摘要:

Outer hair cells were isolated from apical turns of the guinea pig cochlea. The membrane potential differences of cells in extracellular medium with 5.8, 14.0, 28.9 or 67.5 mmol/l of potassium were ––72.0 ± 0.6 (mean ± SEM, n = 93), ––50.1 ± 2.1 (n = 4), ––37.7 ± 0.5 (n = 73) or ––20.0 ± 1.5 mV (n = 16), respectively. Membrane depolarization can explain two thirds of the K+-induced shortening of isola

ISSN:0301-1569    

DOI:10.1159/000276343

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effects of enkephalin and naloxone, applied iontophoretically, were tested on induced firing activity of the afferent dendrites on inner hair cells in the guinea pig. Enkephalin strongly depresses the depolarizing effect of N-methyl-D-aspartate (NMDA), quisqualate and kainate. Enkephalin exerted a stronger inhibitory effect on non-NMDA-induced fibre activity than on NMDA-induced activity. It was possible to block this inhibitory effect by applying the opiate antagonist naloxone, which suggests a specific enkephalin action. Our results appear to demonstrate that enkephalin acts as a neurotransmitter or a neuromodulator in the efferent neurones of inner hair cells which have synaptic contact to the afferents of the inner hair cells.

ISSN:0301-1569    

DOI:10.1159/000276344

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In guinea pigs, an acute acoustic trauma was created by 6 consecutive gunshots. The sound pressure at the ear drum was 156 ± 4 dB, the frequency maximum was between 4 and 6 kHz. Sixty hours after the noise trauma, the animals were decapitated, and the cochleae were prepared for microscopic analysis of the resulting trauma to the organ of Corti. During the process of fixation, the potassium-pyroantimonate precipitation reaction was performed to localize calcium-binding sites. The pattern of cell morphology and the distribution of calcium-binding sites was compared to that of normal control animals. Morphologic changes of the cells in the organ of Corti correlated with changes of the cellular calcium distribution, indicating the crucial role of calcium in cell damage and necrosis after acute noise trauma

ISSN:0301-1569    

DOI:10.1159/000276345

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The localization of carbonic anhydrase (CA) in mouse and guinea pig endolymphatic sac (ES) was determined by immunohistochemistry. In the distal and intermediate portions of the ES of both species, epithelial cells reacted with anti-CA antiserum. All epithelial cells in the distal portion stained for CA. In the intermediate portion, immunoreactivity was prominent in about half the epithelial cells, but less intense in the remaining epithelial cells. The proximal portion of the ES lacked immunoreactivity. CA may play a crucial role in ES electrolyte transport.

ISSN:0301-1569    

DOI:10.1159/000276346

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The stapedius muscle of the squirrel monkey (Saimiri sciureus) was studied electron microscopically with regard to neuromuscular junctions, muscle-tendon junctions and tendons. Two types of neuromuscular junctions were identified. The first type which was predominant in number showed well-developed primary and secondary synaptic clefts. They were almost the same with those of other mammalian skeletal muscles. The second type showed a flat-shaped junction with fewer secondary synaptic clefts. Muscle-tendon junctions were characterized by many interdigitations between the muscle fibers and tendon. The tendon was composed of collagen fibers, approximately 70-100 nm in diameter. Muscle spindles were not present, while nerve endings resembling the Golgi tendon organ were found adjacent to the tendon and the muscle-tendon junctions. These findings suggest that a feedback system may exist and regulate the fine contractile function of this muscle.

ISSN:0301-1569    

DOI:10.1159/000276347

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

We observed cases of hearing loss in which hearing deteriorated when steroid therapy was discontinued and improved upon re-administration. We identified these as cases of steroid-responsive sensorineural hearing loss (SNHL). The diagnostic criteria for determining steroid-responsive SNHL were stated, and 10 cases were examined. The 10 cases of steroid-responsive SNHL were divided into two groups: 3 cases associated with aortitis syndrome (systemic type) and 7 cases with no known systemic disease (localized type). Relatively satisfactory hearing was maintained in these cases by long-term oral administration of prednisolone (PSL). The combined use of Sairei-to made it possible to decrease the necessary maintenance dose of PSL. While the pathology of steroid-responsive SNHL is still unclear, it is suspected that immune complex disease or vasculitis may be involved.

ISSN:0301-1569    

DOI:10.1159/000276348

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A series of 95 consecutive patients who have had a polypectomy was investigated with regard to clinical history and the morphology of the polyps. The results were compared with a series of 203 patients with allergy, of whom 12 had been polypectomized. The study revealed that a high percentage of the 95 patients had subjective complaints, particularly nasal congestion, nasal discharge, sneezing, headache, snoring and a loss of smell. The latter was present in nearly 58 % of the patients, and persisted long after the operation in a third of the cases. More than 50 % of the 95 patients had had 3 or more polypectomies. Rather few patients suffered from allergy-like conditions. Eighty-two of the 95 polyps were of the ordinary, oedematous, eosinophilic type; 7 were neutrophilic, fibro-inflammatory; 5 showed pronounced hyperplasia of the seromucinous glands, and 1 was a so-called polyp with atypical stroma. Only 6 % of the 203 patients with allergy had had a polypectomy. Ten of the 12 polyps removed from the series of patients with allergy were of the ordinary type and 2 of the fibro-inflammatory type. A review of the literature is done concerning the association between nasal polyp and different diseases. The results of the present study support the concept that allergy is not the only cause for nasal polyps and that the accumulation of eosinophilic granulocytes observed in most polyps is often not related to allergy.

ISSN:0301-1569    

DOI:10.1159/000276349

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Nitrogen dioxide exposure-induced mucosal pathology of the guinea pig trachea was studied. Exposure to 3 or 9 ppm of nitrogen dioxide for 6 h a day, 6 times weekly for 2 weeks resulted in decreased ciliary activity as well as a dramatic eosinophil accumulation to the epithelium and submucosal layer. Especially exposure to 9 ppm of nitrogen dioxide induced epithelial injury through the activation of eosinophils accumulated in the tracheal mucosa. The epithelial damage induced by nitrogen dioxide could lead to hyperresponsiveness and prolonged allergic inflammation. Our study suggests that environmental nitrogen dioxide could contribute to the hyperresponsiveness and could most probably be involved in the development and chronicity of airway allergic disorders.

ISSN:0301-1569    

DOI:10.1159/000276350

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The results of fine-needle aspiration cytology (FNA) performed on 235 patients with head and neck growths were analyzed. The accuracy rate was 83 %. The FNA was nondiagnostic in 9 %, false negative in 7 % and false positive in 1 % of the cases. These results are similar to those in other centers. Due to false-negative diagnoses, FNA rarely allows the making of a major clinical decision. False-positive diagnoses oblige the clinician to perform several investigations to assess the diagnosis of nonmalignancy and to reassure the patient. Thus, in our opinion, FNA is helpful for the diagnosis of head and neck growths in some rare situations only.

ISSN:0301-1569    

DOI:10.1159/000276351

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A rare case of extramedullary plasmacytoma in the sino-nasal cavity is presented. During a prolonged clinical course, the tumor has recurred several times after irradiation, chemotherapy and surgery, and presented in the clavicular bone as well. Immunohistochemical staining of each tumor showed IgA k phenotype, and immunoelectrophoresis of the serum showed overproduction of IgA with k light chains. Although an elevation of serum IgA persists, the patient has remained well without evidence of overt multiple myeloma.

ISSN:0301-1569    

DOI:10.1159/000276352

出版商:S. Karger AG    

年代:1993

数据来源: Karger