Application of laboratory and digital techniques for visual enhancement during the ultrastructural assessment of cilia

ABSTRACT

Routine diagnostic electron microscopy of primary ciliary dyskinesia (PCD) is based on the findings of ultrastructural defects of axonemal components. Assessment of the typical abnormalities can be enhanced by improving the sample preservation status using tannic acid (TA) as additive in the biopsy fixation or processing steps. Another option is the implementation of computer-assisted image analysis tools. Advancements in high-resolution 3D visualization of the axonemal structure have been noted, with great potential for the future diagnosis of inherited cilia disorders.

KEYWORDS:

• Cilia
• computer-assisted
• diagnostic
• image analysis
• tannic acid

Acknowledgments

For responding to the email enquiry on the current use of tannic acid additive in ciliary sample processing, and providing images for Figure 2, many thanks go to Jörg Bedorf/Uniklinikum Bonn, Germany; Estelle Escudier/Hospital A. Trousseau, Paris, France; Patricia Goggin/Biomedical Imaging Unit, University Southampton, UK; Valerija Groma/Anatomy, University Riga, Latvia; M.John Hicks/Pediatric Pathology, Texas Children’s Hospital, Houston, TX; Kyriacos Kyriacou/Cyprus School of Medicine, Nicosia, Cyprus; Gary Mierau/Pathology, Children’s Hospital Colorado, Aurora, CO; Heymut Omran and Anja Robbers/Department of Pediatrics, University Hospital Muenster, Germany; Jeannete Pankras/Pathology, Academical Medical Centre, Amsterdam, the Netherlands; Andreia Pinto/Instituto de Medicina Molecular, Lisbon, Portugal; Andrew Rutmann/National Primary Ciliary Diagnostic & Research Centre, University of Leicester, UK; Marco Santucci/Pathology, University Florence, Italy; Amelia Shoemark/National Hearth & Lung Institute, Royal Bromton Hospital, London, UK; Dirk Theegarten/Pathology, Uniklinikum Essen; Germany; and Bart Wagner/Histopathology, Teaching Hospital Sheffield, UK.

Special thanks go to my laboratory co-workers, Claudia Fischer (formerly Grafe) and Heiko Siegmund, Regensburg, for excellent technical support; to Prof. Christoph Palm and Matthias Semmelmann from the Regensburg Medical Image Computing Center OTH Regensburg for implementation of the computer-assisted tool (and continuing improvement) as well as to Brian Eyden (formerly of the Christie NHS Foundation Trust, Manchester, UK), for linguistic revision of the manuscript.