摘要:

Alterations of the auditory system during ageing and after noise damage have been studied earlier in two genotypes of mice, CBA/Ca and C57BL/6J, the former of which shows a late-onset hearing loss and the latter a high susceptibility to ageing and acoustic trauma early in life. The two strains display similarities to the different types of human age-related hearing loss. In the present study, the different patterns of hair cell degeneration were visualized by phal-loidin-labelled actin in the two strains of mice with increasing age. At 1 month of age there were no major differences in the actin distribution between the two genotypes. With increasing age, CBA mice retained a regular pattern of actin content in the cuticular plate but some hair cells were missing. In contrast, the C57BL mice showed a severely distorted architecture of the cutis plate (CP) with less actin labelling, missing hair cells and scar formation. The instability of actin in the hair cells of C57BL mice might result in their high susceptibility to ageing and noise damage.

ISSN:0301-1569    

DOI:10.1159/000276695

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The effects of glycerol were investigated in guinea pigs in which the endolymphatic sac (ES) and duct (ED) had been obliterated unilaterally. Twenty-four hours after obliteration of the right ES and ED, glycerol was injected intraperitoneally. One to two hours after administration of glycerol, collapse or folding of Reissner’s membrane was observed in the operated cochlea. No remarkable change was found in the nonoperated ear. The lumen of the ES of the nonoper-ated ear collapsed with intraluminal stainable substance within 1 h. The volume of the stainable substance increased with time and could still be seen 4 h after the injection of glycerol. Twenty-four hours after the injection of glycerol, the configuration of the ES was normal again. In addition, the animals showed marked unilateral (operated side) vestibular dysfunction after injection of glycerol. These findings suggest that the ES also has a secretory capacity and plays an important role in inner ear fluid volume and pressure regulatio

ISSN:0301-1569    

DOI:10.1159/000276696

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Previous experiments demonstrated an organ-specific migration of sensitized lymphocytes to the inner ear and enabled us to establish an animal model for an autoimmunological labyrinthitis in the guinea pig. For a nonrandom emigration from capillaries into tissues of their immunological destination, memory lymphocytes need homing receptors on their cell surface to interact with specialized postcapillary venules, the so-called high endothelial venules. These molecules were already demonstrated in organs of the mucosa-associated lymphatic system (MALT). This study was performed to demonstrate these adhesion molecules on endothelial cells and lymphocytes of the inner ear by using two monoclonal antibodies: MECA-325 and MEL-14. Special interest was directed to the posterior spiral modiolar vein as a known port of entry for lymphocytes during an immune response. Emphasis was placed on the development of new or additional binding sites for lymphocytes on the above-mentioned structures using immunohistochemistry during an immune response of the inner ear. The results suggest a constant recirculation of memory lymphocytes through the endolymphatic sac as known for other organs of the MALT. The acquisition of high endothelial venules in the cochlea during an immune response could serve for the cellular requirements of a sympathetic cochleo-labyrinthitis with the spiral modiolar vein as port of entry for lymphocytes. Furthermore, this study supports the hypothesis of the endolymphatic sac as central immunological control organ of the inner ear and as the primary place for antigen processing.

ISSN:0301-1569    

DOI:10.1159/000276697

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The effect of substance P on surgically removed human Scarpa’s ganglion cells was investigated by intracellular recordings and bath application under in vitro conditions. The neuropeptide produced a slow depolarization of the membrane potential which was accompanied by an increase in membrane resistance. Furthermore, an enhanced firing in response to depolarization occurred. The results strongly support a modulatory action of the neuroactive peptide substance P on human Scarpa’s ganglion ce

ISSN:0301-1569    

DOI:10.1159/000276698

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

We report here a newly developed video system which combines a three-dimensional and high-definition television system (Hi-Vision) for microsurgery of the ear. This system provides a high-quality three-dimensional documentation of the otomicrosurgical procedure, making it convenient and beneficial for easy understanding of the otherwise difficult to visualize areas in the middle and inner ear, especially in the context of postgraduate training.

ISSN:0301-1569    

DOI:10.1159/000276699

出版商:S. Karger AG    

年代:1995

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000276700

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Evidence is growing that the carbohydrate portion of glycoconjugates is not merely an inert structural addition to the protein or lipid background, but is involved in normal and altered physiological processes. Conjugation of the potentially bioactive carbohydrate ligand to an inert labeled carrier generates the tools to histochemically monitor the presence of sugar receptors like lectins in tissue sections. In head and neck squamous cell carcinoma endogenous lectins have been systematically characterized by a selected panel of conjugates of such synthetic probes. In this investigation we provide evidence that the anti-neoplastic agents carboplatin and 5-fiuorouracil influence the expression of carbohydrate-binding receptors. In cases with a statistically significant alteration, an increasing loss of binding capacity from treatment cycle to cycle was observed in cytoplasmic areas. This means that the extent of binding of β-N-acetyl-galactosamine, cellobiose, galactose, and sialic acid was affected. The pattern of diminished binding capacity in nuclear structures encompassed β-N-acetyl-galactosamine, β-N-acetyl-glucosamine, sialic acid as carbohydrate part of the neoglycoprotein. Thus, exposure to certain chemotherapeutic agents clearly influences the capacity of tumor cells to mediate protein-carbohydrate interactions. Concomitant with the elucidation of the functions of such an interplay the significance of this down-regulation will be appare

ISSN:0301-1569    

DOI:10.1159/000276701

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The beneficial effects of basic fibroblast growth factor (bFGF or FGF-2) in healing of tympanic membrane (TM) perforations have been demonstrated in animal models, and this study was conducted to investigate the effect of neutralizing anti-FGF-2 antibodies on acute tympanic membrane perforation healing. Anti-FGF-2 rabbit polyclonal antibodies were applied to traumatic TM perforations in guinea-pigs on days 0, 1, 2 and 3, whilst the opposite ear was treated with normal rabbit serum. On day 4, the perforation area was assessed, and the histological structure of the scar was studied. The average opening was larger in the neutralizing anti-bFGF-treated group, but the difference was not statistically significant. Histological analysis showed that scars treated with neutralizing anti-bFGF contained significantly less epithelial cells and less mononuclear cells. They also contained less fibroblasts and less vessels, but this difference was not significant. These data suggest that FGF-2 is one of the factors involved in the control of epithelial cells proliferation and mononuclear cell invasion in the initial phase of TM perforation healing. Neutralizing anti-bFGF antibodies could be of use in reducing the inflammation during the healing of TM perforations or to create animal models of chronic tympanic membrane perforations.

ISSN:0301-1569    

DOI:10.1159/000276702

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Nonorganic hearing loss or pseudohypacusis is a condition in which there is an apparent hearing loss without any evidence of an organic cause. In a 2-year period, 43 children were seen in our department with this diagnosis. Thirty-three of them were female and 10 were male. Their hearing loss varied from 30 dB HL to 100 dB HL. The diagnosis made on clinical impression was confirmed using the ascending and the descending mode pure tone audiometry, tympanometry, stapedial reflexes and speech audiometry. Explanation, encouragement and reassurance were the only treatment required in these patients. All the 43 patients showed normal pure tone thresholds within a period of 1 year.

ISSN:0301-1569    

DOI:10.1159/000276703

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Therapy with antituberculosis drugs is not indicated in patients with isolated cervical lymph node infection due to mycobacteria other than tuberculosis (MOTT); resectional surgery is the treatment of choice in these cases. The reason for this study was a striking increase in the incidence of this disease in children referred to the University Hospital in Aachen. In the period from 1987 to 1990, we saw only 1 case of nontuberculous mycobacterial cervical lymphadenitis among 77 cultured specimens; in contrast to this, out of 85 specimens examined between 1991 and March 1993 were positive, with an increasing tendency. The patients were treated surgically by adequate conservative neck dissection. The outcome was excellent in all cases.

ISSN:0301-1569    

DOI:10.1159/000276704

出版商:S. Karger AG    

年代:1995

数据来源: Karger