ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

A case of cavernous hemangioma of the tympanic membrane is presented, with pertinent literature review and suggestions for surgical management of these lesions.

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The end-organs of the human vestibular system were studied with transmission electron microscopic and freeze-fracturing techniques. The general morphology of the sensory epithelia was comparable to that of animals. The hair cells consisted of flask-shaped type I hair cells with the surrounding nerve calyx and rod-shaped type II hair cells contacted by several small bouton-shaped nerve endings. The hair cells were coupled to neighboring supporting cells by tight junctions at the lateroapical aspect. These were regular in appearance and of the moderately tight type. This type of tight junction has been found elsewhere in the inner ear and is believed to be competent to maintain its unique ion composition. The lateral surfaces of the supporting cells were coupled by gap junctions. The afferent nerve terminal of the type I hair cell, the so-called calyx, totally encompassed the hair cell. It could not be concluded on the basis of the present material whether the type I hair cell-calyx complex mediates electrical or chemical synaptic contact. The synapses of afferent nerves on type II hair cells, however, displayed typical signs of being chemically mediated. Synaptic bodies, similar to those seen in animals, were associated with the presynaptic membrane inside the hair cell. Membrane specializations comparable to those of animals were also seen in these synapses. Efferent nerve endings and synapses were not readily identified and were thus not discussed in this study.

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The fenestrated blood vessels surrounding the endolymphatic sac in guinea pigs were investigated with the help of freeze-fracturing. The technique exposes the structure and distribution of vascular pores as well as interendothelial bridges or tight junctions between vascular endothelial cells. It is possible to get a three-dimensional comprehension of the vascular structure which can be compared with that of conventional transmission electron microscopy (TEM). Discontinuity in the junctional elements as seen in some endothelial layers and the high number of fenestrations organized in geometric patterns, as well as the abundant, randomly distributed micropinocytotic vesicles seem to bear out the theory that the endolymphatic sac is one of the most metabolically active parts of the inner ear and may be involved in the turnover of endolymph.

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Brain stem auditory evoked potentials were recorded from 26 normal subjects who listened to 100 ms clicks at 10, 20, 50, and 100 repetitions per second at varying intensities. A 0.5±0.3 ms shift of the V wave latency was observed between 10 clicks per second and 100 clicks per second; a lesser difference was found when the repetition rate was shifted between 10 to 50, 20 to 50, or 20 to 100 clicks per second. No significant differences were observed when the repetition rate moved from 10 to 20 or between 50 and 100 clicks per second.Whatever latency shifts were observed appeared to be independent of the stimulus intensity.Waveform morphology seemed to be the same between 10 and 20 clicks per second, with only minor changes observed at the 50 clicks per second rate. At 100 clicks per second a decrease or a complete disappearance of some components or both was seen.These changes are accounted for by peripheral phenomena for the most part, and a number of clinical applications are suggested based on these observations.

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The measurement of brain stem evoked potentials has proven clinically useful in determining the presence of multiple sclerosis plaques along the auditory areas of the brain stem. Abnormalities in brain stem evoked responses (BSER) have been identified in patients who manifest normal hearing acuity when evaluated via conventional audiometric techniques. The following case presentation illustrates this confounding clinical finding. The patient was a 20-year-old female who had been previously diagnosed as having multiple sclerosis. Within one month after being evaluated by BSER testing, she was struck and killed by lightning. Although she had a detailed history of normal hearing acuity (documented over the last six years), BSER test results yielded significantly abnormal 'neural conduction times when the left ear was ipsilaterally stimulated. A histopathologic examination of the patient's brain stem verified involvement of the auditory tracts. Thus physical corroboration of the abnormal BSER results was obtained in the presence of normal hearing acuity.

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1983

数据来源: OVID