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Developmental changes in responsiveness of rat spiral ganglion neurons (SGNs) to neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) were examined using an explant culture system. Spiral ganglion (SG) explants at embryonic Day 18 (E18), postnatal Day 0 (P0), P5, P10 and P20 were cultured with the addition of either NT-3 or BDNF at various concentrations (0.1-100 ng/ml) and analyzed the dose-response characteristics of three parameters: SGN survival, the number of neurites emanating from the explants and the length of neurite extension. In E18 cultures, SGN survival and neurite number were enhanced more strongly by NT-3 than by the BDNF. As the explants became more mature, the effects of NT-3 decreased, whereas those of BDNF increased, peaking at P0. Although the intrinsic capacity of SGNs to produce and extend neurites declined considerably by P20, they still retained the capacity to respond to both NT-3 and BDNF. These temporal patterns in responsiveness of SGNs to neurotrophins correspond well to the expression pattern of the two neurotrophins in cochlear sensory epithelium in vivo and also correlate with the time course of developmental events in SGNs such as cell death and the establishment of mature hair cell innervation patterns. [ABSTRACT FROM AUTHOR]

Conclusions. Data about the recovery course of facial function after intratemporal facial nerve reconstruction using interposition nerve graft would provide useful information for clinicians to understand the regenerative process of the facial nerve after this type of surgery. It would also enable them to obtain informed consent from the patients by preoperatively explaining the predicted outcome of the postoperative facial paralysis. Objective. The purpose of this study was to describe the recovery course of facial movement and electrophysiological findings after intratemporal facial nerve reconstruction using interposition graft. Patients and methods. Five patients who underwent reconstruction of the facial nerve using interposition nerve graft immediately after facial nerve excision during surgery for temporal bone lesions were included in this study. Each patient was evaluated for facial movement (Yanagihara score), blink reflex (BR), and electroneurography (ENoG) preoperatively and postoperatively. Results. Improvement in facial movement began 8-10 months postoperatively. The score then gradually increased, and reached a plateau level by 2 years following surgery. The final score in four of the five patients ranged from 20 to 24 points, while the facial score of one patient only reached 12 points even at 3 years after surgery. All patients demonstrated moderate to severe synkinesis. The reappearance of R1 in BR occurred 7-10 months postoperatively, almost simultaneously with the beginning of recovery of facial movement. The latency of R1 on the operated side became shortened with increasing postoperative time, although it remained considerably longer than that on the unoperated side, even after 2 postoperative years. The onset of recovery of ENoG value (10-12 months postoperatively) was always delayed compared with the actual facial movement recovery and never returned to the level in the unoperated side. [ABSTRACT FROM AUTHOR]

Conclusion. The present study demonstrated the age-related decrease in the axonal diameter of the olfactory nerve. This finding may represent the maturational change of the olfactory receptor neurons. Objectives. The aim of this study was to investigate age-related changes in the axonal diameter of the olfactory nerve in the lamina propria. Materials and methods. Female ICR mice, postnatal age 10 days, 3 months, 7 months, and 16 months, were studied. The electron micrographs of septal olfactory mucosa were used to measure the axonal diameters of olfactory nerves. Results. The distribution of the diameter shifted toward the thinner side between 10-day-old and 3-month-old mice. The axonal diameter showed significant decreases (p < 0.001) from the age of 10 days to that of 3 months. [ABSTRACT FROM AUTHOR]

Conclusion. This study suggested that nitric oxide (NO) takes part in the parasympathetic nerve control functions mainly through m3 receptors and subsequently through m1 receptors. Objectives. The regulation of glandular secretions and vasomotor tone in human nasal mucosa implicates muscarinic receptors. There are five recognized classes (m1-m5) of muscarinic receptor subtypes. NO is a free radical gas that has been found to be produced in neuronal cells by the action of enzyme neural nitric oxide synthase (nNOS). The aim of this study was to identify the colocalization of muscarinic receptor subtypes (m1-m5) and nNOS in the human inferior turbinate mucosa. Materials and methods. Human inferior turbinate mucosa was stained by using the antibody of muscarine receptor subtypes and nNOS in an immunohistochemical double-staining method. Results. The colocalization of m3 receptors and nNOS-immunoreactive nerve fibers was most extensively distributed on glands, vessels, and epithelium in all muscarinic receptor subtypes. These findings lead us to propose that NO also acts as a neurotransmitter in glands, vessels, and epithelium of the human nasal mucosa and can be assigned to parasympathetic nerve structures through m3 receptors mainly and m1 receptors subsequently. [ABSTRACT FROM AUTHOR]

We report a case in which metastasis occurred from a left-side maxillary carcinoma to bilateral temporal bones through different routes, manifested by rapidly progressing left-side mixed hearing loss, left-side vestibular dysfunction, and serous otitis media. Later the left-side hearing threshold became severely elevated, suggesting profound sensory hearing loss. Histopathology of the temporal bones revealed that the side with the lesion was severely damaged by tumor through direct and hematogenous metastasis. On the contralateral side, it showed four findings: (i) sparse and separate tumor invasion of the petrous bone, the mastoid cavity, and the facial canal (hematogenous spread); (ii) tumor involvement in the lower part of the cochlear aqueduct without invasion of the internal acoustic canal or cochlea, implying early meningeal carcinomatosis; (iii) vascular stria atrophy, spiral ganglion diminution, and well preserved hair cells; and (iv) diffuse effusion in the middle ear and mastoid cavity. Our observations revealed that tumor cells dispersed to the same side through different routes, whereas early metastasis to the contralateral side was mainly through hematogenous and subarachnoid spread. [ABSTRACT FROM AUTHOR]

Conclusion These results suggest that COX-2 and bcl-2 protein were overexpressed and that apoptosis was reduced in MEC compared to PMA, and that COX-2 may regulate the degree of apoptosis by modulating bcl-2 protein in PMA and MEC. Objective Cyclooxygenase (COX)-2 plays a crucial role in tumorigenesis and overexpression of COX-2 in vitro accompanied by overexpression of bcl-2 protein has been shown to reduce apoptosis. The purpose of this study was to verify that COX-2 regulates the degree of apoptosis by modulating bcl-2 protein in benign and malignant parotid gland tumors. Material and methods We examined archival formalin-fixed, paraffin-embedded tissue sections of 10 pleomorphic adenomas (PMAs) and 10 mucoepidermoid carcinomas (MECs) by immunostaining with anti-COX-2, anti-bcl-2 and anti-single-stranded DNA (ssDNA) antibodies. Labeling indices of the three antibodies were calculated using computer-assisted image analysis. Results Labeling indices (mean&PlusMinus;SD) of anti-COX-2 antibody in PMA and MEC were 2.05&PlusMinus;1.30 and 11.2&PlusMinus;2.95, respectively ( p <0.001), those of anti-bcl-2 antibody were 2.00&PlusMinus;1.28 and 9.68&PlusMinus;4.05, respectively ( p <0.001) and those of anti-ssDNA antibody were 8.06&PlusMinus;2.54 and 2.08&PlusMinus;1.47, respectively ( p <0.001). Correlation coefficients between the labeling indices of anti-COX-2 antibody and anti-bcl-2 antibody, anti-bcl-2 antibody and anti-ssDNA antibody and anti-COX-2 antibody and anti-ssDNA antibody were 0.88, -0.75 and -0.76, respectively ( p <0.001). [ABSTRACT FROM AUTHOR]

In a previous study we showed that, in rat spiral ganglion neurons (SGNs), the adenosine 5'-triphosphate (ATP)-evoked currents were a combination of the activation of ionotropic receptors (the first fast current) and the activation of metabotropic receptors which secondarily opened non-selective cation channels. These two conductances imply the involvement of different receptor subtypes. In the present study, we tested three subtype-specific purinergic ligands: α,β-methylene ATP (α,β-meATP) for P2X receptors, uridine 5′-triphosphate (UTP) for P2Y receptors and 2′-3′-O-(4-benzoylbenzoyl) ATP (Bz-ATP) for P2Z (P2X 7 ) receptors. Application of 100 μM α,β-meATP did not trigger any significant change in membrane conductance, while the SGNs were responsive to ATP. Pressure application of UTP (100 μM, 1 s) evoked an inward current averaging 344±169 pA at a holding potential of -50 mV. The conductance developed after a latency averaging 1.5±0.6 s, took 4-6 s to peak and reversed slowly within 15-30 s. The current-voltage curve reversed near 0 mV, suggesting a non-selective cation conductance, like the second component of the ATP conductance. Bz-ATP evoked an inward current which developed without latency, was sustained during ligand application and was rapidly inactivated at the end of application: the same characteristics as the first component of the ATP-evoked current. The Bz-ATP conductance reversed around -10 mV, indicating also a non-selective cation conductance. These results suggest that, in SGNs, ATP acts via two different receptor subtypes, ionotropic P2Z receptors and metabotropic P2Y receptors, and that these two receptor subtypes can assume different physiological roles. [ABSTRACT FROM AUTHOR]

Background: A diagnostic indicator for differentiating squamous cell carcinomas (SCCs) from inverted papillomas (IPs) has not been established. Objectives: This study aimed to evaluate whether CT attenuation values relative to those of the brainstem (relative CT number) could be useful in differentiating IPs from SCCs. Material and Methods: Consecutive patients who were pathologically diagnosed with IP or SCC between 2007 and 2017 were retrospectively identified. Relative CT numbers were compared between the two patient groups. The factors with predictive power for differentiating IPs from SCCs were identified by univariate and multivariate logistic regression analyses. Results: Fifty-four sinonasal tumour cases were finally analysed (IP, 25 cases; SCC, 29 cases). Relative CT numbers were significantly higher in SCC than in IP (p <.001). The univariate logistic regression analysis showed BMI, relative CT number, and disease duration to have predictive value for differentiating IPs from SCCs. In the multivariate logistic regression analysis, only the relative CT number had predictive value for distinguishing IP from SCC (odds ratio, 1.97), with a relative CT number of ≥1.4 being significantly associated with SCC. Conclusions: High relative CT numbers could potentially be used to identify SCCs, and their measurement could provide a basis for differentiating IPs from SCCs. [ABSTRACT FROM AUTHOR]

Objective: There has been little progress in examination of the oropharynx with a light source such as electric light, a penlight, or a forehead mirror over the past 100 years. It is therefore necessary to develop methods to display and record oropharyngeal observations. Method: Since the aim of this study was to assess the safeness to use from the perspective of physicians, medical staffs, patients, and patients’ families and usefulness of pharyngeal scope, the number of devices was limited, the number of patients was not set based on hypothetical statistical tests. Results: A total of 150 volunteers were enrolled in this study. Among them, 96 underwent examination alone and the remaining 28 underwent treatment procedures. The study was done without any complications in all 150 cases. Most (91.3%) physicians hoped to continue using the new device if available. When comparing the use of the device for observation alone and for treatment procedures, there was no significant difference for evaluation items (p > .05) except convenience factor which received a significantly different (p = .0154) evaluation from physicians for observation alone and for treatment procedures. A positive evaluation was received about examination, recording/display and explanation from the patients and patients’ families. Conclusions: Our new device received positive evaluations by who underwent examination of the oral cavity and pharynx, recording of the results, and treatment procedures. [ABSTRACT FROM AUTHOR]

Conclusion: This cohort study showed that onset latency in the intravenous olfactory test (IVO) may help predict when olfaction in patients with post-infectious olfactory dysfunction (PIOD) improves. Objectives: To identify factors that predict the olfactory improvement period in patients with PIOD. Methodology/Principal: All consecutive patients presenting with PIOD in 1994–2014 who were followed up for 2 years were identified retrospectively. The ability of demographic/clinical factors (age, sex, body mass index, presence/absence of allergic rhinitis, treatment/non-treatment with herbal medicines, patient dependence on herbal medicine treatment, presence/absence of diabetes mellitus, and smoking status) and olfactory test factors (response/no response and onset latency and duration in the IVO test, and detection and recognition scores on the T&T olfactory test) to predict the olfactory improvement period (defined respectively as the time from PIOD onset or olfactory testing to the first self-report of olfaction improvement) was analyzed by univariate and multivariate regression. Results: Of the 187 PIOD patients, the prognostic ability of demographic/clinical factors was analyzed in 65. None predicted the olfactory improvement period. Of the 65 patients, 20 did not respond in the IVO test. In the remaining 45 patients, onset latency (but not the other olfactory test factors) was a significant prognosticator of olfactory improvement period (R2=0.24, p = 0.003). [ABSTRACT FROM AUTHOR]

Conclusion: Polymer-coated electrodes can reduce surgically-induced trauma associated with the insertion of a cochlear implant (CI) electrode array. Objectives: To evaluate if insertion trauma in CI surgery can be reduced by using electrode arrays coated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. Methods: We analyzed characteristics of the Contour Advance® electrode arrays coated with MPC polymer. To assess surgical trauma during electrode insertion, polymer-coated or uncoated (n = 5 each) animal electrode arrays were implanted in guinea pig cochleae and operability and electrophysiological and histological changes were assessed. Results: Under light and scanning electron microscopy, polymer-coated electrodes did not appear different from uncoated electrodes, and no change was observed after mechanical stressing of the arrays. Electrode insertion was significantly easier when polymer-coated electrodes were used. Auditory brainstem response (ABR) thresholds did not differ between groups, but p1-n1 amplitudes of the coated group were larger compared with the uncoated group at 32 kHz at 28 days after surgery. The survival of outer hair cells and spiral ganglion cells was significantly greater in the polymer-coated group. [ABSTRACT FROM AUTHOR]

In 1999, three workers received high doses of radiation in a small Japanese plant while they were preparing fuel for an experimental reactor. This criticality accident at melting point was caused by the addition of too much uranium enriched to a relatively high level, causing a ''criticality'' (a limited uncontrolled nuclear chain reaction), which continued intermittently for 20 h. The three workers concerned were hospitalized, two in a critical condition. The first worker died 12 weeks later, and the second worker 7 months later. The third worker is in a healthy condition. We report on the temporal bone histopathological features of the second worker. Our temporal bone study revealed: 1) the large loss of bone marrow tissue with a small number of myelocytes remaining in the mastoid bone and the abundance of fatty tissue in the mastoid bone, 2) inflammation of the mucosal layer of the middle ear and the mastoid air cells, 3) mild degeneration of the spiral ganglions and the sensory hair cells of the cochlea, 4) mild degenerative changes of sensory hair cells of the semicircular canals and otolith organs, and 5) vestibular ganglions and geniculate ganglions were well preserved. [ABSTRACT FROM AUTHOR]

We have developed a special purpose adaptor making it possible to use a commercially available high-speed camera to observe vocal fold vibrations during phonation. The camera can capture dynamic digital images at speeds of 600 or 1200 frames per second. The adaptor is equipped with a universal-type attachment and can be used with most endoscopes sold by various manufacturers. Satisfactory images can be obtained with a rigid laryngoscope even with the standard light source. The total weight of the adaptor and camera (including battery) is only 1010 g. The new system comprising the high-speed camera and the new adaptor can be purchased for about $3000 (US), while the least expensive stroboscope costs about 10 times that price, and a high-performance high-speed imaging system may cost 100 times as much. Therefore the system is both cost-effective and useful in the outpatient clinic or casualty setting, on house calls, and for the purpose of student or patient education. [ABSTRACT FROM AUTHOR]