Clinical and audiologic characteristics of patients with sensorineural tinnitus and its association with psychological aspects: an analytic retrospective study.

This study was performed to analyze clinical and audiologic characteristics of sensorineural tinnitus and to investigate the associating factors reflecting psychological aspects of stress and depression of the patients. This is a retrospective analytical study conducted in a tinnitus clinic of a tertiary referral center of a university hospital. The medical records of 216 patients suffering from sensorineural tinnitus were thoroughly evaluated to determine correlations between clinical and audiological characteristics, including age, sex, predisposing or etiologic factors, hearing levels up to extended high frequencies, and tinnitus severity. Psychological aspects of stress and depression were also evaluated and analyzed to seek the associations with tinnitus severity. All data were stored in our database bank and were statistically analyzed. Our study subjects showed a slight male predominance. The highest percentage of tinnitus was found in patients of 60-80 years old. Only 32.5 % of tinnitus patients were subjectively aware of their hearing loss, whereas 73 % of subjects had hearing deficits in some frequencies in their audiogram. Hearing impairments were of the low-frequency sensorineural type in 18.2 % of patients and were limited to the high frequencies in 77.9 % of patients. Tinnitus was unilateral in 51 % of patients and had a tonal nature in 45 % of patients. In total, 45.8 % of patients with high-frequency sensorineural hearing loss had high-pitched tinnitus. There were significant correlations between tinnitus severity, loudness and annoyance. Correlations with THI (Tinnitus Handicap Inventory) and Beck depression index scores were also found. Sensorineural tinnitus was related with hearing loss in some frequencies nevertheless of patients' own awareness of hearing loss. Loudness and annoyance of tinnitus seems to be two important factors reflecting psychological problems of patients' stress and depression.

Predictors for outcome of paper patch myringoplasty in patients with chronic tympanic membrane perforations.

The purpose of the present study is to evaluate the outcome of paper patch myringoplasty for chronic tympanic membrane (TM) perforations and to explore the predictive factors for a successful closure. A retrospective study was performed in a tertiary referral center. Data of the patients who met the inclusion criteria were analyzed: the treatment outcomes and the potential predictive factors including age, sex, the affected ear, hearing level, duration of perforation, causes, location and size of perforations, relationship between the perforation border and the malleus, status of TM surface, and the number of patch applications. Complete closure was achieved in 27 of the total 43 subjects. Among the 11 clinical and TM factors, only the perforation size remained significant as the predictor after multivariable logistic regression (p = 0.029, OR 4.4). The patients with perforation ≤ 5% of the TM showed higher closure rate (78.3%) than those with perforation >5% (45.0%). In conclusion, paper patch myringoplasty showed overall success rate of 62.8%. In patients with perforations smaller than 5% of the TM, the closure rate was 78.3%. The predictor of the treatment outcome was the perforation size. We can try paper patch myringoplasty first in patients who had dry chronic perforations smaller than 5% of the TM without middle ear disease.

Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons.

During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia-NCAMs) modulate cell-cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia-NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb's to polySia, NCAM, ß-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell-cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.

Anoctamin 1 expression in the mouse auditory brainstem.

Calcium-activated chloride channels (CaCCs) are involved in numerous physiological functions, including the epithelial movement of fluid. Anoctamin 1 (ANO1) has recently been cloned and characterized as a CaCC and is known to be expressed in various secretory epithelia and in nervous tissues such as the dorsal root ganglia and retina. However, data regarding the expression, function, and cellular and subcellular localization of CaCCs in the brain are still limited. We investigated the distribution and expression patterns of ANO1 in adult mouse brain. Reverse transcriptase plus the polymerase chain reaction, Western blot, and immunohistochemical analyses demonstrated that ANO1 was widely distributed throughout the brain. Furthermore, ANO1 was strongly expressed in two auditory brainstem nuclei: the medial nucleus of the trapezoid body (MNTB) and the anteroventral cochlear nucleus (AVCN). Double-labeling experiments revealed that this ANO1 expression was exclusive to the presynaptic endings of both the MNTB and AVCN. ANO1 is thus mainly localized at presynaptic terminals in various brain regions, specifically in two auditory brainstem nuclei, the MNTB and AVCN, and might therefore contribute to the high-frequency synaptic transmission of auditory signals.

Childhood tinnitus: clinical characteristics and treatment.

PURPOSE: Troublesome tinnitus in children can have an impact on their lives leading to behavioral or psychological problems. The present study was designed to identify the clinical features of childhood tinnitus, to establish the treatment strategy for each tinnitus category and severity, and to assess the treatment outcomes. MATERIALS AND METHODS: Clinical data were retrospectively collected on 108 tinnitus patients in childhood and adolescence. The authors have classified tinnitus according to the acoustic source: otic (idiopathic subjective), myoclonic, and vascular tinnitus based on the tinnitus quality and appropriate diagnostic approaches. Treatment selection depended on the tinnitus category and severity. Treatment modalities included counseling, a simplified tinnitus retraining therapy, counseling with medications, and surgery. RESULTS: Of all 108 subjects, otic tinnitus was the most common form of childhood tinnitus (n=80) followed by myoclonic (n=21) and vascular tinnitus (n=6). The prevalence of otic tinnitus increased with age. The mean age of myoclonic tinnitus patients was younger than that of the others. The majority of otic tinnitus showed normal hearing. The origin of 81% of myoclonic tinnitus was middle ear muscles. Of all subjects, 67.6% had mild tinnitus responsive to counseling alone. Distressing tinnitus was most common in myoclonic tinnitus. Almost all patients (97%) who were followed up at 3 months (64%) showed improvements. CONCLUSIONS: We suggest that understanding the clinical characteristics of childhood tinnitus, establishing a diagnosis based on the acoustic source, and implementing appropriate therapy customized to the individual tinnitus category and severity would help clinicians to relieve tinnitus children of their troublesome tinnitus effectively.

Diagnostic value and clinical significance of stress hormones in patients with tinnitus.

Tinnitus has been found to be modulated by stress and is also closely related to the emotional state and the limbic system. In the present study, we evaluated the diagnostic and clinical values of several stress hormones in a large number of tinnitus patients. This study included 344 patients with sensorineural tinnitus and 87 normal controls. A questionnaire about tinnitus was administered to the participants, and blood levels of norepinephrine (NE), epinephrine (Epi), a metabolite of serotonin (5-hydroxyindoleacetic acid, 5-HIAA) and cortisol were compared between groups. In results, the mean values of Beck's depression inventory (BDI), Brief Encounter Psychosocial Instrument (BEPSI), NE, and 5-HIAA levels were higher in the tinnitus group, although there was no statistical significance. But, the proportion of participants with elevated 5-HIAA was significantly higher in the tinnitus group (21.8 vs. 8.0 %, P < 0.05), and the 5-HIAA level significantly correlated with the duration of tinnitus, NE and cortisol. Elevated stress-related hormones, as well as hearing loss, BDI, and BEPSI were the most related factors with tinnitus in multiple regression test with age adjustment. However, levels of stress-related hormones did not correlate with subjective measures including BDI, BEPSI and severity of tinnitus. In conclusion, blood stress hormones seemed to have some diagnostic and clinical value in patients with tinnitus, and serotonin is supposed to be the most important hormone in tinnitus. Further studies about the values of stress and stress hormones in tinnitus patients may lead to new approaches regarding diagnosis and clinical management of the disease.

Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model.

The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

Renexin as a rescue regimen for noise-induced hearing loss.

Renexin, a compound of cilostazol and ginkgo biloba extract, has been reported to produce neuroprotective effects through antioxidant, antiplatelet, and vasodilatory mechanisms. This study was designed to investigate the protective effects of renexin on hearing, the organ of Corti (OC), and medial olivocochlear efferents against noise-induced damage. C57BL/6 mice were exposed to 110 dB SPL white noise for 60 min and then randomly divided into three groups: high- and low-dose renexin-treated groups and noise only group. Renexin were administered for 7 days: 90 mg/kg to the low-dose, and 180 mg/kg to the high-dose groups. All mice, including the controls underwent hearing tests on postnoise day 8 and were killed for cochlear harvest. We compared the hearing thresholds and morphology of the OC and cochlear efferents across the groups. The renexin-treated groups recovered from the immediate threshold shifts in a dose-dependent manner, while the noise group showed a permanent hearing loss. The renexin-treated ears demonstrated less degeneration of the OC. The diameters of the efferent terminals labeled with α-synuclein were preserved in the high-dose renexin-treated group. In the western blot assay of the cochlear homogenates, the treated groups displayed stronger expressions of α-synuclein than the noise and control groups, which may indicate that noise-induced enhanced activity of the cochlear efferent system was protected by renexin. Our results suggest that pharmacologic treatment with renexin is hopeful to reduce or prevent noise-induced hearing loss as a rescue regimen after noise exposure.

Tinnitus in patients with profound hearing loss and the effect of cochlear implantation.

The objectives of this study were to characterize the features of tinnitus in patients with profound sensorineural hearing loss and to evaluate the effect of cochlear implantation (CI) on their tinnitus. Medical records were reviewed for 35 patients who underwent CI, and completed tinnitus questionnaire between March 2003 and August 2011. Of them, 22 had tinnitus prior to CI (62.9 %) and the tinnitus group was older than the non-tinnitus group (47.5 ± 15.1 vs. 28.9 ± 15.2). The mean tinnitus handicap inventory (THI) score of the tinnitus group was 50.5 ± 28.7 before surgery, and the mean THI score and visual analogue scale (VAS) scores for loudness, annoyance, effect on life, and awareness decreased significantly after CI, with a mean follow-up period of 10.7 months. Tinnitus was completely eliminated in ten patients (45.5 %) and THI scores decreased in all patients. In a correlation analysis of the decrease in THI scores, preoperative VAS scores for loudness, awareness, effect on life, and annoyance, as well as preoperative THI scores, were highly correlated with the degree of decrease in THI scores postoperatively. The auditory performance of patients older than 40 years did not differ from that of younger patients, but their tinnitus was more improved after CI. In conclusion, tinnitus is a common complaint in patients with cochlear implants, and is more prevalent in elderly implantees. In the present study, CI improved tinnitus in all patients, although the most severe cases had the greatest benefit.

Hearing restoration in a deaf animal model with intravenous transplantation of mesenchymal stem cells derived from human umbilical cord blood.

OBJECTIVE: This study was performed to confirm the effect of transplantation of human umbilical cord blood mesenchymal stem cells (UCB-MSCs) on hearing restoration in a sensorineural hearing loss (SNHL) animal model. MATERIAL AND METHODS: UCB was collected from pregnant women after obtaining consent, and mesenchymal stem cells (MSCs) were extracted. We established an SNHL model and transplanted UCB-MSCs through the brachial vein of the guinea pigs. The animals were divided into 4 groups: animals with normal hearing, animals with SNHL, animals with SNHL and injected with saline, and animals with SNHL and transplanted with UCB-MSCs. Hearing tests were conducted at 1, 3, and 5 weeks, and the results were compared by grading auditory brainstem response (ABR) recordings and distortion product otoacoustic emissions (DPOAEs) for each treatment. Lastly, cochlear pathological features were examined, and surface preparations and morphological changes in each animal model were compared using hematoxylin and eosin staining and light microscopy studies. RESULTS: In SNHL group, decreased DPOAEs and increased ABR threshold were noted. Furthermore, in the SNHL group, ABR hearing thresholds were unconverted and were similar to those observed in deafness. The transplanted UCB-MSC group showed a significant improvement in hearing threshold (40 dB) compared to that in all the SNHL group (80-90 dB). Examination of the SNHL animals' cochlear morphological features demonstrated a noticeable lack of spiral ganglion cells and also showed degenerated outer hair cells. However, the transplanted UCB-MSCs showed an increase in spiral ganglion and hair cells. CONCLUSION: Intravenous transplantation of UCB-MSCs can enhance hearing thresholds, outer-hair cells and increase the number of spiral ganglion neurons (SGNs).

Preauricular sinus: advantage of the drainless minimal supra-auricular approach.

OBJECTIVES: We performed this study to introduce our minimal supra-auricular approach for the surgical management of a preauricular sinus (PAS) and to evaluate the advantages of this drainless technique. STUDY DESIGN: This was a retrospective study. SETTING: The study was done in a tertiary referral center. METHODS: We enrolled 94 patients (101 ears) with a PAS who underwent surgical treatment via a minimal supra-auricular approach performed by one surgeon between April 1999 and May 2010. After removing the specimen, meticulous subcutaneous suturing and no drain were used in 83 patients (89 ears) and a postoperative drain was inserted in 11 patients (12 ears). Surgical outcomes of this technique were compared between the groups with and without postoperative drain insertion. RESULTS: With a good surgical view and meticulous subcutaneous mattress sutures in our minimal supra-auricular approach for PAS excision, there was no postoperative recurrence or other serious complication. In the drain group, previous operation history was more frequent (P = .010), and the rate of preoperative infection was higher than in the drainless group (P = .018). Postoperatively, a compression dressing was required more frequently (P = .002) and for longer in the drain group (P = .001). The rate of immediate postoperative wound infection was higher in the drain group (P = .003). CONCLUSION: Our drainless minimal supra-auricular approach for the surgical removal of a PAS has advantage in terms of good surgical results of no recurrence and is more comfortable for patients because of the reduced need for a compression dressing. We suggest that this technique is effective and safe for PAS excision.

Expression and immunohistochemical localization of TMEM16A/anoctamin 1, a calcium-activated chloride channel in the mouse cochlea.

Sound transduction in the cochlea depends on the unique high concentrations of K(+) in the endolymph. The production and maintenance of high K(+) concentrations are accompanied by Cl(-) cycling. In this study, we report on an investigation of the expression and localization of TMEM16A/anoctamin 1 (ANO1), a recently cloned Ca(2+)-activated Cl(-) channel, in the mouse cochlea by Western blot and immunhistochemistry. The ANO1 protein was identified in the cochlea by Western blotting. The immunoreactivity was found in stria vascularis as a line and in the organ of Corti as three plaques. The cellular localization of ANO1 was examined by means of double-labeling experiments with anti-claudin 11, a marker for basal cells of the stria vascularis. The results demonstrated that ANO1 colocalized with claudin 11, indicating its expression in basal cells. We also examined ANO1 localization in the organ of Corti by double- and triple-labeling techniques with anti-myosin VI, a marker for hair cells, and anti-synaptophysin, a marker for olivocochlear efferent nerve endings under hair cells. The results clearly showed that ANO1 is colocalized with synaptophysin, but not with myosin VI, indicating that ANO1 is localized at medial olivocochlear efferent nerve endings under outer hair cells. These results suggest that ANO1 may be specifically involved in synaptic transmission from medial olivocochlear efferent nerve endings to outer hair cells in the organ of Corti, as well as Cl(-) cycling in basal cells of the stria vascularis.

Effects of a tumor necrosis factor-α antagonist on experimentally induced rhinosinusitis.

This prospective, randomized, and controlled study examined the effects of tumor necrosis factor soluble receptor type I (sTNFRI, a TNF-α antagonist) on experimentally induced rhinosinusitis in rats. The experimental groups received an instillation of lipopolysaccharide (LPS) plus an intramuscular injection of amoxicillin/clavulanate (antibiotic group), an instillation of sTNFRI (sTNFRI group), an instillation of sTNFRI and an injection of amoxicillin/clavulanate (sTNFRI/antibiotic group), or no additional treatment (LPS group). Histopathological changes were determined using hematoxylin-eosin and periodic acid-Schiff (PAS) staining. Leakage of exudate was determined using fluorescence microscopy. Vascular permeability was measured using the Evans blue dye technique. Expression of MUC5AC was measured using reverse transcriptase PCR. The sTNFRI, antibiotic, and sTNFRI/antibiotic groups had significantly less capillary permeability, mucosal edema, PAS staining, and expression of MUC5AC than the LPS group. There were no differences in capillary permeability, mucosal edema, PAS staining, and MUC5AC expression between the sTNFRI and sTNFRI/antibiotic groups. The antibiotic group had PAS staining similar to that of the sTNFRI and sTNFRI/antibiotic groups but had a greater increase in capillary permeability, mucosal edema, and MUC5AC expression. This study shows that sTNFRI reduces inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats.

Prevalence and significance of high-frequency hearing loss in subjectively normal-hearing patients with tinnitus.

OBJECTIVES: We investigated the incidences of high-frequency hearing loss (HFHL; above 2 kHz) and extended high-frequency hearing loss (EHFHL; above 8 kHz) in patients with tinnitus and subjectively normal hearing, and evaluated their effects on the clinical and audiological features of the patients. METHODS: The sample included 85 patients with sensorineural tinnitus who had normal hearing sensitivity in the frequencies from 250 Hz to 2 kHz, and who had undergone extended high-frequency audiometry between July 2009 and February 2010. We investigated the incidences of HFHL and EHFHL in these patients and analyzed the significance of the hearing losses. RESULTS: The incidence of HFHL or EHFHL was 88%. The proportion of patients with EHFHL, among the patients who had normal hearing sensitivity up to 8 kHz, was about 74%. The patients with normal hearing sensitivity at all test frequencies were significantly younger, had larger otoacoustic emissions, and had tinnitus that was less loud as measured by tinnitus matching than did the subjects with HFHL and/or EHFHL. However, other comparisons of clinical factors in the three groups did not show any differences. CONCLUSIONS: Even if patients with tinnitus do not have any subjective hearing impairment, most of them have HFHL and/or EHFHL. The effects on the clinical features of the patients are still vague.

Tinnitus in patients with chronic otitis media before and after middle ear surgery.

The objective of this study was to investigate the clinical features of tinnitus in patients with chronic otitis media (COM) and to evaluate changes in tinnitus following middle ear surgery in relation to audiologic outcome. Medical records were reviewed for 117 patients with COM who underwent middle ear surgery between March 2009 and March 2010. Of them, 44 patients who pre-operatively reported tinnitus on a tinnitus questionnaire and 28 patients who completed a tinnitus questionnaire 8 weeks after surgery were evaluated to determine the clinical characteristics of tinnitus in patients with COM and any change in tinnitus following middle ear surgery, respectively. New tinnitus symptoms that developed after surgery were also evaluated in previously asymptomatic patients. The pre-operative incidence of tinnitus in patients with COM was 43% (50/117), with 87% of these patients displaying sensorineural tinnitus. After middle ear surgery, tinnitus handicap inventory scores were reduced in 82% of patients (23/28). Mean values of loudness, annoyance, effect on life, and awareness of tinnitus were also significantly reduced. One patient displayed newly developed tinnitus after surgery. Analysis of the relationship between improvement in tinnitus and audiologic outcome demonstrated that the group of patients whose tinnitus handicap inventory was reduced by more than 10 showed significantly greater improvements in mean air-conduction thresholds than did patients in the other group. In conclusion, following middle ear surgery, most patients experienced a reduction in tinnitus and restored hearing, with surgery perceived as an important contributory factor.

Solitary metastasis of bronchogenic adenocarcinoma to the internal auditory canal: a case report.

We report a patient with an isolated metastasis to the internal auditory canal (IAC) of bronchogenic adenocarcinoma. A 58-yr-old man who had received 6-cycle of chemotherapy under diagnosis of non-small cell lung carcinoma (T4N2M0) two years ago was referred to our department with vertigo, right-sided facial paralysis and right-sided hearing loss. A provisional diagnosis of vestibular schwannoma or meningioma involving right IAC was made from magnetic resonance imaging. The patient underwent a translabyrinthine removal of the tumor. Histopathological study of the resected lesion showed a poorly differentiated adenocarcinoma compatible with bronchogenic origin. The patient died 9 months after surgery from extensive brain metastasis despite postoperative radiation therapy. In patients with a previous history of treatment of malignancy elsewhere in the body, the possibility of IAC metastasis must be considered when an IAC lesion is detected.

Congenital middle ear cholesteatoma in children; retrospective review of 35 cases.

Congenital middle ear cholesteatoma (CMEC) is a rare disease entity in otolaryngology. However, we try to assess the characteristic features and recurrences of CMEC in pediatric patients according to stages, and to determine the value of preoperative computed tomography (CT) scan. Retrospective review of 35 cases of CMEC under the age of 15 yr that had been treated at the tertiary referral center from 1995 through 2006. The main outcome measures were CT findings, surgical findings, recurrence rate and hearing assessment. Preoperative CT scan accurately predicted the extent of the cholesteatoma seen during surgery in 30/35 (85.7%). The recurrence rate of CMEC was 5.7% (2/35) and all of recurred cases were stage IV. In recurred cases, cholesteatomas were extended to sinus tympani and facial recess at revisional operation as well as initial operation. So we concluded that preoperative CT scan is essential in defining the extent of existing pathology. The intraoperative CMEC extension and location influence the outcome of surgery. In the higher stages, careful eradication of disease, particularly in the region of sinus tympani and facial recess is recommended.

Effect of infliximab on experimentally induced otitis media in rats.

OBJECTIVES: We performed a prospective randomized and controlled animal study to investigate the effects of infliximab on experimental otitis media in rats. METHODS: Seventy-two Sprague-Dawley rats were randomly allocated to 3 study groups and 1 control group. Infliximab was injected intravenously. Histopathologic changes were determined by hematoxylin-eosin staining. Fluorescence microscopy was performed to examine the leakage of the exudates. Vascular permeability was measured by the Evans blue dye technique. RESULTS: In comparison with the control group, we found significant differences in the extent of middle ear mucosa without active inflammation and the presence of reparable lesions in all study groups treated with infliximab. A significant reduction of extravasated Evans blue dye in all study group animals was found as compared with the control group animals. CONCLUSIONS: This study suggests that the monoclonal tumor necrosis factor alpha antibody, infliximab, can reduce inflammatory activity in experimental otitis media in rats.

Cognitive decline and increased hippocampal p-tau expression in mice with hearing loss.

Hearing and cognition are commonly involved in both normal and pathological aging. Current clinical interest lies in whether peripheral hearing loss promotes cognitive decline. In our previous publication, the authors have shown a causal relationship between hearing and cognitive impairments in C57BL/6 mice. Here we extended the follow-up to 12 months to determine the long-term effects of hearing loss on cognition and to observe hippocampal p-tau and lipofuscin. One month old male mice were randomly allocated into two groups, the control (n = 12) and noise-induced hearing loss (NIHL) (n = 12). After baseline hearing and cognitive measurements, the mice in the NIHL group were exposed to 110 dB SPL white noise for 1 h every day for 20 consecutive days. Cognitive function was assessed by radial arm maze and novel object recognition tests. p-Tau was observed by the western blot, immunofluorescence, and immunogold staining. The mice in the NIHL group showed elevated auditory brainstem response thresholds and poorer performances in spatial working and recognition memories than the controls. They exhibited more p-tau and lipofuscin in the hippocampus. The cognitive impact of hearing loss varied with the types of memory. Working memory impairment was reversible, whereas recognition memory impairment was permanent. Our results provide behavioral and histopathological evidence for hearing-related cognitive decline. Early hearing loss is suggested to be one of the important determinants between normal and pathological cognitive aging.

The effect of Bacillus Calmette-Guerin in a mouse model of allergic rhinitis.

OBJECTIVE: To develop an allergic rhinitis model via local sensitization of mice with Dermatophagoides pteronyssinus and to use the model to investigate the antiallergic effect of Bacillus Calmette-Guerin (BCG). METHODS: BALB/c mice were randomized to the allergic rhinitis group, the BCG group sensitized with D pteronyssinus via local sensitization for 7 weeks, or the control group. The BCG group received 1 x 10(5) colony-forming unit/mL of BCG seven times. We evaluated symptoms, nasal mucosa eosinophilia, serum total IgE, cytokines, and eosinophilia in bronchoalveolar lavage fluid. RESULTS: In the allergic rhinitis group, allergy symptoms (P < 0.001), eosinophil count (P < 0.001), total IgE (P < 0.001), inflammatory cells (P < 0.01), and IL-13 (P = 0.046) increased and interferon gamma (IFN-gamma) (P < 0.001) decreased compared with the control group. In the BCG group, allergy symptoms (P < 0.001), eosinophil count (P < 0.001), and inflammatory cells (P < 0.01) decreased and IFN-gamma (P = 0.031) increased compared with the allergic rhinitis group. CONCLUSION: In an allergic rhinitis animal model developed via local sensitization of mice with D pteronyssinus, BCG was shown to exhibit an antiallergic effect.