Stria Ultrastructure and Vessel Transport in Acoustic Trauma

1974 ◽  
Vol 83 (4) ◽  
pp. 498-514 ◽  
Author(s):  
Arndt J. Duvall ◽  
W. Dixon Ward ◽  
Kathryn E. Lauhala

One hundred and ten chinchillas were exposed to a 700–2800 Hz noise at 123 dB for 15 minutes. A consistent pattern of ultrastructural pathology within the lateral cochlear wall was found. Significant damage to the stria vascularis was first observed one hour postexposure, reached a peak at 24 hours, and had recovered almost completely by 28 days. Spiral prominence damage was permanent. The pathology included stria widening, temporary disappearance of intermediate cells, alterations of the internal membrane system and abnormal vessel transport. Horseradish peroxidase (HRP) was employed as an indicator of transport from vessels. Transport from the stria vessels was absent when stria ultrastructural abnormality was at a maximum; at other postexposure times, however, abnormally rapid exodus of HRP from the vessels of the stria was observed in animals who had received intravenous injections of HRP 30 seconds prior to sacrifice. On the other hand, no leakage was observed in the animals injected one minute before sacrifice. Theories to explain this transport dichotomy are proposed.

1986 ◽  
Vol 95 (3) ◽  
pp. 309-312 ◽  
Author(s):  
Kensuke Watanabe

Capillaries entering and leaving the stria vascularis were surrounded by layers of basal cells and fibrocytes. The entering capillaries were surrounded by one or two thin basal cells, while the leaving capillaries were surrounded by four or five thicker and interdigitated basal cell layers. Moreover, the layers surrounding the leaving capillaries persisted further into the spiral ligament. Two kinds of filaments were observed in the basal cells, one thin and the other thick. Capillaries were observed to leak horseradish peroxidase before they entered and after they left the stria vascularis. Although the reaction product of horseradish peroxidase was observed in all perivascular spaces of leaving capillaries, very little or no reaction product was observed around some entering capillaries. It is speculated that the layers of basal cells and fibrocytes around entering and leaving capillaries control the vascular flow out of the stria vascularis, although the layers around leaving capillaries may be more contractile than those around entering capillaries.


1997 ◽  
Vol 106 (5) ◽  
pp. 394-398 ◽  
Author(s):  
Kensuke Watanabe ◽  
Yasuo Tanaka

Escherichia coli-derived endotoxin was inoculated in the middle ear of guinea pigs 24 hours after being injected intraperitoneally. Twenty-four hours after the middle ear inoculation, horseradish peroxidase (HRP) was injected via the femoral vein and the permeability of HRP through the capillaries of the stria vascularis and the destination of the leaked HRP were examined. A large amount of HRP leaked out of the capillary through the opened endothelial cell junctions and penetrated the enlarged intercellular spaces. Leaked HRP entered the pinocytotic vesicles of the intermediate cells. Even slightly degenerated intermediate cells retained this function. The HRP penetrated the spongelike structure of the marginal cells leading to the intercellular space. This structure was not observed without endotoxin. The HRP could not pass to the cochlear duct through the tight junctions between marginal cells. Blood sludging was observed in the strial capillaries. It appeared more frequently in the upper three turns than in the basal turn. The HRP leakage out of the capillaries was observed not only in the upper three turns but also in the basal turn.


Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.


Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 453-463 ◽  
Author(s):  
K.P. Steel ◽  
C. Barkway

The stria vascularis of the mammalian cochlea is composed primarily of three types of cells. Marginal cells line the lumen of the cochlear duct and are of epithelial origin. Basal cells also form a continuous layer and they may be mesodermal or derived from the neural crest. Intermediate cells are melanocyte-like cells, presumably derived from the neural crest, and are scattered between the marginal and basal cell layers. The marginal cells form extensive interdigitations with the basal and intermediate cells in the normal adult stria. The stria also contains a rich supply of blood vessels. We investigated the role of melanocytes in the stria vascularis by studying its development in a mouse mutant, viable dominant spotting, which is known to have a primary neural crest defect leading to an absence of recognisable melanocytes in the skin. Melanocytes were not found in the stria of most of the mutants examined, and from about 6 days of age onwards a reduced amount of interdigitation amongst the cells of the stria was observed. These ultrastructural anomalies were associated with strial dysfunction. In the normal adult mammal, the stria produces an endocochlear potential (EP), a resting dc potential in the endolymph in the cochlear duct, which in mice is normally about +100 mV. In our control mice, EP rose to adult levels between 6 and 16 days after birth. In most of the mutants we studied, EP was close to zero at all ages from 6 to 20 days. Melanocyte-like cells appear to be vital for normal stria vascularis development and function. They may be necessary to facilitate the normal process of interdigitation between marginal and basal cell processes at a particular stage during development, and the lack of adequate interdigitation in the mutants may be the cause of their strial dysfunction. Alternatively, melanocytes may have some direct, essential role in the production of an EP by the stria. Melanocytes may be important both for normal strial development and for the production of the EP. We believe this is the clearest demonstration yet of a role for migratory melanocytes other than their role in pigmentation.


1931 ◽  
Vol 31 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Leonard S. Dudgeon ◽  
H. K. Goadby

1. The tissue reactions in rabbits from intravenous injections of live and dead Staphylococcus aureus and massive doses of indian ink and colloidal silver have been studied.2. Any particles injected into the circulation cause the accumulation of polymorphs in the lung capillaries.3. Inert colloidal particles such as indian ink are clumped in the capillaries of the lungs, liver, spleen and kidneys, and are phagocytosed by the endothelial cells.4. Staphylococci (S. aureus), live or dead, are nearly all held up in the lungs, where they are actively phagocytosed by the polymorphs within 5 minutes of an intravenous injection.5. Subsequently the cocci are distributed to the other organs, where phagocytosis continues mainly by polymorphs, but in the liver also by the Kupfer cells.6. Special attention is drawn to the localisation of the cocci in certain areas in the kidneys.7. Platelet counting on animals injected with various substances showed that there is an agglomeration of the particles with the platelets, which are consequently removed from the circulation.8. In the case of the inert particles the platelets are then restored to the circulation. With organisms (S. aureus) some of the platelets appear to be completely removed from the blood together with the bacteria.


1971 ◽  
Vol 8 (2) ◽  
pp. 146-174 ◽  
Author(s):  
A. Kast ◽  
M. Herbst ◽  
L. Stoll

The ability of intravenous injections of single and mixed cultures of streptococci of types A, C, D, E, G, and N, of S. viridans and of E. rhusiopathiae of serotypes A and B, to cause endocarditis in rats was tested. A mixed culture of three strains of Erysipelothrix was particularly effective, especially in male rats, whereas in all the other experiments, bacterial endocarditis seldom occurred. The endocarditis was a consequence of vasculitis and myocarditis. In most cases of valvular endocarditis subendothelial edema caused detachment of endothelial cells and provided the environment for bacterial colonisation of the valves.


2020 ◽  
Vol 49 (4) ◽  
pp. 931-937
Author(s):  
Xunbing Huang ◽  
Yueyue Wang ◽  
Zehua Zhang

Abstract Erythroneura sudra is a leafhopper occurring in northern China, which causes significant damage to fruit. The relationships between E. sudra and five fruit tree species (Rosaceae) were studied for 3 yr. The highest relative density of E. sudra was recorded on leaves of Amygdalus persica L. and Cerasus pseudocerasus Lindl. Likewise, it had the highest survival rate and shortest developmental time when it fed on these two plants species, indicating that they were the most preferred by E. sudra than the other plant species. The relative density and growth performance of E. sudra were negatively correlated with the levels of tannins and flavonoids in the leaves of the host species. Both plant species had relatively lower flavonoids and tannins, and this may have contributed to the enhanced survival and population growth of E. sudra. These results can guide the development of improved management strategies for this pest.


ORL ◽  
1998 ◽  
Vol 60 (6) ◽  
pp. 314-317 ◽  
Author(s):  
Chuan-Jen Hsu ◽  
Tien-Chen Liu ◽  
Kai-Nan Lin

1992 ◽  
Vol 5 (1) ◽  
pp. 30-37 ◽  
Author(s):  
MICHAEL ANNE GRATTON ◽  
CHARLES G. WRIGHT

2002 ◽  
Vol 282 (2) ◽  
pp. C403-C407 ◽  
Author(s):  
Daniel C. Marcus ◽  
Tao Wu ◽  
Philine Wangemann ◽  
Paulo Kofuji

Stria vascularis of the cochlea generates the endocochlear potential and secretes K+. K+ is the main charge carrier and the endocochlear potential the main driving force for the sensory transduction that leads to hearing. Stria vascularis consists of two barriers, marginal cells that secrete potassium and basal cells that are coupled via gap junctions to intermediate cells. Mice lacking the KCNJ10 (Kir4.1) K+ channel in strial intermediate cells did not generate an endocochlear potential. Endolymph volume and K+ concentration ([K+]) were reduced. These studies establish that the KCNJ10 K+ channel provides the molecular mechanism for generation of the endocochlear potential in concert with other transport pathways that establish the [K+] difference across the channel. KCNJ10 is also a limiting pathway for K+ secretion.


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