Browsing by Subject "Cells"

Now showing 1 - 4 of 4
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    Axial-scan fluorescence fluctuation spectroscopy: initial development and experimental challenges.
    (2010-05) Chen, Yun
    Summary abstract not available.
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    Characterization of UMD227 cells: a novel murine mammary cancer cell line.
    (2010-05) Redbrook, Shannon Marie
    Breast cancer is a heterogeneous disease, which makes it a challenging disease to treat. Breast cancer can be classified by histology as well as by molecular markers. In order to develop a relevant in vitro model, our lab has cloned and isolated a cell line, UMD227, from a mammary tumor of our mouse model which expresses transforming growth factor alpha under control of promoter, neu-related lipocalin (NRL-TGFα). When UMD227’s are transplanted back into our mouse model the resulting UMD227 tumors exhibit a higher grade than the primary tumor from which the cell line was derived and tumors following transplant have a distinct spindle cell like morphology, suggesting mesenchymal like characteristics. These characteristics suggest that this cell line represents basal-like tumor characteristics. My hypothesis was that the UMD227 cell line is a model of basal-like breast cancer. I began by determining the biological response of UMD227 cells to estrogens and antiestrogens in vitro and evaluation of marker proteins that distinguish mature differentiated epithelial cells from cells undergoing epithelial mesenchymal transition from progenitor/stem cells. My research concludes that the UMD227 cells are basal-like mammary gland cancer cells.
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    Encapsulation of proteins and cells in silica nanoporous materials
    (2011-11) Reategui, Eduardo
    My dissertation presents fundamental and practical scientific contributions. I demonstrated the versatility of the sol-gel processing technology for the study of the basic science behind water and protein structure under confinement, and for the development of novel biotechnology and biomedical engineering applications based on cell encapsulation in nanoporous silica gels.For the basic science studies of my dissertation, silica nanoporous gels were used to investigate the kinetic and thermodynamic transitions of water under confinement. I demonstrated a direct correlation between the structure of confined water and the secondary structure of proteins in a wide range of temperatures (- 196C to 95C). I showed qualitatively that the incorporation of a highly hydrogen bonding osmolyte contributed to improve the thermal stability of encapsulated proteins by a mechanism based on prevention of adsorption at the surface of the nanoporous silica material. For the practical contributions of my dissertation, I developed two novel applications relevant to the biotechnology and biomedical engineering fields. These applications were based on the encapsulation of prokaryotic and eukaryotic cells in silica nanoporous gels. First, I developed a highly selective and efficient biodegradation platform for the removal of an herbicide, atrazine, from contaminated water. In the second application, I invented a cell capture and isolation methodology that was successfully tested as a cancer cell isolation tool from mixed populations of eukaryotic cells (normal and cancer cells). Miscellaneous applications were also investigated such as encapsulation as a means of cryopreservation of mammalian and algae cells, and were incorporated in the Appendices of this thesis.
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    Microtubule tip tracking and tip structures at the nanometer scale using digital fluorescence microscopy.
    (2010-06) Demchouk, Alexei Olegovich
    The main aim of this work was to develop necessary tools and methods in order to improve the quality of study of microtubules in vivo using digital fluorescence microscopy. Through combination of microtubule modeling, model convolution, creating programs for automated image analysis, and imaging itself, such issues as using fixed samples with long exposure times can be overcome. We used the MATLAB® numerical computing environment to create computer scripts that are able to analyze images obtained via digital fluorescence microscope and get important insights about the dynamic nature of microtubules and their tip structures in vivo. The foundation of this project was our previously published MATLAB® microtubule contour tracking code [37]. After necessary modifications to the script had been made, the testing the MATLAB® code on the simulated images of microtubules revealed the typical accuracy of tip tracking in living LLC-PK1 cells with our microscope system was around 36 nm, but it could be as good as ~15 nm if observed microtubule tips are blunt. By using the same algorithm, we also have established that most microtubules within living cells are not blunt, but exhibit highly variable tapered structures (p-value<10-69). Using our conversion tables we were able to determine the mean taper length of microtubules within living LLC-PK1 cells to be 418 nm (with the standard deviation of 420 nm) and in fixed cells of the same type it was 387 nm (with 420 nm as the standard deviation).