Axel Lechner

Dr. Axel Lechner


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 July 2021 in Current Oncology
Verified
Journal Article
Open access
PDF file
KSKariem Sharaf
Kariem Sharaf
ALAxel Lechner
Axel Lechner
SHStefan Philipp Haider
Stefan Philipp Haider
RWRobert Wiebringhaus
Robert Wiebringhaus
CWChristoph Walz
Christoph Walz
PBPhilipp Baumeister
Philipp Baumeister
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. Samples were assessed for the expression of p16 as a surrogate for HPV-related disease and different molecular stem cell markers (ALDH1A1, BCL11B, BMI-1, and CD44). In the cohort, seven patients had HPV-related HNSCC; six thereof were oropharyngeal squamous cell carcinoma. While expression of BMI-1 and BCL11B was significantly lower in healthy mucosa than both tumor and lymph node metastasis, there were no differences between tumor and lymph node metastasis. In the HPV-positive sub-cohort, these differences remained significant for BMI-1. However, no significant differences in these three tissues were found for ALDH1A1 and CD44. In conclusion, this exploratory study shows that CSC markers BMI-1 and BCL11B discriminate between healthy and cancerous tissue, whereas ALDH1A1 and CD44 were expressed to a comparable extent in healthy mucosa and cancerous tissues.

1 June 2021 in Cancers
Verified
Journal Article
Open access
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KSKariem Sharaf
Kariem Sharaf
TETanja K Eggersmann
Tanja K Eggersmann
SHStefan Philipp Haider
Stefan Philipp Haider
SSSabina Schwenk-Zieger
Sabina Schwenk-Zieger
JZJiefu Zhou
Jiefu Zhou
FHFrank Haubner
Frank Haubner
Human adipose-derived stem/stromal cells (ASCs) are increasingly used as auto-transplants in regenerative medicine to restore tissue defects or induce wound healing, especially in cancer patients. The impact of ASCs on squamous cell carcinoma of the upper aerodigestive tract (UAT) including head and neck and esophageal squamous cell carcinoma (HNSCC and ESCC) is not yet fully understood. ASCs were cultured from subcutaneous, abdominal lipoaspirates of five patients, who received auto-transplants to the head and neck. Supernatants were tested for paracrine effects in functional in vitro assays of proliferation of HNSCC tumor cell line FaDu and ESCC cell line Kyse30, and their cell migration/invasion capacities in Boyden chambers, in addition to endothelial tube formation assay using human umbilical vein endothelial cells (HUVECs). All ASC-derived supernatants enhanced proliferation of FaDu cells, invasive migration, and tube formation by HUVECs, compared to controls. Of five patients’ lipoaspirates, ASC-derived supernatants of four patients increased proliferation and invasive migration in Kyse30 cells. The data suggests that ASCs can promote tumor cell proliferation, invasiveness, and neo-angiogenesis in these tumor cell lines of the UAT and HUVEC in a paracrine manner. Although clinical studies on the subject of oncological safety are still needed, these findings emphasize the importance of complete tumor removal before ASCs are used in the head and neck.

Verified
Journal Article
Open access
PDF file
ALAxel Lechner
Axel Lechner
SHStefan Philipp Haider
Stefan Philipp Haider
BPBenedikt Paul
Benedikt Paul
PBPablo F. F. Escrihuela Branz
Pablo F. F. Escrihuela Branz
AFAxelle Felicio-Briegel
Axelle Felicio-Briegel
KSKariem Sharaf
Kariem Sharaf
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. After completing a new extensive online Ear Nose Throat (ENT) examination course, we conducted a standardized clinical skills exam for nine different ENT examination items with 31 students. Using Likert scales, self-evaluation was based on questionnaires right before the clinical skills exam and objective evaluation during the exam was assessed following a standardized regime. Self-evaluation and objective evaluation were correlated. To compare the exclusive online teaching to traditional hands-on training, a historic cohort with 91 students was used. Objective examination performance after in-classroom or online teaching varied for single examination items while overall assessment remained comparable. Overall, self-evaluation did not differ significantly after online-only and in-classroom ENT skill teaching. Nevertheless, misjudgment of one’s skill level increased after online-only training compared to in-classroom teaching. Highest levels of overestimation were observed after online training in simple tasks. While gender and interest in ENT did not influence self-evaluation and misjudgment, higher age of participants was associated with an overestimation of skills. Medical students with online-only training during the COVID-19 pandemic achieved similar ENT examination skills to those with traditional on-campus training before the pandemic. Nevertheless, students with online-only training were more prone to misjudge their skills when they assessed their skills. Due to the COVID-19 pandemic, current medical students and graduates might therefore lack individual specific psychomotor skills such as the ENT examination, underlining the importance of presence-based teaching.

7 October 2021 in HNO
Verified
Journal Article
Open access
PDF file
KSKariem Sharaf
Kariem Sharaf
AFAxelle Felicio-Briegel
Axelle Felicio-Briegel
MWMagdalena Widmann
Magdalena Widmann
JHJohanna Huber
Johanna Huber
TETanja Kristina Eggersmann
Tanja Kristina Eggersmann
ALAxel Lechner
Axel Lechner
Zusammenfassung: Hintergrund: Ein zentrales Ziel des Medizinstudiums ist der Erwerb theoretischer und praktischer Kompetenzen. Es mangelt jedoch an Evidenz, wie der Erwerb von Kompetenzen in speziellen Untersuchungstechniken gemessen werden kann. ToSkORL (Teaching of Skills in Otorhinolaryngology) ist ein Projekt, das die studentische Selbstwahrnehmung ihrer Kompetenz bei speziellen Untersuchungstechniken der Hals-Nasen-Ohren-Heilkunde und des Kopf-Hals-Bereichs aus didaktisch-wissenschaftlicher Sichtweise beleuchtet. Methodik: Im Rahmen des Untersuchungskurses erfolgte eine standardisierte mündlich-praktische Prüfung zu neun verschiedenen Untersuchungstechniken. Vor der Prüfung erfolgte eine Evaluation der studentischen Selbsteinschätzung mittels Fragebogen, die Prüfung wurde mittels Checkliste durch die Prüfenden standardisiert geprüft. Selbst- und Fremdeinschätzung nach der Likert-Skala wurden korreliert. Die neun Untersuchungstechniken wurden jeweils 42-mal von insgesamt 91 Studierenden in gegenseitiger Untersuchung durchgeführt. Ergebnisse: Die Selbsteinschätzung der Kompetenz in den Untersuchungstechniken variiert erheblich, insgesamt schätzten Studierende ihre eigene Untersuchungskompetenz weitgehend unabhängig von Alter und Geschlecht meist realistisch ein. Studierende mit einem hohen Interesse an der Hals-Nasen-Ohren-Heilkunde gaben bessere Selbsteinschätzungen an, neigten jedoch auch eher zur Selbstüberschätzung. Bei Untersuchungen des mittleren Schwierigkeitsniveaus ergab sich die größte Divergenz von Selbst- und Fremdeinschätzung. Schlussfolgerung: Die studentische Selbsteinschätzung ist ein geeignetes Instrument zur Messung der Untersuchungskompetenz in der Hals-Nasen-Ohren-Heilkunde. Es sollte ein besonderer Fokus auf die Lehre vermeintlich mittelschwerer Untersuchungstechniken gelegt werden, da diese am stärksten über- und unterschätzt werden.

17 September 2024 in Heliyon
Verified
Journal Article
Open access
ALAxel Lechner
Axel Lechner
SHStefan P. Haider
Stefan P. Haider
PBPablo Escrihuela Branz
Pablo Escrihuela Branz
BPBenedikt Paul
Benedikt Paul
FKFatemeh Kashani
Fatemeh Kashani
KSKariem Sharaf
Kariem Sharaf
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. The study was designed as a prospective, single-institution medical education cohort study. Medical students (n = 54; 3rd/4th year, no previous head and neck examination skills) completed a comprehensive online training for basic head and neck examination skills 1–14 days before undergoing an OSCE on 5 different examination items (cervical lymph node examination, oral/oropharyngeal examination, otoscopy, Weber/Rinne hearing test, anterior rhinoscopy). Expert-evaluated theoretical knowledge and practical abilities were measured using Likert scales (1 = high proficiency to 5 = low proficiency). Participants self-evaluated their own skills before and after the OSCE (5-point Likert scales). Students achieved an overall good to medium skill level in basic head and neck examination after online training. Increased psychomotor complexity of tasks contributed to worse performance. Expert evaluation of practical skills was better in male participants and those who rated their preparation as thorough. Low/no misjudgment (discrepancy between self- and expert-evaluation) was observed in most participants, while high discrepancy levels (strong misjudgment) were mainly attributable to the students’ underestimation of their own abilities. Online training of head and neck examination skills is a cost- and resource-efficient introduction to skill training and was inevitable during the pandemic. However, it cannot replace practical hands-on training, especially in tasks with high psychomotor requirements. Refresher-courses could compensate for cancelled skill training during the pandemic.