Daniel Burkhart

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Apolipoprotein E (apoE) and its three major alleles (APOE2, E3, and E4) have been implicated in Alzheimer's disease and other neurological disorders. Little is known of the role apoE plays in normal brain function and pathology. To create a model to study apoE in brain, we have generated APOE transgenic mice using microinjection of allele-specific human(More)
We present a volumetric iso-geometric finite element analysis based on Catmull-Clark solids. This concept allows one to use the same representation for the modeling, the physical simulation, and the visualization, which optimizes the design process and narrows the gap between CAD and CAE. In our method the boundary of the solid model is a Catmull-Clark(More)
Cytochrome aa3 (cyt aa3) is the main catalyst of cellular oxygen consumption. The properties of cyt aa3 will define the tissue oxygen requirements and provide an insight into energy supply and demand. Currently dual-wavelength (605-590 or 605-620 nm) reflectance spectrophotometry is used to monitor cyt aa3 redox state in vivo. We have experimentally(More)
Amyloid precursor protein (APP) gene encodes the short peptide fragment amyloid-beta-protein present in senile plaque cores, cerebrovascular amyloid, and intracellular neurofibrillary tangles in Alzheimer disease (AD). Using in situ hybridization with biotin-labeled RNA probes, we found distinctive patterns of APP gene expression in different regions of(More)
In situ hybridization with biotinylated DNA and RNA probes derived from the 3' untranslated region of human neuron-specific or gamma gamma-enolase (NSE) permits histochemical detection of NSE mRNA in autopsy samples of human brain. In both aged controls and Alzheimer's disease (AD) patients, NSE probe hybridized with variable intensity to nerve cells in(More)
The reaction of cyanide with cytochrome aa3 in intact mitochondria is known to differ significantly from the reaction with the isolated enzyme. To examine the cyanide reaction with cytochrome aa3 in situ, we studied the spectral characteristics and the reaction kinetics of cyanide with reduced brain cytochrome aa3 in an isolated perfused rat head(More)
Progressive cholinergic axonal dystrophy, cholinergic denervation, and generalized gliosis begin in the prosimian primate species Otolemur at 10% of maximum life span. In these same animals, extensive cerebral beta-amyloidosis follows relatively more abruptly at 50% of maximum life span. In contrast, even at maximum life span, the prosimian primate species(More)
We present an adaptive subdivision scheme for unstructured tetrahedral meshes inspired by the √ 3-subdivision scheme for triangular meshes. Existing tetrahedral subdivision schemes do not support adaptive refinement and have traditionally been driven by the need to generate smooth three-dimensional deformations of solids. These schemes use edge bisections(More)
Apolipoprotein E polymorphic variants (ApoE-epsilon2, epsilon3, and epsilon4) are associated with the age of onset distribution and risk of Alzheimer disease. The question of whether ApoE is expressed at a comparatively low level in human neurons compared to astrocytes, or whether ApoE enters neuronal cytoplasm via altered endosomal metabolism is important(More)
We have examined the effects of uncoupling on electron transfer reactions and cell bioenergetics in rat brain in situ. The redox reactions of cyt aa3, cyt c and cyt b as well as the levels of phosphocreatine/inorganic phosphate ratio (PCr/Pi) were monitored in isolated perfused rat head, using optical and [31P]NMR techniques, respectively. In the first(More)