摘要:

Hantavirus-induced acute viral infection of the inner ear of guinea pigs is reported. Guinea pigs were inoculated directly into the inner ear through the round window, or intraperitoneally with hantavirus (B-1 strain), and the cochlea was examined using an immunohistochemical technique for the localization of viral antigens. Virus-specific antigens were detected prominently in the stria vascularis and to a lesser degree in other inner ear structures of the infected guinea pigs. The morphological changes in the inner ear structures of these guinea pigs were observed. Virus was isolated from the blood of some infected guinea pigs. These data suggest that hantavirus can infect the inner ear of the guinea pig via viremia. The effect of immunosuppression by ciclosporin A or cyclophos-phamide is discussed.

ISSN:0301-1569    

DOI:10.1159/000276174

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

DC potential in the ampulla of pigeons was studied using a glass microelectrode. After the extirpation of the cochlear duct no change in the DC potential was found. A reduction of the negative DC potential due to anoxia (anoxia-sensitive negative potential, ASNP) was found in the ethacrynic acid (EA)-intoxicated ear, while this finding was minimal or absent in the ouabain-intoxicated ear. The perilymphatic perfusion with K+-substituted Ringer’s solution resulted in a rapid reduction of the negativity due to EA or ouabain. These findings indicate that the positive DC potential in the ampulla seems to be produced by itself and K+ diffusion potential is the main source of negative DC potential. ASNP may be the unique potential in the EA-intoxicated ear in warm-blooded animal

ISSN:0301-1569    

DOI:10.1159/000276175

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The expression of the five main groups of intermediate filaments and their subgroups, especially cytokeratins, was investigated in the guinea pig endolymphatic sac at the light microscopic level using immunohistochemistry. Immunostaining for cytokeratin (PKK1, PKK2, PKK3) was found in the epithelial cell layer of the sac. Vimentin was seen to stain epithelial cell layer as well as subepithelial tissue. These findings may indicate that the cytokeratins are closely related to the inner ear fluid transport. The coexpression of cytokeratin and vimentin seemed to indicate the dual function of absorption and secretion of the endolymphatic sac epithelial cell to regulate the inner ear fluid homeostasis.

ISSN:0301-1569    

DOI:10.1159/000276176

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The recovery time of temporary threshold shift after 1-kHz tone bursts delayed evoked otoacoustic emissions (DEOE) after the same stimulus were studied after auditory fatigue (AF) with a pure tone (0.75 kHz, 10 min, 95 dB HL) in 20 normal-hearing subjects aged 19–23 years. Close similarities were observed in the two experimental conditions. Since DEOE are transmitted to the outer ear via structures independent of the fibers of the afferent acoustic pathway and their synapses, it may be supposed that changes in the motile activity of the outer hair cells caused by AF could be partly responsible for their production and could constitute an active intracochlear mechanism taking part in this phenomenon. It may also be supposed that the effects of this active mechanism could be superimposed on those produced by a passive intracochlear mechanism consisting of the traveling wave induced in the basilar membrane by the perilymph owing to the movements of the stape

ISSN:0301-1569    

DOI:10.1159/000276177

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Ototoxicity affects the higher frequencies first and extends to the lower frequencies during continuation of the ototoxic treatment. Peritonitis due to continuous ambulatory peritoneal dialysis (CAPD) regularly demands ototoxic antibiotic treatment, e.g. with gentamicin and vancomycin. In this study ultra-high frequency audiometry (10–20 kHz), ‘normal’ audiometry (0.125–8 kHz) and registration of blood concentrations of the antibiotics were used to assess ototoxic hearing loss during treatment of CAPD patients with peri

ISSN:0301-1569    

DOI:10.1159/000276178

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The nystagmus response elicited by a velocity step of 90°/s was evaluated in a group of 500 consecutive patients By computer analysis and by measuring the duration (t, in s) of the first phase of the response. A 90% log normal range of 37–55 s (mean 45 s) was established for t directly from the electronystagmogram (ENG) in a group of 12 normal subjects. The computer-based response type ‘G–’, i.e. ‘Gesamtamplitude’ (cumulative eye displacement), G < 480°, yielded a detection rate of labyrinthine defects (LDs) of about 65 % with 35 % false positives and 15 % false negatives. A percentage of only about 25 of LDs was detected, with similar percentages of false detections, when using a criterion based on short t values. The lower yield was partly due to the fact that in some 35% of the cases t could not be measured; in the evaluable cases alone, the detection rate was 60% when using the G criterion and 50% when using the t criterion. It is recommended to measure G directly from the ENG, if t is too short or not available, whenever diminished vestibular responses

ISSN:0301-1569    

DOI:10.1159/000276179

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The surface tension of secretions from the pharyngeal orifice of the eustachian tube in eight rabbits was analyzed with a modified maximum-bubble pressure method. Measurements were made before, during, and after intravenous injections of isoprenaline (10 µg/kg). Surface tension was found to be 57.6 ± 0.9 (mean ± SEM) mN/m before injections, and was not significantly changed by isoprenaline. The surface tension in middle-ear secretions from children with secretory otitis media was also determined, the serous type of secretion measuring 62.0 ± 1.4 mN/m (n = 8), and the mucoid type 70.7 ± 2.6 mN/m (n = 9). In another ten humans, measurements of tears were performed, and the surface tension was found to be 59.9 ± 2.2 mN/m. This bubble technique promises to be useful for the evaluation of surface tension when the available sample volume is very

ISSN:0301-1569    

DOI:10.1159/000276180

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

In recent years, the rat has attracted increasing interest as an experimental animal in otological research. In the present study, the structure of the rat tympanic membrane (TM) is compared with that of a traditional experimental animal, the guinea pig, and with the human TM. The normal guinea pig TM consists mainly of a single layer of coarse fiber bundles, in contrast to the more solid layers of radial and circular fibers in man and rat. The investigation reveals similar architectural features in the rat and human TM, whereas the guinea pig TM differs structurally.

ISSN:0301-1569    

DOI:10.1159/000276181

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

A controlled randomized study was performed in 60 patients with 64 chronic, dry tympanic membrane (TM) perforations. The perforations were randomly allocated to either resection of the perforation rim and instillation of 1 % hyaluronan (Healon®; HYA) in the perforation gap once daily for 7 days (33 ears) or resection of the perforation margin and application of a sterile rice paper prosthesis (31 ears). The treatment effect was documented by TM photography and morphometric measurements of the perforation area. The hearing was assessed with pure-tone and high-frequency audiometry. After 2 months, 5 of the HYA-treated perforations (15 %) and 4 of the rice-paper-treated TMs (13%) were healed. After 1 year, 18 perforations (9 in each treatment group) were healed. In neither group were there any persistent adverse effects on hearing. It is noteworthy that 28% (18/64) of the chronic, long-standing TM perforations could be repaired by these technically simple and time-saving methods. Both procedures should be considered as easy first-choice alternatives to myringoplasty in selected cases

ISSN:0301-1569    

DOI:10.1159/000276182

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

A modified technique for palliative resections of malignant endobronchial tumors with the Nd:YAG laser is described. A special tracheoscope was used in conjunction with the instrument guide of a laser bronchoscope. The main advantage of this technique is easy and simultaneous access to both lungs for ventilation and surgical procedures. The method helps to separate surgical from anesthetic manipulations. The experience of over 70 operations using this technique provides evidence that the use of a tracheoscope is a safe and efficient method of endoscopic resections of larger intrabronchial tumors.

ISSN:0301-1569    

DOI:10.1159/000276183

出版商:S. Karger AG    

年代:1991

数据来源: Karger