ISSN:0301-1569    

DOI:10.1159/000276293

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Modern immunohistochemical methods allow a functional characterization of the human endolymphatic sac (ES) and its associated cell populations. The currently available immunohistochemical data on the extraosseous part of the human ES support the assumption that the epithelium is metabolically active and capable of both secretion and absorption. The reactivity of some epithelial cells with antibodies against neuroendocrine antigens implies a paracrine activity of the human ES. Further results provide evidence for a possible role of the human ES in inner ear immune defense and indicate a putative functional relationship of the human ES to the common mucosa-associated immune system.

ISSN:0301-1569    

DOI:10.1159/000276294

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The cytodifferentiation of the human endolymphatic sac was studied in the period between gestational weeks 8 and 20. This period is of particular interest since it covers the major part of the morphological and functional maturation of the human inner ear. The studied time, i.e. 8–20 weeks of gestation, may be divided into three periods. Before week 10, between weeks 11 and 15 and weeks 15–20. While the endolymphatic sac appears as a simple slit-like appendage in the first period, until week 10 with cells of uniform size and shape, a beginning cytodifferentiation occurs in the second period between weeks 10 and 15. Thus the cells attain a more mature shape with different stainability, i.e. light- and dark-staining cells, as well as open lateral intercellular spaces indicating some functional maturity. In the third period, after week 15, the endolymphatic sac more or less seems mature with a rugose appearance in its proximal portion and a more even, slit-like appearance in the distal portion. The cells are differentiated with morphological signs of functional maturation. It may be concluded that the development of the endolymphatic sac roughly follows that of the cochlea which is regarded to be functionally mature in the beginning of the second half of pregna

ISSN:0301-1569    

DOI:10.1159/000276295

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Lectin-conjugated horseradish peroxidase (WGA-HRP) was used as a retrograde axonal tracer to determine endolymphatic sac (ES) innervation and the nature of such a nervous supply. WGA-HRP placed into the ES of the guinea pig resulted in labelling of neurons in the ipsilateral sympathetic superior cervical ganglion and the sensory trigeminal ganglion. The number of labelled neurons in the cervical superior ganglion varied according to the survival time with peak labelling occurring after 48 h. Sparse labelling of the sensory trigeminal ganglion was also present after 48 h. The results indicate that sympathetic neurons from the superior cervical ganglion and to a certain extent trigeminal somatosensory neurons innervate the ES or perisaccular tissue. If these findings reflect the existence of a sympathetic functional reflex unit remains to be elucidated.

ISSN:0301-1569    

DOI:10.1159/000276296

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

This study aimed to investigate the origin of the free cells in the lumen of the endolymphatic sac (ES). Activation of the cells was accomplished through osmotic induction using glycerol. The ES and the perisaccular tissue were analyzed with special reference to the activity of periaqueductal bone marrow cells after different time intervals following the injection of hyperosmotic agents. The results show that the perisaccular or periaqueductal bone marrow space may constitute a source of some of the free cells occurring in the ES. Osmotic challenging of the inner ear may cause activation of the periaqueductal bone marrow, initiating the locomotion and migration of cells (mostly monocytes, neutrophils and eosinophilic leukocytes) along bone marrow sinusoids that frequently anastomose with the ES vessels. The free cells show signs of transepithelial diapedesis and, in the lumen of the ES, cells may develop into phagocytes which initiate the ingestion and degradation of secreted macromolecular aggregates. It is thought that osmotic alterations in the inner ear may give rise to local changes in or around the ES, leading to the chemotactic attraction of bone marrow cells. The results verify the existence of a complex sugar/protein aggregate metabolism over the wall of the ES, which is linked to the turnover of free cells. The findings may indicate that ES macrophages are important in the regulation of inner ear fluid homeostasis.

ISSN:0301-1569    

DOI:10.1159/000276297

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The pH value and the DC potential in the endolymphatic sac (ES) were measured using H+-selective double-barreled electrodes and the intra- and extradural approach, the pH value in the ES fluid (6.65 ± 0.12, n = 7) was markedly lower than that in the cerebrospinal fluid (7.39 ± 0.07, n = 7). Acidity in the ES fluid, under normal (nontreated) conditions may be closely associated with metabolism in the epithelium of the E

ISSN:0301-1569    

DOI:10.1159/000276298

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

A time sequence study was performed on experimental animals to investigate long-term effects of intravenously administered glycerol on the epithelial cell activity in the endolymphatic sac (ES) and on the ES volume. Fifteen to 60 min after systemic glycerol administration, the ES volume decreased. During this time, the ES lumen was often obliterated. Subsequently, the lumen dilated. Meanwhile, many light epithelial cells showed granules with floccular and/or lamellar contents. Concomitant deposition of floccular material into the luminal space suggested secretion of macromolecular substances, presumably from these transformed light cells. The number of granule-containing cells was significantly increased 2 h (p < 0.01) and 4 h (p < 0.01) after glycerol administration. The ES was significantly dilated after 4 h (p < 0.01) and 6 h (p < 0.05). Thus systemic alterations in osmotic pressure led to a reversible change in ES volume, with initial collapse followed by dilation and normalization after 8 h. The secretory response of the ES preceded the volume increase. A great variability in ES volume indicated high compliance of this organ system. A secretion/degradation system or turnover of osmotically active macromolecular complexes in the epithelial lining and ES lumen seems to be linked to the ability of the ES to hold fluid volumes within a wide range. This may serve as a micromechanical pressure-volume-regulating device for monitoring endolymph fluid homeostasis.

ISSN:0301-1569    

DOI:10.1159/000276299

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

There are indications that endolymphatic sac (ES) may be an immunologically active part of the inner ear. So far, no microorganisms or foreign substances have been localized in this area under ‘normal’ conditions. Only a limited number of human specimens, including the entire endolymphatic duct (ED) and ES, have been collected and analyzed from cadavers or surgical biopsy specimens. In this study, 6 human ED and ES collected from cadavers and at surgery were analyzed by light and electron microscopy. This was done in order to investigate if microorganisms may normally be drained at this route into the ES. Some microorganisms (Mycoplasma pneumoniae) were found in the lumen and subepithelial tissue of 1 human ED. These observations suggest that microorganisms may also be locally processed and disposed at the level of the ED. These results add further evidence as to the immunodefensive role of the human

ISSN:0301-1569    

DOI:10.1159/000276300

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The endolymphatic sac (ES) may play a crucial role in the pathophysiology of Ménière’s disease. This paper presents a technique to obtain and process fresh human specimens of the endolymphatic duct (ED) and the presumably more active intraosseous portion of the ES obtained at surgery. The specimens are preserved with an intact bony shell around the ED and the intraosseous ES. This allows ultrastructural histopathological evaluation of the intraluminal contents, the epithelium and the subepithelial tissue as well as the mutual relationships of these structures. Various factors influencing ES ultrastructure are discussed. The results obtained from this method may increase our understanding of the possible role of the ES in the etiology of different inner ear disord

ISSN:0301-1569    

DOI:10.1159/000276301

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

An age-related consecutive morphological analysis of the cochlea has been performed in homozygote (Je/Je) and heterozygote (je/+) jerker mouse mutants. A difference in the time of onset of hair cell pathology was evident between the two, but, when taking place, it showed a similar morphological type of degeneration. The cuticular plate and the stereocilia are particularly vulnerable structures and are the primary sites of damage. The suprastructures on both outer and inner hair cells disintegrate at the same time, irrespective of the level along the basilar membrane. During aging, the je/+ animals showed a progressive age-related impairment of auditory brainstem response thresholds which was correlated semiquantitatively to hair cell pathology.

ISSN:0301-1569    

DOI:10.1159/000276302

出版商:S. Karger AG    

年代:1992

数据来源: Karger