摘要:

A probable relation between prostaglandin formation and the pathophysiology of hearing loss led to the application of the potent vasodilator prostacyclin in the treatment of inner ear disorders. Two drugs may be administered to humans: (1) unstable natural prostacyclin (epoprostenol) with a strong biological potency but with a high first-pass effect, or (2) a prostacyclin analogue (taprostene) with less biological activity, but a longer biological half-life and intravenous application. Therefore, the purpose of this study was to investigate potential differences of both drugs in their effect on the inner ear. The therapeutic potency of both drugs was evaluated in a recently developed animal model consisting in the recovery of hearing after a temporary threshold shift obtained by two noise exposures at 100 dB. In addition, the ultrastructure of the stria vascularis was examined by electron microscopy after the application of the drugs. After administering epoprostenol (12 ng/kg body weight/min) and taprostene (25 ng/kg body weight/min) histomorphological alterations in the stria vascularis did not differ from the controls. In the repetitive low-level noise model, neither drug showed a significant difference in its effect on the recovery of the hearing threshold. The results indicate that in the guinea pig epoprostenol has the same effect on the hearing threshold as the stable analogue taprostene, as shown by auditory brain stem response.

ISSN:0301-1569    

DOI:10.1159/000276681

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The detection of platinum in cochlear outer hair cells (OHCs) and renal proximal tubule cells was attempted by X-ray microanalysis and ion microscopy. Platinum was not detected by X-ray microanalysis in the lysosomes of OHCs or proximal tubule cells after 10 days treatment with 1.5 mg/kg of cisplatin. In the guinea pigs treated with 1.5 mg/kg of cisplatin for 14 days, platinum was detected by a wave-length-dispersive microanalyzer in only the lysosomes of kidney fixed by freezing. Ion microscopy failed to detect platinum. Improvement of fixation methods, longer administration of cisplatin and the use of more sensitive tools will be needed to detect the platinum inside the OHCs.

ISSN:0301-1569    

DOI:10.1159/000276682

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Functional and morphological alterations were compared in guinea pig cochleae treated acutely (7.5 mg/kg × 2) and chronically (1.5 mg/kg × 10) with cisplatin. Drastic and rapid hearing impairments using compound action potential were observed only after the second injection during acute treatment. During chronic treatment, threshold changes were observed abruptly after 8 or 9 days of treatment. Morphological changes of outer hair cells were stronger in the acute treatment than the chronic one, and they appeared to concur with the functional data. Partial damage in the stria vascularis was observed only after acute treatment. From these results, it was suspected that acute and chronic ototoxic mechanisms differed according to the pharmacokinetics of cisplatin in the inner ear fluid and tissue

ISSN:0301-1569    

DOI:10.1159/000276683

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The postcaloric nystagmus (PCN) by positional change from the supine position to the upright position and other neurootological findings were studied. Twnety-one patients with a clinical diagnosis of spinocerebellar degeneration or Arnold-Chiari malformation were studied. There was a significant negative correlation between maximum slow phase eye velocity in postcaloric nystagmus by positional change (V2) and maximum slow phase eye velocity in optokinetic nystagmus pattern test (r = ––0.47; n = 21). Moreover, patients with vertical gaze nystagmus (VN) had significantly larger V2 than patients without VN. However, there was no significant difference for V2 between patients with and without rebound nystagmus. Through these studies, the authors discussed probable mechanisms and responsible lesions for the exaggerated PCN by positional cha

ISSN:0301-1569    

DOI:10.1159/000276684

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Analysis of gait in patients with acute unilateral peripheral vestibular disorders was performed using foot switches and electromyography, with the aid of a telemetry system. Among the eight parameters set for the analysis, the occurrence rate of abnormality in the coefficient of variation (CV) was the highest (78%) for the time from heel strike to forefoot strike, followed by that of the location of maximum monophasic contraction of the gastrocnemius during stance, swing and stance. No significant laterality concerning the abnormally increased CV value in those parameters was found except for swing of the foot contralateral to the lesion side. The CV value of each parameter was significantly increased by removing visual cues, suggesting the importance of visual input for steady locomotion. No significant change in CV values of double support was obtained during the acute stage of vestibular neuronitis, indicating that weight transfer from one leg to the other could be smooth even though some difficulty was expected. Abnormal parameters at an acute stage returned to normal limits at recovery stage. The physiological background of the obtained results is discussed.

ISSN:0301-1569    

DOI:10.1159/000276685

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The prognosis and the recovery process of facial nerve paralysis were reviewed in 74 patients who, despite preservation of nerve continuity, showed no facial movement after acoustic neuroma resection. In 50 or 67.6% of patients, facial movement recovered sufficiently so as not to require any reanimation procedures. However, no apparent sign of remission was observed for 7–49 months in the other 24 patients (32.4%), and hypoglossal-facial nerve anastomosis was performed in 20 of these patients. When remission was seen, the first sign of muscle movement appeared most frequently after 3–4 months but, in a small number of patients, it was also seen within 1.5 months or after 5–10 months. Based upon these results, the timing of reanimation procedures for facial nerve paralysis following acoustic neuroma resection is disc

ISSN:0301-1569    

DOI:10.1159/000276686

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The correlation between nasal mucosal swelling and estimated stuffiness was evaluated in 13 healthy volunteers who entered the trial. The nasal mucosa was challenged with increasing concentrations of histamine solutions. The amount of mucosal swelling was recorded using rhinostereometry, and the stuffiness was estimated by the subjects on a visual analogue scale. Then the subjects were randomly chosen to receive either oxy- or xylometazoline nasal spray for 30 days. After 10 days on the drug, the histamine sensitivity was enhanced, and after another 20 days, it had increased further, reflecting the development of rhinitis medicamentosa. Before the subjects started the nasal spray and after 10 days on the drug, a correlation between stuffiness and swelling was seen in the individual subject only when the degree of stuffiness almost obliterated the nasal opening. At the end of the month, no correlation was present. In all histamine provocations throughout the month, a very high correlation was noted between mean mucosal swelling and mean stuffiness. It is concluded that the symptom scores for nasal obstruction are useful for determining nasal mucosal swelling in groups. However, in the individual subjects one can estimate the mucosal swelling only when the amount of swelling almost obliterates the nasal opening. This cannot be done when the mucosa is hyperreactive.

ISSN:0301-1569    

DOI:10.1159/000276687

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Auditory brainstem responses (ABRs) were recorded in 2 patients with hearing loss caused by leptomeningeal metastatic spread. These recordings showed similar characteristic findings. The absolute latencies of wave V and interwave latencies I-V were exceedingly increased. Definite effects on the wave morphology and latency of wave V were observed with the use of high repetition rates. It is surmised that the hearing loss caused by leptomeningeal metastatic spread is mainly an effect on the auditory nerve and/or the cochlear nucleus. ABR examination is of clinical value in detecting functional abnormalities resulting from leptomeningeal metastatic spread.

ISSN:0301-1569    

DOI:10.1159/000276688

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

We report a case of nasopharyngeal carcinoma (NPC) accompanied by hyponatremia and polyuria which was induced by tumor invasion into the pituitary gland. Magnetic resonance imaging showed the pituitary gland pushed upward by NPC. Hypopituitarism due to an intracranial tumor and the extracellular volume excess due to chemotherapy caused hyponatremia and polyuria. As the intracranial tumor was diminished by chemotherapy and irradiation, pituitary hormones were normalized. In patients with T4 NPC, pituitary-adreno-cortical function should be endocrinologically evaluated before treatment.

ISSN:0301-1569    

DOI:10.1159/000276689

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000276690

出版商:S. Karger AG    

年代:1994

数据来源: Karger