ISSRNS 2012: Abstracts / Synchrotron Radiation in Natural Science Vol. 11, No 1 – 2 (2012) P 63
SYNCHROTRON RADIATION BASED STUDIES OF THE ELEMENTAL COMPOSITION AND CHEMICAL FORMS OF Fe AND Zn
IN BRAIN GLIOMAS
M. Szczerbowska-Boruchowska1∗, M. Lankosz1, M. Czyzycki1, A. Wandzilak1, P. Wrobel1, E. Radwanska2, and D. Adamek2
1AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. Mickiewicza 30, 30–059 Krakow, Poland
2Department of Neuropathology, Chair of Pathomorphology, Faculty of Medicine, Jagiellonian University Medical College, ul. Botaniczna 3, 31–503 Krakow, Poland
Keywords: synchrotron radiation, X-ray fluorescence, X-ray absorption near edge structure spectroscopy, brain gliomas
∗e-mail : Magdalena.Boruchowska@fis.agh.edu.pl
The literature published in recent years indi- cates an essential role played by minor and trace elements in a number of pathological processes in- cluding the carcinogenic process [1]. At present, there is a growing awareness of, and interest in, studies involving the determination of the elemen- tal composition of normal and malignant tissues [2].
However, the exact role of chemical elements in car- cinogenesis remains unknown. Synchrotron radia- tion XRF microprobe analysis (SRXRF) is a multi- elemental analytical technique which enables the si- multaneous micro-imaging of chemical elements at trace concentrations. For this reason, X-ray fluores- cence seems to be a promising tool for the investiga- tion of cancerogenesis. Moreover, the identification of the chemical forms of trace elements in tissue mi- crostructure may help us understand the carcino- genetic processes. In this work, X-ray absorption near edge structure spectroscopy (XANES) is ap- plied for the analysis of chemical forms of Fe and Zn.
The samples for biochemical micro-imaging were taken intraoperatively from brain tumors of dif- ferent types and various grades of malignancy.
The samples were diagnosed histopathologically at the Department of Neuropathology at the Jagiel- lonian University Medical College in Krakow.
The samples were prepared in two ways. In the first case the specimens referred to as “frozen samples,”
were cut to about 2 mm thick slices and placed in Plexiglas cups of 12 mm diameter. The containers were then covered with ultralene foil and frozen at
−80◦C. In addition, the so-called “dried samples”
were studied. For this purpose the specimens were cryo-sectioned at 20 µm, mounted onto 4 µm thick- ness ultralene foil suspended onto plexiglas holder, and freeze-dried at −80◦C.
The SRXRF measurements were performed at the bending magnet beamline L at HASYLAB.
The primary X-ray energy was set to 17 keV.
The beam was focused to a size of 15 µm in di- ameter. The sample areas were scanned to ob- tain two-dimensional images of elemental distribu- tions. Depending on the sample kind the XANES
measurements were carried out at different syn- chrotron facilities / beamlines. The “frozen sam- ples” were studied at the bending magnet beam- line C at HASYLAB. The “dried samples” were an- alyzed at the wiggler line SUL-X at ANKA syn- chrotron as well as the bending magnet beamline L at HASYLAB. The Fe and Zn XANES profiles were measured. Moreover, two-dimensional imaging of chemical forms of both elements was performed.
The SRXRF technique allowed for the identifica- tion of a two-dimensional distribution of P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb in neoplastic tissues on a micro-scale. The masses per unit area of elements were determined for various brain tumor types.
The quantitative analysis shows that for all cases the content of the oxidized form of Fe is significantly higher in comparison with Fe2+. The XANES anal- ysis showed that the content of either Fe2+ or Fe3+
is increased in low grade gliomas in comparison to high-grade malignant tumors. It was found that Zn in all tissue structures (homogeneous neoplastic tis- sue, calcifications, blood vessel) occurs in oxidized form.
Acknowledgments: This work was supported by:
− the Polish Ministry of Science and Higher Ed- ucation and its grants for Scientific Research (DESY/304/2006; N N518 377537),
− the European Community Seventh Framework Programme (FP7/2007-2013) under grant agree- ment n◦226716.
References
[1] M. Valko, C.J. Rhodes, J. Moncol, M. Izakovic, M. Mazur, “Free radicals, metals and antioxidants in oxidative stress-induced cancer,” Chem. Biol.
Interact. 160 (2006) 1.
[2] C. Theodorakou, M.J. Farquharson, “Classification of secondary colorectal liver cancer in human biopsy samples using angular dispersive x-ray diffraction and multivariate analysis,” Med. Phys. Biol. 54 (2009) 4945.
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