Managing otitis externa.
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Administration, Topical↗
Biomedical subjects
John P Birchall
Publications and source records attributed to John P Birchall.
Evidence of T-helper cell 2 cytokine regulation of chronic otitis media with effusion.
Cytokine and cellular patterns of effusions may reflect stages of middle ear inflammation. The local interplay between IL-2 and -4 is likely to play a crucial role in the switching of inflammation in the chronic stage. The T-helper cell 2 (Th2) cytokines IL-4, -5 and -13 and the Th2/Th1 cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) regulate the cellular and molecular processes of chronic inflammation in the middle ear and therefore the chronic condition of otitis media with effusion (OME). Early identification of the cytokine and cellular patterns of effusions can be helpful in directing the clinical treatment of OME.We hypothesized that IL-2 and the group of Th2 cytokines regulate chronic inflammation in the middle ear and chronic OME. Effusions from children with persistent OME were analysed to determine the presence of cytokines (the Th1 cytokine IL-2, the Th2 cytokines IL-4, -5 and -13 and the Th1/Th2 cytokine GM-CSF), inflammatory cells (CD4+ T cells, eosinophils, macrophages and neutrophils) and mucin. Cytokines were evaluated by means of a quantitative "sandwich"-type ELISA, inflammatory cells by means of alkaline phosphatase-anti-alkaline phosphatase immunocytostaining and mucin by means of a modified periodic acid-Schiff method based on a slot-blot technique. The cytokine pattern in effusions varied from patient to patient. GM-CSF correlated positively and IL-4 inversely with IL-2 and the increased level of IL-4 may have had an inhibitory effect on IL-2. IL-5 and -13 correlated with IL-4. Inflammatory cells correlated with cytokines as follows: CD4+ T cells with IL-2 and -4; macrophages and neutrophils with GM-CSF; and eosinophils with IL-5. Some cytokine-cellular correlations in effusions were reflected at the clinical level. The mucin content of effusions correlated with the concentrations of IL-4 (>10 pg/ml) and -13, suggesting involvement of IL-4 and -13 in upregulation of the middle ear mucin metabolism.
CD4-Positive T-Lymphocytes↗
The immunoregulatory and allergy-associated cytokines in the aetiology of the otitis media with effusion.
Inflammation in the middle ear mucosa, which can be provoked by different primary factors such as bacterial and viral infection, local allergic reactions and reflux, is the crucial event in the pathogenesis of otitis media with effusion (OME). Unresolved acute inflammatory responses or defective immunoregulation of middle inflammation can promote chronic inflammatory processes and stimulate the chronic condition of OME. Cytokines are the central molecular regulators of middle ear inflammation and can switch the acute phase of inflammation in the chronic stage and induce molecular-pathological processes leading to the histopathological changes accompanying OME. In this review we present cytokines identified in otitis media, immunoregulatory [interleukin (IL)-2, IL-10, transforming growth factor-beta]) and allergy associated (IL-4, IL-5, granulocyte-macrophage colony-stimulating factor), as crucial molecular regulators, responsible for chronic inflammation in the middle ear and the chronic condition of OME.
Chronic Disease↗
LPS up-regulates mucin and cytokine mRNA expression and stimulates mucin and cytokine secretion in goblet cells.
Bacterial inflammation in mucosa is accompanied by morphological and proliferative changes in goblet cells and mucin hypersecretion. Main stimulators of bacterial inflammation are bacterial lipopolysaccharides (LPS). In vitro investigation of the LPS effect on the molecular processes in goblet cells, using the human mucin-secreting goblet cell line HT29-MTX, showed the following results. LPS up-regulated mucin and cytokine mRNA expression and secretion in goblet cells in a concentration and time-dependent manner, with a maximum output at an LPS concentration of 100 ng/ml. LPS (100 ng/ml) increased mRNA expression of MUC5AC (2.4x), MUC5B (2.1x), and IL-8 (2.3x) and stimulated secretion of mucins (MUC5AC up to 39%, MUC5B up to 31%) and the inflammatory cytokine IL-8 (up to 10x). A significant correlation was found between the LPS-induced IL-8 secretion and secretion of mucins. These results suggest: (1) goblet cells, responding to the direct stimulation of bacterial LPS by two inflammatory-related processes such as production and secretion of the gel-forming mucins and the inflammatory cytokine IL-8, can be considered as an important part of mucosal immunity and (2) LPS- induced goblet cell mucin secretion can occur partly via IL-8-dependent pathway.
Cell Line↗
Postural stability of preoperative acoustic neuroma patients assessed by sway magnetometry: are they unsteady?
OBJECTIVE: The objective was to evaluate the preoperative postural stability of acoustic neuroma patients using sway magnetometry. STUDY DESIGN: Prospective two-center study. METHODS: Fifty-one patients (mean age, 53 years) diagnosed with unilateral acoustic neuroma on magnetic resonance imaging at two tertiary referral centers were studied. Preoperatively, each patient had sway patterns (with eyes open and with eyes closed, and standing on foam) recorded for 120 seconds by sway magnetometry. Path length for 30 seconds was calculated. The Romberg coefficient (path length with eyes open divided by path length with eyes closed) was calculated. RESULTS: Forty-four percent of patients had abnormal path lengths with eyes open, and 49% with eyes closed. The Romberg coefficients were significantly lower than normal (P <.001; 95% CI, 0.19-0.87). Mean Romberg coefficient was 0.59 (normal value = 0.73), and all patients had a coefficient of less than 1. CONCLUSIONS: Half of preoperative acoustic neuroma patients are unsteady, exhibiting abnormal sway patterns based on path length measurements. The increase in sway path length demonstrable in normal subjects with eyes closed was significantly exaggerated in patients with acoustic neuroma.
Adolescent↗
Reflux of gastric juice and glue ear in children.
Otitis media with effusion (glue ear) is the most frequent cause of deafness in children. We investigated the role of gastric juice reflux in this disease. We measured pepsin concentrations in middle ear effusions from children using ELISA and enzyme activity assays. 45 (83%) of 54 effusions contained pepsin/pepsinogen at concentrations of up to 1000-fold greater than those in serum. Our data suggest that reflux of gastric juice could be a major cause of glue ear in children.
Child↗
In vitro study of IL-8 and goblet cells: possible role of IL-8 in the aetiology of otitis media with effusion.
One of the main characteristics of otitis media with effusion (OME) is the differentiation of basal cells into goblet cells with subsequent proliferation in a modified respiratory epithelium leading to the formation of mucin-rich effusion in the middle ear cleft. In order to determine the effect of pro-inflammatory cytokines identified in OME, e.g. IL-1beta, tumour necrosis factor (TNF)-alpha, IL-6 and IL-8, on goblet cells, and to clarify the role of IL-8 in particular, we used the human goblet cell line HT29-MTX, which secretes two OME-related mucins: MUC5AC and MUC5B. IL-1beta and TNF-alpha stimulated the secretion of IL-8 in HT29-MTX goblet cells. Dose- (2-200 ng/ml) and time- (0-5 days) response studies of IL-8-induced mucin secretion were carried out. IL-8 upregulated the secretion of MUC5AC and MUC5B mucins in a concentration-dependent manner, with a maximum response at an IL-8 concentration of 20 ng/ml. IL-8 (20 ng/ml)-mediated mucin secretion persisted for up to 5 days, with a peak response 72 h after the addition of cytokine. These results suggest that: (i) goblet cells are target cells for the pro-inflammatory cytokines IL-1beta, TNF-alpha and IL-8 and can contribute to the pathogenesis of OME by increasing both the concentration of IL-8 and the secretion of mucin; and (ii) IL-8 stimulates prolonged mucin secretion from goblet cells and may be involved in the maintenance of the disease in the chronic stage.
Cell Differentiation↗
Is gastric reflux a cause of otitis media with effusion in children?
OBJECTIVES/HYPOTHESIS: Otitis media with effusion is the most common cause of childhood deafness. Gastroesophageal reflux has been implicated in the disease pathogenesis; therefore, it is necessary to identify the presence or absence of gastric juice in the middle ear. STUDY DESIGN: Middle ear effusions were collected from children undergoing myringotomy. If gastric reflux has occurred, effusions should contain pepsin protein. METHODS: Total pepsin/pepsinogen protein, fibrinogen, and albumin content of effusions were measured in enzyme-linked immunosorbent assays using antibodies to porcine pepsin, human albumin, and human fibrinogen. Proteolytic activity of each effusion was measured at pH 2. The pH of effusions was measured. RESULTS: Fifty-nine of 65 effusion samples gave a positive result with the antipepsin antibody, which also recognized pepsinogen. Pepsin/pepsinogen levels ranged from 0.8 to 213.9 microg/mL (serum reference levels, 49.8-86.6 ng/mL). All effusions contained albumin and fibrinogen with respective ranges of 1.77 to 95.75 and 0.30 to 2.30 mg/mL (serum reference levels, 35-45 and 2.2 to 4.6 mg/mL, respectively). Acidic protease activity occurred in 19 of 65 effusion samples. The pH of effusion samples was 7 to 9. CONCLUSIONS: The majority of effusion samples contained pepsin/pepsinogen protein; only 29% were active. The pepsin level in effusion samples based on activity is substantially lower than levels based on antibody detection; however, the pH present would irreversibly inhibit pepsin, which would explain the low levels of active enzyme. Pepsin/pepsinogen levels in the effusion samples were up to 1000 times higher than serum levels, whereas albumin and fibrinogen levels were of the same magnitude. The pepsin in middle ear effusions is almost certainly due to reflux of gastric contents, and there may be a role for antireflux therapy in the treatment of otitis media with effusion.
Albumins↗
Role of the pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 and interleukin-8 in the pathogenesis of the otitis media with effusion.
Inflammation in the middle ear mucosa, caused usually by bacterial and viral pathogens, is the primary event in the middle ear predisposing the development of otitis media with effusion (OME). Numerous inflammatory mediators have been identified in OME. However, cytokines play a central role as initiators, mediators and regulators of middle ear inflammation and subsequent molecular-pathological processes in middle ear tissues, leading to histopathological changes in the middle ear cavity and the pathogenesis of OME. In this article, we aim to present an overview of current research developments in the pro-inflammatory cytokine involvement in the aetiology of otitis media with effusion.
Humans↗