Binocular and monocular measurements of subjective visual vertical in vestibular loss.

The objective of this study was to investigate the possibility to omit the time-consuming monocular vision measurement in the subjective visual vertical (SVV) test by demonstrating that there is no difference in the results between binocular and monocular measurements. Thirty-one patients with unilateral vestibular schwannoma and 20 normal subjects as controls were involved. Both binocular and monocular measurements of SVV were performed. The main outcome of this study was the difference in the results of SVV between binocular and monocular measurements. There were no significant differences in the tilts of the SVV between binocular and monocular measurements in vestibular schwannoma patients as well as in the controls. Abnormal tilts of SVV may be evaluated precisely only by binocular vision instead of monocular vision.

Expression of the osmotically responsive cationic channel TRPV4 in the endolymphatic sac.

The immunohistochemical expression pattern and the physiological role of transient receptor potential vanilloid (TRPV) 4 in the endolymphatic sac were investigated. TRPV4 was expressed predominantly in the apical membrane of mitochondria-rich cells, and cell volume regulation by TRPV4 was observed in a tissue culture of the rat endolymphatic sac. TRPV4 was also present in the endolymphatic sacs of patients with vestibular schwannoma and with Ménière's disease. TRPV4 is assumed to play a role as an osmoreceptor in cell and fluid volume regulation in the human endolymphatic sac.

Use of potassium tellurite for rapid-drug susceptibility testing of Mycobacterium avium complex.

BACKGROUND: Mycobacterium avium complex (MAC) is a major cause of infection in immunocompromised patients. MAC possesses an enzyme that reduces potassium tellurite in less than 3 days and results in formation of a black precipitate. The objective of this study was to determine whether reduction of potassium tellurite by mycobacteria can be used as a means of testing the susceptibility of MAC to clarithromycin. METHODS: Minimum inhibitory concentrations (MICs) for 104 clinical isolates of MAC were determined by the tellurite method and compared with those tested by a recommended microdilution method. Microdilution breakpoints were used for interpretation of susceptibility. MIC of less than 8 microg/mL was considered as susceptible, and MIC of greater than or equal to 8 microg/mL was resistant. RESULTS: There was agreement within a 2-fold dilution between MICs for 89% of isolates. Of the 53 isolates that had discrepant MICs by the two methods, 70% had higher MICs by the tellurite method. When the MICs were classified into interpretive categories, there was 100% agreement by the two methods. The MIC tested by the tellurite method was available within 5 days. CONCLUSIONS: These data suggest that use of potassium tellurite is a more rapid, reliable, and inexpensive method of testing the susceptibility of MAC to clarithromycin.