chondroitin-sulfates and Otosclerosis

Otosclerotic bone has been observed to penetrate the endosteal layer of the cochlea, resulting in direct contact with the soft-tissue structures of the inner ear. Sensorineural hearing loss has been observed in some, but not all, of these cases. The development of histologic changes occurring in the cochlear soft tissues at the site of otosclerotic endosteal penetration has been descriptively referred to as a hyalinization reaction. The role of the hyalinization reaction in the development of hearing loss is unknown.. To evaluate the composition of these hyalinized soft tissues using immunostaining techniques.. Retrospective review in a human temporal bone histopathology research laboratory of 3 specimens from patients with endosteal otosclerotic involvement.. Evaluation of human temporal bone pathology findings.. Human temporal bone sections with endosteal otosclerotic involvement were studied using immunostaining techniques to identify collagen I, chondroitin sulfate, and keratan sulfate deposition in the hyalinization reaction tissue.. Intense collagen I staining was demonstrated within the hyalinization reaction in an onionskin-like layered fashion. In addition, dual immunofluorescence-stained sections for proteoglycans revealed both chondroitin sulfate and keratan sulfate deposition in the hyalinized tissue.. The tissue of the hyalinization reaction appears to be composed of collagen I, chondroitin sulfate, and keratan sulfate, which are known to act as molecular barriers. This observation suggests that the hyalinization reaction may limit the diffusion of toxic substances produced by otosclerotic bone into the soft tissues and fluids of the cochlea.

Topics: Aged, 80 and over; Chondroitin Sulfates; Cochlea; Collagen Type I; Female; Humans; Immunohistochemistry; Keratan Sulfate; Male; Microscopy, Confocal; Middle Aged; Otosclerosis; Retrospective Studies; Temporal Bone

Otosclerosis is a disease of hereditary liability. It might be related to an autosomal dominant inheritance. The genetic penetrance is determined by multifactorial influences. This paper was designed to study the reasonable strategies for prevention and treatment of this disease.. A retrospective review derived from data of the management and follow-up of 14 cases in 6 families. According to the special pathological features of active phase of the otospongiosis, the suitable strategies for prevention and treatment of this disease were suggested.. Diagnosis of 14 cases were confirmed by audiological, operative and/or pathological examinations. Eleven of fourteen cases underwent stapedectomy, in which 10 cases had the surgery on the ear with severer hearing loss, and one case on both sides. In all of the surgical cases, hearing levels improved significantly. Three cases have not yet received the stapedectomy, in which two cases scheduled for the surgery are currently treated by chondroitin sulfate and one case refused the surgical treatment due to financial shortage.. Examination of the ear function at regular intervals (6-12 months) is recommended for the adults among the family members with high-incidence of otosclerosis. Audiological and radiological examination play an important role in early diagnosis and treatment. Attention should be paid to the medicine for management and prevention of this disease. Stapedectomy is an optimal choice for clinical otosclerosis not only due to its capacity to improve the hearing level but also to prevent the advance of hearing loss. Hearing aid is the suitable choice if stapedectomy is contraindicated.

Topics: Audiometry; Chondroitin Sulfates; Female; Humans; Male; Otosclerosis; Retrospective Studies; Stapes Surgery

Chondroitin sulfate is a sulfated glycosaminoglycan that predominates in the ground substance of cartilage. Using monoclonal antichondroitin sulfate in 61 specimens of human otosclerotic lesions, we studied the distribution of this glucosaminoglycan in various stages of otosclerosis. Our findings show that chondroitin sulfate plays an important role in the development of otosclerosis. In addition, the distribution of chondroitin sulfate clearly delineates the stage of otosclerosis referred to as active into two distinct histologic stages. Dividing the active stage into "osteolytic" and "sponge-chondroid" would be reasonable based on our findings.

Topics: Cartilage; Chondroitin Sulfates; Fibroblasts; Humans; Immunoenzyme Techniques; Otosclerosis; Stapes

A study was carried out to obtain a more detailed picture of the phenotypes of human otosclerotic and normal bone cells and to analyse the response of both populations to treatment with TGF beta 1. Total collagen synthesis was found to be decreased, but fibronectin secretion increased in otosclerotic with respect to normal cells. Although overall glycosaminoglycan (GAG) synthesis was lower in otosclerotic cells, the sulphated GAG to hyaluronic acid (HA) ratio was higher, in particular there was greater expression of chondroitin (CS) and dermatan sulphates (DS). TGF beta 1 induced a more marked increase in collagen and fibronectin release and greater production of sulphated GAGs as DS and heparan sulphate (HS) in the otosclerotic cells. The fact that the phenotype of the otosclerotic cells differed from that of the normal cells and could be modified by TGF beta 1 treatment, suggests that TGF beta 1 is implicated in the pathogenesis of otosclerosis.

Topics: Bone and Bones; Cells, Cultured; Chondroitin Sulfates; Collagen; Dermatan Sulfate; Fibronectins; Glycosaminoglycans; Humans; Hyaluronic Acid; In Vitro Techniques; Otosclerosis; Phenotype; Transforming Growth Factor beta