| 1. |
- Emgård, Per, et al.
(författare)
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An animal model for external otitis.
- 1997
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Ingår i: European Archives of Oto-Rhino-Laryngology. - 0937-4477 .- 1434-4726. ; 254:3, s. 115-119
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Tidskriftsartikel (refereegranskat)abstract
- External otitis was produced in 12 Sprague-Dawley rats by mechanical stimulation through a plastic micropipette inserted into the right external auditory canal (EAC). The EAC was later evaluated regarding the color of the skin, swelling and the presence of fluid. Within 1 day all rats developed an external otitis that was characterized by a red, swollen ear canal containing an opalescent fluid. The tympanic membrane and middle ear cavity appeared to be normal. No healed EACs were seen within the initial 10 days of follow-up and 4 of 6 rats still exhibited external otitis at day 21. Light microscopy of biopsy specimens revealed pronounced edema of the dermis of the ear canal. Mast cells were more numerous in the early phase of the otitis present, although very few inflammatory cells were found in tissues despite the marked inflammatory reaction produced. Findings show that this animal model for external otitis can be used to investigate pathogenesis as well as to test various treatment strategies.
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| 2. |
- Kakoi, Hiroyuki, et al.
(författare)
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Morphological changes in rat submandibular gland mucous cells during fixation with 10% formalin
- 1996
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Ingår i: European Archives of Oto-Rhino-Laryngology. - 0937-4477 .- 1434-4726. ; 253:4-5, s. 214-21
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Tidskriftsartikel (refereegranskat)abstract
- The features of mucous cells in 10% formalin (FA)-fixed submandibular glands differ markedly from those fixed in glutaraldehyde (GA). We therefore studied morphological changes in mucous cells during 10% FA fixation. Mucous cells were fixed in either 10% FA, neutral sodium-phosphate-buffered (Na-PBed) 10% FA, ice-cold 10% FA or an ice-cold fixative mixture of 2.0% paraformaldehyde (PA) and 0.5% GA. Two different methods were used: immersion fixation and venous perfusion fixation. The 10% FA-fixed tissues had elliptical or flattened nuclei, a clear cytoplasm and no secretory granules. Tissues fixed with the fixative mixture displayed almost round nuclei, a broad endoplasmic reticulum and abundant secretory granules in the cytoplasm. Tissues immersion-fixed with neutral Na-PBed 10% FA or perfusion-fixed with ice-cold 10% FA had almost the same light microscopic appearance as that of the mixture-fixed tissues. To elucidate the process of morphological changes during 10% FA fixation at room temperature, samples immersed in 10% FA for varying periods of time were postfixed immediately in the fixative mixture and exposed to microwave irradiation. This method produced a variety of findings, even within the same section. There was a significant difference in the findings seen in the center of the section and at the periphery. The initial changes caused by 10% FA were rupture of the secretory granules located in the perinuclear region and destruction of the perinuclear organelles such as Golgi apparatus, mitochondria and endoplasmic reticulum. Absorption of the endoplasmic reticulum progressed so that the perinuclear region became translucent. To obtain a better structure in mucous cells from the fixed submandibular gland tissues, an appropriate fixative such as GA should be used and the fixative should infiltrate into the tissues as quickly as possible.
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| 3. |
- Stenqvist, Monika, et al.
(författare)
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Middle ear mucosa changes following exposure to Pseudomonas aeruginosa exotoxin A
- 1999
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Ingår i: European Archives of Oto-Rhino-Laryngology. - : Springer Science and Business Media LLC. - 0937-4477 .- 1434-4726. ; 256:10, s. 484-90
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Tidskriftsartikel (refereegranskat)abstract
- Pseudomonas aeruginosa exotoxin A (1 microgram/20 microliters) was instilled into the middle ear cavity in the rat. Morphological changes of the mucosa were analyzed after various intervals using light (LM) and transmission electron microscopy (TEM). An inflammatory cell reaction was seen in which there was a predominance of polymorphonuclear leukocytes (PMNs) and mononuclear cells that were mostly lymphocytes and monocytes/macrophages. Epithelial cells often showed signs of metaplasia and hyperplasia, followed by degradation through necrosis and/or apoptosis, resulting in denudation of the submucosal layer. A characteristic feature was the physical interaction between intraepithelial lymphocytes and epithelial cells. Lymphocytes adhering to the cell coat of epithelial cells showed signs of directed secretion that seemed to end in necrosis or apoptosis of the target cell. These changes occurred simultaneously with phagocytosis of cells and cell debris by PMNs and macrophages. Ultrastructural analysis suggested that intraepithelial, lymphocyte-mediated cytolysis and apoptosis may be important events in degradation of the epithelium following exposure to Pseudomonas sp. exotoxin. These findings indicate that denuding of the lamina propria may facilitate the penetration of toxin into the labyrinth, thus explaining subsequent inner ear damage.
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| 4. |
- Takumida, Masaya, et al.
(författare)
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Lipopolysaccharide-induced expression of nitric oxide synthase II in the guinea pig vestibular end organ
- 1998
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Ingår i: European Archives of Oto-Rhino-Laryngology. - : Springer Science and Business Media LLC. - 0937-4477 .- 1434-4726. ; 255:4, s. 184-8
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the investigation was to ascertain whether inoculation of bacterial lipopolysaccharide (LPS) into the vestibular organ of the guinea pig might induce formation of nitric oxide synthase (NOS) II. Forty-eight hours after the animals were injected with 1 mg transtympanic LPS, varying degrees of impaired caloric responses were observed with similar degeneration of vestibular hair cells. These effects could be blocked with N-nitro-L-arginine methylester, a competitive inhibitor of NOS. Findings suggested that NOS II, which was not normally detectable in the guinea pig vestibular organ but was present following inoculation of LPS, produced the nitric oxide as the toxic factor causing cell damage. If true, LPS may represent a reproducible method for studying the vestibular pathogenesis of inner ear disease.
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| 5. |
- Golusinski, W, et al.
(författare)
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Alteration of p53 gene structure and function in laryngeal squamous cell cancer
- 1997
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Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - 0937-4477. ; 254254 Suppl 1, s. S133-S137
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Tidskriftsartikel (refereegranskat)
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| 10. |
- YAMASHITA, H, et al.
(författare)
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Expression of S-100 protein in the human fetal inner ear
- 1995
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Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - 0937-4477. ; 252:5, s. 312-315
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