Characterization of epithelial cells, connective tissue cells and immune cells in human upper airway mucosa by immunofluorescence multichannel image cytometry: a pilot study.

Epithelial, connective tissue and immune cells contribute in various ways to the pathophysiology of chronic rhinosinusitis (CRS). However, data of their distribution in upper airway mucosa are sparse. We aimed to provide quantitative, purely informative data on the distribution of these cell lineages and their coexpression patterns, which might help identifying, e.g., cells in the epithelium undergoing through epithelial-mesenchymal transition (EMT). For this purpose, we used immunofluorescence multichannel image cytometry (IMIC). We examined fixed paraffin-embedded tissue samples (FFPE) of six patients with chronic rhinosinusitis (CRS) and of three patients without CRS (controls). The direct-conjugated antibodies pancytokeratin, vimentin and CD45/CD18 were used for coexpression analysis in epithelial layer and lamina propria. Image acquisition and analysis were performed with TissueFAXS and StrataQuest, respectively. To distinguish positive from negative expression, a ratio between cell-specific immunostaining intensity and background was developed. Isotype controls were used as negative controls. Per patient, a 4.5-mm2 tissue area was scanned and a median of 14,875 cells was recognized. The most common cell types were cytokeratin-single-positive (26%), vimentin-single-positive (13%) and CD45/CD18-single-positive with CD45/CD18-vimentin-double-positive cells (29%). In the patients with CRS, CD45/CD18-single-positive cells were 3-6 times higher compared to the control patients. In the epithelial layer, cytokeratin-vimentin-double-positive EMT cells were observed 3-5 times higher in the patients with CRS than in the control patients. This study provided quantitative data for the distribution of crucial cell types in CRS. Future studies may focus on the distribution and coexpression patterns of different immune cells in CRS or even cancer tissue.

[Biologics for Chronic Rhinosinusitis]. / Biologika bei chronischer Rhinosinusitis.

Chronic rhinosinusitis (CRS) is an inflammation of the nasal and paranasal mucosa, lasting for more than 12 weeks. By now approximately 15 % of the European and American population are affected, which indicates that CRS is a serious health problem. Beside other subgroups the most important classification is CRS with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP). Standard-of-care therapies include nasal saline solution as well as topic or systemic corticosteroids. If this does not lead to a sufficient recovery, surgical therapy is a good option. A new therapy option is represented by biologics, particularly monoclonal antibodies (mAB). They are well-established for treatment of asthma bronchiale. Due to the fact that asthma is often associated with nasal polyps, and mAB may could also lead to improvements in CRS, studies were conducted. In the meantime there is a number of mAB which have emerged as an alternative treatment for patients with CRSwNP.

Evaluation of transient-evoked otoacoustic emissions in a healthy 1 to 10 year pediatric cohort in Sub-Saharan Africa.

OBJECTIVE: Transient-evoked otoacoustic emissions (TEOAEs) monitor cochlear function. High pass rates have been reported for industrialized countries. Pass rates in low and middle income countries such as Sub-Saharan Africa are rare, essentially lower and available for children up to 4 years of age and frequently based on hospital recruitments. This study aims at providing additional TEOAE pass rates of a healthy Sub-Saharan cohort aged 1-10 years with data from Gabon, Ghana and Kenya. Potentially confounding factors (recruitment site, age) are taken into consideration. METHODS: Healthy children were recruited in hospitals, schools and kindergartens. Inclusion criteria were age 1-10 years and normal otoscopic findings. Exclusion criteria were any sickness or physical ailment potentially impairing the hearing capacity. Five measurements per ear were performed with Capella Cochlear Emission Analyzer (MADSEN, Germany). An overall wave reproducibility of above 60% served as pass-criterion. Pass rates were compared between recruitment sites and age groups (1-5 and 6-10 years). RESULTS: Overall pass rate was 87.5% (n = 264; 231 passes vs. 33 fails). Of these 84.0% of hospital recruited children passed (n = 156; 131 passes vs. 25 fails), compared to 92.6% of community recruitments (n = 108; 100 passes vs. 8 fails), which was significantly different p = 0.039). If analyzed by age groups, this difference was only observed in children younger than 6 years (p = 0.007). CONCLUSION: Hospitals as recruitment sites for healthy controls seem to affect TEOAE pass rates. We advise for a cautious approach when recruiting healthy TEOAE control collectives under the age of 6 in a hospital setting. In children older than 6 years conventional pure-tone audiometry remains the standard method for hearing screening.

Surviving murine experimental sepsis affects the function and morphology of the inner ear.

Severe sepsis is known to result in various neurological long-term deficits in human. Recently, a link between severe, lethal sepsis and significant hearing loss with correlating histomorphological inner ear changes in mice (C57BL/6) was observed. However, if similar observations can be made in severe, non-lethal sepsis in mice is unclear. This study evaluates mice after severe, non-lethal sepsis for analogue functional and histomorphological alterations of the inner ear.A total of 63 C57BL/6 mice were included in the study. All underwent an initial hearing test with auditory brainstem response on day 1. In 35 mice sepsis was induced by cecal ligation and puncture (CLP), in 15 sham surgery was performed and 13 served as healthy control. A second hearing test was performed on day 7. All mice were sacrificed afterwards for further histomorphological evaluation of the inner ears. Immunohistochemical analysis with apoptotic markers Cleaved-caspase 3, BAX and BCL-2 were performed to identify structural inner ear damage.Of all CLP mice, 21/35 (60.0%) died due to the induced sepsis. Of the surviving CLP mice, 14/35 (40.0%), post-treatment hearing thresholds differed significantly from the sham and control mice (P<0.001). Positive immunostaining at different inner ear structures, like the spiral ligament or the supporting cells could be observed. The percentage of the immunostained positive area in the spiral ligament significantly correlated with the grade of hearing loss for BAX (P=0.027) and Cleaved-caspase 3 (P=0.024) but not for BCL 2 (P>0.05).The present data suggests that severe, non-lethal sepsis in mice results in significantly elevated hearing thresholds. A positive labelling for the pro-apoptotic markers BAX and Cleaved-caspase 3 suggested the induction of apoptosis in inner ear.

Severe malaria in children leads to a significant impairment of transitory otoacoustic emissions--a prospective multicenter cohort study.

BACKGROUND: Severe malaria may influence inner ear function, although this possibility has not been examined prospectively. In a retrospective analysis, hearing impairment was found in 9 of 23 patients with cerebral malaria. An objective method to quickly evaluate the function of the inner ear are the otoacoustic emissions. Negative transient otoacoustic emissions are associated with a threshold shift of 20 dB and above. METHODS: This prospective multicenter study analyses otoacoustic emissions in patients with severe malaria up to the age of 10 years. In three study sites (Ghana, Gabon, Kenya) 144 patients with severe malaria and 108 control children were included. All malaria patients were treated with parental artesunate. RESULTS: In the control group, 92.6 % (n = 108, 95 % confidence interval 86.19-6.2 %) passed otoacoustic emission screening. In malaria patients, 58.5 % (n = 94, malaria vs controls p < 0.001, 95 % confidence interval 48.4-67.9 %) passed otoacoustic emission screening at the baseline measurement. The value increased to 65.2 % (n = 66, p < 0.001, 95 % confidence interval 53.1-75.5 %) at follow up 14-28 days after diagnosis of malaria. The study population was divided into severe non-cerebral malaria and severe malaria with neurological symptoms (cerebral malaria). Whereas otoacoustic emissions in severe malaria improved to a passing percentage of 72.9 % (n = 48, 95 % confidence interval 59-83.4 %) at follow-up, the patients with cerebral malaria showed a drop in the passing percentage to 33 % (n = 18) 3-7 days after diagnosis. This shows a significant impairment in the cerebral malaria group (p = 0.012 at days 3-7, 95 % confidence interval 16.3-56.3 %; p = 0.031 at day 14-28, 95 % confidence interval 24.5-66.3 %). CONCLUSION: The presented data show that 40 % of children have involvement of the inner ear early in severe malaria. In children, audiological screening after severe malaria infection is not currently recommended, but is worth investigating in larger studies.

The role of sensitivity to transients in the detection of appearing and disappearing objects in complex acoustic scenes.

We report a series of psychophysics experiments that investigated listeners' sensitivity to changes in complex acoustic scenes. Specifically, we sought to test the hypothesis that change detection is supported by sensitivity to change-related transients (an abrupt change in stimulus power within a certain frequency band, associated with the appearance or disappearance of a scene element). This hypothesis, in the context of natural scenes, is commonly dismissed on account that the elements of the scene may themselves be characterized by on-going energy fluctuations that would mask any genuine change-related transients. We created artificial 'scenes' populated by multiple pure-tone components. Tones were modulated (by a square wave at a distinct rate) so as to mimic the fluctuation properties of complex sounds. "Change" was defined as the appearance or disappearance of one such element. Importantly, such scenes lack semantic attributes, which may have been a limiting factor in interpreting previous auditory change-detection studies, thus allowing us to probe the low-level, pre-semantic, processes involved in auditory change perception. In Experiment 1 we measured listeners' ability to detect item appearance and disappearance in conditions where change-related transients are masked by a silent gap. In Experiment 2, we investigated the effect of an acoustic distractor - a brief signal that occurs at the time of change, but does not mask any scene components. The data show that gaps adversely affected the processing of item appearance but not disappearance. However, distractors reduced both -appearance and disappearance detection. Together our results suggest a role for sensitivity to transients in the process of auditory change detection, similar to what has been demonstrated for visual change detection.

Detection of appearing and disappearing objects in complex acoustic scenes.

The ability to detect sudden changes in the environment is critical for survival. Hearing is hypothesized to play a major role in this process by serving as an "early warning device," rapidly directing attention to new events. Here, we investigate listeners' sensitivity to changes in complex acoustic scenes-what makes certain events "pop-out" and grab attention while others remain unnoticed? We use artificial "scenes" populated by multiple pure-tone components, each with a unique frequency and amplitude modulation rate. Importantly, these scenes lack semantic attributes, which may have confounded previous studies, thus allowing us to probe low-level processes involved in auditory change perception. Our results reveal a striking difference between "appear" and "disappear" events. Listeners are remarkably tuned to object appearance: change detection and identification performance are at ceiling; response times are short, with little effect of scene-size, suggesting a pop-out process. In contrast, listeners have difficulty detecting disappearing objects, even in small scenes: performance rapidly deteriorates with growing scene-size; response times are slow, and even when change is detected, the changed component is rarely successfully identified. We also measured change detection performance when a noise or silent gap was inserted at the time of change or when the scene was interrupted by a distractor that occurred at the time of change but did not mask any scene elements. Gaps adversely affected the processing of item appearance but not disappearance. However, distractors reduced both appearance and disappearance detection. Together, our results suggest a role for neural adaptation and sensitivity to transients in the process of auditory change detection, similar to what has been demonstrated for visual change detection. Importantly, listeners consistently performed better for item addition (relative to deletion) across all scene interruptions used, suggesting a robust perceptual representation of item appearance.