Improvement of vertigo symptoms and acoustic power absorbance in cases with endolymphatic hydrops.

Objective: The pathophysiology and symptoms underlying Meniere's disease (MD) manifest as endolymphatic hydrops (EH), potentially impacting acoustic power absorbance in vestibular EH. The longitudinal effects of middle ear pressure therapy (MEPT) and conservative therapies for EH by magnetic resonance imaging (MRI) and on acoustic power absorbance on wideband acoustic immittance (WAI) were evaluated, and their changes were compared with clinical symptoms. Methods: Eleven patients with definite MD or delayed endolymphatic hydrops (DEH), resistant to conservative therapies and who continued MEPT for 1 year, were included. Vertigo scores, hearing levels, acoustic power absorbance on WAI, and degrees of EH on 3-T MRI were evaluated and compared before and after the treatments. Results: One year after the start of MEPT, all cases showed symptomatic improvement in vertigo score; however, the degrees of EH showed no improvements except in one case. In the affected ears with EH, their absorbances on WAI improved, particularly at 1580-1905 or 2400-2953 Hz (p < .05). Conclusion: Alleviation of vestibular symptoms with the therapy of MD was not necessarily associated with improved EH. Vestibular symptoms could be related to the change in the impedance of inner ear pressure, which was proven by the normalization of acoustic power absorbance. Assessments of acoustic power absorbance may provide useful information for physiological conditions and causative factors of vertigo in ears with EH. Level of evidence: 4.

Comparative Analysis of Cartilage Conduction Hearing Aid Users and Non-Users: An Investigative Study.

Clinical findings on cartilage conduction hearing aids (CCHAs) have gradually become clear; however, few reports include a large number of cases. This study included 91 ears from 69 patients who underwent CCHA fitting in our hospital. Their ears were divided into six groups (i.e., bilateral aural atresia or severe canal stenosis, unilateral aural atresia or severe canal stenosis, chronic otitis media or chronic otitis externa with otorrhea, sensorineural hearing loss, mixed hearing loss, and conductive hearing loss) according to their clinical diagnosis and type of hearing loss. Most clinical diagnoses were aural atresia or meatal stenosis (bilateral, 21.8%; unilateral, 39.6%). The purchase rate of CCHAs was higher in the closed-ear group (bilateral, 77.3%; unilateral, 62.5%). In the bilateral closed-ear group, air conduction thresholds at 1000, 2000, and 4000 Hz and aided thresholds with CCHAs at 4000 Hz were significantly lower in the purchase group than the non-purchase group. No significant difference was observed between the purchase and non-purchase groups in the unilateral closed-ear group. In the bilateral closed-ear group, air conduction thresholds and aided thresholds were associated with the purchase rate of CCHAs. In the unilateral closed-ear group, factors other than hearing might have affected the purchase rate of CCHAs.

Evaluation of the Listening Environment of Bilateral Cochlear Implant Users through Data Logging: A Comparison of Bilateral Simultaneous and Sequential Implantation.

OBJECTIVE: To evaluate the listening conditions of bilateral cochlear implant (CI) users in their daily living environment. STUDY DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: Thirty-one adult CI users 16 years or older; 18 underwent sequential surgery, and 13 underwent simultaneous surgery. Inclusion criteria included the availability of CI data logging features and a minimum duration of binaural use of 6 months. INTERVENTION: Retrospective analysis of data obtained from the automatic scene classifier data logging system. MAIN OUTCOME MEASURE: Comparison of data logging and maximum speech discrimination scores of the two surgery groups (sequential vs. simultaneous) to investigate the potential influence of these factors on the listening conditions of CI users. RESULTS: The maximum speech discrimination score of the second CI in the sequential group was significantly worse than that of any other CI in the sequential and simultaneous CI groups. Additionally, the longer the interval between surgeries, the more significant the difference in "time on air" between the first and the second CIs. The second CI in sequential CI surgery had a shorter "time on air" than the first or the bilateral simultaneous CIs; the second CI was also used more frequently in noisy and speech with background noise environments. CONCLUSIONS: A second CI may be more frequently used in challenging listening environments because of its binaural auditory effect, despite its lower speech discrimination performance. The timing of sequential implantation and the potential impact of binaural hearing should be considered when developing rehabilitation strategies for individuals with bilateral CIs.

Presence of endolymphatic hydrops on listening difficulties in patients with normal hearing level.

BACKGROUND: Listening difficulties (LiD) present difficulties in listening and paying attention to spoken information despite normal pure tone audiometry. Endolymphatic hydrops (EH) is a common inner ear condition associated with Ménière's disease but may also be present in the asymptomatic ear. OBJECTIVES: Using magnetic resonance imaging, we investigated EH in patients with LiD and assessed whether the severity of EH was related to the results of auditory processing tests (APTs). MATERIALS AND METHODS: 111 patients with no abnormalities on pure tone audiometry, but displaying difficulties in listening, underwent evaluation through APTs and questionnaires. Upon obtaining informed consent, the inner ears of 20 consenting patients were evaluated utilizing a 3-Tesla magnetic resonance imaging. RESULTS: A higher percentage of patients diagnosed with LiD by APTs had significant EH in the cochlea and vestibule than in previously reported control cases. The percentage of correct answers in the speech-in-noise test was significantly lower in patients with than in those without significant EH. CONCLUSION AND SIGNIFICANCE: In this study, significant EH of the cochlea was associated with poor listening to noise. The presence of EH affects the functioning of the auditory processing system, even in ears that test normally on standard audiometric tests.

Impact of endolymphatic hydrops on DPOAE in subjects with normal to mild hearing loss.

Objective: The increased endolymph volume affects a shift in the organ of Corti and basilar membrane in ears with endolymphatic hydrops (EH), which might affect distortion-product otoacoustic emissions (DPOAE) by altering the operating point of the outer hair cells. We investigated how changes in DPOAE are related to the distribution site of EH. Study Design: Prospective study. Methods: Among 403 patients with hearing or vestibular symptoms who underwent contrast-enhanced magnetic resonance imaging (MRI) for the diagnosis of EH and subsequent DPOAE testing, subjects whose hearing levels on pure tone audiometry were ≤35 dB at all frequencies were included in this study. In patients with EH on MRI, the presence and amplitude of DPOAE were evaluated between groups with hearing levels of ≤25 dB at all frequencies versus hearing levels of >25 dB at one or more frequencies. Results: There were no differences in the distribution of EH between groups. The amplitude of DPOAE had no clear correlation with the presence of EH. However, in both groups, there was a significantly higher probability of the presence of a DPOAE response from 1001 to 6006 Hz in cases with EH in the cochlea. Conclusion: Among patients whose hearing levels were ≤35 dB at all frequencies, better responses on DPOAE testing were found in subjects with EH in the cochlea. Alteration of DPOAEs in the early stages of hearing impairment could indicate morphological changes in the inner ear with altered basilar membrane compliance due to EH. Level of Evidence: 4.

Idiopathic sudden sensorineural hearing loss in Japan.

CONCLUSION: An epidemiological survey of hospitals and private clinics in Japan regarding idiopathic sudden sensorineural hearing loss (SSNHL) revealed that the incidence of SSNHL was 60.9 per 100 000 population. There were more females than males in the younger generation. OBJECTIVE: The incidence of SSNHL varies largely by country. Because the Japanese criteria for diagnosing SSNHL have changed in accordance with those widely used in other parts of the world, a clinicoepidemiological study was undertaken using the new criteria. METHODS: Ehime, Aichi, and Iwate Prefectures were selected from the western, central, and northeastern regions of Japan, respectively. The subjects for this study were patients who suffered SSNHL between April 1, 2012 and March 31, 2013. Questionnaires were mailed to all hospitals and private clinics in which ENT doctors were working. Initial and final audiograms were requested for 10% of the patients. RESULTS: In all, 78 of 90 hospitals (87%) and 303 of 407 private clinics (74%) responded. It was reported that 1663 patients visited hospitals and 3090 patients visited only private clinics. It was estimated that 6205 SSNHL patients visited hospitals or private clinics in 1 year from a population of 10 145 000. Also, 23% of patients suffered acute low-tone SNHL (female to male ratio; 3:1 in definite cases).

Contributing factors to hearing of diabetic patients in an in-hospital education program.

CONCLUSION: In patients with poorly controlled diabetes mellitus (DM), hearing disturbance was associated with renal dysfunction and diabetic neuropathy, represented by decreases in median nerve compound action potential amplitude. METHODS: The evaluation was conducted using 43 subjects who were hospitalized for the purpose of DM education. The mean age was 58.1 years (range 21-82 years). The mean HbA1c was 9.5%. The mean DM duration was 11.0 years. Renal function, retina condition, and nerve conduction were evaluated in relation to DM complications (nephropathy, retinopathy, and neuropathy). Nerve conduction studies were used to obtain detailed information on the condition of the peripheral nerves. After otological inspection, pure-tone audiometry, auditory steady-state response (ASSR), and distortion-product otoacoustic emissions (DPOAEs) were measured. Stepwise multiple linear regression was used to analyze the results in the better ear and worse ear. RESULTS: Decreases in median nerve compound action potential amplitude were associated with deterioration in pure-tone audiometry and ASSR. Diabetic neuropathy, creatinine clearance, diabetic nephropathy, and retinopathy were related to hearing in ASSR and/or DPOAEs.

Development of vaccines and passive immunotherapy against SARS coronavirus using mouse and SCID-PBL/hu mouse models.

We have investigated novel vaccines strategies against severe acute respiratory syndrome (SARS) CoV infection using cDNA constructs encoding the structural antigens; spike (S), membrane (M), envelope (E), or nucleocapsid (N) protein, derived from SARS CoV (strain HKU39849, TW1, or FFM-1). As SARS-CoV is thought to infect the alveolar epithelial cell of the lung,in the present study, a type II alveolar epithelial cell clone, T7, was used to analyze the mechanism of CTL against SARS CoV membrane antigens. Mice vaccinated with SARS CoV (N) DNA or (M) DNA using pcDNA 3.1 (+) plasmid vector showed T-cell immune responses (CTL induction and proliferation) against type II alveolar epithelial cells (T7) transfected with SARS (N) or (M) DNA, respectively. To determine whether these DNA vaccines could induce T-cell immune responses in humans as well as in mice, SCID-PBL/hu mice were immunized with these DNA vaccines. PBL from healthy human volunteers were administered i.p. into IL-2 receptor gamma-chain-disrupted NOD-SCID mice [IL-2R(-/-) NOD-SCID]. SCID-PBL/hu mice thus constructed can be used to analyze the human immune response in vivo. The SCID-PBL/hu mice were immunized with SARS (N) DNA or (M) DNA and analyzed for a human T-cell immune response. The M DNA vaccine enhanced CTL activity and proliferation in the presence of M peptide in SCID-PBL/hu mice. Furthermore, the SARS N DNA vaccine induced CTL activity (IFN-gamma production by recombinant N protein or N protein-pulsed autologous B blast cells) and proliferation of spleen cells in SCID-PBL/hu mice. These results, demonstrate that SARS M and N DNA vaccines induced human CTL and human T-cell proliferative responses. On the other hand, we have developed SARS DNA vaccines that induce human neutralizing antibodies and human monoclonal antibodies against SARS CoV. Transgenic mice expressing SARS-CoV receptor (angiotensin converting enzyme 2) are also under development. These vaccines are expected to induce immune responses specific for SARS CoV in human and should provide useful tool for development of protective vaccines.

Novel recombinant BCG and DNA-vaccination against tuberculosis in a cynomolgus monkey model.

We have developed two novel tuberculosis (TB) vaccines: a DNA vaccine combination expressing mycobacterial heat shock protein 65 (Hsp65) and interleukin-12 (IL-12) by using the hemagglutinating virus of Japan (HVJ)-liposome (HSP65+IL-12/HVJ) and a recombinant BCG harboring the 72f fusion gene (72f rBCG). These vaccines provide remarkable protective efficacy in mouse and guinea pig models, as compared to the current by available BCG vaccine. In the present study, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis, to evaluate the HSP65+IL-12/HVJ and 72f rBCG vaccines. Vaccination with HSP65+IL-12/HVJ as well as 72f rBCG vaccines provided better protective efficacy as assessed by the Erythrocyte Sedimentation Rate, chest X-ray findings and immune responses than BCG. Most importantly, HSP65+IL-12/HVJ resulted in an increased survival for over a year. This is the first report of successful DNA vaccination and recombinant BCG vaccination against M. tuberculosis in the monkey model.

The development of vaccines against SARS corona virus in mice and SCID-PBL/hu mice.

We have investigated to develop novel vaccines against SARS CoV using cDNA constructs encoding the structural antigen; spike protein (S), membrane protein (M), envelope protein (E), or nucleocapsid (N) protein, derived from SARS CoV. Mice vaccinated with SARS-N or -M DNA using pcDNA 3.1(+) plasmid vector showed T cell immune responses (CTL induction and proliferation) against N or M protein, respectively. CTL responses were also detected to SARS DNA-transfected type II alveolar epithelial cells (T7 cell clone), which are thought to be initial target cells for SARS virus infection in human. To determine whether these DNA vaccines could induce T cell immune responses in humans as well as in mice, SCID-PBL/hu mice was immunized with these DNA vaccines. As expected, virus-specific CTL responses and T cell proliferation were induced from human T cells. SARS-N and SARS-M DNA vaccines and SCID-PBL/hu mouse model will be important in the development of protective vaccines.