The Presence of Platelet-Activating Factor-Acetylhydrolase in Human Middle Ear Effusions

Tsuji, Hiroyuki; Furukawa, Masayuki; Ikeda, Hiroki; Asako, Mikiya; Yamashita, Toshio

doi:10.1159/000027558

Cited by 5 publications

(3 citation statements)

References 17 publications

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“…PAF induces neutrophil adhesion to endothelial cells (137). In addition, PAF appears to play a major role in the production of MEE by increasing vascular permeability, stimulating epithelial secretory activity, and reducing the mucociliary activity of the middle ear causing eustachian tube dysfunction (140). By stimulating mucous glycoprotein release, PAF appears to be a mediator in the hypersecretion of mucus in the middle ear cavity and eustachian tube (141).…”

Section: Inflammation and Ommentioning

confidence: 99%

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

Juhn

Jung

Hoffman

et al. 2008

Clin Exp Otorhinolaryngol

137

148

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This review deals with the characteristics of various inflammatory mediators identified in the middle ear during otitis media and in cholesteatoma. The role of each inflammatory mediator in the pathogenesis of otitis media and cholesteatoma has been discussed. Further, the relation of each inflammatory mediator to the pathophysiology of the middle and inner ear along with its mechanisms of pathological change has been described. The mechanisms of hearing loss including sensorineural hearing loss (SNHL) as a sequela of otitis media are also discussed. The passage of inflammatory mediators through the round window membrane into the scala tympani is indicated. In an experimental animal model, an application of cytokines and lipopolysaccharide (LPS), a bacterial toxin, on the round window membrane induced sensorineural hearing loss as identified through auditory brainstem response threshold shifts. An increase in permeability of the blood-labyrinth barrier (BLB) was observed following application of these inflammatory mediators and LPS. The leakage of the blood components into the lateral wall of the cochlea through an increase in BLB permeability appears to be related to the sensorineural hearing loss by hindering K+ recycling through the lateral wall disrupting the ion homeostasis of the endolymph. Further studies on the roles of various inflammatory mediators and bacterial toxins in inducing the sensorineumral hearing loss in otitis media should be pursued.

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Section: Inflammation and Ommentioning

confidence: 99%

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

Juhn

Jung

Hoffman

et al. 2008

Clin Exp Otorhinolaryngol

137

148

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show abstract

“…With respect to biochemical properties, PAF‐AH in CSF was different from other known acetylhydrolases 2–8, 13–18. It is reported that plasma type PAF‐AH has a higher molecular weight than the intracellular type and is resistant to protease 13.…”

Section: Discussionmentioning

confidence: 95%

“…The enzyme is distributed widely in tissues and plasma and is thought to be a defense mechanism that protects the host against the toxic effects of PAF and other biologically active oxidized phospholipids. Higher levels of PAF‐AH have been found in plasma and other body fluids in a variety of different diseases,2–8 but few studies have been conducted to measure the level of PAF‐AH in cerebrospinal fluid (CSF) 7. We, therefore, measured the PAF‐AH level in CSF of children with a variety of conditions, including meningitis, to determine if it is involved in the central nervous system (CNS) defense mechanism against the injury.…”

mentioning

confidence: 99%

Platelet‐activating factor acetylhydrolase activity in cerebrospinal fluid of children with acute systemic or neurological illness

Chang

Kwon

Kim

et al. 2002

Annals of Neurology

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Platelet-activating factor acetylhydrolase was analyzed in cerebrospinal fluid samples taken from children with a variety of neurological conditions (85 patients; mean age, 3.8 years) to determine it is involved in the defense mechanism against the toxic effect of inflammatory mediators in the central nervous system. A significant increase in cerebrospinal fluid activity was seen in the patients with meningitis and acute febrile illness in comparison with the control subjects. The activity was also significantly higher in the patients with meningitis than in the patients with inflammatory neurological diseases. In addition, the biochemical profile of cerebrospinal fluid platelet-activating factor acetylhydrolase was different from other known acetylhydrolases. These findings suggest that cerebrospinal fluid platelet-activating factor acetylhydrolase activity may be a sensitive marker of the host response to central nervous system infections.

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Detection and characterization of 45 kDa platelet activating factor acetylhydrolase in cerebrospinal fluid of children with meningitis

et al. 2003

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Platelet activating factor acetylhydrolase (PAF-AH) activity has been identified in cerebrospinal fluid (CSF) samples taken from children with meningitis. We reported that PAF-AH activity is significantly increased, by about 3 fold, in patients with meningitis compared to control subjects. Because of limited knowledge about this enzyme in CSF, we examined the biochemical properties of CSF PAF-AH. PAF-AH of CSF was calcium independent, showed a broad pH spectrum and was relatively heat stable. In addition, this enzyme activity was strongly inhibited by phenylmethanesulfonyl fluoride (PMSF), partially inhibited by p-bromophenacylbromide (p-BPB), uninhibited by iodoacetamide, and moderately stimulated by dithiothreitol (DTT). PAF-AH of CSF did not degrade phospholipid with a long chain fatty acyl group at sn-2 position. This enzyme hydrolyzed PAF and oxidatively modified phosphatidylcholine. Furthermore, we identified a monomeric polypeptide with a molecular weight of approximately 45 kDa by Western blot using human plasma PAF-AH antibody. These results suggested that plasma type PAF-AH activity exist in CSF taken from children with meningitis.

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The Presence of Platelet-Activating Factor-Acetylhydrolase in Human Middle Ear Effusions

Cited by 5 publications

References 17 publications

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

Platelet‐activating factor acetylhydrolase activity in cerebrospinal fluid of children with acute systemic or neurological illness

Detection and characterization of 45 kDa platelet activating factor acetylhydrolase in cerebrospinal fluid of children with meningitis

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