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The cytokeratins from various human tissue were isolated using chromatographic techniques. The cytokeratins were first extracted from crude tissue using high and low salt buffers. It was necessary to use a denaturing agent such as urea to solubilize the resulting cytokeratin pellet. Imidazole also seemed to help solubilize the pellet and a reducing agent such as 2-Mercaptoethanol was not needed as previously believed. The acidic cytokeratins were separated from the neutral-basic cytokeratins using a DEAE ion-exchange column. The acidic cytokeratin fraction was further separated on a moderately polar reverse phase column with an acetonitrile gradient to eluted the proteins. Tetramethylammonium tetrafluoroborate was added to the mobile phase to react with any unreacted silanol groups on the stationary phase and trifluoroacetic acid was added to ion pair with the protein. The peaks were analyzed for purity using two dimensional electrophoresis and monoclonal antibodies that recognize the cytokeratins.

Diss.--Åbo Akademi University, 2003. / Contient cinq articles publiés par l'auteur dans des revues scientifiques. Bibliogr. en fin de chap.

Staphylococcus aureus (S. aureus) is a medically important bacterial pathogen associated with many diseases and infections of the respiratory system, wound sites, surgical incisions, and other portals of entry and exit. S. aureus is able to invade cells via mechanisms that have yet to be fully characterized. Vimentin, a protein filament of the animal cell cytoskeleton, and phosphoinositide 3-kinase (PI3K), a family of kinases responsible for initiating several cell signaling events, were found to be associated with S. aureus invasion. Confocal microscopy revealed that the vimentin network in human umbilical vein endothelial cells (HUVECs) undergoes dynamic rearrangement in steady state under control conditions. However, cells infected with S. aureus demonstrated peri-nuclear collapse of the vimentin network. Pre-treatment with LY294002, a drug that inhibits PI3K activity, decreased invasion of S. aureus and paralyzed the vimentin network. These data suggest that PI3K mediates S. aureus infection and vimentin rearrangement. / Department of Biology

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In this work we apply the Adomian decomposition method to an orientation aggregation problem modelling the time distribution of filaments. We find analytical solutions under certain specific criteria and programmatically implement the Adomian method to two variants of the orientation aggregation model. We extend the utility of the Adomian decomposition method beyond its original capability to enable it to converge to more than one solution of a nonlinear problem and further to be used as a corrector in path following bifurcation problems.

Thesis (Ph. D.)--Lehigh University, 1996. / Includes vita. Includes bibliographical references (leaves 78-90).