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Middle Ear Mucosa (middle + ear_mucosa)
Selected AbstractsGrowth Factors and Their Receptors in the Middle Ear Mucosa During Otitis Media,THE LARYNGOSCOPE, Issue 3 2002Sean D. Palacios MD Abstract Objective The hyperplastic response of the middle ear mucosa during bacterial otitis media is thought to be mediated by the actions of growth factors and their respective receptors. The purpose of the study was to explore the expression of growth factors known to stimulate epithelial cells in other systems, as well as their receptors, in the middle ear mucosa during otitis media. Study Design Expression of mRNA growth factors and receptors was measured over time after inoculation of the rat middle ear with bacteria. Methods The middle ears of 12 male Sprague-Dawley rats were injected with 105/mL Haemophilus influenzae strain 3655 (nontypeable, biotype II). Three rats were killed at 6, 24, 48, and 72 hours. Three untreated rats were also killed to serve as negative controls. The middle ear mucosa samples were surgically removed and homogenized. Reverse transcription-polymerase chain reaction was performed on each sample with primers for rat epidermal growth factor, epidermal growth factor receptor (ErbB), heparin binding epidermal-like growth factor, hepatocyte growth factor, hepatocyte growth factor receptor, keratinocyte growth factor, betacellulin, amphiregulin, and neuregulin-,. Results Hepatocyte growth factor and epidermal growth factor receptor primers demonstrated polymerase chain reaction products of the expected size that were not displayed in the normal middle ear mucosa. Keratinocyte growth factor and hepatocyte growth factor receptor demonstrated polymerase chain reaction products at all time points tested. Betacellulin and neuregulin-, products were present at all time points except 72 hours after infection. Conclusions The results of the study support a role for growth factors in the middle ear mucosa during otitis media. These bioactive ingredients contribute to mucosal hyperplasia. [source] Simultaneous intravenous and intramiddle-ear dosing to determine cefditoren influx and efflux clearances in middle ear fluid in freely moving chinchillasJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2003Tong Zhu Abstract This study was conducted to determine cefditoren (CDTR) transport kinetics between plasma and middle ear fluid (MEF) by characterizing influx (CLin) and efflux (CLout) clearances expressed in terms of unbound concentrations and their ratio. Simultaneous intravenous bolus and intramiddle-ear dose were administered to two groups of chinchillas: normal control and infected. In vivo microdialysis was employed to determine protein-unbound CDTR levels in MEF. Compartmental and noncompartmental analysis was performed. Parameters determined in both groups were compared to assess the effect of infection and inflammation on CDTR distribution kinetics. CLin and CLout estimates obtained by compartmental and noncompartmental analysis agreed well. The calculated CLin/CLout ratio was 0.76,±,0.23 and 0.56,±,0.25 in normal (n,=,9) and infected (n,=,6) animals, respectively. The 95% confidence interval of this ratio in both groups does not include unity. Statistical tests showed no difference (p,>,0.05) in CLin, CLout, and their ratio between the two groups. In conclusion, middle ear infection and inflammation does not affect CDTR distribution. The CLin/CLout ratio determined in chinchillas compares well with values estimated from data in pediatric patients. An active efflux mechanism in middle ear mucosa may be involved in CDTR distribution in MEF. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:1947,1956, 2003 [source] Effect of Inhibitor of Tumor Necrosis Factor-, and Oxatomide on Immune Mediated Otitis MediaTHE LARYNGOSCOPE, Issue 9 2006Yong-Soo Park MD Abstract Objective: Inflammatory mediators (IMs) play a major role in the production of middle ear effusion (MEE). Tumor necrosis factor (TNF)-, and leukotrienes (LTs) appear to be important in the pathogenesis of otitis media with effusion (OME). The purpose of this study is to determine the effect of TNF-, and LT antagonist on the outcome of experimental immune-mediated OME. Study Design: Prospective. Methods: Otitis media was induced in rats by injecting keyhole limpet hemocyanin (KLH) transtympanically 7 days after systemic immunization. Experimental groups were treated with soluble TNF receptor type I (sTNF RI) or oxatomide simultaneously. Seventy-two hours after transtympanic injection, MEE was aspirated, and temporal bone was taken. Vascular permeability (VP) of the middle ear mucosa was measured using the Evans blue dye technique. Hematoxylin-eosin stain and immunohistochemical stain for leukocyte common antigen was performed. Results: In KLH, sTNF RI, and oxatomide groups, MEE was developed in 83%, 0%, and 66% of the ears, respectively. The sTNF RI group showed significant decrease in effusion production, inflammation, mucosal thickening, and VP compared with the KLH group. These parameters were less significant in the oxatomide group than in the sTNF RI group. Conclusion: Transtympanic administration of sTNF RI and oxatomide appears to suppress the development of immune-mediated MEE. [source] Determination of Reactive Oxygen Species in Myringotomized Tympanic Membranes: Effect of Vitamin E TreatmentTHE LARYNGOSCOPE, Issue 4 2004Senol Polat MD Abstract Objectives/Hypothesis Recent studies have established a strong relationship between the development of myringosclerosis and reactive oxygen species (ROS). The aims of the present study were to directly detect ROS in the tympanic membrane and middle ear mucosa of rats by measuring luminol amplified chemiluminescence, to evaluate the changes in the levels of ROS after treatment with vitamin E, and to examine the possible changes in the tympanic membranes otomicroscopically and histologically. Study Design Prospective controlled animal study. Methods Forty healthy Sprague-Dawley rats were divided into five groups of eight animals each. Animals in all groups except group 1 were bilaterally myringotomized. Group 2 received no treatment, group 3 was treated with topical olive oil, group 4 received topical vitamin E, and group 5 received intramuscular vitamin E. After 24 hours of myringotomy, tympanic membranes were examined otomicroscopically; thereafter, tympanic membranes and middle ear mucosa were peeled off. The right ears of the animals were used for biochemical assay, and the left ears were used for histological study. Results Reactive oxygen species levels were significantly decreased in group 4 with topical application of vitamin E compared with untreated and myringotomized animals in group 2. Reactive oxygen species levels were also decreased in group 5, although the decrease was not statistically significant when compared with groups 2 and 3. Histological studies confirmed sclerotic changes in the untreated myringotomized animals. The tympanic membranes of animals in groups 2 and 3 showed a white, chalk-like pattern of sclerotic changes, whereas animals in groups 4 and 5, with the exception of two animals in group 5, lacked these changes. Conclusion Although the relationship between the development of myringosclerosis and ROS had been well documented previously, the present study is the first that has directly measured the levels of ROS in the tympanic membrane and middle ear mucosa. These results are relevant because they correlate with histological findings. It has also been demonstrated that topically applied vitamin E is effective in decreasing the ROS levels. [source] Growth Factors and Their Receptors in the Middle Ear Mucosa During Otitis Media,THE LARYNGOSCOPE, Issue 3 2002Sean D. Palacios MD Abstract Objective The hyperplastic response of the middle ear mucosa during bacterial otitis media is thought to be mediated by the actions of growth factors and their respective receptors. The purpose of the study was to explore the expression of growth factors known to stimulate epithelial cells in other systems, as well as their receptors, in the middle ear mucosa during otitis media. Study Design Expression of mRNA growth factors and receptors was measured over time after inoculation of the rat middle ear with bacteria. Methods The middle ears of 12 male Sprague-Dawley rats were injected with 105/mL Haemophilus influenzae strain 3655 (nontypeable, biotype II). Three rats were killed at 6, 24, 48, and 72 hours. Three untreated rats were also killed to serve as negative controls. The middle ear mucosa samples were surgically removed and homogenized. Reverse transcription-polymerase chain reaction was performed on each sample with primers for rat epidermal growth factor, epidermal growth factor receptor (ErbB), heparin binding epidermal-like growth factor, hepatocyte growth factor, hepatocyte growth factor receptor, keratinocyte growth factor, betacellulin, amphiregulin, and neuregulin-,. Results Hepatocyte growth factor and epidermal growth factor receptor primers demonstrated polymerase chain reaction products of the expected size that were not displayed in the normal middle ear mucosa. Keratinocyte growth factor and hepatocyte growth factor receptor demonstrated polymerase chain reaction products at all time points tested. Betacellulin and neuregulin-, products were present at all time points except 72 hours after infection. Conclusions The results of the study support a role for growth factors in the middle ear mucosa during otitis media. These bioactive ingredients contribute to mucosal hyperplasia. [source] Identification of MUC5B Mucin Gene in Human Middle Ear With Chronic Otitis Media,THE LARYNGOSCOPE, Issue 4 2000Hirokazu Kawano MD Objectives To identify the mucin gene and its expressing cells in the middle ear mucosa with chronic otitis media (COM), and to study the correlation between infiltration of inflammatory cells in the submucosa and expression of the mucin gene in the mucosal epithelium with COM. Study Design Middle ear mucosal specimens removed from the inferior promontory area of 19 patients undergoing middle ear surgery for COM were studied. Methods Sections were stained with H&E, Alcian blue-periodic acid Schiff (AB-PAS), polyclonal MUC5B antibody, and specific MUC5B riboprobe for histological, histochemical, immunohistochemical, and mucin mRNA analyses. Results H&E staining revealed pseudostratified epithelia in 18 of the middle ear specimens with COM and cuboidal secretory epithelia in one. AB-PAS staining of epithelia revealed abundant secretory cells and their products (glycoconjugates). In situ hybridization and immunohistochemistry studies demonstrated that the secretory cells of the middle ear mucosa with COM expressed MUC5B mucin mRNA and its product MUC5B mucin. Conclusions The MUC5B mucin gene and its product were identified in the middle ear secretory cells of patients with COM. Its e-pression was e-tensive in pseudostratified mucosal epithelia and related to infiltration of inflammatory cells in the submucosa of the middle ear cleft with COM, suggestive that inflammatory cell products are involved in the production of MUC5B. [source] Eosinophils are activated in middle ear mucosa and middle ear effusion of patients with intractable otitis media associated with bronchial asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2001Y. Iino Background Although patients with intractable otitis media associated with bronchial asthma have extensive accumulation of eosinophils in the middle ear mucosa and middle ear effusion, systematic histological and immunohistochemical studies have not been performed. Objectives To clarify the pathogenesis of middle ear diseases, we carried out immunohistochemical studies on middle ear specimens, particularly focusing on the characteristics of accumulated eosinophils. Methods Middle ear specimens obtained from eight adult patients and from 17 controls were immunohistochemically stained using monoclonal antibodies against EG1, EG2, mast cell tryptase, IgA and IgE. The concentration of eosinophil cationic protein (ECP) in middle ear effusion samples was also measured. Results In the asthmatic patients, severe round-cell infiltration was observed in the submucosa and most of the EG1-positive cells were also EG2-positive. In the control patients, the mucosa showed a fibrotic change with a few inflammatory cells, and EG1- or EG2-positive cells were quite few. The expression of IgE was found not only on the surface of mast cells but also within the plasma cells in the asthmatic patients, and the number of IgE-positive cells was about twice as high as that of mast cells. A significantly higher concentration of ECP was noted in middle ear effusion obtained from the asthmatic patients than that from the control patients. Conclusion Most of the eosinophils in the middle ear mucosa and middle ear effusion were activated, resulting in degranulation and release of ECP, and local IgE production occurs in the middle ear mucosa, indicating that the intractable inflammation is closely associated with IgE-mediated late phase response with eosinophil accumulation. [source] Topical Application of Calcium Channel Blockers to Reduce the Progression of Experimentally Induced Myringosclerosis and TympanosclerosisTHE LARYNGOSCOPE, Issue 4 2008Adin Selcuk MD Abstract Objectives: This study aimed to evaluate the ability of topically applied calcium channel blockers (diltiazem) to reduce the progression of experimentally induced myringosclerosis and tympanosclerosis. Study Design: Animal model. Experimental prospective study. Methods: The study included 25 adult albino guinea pigs that were bilaterally myringotomized and inoculated with a suspension of Streptococcus pneumonia type 3. The right ears were treated with topical application of diltiazem, and the untreated left ears served as the control group. Otomicroscopy and remyringotomy were conducted every week. One animal was sacrificed after 1 week and the remaining at the end of 6 weeks. Temporal bones were dissected, and tympanic bullae were analyzed with light microscopy. Results: The untreated control ears showed evidence of extensive myringosclerosis on otomicroscopy, and the ears treated with calcium channel blockers did as well although to a lesser degree. Under light microscopy, the lamina propria of both tympanic membranes and middle ear mucosae of the control group exhibited thicker (P < .1 and P < .05, respectively) and larger (P < .01 and P < .01, respectively) sclerotic tissue in comparison with the treatment group. Conclusion: The results suggest that calcium channel blockers had an influence in the prevention of tympanosclerosis. [source] | ||||||||||