Physical Sciences and Mathematics Commons^™

Modified Electrodes With Grafted Dna And Oligonucleotides For Detection And Quantification Of Peroxynitrate, Heba Azmy Salim

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Peroxynitrite (ONOO-) is a strong oxidizing and nitrating agent, and its formation has been correlated with many pathological conditions. It is generated in-vivo through the diffusion-controlled reaction between nitric oxide and superoxide. Peroxynitrite has been linked to nitration of protein and DNA as well as to DNA strand breaks. Accumulation of mutations and/or other kinds of DNA damage represent a carcinogenic risk. The accurate measurement of peroxynitrite concentration has been a challenge since this analyte is very unstable and reacts with many cellular targets. Development of analytical techniques capable of rapid and sensitive detection of this fast-reacting and damaging agent …

Profiling Cell Surface Sialylation And Desialylation Dynamics Of Immune Cells, Dan Wang

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Sialic acids (SAs) are a diverse family of naturally occurring 2-keto-3-deoxy-nononic acids that are involved in a wide range of biological processes, including early fetal development, cellular recognition, and utilization by microbes. While it is clear that cell surface SAs are highly involved in the immune system, the sialylation status of individual immune cells and functions are still unknown. In this study, I combined the newly developed LC-MS/MS methods with flow cytometry and confocal microscopy to systematically study the sialylation and desialylation dynamics of macrophages at different conditions.

First, I developed an accurate LC-MS/MS method to quantify free SA in …

Development And Validation Of Uplc/Ms/Ms Methods For Quantification Of Gangliosides In The Clinical Study Of Ganglioside Gm3 Synthase Deficiency, Qianyang Huang

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Gangliosides are a large subclass of glycosphingolipids that structurally characterized by the addition of mono- or poly-sialyated carbohydrate moieties onto the ceramide scaffold. They are presented at significant abundance in the central nervous system of vertebrates. Their interactions with trans-membrane receptors, especially receptor tyrosine kinase, are believed to play critical roles in modulating signal transduction events during cell proliferation, differentiation, migration, and adhesion. Furthermore, the disruption and dysfunction on their metabolism have been found to be associated with various neurodegenerative disorders, such as Alzheimer disease, Parkinson’s disease, and GM3 synthase deficiency. GM3 synthase deficiency (GSD) is a newly identified neurological …

Study Of Electron Transfer Through The Reductase Domain Of Neuronal Nitric Oxide Synthase And Development Of Bacterial Nitric Oxide Synthase Inhibitors, Yue Dai

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Crystal structure of neuronal Nitric Oxide Synthase reductase (nNOSr) implies that large-scale domain motion is essential for electron transfer. However, the details are not well understood. To address this, we generated a functioning “Cys-lite” version of nNOSr and then replaced the nNOSr Glu816 and Arg1229 residues with Cys in the FMN and FAD domains (CL5SS) in order to allow cross-domain disulfide bond formation under pH 9 or to cross-linking using bis-maleimides. Cross-linked CL5SS exhibited a =95% decrease in cytochrome c reductase activity and reduction of the disulfide bond restored the activities. The results demonstrate that a conformational equilibrium involving FMN …

The Role Of Rnase L In Type I Diabetes And Development Of Quantitative Lc-Ms/Ms Methods For The Pharmacological Studies Of Anti-Cancer Drug Candidates, Chun Zeng

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PROJECT I: The cause of type I diabetes continues to be a focus of investigation. In this study, we found that 2-5A dependent RNase L (RNase L), an IFN-a-inducible enzyme that functions in IFN action against viruses and cell proliferation, played an important role in dsRNA-induced onset of type I diabetes. By using RNase L deficient RIP-B7.1 mice which are more vulnerable to environmental harmful factors such as viral infection, we demonstrated that deficiency of RNase L in mice resulted in a significant delay of diabetes onset induced by polyinosinic:polycytidylic acid (poly I:C), a type of dsRNA, and streptozotocin (STZ). …

Application Of Advanced Analytical Technologies To Drug Development Studies And Cancer Detection, Ramakrishna Reddy Voggu

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In the past decade, bioanalytical method development has become an integral part of the clinical diagnosis, biomarker discovery, and drug discovery and development. The new and emerged bioanalytical techniques allow the quantitative and qualitative analysis of bio molecules with remarkably high sensitivity and specificity. Specifically, these bioanalytical methods based on LC-MS and methylation-specific PCR are well suited for detecting low-abundance metabolites in various biological fluids and DNA in plasma and tissues for biomarker investigation. They offer great clinical promise for early disease diagnosis and therapeutic intervention. This dissertation broadly organized into two parts, part one talks about the application of …