Casts and Crusts of the Tympanic Membrane

Weinberger, Jonathan; Proops, David W.; Hawke, Michael

doi:10.3109/00016488609108645

Cited by 5 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The underlying migrating epithelial cells are unable to transport layers and the cast is shed entire. 24 Histologically, these casts are remarkably similar to the tissue we observed surrounding extruded VTs and to that on the base of tympanostomy tubes removed during routine treatment of children for otitis media with effusion. 17 One third of our specimens contained identi able in ammatory cells within the keratin layers and adjacent to the VT surface indicating that the mechanisms involved in cast formation may play a role in extrusion, essentially the tube being shed into the external auditory canal surrounded by a 'cast'.…”

Section: Discussionsupporting

confidence: 70%

Histochemical, immunohistological and scanning electron microscope analysis of tissue retained on spontaneously extruded ventilation tubes

et al. 2002

View full text Add to dashboard Cite

The aim of this study was to analyse the tissue surrounding prematurely extruded ventilation tubes (grommets). Thirty-one ventilation tubes, including 21 Shah and six Shepherd tubes, that had been extruded naturally into the ear canal were examined. After formalin fixation, material adhering to the tubes was retrieved and processed to paraffin wax. Five tubes were processed for scanning electron microscope (SEM) analysis. Sections were stained using histochemical methods for collagen, keratin and keratohyaline. In addition, the presence of collagen (type I and III), keratin, vimentin, fibronectin, tenascin, factor VIII-related antigen, CD31 and CD45 was tested for by immunohistochemistry. Results showed that all specimens consisted of an acellular fibrous material, oriented in concentric rings parallel to the tube surface that was often associated with small collections of CD45+ inflammatory cells. Two specimens contained collagen that was detectable by histochemical and immunohistological methods. Twelve specimens contained identifiable desquamated epithelial cells containing keratin and keratohyaline. Only one specimen stained positively for connective tissue markers (vimentin, fibrous fibronectin, tenascin) or showed the presence of vascular epithelium. SEM revealed adherent clusters or sheets of plate-like structures, consistent with the presence of epithelial squames, on three of the five ventilation tubes examined. It is concluded that tissue retained on extruded grommets consists of orthokeratinitizing epithelium infiltrated by inflammatory cells, a finding that is consistent with the theory that tube extrusion occurs as a result of squamous epithelial proliferation, medial migration, differentiation and desquamation.

show abstract

Section: Discussionsupporting

confidence: 70%

Histochemical, immunohistological and scanning electron microscope analysis of tissue retained on spontaneously extruded ventilation tubes

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Although studies concerning the geological and geographical characters of Co‐rich crusts have been published for several decades (Weinberger et al ., ; Liang & Zhu, ), the microbial communities associated with these special areas have not been surveyed yet. For the first time, we investigated the bacterial and archaeal diversity in the deep‐sea sediment from a Co‐rich crust region by constructing 16S rRNA gene clone libraries.…”

Section: Introductionmentioning

confidence: 99%

Microbial diversity in deep-sea sediment from the cobalt-rich crust deposit region in the Pacific Ocean

Liao

Jiang

et al. 2011

FEMS Microbiol Ecol

View full text Add to dashboard Cite

Cobalt-rich crusts are important metallic mineral resources with great economic potential, usually distributed on seamounts located in the Pacific Ocean. Microorganisms are believed to play a role in the formation of crusts as well as in metal cycling. To explore the microbial diversity related to cobalt-rich crusts, 16S ribosomal RNA gene clone libraries were constructed from three consecutive sediment layers. In total, 417 bacterial clones were obtained from three bacterial clone libraries, representing 17 distinct phylogenetic groups. Proteobacteria dominated in the bacterial communities, followed by Acidobacteria and Planctomycetes. Compared with high bacterial diversity, archaea showed a remarkably low diversity, with all 137 clones belonging to marine archaeal group I except one novel euryarchaeotal clone. The microbial communities were potentially involved in sulfur, nitrogen and metal cycling in the area of cobalt-rich crusts. Sulfur oxidation and metal oxidation were potentially major sources of energy for this ecosystem. This is the first reported investigation of microbial diversity in sediments associated with cobalt-rich crusts, and it casts fresh light on the microbial ecology of these important ecosystems.

show abstract

Ototoxicity of Vasocidin Drops Applied to the Chinchilla Middle Ear

Brown

Wright²,

Masaki

et al. 1988

Archives of Otolaryngology - Head and Neck Surgery

View full text Add to dashboard Cite

\s=b\ Some widely used ototopical preparations are potentially toxic to the middle and inner ear. Vasocidin Ophthalmic Solution (sulfacetamide sodium and prednisolone sodium phosphate) has been advocated as an alternative agent that may have fewer toxic side effects in the treatment of otorrhea. Vasocidin was introduced into the bullae of nine chinchillas to investigate the effects on the middle and inner ear. The organ of Corti and stria vascularis were found to be entirely normal in 17 of the 18 temporal bones studied. Changes observed in the middle ears at one week included inflammation, hemorrhage, and effusion. Examination of specimens at four weeks revealed resolution of most of the inflammatory changes. The results of this experimental study indicate that Vasocidin causes reversible middle ear inflammation with little or no toxic effect on inner ear structures. TX 75235 (Dr Brown). phate as active ingredients) has recently been suggested as an alterna¬ tive preparation for treatment of otorrhea.5 Sulfacetamide, the antibi¬ otic used in Vasocidin, is a sulfonamide antimicrobial agent that is effective against a variety of grampositive and gram-negative microor¬ ganisms.6 Neither sulfacetamide nor the antiinflammatory agent predniso¬ lone is known to have ototoxic proper¬ ties. However, the possibility of oto¬ toxic side effects resulting from topi¬ cal application of Vasocidin to the middle ear cavity has not been experi¬ mentally tested. This study was designed to assess the morphologic effects of Vasocidin on the middle and inner ears of experimental animals following its application to the tym¬ panic cavity. MATERIALS AND METHODSEighteen temporal bones from nine young-adult chinchillas were evaluated following topical administration of Vaso¬ cidin to the middle ear cavity. Each chin¬ chilla received a single, bilateral applica¬ tion of Vasocidin, which contains sulfacet¬ amide sodium (100 mg/mL) and predniso¬ lone sodium phosphate (2.5 mg/mL) in a vehicle containing sodium edetate, boric acid, poloxamer 407, and thimerosal. Under ketamine hydrochloride anesthesia, 0.5 mL of the preparation was instilled directly into the middle ear cavity through a small hole placed in the superior aspect of the bulla. This route of administration was chosen to avoid damage to the tym¬ panic membrane or ossicular chain. Fol¬ lowing Vasocidin application, the experi¬ mental animals were kept alive for periods of either one week (six chinchillas) or four weeks (three chinchillas) before they were killed for histologie study of the temporal bones. Sham-operated control animals were not included, as previous experiments have documented that this does not cause middle or inner ear damage.7At the time specimens were taken for evaluation, the chinchillas were perfused via the aorta with a mixture of 1% paraformaldehyde and 2% glutaraldehyde in 0.1 mol/L cacodylate buffer at pH 7.4. The temporal bones were then removed from the skull and the middle ear cavities were opened for preliminary examination with an operating microscope...

show abstract

Casts and Crusts of the Tympanic Membrane

Cited by 5 publications

References 12 publications

Histochemical, immunohistological and scanning electron microscope analysis of tissue retained on spontaneously extruded ventilation tubes

Histochemical, immunohistological and scanning electron microscope analysis of tissue retained on spontaneously extruded ventilation tubes

Microbial diversity in deep-sea sediment from the cobalt-rich crust deposit region in the Pacific Ocean

Ototoxicity of Vasocidin Drops Applied to the Chinchilla Middle Ear

Contact Info

Product

Resources

About