Acute labyrinthitis associated with systemicCandida albicansinfection in ageing mice

1996 ◽  
Vol 110 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Robert B. Ashman ◽  
John M. Papadimitriou ◽  
Alma Fulurija
Keyword(s):  
Risk Factor ◽  
Candida Albicans ◽  
Inner Ear ◽  
Inbred Mice ◽  
Semicircular Canals ◽  
Systemic Infection ◽  
Opportunistic Pathogen ◽  
Scala Tympani ◽  
Membranous Labyrinth ◽  
Scala Vestibuli

AbstractThe yeastCandida albicansis an important opportunistic pathogen that has been associated with disease of the inner ear. This study describes the histopathology of acute labyrinthitis caused by systemic infection with C.albicansin ageing inbred mice. Within four days after infection, yeast and hyphal forms of C.albicanswere found in the membranous labyrinth. The utricle and the adjacent parts of the ampullary regions of the semicircular canals were most severely affected, but damage was also seen in the scala media, the Scala tympani, the saccule, and the scala vestibuli. In the utricle, the lining epithelium of the membranous labyrinth was disrupted, and the lining cells of the vestibular membrane showed foci in which the membrane was disrupted. The data suggest that age may represent a risk factor for fungal labyrinthitis.

Na and nonelectrolyte entry into inner ear fluids of the rat

1987 ◽  
Vol 253 (1) ◽  
pp. F50-F58 ◽  
Author(s):  
O. Sterkers ◽  
E. Ferrary ◽  
G. Saumon ◽  
C. Amiel
Keyword(s):  
Cerebrospinal Fluid ◽  
Inner Ear ◽  
Lateral Ventricle ◽  
Endothelial Barrier ◽  
Scala Tympani ◽  
Epithelial Secretion ◽  
Kinetics Of ◽  
Hydrophilic Solutes ◽  
Inner Ear Fluids ◽  
Scala Vestibuli

Kinetics of hydrophilic solute entry into endolymph (EL), perilymph (PL), and cerebrospinal fluid (CSF) were studied after intravenous administration (sodium, urea, glycerol, mannitol, sucrose) and cerebral lateral ventricle injection (urea, sucrose) of tracers in anesthetized rats. Samples of cochlear EL, PL of scala vestibuli (PLV), PL of scala tympani (PLT), and cisternal CSF were obtained. The data showed slow entry of tracers in PLV, PLT, and CSF as follows: Na greater than urea greater than mannitol approximately sucrose; slower entry of mannitol and sucrose in PLT and CSF than in PLV; 1 h delayed peak of radioactivity in PLV compared with the immediate peaks in PLT and CSF after CSF injection, and the value of PLV peak was 13% that in CSF; extremely slow entry of nonelectrolytes in EL. These results indicate that PLV originates mainly from plasma across a blood-perilymph barrier that restricts the entry of small hydrophilic solutes. The blood-perilymph barrier is most likely composed of an endothelial barrier associated with an epithelial secretion. The latter could be located at the vasculo-epithelial zone of the spiral limbus.

Computed Tomography and Magnetic Resonance Imaging of the Inner Ear

1988 ◽  
Vol 99 (5) ◽  
pp. 494-504 ◽  
Author(s):  
Robert K. Jackler ◽  
William P. Dillon
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Inner Ear ◽  
Semicircular Canals ◽  
Resonance Imaging ◽  
High Resolution Computed Tomography ◽  
Membranous Labyrinth ◽  
Prosthetic Devices ◽  
Ear Malformations

The majority of temporal bone radiographic studies are obtained either for middle ear and mastoid disease or in the evaluation of retrocochlear pathology. With recent technologic advances, diagnostic imaging of the inner ear has developed an increasing role in the evaluation and management of diseases that affect the cochlea, semicircular canals, and the vestibular and cochlear aqueducts. High-resolution computed tomography (CT) provides excellent detail of the osseous labyrinth, whereas magnetic resonance imaging (MRI) generates images derived from the membranous labyrinth and its associated neural elements. Optimal techniques for obtaining high quality CT and MRI images of the normal and diseased inner ear are presented. CT has proved useful in the evaluation of inner ear malformations, cochlear otosclerosis, labyrinthine fistulization from cholesteatoma, translabyrinthine fractures, otic capsule osteodystrophies, in the assessment of cochlear patency before cochlear implantation, and in the localization of prosthetic devices such as stapes wires and cochlear implants. While MRI produces discernible images of the soft tissue and fluid components of the inner ear, it has yet to demonstrate any unique advantages in the evaluation of inner ear disease. However, MRI produces excellent and highly useful images of the audiovestibular and facial nerves, cerebellopontine angle, and brain.

The ear

2021 ◽  
pp. 497-518
Author(s):  
Daniel R. van Gijn ◽  
Jonathan Dunne
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Middle Ear ◽  
Semicircular Canals ◽  
Lateral Wall ◽  
Oval Window ◽  
External Ear ◽  
Membranous Labyrinth ◽  
Stapes Footplate ◽  
Petrous Temporal Bone

The delicate yet definitive deflections of the pinna (wing/fin) of the external ear contribute to the collection of sound. The external acoustic meatus is responsible for the transmission of sounds to the tympanic membrane, which in turn separates the external ear from the middle ear. The middle ear is an air filled (from the nasopharynx via the eustachian tube), mucous membrane lined space in the petrous temporal bone. It is separated from the inner ear by the medial wall of the tympanic cavity – bridged by the trio of ossicles. The inner ear refers to the bony and membranous labyrinth and their respective contents. The osseus labyrinth lies within the petrous temporal bone. It consists of the cochlea anteriorly, semicircular canals posterosuperiorly and intervening vestibule – the entrance hall to the inner ear whose lateral wall bears the oval window occupied by the stapes footplate.

scholarly journals The Nuclear Receptor Nor-1 Is Essential for Proliferation of the Semicircular Canals of the Mouse Inner Ear

2002 ◽  
Vol 22 (3) ◽  
pp. 935-945 ◽  
Author(s):  
Tiia Ponnio ◽  
Quiana Burton ◽  
Fred A. Pereira ◽  
Doris K. Wu ◽  
Orla M. Conneely
Keyword(s):  
Inner Ear ◽  
Nuclear Receptor ◽  
Semicircular Canals ◽  
Mammalian Development ◽  
Genomic Locus ◽  
Membranous Labyrinth ◽  
Spatiotemporal Expression ◽  
Proliferative Growth ◽  
Precise Role

ABSTRACT Nor-1 belongs to the nur subfamily of nuclear receptor transcription factors. The precise role of Nor-1 in mammalian development has not been established. However, recent studies indicate a function for this transcription factor in oncogenesis and apoptosis. To examine the spatiotemporal expression pattern of Nor-1 and the developmental and physiological consequences of Nor-1 ablation, Nor-1-null mice were generated by insertion of the lacZ gene into the Nor-1 genomic locus. Disruption of the Nor-1 gene results in inner ear defects and partial bidirectional circling behavior. During early otic development, Nor-1 is expressed exclusively in the semicircular canal forming fusion plates. After formation of the membranous labyrinth, Nor-1 expression in the vestibule is limited to nonsensory epithelial cells localized at the inner edge of the semicircular canals and to the ampullary and utricular walls. In the absence of Nor-1, the vestibular walls fuse together as normal; however, the endolymphatic fluid space in the semicircular canals is diminished and the roof of the ampulla appears flattened due to defective continual proliferative growth of the semicircular canals.

Sodium and Potassium Concentrations in the Endolymph and Perilymph of the Cat

1974 ◽  
Vol 83 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Kazuo Makimoto ◽  
Herbert Silverstein
Keyword(s):  
Cerebrospinal Fluid ◽  
Inner Ear ◽  
Membrane Transport ◽  
Potassium Concentration ◽  
Sodium Concentration ◽  
Scala Tympani ◽  
Flame Photometer ◽  
Sodium And Potassium ◽  
Scala Vestibuli

Inner ear fluid from the scala vestibuli, scala tympani, scala media, utricle, and cerebrospinal fluid were collected from 47 normal cats, and analyzed for sodium and potassium concentrations with a flame photometer. Each compartment was found to have its own different values for sodium and potassium concentration. Perilymph in the scala vestibuli possesses a lower sodium concentration than perilymph in the scala tympani; in potassium concentration the perilymph in the scala vestibuli shows a higher value than that of the scala tympani. Compared with cochlear endolymph, utricular endolymph contains a higher concentration of sodium and a lower concentration of potassium. These concentration differences, which are related to the characteristics of membrane transport in each compartment of inner ear fluid, are considered to be adequate to sustain normal biological conditions of the inner ear.

Congenital Anomalies of the Inner Ear Introducing a New Classification of Labyrinthine Anomalies

1979 ◽  
Vol 88 (4_suppl2) ◽  
pp. 2-24 ◽  
Author(s):  
Susumu Suehiro ◽  
Isamu Sando
Keyword(s):  
Literature Review ◽  
Inner Ear ◽  
Classification System ◽  
Congenital Anomalies ◽  
Semicircular Canals ◽  
The Body ◽  
New Classification ◽  
Membranous Labyrinth ◽  
Ear Anomalies

In a literature review of 108 articles a special effort was made to find and classify inner ear anomalies and diseases associated with inner ear anomalies. This study showed the following. Most of the diseases associated with inner ear anomalies are also associated with anomalies in other parts of the body. Hereditary characteristics comprise the most common etiological factor among the diseases associated with inner ear anomalies. Among anomalies observed in the cochlea, the vestibule, and the semicircular canals, anomalies in the cochlea are most frequently associated with various diseases and were observed in 30 of 43 diseases. Anomalies of the vestibule were observed in 25 diseases, and those of the semicircular canals in 18 diseases. Anomalies in both the osseous and the membranous labyrinth were most frequently associated with the diseases studied, as they were observed to occur with 10 of the 43 diseases. In this paper a new classification system for labyrinthine anomalies is introduced, based on this study of the literature.

How Are Inner Ear Fluids Formed?

Physiology ◽  
1987 ◽  
Vol 2 (5) ◽  
pp. 176-179
Author(s):  
O Sterkers ◽  
E Ferrary ◽  
C Amiel
Keyword(s):  
Atpase Activity ◽  
Blood Plasma ◽  
Inner Ear ◽  
Scala Tympani ◽  
Inner Ear Fluids ◽  
Plasma Ultrafiltrate ◽  
Scala Vestibuli

The inner ear contains fluids that differ widely in composition and origin. The perilymph (in scala vestibuli and scala tympani) resembles a plasma ultrafiltrate, whereas the endolymph (in scala media) is a K+-rich fluid. The precursor of perilymph is blood plasma. The formation of endolymph proceeds from perilymph, is dependent on Na+-K+-ATPase activity, and also appears to involve a still unidentified electrogenic K+-transporting system.

Hyaluronan as a propellant for epithelial movement: the development of semicircular canals in the inner ear of Xenopus

Development ◽  
1991 ◽  
Vol 112 (2) ◽  
pp. 541-550 ◽  
Author(s):  
C.M. Haddon ◽  
J.H. Lewis
Keyword(s):  
Extracellular Matrix ◽  
Hyaluronic Acid ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Otic Vesicle ◽  
Membranous Labyrinth ◽  
The Core ◽  
Secondary Palate

The membranous labyrinth of the inner ear, with its three semicircular canals, originates from a simple spheroidal otic vesicle. The process is easily observed in Xenopus. The vesicle develops three dorsal outpocketings; from the two opposite faces of each outpocketing pillars of tissue are protruded into the lumen; and these paired ‘axial protrusions’ eventually meet and fuse, to form a column of tissue spanning the lumen of the outpocketing like the hub of a wheel, with a tube of epithelium forming the semicircular canal around the periphery. Each axial protrusion consists of epithelium encasing a core of largely cell-free extracellular matrix that stains strongly with alcian blue. In sections, at least 60% of the stainable material is removed by treatment with Streptomyces hyaluronidase. When Streptomyces hyaluronidase is microinjected into the core of a protrusion in vivo, the protrusion collapses and the corresponding semicircular canal fails to form. Hyaluronan (hyaluronic acid) in the core of the protrusion therefore seems to be essential in driving the extension of the protrusion. Autoradiography with tritiated glucosamine indicates that the hyaluronan-rich matrix is synthesised by the epithelium covering the tip of the protrusion; the basal lamina here appears to be discontinuous. These findings indicate that the epithelium of the axial protrusion propels itself into the lumen of the otocyst by localised synthesis of hyaluronan. Hyaluronan may be used in a similar way in the development of other organs, such as the heart and the secondary palate.

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