[Repetitio est mater studiorum-implementation of ENT cases in case-based e-learning]. / Repetitio est mater studiorum ­ Implementierung von HNO-Fällen in fallbasiertes E-Learning.

BACKGROUND: German university otorhinolaryngology has a need for digital teaching content. Case-based e­learning represents a digital teaching methodology. The data on student use of case-based e­learning in university teaching of ENT medicine are limited. OBJECTIVE: The aim of this work was to determine the extent to which voluntary case-based e­learning is used by otolaryngology students and what influence the quality of the e­learning has on motivation to use e­learning and on the interest in otolaryngology. MATERIALS AND METHODS: Fifteen voluntary e­learning cases were created based on the content of the ENT lecture in the winter semester 2022/2023. Subsequently, a descriptive evaluation of the usage statistics of the cases of 157 students was conducted. Likewise, an evaluation of the quality of the e­learning as well as the motivation to complete it and the interest in otorhinolaryngology was carried out using a voluntary questionnaire. RESULTS: Voluntary case-based e­learning was used to varying degrees by 66% of the students. The quality of e­learning correlated significantly with the motivation and the interest in otolaryngology. CONCLUSION: The teaching content of otorhinolaryngology can be implemented sufficiently in case-based e­learning and is characterized by satisfactory student acceptance. Integration should be accomplished in a high-quality manner to increase motivation and interest in otorhinolaryngology.

Aspergillus fumigatus-Specific T Cells in Patients with Chronic Rhinosinusitis.

INTRODUCTION: Aspergillus fumigatus belongs to the saprophytic fungi, and its spores form a significant part of the daily load of fungal spores inhaled as particles in aerosols. A. fumigatus is a possible T-cell activator. Its contribution to the pathogenesis of chronic rhinosinusitis (CRS) is controversially discussed. The aim of this study was to detect and characterize A. fumigatus-specific CD4+ and CD8+ T cells in patients with CRS with (CRSwNP) and without (CRSsNP) nasal polyps. METHODS: Tissue and blood samples were collected from patients who underwent paranasal sinus surgery due to CRSwNP or CRSsNP. Afterward, purified CD4+ and CD8+ cells were cultured together with antigen-presenting cells. A peptide mix derived from A. fumigatus antigen was added to the cultures. After 6 days, multicolor flow cytometry was performed, and proliferation was measured using the marker Ki-67. Cytokine secretion was quantified from the supernatant of the cell culture. RESULTS: Significant differences in the proliferation of nasal CD4+ T cells to A. fumigatus antigen were observed for cells from patients with CRSwNP in comparison to CRSsNP, while no differences were found between nasal and peripheral blood T cells. The activation of tissue-derived CD4+ T cells was associated with significantly higher concentrations of IL-4, IL-5, and IL-17a in the cell culture from patients with CRSwNP in comparison to CRSsNP and/or healthy controls. CONCLUSION: Our findings indicate that patients with CRSwNP harbor a higher proportion of A. fumigatus-reactive CD4+ T cells in the nasal mucosa than patients with CRSsNP. A. fumigatus-reactive CD4+ T cells of CRSwNP patients secreted TH2 cytokines and IL-17. Our findings suggest a role for A. fumigatus in the pathogenesis of CRSwNP and provide a rationale for targeted therapies.

Cultivation of Head and Neck Squamous Cell Carcinoma Cells with Wound Fluid Leads to Cisplatin Resistance via Epithelial-Mesenchymal Transition Induction.

Locoregional recurrence is a major reason for therapy failure after surgical resection of head and neck squamous cell carcinoma (HNSCC). The physiological process of postoperative wound healing could potentially support the proliferation of remaining tumor cells. The aim of this study was to evaluate the influence of wound fluid (WF) on the cell cycle distribution and a potential induction of epithelial-mesenchymal transition (EMT). To verify this hypothesis, we incubated FaDu and HLaC78 cells with postoperative WF from patients after neck dissection. Cell viability in dependence of WF concentration and cisplatin was measured by flow cytometry. Cell cycle analysis was performed by flow cytometry and EMT-marker expression by rtPCR. WF showed high concentrations of interleukin (IL)-6, IL-8, IL-10, CCL2, MCP-1, EGF, angiogenin, and leptin. The cultivation of tumor cells with WF resulted in a significant increase in cell proliferation without affecting the cell cycle. In addition, there was a significant enhancement of the mesenchymal markers Snail 2 and vimentin, while the expression of the epithelial marker E-cadherin was significantly decreased. After cisplatin treatment, tumor cells incubated with WF showed a significantly higher resistance compared with the control group. The effect of cisplatin-resistance was dependent on the WF concentration. In summary, proinflammatory cytokines are predominantly found in WF. Furthermore, the results suggest that EMT can be induced by WF, which could be a possible mechanism for cisplatin resistance.

Investigation of Cellular Function and DNA Integrity during 2D in vitro Culture of Human Salivary Gland Epithelial Cells.

In vitro culture of human salivary gland epithelial cells (SGEC) is still a challenge. A high quantity and quality of cells are needed for the cultivation of 3D matrices. Furthermore, it is known that DNA damage is supposed to be an important factor involved in carcinogenesis. This study investigates cellular function and DNA integrity of human SGEC during 3 passage steps in 2 groups (group 1: n = 10; group 2: n = 9). Cellular function was analyzed by immunofluorescence, transmission electron microscopy (TEM), and quantitative real-time polymerase chain reaction (qPCR). DNA integrity was tested via the comet assay. Immunohistochemistry and qPCR results showed stable α-amylase and pan-cytokeratin levels; TEM revealed functional cells; and no significant DNA damage could be detected in the comet assay during 3 culture steps. The study shows that not only at cellular but also at DNA level human SGEC can be safely quantified over 3 passages for preclinical tissue engineering without loss of differentiation and function.

[In vitro exposure of the shisha tobacco ingredient glycerol to human mucosa cells and lymphocytes]. / In vitro-Exposition des Shisha-Tabak-Bestandteils Glycerin an humanen Mukosazellen und Lymphozyten.

Shisha tobacco has a higher amount of glycerol than cigarette tobacco. Moreover, new legislation in Germany cancels the old limitation of humectants in shisha tobacco. Although higher amounts of glycerol in tobacco are expected, the knowledge of the toxicological profile of glycerol regarding human cells is incomplete. Aim of the study was to test glycerol for cytotoxic and genotoxic effects and to discuss the risk of humectants in shisha tobacco and the situation of German tobacco control.Lymphocytes and nasal mucosa cells of 10 patients were exposed to different glycerol levels (0.001 mol/l to 6.0 mol/l). Cytotoxic effects were examined by trypan blue exclusion test, genotoxic effects by comet assay and micronucleus test.The trypan blue exclusion test revealed significant cytotoxic effects on lymphocytes and nasal mucosa cells for glycerol concentrations of 1.0 mol/l and higher. In the comet assay a significant DNA damage could be shown for glycerol levels of 1.0 mol/l and higher. No significant micronucleus formation was monitored.While the geno- and cytotoxicity were seen in concentrations of glycerol clearly exceeding the concentrations in main stream smoke of shishas, genotoxicity is a stochastic risk occurring even at subtoxic levels. Furthermore, toxicity in lower levels could result from tobacco combustion or interactions with other smoke components. For an extensive evaluation of the risks of humectants in shisha tobacco further studies are needed. In addition, there is an enormous need for introducing further measures of tobacco control policy in Germany.

The Proinflammatory Potential of Nitrogen Dioxide and Its Influence on the House Dust Mite Allergen Der p 1.

Asthma and allergies are both major global health problems with an increasing prevalence, and environmental data implicate an influence of air pollutants on their development. The present study focuses on the influence of nitrogen dioxide (NO2) and the major allergen of the house dust mite Der p 1 on human nasal epithelial cells of nonallergic patients in vitro. Nasal epithelial mucosa samples of 11 donors were harvested during nasal air passage surgery and cultured as an air-liquid interface. Exposure to 0.1, 1 and 10 ppm NO2 or synthetic air as a control was performed for 1 h. Subsequently, the cells were exposed to Der p 1 for 24 h. The release of interleukin (IL)-6 and IL-8 was measured by ELISA, and the production of IL-6 mRNA and IL-8 mRNA was measured by RT-PCR. NO2 exposure resulted in a concentration-dependent release of IL-6, but not IL-8 release. The coexposure of 0.1 ppm NO2 and Der p 1, or 1 ppm NO2 and Der p 1 significantly increased both IL-6 and IL-8 release. Exposure to NO2, Der p 1, or their combination, did not significantly influence the production of IL-6 or IL-8 mRNA. In conclusion, NO2 increases the release of inflammatory cytokines in human nasal epithelial cells, especially in coexposure with Der p 1, as a mechanism of allergotoxicology.

[Modern management of chronic rhinosinusitis]. / Modernes Management der chronischen Rhinosinusitis.

Chronic rhinosinusitis is a common disease. Due to the significant reduction of the quality of life, possible serious complications and economic consequences, a sufficient therapy is essential. With the entry of biologics into the treatment of chronic rhinosinusitis, relevant innovations have emerged in recent years. This article is aimed at providing an up-to-date overview of the conservative and surgical treatment options for chronic rhinosinusitis.

Single-port laparoscopic cholecystectomy versus standard multiport laparoscopic cholecystectomy: a case-control study comparing the long-term quality of life and body image.

PURPOSE: To study the postoperative quality of life and body image of patients who underwent either single-port cholecystectomy (SPC) or standard multiport laparoscopic cholecystectomy (SMLC) in a long-term assessment. METHODS: Fifty patients who underwent SPC using the reusable X-Cone™ Laparoscopic Device were compared with a matched group (age, sex, body mass index) of 50 patients after SMLC. The health-related quality of life (HRQOL) and body image at 17 months postoperatively (median, range 9-23) was analysed by means of the Short-Form 12 Health Survey and the Body Image Questionnaire, respectively. RESULTS: Both patient groups had comparable baseline characteristics, clinical courses, and postoperative complication rates. SPC patients were significantly more satisfied with the cosmetic result of their scar at 17 months postoperatively, in comparison to SMLC patients (cosmetic scale: 22.6 ± 2.8 vs. 19.5 ± 3.7, p < 0.001). However, the HRQOL did not differ between the SPC and SMLC patients (physical component scale: 50.0 ± 8.9 vs. 48.8 ± 9.4, p = 0.48; mental component scale: 53.8 ± 6.5 vs. 51.3 ± 8.5, p = 0.10). CONCLUSION: Although the overall postoperative HRQOL was comparable, this study suggests that the cosmetic result of SPC after complete wound healing is superior to the standard multiport laparoscopic procedure.

Evaluation of the cytotoxic and genotoxic potential of printer toner particles in a 3D air-liquid interface, primary cell-based nasal tissue model.

Printer toner particles (TPs) are a common, potentially hazardous substance, with an unclear toxicological impact on the respiratory mucosa. Most of the airways surface is covered by a ciliated respiratory mucosa, therefore appropriate tissue models of the respiratory epithelium with a high in vivo correlation are necessary for in vitro evaluation of airborne pollutants toxicology and the impact on the functional integrity. The aim of this study is the evaluation of TPs toxicology in a human primary cell-based air-liquid-interface (ALI) model of respiratory mucosa. The TPs were analyzed and characterized by scanning electron microscopy, pyrolysis and X-ray fluorescence spectrometry. ALI models of 10 patients were created using the epithelial cells and fibroblasts derived from nasal mucosa samples. TPs were applied to the ALI models via a modified Vitrocell® cloud and submerged in the dosing 0.89 - 892.96 µg/ cm2. Particle exposure and intracellular distribution were evaluated by electron microscopy. The MTT assay and the comet assay were used to investigate cytotoxicity and genotoxicity, respectively. The used TPs showed an average particle size of 3 - 8 µm. Mainly carbon, hydrogen, silicon, nitrogen, tin, benzene and benzene derivates were detected as chemical ingredients. By histomorphology and electron microscopy we observed the development of a highly functional, pseudostratified epithelium with a continuous layer of cilia. Using electron microscopy, TPs could be detected on the cilia surface and also intracellularly. Cytotoxicity was detected from 9 µg/ cm2 and higher, but no genotoxicity after ALI and submerged exposure. The ALI with primary nasal cells represents a highly functional model of the respiratory epithelium in terms of histomorphology and mucociliary differentiation. The toxicological results indicate a weak TP-concentration-dependent cytotoxicity. AVAILABILITY OF DATA AND MATERIALS: The datasets used and analysed during the current study are available from the corresponding author on reasonable request.

Detection of Candida albicans-Specific CD4+ and CD8+ T Cells in the Blood and Nasal Mucosa of Patients with Chronic Rhinosinusitis.

Candida albicans is ubiquitously present, and colonization in the nose and oral cavity is common. In healthy patients, it usually does not act as a pathogen, but in some cases can cause diseases. The influence of C. albicans as a trigger of T cell activation on the pathogenesis of chronic rhinosinusitis (CRS) is controversial, and its exact role is not clear to date. The aim of the present study was to detect and characterize C. albicans-specific CD4+ and CD8+ T cells in patients with CRS, with and without nasal polyps. Tissue and blood samples were collected from patients suffering from chronic rhinosinusitis with (CRSwNP) and without nasal polyps (CRSsNP), and from healthy controls. A peptide pool derived from C. albicans antigen was added to tissue and blood samples. After 6 days, lymphocytes were analyzed by multicolor flow cytometry. Activation was assessed by the intracellular marker Ki-67, and the cytokine secretion was measured. Tissue CD8+ T cells of CRSsNP patients showed a significantly higher proportion of Ki-67+ cells after activation with C. albicans antigen compared to peripheral blood CD8+ T cells. Cytokine secretion in response to C. albicans antigen was similar for all study groups. In this study, C. albicans-specific CD4+ and CD8+ T cells were detected in peripheral blood and mucosal tissue in all study groups. In patients suffering from CRSsNP, C. albicans-specific CD8+ T cells were relatively enriched in the nasal mucosa, suggesting that they might play a role in the pathogenesis of CRSsNP.

Investigation of the Immune Modulatory Potential of Zinc Oxide Nanoparticles in Human Lymphocytes.

Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed.

DNA Stability, Regeneration Capacity, and Mucociliary Differentiation of Human Nasal Mucosa Cells in Tissue Systems.

For culture models of primary cells of the human nasal mucosa, monocultures with epithelial cells (ECs) are used as well as cocultures with ECs and fibroblasts (FBs). Well-differentiated models of the respiratory nasal epithelium can be used for ecogenotoxicological assessments, for experiments on host/pathogen interactions, or tissue engineering. However, long-term cultivation and repeated passaging may induce a loss of DNA integrity or cell functionality. The aim of this study was to evaluate these parameters in test systems created from primary nasal mucosa cells. Enzymatic and sequential cell isolation from nasal tissue was performed. EC monocultures and compartment-separated EC-FB cocultures were cultivated over three passages under air/liquid interface conditions. DNA stability and regenerative capacity at the DNA and chromosomal level as well as proliferation and cell differentiation were examined. Both methods showed equivalent levels of DNA stability and regenerative capacity over all passages. Sequential growth of the coculture provided higher cell purity, while enzymatic cell harvest was associated with FB contamination in EC culture. Mucociliary differentiation was verified with electron microscopy in both methods. Functionality measured by lipopolysaccharide stimulation of interleukins was constant over long-term cultivation. Our data confirm DNA stability in long-term cell cultivation as well as functional integrity in both culture methods. Sequential cell isolation should be favored over enzymatic isolation due to higher culture purity. Impact statement Cell culture models are frequently used for ecogenotoxicological assessments, for experiments on host/pathogen interactions, or tissue engineering. However, DNA stability and functional integrity after long-term cultivation in such tissue models have not been investigated, yet. This study is the first showing systematic and evident data on DNA damage and functional aspects in primary human cell culture models of nasal epithelium.

Influence of nasal polyp tissue on the differentiation and activation of T lymphocytes in a co-culture system.

T cell subpopulations in nasal polyps differ from peripheral lymphocytes in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). However, little is known about the modulatory influence of the inflamed nasal polyp epithelial cells on the phenotype of the T cells. The aim of the present study was to assess this interaction. Tissue and blood samples were collected from 16 patients undergoing paranasal sinus surgery. Polypoid tissue was cultured under air-liquid interface conditions. Subsequently, cluster of differentiation (CD)3/CD28 activated peripheral lymphocytes from the same patients were added. After 3 days lymphocytes were separated from co-culture and analyzed by multicolor flow cytometry. Additionally, cytokine expression of the polyp tissue was measured using a human T helper cell (TH)1/TH2/TH17 antibody array. Viability staining of CD3+ lymphocytes detected fewer apoptotic cells under co-culture conditions compared with in mono-culture. There was a significantly higher frequency of CD4+ and CD8+ T cells in the co-culture system than in PBMC culture alone. Human leukocyte antigen (HLA)-DR isotype was significantly downregulated on co-cultured CD3+ lymphocytes and CD3+CD4+ T cells compared with the mono-cultured counterparts. Conventional Forkhead box P3- memory CD4+ T cells and activated regulatory T cells increased in frequency, and resting regulatory T cells decreased in the co-culture. Cytokine analysis identified expression of interleukin (IL)-6, IL-6 receptor, granulocyte-macrophage colony-stimulating factor, transforming growth factor-ß and macrophage inflammatory protein-3 in the polyp tissue. In summary, the present study performed a comparison between peripheral lymphocytes cultured with and without nasal polyp tissue cells was performed. The downregulation of HLA and the differentiation of Treg and Tconv by nasal polypoid tissue on PBMCs was demonstrated. Interestingly, the in vivo downregulation of HLA-DR on CD3+ lymphocytes, as reported previously, was confirmed in vitro. The inhibitory effect of polypoid tissue on the activation of lymphocytes is a possible pathogenic mechanism underlying CRSwNP.

Wound fluid enhances cancer cell proliferation via activation of STAT3 signal pathway in vitro.

Wound healing begins immediately after surgery with a modification of the microenvironment via a well­orchestrated interaction between cells, cytokines and growth factors. Some of these growth factors and cytokines have mitogenic effects on cancer cells, which may lead to enhanced cancer cell proliferation and early metastatic events. The present study aimed to investigate the effects of wound fluid (WF) on the head and neck squamous carcinoma cell lines FaDu and HLaC78 in vitro. WF was harvested from 7 patients who had undergone a planned neck dissection. The presence of cytokines and growth factors was evaluated with the dot blot assay. Proliferation and cell viability were investigated via MTT assay and Ki-67 staining. Cell invasion was measured via tree­dimensional invasion assay. Western blotting was used to investigate STAT 3 activation. WF contained several cytokines and growth factors responsible for pro­ and anti­inflammation, chemotaxis, proliferation and angiogenesis. The proliferation effect of WF on FaDu and HLaC78 was concentration dependent. Media with 40% WF resulted in the highest proliferation effect. FaDu and HLaC78 exhibited enhanced motility after cultivation with 40% WF compared with cultivation with expansion medium. Cultivating cancer cells with WF had no advantageous effect on cell viability after the paclitaxel treatment. Western blot analysis revealed enhanced activation of the STAT3 signaling pathway by WF in both FaDu and HLaC78. In conclusion, surgery leads to excessive release of mitogenic factors. The contact of non­resected cancer cells and these factors may have a negative impact on patient outcome. Future investigations should specifically focus on the inhibition of mitogenic factors following cancer surgery in order to prevent early metastasis and cancer recurrence.

Impact and Modulations of Peripheral and Edaphic B Cell Subpopulations in Chronic Rhinosinusitis With Nasal Polyposis.

OBJECTIVES: The pathophysiological mechanisms of chronic rhinosinusitis with nasal polyposis (CRSwNP) still are discussed controversially. Regulatory B cells (Breg) are responsible for the suppression of T cell activity: deficiencies for Breg have been demonstrated to contribute to autoimmune disorders, e.g., systemic lupus erythematosus. In order to evaluate the influence of B cell subpopulations, especially Breg, on the etiology of this disease, the aim of this study was to characterize subpopulations of peripheral and edaphic B cells in CRSwNP. METHODS: Polypoid tissue and blood samples were collected from 10 patients undergoing paranasal sinus surgery and lymphocytes were analyzed by multicolor flow cytometry. RESULTS: There was a significantly lower frequency of B cells in nasal polyps compared to peripheral blood mononuclear cells (PBMC) in patients with CRSwNP. Mature resting B cells were the main population within B cells in PBMC, and memory B cells in nasal polyps. Remarkably, Breg and mature B cells significantly decreased in nasal polyps compared to PBMC. Memory B cells significantly increased and represented the main subpopulation in nasal polyps in patients with CRSwNP. CONCLUSION: In this study a detailed contemporary characterization of B cell subpopulations in patients with CRSwNP is presented. The influence of edaphic B cells could play a key role in the maintenance of this chronic infectious disease.

Toxicological characterization of ZnO nanoparticles in malignant and non-malignant cells.

The increasing usage of zinc oxide nanoparticles (ZnO-NPs) in industrial applications as well as in consumer products raises concern regarding their potential adverse effects to a greater extend. Numerous studies have demonstrated toxic properties of NPs, however there is still a lack of knowledge concerning the underlying mechanisms. This study was designed to systematically investigate cytotoxicity, apoptosis, cell cycle alterations, and genotoxicity induced by ZnO-NP. Moreover, it was an aim of the investigations to specify the diverse effects of nanoparticle exposure in malignant in comparison with non-malignant cells. Therefore, human head and neck squamous cell carcinoma-derived FaDu cells were incubated with 4-20 µg/ml of ZnO-NPs for 1-48 hr and tested for cell viability, cell cycle alterations, apoptosis and caspase-3 gene expression as a sensitive marker of molecular apoptotic processes with regard to time- and dose-dependent effects. Human mesenchymal bone marrow stem cells were used as non-malignant representatives to examine oxidative stress-related genotoxicity. Results showed a significant reduction in cell viability as well as dose- and time-dependent increase of apoptotic cells following nanoparticle treatment. Likewise, caspase-3 gene expression enhanced already before first apoptotic cells were detectable. It could be observed that doses that were cytotoxic in tumor cells did not reduce viability in stem cells. However, the same concentrations already induced significant DNA damage. The findings of the study suggest to keep a more critical eye on the use of nanoparticles as anti-cancer agents. Yet, additional in vivo studies are needed to assess safety concerns for consumers and patients. Environ. Mol. Mutagen. 59:247-259, 2018. © 2017 Wiley Periodicals, Inc.

Accumulation of CD69+ tissue­resident memory T cells in the nasal polyps of patients with chronic rhinosinusitis.

In patients with chronic rhinosinusitis with nasal polyps (CRSwNP), a relative accumulation of cluster of differentiation (CD)8+ T cells over CD4+ T cells occurs in nasal polyps compared with the peripheral blood. Nasal CD8+ T cells and CD4+ T cells predominantly present an effector memory phenotype. Immunological studies have reported that memory T cells recirculate from the tissues to the peripheral blood and a high percentage of these T cells persist within the tissue. The aim of the present study was to characterize CD69+ sphingosine­1­phosphate receptor 1 (S1PR1)­ tissue resident memory T cells (Trm) in the polyps of patients with CRSwNP. Tissue and blood samples were collected from 10 patients undergoing nasal sinus surgery. Expression of specific extra­ and intracellular molecules were analyzed using multicolor flow cytometry. A significantly higher level of CD8+ T cells than CD4+ T cells was present in nasal polyps, while significantly more CD4+ T cells than CD8+ T cells were detected in the peripheral blood of patients with CRSwNP. The frequency of CD69+ T cells was significantly higher in CD8+ and CD4+ T cells in nasal polyps compared with the peripheral blood. The frequency of CD69+ S1PR1­ Trm was also significantly higher in CD4+ and CD8+ T cells from nasal polyps compared with the peripheral blood. Within polyps, the frequency of CD69+ S1PR1­ Trm was again significantly higher in CD8+ compared with CD4+ T cells. In summary, a significantly higher frequency of CD69+ S1PR1­ T cells was observed in the nasal polyps compared with the peripheral blood in patients with CRSwNP. The results of the present study suggest that local regulation of the immune response occurs within nasal polyps. As such, Trm should be considered a potential stimulus in the pathogenesis of nasal polyps. However, the role of Trm in nasal polyps as a pathogenic trigger of the local inflammatory reaction requires further investigation.

Long-term changes in the properties of skin-derived fibroblasts following irradiation of the head and neck.

The tumor stroma performs an important role in carcinogenesis. It predominantly consists of fibroblasts and the connective tissue produced by them, and undergoes a multitude of interactions with the surrounding cancer cells. Since irradiation is part of the majority of therapeutic strategies for head and neck squamous cell carcinoma, more information regarding the effects of a previous irradiation on the tumor stroma is desirable. In the present study, fibroblasts were cultivated from human non-irradiated and pre-irradiated skin of the neck for 48 h. Subsequently, analyses of cell viability, apoptosis, necrosis and motility were conducted via MTT assay, Annexin V/propidium iodide staining, electronic cell counting for 4 consecutive days, and scratch assay. Pre-irradiated fibroblasts exhibited a significantly slower growth rate as well as increased rates of apoptosis and necrosis. They also exhibited significantly decreased motility compared with non-irradiated fibroblasts. These results indicated the long-term effects of irradiation on fibroblasts, which may affect cancer recurrence in the irradiated region via the tumor stroma. More information, such as that regarding the secretory capacities of pre-irradiated fibroblasts, is required to evaluate the possible therapeutic implications of these findings.

Characterization of T-cell subpopulations in patients with chronic rhinosinusitis with nasal polyposis.

BACKGROUND: There is an ongoing discussion concerning the potential origins of chronic rhinosinusitis with nasal polyposis (CRSwNP). OBJECTIVE: The aim of this study was to quantify subpopulations of T cells in peripheral blood and nasal polyps in CRSwNP to examine their influence on the etiology of this disease. METHODS: Tissue and blood samples were collected from 11 patients who underwent nasal sinus surgery, and these samples were analyzed by multicolor flow cytometry. RESULTS: There was a significantly lower frequency of CD4+ T-helper (Th) cells and a significantly higher frequency of CD8+ T cells among lymphocytes isolated from nasal polyps compared with peripheral blood mononuclear cells (PBMC). In both T-cell subpopulations, a shift mainly from naive T cells among peripheral blood lymphocytes toward an effector memory and terminally differentiated subtype predominance in nasal polyps was observed. Among CD4+ T cells, the frequencies of cluster of differentiation (CD) 45RA- Forkhead-Box-Protein P3high (FoxP3high) cytotoxic T-lymphocyte-associated Protein 4high (CTLA-4high) activated regulatory T (Treg) cells, and CD45RA- Forkhead-Box-Protein P3low (FoxP3low) memory T cells were significantly increased in nasal polyps compared with PBMC. CONCLUSION: In this study, we presented a detailed characterization of CD4+ and CD8+ T-cell subpopulations in patients with CRSwNP. CD8+ T cells were more prominent in nasal polyps than in CD4+ T cells. Both nasal CD8+ T cells and CD4+ T cells predominantly had an effector memory phenotype. Among CD4+ T cells, activated Treg cells were increased in nasal polyps compared with PBMC. The data point toward a local regulation of T-cell composition within the microenvironment of nasal polyps, which might be further exploited in the future to develop novel immunotherapeutic strategies.

Genotoxic effects of zinc oxide nanoparticles in nasal mucosa cells are antagonized by titanium dioxide nanoparticles.

Titanium dioxide nanoparticles (TiO2-NPs) and zinc oxide nanoparticles (ZnO-NPs) are often used in sunscreens and other consumer products due to their photoprotective properties. However, concern exists regarding them possibly causing cyto- and genotoxic effects. The aim of this study was to assess cyto- and genotoxicity of these nanomaterials after single or combined exposure. For this purpose, a battery of cell culture test systems for human nasal mucosa (monolayer, air-liquid interface and mini organ culture) were exposed to 0.1-20µg/ml of TiO2- and ZnO-NPs alone and in combination. Cytotoxicity was measured by the MTT assay, and DNA damage and repair capacity were investigated using the comet assay. TiO2-NPs did not exhibit any cyto- or genotoxic potential within the tested concentrations. However, results of the study indicated cyto- and genotoxicity resulting from ZnO-NPs. The genotoxicity could be antagonized by TiO2-NPs. Furthermore, the DNA repair capacity after ZnO-NP-induced DNA damage was enhanced by TiO2-NPs. The adsorption of dissolved zinc ions onto TiO2-NPs is discussed as the major antagonistic mechanism. The combination of both metal oxide nanoparticles interferes with the genotoxicity of ZnO-NPs and should be discussed as a reasonable and safe alternative to the sole use of ZnO-NPs in consumer products.