Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interleukin-8 induces chemotaxis of neutrophils, basophils and T-lymphocytes, releases intracellular enzymes from neutrophils and histamine from basophils, and regulates the adhesion of neutrophils. In this study, using an enzyme-linked immunosorbent assay, we evaluated 33 middle ear effusions (MEEs) for levels of IL-8. The mean level of IL-8 in MEEs from children with OME was 616.7 +/- 211.0 pg/mgTP, while that of adults was 197.4 +/- 66.7 pg/mgTP. With respect to MEE types, the mean level of IL-8 in serous effusion was lower than that in two other types of MEEs (mucoserous and serous). These results suggest that inflammatory reaction in the middle ear cavity of children with OME is different from that of adults and that the pathogenesis of OME in children may differ from that in adults. Determination of IL-8 concentration in MEEs may help to illuminate the pathogenesis of OME.
 ...
PMID:Interleukin-8 in otitis media with effusion. 797 12

Streptococcus pneumoniae cell wall and pneumolysin are important contributors to pneumococcal pathogenicity in some animal models. To further explore these factors in middle ear inflammation caused by pneumococci, penicillin-induced inflammatory acceleration was studied by using three closely related pneumococcal strains: a wild-type 3 strain (WT3), its pneumolysin-negative derivative (P-1), and into autolysin-negative derivative (A-1). Both middle ears of chinchillas were inoculated with one of the three pneumococcal strains. During the first 12 h, all three strains grew in vivo at the same rate, and all three strains induced similar inflammatory cell responses in middle ear fluid (MEF). Procaine penicillin G was given as 12 h to one-half of the animals in each group, and all treated chinchillas had sterile MEF at 24 h. Penicillin significantly accelerated MEF inflammatory cell influx into WT3-and P-1-infected ears at 18 and 24 h in comparison with the rate for penicillin-treated A-1-infected ears. Inflammatory cell influx was slightly, but not significantly, greater after treatment of WT3 infection than after treatment of P-1 infection. Interleukin (IL)-1beta and IL-6, but not IL-8, concentrations in MEF at 24 h reflected the penicillin effect on MEF inflammatory cells; however, differences between treatment groups were not significant. Results suggest that pneumococcal otitis media pathogenesis is triggered principally by the inflammatory effects of intact and lytic cell wall products in the middle ear, with at most a modes additional pneumolysin effect. Investigation strategies that limit the release of these products or neutralize them warrant further investigation.
 ...
PMID:Roles of autolysin and pneumolysin in middle ear inflammation caused by a type 3 Streptococcus pneumoniae strain in the chinchilla otitis media model. 860 70

The importance of interleukin (IL)-8 in the chemotactic activity of middle ear effusions (MEEs) was evaluated. There was a significantly higher IL-8 concentration in MEEs of children with acute otitis media (AOM) (n = 17; 136 ng/mL) than in children with otitis media with effusion (OME) (n = 28; 65 ng/mL). The IL-8 concentration in MEEs with bacteria (149 ng/mL) was significantly higher than in MEEs without bacteria (66 ng/mL). MEEs from children with AOM and OME had equally higher chemotactic activity than the diluent alone (23.3% and 24.8% vs. 9.2%). The chemotactic activity was not altered by the presence of bacteria nor did it correlate with IL-8 concentration. Fractionation of MEEs by gel chromatography demonstrated that the main chemotactic activity could clearly be separated from the IL-8 activity, thus excluding IL-8 as a main chemotactic component in MEEs.
 ...
PMID:Interleukin-8 and chemotactic activity of middle ear effusions. 920 77

Interleukin-8 (IL-8), a potent neutrophilic chemoattractant and inflammatory cytokine, is present in middle ear effusions (MEEs) of children with otitis media and is thought to be responsible for the accumulation of neutrophils in MEEs. We hypothesized that IL-8 concentration predicts the total number and proportion of neutrophils in MEEs. IL-8 concentration and total and differential cell counts were measured in MEEs of children undergoing tympanostomy tube placement for otitis media. IL-8 was present in 80 (98%) of 82 effusions. The mean +/- SEM value for IL-8 was 7342 +/- 847 pg/mL. The mean +/- SEM count and percentage of neutrophils were 1.34 x 10(6) +/- 3.44 x 10(5) and 70.6 +/- 3.1%, respectively. IL-8 concentrations correlated positively with the total number (r = +0.30; P = 0.02) and percentage of neutrophils (r = +0.32; P = 0.01) in the effusion. Additionally, purulent effusions had greater IL-8 concentrations (P = 0.003) and greater neutrophil count (P = 0.03) than mucoid or serous effusions. We conclude that IL-8 is consistently present in MEEs of children and IL-8 concentration predicts the total number and proportion of neutrophils. Furthermore, IL-8 concentration and the total number of neutrophils correlate positively with the type of effusion. These results support the hypothesis that IL-8 recruits neutrophils to the middle ear in MEEs.
 ...
PMID:Interleukin-8 concentration predicts the neutrophil count in middle ear effusion. 929 7

Interleukin-8 (IL-8), a potent inflammatory mediator that is thought to control leukocyte recruitment and activation during inflammatory reactions, has been implicated in a variety of inflammatory diseases. Recent studies in our laboratory have demonstrated the presence of IL-8 in chronically inflamed human middle ear effusions. These data have led us to hypothesize that IL-8 is responsible for the leukocyte recruitment seen in otitis media. Because the effect of IL-8 on the middle ear mucosa has not been investigated and therefore its role in middle ear inflammation is not known, we investigated the ability of IL-8 to directly induce inflammation in the murine middle ear. For these studies, ICR mice were used to test the hypothesis that IL-8 could directly induce inflammation in the middle ear. Murine middle ears received 8-mL transtympanic injections of human IL-8 (25 mg/mL) in saline, heat-killed Streptococcus pneumoniae (1 x 10(8)/mL), or normal saline. Temporal bones were removed at 1, 4, 8, 24, and 48 hours, decalcified, and processed for histologic examination. Noninjected murine temporal bones served as controls. Normal saline-injected ears demonstrated little to no change as compared with temporal bones from noninjected ears. IL-8-injected ears histologically demonstrated thickening of the epithelial layer and subepithelial space (SES), with inflammatory cell infiltration in the SES peaking at 4 to 8 hours and resolving by 48 hours. Bacteria-injected ears demonstrated findings similar to, although not as extensive as, those found in IL-8-injected ears (i.e., inflammatory reactions peaked at 8 to 24 hours and resolved by 72 hours). Our results demonstrate that IL-8 is a potent inducer of middle ear inflammation and support the concept that IL-8 may be one of the key cytokines responsible for the leukocyte accumulation and activation seen in otitis media.
 ...
PMID:Murine model of interleukin-8-induced otitis media. 933 21

Interleukin-8 possesses chemotactic-activating properties toward neutrophils, and may contribute to the pathogenesis of middle ear inflammation. GRO/CINC-1 is a rat chemokine with structural and functional homology to human interleukin-8, the induction and regulation of which in the middle ear cavity in vivo remains to be established. The production of GRO/CINC-1 in middle ear lavage and gene expression in the middle mucosa was investigated using topical inoculation with lipopolysaccharide (LPS) in the rat in vivo model. GRO/CINC-1 in middle ear lavage showed time- and dose-dependent production under LPS stimulation. The peak of the GRO/CINC-1 production was reached by 4 h after LPS 1 h exposure, whereas the level of production subsequently returned to the level without LPS stimulation at 8 h after LPS stimulation. The topical corticosteroid perfusion in the middle ear after LPS stimulation significantly reduced the production of GRO/CINC-1 in the middle ear cavity compared with that without corticosteroid. At the time of peak production, the expression of GRO/CINC-1 mRNA, evaluated using the polymerase chain reaction, was considerable in the middle ear mucosa. This investigation of the characteristics of interleukin-8-like cytokine in the middle ear cavity using a rat in vivo model has extended the functional concept of chemokines at the initial stage in otitis media.
 ...
PMID:In vivo induction and regulation of interleukin-8-like chemokine GRO/CINC-1 in rat middle ear. 934 69

The chemokine interleukin 8 (IL-8) was instilled into the round window niche of rats through a small perforation in the tympanic membrane in order to study its effect on inner ear function by electrophysiological and morphological techniques. The frequency-specific auditory brainstem response (ABR) was recorded at the frequencies 4, 8, 10, 12, 16 and 20 kHz just before and 1, 2, 5 and 14 days after instilling IL-8 to ascertain the hearing level during each interval. Morphological examination by light microscopy was performed during the same interval following the instillation of IL-8. On day 1, the rise in ABR threshold was within 5 dB SPL (non-significant elevation). However, a significant threshold elevation (above 5 dB SPL) occurred in high-frequency areas (16 and 20 kHz) on day 2, and in middle frequency areas (10 and 12 kHz) on day 5 with sensorineural hearing loss type intensity-latency curves. By day 14, the elevated thresholds had returned to pre-instillation levels. In the lowest areas (4 and 8 kHz), no significant threshold elevation was detected at any time during the observation period. By light microscopy, on day 1, clusters of inflammatory cells (predominantly neutrophils) were observed just outside the round window membrane (RWM), while only a few neutrophils were detected in the cochlea. These cells were still present outside the RWM on day 2. The neutrophils had disappeared by day 5 and only macrophages were present on the middle ear side of the RWM. However, throughout the observation period, the organ of Corti and stria vascularis appeared to be intact. These results suggest that IL-8 in the middle ear cavity is able to influence inner ear function.
 ...
PMID:Interleukin 8 can affect inner ear function. 964 4

Recent studies have demonstrated the presence of inflammatory cytokines such as IL-1 beta, TNF-alpha, IL-6, and IL-8 in the middle ear effusion (MEE) of patients with otitis media with effusion (OME). IL-1 beta is known to be produced from macrophages and monocytes in an early stage of inflammation by stimulation with microorganisms and endotoxins. Also, these studies have shown that endotoxins frequently are found in MEE and can induce OME in experimental animal model. These findings suggest that endotoxins in MEE cause a chain reaction of cytokines through IL-1 beta. However, the precise role of IL-1 beta in the pathogenesis of OME has not yet been clarified. In the present study, a murine model of OME was developed by intra-tympanic injection with endotoxin or recombinant mouse IL-1 beta (rIL-1 beta) and the effects of IL-1 beta on the production of MEE were investigated. OME was induced in specific pathogen-free male BALB/c mice by intra-tympanic inoculation with endotoxin purified from nontypeable Haemophilus influenzae or with rIL-1 beta. The presence of MEE in the subjects was observed through the ear drum under a microscope and samples of MEE were collected by aspiration and washing with phosphate-buffered saline. The concentrations of IL-1 beta in each sample of MEE were determined by ELISA and the histological changes were compared. The mice inoculated with endotoxin showed signs of the production of MEE and it was noted that the levels of IL-1 beta in MEE were significantly increased on day 3. Intra-tympanic inoculation with rIL-1 beta also produced MEE and these cytological findings of MEE as well as the histological findings of middle ear mucosa were similar to those found in the endotoxin-induced OME. Further, the influence of anti-IL-1 receptor antibodies on the production of OME was examined 3 days after intra-tympanic injection with anti-IL-1 receptor antibodies together with endotoxin or rIL-1 beta. The incidence of OME was lower in mice injected with anti-IL-1 receptor antibodies than that in mice injected with endotoxin or rIL-1 beta only. These findings suggest that IL-1 beta may play an important role in the pathogenesis of OME.
 ...
PMID:[The role of IL-1 beta in murine model of otitis media with effusion]. 979 75

Streptococcus pneumoniae is the most frequent microbe causing middle ear infection. The pathophysiology of pneumococcal otitis media has been characterized by measurement of local inflammatory mediators such as inflammatory cells, lysozyme, oxidative metabolic products, and inflammatory cytokines. The role of cytokines in bacterial infection has been elucidated with animal models, and interleukin (IL)-1beta, IL-6, and IL-8 and tumor necrosis factor alpha (TNF-alpha) are recognized as being important local mediators in acute inflammation. We characterized middle ear inflammatory responses in the chinchilla otitis media model after injecting a very small number of viable pneumococci into the middle ear, similar to the natural course of infection. Middle ear fluid (MEF) concentrations of IL-1beta, IL-6, IL-8, and TNF-alpha were measured by using anti-human cytokine enzyme-linked immunosorbent assay reagents. IL-1beta showed the earliest peak, at 6 h after inoculation, whereas IL-6, IL-8, and TNF-alpha concentrations were increasing 72 h after pneumococcal inoculation. IL-6, IL-8, and TNF-alpha but not IL-1beta concentrations correlated significantly with total inflammatory cell numbers in MEF, and all four cytokines correlated significantly with MEF neutrophil concentration. Several intercytokine correlations were significant. Cytokines, therefore, participate in the early middle ear inflammatory response to S. pneumoniae.
 ...
PMID:Middle ear fluid cytokine and inflammatory cell kinetics in the chinchilla otitis media model. 1008 40

Polymorphonuclear granulocytes, which provide a major defence against Streptococcus pneumoniae infections, are attracted to and activated by various cytokines. The aim of this study was to analyse the cytokine response of human peripheral blood mononuclear cells to stimulation with S. pneumoniae. Strains belonging to serogroups 4, 6, 14, 19 or 23, were isolated from nasopharynx, middle ear fluid, cerebrospinal fluid or blood. All strains induced a marked proliferative response of the peripheral blood mononuclear cells; the stimulatory index was 34+/-11. High levels of pro-inflammatory cytokines were induced, i.e. interleukin (IL)-1beta (53+/-25 ng/ml), IL-6 (347+/-41 ng/ml) and tumour necrosis factor (TNF)-alpha (15+/-4 ng/ml). Also, chemokines and immunoregulatory cytokines including IL-8 (215+/-224 ng/ml), IL-10 (122+/-60 pg/ml), IL-12 (1195+/-648 pg/ml), interferon (IFN)-gamma (18+/-4 ng/ml) and granulocyte macrophage colony-stimulating factor (135+/-80 pg/ml) were induced. Several of these cytokines can up-regulate phagocytosis and the killing of bacteria. Interestingly, strains isolated from middle ear fluid and blood elicited significantly fewer IL-8 and significantly more IL-12 and IL-10 than strains from nasopharynx. They also induced a stronger proliferative response. Our results indicate that pneumococci are potent inducers of cytokines, especially IL-12, favouring T-helper cell type 1 (Th1) responses.
 ...
PMID:Induction of phagocyte-stimulating and Th1-promoting cytokines by in vitro stimulation of human peripheral blood mononuclear cells with Streptococcus pneumoniae. 1021 69


1 2 3 4 Next >>