Objective assessment of subjective tinnitus through contralateral suppression of otoacoustic emissions by white noise; suggested cut-off points.

OBJECTIVE: Normative otoacoustic emission (OAE) suppression values are currently lacking and the role of cochlear efferent innervation in tinnitus is controversial. The aim of this study was to investigate the association between tinnitus and medial olivocochlear bundle (MOCB) malfunction. Potential suppression amplitude cut-off criteria that could differentiate participants with tinnitus from those without were sought. DESIGN: Mean suppression amplitudes of transient evoked OAEs and distortion product OAEs by contralateral white noise (50 dBSL) were recorded. Six mean suppression amplitudes criteria were validated as possible cut-off points. STUDY SAMPLE: The population consisted of normal hearing (n = 78) or presbycusic adults (n = 19) with tinnitus or without (n = 28 and 13, respectively) chronic tinnitus (in total, n = 138 78 females/60males, aged 49 ± 14 years). RESULTS: Participants with mean suppression values lower than 0.5-1 dBSPL seem to present a high probability to report tinnitus (specificity 88-97%). On the other hand, participants with mean suppression values larger than 2-2.5dBSPL seem to present a high probability of the absence of tinnitus (sensitivity 87-99%). Correlations were stronger among participants with bilateral presence or absence of tinnitus. CONCLUSIONS: This study seem to confirm an association between tinnitus and low suppression amplitudes (<1 dBSPL), which might evolve into an objective examination tool, supplementary to conventional audiological testing.

In vitro and in vivo inhibition of Helicobacter pylori by Lactobacillus casei strain Shirota.

We studied the potential inhibitory effect of Lactobacillus casei strain Shirota (from the fermented milk product Yakult [Yakult Ltd., Tokyo, Japan]) on Helicobacter pylori by using (i) in vitro inhibition assays with H. pylori SS1 (Sydney strain 1) and nine H. pylori clinical isolates and (ii) the in vivo H. pylori SS1 mouse model of infection over a period of 9 months. In vitro activity against H. pylori SS1 and all of the clinical isolates was observed in the presence of viable L. casei strain Shirota cells but not in the cell-free culture supernatant, although there was profound inhibition of urease activity. In vivo experiments were performed by oral administration of L. casei strain Shirota in the water supply over a period of 9 months to 6-week-old C57BL/6 mice previously infected with H. pylori SS1 (study group; n = 25). Appropriate control groups of H. pylori-infected but untreated animals (n = 25) and uninfected animals given L. casei strain Shirota (n = 25) also were included in the study. H. pylori colonization and development of gastritis were assessed at 1, 2, 3, 6, and 9 months postinfection. A significant reduction in the levels of H. pylori colonization was observed in the antrum and body mucosa in vivo in the lactobacillus-treated study group, as assessed by viable cultures, compared to the levels in the H. pylori-infected control group. This reduction was accompanied by a significant decline in the associated chronic and active gastric mucosal inflammation observed at each time point throughout the observation period. A trend toward a decrease in the anti-H. pylori immunoglobulin G response was measured in the serum of the animals treated with lactobacillus, although this decrease was not significant.

How significant is sensorineural hearing loss in primary Sjögren's syndrome? An individually matched case-control study.

OBJECTIVE: We evaluated whether sensorineural loss and vestibular abnormalities are common in patients with primary Sjögren's syndrome (pSS) and whether such abnormalities are clinically significant. METHODS: In an individually matched case-control design, 48 patients with pSS underwent complete audiovestibular evaluation along with 48 age and sex matched individuals without otologic problems. Differences of > 20 dB between patient and control ears at any frequency tested were considered to be significant. RESULTS: Significant differences in hearing loss were seen at 4,000 Hz (6 vs 0 ears; p = 0.03) and at 8,000 Hz (9 vs 0 ears; p = 0.003). Small differences in hearing acuity were also observed in the lower frequencies, but the absolute mean difference was < 3 dB. A decrease of at least 60 dB in hearing acuity at any frequency up to 4,000 Hz was seen only in 3 elderly pSS patients. Abnormal brainstem auditory evoked responses were recorded in 7 patients and 5 controls, but no patient had retrocochlear lesions identified on magnetic resonance imaging. Four patients in each group had abnormalities on electronystagmography. CONCLUSION: pSS is associated with sensorineural hearing loss affecting preferentially the high frequencies, but clinically significant defects are not common. There is no evidence of retrocochlear disease or increased vestibular involvement in pSS.