Publications by authors named "Axel Lechner"

Background/objectives: New teaching methods are warranted to meet the demand for increased flexibility in medical education while making optimal use of the limited resources of educators. The COVID-19 pandemic forced universities to resort to online-only teaching, even for training of psychomotor skills. The objectives of this study were: (I) to investigate the performance of students without previous experience in ear, nose and throat (ENT) examination after completing an asynchronous online teaching course in an objective standardized clinical examination (OSCE) and (II) to evaluate the degree of over- and underestimation of their abilities.

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Background: A parotid abscess (PA) is a complication of an acute bacterial parotitis with a potentially life-threatening course. To date, data on the diagnosis and therapy of PA is sparse and mostly consists of case reports or case series. Therefore, this study aimed at comprehensively analyzing the microbiological spectrum and the therapeutic management in a bi-institutional setting.

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Introduction: Early relapse and development of metastatic disease are some of the primary reasons for the poor prognosis of patients with head and neck squamous cell carcinoma (HNSCC). HNSCC is a heterogeneous disease which may develop in large premalignant fields of genetically altered cells. Yet knowing which individuals will progress and develop clinically significant cancers during their lifetimes remains one of the most important challenges of reducing HNSCC morbidity and mortality.

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Article Synopsis
  • Upregulation of the TCL1A proto-oncogene is linked to various aggressive B-cell and T-cell cancers, but its mechanisms, especially in the nucleus, are not fully understood.
  • Research showed that TCL1A influences lymphomagenesis in mouse models by altering nuclear organization and interacts with proteins that regulate the cell cycle and DNA repair, notably CDC20.
  • High levels of TCL1A correlate with faster cell cycle transitions, increased chromosome missegregation, and aneuploidy, suggesting TCL1A disrupts normal cell cycle control, potentially leading to more aggressive forms of cancer.
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The variable clinical course of follicular lymphoma (FL) is determined by the molecular heterogeneity of tumor cells and complex interactions within the tumor microenvironment (TME). IL-4 producing follicular helper T cells (T) are critical components of the FL TME. Binding of IL-4 to IL-4R on FL cells activates JAK/STAT signaling.

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In medical school, practical capacity building is a central goal. During the COVID-19 pandemic, a shift to online teaching methods in university was mandated in many countries to reduce risk of SARS-CoV-2 transmission. This severely affected the teaching of psychomotor ability skills such as head and neck examination skills, resulting in a share of students that have only been taught such ENT-specific examination skills with online courses; our study aimed to measure performance and capacity of self-evaluation in these students.

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Background: A central goal of medical school is acquisition of theoretical and practical competences. However, evidence on how capacity acquisition can be measured for special examination techniques is scarce. ToSkORL (Teaching of Skills in Otorhinolaryngology) is a project aimed at scientifically and didactically investigating students' self-evaluation skills in otorhinolaryngologic and head and neck examination techniques.

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Cancer stem cells (CSCs) are accountable for the progress of head and neck squamous cell carcinoma (HNSCC). This exploratory study evaluated the expression of molecular CSC markers in different tissues of HNSCC patients. Tissue specimens of primary tumor, lymph node metastases and macroscopically healthy mucosa of 12 consecutive HNSCC patients, that were treated with surgery and adjuvant radio(chemo)therapy upon indication, were collected.

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Article Synopsis
  • Human adipose-derived stem/stromal cells (ASCs) are being explored in regenerative medicine for their potential to heal tissue defects, especially for cancer patients, but their effects on squamous cell carcinoma in the upper aerodigestive tract are not fully known.
  • In a study involving ASCs isolated from the fat of five patients, tests showed that the supernatants (liquid extracts) significantly increased tumor cell growth and invasive behavior in specific cancer cell lines (HNSCC and ESCC) and promoted new blood vessel formation.
  • The results indicate that ASCs may enhance cancer cell proliferation and invasiveness, highlighting the need for thorough tumor removal prior to their therapeutic use, as further clinical research is necessary to understand the
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The role of B cells in antitumor immunity and their impact on emerging immunotherapies is increasingly gaining attention. B-cell effector functions include not only secretion of antibodies, but also presentation of antigens to T cells. A physiologic B-cell subset with immunostimulatory properties was described in humans, defined by a high expression of CD86 and downregulation of CD21.

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The immune response against cancer is orchestrated by various parameters and site-dependent specificities have been poorly investigated. In our analyses of ten different cancer types, we describe elevated infiltration by regulatory T cells as the most common feature, while other lymphocyte subsets and also expression of immune-regulatory molecules on tumor-infiltrating lymphocytes showed site-specific variation. Multiparametric analyses of these data identified similarities of renal and liver or lung with head and neck cancer.

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Immune-related adverse events have been described in 86%-96% of high-risk melanoma patients treated with immune checkpoint inhibitors (ICI), while in 17%-59% of cases these are classified as severe or even life-threatening. The most common immune-related adverse events include diarrhea, fatigue, hypothyroidism, and hepatitis. Bilateral uveitis and unspecific vertigo have been described in 1% of cases, respectively, in the pivotal studies of ICIs, but the affection of the vestibule-cochlear system has not been reported before.

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Thermal ablative therapies are standard treatments for localized hepatocellular carcinoma (HCC). In addition to local tumor destruction, ablation leads to abscopal effects in distant lesions most likely mediated by an anti-tumor immune response. Although microwave ablation (MWA) is increasingly substituting other ablative techniques, its systemic immunostimulatory effects are poorly studied.

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B lymphocytes are important players in immune responses to cancer. However, their composition and function in head and neck squamous cell carcinoma (HNSCC) has not been well described. Here, we analyzed B cell subsets in HNSCC (n = 38), non-cancerous mucosa (n = 14) and peripheral blood from HNSCC patients (n = 38) and healthy controls (n = 20) by flow cytometry.

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Tumor-infiltrating lymphocytes (TILs) are correlated to prognosis of several kinds of cancer. Most studies focused on T cells, while the role of tumor-associated B cells (TABs) has only recently gained more attention. TABs contain subpopulations with distinct functions, potentially promoting or inhibiting immune responses.

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Head and neck squamous cell carcinoma (HNSCC) is a frequent tumour arising from multiple anatomical subsites in the head and neck region. The treatment for early-stage disease is generally single modality, either surgery or radiotherapy. The treatment for locally advanced tumours is multimodal.

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Human papillomavirus type 16 (HPV16) is a major risk for development of oropharyngeal squamous-cell-carcinoma (OPSCC). Although HPV OPSCC metastasize faster than HPV tumors, they have a better prognosis. The molecular and cellular alterations underlying this pathobiology of HPV OPSCC remain elusive.

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Cancer immunotherapy by therapeutic activation of T cells has demonstrated clinical potential. Approaches include checkpoint inhibitors and chimeric antigen receptor T cells. Here, we report the development of an alternative strategy for cellular immunotherapy that combines induction of a tumor-directed T-cell response and antibody secretion without the need for genetic engineering.

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The composition of tumor-infiltrating lymphocytes (TIL) reflects biology and immunogenicity of cancer. Here, we characterize T-cell subsets and expression of immune checkpoint molecules in head and neck squamous cell carcinoma (HNSCC). We analyzed TIL subsets in primary tumors (n = 34), blood (peripheral blood mononuclear cells (PBMC); n = 34) and non-cancerous mucosa (n = 7) of 34 treatment-naïve HNSCC patients and PBMC of 15 healthy controls.

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Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous and aggressive tumor originating from the epithelial lining of the upper aero-digestive tract accounting for 300,000 annual deaths worldwide due to failure of current therapies. The natural killer group 2D (NKG2D) receptors on natural killer (NK) cells and several T cell subsets play an important role for immunosurveillance of HNSCC and are thus targeted by tumor immune evasion strategies in particular by shedding of various NKG2D ligands (NKG2DLs). Based on plasma and tumor samples of 44 HNSCC patients, we found that despite compositional heterogeneity the total plasma level of NKG2DLs correlates with NK cell inhibition and disease progression.

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Background: The pentaspan protein CD133 (Prominin-1) is a predictive marker and part of the signature of tumour-initiating cells (TICs) for various cancer entities.

Methods: The correlation of CD133 expression with clinical parameters was assessed in primary samples of head and neck squamous cell carcinomas (n=98) and normal mucosas (n=24).

Results: A gradual and inversely proportional correlation between CD133 expression in primary tumours and decreased overall survival was observed, along with a positive correlation with the presence of lymph node metastases.

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The pentaspan protein CD133 (Prominin-1) is part of the signature of tumour-initiating cells for various cancer entities. The aim of the present study was to investigate the impact of ectopic CD133 expression on tumourigenic properties of otherwise CD133-negative, non-tumourigenic cells in vitro and in vivo. CD133 was stably transfected into human embryonic kidney 293 (HEK293) which was then sorted for the expression of CD133.

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