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A new study’s results revealed that the distribution of metal ions in the brain tissue of Parkinson’s disease sufferers is altered by the disease process.
It is estimated that four million people worldwide are suffering from Parkinson’s disease, a complicated disease that varies greatly among affected individuals. Understanding the brain chemistry that leads to the onset of Parkinson’s is crucial for developing methods for early magnetic resonance imaging (MRI) diagnosis and new treatments for this debilitating disease.
In February 2009 at the American Association for the Advancement of Science (AAAS) annual meeting in Chicago, IL, USA, Dr. Joanna Collingwood, from Keele University (UK), presented new results from studies conducted in collaboration with Dr. Mark Davidson from the University of Florida (UF; Gainesville, USA), at Diamond Light Source (Didcot, UK)--the United Kingdom’s national synchrotron facility.
Dr. Collingwood commented, “Our studies at Diamond involve a technique called microfocus spectroscopy, in which powerful, tightly focused beams of X-rays penetrate our tissue samples. We have been able to investigate human tissue with such precision that metal ions, particularly iron levels, in and around individual cells can be mapped. What makes the microfocus synchrotron approach so unique is that we can also use the focused beam to obtain information about the form in which the iron is stored. Thanks to several years of work on optimizing the tissue preparation method at the Materials Research Collaborative Access Team at the Advanced Photon Source [APS; Argonne (US) National Laboratory; Argonne, IL, USA] led by Dr. Davidson and Drs. Jon Dobson, of Keele and Chris Batich of UF, the technique is pioneering in that it does not change the distribution or form of the metals in the tissue being studied. We are grateful to the National Institutes of Health [NIH] in the USA for supporting this vital work. The impact of tissue preparation on the metal ions has been overlooked in many research projects in this area to date.”
By studying the tissue as a whole, it has been possible to map metal distribution throughout the brain region containing the vulnerable motor neurons in Parkinson’s disease in a region where they had earlier shown in earlier research that iron levels almost double in individual cells.
“To move this research on into the clinical arena, we need to determine how much the contrast change seen by clinicians in the MRI scan results is directly due to changes in iron distribution and form. Improving our understanding of the biochemical aspects of the disease should in the long term contribute to improved therapeutic approaches and also provide potential openings for early MRI detection and diagnosis. Early diagnosis is key because we know that by the time a typical individual presents with the symptoms of the disease, chemical changes have already caused significant cell death of vulnerable motor neurons. We have been working closely with Dr. John Forder and Dr. Keith White at the Mcknight Brain Institute at UF to begin MRI studies of early diagnosis and translate the results from Diamond and the APS in Chicago into clinical relevance.”
Due to the aging of the world population, the significance of Parkinson’s disease as a public health issue is increasing. The fundamental goal of this research is to find a method for early diagnosis so that medical treatment can begin as soon as chemical changes are detected and before the irreversible cell death takes place.
Treatment to remove or inactivate metals in the body is already available for individuals suffering from iron overload disorders, and is known as chelation therapy. As improvements in scanning techniques enable earlier detection of changes in the brain, it may be possible to diagnose Parkinson’s disease much earlier, and with additional developments in therapeutic research, discover chelation-based therapeutic approaches for patients to intervene before they experience irreversible levels of cell loss. In the case of Parkinson’s disease, a more targeted approach is needed, as the overall systemic iron levels are not elevated. Instead, local regions affected by the disease are involved, making the data obtained by the synchrotron techniques more critical to the design of appropriate treatments.
Diamond generates extremely intense pinpoint beams of synchrotron light of exceptional quality ranging from X-rays, ultra-violet and infrared. For example, Diamond’s X-rays are around 100 billion times brighter than a conventional hospital X-ray machine or 10 billion times brighter than the sun. Many of everyday commodities, including food manufacturing to cosmetics; innovative drugs; surgical tools; computers; mobile phones, have all been developed or improved using synchrotron light. |
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发表于 2009-3-13 10:59:43
