1997 Fiscal Year Final Research Report Summary
The study of inflammatory and defensive mechanisms in otitis media with effusion.
| Project/Area Number |
07671872
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Sapporo Medical University |
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Principal Investigator |
HIMI Tetsuo Sapporo Medical University, School of Medicine, Associate Professor, 医学部, 助教授 (90181114)
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| Co-Investigator(Kenkyū-buntansha) |
HARABUCHI Yasuaki Sapporo Medical University, School of Medicine, Assistant Professor, 医学部, 講師 (80208686)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Otitis media / Cytokine / Chemokine / Neutrophil / Adhesion molecules |
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| Research Abstract |
In this project, in vivo induction and regulation of chemokine, cytokines and cell adhsion molecules in the middle ear were investigated using topical inoculation with KLH,lopopolysaccharide (LPS) and Lipoteichoic acid (LTA) in rat model. The expressions of mRNA in the middle ear mucosa was also examined.
At first, we examined the expression of cell adhesion molecules (CAM) in immune-mediated otitis media in the rat, as well as the regulation of these CAM in peripheral blood polymorphonuclear leukocytes (PMN) and lymphocytes upon exposure to middle ear effusion (MEE). The expression of CAM was important for the initiation of otitis media. Moreover, it ws thought that the interaction between the infiltrated PMN and MEE may modify the CAM's expression during the inflammatory process in the middle ear cavity.
Chemokine possesses chemotactic-activating properties toward neutrophils, and may contribute to the pathogenesis of middle ear inflammations. We investigated the production of chemokine in middle ear lavage and that gene expression in the middle mucosa using topical inoculation with LPS and LTA in the rat in vivo model. In contrtast to LPS as gram-negative endotoxin, lipoteichoic acid (LTA) is present within this layr of LPS as gram-negative endotoxin, lipoteichoic acid (LTA) is present within this layr of mo gram-positive bacteria. LTA has been shown to play a sigificant role in the initiation and progression of bacterial infection. Chemokine in middle ear lavage showed time-and dose-dependent production under LPS or LTA stimulation. At the time of peak production, the expression of cytokines and chemokine mRNA,evaluated using polymerase chain reaction, was considerable in the middle ear mucosa.
This investigation of the characteristics of proinflammatory cytokines in the middle ear cavity using rat in vivo model has extended the functional concept of cytokines at the initial stage otitis media.
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