irradiation of 1.5 W × 3 seconds, 10 times resulted in a temperature rise of 92 °C from 33 °C. Throughout the whole experiments, temperatures within the vestibule were unchanged. Histopathology showed that the irradiated areas of the lateral canal wall were partially deficient with or without carbonization after single irradiation. By continuous laser irradiations, the SCC bony wall showed a peroration of 40 µm in diameter with carbonized edges. CONCLUSIONS: Green laser irradiation of the SCC produced char formation with perforation in the canal wall. High temperatures within the SCC were recorded for a short period of less than 30 seconds. However, the vestibule didn't show temperature changes.

Modulation of Th1/Th2 Cytokine Balance by Quercetin In Vitro.

Background: Allergic rhinitis (AR) is well known to be an IgE-mediated chronic inflammatory disease in the nasal wall, which is primarily mediated by Th2-type cytokines such as IL-4, IL-5, and IL-13. Although quercetin is also accepted to attenuate the development of allergic diseases such as AR, the influence of quercetin on Th2-type cytokine production is not well understood. The present study was designed to examine whether quercetin could attenuate the development of AR via the modulation of Th2-type cytokine production using an in vitro cell culture technique. Methods: Human peripheral-blood CD4+ T cells (1 × 106 cells/mL) were cultured with 10.0 ng/mL IL-4 in the presence or absence of quercetin. The levels of IL-5, IL-13, and INF-γ in 24 h culture supernatants were examined by ELISA. The influence of quercetin on the phosphorylation of transcription factors NF-κB and STAT6, and mRNA expression for cytokines were also examined by ELISA and RT-PCR, respectively. Results: Treatment of cells with quercetin at more than 5.0 µM inhibited the production of IL-5 and IL-13 from CD4+ T cells induced by IL-4 stimulation through the suppression of transcription factor activation and cytokine mRNA expression. On the other hand, quercetin at more than 5.0 µM abrogated the inhibitory action of IL-4 on INF-γ production from CD4+ T cells in vitro. Conclusions: The immunomodulatory effects of quercetin, especially on cytokine production, may be responsible, in part, for the mode of therapeutic action of quercetin on allergic diseases, including AR.

A Rare Case of Elongated Styloid Process Fracture.

BACKGROUND An elongated styloid process occurs with Eagle syndrome and causes a variety of symptoms. Fracture of the elongated styloid process is a rare condition. With spontaneous fractures, appropriate treatment cannot be performed in many cases due to unexplained symptoms and indefinite complaints that are not thoroughly examined. CASE REPORT We encountered a case of fractured elongate styloid process reaching the hyoid bone. Based on the findings from cervical 3-dimensional computed tomography (3D-CT), we chose surgery using the transcervical approach instead of the intraoral approach. Symptoms resolved following surgery. CONCLUSIONS A fractured styloid process is a rare event, but it needs to be recognized. If drug therapy does not work, surgical treatment is needed and has been shown to be effective. Surgical therapies include an intraoral approach and a transcervical approach. In the case presented here, 3D-CT was very useful for diagnosis and surgery selection.

Primary Ciliary Dyskinesia with Refractory Chronic Rhinosinusitis.

BACKGROUND Primary ciliary dyskinesia (PCD) is a rare genetic disease associated with abnormalities in the structure and function of cilia. The common clinical presentation of PCD is characterized by otitis media, chronic rhinosinusitis (CRS), chronic bronchitis, and infertility due to impaired ciliary motility. PCD is a complex disease and its diagnosis is complicated. However, there are some clinical features that are strong indicators of PCD, namely situs inversus, chronic otitis media, CRS, and chronic bronchitis with wet cough. CASE REPORT A 49-year-old male who had already received 3 operations for refractory CRS presented with nasal discharge, post nasal discharge, and chronic wet cough. Since childhood, he had suffered from otitis media, rhinosinusitis, and bronchitis. He also had a family history of CRS. He was diagnosed as having male infertility at another hospital, but the details were unknown. We performed a fourth surgery and obtained the nasal mucosa for electron microscope analysis during the operation. The transmission electron microscopic findings of the nasal cilia revealed several abnormalities in structure including a central complex defect, microtubular disorganization, and an inner dynein arm defect. Based on these findings and clinical courses, we made the definitive diagnosis of PCD. CONCLUSIONS When faced with refractory CRS cases with characteristic clinical symptoms that are associated with otitis media, chronic bronchitis, and infertility, clinicians should consider the possibility of PCD.