Geert Hebbrecht

Brain trace elements and aging

Abstract Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process.

Examination of the regional distribution of minor and trace elements in normal human brain by PIXE and chemometric techniques

Abstract Particle-induced X-ray emission (PIXE) was used to measure two minor and six trace elements, i.e. K, Ca, Mn, Fe, Cu, Zn, Se and Rb, in up to 50 different structures (regions) of brains from Belgian individuals without neurological disorders. The data matrix with the mean dry-weight elemental concentrations and mean wet-to-dry weight ratio (means over 18 brains) for the various structures was subjected to two chemometric techniques, i.e., VARIMAX rotated absolute principal component analysis (APCA) and hierarchical cluster analysis. Three components were identified by APCA: components 1 and 3 represented aqueous fractions of the brain (respectively the intracellular and extracellular fluid), whereas component 2 apparently represented the solid brain fraction. The elements K, Cu, Zn, Se and Rb were predominantly attributed to component 1, Ca to component 3 and Fe to component 2. In the hierarchical cluster analysis seven different agglomerative cluster strategies were compared. The dendrograms obtained from the furthest neighbor and Wards error sum strategy were virtually identical and they consisted of two large clusters with 30 and 16 structures, respectively. The first cluster included all gray matter structures, while the second comprised all white matter. Furthermore, structures involved in the same physiological function or morphologically similar regions often conglomerated in one subcluster. This strongly suggests that there is some relationship between the trace element profile of a brain structure and its function.

Comparison of Trace Element Alterations and Water Content in Haemorrhagic and Non-Haemorrhagic Cerebral Infarcts

The concentration of eight elements (i.e., K, Ca, Mn, Fe, Cu, Zn, Se, and Rb) and the water content were determined in postmortem samples of recent cerebral infarcts. The elemental determinations were

Trace element changes in cardiovascular diseases

Abstract Artery samples and five different brain structures originating from both atherosclerosis affected and healthy Portuguese individuals were examined for their elemental content. Particle-induced X-ray emission (PIXE) was used to determine K, Ca, Mn, Fe, Cu, Zn, Se and Rb in all the tissues studied. The most prominent differences between the pathological and reference data were those for Mn, Fe, Cu and Zn in the nucleus caudatus, putamen and substantia nigra brain regions. In the arteries a significant increase in Ca and Mn content was observed, whereas the K and Fe content declined. The decreased K and Rb content in the five brain structures from the pathological group and the changes for Mn in the nucleus caudatus, putamen and substantia nigra regions can be associated with aging. However, age cannot explain the other trace element alterations, e.g., for Fe, Cu and Zn. Most likely, the changes for these elements are due to atherosclerosis progression.

Influence of Neurotropin on the Water Content and Regional Distribution of Two Minor and Six Trace Elements in Human Brains Affected by Recent Middle Cerebral Artery Infarcts

The water content and concentration of eight elements (i.e. K, Ca, Mn, Fe, Cu, Zn, Se and Rb) were measured in postmortem samples of recent cerebral infarcts in the territory of the middle cerebral ar