Acta oto-laryngologica. Supplementum最新文献

Conclusion: This study demonstrated differential gene expression profiles along the axis of the mouse cochlea. It also suggests the mechanism that establishes the tonotopic organization.

Objectives: The molecular basis of the tonotopic mapping of the mammalian cochlea remains unclear. We therefore examined the genes that were abundantly expressed in either the apex or the base of mouse cochlea.

Materials and methods: Apical and basal portions of cochlea, which contained the organ of Corti and spiral ganglion neurons, were independently dissected from 10 adult C57BL/6 mice, and their total RNAs were respectively isolated. The gene expression profiles of each of these two pools were examined and compared to each other by the complementary DNA microarray technique.

Results: Of 20,289 probes tested, 64 genes were found to be expressed in the apical portion more than fivefold more abundantly than in the basal portion, and 77 genes were vice versa. Of interest, the genes of several functional proteins such as beta2- and gamma2-subunits of GABA(A) receptors dominated the basal part, indicating that these molecules may be involved in high-frequency tuning of the hair cells and/or ganglion neurons.

Conclusion: N1m growth indicates the differences in central auditory processing between bone-conducted ultrasound and air-conducted audible sound.

Objectives: Bone conduction enables ultrasound to be heard by the human ear. Despite many studies, the perceptual mechanism of bone-conducted ultrasound has not yet been clarified completely. Therefore, this study investigated the ultrasonic perception of humans, especially as regards the effects of stimulus intensity or loudness.

Subjects and methods: The effect of the stimulus level on N1m amplitude was measured over the psycho-acoustical dynamic range.

Results: The dynamic range for 30 kHz bone-conducted ultrasound (18.2 +/- 3.3 dB) was found to be significantly narrower than that for 1 kHz air-conducted sound (85.9 +/- 11.9 dB). As the stimulus level increased, the N1m amplitude in response to bone-conducted ultrasound grew faster than that to air-conducted sound. Although the growth of the N1m amplitude for air-conducted sound saturated below the uncomfortable loudness level (UCL), that for bone-conducted ultrasound continued to grow above the UCL.

Conclusion: This study showed that it is possible to transmit language information using bone-conducted ultrasound (BCU) in normal-hearing subjects. Our results suggest the possibility of a difference in speech recognition between BCU and air-conducted audible sound (ACAS).

Objective: Ultrasound was audible when delivered by bone conduction. Some profoundly deaf subjects as well as normal-hearing subjects can discriminate BCU whose amplitude is modulated by different speech sounds. These findings suggest the usefulness of developing a bone-conducted ultrasonic hearing aid (BCUHA). However, the characteristics of BCU are still poorly understood. The aim of the present study was to compare BCU and ACAS in terms of their associated speech perception tendency and to investigate the different perceptual characteristics of BCU and ACAS.

Subjects and methods: Speech discrimination tests using both BCU and ACAS were performed with normal-hearing subjects. BCU and ACAS were compared for intelligibility and hearing confusion.

Results: With BCU, the maximum percentage correct totaled about 75%. Our comparison of the hearing confusion with ACAS and BCU according to the individual syllabic nuclear group showed a clear difference in the incorrect rates. In addition, the stimulus nuclear groups were often perceived in other nuclear groups in BCU.

Conclusion: These activated areas may be related to the orbitofrontal cortex, corresponding to olfactory cortices. This study shows that multichannel near-infrared spectroscopy (NIRS) enables the evaluation of brain activity of normosmia subjects and dysosmia subjects by olfactory stimulation.

Objective: Objective olfactory testing is not common. NIRS has beenused before to study functional activations in various areas of the brain, but we wanted to investigate the difference in brain olfactory activity in normosmia subjects and dysosmia subjects using multi-channel NIRS (MNIRS).

Subjects and methods: This study was conducted on eight normosmia subjects and five dysosmia subjects. We employed a 22-channel near-infrared spectroscopy device with eight light incident fibers and seven light detector fibers, each with an inter-optode distance of 2.5 cm on the frontal head. Isovaleric acid was used as the odor stimulant. We measured the change in oxyhemoglobin concentrations [oxyHb], deoxyhemoglobin concentrations [deoxyHb], and total hemoglobin concentrations [totalHb] from pre-baseline values. Furthermore, we divided the frontal cortex into four areas (right upper, left upper, right lower, left lower) and measured the activity in each area. Then, the changes in [oxyHb], [deoxyHb], and [totalHb] of normosmia subjects and dysosmia subjects were compared in each area.

Results: In all normosmia subjects, isovaleric acid caused remarkable changes, especially in the lower areas of the frontal cortex. However, in all dysosmia subjects, isovaleric acid caused no changes.

Conclusion: The higher level of glucocorticoid receptor (GR) expression in cases of chronic sinusitis with bronchial asthma or allergic rhinitis suggests that glucocorticoids may exert a greater influence on eosinophils, thereby making them more effective in the treatment of polyps or chronic sinusitis.

Objectives: The GR immunoreactivity of eosinophils in nasal polyps was investigated to elucidate the mechanism by which glucocorticoids interact with eosinophils.

Materials and methods: Nasal polyp specimens were divided into 3 groups: 7 patients with chronic sinusitis alone (CS only group), 12 patients with chronic sinusitis complicated by perennial allergic rhinitis (CS/AR group), and 6 patients with chronic sinusitis complicated by bronchial asthma except for aspirin-induced asthma (CS/asthma group). Immunofluorescent staining with an anti-GR polyclonal antibody and anti-major basic protein (MBP) monoclonal antibody was used.

Results: The total number of MBP+ cells, GR+ cells, and MBP+/GR+ cells in the CS/asthma group was significantly higher than that in the other two groups. The total number of these cells in the CS/AR group was also higher than that in the CS only group The ratio of MBP+/GR+ cells to GR+ cells was highest in the CS/asthma group. The ratio of MBP+/GR+ cells to MBP+ cells in the CS only group was lower than those in the other two groups.

Conclusion: The results of the present study indicate the existence of natural immunity mechanisms via which viruses are eliminated from nasal and paranasal sinus mucosa.

Objectives: Acute sinusitis and acute aggravation of chronic sinusitis are often caused by bacteria, which are secondary to viral infection of the nose. Antiviral molecules are considered to be expressed and protect the host after viral infection. We investigated the expression of antiviral molecules after viral infection of the nose.

Materials and methods: We assessed the expression of antiviral molecules, defensin and interferon mRNA, by the real-time polymerase chain reaction (PCR) technique after stimulating cultured nasal polyp cells with polyinosine-polycytidylic acid (poly(I:C)), which is an analog of double-stranded (ds) RNA.

Results: The expression of beta-defensin mRNA significantly increased after the stimulation. On the other hand, expression of both interferon-alpha mRNA and interferon-beta mRNA was recognized, but only the expression of interferon-beta mRNA increased after the stimulation.

Conclusion: These results suggest that mast cells (MCs) play a role in promoting nasal polyp (NP) formation and progression with alpha-smooth muscle actin (alpha-SMA)-positive cells.

Objectives: We studied the quantification and the localization of MCs and myofibroblasts in NPs.

Patients and methods: We examined NPs from 12 patients with chronic rhinosinusitis undergoing endoscopic sinus surgery. MCs and myofibroblasts that expressed alpha-SMA were detected immunohistochemically. The numbers of labeled cells were quantified in NPs. These cells were evaluated in the tip, central, and pedicle areas. The number of MCs was compared between low (zone 1), moderate (zone 2), and high (zone 3) zones of alpha-SMA-positive cells.

Results: The number of MCs was significantly higher in pedicle areas than in tip areas of NPs. The distribution of alpha-SMA-positive cells tended to be more remarkable in pedicle areas than in tip and central areas of NPs. The number of MCs was significantly higher in zone 3 than in zone 1 of alpha-SMA-positive cells.

Conclusions: Prednisolone protects against inner ear damage, even when administered after ischemic injury in Mongolian gerbils.

Objective: The effect of prednisolone on ischemia-induced cochlear damage was investigated in Mongolian gerbils.

Materials and methods: The bilateral vertebral arteries were occluded for 15 min to transiently induce cochlear ischemia, followed by an intraperitoneal injection of prednisolone (1 mg/kg) or physiological saline (control). Sequential changes in hearing were evaluated by recording the auditory brainstem response (ABR) before and at 1, 4, and 7 days after treatment. In our histologic analysis, the numbers of dead and intact inner hair cells (IHCs) were counted in specimens stained with rhodamine-phalloidin.

Results: In control animals, transient ischemia increased the ABR threshold (24.2 +/- 8.6 dB) within 7 days of treatment, whereas prednisolone-treated animals exhibited a threshold of 14.2 +/- 9.2 dB. Furthermore, the percent IHC loss at the basal turn of the cochlea was 26.5 +/- 11.4% in control animals compared with 5.3 +/- 3.0% in the prednisolone-treated group.

A 58-year-old Japanese man suddenly suffered from vertigo. On physical examination, left-beating horizontal torsional spontaneous nystagmus was observed; the direction did not change with gaze. Other neurotological examinations revealed findings within normal limits except the left side sensorineural hearing loss of approximately 32 dB on average. Diffusion-weighted MRI revealed no infarction in the brain, but demonstrated an epidermoid cyst in the left cerebello-pontine cistern region. Using free digital imaging and communications in medicine (DICOM) image viewing and processing software, it was found that the epidermoid cyst clearly compressed the left anterior inferior cerebellar artery (AICA). Therefore, we speculated that insufficiency of the left AICA caused his audiovestibular symptoms. This new technique used in the present study was considered useful when the site responsible for vertigo is suspected in the cerebello-pontine angle, where anatomic relationships between the nerves and the vessels are complicated.

Conclusion: The significant up-regulation of matrix metalloproteinase (MMP)-9 mRNA, which is not modulated by tissue inhibitor of metalloproteinase (TIMP)-1, is an additional source of increased proteolytic activity in virus-infected upper airways that might contribute to the exacerbation of chronic rhinosinusitis with nasal polyps.

Objectives: Chronic rhinosinusitis is often exacerbated by viral infection. We hypothesized that a disruption of the mechanisms that regulate the activity of MMPs during viral infection is one possible mechanism responsible for the exacerbation. In the present study we attempted to achieve a better understanding of MMP expression in nasal epithelial cells after viral infection.

Materials and methods: Human nasal epithelial cells were isolated from nasal polyp specimens obtained during endoscopic endonasal surgery in chronic rhinosinusitis patients. We investigated the expression of MMP-2, MMP-9, and TIMP-1 mRNA in primary human nasal polyp epithelial cells after dsRNA stimulation.

Results: Among the genes whose expression was evaluated, only expression of MMP-9 mRNA increased significantly after dsRNA stimulation.