[THE function and morphology study of eustachian tube based on sonotubometry and multi-slice spiral CT in normal subjects].

Objective: In order to assess ET more comprehensively, sonotubometry (STM)combined with CT images were applied to investigate the opening features of eustachian tube (ET) in normal subjects. STM was also used as a monitor training ET opening maneuver and optimizing CT scan parameters. Methods: Following ET opening training monitored by STM, STM data of ET opening duration and maximum sound pressure from 13 healthy volunteers (10 males and 3 females, 22 to 26 years old) were acquired using maneuvers of swallowing and Valsalva in standing and supine positions. Two trials of CT scan, setting A (slice thickness 6.0 mm, manually simulated to 0.6 mm, reconstruction thickness 0.6 mm) for normal and Valsalva scans and setting B(slice thickness 0.4 mm,reconstruction thickness 0.4 mm)for Valsalva scan, were conducted in each subject. The bone area and cartilage area of ET were measured respectively in reconstructed CT images. Statistical software SPSS 19.0 was employed in data analysis. Results: The duration of ET opening and maximum sound pressure by Valsalva were longer and stronger than those by swallowing in both positions. For Valsalva maneuver, standing position resulted in longer ET opening duration compared to supine position (P<0.05). Under setting A, ET cartilage area was measured larger by Valsalva scan than by normal scan (P<0.05). By Valsalva scan, setting A captured larger ET cartilage area compared to setting B (P<0.05). CT setting B resulted in longer scan time in comparison to setting A (P<0.05). Conclusions: Techniques of STM in supine position plus CT scan under setting A can be combined by Valsalva passive ET opening. Not only the invisible ET lumen through routine CT scan can be illustrated, but also relevant ET open-close process is shown, therefore, this study provides the technique for ET research of function and structure.

Elevated interleukin-4 and interleukin-6 in rats sensitized with toluene diisocyanate.

In order to investigate the cytokine profile in toluene diisocyanate (TDI)-induced occupational asthma, we conducted a quantification of cytokine production in a murine model of respiratory hyperreactivity to TDI. Wistar rats were sensitized with intranasal application of 10% TDI and provoked with 5% TDI to induce airway hypersensitivity. The blood leucocytes were counted, and bronchoalveolar lavage (BAL) was performed and the cellular responses in BAL fluid were analysed. Lung histological examination was performed to investigate the inflammatory status in the airway. The production of IL-2, IL-4, IL-6 and IFN-gamma in serum, BAL fluid and spleen cell were determined with ELISA kits. The cellular results demonstrated that neutrophils and eosinophils in blood were significantly increased and the total cells and each different cell, in particular eosinophils in BAL fluid were markedly increased in TDI sensitized rats. Histological analysis showed that a respiratory inflammation represented by prominent infiltration of eosinophils in central and peripheral airways was present in TDI-sensitized rats. The cytokine assays revealed that in TDI-sensitized rats, IL-4 was predominately secreted in serum, and IL-4 and IL-6 rather than IL-2 and IFN-gamma were predominately secreted in BAL fluid and in spleen cell. These findings suggested that IL-4 and IL-6 are preferentially produced and may have an important role in occupational asthma induced by TDI.

An acoustically evoked short latency negative response in profound hearing loss patients.

In our auditory brainstem response (ABR) tests, a peculiar V-shaped negative wave at around 3 4 ms latency was observed. At present, this acoustically evoked short latency negative response (ASNR) is poorly understood. In order to study its appearance and origin, the ABR data of 3104 tests during 1980-98 were reviewed. The ASNR was found only in profound hearing loss ears under intense stimuli (80-120 dB nHL). Out of the total 653 profound hearing loss patients (981 ears), the click-evoked ASNRs were present in 80 patients (12.3%), 117 ears (11.9%). The age range was from 8 months to 70 years. Demographic outcome revealed significant higher appearance rates in young subjects especially in the 20-30 years group. The ASNR was excluded from an artifact by its reproducibility over time, equipment and institutes. Moreover, it became absent after external auditory canal occlusion, which simply blocked the air conduction without any influence upon scalp potentials or equipment. It had neural response characteristics that the latency and amplitude shortened and increased respectively in response to the increase of stimulus intensity. Because the peculiar V-shaped waveform obviously differs from ABR, the ASNR was not interpreted as a potential generated from the conventional auditory pathway. On the other hand, the ASNR individuals were of good vestibular function in sharp contrast with their poor hearing. This suggests the probable relation between the ASNR and the vestibular system. The saccule and vestibular nucleus are hypothesized to be the sense organ and the origin of the response respectively.