Antibiotic treatment in acute Otitis Media promotes superinfection with resistant Streptococcus pneumoniae carried before initiation of treatment.
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Antibiotic-resistant pneumococci are difficult to eradicate from middle ear fluid (MEF) and the nasopharynx (NP). Bacteriologic eradication from the NP and MEF during acute otitis media (AOM) by 3 common antibiotic drugs was prospectively evaluated. In 19 (16%) of 119 MEF culture-positive patients, an organism susceptible to the treatment drug (Haemophilus influenzae, Streptococcus pneumoniae, or both) was isolated from the initial MEF, whereas resistant S. pneumoniae was present in the NP; in 9 (47%) patients, the initial resistant NP organism (identified by serotyping, resistance to the administered drug, and pulsed-field gel electrophoresis) replaced the susceptible MEF organism within only a few days after initiation of treatment. In regions where resistant pneumococci are prevalent, antibiotics may not only fail to eradicate the organisms, but they may often induce MEF superinfection with resistant pneumococci initially carried in the NP. This is an important mechanism by which, in recently treated patients, AOM infections often become refractory to treatment. (+info)
Malignant peripheral nerve sheath tumor in the parapharyngeal space: tumor spread through the eustachian tube.
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SUMMARY: We report the CT and MR findings in a patient with malignant peripheral nerve sheath tumor in the parapharyngeal space who had neither a family history nor stigmata of neurofibromatosis. A high-resolution CT scan of the temporal bone revealed bony erosion and widening of both the foramen ovale and the bony portion of the eustachian tube. A temporal bone MR image showed an intensely enhancing solid mass in the parapharyngeal space, which extended into the middle ear cavity via the eustachian tube. (+info)
Intranasal immunization enhances clearance of nontypeable Haemophilus influenzae and reduces stimulation of tumor necrosis factor alpha production in the murine model of otitis media.
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Nontypeable Haemophilus influenzae (NTHi) is a major pathogen causing otitis media (OM). One of the outer membrane proteins of NTHi, P6, is a common antigen to all strains and is considered a candidate for mucosal vaccine. We have previously reported that intranasal immunization with P6 and cholera toxin (CT) could induce P6-specific immunoglobulin A (IgA) antibodies in the middle ear. In the present study, we assessed the effect of intranasal immunization for the protection against NTHi-induced OM. Mice were immunized intranasally with P6 and CT as an adjuvant on days 0, 7, and 14. Control mice were given phosphate-buffered saline (PBS) without antigen. One week after the final immunization, a suspension of live NTHi (10(7) CFU) was injected into the tympanic cavity to induce experimental OM. On days 3 and 7 after bacterial challenge, mice were killed and middle ear effusions (MEEs) were collected. All immunized mice showed elevated titers of P6-specific antibodies in MEEs. The rank order of specific antibody included, from highest to lowest levels, IgG, IgA, and IgM. In addition, immunized mice showed enhanced clearance of NTHi from the middle ear and the number of NTHi in MEEs of immunized mice was reduced by 97% on day 3 and by 92% on day 7 after bacterial challenge relative the number in the MEEs of control mice. The protective effect of intranasal immunization on the incidence of NTHi-induced experimental OM was evident on day 7 after challenge. By day 7, the number of MEEs in immunized mice was 64% less than that in control mice and the incidence of NTHi culture-positive MEEs in immunized mice was 56% less than that in control mice. Less stimulation of tumor necrosis factor alpha (TNF-alpha) production in the middle ear was evident on day 3 after challenge. Immunized mice showed lower concentrations of TNF-alpha in MEEs. These results indicate that intranasal immunization affords protection against experimental OM as evidenced by enhanced clearance of NTHi and less stimulation of TNF-alpha production in the middle ear. These findings suggest that a nasal vaccine might be useful for preventing OM. (+info)
Expression of cytokine and chemokine genes by human middle ear epithelial cells induced by formalin-killed Haemophilus influenzae or its lipooligosaccharide htrB and rfaD mutants.
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To define the role of nontypeable Haemophilus influenzae (NTHI) lipooligosaccharide (LOS) in the induction of proinflammatory cytokine gene expression during otitis media, we compared the abilities of formalin-killed NTHI strain 2019 and its LOS htrB and rfaD mutants to stimulate human middle ear epithelial (HMEE) cell cytokine and chemokine gene expression and production in vitro. Strain DK-1, an rfaD gene mutant, expresses a truncated LOS consisting of only three deoxy-D-manno-octulosonic acid residues, a single heptose, and lipid A. Strain B29, an isogenic htrB mutant, possesses an altered oligosaccharide core and an altered lipid A. HMEE cells were incubated with formalin-killed NTHI 2019, B29, or DK-1. The supernatants and the cells were collected at 2, 4, 8, and 24 h after stimulation. Expression of genes for the cytokines tumor necrosis factor alpha (TNF-alpha), interleukin lbeta (IL-1beta), and IL-6 and for the chemokines macrophage inflammatory protein 1beta (MIP-1beta), monocyte chemotactic peptide 1 (MCP-1), and IL-8 was quantitated by real-time PCR. NTHI B29 did not significantly stimulate any cytokine or chemokine mRNA expression in HMEE cells. In striking contrast, NTHI 2019 induced up to 105-, 139-, and 187-fold increases in HMEE cell expression of IL-1beta, TNF-alpha, and MIP-1beta, respectively (P < 0.01 [2019 versus B29]). NTHI 2019 also induced upregulation of IL-8, IL-6, and MCP-1 mRNA expression (by 26-, 44-, and 14-fold, respectively [P < 0.05 (2019 versus B29)]). The significant induction of cytokine genes was confirmed by quantitating the secretion of cytokines in culture supernatants with an enzyme-linked immunosorbent assay. There were no significant differences in mRNA expression of IL-8, IL-6, and MCP-1 between the 2019- and DK-1-treated groups. The low levels of gene transcripts observed after incubation of HMEE cells with B29 indicate that products of the disrupted NTHI htrB LOS gene may play a major role in induction of these particular inflammatory mediators. (+info)
Characterization of mucins in human middle ear and Eustachian tube.
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Mucins are important glycoproteins in the mucociliary transport system of the middle ear and Eustachian tube. Little is known about mucin expression within this system under physiological and pathological conditions. This study demonstrated the expression of MUC5B, MUC5AC, MUC4, and MUC1 in the human Eustachian tube, whereas only MUC5B mucin expression was demonstrated in noninflamed middle ears. MUC5B and MUC4 mucin genes were upregulated 4.2- and 6-fold, respectively, in middle ears with chronic otitis media (COM) or mucoid otitis media (MOM). This upregulation of mucin genes was accompanied by an increase of MUC5B- and MUC4-producing cells in the middle ear mucosa. Electron microscopy of the secretions from COM and MOM showed the presence of chainlike polymeric mucin. These data indicate that the epithelium of the middle ear and Eustachian tube expresses distinct mucin profiles and that MUC5B and MUC4 mucins are highly produced and secreted in the diseased middle ear. These mucins may form thick mucous effusion in the middle ear cavity and compromise the function of the middle ear. (+info)
Improved outcome for patients with middle ear rhabdomyosarcoma: a children's oncology group study.
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PURPOSE: The goal of this study was to define the clinical features and optimal therapy for children and adolescents with middle ear (ME) rhabdomyosarcoma (RMS). PATIENTS AND METHODS: We reviewed demographic data, clinical features, therapy (including chemotherapy, surgery, and radiation), and outcome for the 179 eligible patients with ME RMS who were enrolled onto Intergroup Rhabdomyosarcoma Studies (IRS) I through IV or pilot studies between November 1972 and December 1997. RESULTS: Most patients were younger than 10 years old (90%), and 63% were male. Because of the parameningeal location, most tumors were not resected before chemotherapy (group I, < 1%; group II, 4%; group III, 84%; group IV, 12%). Although most tumors were locally invasive (T2, 89%), the majority were small (< or = 5 cm, 66%), lacked nodal metastases (N0, 86%), and had embryonal histology (85%). The 5-year failure-free survival (FFS) and overall survival (OS) estimates were 67% and 72%, respectively. Both FFS and OS improved significantly over the course of IRS I through IV (3-year FFS and OS: IRS-I, 42% and 42%; IRS-II, 70% and 74%; IRS-III, 65% and 72%; IRS-IV pilot, 81% and 96%; IRS-IV, 88% and 88%, P <.001). Lower clinical group or stage and smaller tumor size were associated with better outcome. Age, sex, tumor invasiveness, and nodal metastases were not predictive of outcome. CONCLUSION: Patients with ME RMS generally present with small, unresectable, invasive tumors at a site traditionally considered prognostically unfavorable. Nevertheless, such patients have benefited markedly from improvements in multimodal, risk-based therapy during the course of IRS I through IV, and with contemporary therapy, most are cured. (+info)
Postoperative complications in otospongiosis: usefulness of MR imaging.
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BACKGROUND AND PURPOSE: Sensorineural hearing loss (SNHL) is a rare complication of stapes surgery that may arise for many reasons. Usually, the pathogenesis of SNHL can be established by clinical and CT examinations. The purpose of this study was to evaluate the utility of MR imaging when CT findings are normal or not contributive. METHODS: Eleven patients with SNHL (in some instances, associated with vertigo) after stapedectomy, in whom CT showed no well-defined cause, were examined by MR imaging. RESULTS: MR studies established the additional findings of reparative intravestibular granuloma (n = 2), intralabyrinthine hemorrhage (n = 1), and bacterial labyrinthitis (n = 1). In five cases, MR findings were similar to CT findings. In two cases, CT and MR results were normal. Revision surgery was performed in five patients and confirmed the MR findings in each case. CONCLUSION: If CT is not contributive as to the origin of SNHL and vertigo occurring after stapes surgery, then MR imaging may be helpful in these patients. (+info)
Peripheral specialization for fine analysis of doppler-shifted echoes in the auditory system of the "CF-FM" bat Pteronotus parnellii.
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Pteronotus parnellii uses the second harmonic (61-62 kHz) of the CF component in its orientation sounds for Doppler-shift compensation. The bat's inner ear is mechanically specialized for fine analysis of sounds at about 61-62 kHz. Because of this specialization, cochlear microphonics (CM) evoked by 61-62 kHz tone bursts exhibit prominent transients, slow increase and decrease in amplitude at the onset and cessation of these stimuli. CM-responses to 60-61 kHz tone bursts show a prominent input-output non-linearity and transients. Accordingly, a summated response of primary auditory neurones (N1) appears not only at the onset of the stimuli, but also at the cessation. N1-off is sharply tuned at 60-61 kHz, while N1-on is tuned at 63-64 kHz, which is 2 kHz higher than the best frequency of the auditory system because of the envelope-distortion originating from sharp mechanical tuning. Single peripheral neurones sensitive to 61-62 kHz sounds have an unusually sharp tuning curve and show phase-locked responses to beats of up to 3 kHz. Information about the frequencies of Doppler-shifted echoes is thus coded by a set of sharply tuned neurones and also discharges phase-locked to beats. Neurones with a best frequency between 55 and 64 kHz show not only tonic on-responses but also off-responses which are apparently related to the mechanical off-transient occuring in the inner ear and not to a rebound from neural inhibition. (+info)