Artikel
Visualisation of medulloblastoma cell cultures with 5-aminolevulinic acid-induced protoporphyrin IX (Pp IX)
Visualisierung von Medulloblastomzellkulturen mit 5-Aminolevulinsäure-induziertem Protoporphyrin IX (Pp IX)
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Autoren
Veröffentlicht: | 23. April 2004 |
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Gliederung
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Objective
Medulloblastoma are among the most frequent primary brain tumors in children. They often infiltrate adjacent areas, such as brainstem or 4th ventricle. The extent of resection influences the response to further therapies and the survival time. It is therefore interesting to study the characteristics of fluorescence of medulloblastomas after application of 5-aminolevulinic acid (5-Ala) according to the experience made with glioblastomas.
Methods
A total of 6 various primary cultures of medulloblastomas and rat neurons were transferred to NUNC 8-well chamber slides under physiological conditions, incubated with 5-Ala (Medac, Hamburg, Germany) [1 mg/ml] for 5, 10, 15, 30, 60, 90 and 120 minutes, then covered up after having been washed twice with PBS in a fluorescence-stabilising medium (DakoTM) and examined under a fluorescence microscope using a filter set specified for Pp IX. Fluorescence intensity was measured by using a digital imaging process. The high-resolution digital images were interpreted using the software Analysis DOKUTM with regard to their specific horizontal intensity of fluorescence (grey tone measurement). The data gained by this method were further analysed statistically.
Results
According to our preliminary results, medulloblastomas do not significantly differ from rat neurons in their fluorescence intensity after incubation with 5-Ala. Corresponding to our previous findings, 5-Ala is prevalently metabolised in the cytoplasm of the cells to Pp IX. Medulloblastoma cells have a large nucleus and only a small amount of cytoplasm, which is probably one reason for our observation.
Conclusions
According to primary bio-cellular ex-vivo examinations, 5-Ala obviously is not a suitable marker for the fluorescence-operated visualisation of medulloblastomas.