Fine Structure Histopathology of Labyrinthitis Ossificans in the Gerbil Model

2005 ◽  
Vol 114 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Steven P. Tinling ◽  
Vishad Nabili ◽  
Hilary A. Brodie

Labyrinthitis ossificans (LO) is the pathological deposition of new bone within the lumen of the cochlea and labyrinth. This process occurs most commonly as a result of infection or inflammation affecting the otic capsule. Trauma and vascular compromise can also lead to neo-ossification within the otic capsule. The mechanism that regulates this process remains unestablished. This study details the end-stage histopathology in high-resolution plastic thin sections. Twenty Mongolian gerbils were infected by intrathecal injection of Streptococcus pneumoniae type 3 followed by subcutaneous penicillin G procaine (8 days) and were painlessly sacrificed 3 months later. The cochleas were serially divided and sectioned for light and electron microscopy. Sixteen of 20 animals (27 of 40 cochleas) demonstrated LO. Cochlear damage was most extensive in the vestibule and basal turn and decreased toward the apex, which often appeared normal. The histopathologic findings consisted of 1) new bone, calcospherites, osteoid, and fibrosis without dense connective tissue or osteoblasts extending from the endosteal wall into the lumen of the vestibule and scala tympani; 2) areas of dense connective tissue and osteoid enclosed by epithelial cells conjoined with the organ of Corti, stria vascularis, spiral ligament, and vestibular (Reissner's) membrane; and 3) partial to complete loss of the organ of Corti, spiral ligament cell bodies, stria vascularis, and spiral ganglion cells. Osteoblastic activity was not demonstrated in end-stage ossification in LO in the gerbil model. Neoossification appears to occur by calcospherite deposition along collagen-like fibrils within osteoid. The destruction of the organ of Corti, spiral ganglion cells, stria vascularis, and cells of Reissner's membrane and the spiral ligament occurs even in the absence of ossification of the cochlear duct.

2015 ◽  
Vol 20 (4) ◽  
pp. 267-272 ◽  
Author(s):  
Joseph B. Nadol Jr ◽  
Jan D. Marshall ◽  
Roderick T. Bronson

Alström's syndrome is an autosomal recessive syndromic genetic disorder caused by mutations in the ALMS1 gene. Sensorineural hearing loss occurs in greater than 85% of patients. Histopathology of the inner ear abnormalities in the human has not previously been fully described. Histopathology of the inner ear in Alström's syndrome is presented in 2 genetically confirmed cases. The predominant histopathologic correlates of the sensorineural loss were degeneration of the organ of Corti, both inner and outer hair cells, degeneration of spiral ganglion cells, and atrophy of the stria vascularis and spiral ligament.


Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 399 ◽  
Author(s):  
Jhang Ho Pak ◽  
Junyeong Yi ◽  
Sujin Ryu ◽  
In Ki Kim ◽  
Jung-Woong Kim ◽  
...  

Free radicals formed in the inner ear in response to high-intensity noise, are regarded as detrimental factors for noise-induced hearing loss (NIHL). We reported previously that intraperitoneal injection of cobalt chloride attenuated the loss of sensory hair cells and NIHL in mice. The present study was designed to understand the preconditioning effect of CoCl2 on oxidative stress-mediated cytotoxicity. Treatment of auditory cells with CoCl2 promoted cell proliferation, with increases in the expressions of two redox-active transcription factors (hypoxia-inducible factor 1α, HIF-1α, nuclear factor erythroid 2-related factor 2; Nrf-2) and an antioxidant enzyme (peroxiredoxin 6, Prdx6). Hydrogen peroxide treatment resulted in the induction of cell death and reduction of these protein expressions, reversed by pretreatment with CoCl2. Knockdown of HIF-1α or Nrf-2 attenuated the preconditioning effect of CoCl2. Luciferase reporter analysis with a Prdx6 promoter revealed transactivation of Prdx6 expression by HIF-1α and Nrf-2. The intense immunoreactivities of HIF-1α, Nrf-2, and Prdx6 in the organ of Corti (OC), spiral ganglion cells (SGC), and stria vascularis (SV) of the cochlea in CoCl2-injected mice suggested CoCl2-induced activation of HIF-1α, Nrf-2, and Prdx6 in vivo. Therefore, we revealed that the protective effect of CoCl2 is achieved through distinctive signaling mechanisms involving HIF-1α, Nrf-2, and Prdx6.


2008 ◽  
Vol 122 (11) ◽  
pp. 1151-1155 ◽  
Author(s):  
R Ramírez-Camacho ◽  
J R García-Berrocal ◽  
A Trinidad ◽  
J M Verdaguer ◽  
J Nevado

AbstractIntroduction:The ototoxic effects of cisplatin include loss of outer hair cells, degeneration of the stria vascularis and a decrease in the number of spiral ganglion cells. Scanning microscopy has shown balloon-like protrusions (blebs) of the plasma membrane of inner hair cells following cisplatin administration. The present study was undertaken to identify the possible role of inner and outer hair cell blebs in the pathogenesis of cisplatin-induced ototoxicity.Materials and methods:Twenty-five guinea pigs were injected with cisplatin and their hearing tested at different time-points, before sacrifice and examination with scanning electron microscopy.Results and analysis:Seven animals showed blebs in the inner hair cells at different stages. Hearing thresholds were lower in animals showing blebs.Discussion:Cisplatin seems to be able to induce changes in inner hair cells as well as in other structures in the organ of Corti. Blebbing observed in animals following cisplatin administration could play a specific role in the regulation of intracellular pressure.


1974 ◽  
Vol 83 (2) ◽  
pp. 202-215 ◽  
Author(s):  
Robert A. Schindler ◽  
Michael M. Merzenich

The temporal bones of ten cats implanted with intracochlear electrodes for three to 117 weeks were stained with hematoxylin and eosin and examined with light microscopy. The electrodes were embedded in Silastic® which was molded to fill the most basal 9 mm of the scala tympani. They were inserted directly into the scala through the round window. Among our observations were the following: 1) All or nearly all hair cells were lost in the basal coil during the first several weeks after implantation. Some, but not all, supporting cells were also lost. There was extensive hair cell loss in the middle and apical turns, although some hair cells were seen there in all examined cats. 2) There was evidence of degeneration of spiral ganglion cells in the basal cochlea in several animals, but most primary auditory neurons including (with two exceptions) most of those in the region directly over the electrode, survived implantation in every cat. The radial nerve fibers of the spiral ganglion cells also survived long-term implantation. The functional viability of remaining spiral ganglion cells was confirmed in acute neurophysiological experiments conducted just before the animals were sacrificed. 3) More severe degeneration was seen in two cats in which the electrode perforated the basilar partition. In these animals, there was loss of many spiral ganglion cells, and evidence of new bone growth in the region of the perforation. 4) The appearance of the stria vascularis and spiral ligament in some implanted animals paralleled their descriptions following occlusion of the cochlear vein. 5) Connective tissue formed around the electrode surfaces, apparently displacing perilymph and sealing the electrode into the scala tympani. There was no evidence of perilymph fistula in any animal. 6) There was little evidence of progressive degeneration of the organ of Corti or spiral ganglion from three to 34 weeks after implantation. Some of the implications and limitations of these findings are discussed.


1976 ◽  
Vol 85 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Fumiro Suga ◽  
John R. Lindsay

Temporal bone histopathology of 17 aged patients who had spontaneous and gradually progressive bilateral sensorineural hearing losses associated with aging was studied. Six cases in the present material showed the gradually sloping audiometric curve; nine cases, abrupt high tone hearing loss; and two cases, the flat audiometric curve. The most prominent histopathological change in the inner ear was a decrease in the population of the spiral ganglion cells. However, diffuse senile atrophy was also often seen in the organ of Corti and the stria vascularis. A positive correlation between the degree of arteriosclerosis and the degree of sensorineural degeneration in the cochlea was not obtained in the present cases. Also, the correlation was not found to be consistent between the type of the audiometric curve and the localization of lesions in the sensory, the neural or the vascular elements in the cochlea. Our observations show that a certain type of audiometric curve does not necessarily indicate a lesion in a specific cochlear element.


1982 ◽  
Vol 91 (3) ◽  
pp. 250-255 ◽  
Author(s):  
Yasuya Nomura ◽  
Shigeo Mori ◽  
Mineko Tsuchida ◽  
Teruhisa Sakurai

We present a histopathological study of a 44-year-old female with essential cryoglobulinemia. She had suffered from purpura and ulcer in winter, bilateral tinnitus and progressive hearing loss. An audiogram taken a week before her death showed bilateral total deafness. In the cochlea of the left temporal bone, the organ of Corti was either missing or present as a mound. The stria vascularis was atrophic throughout the cochlea. The tectorial membrane showed drooping and encapsulation. Reissner membrane was in the normal position. Eosinophilic precipitate was noted in the scala media at the site where Reissner membrane bulged. The spiral ganglion cells were well preserved. In the lower basal turn, there was fibrosis and ossification intermingled in the scala tympani. Ossification was most marked near the basal end. The semicircular canals and vestibule were almost totally ossified and fused with surrounding bone. There was a small, cyst-like structure in the vestibule containing eosinophilic fluid. Our findings indicate that the deafness was the result of circulatory disturbance due to cryoglobulinemia. To our knowledge, this is the first cryoglobulinemia case in which temporal bone findings are reported.


1989 ◽  
Vol 98 (5) ◽  
pp. 359-363 ◽  
Author(s):  
Patricia A. Schachern ◽  
Michael M. Paparella ◽  
Donald A. Shea ◽  
Tae H. Yoon

Fabry's disease is a rare progressive X-linked recessive disorder of glycosphingolipid metabolism. The accumulation of glycosphingolipids occurs in virtually all areas of the body, including the endothelial, perithelial, and smooth-muscle cells of blood vessels, the ganglion cells of the autonomic nervous system, and the glomeruli and tubules of the kidney. Although otologic symptoms have been described in these patients, to our knowledge there have been no temporal bone histopathologic reports. We describe the clinical histories, audiometric results, and temporal bone findings of two patients with this rare disorder. Both patients demonstrated a bilateral sloping sensorineural hearing loss audiometrically. Middle ear findings of seropurulent effusions and hyperplastic mucosa were seen in all four temporal bones. Strial and spiral ligament atrophy in all turns, and hair cell loss mainly in the basal turns, were also common findings. The number of spiral ganglion cells was reduced in all temporal bones; however, evidence of glycosphingolipid accumulation was not observed in the spiral ganglia.


1978 ◽  
Vol 87 (3) ◽  
pp. 399-403 ◽  
Author(s):  
H. K. Chandra Sekhar ◽  
Nobuhtro Toktta ◽  
S. Alexic ◽  
M. Sachs ◽  
John F. Daly

— The temporal bone findings in a case of hemifacial microsomia are described with photographs. The right facial hypoplasia was associated with anophthalmia and microtia on the same side. The right petrous bone was hypoplastic and showed total superior dehiscence of the internal acoustic meatus. The otic capsule was deformed with an underdeveloped cochlear modiolus grossly deficient in spiral ganglion population. The spiralling cochlear shell showed partial deficiency of the interscalar septum between the middle and apical coils. The cochlear duct was shorter than that on the normal side; the organ of Corti however was normal. The vestibular system did not show any structural abnormality except for the degeneration and reduction of the Scarpa's ganglion cells and nerve fibers. An additional interesting fact was that the facial nerve was totally absent in the temporal bone except for its nervus intermedius component.


2003 ◽  
Vol 51 (7) ◽  
pp. 903-912 ◽  
Author(s):  
Toshihiro Suzuki ◽  
Tetsuro Takamatsu ◽  
Masahito Oyamada

To elucidate whether the two different gap junction proteins connexin43 (Cx43) and connexin26 (Cx26) are expressed and localized in a similar manner in the adult rat cochlea, we performed three-dimensional confocal microscopy using cryosections and surface preparations. In the cochlear lateral wall, Cx43-positive spots were localized mainly in the stria vascularis and only a few spots were present in the spiral ligament, whereas Cx26-positive spots were detected in both the stria vascularis and the spiral ligament. In the spiral limbus, Cx43 was widely distributed, whereas Cx26 was more concentrated on the side facing the scala vestibuli and in the basal portion. In the organ of Corti, Cx43-positive spots were present between the supporting cells but they were fewer and much smaller than those of Cx26. These data demonstrated distinct differences between Cx43 and Cx26 in expression and localization in the cochlea. In addition, the area of overlap of zonula occludens-1 (ZO-1) immunolabeling with Cx43-positive spots was small, whereas it was fairly large with Cx26-positive spots in the cochlear lateral wall, suggesting that the differences are not associated with the structural difference between carboxyl terminals, i.e., those of Cx43 possess sequences for binding to ZO-1, whereas those of Cx26 lack these binding sequences.


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