[Physical Properties of Squamous Cell Carcinoma Cells using Atomic Force Microscopy]. / Bestimmung elastischer Eigenschaften von Plattenepithelkarzinomzellen mittels Rasterkraftmikroskopie.

INTRODUCTION: Malignant and benign cells differ according to their elasticity. An atomic force microscope is a useful tool for measuring these mechanical cell properties. If cells of different dignity show different resonance behavior, due to their different elasticity, a selective ablation of specific tissue types by ultrasound would be possible. The goal is a highly selective ablation of tumor tissue without damaging healthy tissue. MATERIALS AND METHODS: We performed elasticity measurements of tumor cells (UD-01 cell line) with an atomic force microscope. In a further step, an ultrasound applicator has been positioned and the morphological changes of the cells during the treatment were documented. RESULTS: Different elasticities on the squamous cells were measured, depending on the location. Below a defined maximum amplitude the morphological cell changes were caused solely by ultrasonic excitation. SUMMARY: The atomic force microscope is suitable for the determination of the individual cell elasticity. The data collected could be the basis for treatment modalities that lead to a very selective damage for malignant cells.

Centrosome abnormalities in head and neck squamous cell carcinoma (HNSCC).

CONCLUSIONS: Numerical and structural centrosome abnormalities play a critical role in the tumor progression of in head and neck squamous cell carcinoma (HNSCC) and may provide useful information as a prognostic factor for these patients. OBJECTIVES: Centrosome alterations are often linked with aneuploidy, cell transformation, and tumor progress. We investigated centrosome abnormalities in HNSCC and correlated these variables to clinicopathological parameters and clinical follow up data of the patients. METHODS: Retrospective analysis of numerical and structural alterations of centrosomes in tumor tissues and corresponding normal epithelium (n=50 and 31, respectively). Immunohistochemistry was performed using an anti-gamma-tubulin antibody. Image acquisition was done by an Orthoplan microscope, centrosomes were segmented interactively, and area as well as mean optical density was measured. Aneuploidy was evaluated by fluorescence in situ hybridization in a subset of cases (n=29). RESULTS: Numerical and structural centrosome abnormalities differed significantly between normal squamous epithelium and tumor cells (both P<0.0001). Especially numerical centrosome abnormalities were significantly associated with T category and tumor stage (both P<0.0001) and the occurrence of distant metastasis (P=0.002 and P=0.019, respectively). Numerical centrosome abnormalities correlated also with disease free survival of the patients (P=0.032) as well as shorter overall survival (P=0.003).

Argyrophilic nucleolar organizer region counts in squamous cell carcinomas of the head and neck after irradiation and chemotherapy.

After irradiation or chemotherapy of tumors of the head and neck, histological alterations might be difficult to assess. In 30 cases of squamous cell carcinomas of the pharynx, changes in argyrophilic nucleolar organizer region (AgNOR) counts were investigated after therapy. After treatment a significant decrease of AgNOR counts was detected (P < 0.001). No significant differences could be found between groups treated with radiotherapy, chemotherapy or a combination of radiotherapy and chemotherapy. These findings suggest that AgNOR counts might be useful to assess cytotoxic effects on a subcellular level.

[The importance of electron microscopy in research and clinical otorhinolaryngology]. / Die Bedeutung der Elektronenmikroskopie für Klinik und Forschung in der Hals-Nasen-Ohren-Heilkunde.

The current state of electronmicroscopy in research and clinical applications in otorhinolaryngology is reviewed. The recognition of cytoarchitectonic relationships by means of transmission electronmicroscopy, tracer studies and freeze fracture technique provides functionally interesting findings on the sensory epithelium and the permeability barriers of the inner ear. Knowledge of the fine structure of the animal and human ear also facilitates the understanding of the pathomechanism of the inner ear. Experimental and clinical findings of seromucotympanon are also described, as well as the morphology of normal and diseased respiratory mucosa. A viral origin for laryngeal papilloma is clearly confirmed. New findings in the pathohistology of otosclerosis are described. Finally, the use of electronmicroscopy in the diagnosis of ENT tumours is considered. The demonstration of pathognomonic cell organelles is useful not only in the diagnosis of rare tumours, e.g. esthesioneuroblastoma or carcinoid. The epithelial origin of anaplastic tumours can also be shown or excluded. Electronmicroscopy also offers important clues in the case of neck metastases from an unknown primary tumour.