Immunological studies of adenoids in children : Relation to atopy

The nasopharyngeal tonsil or adenoids is in constant interaction with our environment with every breath we take. This organ, rich in B cells, contains all the immunocompetent cells necessary for an interaction with T cells, exerted through secretion of cytokines and resulting in the production of immunoglobulins and the formation of memory cells. As part of Waldeyer's pharyngeal ring and of the mucosa-associated lymphoid tissue it plays an important role as a source of B cells for other parts of the upper respiratory tract. Adenoids act as a site for the induction of local and distant antibody responses in the defense against airway pathogens. The precise role and function of adenoids in the interactions between its own lymphoid cells and inhaled allergens is, however, poorly understood. Very little is known about the relationship between adenoid tissue and atopic diseases, and the local source of immunoglobulin (Ig)E- producing cells in the respiratory tract has been debated and is largely unknown. AIMS: The present work was performed with the ambition to increase our knowledge about the immunological functions of adenoid tissue in children, and put this in relation to atopy by investigating: - if the presence of atopy influences the microenviroment of adenoids with respect to cellular and other immunological findings. - if there are age-related differences in lymphocyte subpopulations in adenoids that support the hypothesis that this organ is involved in the development of immunological memory. - if differences observed in the context of atopy are in agreement with current knowledge regarding the immunology of atopic reactions. - if there is evidence of the adenoid tissue being involved in the development of IgE-mediated reactions, with IgE production taking place in adenoids. MATERIALS AND METHODS: Adenoids were surgically removed (adenoidectomy) from atopic and non-atopic children with adenoidal hyperplasia or otitis media with effusion. Children were classified as atopic if they had a positive PhadiatopR. OBS Flow cytometry and immunohistochemical methods were used to investigate lymphoid cell populations and subpopulations, transcripts of the cytokines IL-4 and IFN-gamma, epsilon germ line (epsilonGL) transcripts, secretion of the cytokines IL-2, IL-4 and IFN-gamma after non-specific stimulation, presence of IgE+ cells and IgE+ plasma cells. Peripheral blood lymphoid cell populations and subpopulations were also examined and related to the same populations in adenoids. RESULTS AND CONCLUSIONS: In all the studies performed, cellular and other immunological findings indicate a relationship between adenoid tissue and atopy. An increased occurrence of IgE+ cells and IgE+ plasma cells was found in adenoids of atopic compared to non- atopic children. epsilonGL transcripts were found to be dependent on IL-4 mRNA expression and serum IgE levels. Stimulation of adenoid cell cultures from atopic children resulted in a greater increase in B cells, increased activation of T cells and enhanced production of IL-4 but not IFN- gamma, compared to non-atopic children. The observation that memory T cell subsets in adenoids and blood are related to age indicates a role of adenoid tissue in the development of immunological memory. Besides linking atopy to the immunological function of adenoids, our results support the hypothesis that the adenoid tissue is involved in the development of IgE-mediated reactions and indicate that IgE production takes place locally in adenoids

High-frequency hearing, tinnitus, and patient satisfaction with stapedotomy : A randomized prospective study

Otosclerosis is a common disorder that leads to conductive hearing loss. Most patients with otosclerosis also have tinnitus, and surgical treatment is known to improve hearing as well as tinnitus. Some patients however experience worsening of tinnitus after the operation, but there are no known factors that allow surgeons to predict who will be at risk. In this prospective observational study on 133 patients undergoing stapedotomy, we show that postoperative air conduction thresholds at very high stimulus frequencies predict improvement of tinnitus, as assessed with proportional odds logistic regression models. Young patients were significantly more likely to experience reduction of tinnitus and patients whose tinnitus became better were also more satisfied with the outcome of the operation. These findings have practical importance for patients and their surgeons. Young patients can be advised that surgery is likely to be beneficial for their tinnitus, but a less positive message should be conveyed to older patients

Multitrophic interactions between insect herbivores and soil microbial communities

Over the last two decades strong evidence has emerged that. interactions between .soil microbes, plants and higher trophic levels can translate into functional changes which affect ecosystem functioning and productivity. One of the most intensively studied soil microbial groups are the arbuscular mycorrhizal fungi that have been demonstrated not only to affect the performance of plants, but also to interact with insect herbivores via the common host. Howeyer, the ecological significance of such interactions on above- and belowground processes often remain~ obscure, since most previous studies were conducted under the . exclusion ofnon-mycorrhizal soil organisms. In order to study mycorrhiza-insect herbivore interactions under ecologically more realistic conditions, the large majority of experiments presented in this thesis were carried out with naturally co-occurring soil microbial communities. Chapter three of this thesis describes experiments in which I examined the effects of insect shoot herbivory on mycorrhizal colonisation and on the community structure of mycorrhizal fungi. Chapter four describes experiments in which I studied the combined effects of insect root herbivory and mycorrhizal fungi on aboveground insect attack. In chapter five I investigated, whether plant-soil feedbacks affect mycorrhizal colonisation, plant chemistry and aboveground insect attack. Furthermore, I tested whether insect herbivore-induced changes. in soil microbial communities affect the performance of a new generation of plants and insect herbivores. The results from these experiments suggest (1) that insect shoot herbivores have less impact on arbuscular mycorrhizal fungi than insect root herbivores, (2) that the outcome of mycorrhiza-insect interactions largely depends on the plant species identity involved, (3) that insect-indu~d changes in non-mycorrhizal soil microbial communities might be an important mechanism eA'Plaining the productivity and composition of plant communities as well as the abundance of insect herbivores and (4) that interactions between mycorrhizal fungi and insect herbivores might sometimes be of low ecological relevance.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

(Upper graph) Change in hearing thresholds 6 weeks after surgery (as compared to measurements before the operation).

<p>Hearing was measured at the same set of frequencies as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115657#pone.0115657.g002" target="_blank">Fig. 2</a>. The size of each dot corresponds to the number of patients, obtained from the histogram for each frequency (5 dB bins) and boxes enclose the 95% confidence interval. Horizontal lines show the mean value at each frequency. One patient with complete sensorineural hearing loss after surgery is omitted from the plot (but included in all statistical analyses). <b>(Lower graph)</b>. Change in bone-conduction thresholds at 6 weeks. The scaling of the dots is the same in both panels.</p

(Upper graph).

<p>Change in hearing thresholds one year after surgery (as compared to measurements obtained before the operation). The size of each dot corresponds to the number of patients (obtained from the histogram for each frequency; 5 dB bins). Boxes enclose the 95% confidence interval and the horizontal lines give the mean at each frequency. One patient with complete sensorineural hearing loss after surgery is omitted from the plot. (<b>Lower graph</b>). Change in bone-conduction thresholds at 1 year. Dot scaling is identical in both graphs.</p

Consort flow diagram.

<p>A common reason for declining trial participation was that long travel distances made patients unwilling to return to the hospital for the 1-year follow-up visit. Otosclerosis is a clinical diagnosis, and 4 patients were found at surgery to have middle ear disorders where stapedotomy is not indicated. One patient in the placebo group was excluded in violation of the protocol because of a fracture of the stapes footplate. A total of 5 patients never received the study drug because their operations were postponed after study drugs had been delivered to the ward (but before drug infusion started).</p

Changes in scores for tinnitus, dizziness, and other variables.

<p>N.S. denotes not significant; OLR, ordered logistic regression.</p><p>* = p < 0.05</p><p>6. Positive changes denote improvement on the 10-grade scale used in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115657#pone.0115657.t001" target="_blank">Table 1</a>.</p><p>7. Patients graded the outcome on a 10-grade scale where 10 corresponded to a very good outcome and 0 to a very poor one.</p><p>8. The air-bone gap is the average difference between air conduction thresholds and bone conduction ones at the frequencies 0.5, 1, 2, and 3 kHz. Data are means ± 95% CI.</p><p>Changes in scores for tinnitus, dizziness, and other variables.</p

Demographic characteristics, hearing, and surgical factors in study patients.

<p>N.S. denotes not significant.</p><p>* denotes P<0.05.</p><p>1. Measured with a standard 50-item phonemically balanced word list</p><p>2 Measured with a 10-grade scale where 10 represent the best possible hearing quality. Numbers are medians and ranges.</p><p>3. Measured with a 10-grade scale where 10 represents very disturbing tinnitus or dizziness. Numbers are medians and ranges.</p><p>4 As reported by the surgeon performing the operation.</p><p>5 Reported by physician after examining the patient on the evening after the operation.</p><p>Demographic characteristics, hearing, and surgical factors in study patients.</p