Published papers

Recently, petrous apex cholesterol granulomas (CGs) have been treated via the endoscopic endonasal transsphenoidal approach (EEA) using a silicone tube, to prevent drainage route occlusion. Occlusion of the drainage route has led to problems with recurrence. The aim of this report is to describe the use of a surgical technique to prevent drainage route occlusion. In surgical technique, the posterolateral wall of the sphenoid sinus was opened by EEA. After cyst debridement, a vascularized nasoseptal flap with a width of approximately 4 cm was inserted into the lumen with a silicone T-tube with a diameter of 7 mm. This technique was used in two patients: the first patient during the second operation after recurrence following occlusion of the drainage route, and the second patient during the first operation. Opening of the cyst wall was confirmed endoscopically in both patients 12–24 months after surgery, even after removal of the T-tube. In conclusion, the use of a pedicled nasoseptal flap with a silicone tube is useful to prevent CG recurrence, by paranasal cavitization of the cystic cavity.

The aim of this study was to determine whether autophagy and AMPK contribute to premature senescence in auditory cells. Incubating HEI-OC1 auditory cells with 5 mM H2O2 for 1 h induced senescence, as demonstrated by senescence-associated β-galactosidase (SA-β-gal) staining. H2O2 treatment significantly delayed populationdoubling time, leaving cell viability unchanged. Furthermore, the proportion of SA-β-gal-positive cells significantly increased. Autophagy-related protein expression increased, with Atg7 and LC3-II peaking 6 h and Lamp2 peaking 24 h after H2O2 treatment. The expression of these proteins decreased 48 h after treatment. Transmission electron microscopy revealed lipofuscin and aggregates within autolysosomes, which accumulated markedly in the cytoplasm of HEI-OC1 cells 48 h after treatment. Akt and P70S6 phosphorylation markedly decreased after H2O2 treatment, but 4EBP1 phosphorylation significantly increased 48 h after treatment. After RNAi-mediated knockdown (KD) of Atg7 and AMPK, H2O2-treated cells displayed dense SA-β-gal staining. Also, premature senescence was significantly induced. These suggest that a negative feedback loop may exist between autophagy and AMPK signaling pathways in HEI-OC1 cells. In our model, oxidative stress-induced premature senescence occurred due to impaired autophagy function through 4EBP1 phosphorylation. Our results also indicate that AMPK may regulate premature senescence in auditory cells in an autophagy-dependent and independent manner.

Conclusions: The functional connectivity (FC) between the right and left auditory cortex is weak in tinnitus patients. Transcranial direct current stimulation (tDCS) over the auditory cortex has potential as a tool to modulate auditory-based FC. Objective: This study investigated the effects of applying tDCS in tinnitus patients, and searched for modulation of brain networks in resting-state functional magnetic resonance imaging (rs-fMRI) through an analysis of FC with the stimulated brain region. Subjects and methods: Nine male patients with chronic tinnitus and 10 male volunteers with normal hearing were enrolled. The subjects were evaluated with rs-fMRI immediately before and after tDCS. The tinnitus patients filled out the self-evaluation questionnaires designed to measure tinnitus conditions before tDCS treatment and 1 week afterwards. Results: The FC between the right and left auditory cortex was significantly weaker in tinnitus patients than in controls. After tDCS treatment, in the tinnitus group, the primary auditory cortex showed a reduction in the amount of statistically significant connectivity with the somatosensory area and motor area, but maintained strong significant connectivity (p < 0.005) with the auditory area and insular cortex. In contrast, in the control group, there remained strong significant connectivity between the primary auditory cortex and the somatosensory area, motor area, insular cortex, and auditory area.

Systemic application of drugs is commonly used in clinical situations. Some of these drugs are ototoxic. Since there are few studies on in vivo monitoring of drug delivery dynamics, the time course or bioavailability of drugs in the inner ear of live animals following systemic drug application remains unknown. For instance, it is unknown whether the volume of a drug delivered systemically correlates with its inner ear pharmacokinetics. We previously established a new in vivo imaging system to monitor drug delivery in live mice. In the present study, we used this system to compare drug concentration in the inner ear over time after systemic drug injections. We used transgenic GFAP-Luc mice that harbor a firefly luciferase gene expression cassette regulated by 12 kb of murine GFAP promoter and human beta-globin intron 2. Luciferin delivered into the inner ear of these mice reacts with luciferase, and the resulting signals are detected in GFAP-expressing cells in the cochlear nerve. Thus, we assessed in the inner ear the intensity and duration of luciferin/luciferase signals after systemic injections of different volumes of luciferin. An IVIS® imaging system was used to observe signals, and these signals were compared to the drug dynamics of luciferin delivered through subcutaneous (sc) injections. The volume of sc-injected drug correlated significantly with photon counts measured in the inner ear. Photons were detected almost immediately after injection, peaking 20 min after injection. Drug concentration did not affect inner ear signals. Luciferin injected systemically appeared in the inner ear between highest and lowest concentration. Drug volume is an important parameter to know if the inner ear requires a higher level of the drug. We observed that it is the volume of a drug-not its concentration-that is the important factor. Indeed, the more volume of a drug injected systemically increased the concentration of that drug in the inner ear. This study provides a better understanding of in vivo drug delivery dynamics measured in the inner ear. Further studies will show whether a high dosage of drug is effective or not. This article is part of a Special Issue entitled .

Background: The side population (SP) of cancer cells is reportedly enriched with cancer stem cells (CSCs), however, the functional role and clinical relevance of CSC marker molecules upregulated in the SP of head and neck squamous carcinoma (HNSCC) cells are yet to be elucidated. Patients with clinical stage I/II (T1-2N0M0) tongue squamous cell carcinoma (TSCC) typically undergo partial glossectomy; however, development of delayed neck metastasis (DNM) tends to reduce their survival. In the present study, we aimed to determine the CSC markers in the SP of HNSCC cells along with their functions in cellular behaviors, and to clarify the association of these markers with DNM. Methods: Flow cytometry was applied to isolate SP from main population (MP) in HNSCC cells. The expression of the CSC markers was examined by semi-quantitative RT-PCR and immunocytochemistry. In vitro proliferation, migration, and invasion assays were performed to assess cellular behaviors. Clinicopathological factors and immunohistochemical expressions of Oct3/4 and Nanog were evaluated using surgical specimens from 50 patients with stage I/II TSCC. Results: SPs were isolated in all three cell lines examined. Expression levels of Oct3/4 and Nanog were higher in SP cells than MP cells. Additionally, cell migration and invasion abilities were higher in SP cells than MP cells, whereas there was no difference in proliferation. Univariate analysis showed that expression of Oct3/4 and Nanog, vascular and muscular invasion, and mode of invasion were significantly correlated with DNM. Multivariate logistic regression revealed that Oct3/4 expression (risk ratio = 14.78, p = 0.002) and vascular invasion (risk ratio = 12.93, p = 0.017) were independently predictive of DNM. Regarding the diagnostic performance, Oct3/4 showed the highest accuracy, sensitivity, and NPV of 82.0%, 61.5%, and 86.8%, respectively, while vascular invasion showed the highest specificity and PPV of 94.6% and 71.4%, respectively. Conclusion: These results suggest that Oct3/4 and Nanog represent probable CSC markers in HNSCC, which contribute to the development of DNM in part by enhancing cell motility and invasiveness. Moreover, along with vascular invasion, expression of Oct3/4 can be considered a potential predictor for selecting patients at high risk of developing DNM.

Objective: Closure of a tracheoesophageal puncture (TEP) formed during voice prosthesis implantation may sometimes be required. We report a new method of closure that we have termed the RESET method. Methods: We used the RESET method for four patients. An initial incision was made at the mucocutaneous junction of the tracheostoma, and the trachea and esophagus were separated. The TEP was sectioned, and the tracheal and esophageal sides were sutured into separate layers. A pedicled fascia flap lifted from the sternocleidomastoid muscle was sandwiched between the trachea and the esophagus, and subsequently secured. Results: The TEP was closed in all patients, and no complications were observed. Conclusion: The RESET method, using a pedicled fascia flap with stable perfusion, is a simple, reliable method of TEP closure.

In the field of regenerative medicine, cell transplantation or cell-based therapies for inner ear defects are considered to be promising candidates for a therapeutic strategy. In this paper, we report on a study that examined the use of magnetic resonance imaging (MRI) to monitor stem cells transplanted into the cochlea labeled with superparamagnetic iron oxide (SPIO), a contrast agent commonly used with MRI. First, we demonstrated in vitro that stem cells efficiently took up SPIO particles. This was confirmed by Prussian blue staining and TEM. In MRI studies, T2 relaxation times of SPIO-labeled cells decreased in a dose-dependent manner. Next, we transplanted SPIO-labeled cells directly into the cochlea in vivo and then performed MRI 1. h, 2 weeks, and 4 weeks after transplantation. The images were evaluated objectively by measuring signal intensity (SI). SI within the ears receiving transplants was significantly lower (P < 0.05) than that of control sides at the 1-h assessment. This novel method will be helpful for evaluating stem cell therapies, which represents a new strategy for inner ear regeneration. To the best of our knowledge, this study is the first to demonstrate that local transplantation of labeled stem cells into the inner ear can be visualized in vivo via MRI.

The sigma-1 receptor, which is expressed throughout the brain, provides physiological benefits that include higher brain function. The sigma-1 receptor functions as a chaperone in the endoplasmic reticulum and may control cell death and regeneration within the central nervous system. Cutamesine (1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl) piperazine dihydrochloride) is a ligand selective for this receptor and may mediate neuroprotective effects in the context of neurodegenerative disease. We therefore assessed whether cutamesine protects the inner ear from noise-induced or aging-associated hearing loss. Immunohistochemistry and Western blotting revealed that the sigma-1 receptor is present in adult cochlea. We treated mice with 0, 3, or 30 mg/kg cutamesine from 10 days before noise exposure until the end of the study. All subjects were exposed to a 120-dB, 4-kHz octave-band noise for 2 hr. We assessed auditory thresholds by measuring the auditory-evoked brainstem responses at 4, 8, and 16 kHz, prior to and 1 week, 1 month, or 3 months following noise exposure. For the aging study, measurements were made before treatment was initiated and after 3 or 9 months of cutamesine treatment. Damage to fibrocytes within the cochlear spiral limbus was assessed by quantitative histology. Cutamesine significantly reduced threshold shifts and cell death within the spiral limbus in response to intense noise. These effects were not dose or time dependent. Conversely, cutamesine did not prevent aging-associated hearing loss. These results suggest that cutamesine reduces noise-induced hearing loss and cochlear damage during the acute phase that follows exposure to an intense noise.

This study aimed to investigate the usefulness of intraluminal Pco 2 (Pico 2) monitoring by air tonometry for the assessment of the vascular condition of the transferred jejunum after surgery for hypopharyngeal cancer. Pico 2 in the transplanted jejunum of 24 patients was monitored using air tonometry after radical surgery for hypopharyngeal cancer from 2003 to 2010. All but 1 patient, who removed the catheter before monitoring began, were monitored safely. Pico 2 in the transferred jejunum correlated with arterial Pco 2 (Paco 2) that was measured concurrently, and dissociation of Pico 2 from Paco 2 was observed in cases with vascular complication. In those cases without postoperative vascular complication, the Pico 2 value gradually increased for 3 hours but then decreased by 12 hours after surgery. Three patients experienced major vascular complication. All 3 patients had continuous elevation of Pico 2 >100mm Hg, although vascular flow in 1 patient recovered by removal of a venous thrombosis and reanastomosis of the vein 7.5 hours after surgery. Four other patients who experienced elevation of Pico 2 had their skin suture released for decompression of their neck wound, resulting in a decrease in Pico 2 after treatment. The current results demonstrated that continuous monitoring of Pico 2 by air tonometry accurately reflects the vascular condition of the transferred jejunum, and this method is one of the best options for postoperative monitoring of jejunum blood perfusion.

INTRODUCTION: We commonly use data obtained prior to cervical lymph node biopsy for the diagnosis of malignant lymphoma. Based on such data, we can confirm whether a biopsy should be performed in some cases. Currently, the parameters used to indicate a presurgery examination prior to biopsy have been very few. So, we retrospectively analyzed cases of cervical lymph node biopsy. Moreover, we examined the usefulness of clinicobiological data obtained prior to cervical lymph node biopsy to evaluate various factors related to the diagnosis of malignant lymphoma.METHODS: This study included 77 patients for whom the initial diagnostic impression was malignant lymphoma before surgery. Of the 77 cases, 40 were diagnosed as having malignant lymphoma and 37 were diagnosed as having non-malignant lymphoma. We performed a case-controlled study to evaluate the differences in clinicobiological data between malignant and non-malignant lymphoma in terms of the following parameters: (1) age, (2) sex, (3) number of white blood cells, (4) white blood cell lymphocyte count, (5) percentage of white blood cell lymphocytes, (6) percentage of eosinophils (%), (7) percentage of monocytes (%), (8) atypical lymphocytes (%), (9) hemoglobin level, (10) lactate dehydrogenase level, (11) C-reactive protein level, (12) soluble interleukin-2 receptor (IL-2R) level, and (13) cytological findings. We used multivariate and univariate analyses to study the data statistically.RESULTS: The following 5 factors were found to be significant in a Wilcoxon t-test for malignant lymphoma: percentage of white blood cell lymphocytes, sIL-2R level, age, white blood cell lymphocyte count, and cytological findings; these factors were also significant when examined using a Pearson χ2 test. The other factors did not differ significantly between the malignant and non-malignant lymphomas. The percentage of white blood cell lymphocytes and the cytological findings were identified as significant independent factors for the diagnosis of malignant lymphoma in a multivariate analysis, whereas the other factors were not found to be significant.CONCLUSION: Based on the results of the univariate and multivariate analyses performed in the present study, the decline in the percentage of white blood cell lymphocytes and the cytological findings obtained prior to cervical lymph node biopsy are significant indicators of malignant lymphoma.

Introduction: We commonly use data obtained prior to cervical lymph node biopsy for the diagnosis of malignant lymphoma. Based on such data, we can confirm whether a biopsy should be performed in some cases. Currently, the parameters used to indicate a presurgery examination prior to biopsy have been very few. So, we retrospectively analyzed cases of cervical lymph node biopsy. Moreover, we examined the usefulness of clinicobiological data obtained prior to cervical lymph node biopsy to evaluate various factors related to the diagnosis of malignant lymphoma. Methods: This study included 77 patients for whom the initial diagnostic impression was malignant lymphoma before surgery. Of the 77 cases. 40 were diagnosed as having malignant lymphoma and 37 were diagnosed as having non-malignant lymphoma. We performed a case-controlled study to evaluate the differences in clinicobiological data between malignant and non-malignant lymphoma in terms of the following parameters: (l) age, (2) sex, (3) number of white blood cells, (4) white blood cell lymphocyte count, (5) percentage of white blood cell lymphocytes, (6) percentage of eosinophils (%), (7) percentage of monocytes (%), (8) atypical lymphocytes (%), (9) hemoglobin level. (10) lactate dehydrogenase level. (11) C-reactive protein level. (12) soluble interleukin-2 receptor (IL-2R) level, and (13) cytologi- cal findings. We used multivariate and univariate analyses to study the data statistically. Results: 'Hie following 5 factors were found to be significant in a Wilcoxon /-test for malignant lymphoma: Percent-age of white blood cell lymphocytes, sIL-2R level, age, white blood cell lymphocyte count, and cytological findings; these factors were also significant when examined using a Pearson X2 test. The other factors did not differ significantly between the malignant and non-malignant lymphomas. The percentage of white blood cell lymphocytes and the cytological findings were identified as significant independent factors for the diagnosis of malignant lymphoma in a multivariate analysis, whereas the other factors were not found to be significant. Conclusion: Based on the results of the univariate and multivariate analyses performed in the present study, the decline in the percentage of white blood cell lymphocytes and the cytological findings obtained prior to cervical lymph node biopsy are significant indicators of malignant lymphoma.

The main purposes of our study were to consider the effect of autophagy on auditory cells under oxidative stress, and the function of possible crosstalk among p62, Keap1 and Nrf2 in autophagy-deficient auditory cells. First, we described how cell death was induced in auditory cell line (HEI-OC1) exposed to H2O2. We found that the decision for the cell death of auditory cells under oxidative stress depends on the balance between autophagy and necrosis due to ATP depletion, and autophagy plays a cytoprotective function in oxidative stress-induced necrosis. Our data clearly suggested that autophagy was a cell survival mechanism in H2O2-induced cell death, based on the observation that suppression of autophagy by knockdown of Atg7 sensitized, whereas activation of autophagy by rapamycin protected against H2O2-induced cell death. Next, our results regarding the relationship among p62, Nrf2 and Keap1 by siRNA paradoxically showed that p62 creates a positive feedback loop in the Keap1/Nrf2 pathway. Autophagy impaired by Atg7 knockdown degrades Keap1 in a p62-dependent manner, whereas Nrf2 is activated. As a result, the cell death induced by H2O2 was promoted in auditory cells. Taken together, these results suggested that the autophagy pathway maintained signaling crosstalk with the Keap1-Nrf2 system through p62 in auditory cells under oxidative stress.

Supraclavicular Artery Island Flap (SCAIF) is a pedicled fasciocutaneous flap based on the supraclavicular artery and vein. Originally, SCAIF had been used for surgery on post-burn scars. However, it gradually came to be used for reconstruction after head and neck cancer resection. Although it has been shown as useful in foreign countries, there were no reports in Japan.We used SCAIFs for reconstruction after head and neck cancer resection in four cases. The time for harvesting the flap was about one hour and the donor site could be primarily closed. Only head and neck surgeons participated in the surgery, but it was not so difficult to harvest SCAIFs for surgeons experienced in harvesting various flaps.As a result, there were no flap failures in this series; however, one case experienced salivary leak, but this was managed via DP flap onlay. All of the patients could resume an oral diet without gastric tube supplementation.Therefore, we consider that SCAIF can be one of the options available for reconstruction after head and neck cancer resection.

Background: The purpose of this study was to analyze sphenoid sinus lateral pneumatization (SSLP), especially in Asian populations, and to identify cautionary items when using the endoscopic endonasal approach (EEA) for parasellar/lateral lesions. Methods: We analyzed SSLP and the width of SS (SSW) in 121 patients who had undergone EEA from 2008 to 2013 at the Division of Neurosurgery, Keio University Hospital. SSLP was defined as the distance between the SS lateral edge and the medial aspect of the pterygoid process on coronal reconstruction computed tomography. SSW was defined as the distance between the midline and lateral wall. We recorded SSLP and SSW for 242 sides. Further, we present two characteristic cases. Results: The average SSLP and SSW were 7.0 mm (-10.0-25.8 mm) and 21.8 mm (6.0-40.2 mm), respectively. No correlation between pneumatization and age was observed at age 15 or more. Sphenoid pneumatization was significantly wider in male than in female patients. There was no relationship between lateral and sagittal plane pneumatization. In a patient with recurrent chordoma who had an undeveloped SSLP, the tumor was removed via the medial space in the internal carotid artery. In another patient who had a giant pituitary adenoma and average SSLP, the tumor was located in the middle cranial fossa and was removed via the lateral internal carotid space through the left SSLP. Conclusions: Wide variations were observed in SSLP and SSW. For EEA, pneumatization is an instrument corridor. Preoperative assessment of SSLP is important, especially for parasellar lesions.

We report a case of auricular malformation treated by placement of an osseointegrated implant-supported epithesis using telenavigation and model simulation. A 66-year-old male suffering from auricular malformation and atresia auris of his right ear since birth visited our department in October 2006. The patient desired placement of an ear epithesis supported by osseointegrated implants. Computed tomographic (CT) scans were obtained for use in the navigation system as a prerequisite for the telenavigation and the operative plan was designed in consultation with an overseas oral and maxillofacial surgeon having rich experience in telenavigation surgery. We also constructed a preoperative simulation model and a mirror model of the unaffected left ear based on laser lithography to produce successful operation and symmetrical form of a symmetrical ear epithesis as contrast with identical to that on the left side. The osseointegrated implant surgery was carried out under telenavigation guidance. As a result, safe and accurate positioning of the implants was achieved and a symmetrical and elaborate epithesis could be fabricated.

Objectives: Using a large-scale nationwide survey database, we investigated the epidemiological characteristics for idiopathic SSNHL in Japan. Methods: The subjects for this analysis were patients registered in a Japanese multicentre database between April 2014 and March 2016. A total of 3419 idiopathic SSNHL patients were registered in the database, and the clinical characteristics of the idiopathic SSNHL patients were obtained. Several factors associated with the severity of hearing impairment and prognosis were then investigated. Statistical analysis was performed to clarify the factors associated with the severity of hearing impairment and prognosis. Results: There were significant correlations between the severity of hearing loss and diabetes mellitus, kidney disease, past history of brain infarction, heart disease, age (under 16 years/elderly), and symptoms of vertigo/dizziness. We also analyzed the prognostic factors for idiopathic SSNHL, and found that the severity of hearing loss (Grade 3 or 4), heart disease, aged 65 years or over, time from onset to treatment (over 7 days), and symptoms of vertigo/dizziness were all significantly related to poor prognosis. Conclusion: The present large-scale clinical survey revealed current epidemiological trends for idiopathic sudden sensorineural hearing loss (SSNHL) and various factors associated with the severity of hearing impairment and prognosis.

Objectives: The aim of this study was to investigate the differences between idiopathic sudden sensorineural hearing loss (SSNHL), and acute low-tone sensorineural hearing loss (ALHL) using the results of a nationwide survey database in Japan and to analyze the variables associated with their clinical features and the severity of hearing impairment, treatment, and prognosis. Methods: Participants were patients registered between April 2014 and March 2016 in a multicenter epidemiological survey database involving 30 university hospitals and medical centers across Japan. Statistical analysis was performed to clarify the factors associated with their clinical characteristics and the severity of hearing impairment, treatment, and prognosis. Results: Idiopathic SSNHL and ALHL differed significantly in terms of male-to-female ratio, age distribution, and time from onset to start of treatment. The treatment methods and hearing prognosis also differed markedly between the two diseases. A majority (92%) of idiopathic SSNHL patients were administered some type of corticosteroid, while half of the ALHL patients received corticosteroids and a diuretic agent. Conclusion: The results suggested that idiopathic SSNHL and ALHL belonged to different categories of inner ear disease.

Conclusions: The majority of hearing loss due to mumps presents as unilateral profound sensorineural hearing loss, which is refractory to treatment. In rare cases of bilateral total deafness, cochlear implants were beneficial for speech perception. Vaccination against mumps is recommended to prevent mumps-associated hearing loss. Objective: The objective of this study is to investigate the clinical characteristics of hearing loss due to mumps and to evaluate hearing outcomes. Subjects and methods: The clinical parameters were analyzed under a retrospective multi-institutional study design in patients diagnosed with hearing loss due to mumps at the Otolaryngology departments of 19 hospitals between 1987 and 2016. Results: Sixty-seven patients with hearing loss due to mumps were enrolled. The study population consisted of 35 males and 32 females, ranging in age from 1 to 54, with a median age of 9.5 years. Sixty-three patients presented with unilateral, and 4 with bilateral hearing loss. Profound hearing loss was observed in 65 ears. Only one ear with severe hearing loss showed complete recovery. Four patients with bilateral hearing loss received cochlear implant surgery. Most of the patients with hearing loss due to mumps had no history of vaccination.

Background: Hochuekkito (HKT), a traditional Japanese herbal medicine (Kampo), has been used to treat symptoms of several diseases. In a recent clinical study, HKT was shown to be protective against the influenza virus infection. However, the underlying mechanism of the prophylactic effect is not clear. Mitochondrial and glycolytic pathways play important roles in cellular energy metabolism to maintain biological functions. These metabolic pathways are affected by the influenza virus infection. In this study, we examined the relationship between the preventive effects of HKT against the influenza virus infection and cellular energy metabolism in mitochondria and glycolysis using Madin-Darby canine kidney cells and influenza A/PR/8/34 (H1N1) virus (IAV). Methods: Mitochondrial and glycolytic metabolic pathways were evaluated on the basis of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), respectively, using the XF24 Extracellular Analyzer. Results: The OCR/ECAR ratio in IAV-infected cells was lower than that in control cells. Cells that were treated with HKT before IAV infection showed a metabolic pattern similar to that in the control cells (increase in both OCR and ECAR). Conclusions: Our results suggest that HKT not only activates both mitochondrial and glycolytic energy metabolism in IAV-infected cells but also helps maintain metabolic homeostasis similar to that in noninfected cells.