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.

[Microvascular reconstruction of the larynx following total laryngectomy]. / Mikrovaskuläre Kehlkopfrekonstruktion nach totaler Laryngektomie.

Total laryngectomy still is a standard procedure for the treatment of advanced laryngeal or hypopharyngeal carcinoma. The unavoidable loss of voice may lead to serious impairments in quality of life. The most common technique of voice restoration is the tracheal-esophageal puncture combined with the application of a voice prosthesis. Laryngeal reconstruction with a radial forearm flap represents a possible surgical method of voice restoration. This study is a mono-center retrospective analysis of patients receiving a so-called laryngoplasty after total laryngectomy between 2006 and 2015, focusing on long-term functional outcome and complications. 39 patients were included. Sufficient phonation was possible in 77 %, finger-free speaking was achieved in 62 %. Exclusion of irradiated patients revealed a rehabilitation rate of 91 %. The most common early complication was cervical hematoma in 15 %, whereas no loss of flap was assessed. Stenosis of the laryngoplasty was seen in 7 cases, mainly post-irradiation. The rate of successful voice restoration is equal in both, laryngoplasty and voice prosthesis patients. However, voice quality is better after surgical reconstruction. Complications induced by the voice prosthesis, which may be severe in some cases, were not seen in the study group. Furthermore, life-long support by an ENT specialist regarding voice prosthesis exchange is not necessary. Assuming correct choice of candidates, laryngoplasty is a sufficient method for voice restoration after laryngectomy.

[Mesenchymal stem cells: Cancer promoting effects or tumor suppression - A current overview]. / Mesenchymale Stammzellen: Tumorfördernde oder -hemmende Eigenschaften ­ Ein aktueller Überblick.

The multimodal treatment of cancer deals with cancer cells as well as with the cancer surrounding stroma. This stroma contains non-malignant cells like fibroblasts, immune cells as well as mesenchymal stem cells (MSC). MSC have the ability to migrate towards cancer tissue. In the current literature the impact of MSC on cancer cells is discussed divergently. The majority of the current publications reveal an induction of cancer progression by MSC. Four main processes namely the secretion of soluble factors and cell-cell contact, the transdifferentiation of MSC into carcinoma associated fibroblasts, the improvement of neoangiogenesis and the induction of immune suppression are responsible for cancer progression. This publication gives an overview on the current literature.

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.

Two-stage autotransplantation of human submandibular gland: a novel approach to treat postradiogenic xerostomia.

Xerostomia is a persistent side effect of radiotherapy (RT), which severely reduces the quality of life of the patients affected. Besides drug treatment and new irradiation strategies, surgical procedures aim for tissue protection of the submandibular gland. Using a new surgical approach, the submandibular gland was autotransplanted in 6 patients to the patient's forearm for the period of RT and reimplanted into the floor of the mouth 2-3 months after completion of RT. Saxon's test was performed during different time points to evaluate patient's saliva production. Furthermore patients had to answer EORTC QLQ-HN35 questionnaire and visual analog scale. Following this two-stage autotransplantation, xerostomia in the patients was markedly reduced due to improved saliva production of the reimplanted gland. Whether this promising novel approach is a reliable treatment option for RT patients in general should be evaluated in further studies.

Vascularization of engineered cartilage constructs in a mouse model.

Tissue engineering of cartilage tissue offers a promising method for reconstructing ear, nose, larynx and trachea defects. However, a lack of sufficient nutrient supply to cartilage constructs limits this procedure. Only a few animal models exist to vascularize the seeded scaffolds. In this study, polycaprolactone (PCL)-based polyurethane scaffolds are seeded with 1 × 10(6) human cartilage cells and implanted in the right hind leg of a nude mouse using an arteriovenous flow-through vessel loop for angiogenesis for the first 3 weeks. Equally seeded scaffolds but without access to a vessel loop served as controls. After 3 weeks, a transposition of the vascularized scaffolds into the groin of the nude mouse was performed. Constructs (verum and controls) were explanted 1 and 6 weeks after transposition. Constructs with implanted vessels were well vascularized. The amount of cells increased in vascularized constructs compared to the controls but at the same time noticeably less extracellular matrix was produced. This mouse model provides critical answers to important questions concerning the vascularization of engineered tissue, which offers a viable option for repairing defects, especially when the desired amount of autologous cartilage or other tissues is not available and the nutritive situation at the implantation site is poor.

Chromosomal aberrations and deoxyribonucleic acid single-strand breaks in adipose-derived stem cells during long-term expansion in vitro.

BACKGROUND AIMS: Adipose-derived stem cells (ASCs) are a promising mesenchymal cell source for tissue engineering approaches. To obtain an adequate cell amount, in vitro expansion of the cells may be required in some cases. To monitor potential contraindications for therapeutic applications in humans, DNA strand breaks and chromosomal aberrations in ASCs during in vitro expansion were examined. METHODS: After isolation of ASC from human lipoaspirates of seven patients, in vitro expansion over 10 passages was performed. Cells from passages 1, 2, 3, 5 and 10 were used for the alkaline single-cell microgel electrophoresis (comet) assay to detect DNA single-strand breaks and alkali labile as well as incomplete excision repair sites. Chromosomal changes were examined by means of the chromosomal aberration test. RESULTS: During in vitro expansion, ASC showed no DNA single-strand breaks in the comet assay. With the chromosomal aberration test, however, a significant increase in chromosomal aberrations were detected. CONCLUSIONS: The study showed that although no DNA fragmentation could be determined, the safety of ASC cannot be ensured with respect to chromosome stability during in vitro expansion. Thus, reliable analyses for detecting ASC populations, which accumulate chromosomal aberrations or even undergo malignant transformation during extensive in vitro expansion, must be implemented as part of the safety evaluation of these cells for stem cell-based therapy.

Assessment of nicotine-induced DNA damage in a genotoxicological test battery.

The role of the tobacco-alkaloid nicotine in tumour biology is widely discussed in the literature. Due to a strong capacity to induce angiogenesis, a pro-mutagenic potential in non-tumour and cancer cells, and a pro- and anti-apoptotic influence, nicotine seems to promote the growth of established tumours. However, results indicating DNA damage and genetic instability associated with nicotine have been contradictory thus far. A variety of markers and endpoints of genotoxicity are required to characterize the genotoxic potential of nicotine. Induction of DNA single- and double-strand breaks, the formation of micronuclei, and the induction of sister chromatid exchange and chromosome aberrations represent possible genotoxicological endpoints at different cellular levels. Human lymphocytes were exposed to nicotine concentrations between 1µM and 1mM for 24h in vitro. The comet assay, the cytokinesis-block micronucleus test, the chromosome aberration (CA) test, and the sister chromatid exchange (SCE) test were then applied. Viability and apoptosis were measured by flow cytometry in combination with the annexin V-propidium iodide staining test. In this test setting, no enhanced DNA migration was measured by the comet assay. An increase in the micronucleus frequency was detected at a concentration of 100µM nicotine without affecting the frequency of apoptotic cells. A distinct genotoxic effect was determined by the CA test and the SCE test, with a significant increase in CA and SCE at a concentration of 1µM. In the annexin V test, nicotine did not influence the proportion of apoptotic or necrotic cells. The current data indicating the induction of CA by nicotine underscore the necessity of ongoing investigations on the potential of nicotine to initiate mutagenesis and tumour promotion. Taking into account the physiological nicotine plasma levels in smokers or in nicotine-replacement therapy, particularly the long-term use of nicotine should be critically discussed.

Nitrogen dioxide is genotoxic in urban concentrations.

In the discussion on toxic and genotoxic thresholds of air pollutants such as nitrogen dioxide (NO2), realistically low urban concentration ranges are of major interest. For NO2, the WHO defines the annual limit value as corresponding to 0.02 ppm. In the present study, the toxicity and genotoxicity of NO2 is set at a concentration under this limit value and examined in human nasal epithelium at different exposure durations in vitro. Nasal epithelial mucosa samples of 10 donors were harvested during nasal air passage surgery and cultured as an air-liquid interface. Exposure to 0.01 ppm NO2 or synthetic air as a control was performed for 0.5, 1, 2 and 3 h. Analysis included the caspase-3 ELISA, the single cell microgel electrophoresis (comet) assay and the micronucleus assay. The caspase-3 activity was not influenced by NO2 exposure, DNA strand fragmentation correlated with exposure durations to NO2 at 0.01 ppm NO2, and no cytotoxic effects such as apoptosis, necrosis or disturbances of cell proliferation were present. However, micronucleus induction as a sign of genotoxicity at an exposure duration of 3 h could be shown. Shorter exposures did not induce micronucleus formation. In summary, genotoxicity of NO2 could be demonstrated at a common urban concentration in vitro, but a threshold of NO2 genotoxicity could not be defined based on the present experiments.

Bone marrow carcinosis in head and neck carcinoma in a young adult.

Bone marrow carcinosis has been reported as a consequence of several solid tumors. However, in relation to head and neck squamous cell carcinoma, it is an indication of the rarity of the disease that only 2 reported cases exist in the literature. A 36-year-old male patient was admitted with the diagnosis of squamous cell carcinoma on the floor of the mouth. After the exclusion of distant metastatic disease, tumor surgery was performed. After a regular postoperative course over 3 days, the patient complained of progressive pain in the lower back. Extensive workup included position-emission tomography, which detected an enhancement of the bone marrow. Bone marrow biopsy elucidated advanced bone marrow carcinosis. Palliative chemotherapy was recommended, but the patient deteriorated rapidly and died from septic multiorgan failure within 6 weeks after surgery. Thus, bone marrow carcinosis must be considered in patients with head and neck tumor and osseous pain.

Decellularized porcine derived membrane (Tarsys®) for correction of lower eyelid retraction.

Retraction of the lower eyelid can be consequence of medical and surgical conditions. Various kinds of allotransplants and biomaterial have been used to correct it; we report on the surgical correction of lower lid retraction with a decellularized porcine derived membrane (Tarsys(®)). A 49-year-old patient with a history of adenoid cystic carcinoma in the pterygo-palatine fossa, requiring extensive surgery and repeated radiotherapy, presented with 6 mm lagophthalmus and exposure keratopathy secondary to facial nerve palsy. The lower lid malposition was corrected with a Tarsys(®) implant. Three months after surgery no lagophthalmos was present and substantial relief of signs and symptoms of ocular surface disease and good symmetry between right and left eye was achieved. If general condition or morbidity in potential donor sites hamper harvesting autologous graft material to support the lower lid, bioengineered xenografts can be used successfully to correct eyelid malpositions such as lower lid retraction.

Head and neck squamous cancer cells enhance the differentiation of human mesenchymal stem cells to adipogenic and osteogenic linages in vitro.

Human mesenchymal stem cells (hMSC) are multipotent cells with the ability to differentiate into a range of different cell types, including fat, bone, cartilage or muscle. A pro-tumorigenic effect of hMSC has been previously reported as part of the tumor stroma. In addition, studies have previously revealed the influence of hematopoietic and lymphoid tumors on hMSC differentiation to support their own growth. However, this possible phenomenon has not been explored in solid malignancies. Therefore, the aim of the present study was to investigate the effects of head and neck squamous cell carcinoma (HNSCC) lines Cal27 and HLaC78 on the induction of osteogenic and adipogenic differentiation in hMSCs. Native hMSCs were co-cultured with Cal27 and HLaC78 cells for 3 weeks. Subsequently, hMSC differentiation was assessed using reverse transcription-PCR and using Oil Red O and von Kossa staining. Furthermore, the effects of differentiated hMSCs on Cal27 and HLaC78 were examined. For this purpose, hMSCs differentiated into the adipogenic (adipo-hMSC) and osteogenic (osteo-hMSC) lineages were co-cultured with Cal27 and HLaC78. Cell viability, cytokine secretion and activation of STAT3 signaling were measured by cell counting, dot blot assay (42 cytokines with focus on IL-6) and western blotting (STAT3, phosphorylated STAT3, ß-actin), respectively. Co-culturing hMSCs with Cal27 and HLaC78 cells resulted in both adipogenic and osteogenic differentiation. In addition, the viability of Cal27 and HLaC78 cells was found to be increased after co-cultivation with adipo-hMSCs, compared with that of cells co-cultured with osteo-hMSC. According to western blotting results, Cal27 cells incubated with adipo-hMSCs exhibited increased STAT3 activation, compared with that in cells co-cultured with native hMSCs and osteo-hMSCs. IL-6 concentration in the media of Cal27 and HLaC78 after co-cultivation with respectively incubation with conditioned media of hMSCs, adipo-hMSCs and osteo-hMSCs were also found to be increased compared with that in the media of Cal27 and HLaC78 cells incubated with DMEM. To conclude, HNSCC cell lines Cal27 and HLaC78 induced hMSC differentiation towards the adipogenic and osteogenic lineages in vitro. Furthermore, a proliferative effect of adipo-hMSCs on Cal27 and HLaC78 cells was revealed with STAT3 activation as a possible mechanism. These results warrant further investigation of the interaction between HNSCC cells and hMSCs, with focus on the mechanism underlying the differentiation of hMSCs.

Adipose tissue-derived stem cells show both immunogenic and immunosuppressive properties after chondrogenic differentiation.

BACKGROUND AIMS: The chondrogenic differentiation potential of mesenchymal stromal cells (MSC), as well as their immunosuppressive properties, have been studied extensively. So far, only a few studies have addressed the question of whether MSC still retain their immunosuppressive qualities after transdifferentiation. In particular, the expression of immunogenic markers, such as human leukocyte antigen (HLA)-DR, after differentiation has never been investigated. METHODS: Chondrogenic transdifferentiation was induced in human adipose tissue-derived stem cell (ADSC) pellet cultures derived from 10 different patients, using 10 ng/mL transforming growth factor (TGF)-ß3. Samples were harvested over a time-course of 28 days and analyzed by immunohistochemistry and reverse transcription (RT)-polymerase chain reaction (PCR). The cytokine levels in the supernatants of the samples were measured semi-quantitatively by dot-blots and quantitatively by enzyme-linked immunosorbant assays (ELISA). RESULTS: Undifferentiated ADSC were negative for chondrogenic markers, as well as HLA-ABC and HLA-DR epitopes in immunofluorescence. In contrast, TGF-ß3-induced pellet cultures showed both expression of chondrogenic differentiation markers, such as transcription factor 9 (Sox 9), collagen type IIa and aggrecan, and an up-regulation of HLA-DR, beginning at day 7 after induction. Interferon-γ (INF-γ) is known to up-regulate HLA-DR. Therefore we measured INF-γ levels in the supernatants of TGF-ß3-induced pellets and, indeed, INF-γ was up-regulated during chondrogenesis in ADSC pellet cultures. However, both undifferentiated and TGF-ß3-induced ADSC also showed expression of immunosuppressive HLA-G and interleukin (IL)-10 up-regulation. CONCLUSIONS: These results suggest that the immunogenicity of adult stem cell-derived tissue should be tested in animal models before clinical trials for allogeneic engineered tissue are considered.

Multipotent stromal cells for autologous cell therapy approaches in the guinea pig model.

Multipotent stromal cells have become of increasing interest due to their potential to provide therapeutic approaches for autologous tissue repair. However, these cells are not well defined in the guinea pig, which represents an important model in hearing research. Adipose-tissue-derived stem cells (ADSC) and bone-marrow-derived stem cells (BMSC) were isolated from different donor sites, and growth curves were generated to judge the proliferation potential. Adipogenic, chondrogenic and osteogenic differentiation was induced and confirmed histologically. Finally, the capability of guinea pig ADSC to differentiate into neuron-like cells was investigated. With regard to the expansion potential, total cell number and doubling time, ADSC from the neck were the most suitable cells of the tested donor sites. Both ADSC and BMSC showed nearly identical behaviour and ability to undergo multilineage differentiation. Thus, we identified ADSC from the neck as a promising cell source for autologous cell-based approaches in hearing research using the guinea pig model.

Differentiation Behaviour of Adipose-Derived Stromal Cells (ASCs) Seeded on Polyurethane-Fibrin Scaffolds In Vitro and In Vivo.

Adipose-derived stromal cells (ASCs) are a promising cell source for tissue engineering and regenerative medicine approaches for cartilage replacement. For chondrogenic differentiation, human (h)ASCs were seeded on three-dimensional polyurethane (PU) fibrin composites and induced with a chondrogenic differentiation medium containing TGF-ß3, BMP-6, and IGF-1 in various combinations. In addition, in vitro predifferentiated cell-seeded constructs were implanted into auricular cartilage defects of New Zealand White Rabbits for 4 and 12 weeks. Histological, immunohistochemical, and RT-PCR analyses were performed on the constructs maintained in vitro to determine extracellular matrix (ECM) deposition and expression of specific cartilage markers. Chondrogenic differentiated constructs showed a uniform distribution of cells and ECM proteins. RT-PCR showed increased gene expression of collagen II, collagen X, and aggrecan and nearly stable expression of SOX-9 and collagen I. Rabbit (r)ASC-seeded PU-fibrin composites implanted in ear cartilage defects of New Zealand White Rabbits showed deposition of ECM with structures resembling cartilage lacunae by Alcian blue staining. However, extracellular calcium deposition became detectable over the course of 12 weeks. RT-PCR showed evidence of endochondral ossification during the time course with the expression of specific marker genes (collagen X and RUNX-2). In conclusion, hASCs show chondrogenic differentiation capacity in vitro with the expression of specific marker genes and deposition of cartilage-specific ECM proteins. After implantation of predifferentiated rASC-seeded PU-fibrin scaffolds into a cartilage defect, the constructs undergo the route of endochondral ossification.

Effect of Hypoxia on Proliferation and the Expression of the Genes HIF-1α and JMJD1A in Head and Neck Squamous Cell Carcinoma Cell Lines.

BACKGROUND/AIM: The aim of the study was to investigate the effects of hypoxia on proliferation and the expression of HIF-1α (hypoxia-inducible factor 1 alpha) and JMJD1A (jumonji domain 1A) in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: FaDu and HLaC78 cells were incubated for 1-24 h in hypoxia and normoxia. Cell proliferation, mRNA and protein levels of HIF-1α and JMJD1A were quantified by counting, PCR and western blot. RESULTS: Hypoxia led to a constant decrease in cell proliferation. Short hypoxia resulted in an increase in HIF-1α mRNA levels. This effect was reversed after longer incubation. The western blot for HIF-1α showed a maximum accumulation after 3-6 h of hypoxia. In FaDu cells, the concentration of JMJD1A reached a peak after 6 h and decreased thereafter, whereas in HLaC78 cells, it presented a second peak after 48 h. CONCLUSION: The transcription factors HIF-1α and JMJDA1 were confirmed as relevant hypoxia-dependent regulators of carcinogenesis in HNSCC.

Superparamagnetic Iron Oxide Particles (VSOPs) Show Genotoxic Effects but No Functional Impact on Human Adipose Tissue-Derived Stromal Cells (ASCs).

Adipose tissue-derived stromal cells (ASCs) represent a capable source for cell-based therapeutic approaches. For monitoring a cell-based application in vivo, magnetic resonance imaging (MRI) of cells labeled with iron oxide particles is a common method. It is the aim of the present study to analyze potential DNA damage, cytotoxicity and impairment of functional properties of human (h)ASCs after labeling with citrate-coated very small superparamagnetic iron oxide particles (VSOPs). Cytotoxic as well as genotoxic effects of the labeling procedure were measured in labeled and unlabeled hASCs using the MTT assay, comet assay and chromosomal aberration test. Trilineage differentiation was performed to evaluate an impairment of the differentiation potential due to the particles. Proliferation as well as migration capability were analyzed after the labeling procedure. Furthermore, the labeling of the hASCs was confirmed by Prussian blue staining, transmission electron microscopy (TEM) and high-resolution MRI. Below the concentration of 0.6 mM, which was used for the procedure, no evidence of genotoxic effects was found. At 0.6 mM, 1 mM as well as 1.5 mM, an increase in the number of chromosomal aberrations was determined. Cytotoxic effects were not observed at any concentration. Proliferation, migration capability and differentiation potential were also not affected by the procedure. Labeling with VSOPs is a useful labeling method for hASCs that does not affect their proliferation, migration and differentiation potential. Despite the absence of cytotoxicity, however, indications of genotoxic effects have been demonstrated.

[Voice disorders in asthma]. / Stimmstörungen bei Asthma bronchiale.

Aasthma is one of the most common chronic diseases with a prevalence of 5% in Germany. Nearly half of the patients complain about permanent voice disorders. Mucosal changes due to the obstructive respiratory disease as well as mucus abnormalities and regularly accompanying chronic rhinosinusitis may explain these symptoms. The additional influence of laryngopharyngeal reflux is discussed controversially. Additionally, dysphonia may as well occur due to side effects of the therapy with inhaled corticosteroids: the ingredients as well as physical effects may be responsible for the development of chronic laryngitis. The concomitant therapy by an ENT specialist is important in asthma-related voice disorders to identify the basic cause of dysphonia systematically and to intervene at an early stage.