Ionic changes in cochlear endolymph of the guinea pig induced by acoustic injury.

The effects of acoustic overstimulation on the endocochlear potential (EP) and on concentrations of ions (K+, Na+, Cl-, H+, HCO3-, and Ca2+) in endolymph were investigated using ion-selective microelectrodes. A slight but significant elevation of the EP and alkalinization of the endolymph were induced by acoustic overstimulation, whereas there was little change in the K+, Na+, Cl-, and HCO3- concentrations. The changes in H+ and HCO3- concentrations implied a depression of PCO2, suggesting an increase in blood flow to the cochlea.

Electrogustometry of the soft palate as a topographic diagnostic method for facial paralysis.

Electrogustometry (EGM) of the soft palate, innervated by the gustatory fibers running via the greater petrosal nerve, was performed in 10 cases with facial paralysis due to suprageniculate lesions to evaluate its clinical validity as a topographic diagnostic method. Lacrimal function was also examined for comparison. The results obtained from EGM showed a significantly increased threshold on the affected side in 90% of the cases.

Magnesium ion activity in the mammalian endolymph measured with ion-selective microelectrodes.

The free Mg++ concentration in endolymph was measured with Mg++-selective microelectrodes based on the neutral ligand ETH 1117. The property of Mg++ microelectrodes was obtained from calibration solutions, containing various Mg++ concentrations with the background electrolytes resembling endolymph. The range between 10 and 0.

Studies with electrocochleography and auditory brainstem response in Ramsay Hunt syndrome.

Eighteen cases of Ramsay Hunt syndrome were examined with electrocochleography and auditory brainstem response. Hearing was normal in 4 cases, while the other 14 exhibited sensorineural hearing loss ranging from mild to moderate in severity. Although the I-V interwave latency in all cases was within or slightly outside of the normal limits, the N1 latency was significantly prolonged in 8 cases proportionately to the degree of hearing loss at 4 and 8 kHz.

Treatment of secretory otitis media with kampo medicine.

Kampo medicine is a traditional Japanese herbal medicine that is known as Sairei-to and has been used to treat otitis media. This preparation was given orally for 4 weeks to 35 children with secretory otitis media (SOM). Four of 46 ears (8.

Early effects of acetazolamide on anionic activities of the guinea pig endolymph: evidence for active function of carbonic anhydrase in the cochlea.

The effect of acetazolamide (ACZ) on HCO3- and Cl- activities in inner ear fluid was investigated by ion-selective microelectrode methods. The endocochlear potential, at 81.6 +/- 1.

Sensorineural hearing loss associated with hypoparathyroidism.

The hearing loss of 21 patients with hypoparathyroidism was investigated by pure tone audiometry, short increment sensitivity index (SISI) test, Békésy audiometry, speech audiometry, and auditory brain stem response. Sensorineural hearing loss was found in 7 of 21 patients (13 of 42 ears) receiving no treatment for hypoparathyroidism or having chronic hypocalcemia. The high SISI score, presence of recruitment, and prolongation of the wave I (N1) latency suggested that the inner ear is responsible for hearing loss in these cases.

Pathophysiology and prognosis of sudden deafness with special reference to the N1 latency.

Electrocochleography (ECochG) was performed in 84 patients with sudden deafness which were classified into 3 groups according to the ECochG findings, i.e. the unchanged N1 latency, the prolonged N1 latency and the absence of N1 response.

The Ca2+ activity of cochlear endolymph of the guinea pig and the effect of inhibitors.

The Ca2+ concentrations in cochlear perilymph and endolymph of the guinea pig were measured with double-barreled Ca2+-selective microelectrodes and showed 1.76 +/- 0.74 X 10(-3) M and 2.

The effect of the cationic composition in perilymph upon the N1 latency of the guinea pig.

Although a suitable cationic composition in perilymph is known to be essential for the generation of N1, the effect of the cationic change upon the N1 latency has never been investigated in detail. The scala tympani was perfused with an artificial perilymph with a high K+, low Na+ or low Ca2+ content, with simultaneous measurement by an ion-selective microelectrode to observe its effect upon the N1 latency. An excess of K+, a depletion of Na+ and a depletion of Ca2+ in perilymph individually suppressed the N1 amplitude and elevated the N1 threshold.

Ultrastructural pathology of the middle ear mucosa in otitis media with effusion.

To elucidate the histopathological features of the middle ear mucosa in otitis media with effusion (OME), 33 specimens were obtained from OME patients (28 from children and 5 from adults) at the time of the ventilation tube insertion, and examined by light- and electron-microscopy. The mucosa from both pediatric and adult OME patients with glue effusion consisted mostly of non-ciliated cells containing numerous low electron-dense granules with or without a core, and many macroapocrine sections were observed on the apical surface of the cells. The mucosa with mucoid effusion showed various secretory activity, but macroapocrine secretions were rarely found.

Biological property of immune complex to prolong the duration of otitis media with effusion.

This study was designed to evaluate the biological properties of a light molecular weight immune complex, in comparison with that of a heavy molecular weight immune complex. Soluble immune complexes were obtained by mixing horseradish peroxidase (HRP) with guinea pig antiserum to HRP and were divided by gel filtration into several fractions according to their molecular weight (MW). After the chemotactic activity of each fraction was examined in vitro, the lightest and the heaviest MW immune complexes were injected into a guinea pig's left and right superior bulla, respectively.

Serial section reconstruction of the guinea pig outer hair cells as studied with a high-voltage electron microscope and a computer-graphic display.

The fine structural arrangement of the nerve endings on the guinea pig outer hair cells (OHCs) was studied by a serial sectioning technique by means of a high-voltage electron microscope and computer-graphic three-dimensional reconstruction. Sixty-nine series of consecutive sections were observed. Fifteen OHCs were located about 0.