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Lipid Targets Of The Antimalarial Trioxanes In Plasmodium Falciparum, Carmony Leah Hartwig

Biological Sciences Theses & Dissertations

Malaria is among the most debilitating diseases of man. The protozoan parasite, Plasmodium falciparum, causes over a million annual fatalities. The antimalarial trioxanes, exemplified by artemisinin, are among the few pharmaceuticals for which clinical resistance has not become widespread. Artemisinin is a naturally occurring sesquiterpene lactone, containing a unique endoperoxide pharmacophore. Despite extensive study, the precise antimalarial mechanism of action of trioxanes remains elusive. Heme iron-mediated cleavage of the endoperoxide within the parasite digestive vacuole is hypothesized to generate cytotoxic metabolites capable of alkylating heme and damaging cellular macromolecules. The hypothesis of this research is that the endoperoxide pharmacophore …

Prostate Cancer Biomarker Identification: A Comparative Study, Wenjuan Jiang

Computational Modeling & Simulation Engineering Theses & Dissertations

With the current development of proteomics techniques, the discovery of potential molecular biomarkers for early detection of prostate cancer has been greatly improved. In this thesis, we implemented five classifiers including the support vector machine (SVM), Bayesian Classifier, Decision Tree, Random Forest and the Multilayer perceptron (MLP) to test their effectiveness in prostate cancer biomarker identification using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) tissue imaging data. The classifiers were utilized to discriminate cancer mass spectra from normal ones for the data collected at the Eastern Virginia Medical School (EVMS). There are 94 7 spectra from normal tissues and 27 from …

Study Of The Dna Damage Complexes Within The Htlv-1 Tax Oncoprotein Interactome, Sidi Mehdi Belgnaoui

Theses and Dissertations in Biomedical Sciences

Human T-cell leukemia virus type 1 (HTLV-1) is a transforming retrovirus that can give rise to adult T-cell leukemia (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). Tax is a virally encoded oncoprotein that is involved in HTLV-1 mediated cellular transformation. It has been hypothesized that Tax induces genomic instability via repression of the cellular DNA damage repair response. Our laboratory has previously shown that the interaction between Tax and various proteins involved in the DNA-damage response pathway impairs the ability of these proteins to mount an efficient repair response. As part of these observations, we proposed that Tax induces …

Characterization Of Antibiotic Resistance In Vibrio Cholerae Isolated From Ships' Ballast And Other Environmental Sources, Frank Kornegay Thomson Iii

OES Theses and Dissertations

Ships' ballast has been implicated as a vector in the dispersal of invasive species into new environments. Numerous cases have been documented for the introduction of macroorganisms via ballasting operations, but what is less known is the role of ballast water and residuals in the spread of potentially harmful microbes, especially with reference to novel genotypes. Of particular interest are the genes encoding for various forms of antibiotic resistance, many of which are carried on mobile genetic elements. A four-year sampling effort has yielded over 300 putative isolates of Vibrio cholerae from ships' ballast tanks and various environmental sources, of …

Interdependent Regulation Of Cytomegalovirus Proteins In Complex, Lisa L. Bolin

Theses and Dissertations in Biomedical Sciences

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that causes significant morbidity and mortality in the immune compromised. Using the mutine cytomegalovirus (MCMV) model, we identified two genes, M140 and M141, which are determinants of macrophage tropism. Monocytes/macrophages are a critical cell type for cytomegalovirus (CMV) pathogenesis as sites of viral latency and by supporting viral replication and disseminating virus throughout the body. We previously found that the localization of the M140/M141 gene products (pM140/pM141) is different when the proteins are co-expressed as compared to their individual expression. When the proteins are individually expressed pM141 localizes diffusely throughout the cytoplasm and, …

Role Of The Human Cytomegalovirus Ie2 Protein On Transcriptional Regulation Of Viral Promoters, Siabhon Michelle Harris

Theses and Dissertations in Biomedical Sciences

Human cytomegalovirus (HCMV) is a ubiquitous pathogen able to cause severe mortality and morbidity in immuno-compromised individuals. Successful infection by HCMV is dependent on expression of viral genes essential for replication. Immediate early (IE) gene products are the first subset of viral genes to be expressed during infection and function as key transcriptional regulators. IE2 is one the most predominantly expressed IE proteins and is essential for HCMV infection. IE2 transactivates several viral promoters, including those of the essential viral DNA polymerase (UL54) and UL112-113 gene regions. IE2 is also able to autoregulate is own expression and repress expression of …

Comparison Of Immune Correlates, Age Related Changes And Proteomic Profiling Of Healthy Individuals Receiving Influenza Vaccines, Gaurav Basu

Theses and Dissertations in Biomedical Sciences

The burden of influenza related infections is substantial, both in terms of illness, lives lost and economic impact on society. The degree of impact of influenza related infections is much higher in the elderly population where it is a leading cause of catastrophic disability; greatly affecting the quality of life of elderly persons above 65 years of age. Vaccination is the mainstay for control and prevention of influenza infections. There are two vaccine formulations that are licensed for use at present. The inactivated influenza vaccines (TIIV) which have been used for 60 years in all age groups and the new …

Analysis Of N-Linked Oligosaccharides Of Prostate-Specific Antigen And Prostatic Acid Phosphatase In Prostatic Fluids, Krista Yaudes White

Theses and Dissertations in Biomedical Sciences

Presently, prostate cancer is the most common cancer afflicting men in the United States, with serum PSA being the "gold standard" protein biomarker used in the clinic for detecting and diagnosing prostate cancer. Nonetheless, serum PSA levels can also be elevated in non-cancerous conditions as well, such as benign prostatic hyperplasia (BPH). Due to this overlap, many unnecessary biopsies and radical prostatectomies occur, leading to patient distress. Despite recent advances to clinical assays which consider other clinical parameters, there is still a great need for improved clinical detection methodologies for prostate cancer, including improved biomarkers. Therefore, this research project aims …

Pge2 Receptor Subsets Mediate Hcg Regulation Of The Plasminogen Activator/Plasmin System In Primate Periovulatory Follicles, Nune Markosyan

Theses and Dissertations in Biomedical Sciences

Elevated follicular prostaglandin E2 (PGE2) levels are necessary for follicle rupture during ovulation. As the degradation of the follicle wall requires proteolysis, it was hypothesized that regulation of proteolysis by gonadotropins is PGE2 mediated.

There are four PGE2 receptors: EP1, EP2, EP3 and EP4. To determine which PGE2 receptors are present in monkey periovulatory follicles, granulosa cells and whole ovaries were collected 0, 12, 24, and 36 hours after administration of an ovulatory dose of human chorionic gonadotropin (hCG), or 36 hours after hCG from monkeys that received the prostaglandin (PG) synthesis inhibitor celecoxib. All EP receptor mRNAs were present …

In Vivo Murine Melanoma Tumor Responses To Nanosecond Pulsed Electric Field Treatment, Xinhua Chen

Theses and Dissertations in Biomedical Sciences

High intensity nanosecond pulsed electric fields (nsPEF) were applied to melanoma tumors to observe functional and structural biological changes and to investigate the possible molecular mechanisms responsible. An animal model was set up by injecting B16F10 mouse melanoma cells into SKH-1 mice. A treatment (Tx) of 100 pulses: 300 nanosecond duration; 40 kV/cm field strength; at 0.5 Hz rate were delivered to melanoma tumors in 120 mice. The nsPEF Txcaused tumor self-destruction with sharply decreased cell volumes and shrunken nuclei. The apoptotic biochemical tests confirmed nsPEF Tx induced apoptosis in a time-dependent manner. Examination of gross vessel and micro-vessel density …

Gene Therapy Using Tet-Repressor System To Modulate Prostate Tumor Microenvironment, Nazita Yousefieh

Theses and Dissertations in Biomedical Sciences

Prostate cancer is the most commonly diagnosed malignancy in men in the United States and is projected to be the third most frequent cause of male cancer-related deaths in 2007 after lung and skin cancers. The initial treatment for prostate cancer at early stages is prostatectomy or radiation, which usually is curative. However, approximately 20% of patients are not cured by such treatments and their cancer recurs, sometimes with long latencies. In other patients prostate cancer is diagnosed only after the cancer has metastasized and there are no effective therapies at this stage. Therefore immunotherapy seems to be a promising …

Improved Constrained Global Optimization For Estimating Molecular Structure From Atomic Distances, Terri Marie Grant

Mathematics & Statistics Theses & Dissertations

Determination of molecular structure is commonly posed as a nonlinear optimization problem. The objective functions rely on a vast amount of structural data. As a result, the objective functions are most often nonconvex, nonsmooth, and possess many local minima. Furthermore, introduction of additional structural data into the objective function creates barriers in finding the global minimum, causes additional computational issues associated with evaluating the function, and makes physical constraint enforcement intractable. To combat the computational problems associated with standard nonlinear optimization formulations, Williams et al. (2001) proposed an atom-based optimization, referred to as GNOMAD, which complements a simple interatomic distance …

Maldi Mass Spectrometry Imaging For The Discovery Of Prostate Carcinoma Biomarkers, Lisa Harris Cazares

Theses and Dissertations in Biomedical Sciences

The elucidation of new biological markers of prostate cancer (PCa) should aid in the detection, and prognosis of this disease. Diagnostic decision making by pathologists in prostate cancer is highly dependent on tissue morphology. The ability to localize disease-specific molecular changes in tissue would help improve this critical pathology decision making process. Direct profiling of proteins in tissue sections using MALDI imaging mass spectrometry (MALDI-IMS) has the power to link molecular detail to morphological and pathological changes, enhancing the ability to identify candidates for new specific biomarkers. However, critical questions remain regarding the integration of this technique with clinical decision …

Subcellular Localization Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein, Kimberly Anne Fryrear

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus that gives rise to Adult T-cell Leukemia (ATL) and a variety of other subneoplastic conditions such as HTLV-Associated Myelopathy/Tropical Spastic Paraperesis (HAM/TSP). In ATL, the transformation and immortalization of T-lymphocytes has been attributed to the expression and activity of a single HTLV-1 viral protein, namely the trans-activating protein Tax. Although the exact mechanism of Tax-mediated transformation is uncertain, current studies support a model in which Tax induces genomic instability in the host cell through interference with DNA repair mechanisms, dysregulation of cell cycle progression, transcriptional activation of cellular …

Serotype Association And Regulation Of The Hyaluronate Lyase Gene Of Streptococcus Pyogenes, Martha Stokes

Theses and Dissertations in Biomedical Sciences

S. pyogenes expresses many virulence factors, controlled by a complex regulatory network. These include hyaluronate lyase, an enzyme that degrades hyaluronic acid, a major component of the human extracellular matrix. Paradoxically, hyaluronic acid is also the sole component of the bacterium's capsule, a primary defense against the host immune response. The hylA gene, which encodes the enzyme, has been shown to take three structural forms: a full-length gene, one containing a 3' deletion and a gene that produces a prematurely truncated protein. This work was intended to show that the structure of hylA is associated with serotype, and …

Molecular Phylogenetics Of Perciform Fishes Using The Nuclear Recombination Activating Gene 1, Andrew R. Mahon

Biological Sciences Theses & Dissertations

The order Perciformes contains one-third of all extant fishes in twenty different suborders and over 10,000 species. Few systematic investigations have been performed on this large group of fishes at the suborder level and their evolutionary history is widely recognized as problematic. This dissertation presents three studies: a molecular phylogenetic analysis of the putative suborders of the order Perciformes, an analysis of interrelationships of the families of the perciform suborder Percoidei, and a multi-gene investigation of the percoid superfamily Sparoidea.

The taxa sampled in this dissertation represent one of the most inclusive molecular datasets, to date, testing the monophyly of …

The Effects Of Ultrashort Pulsed Electric Fields On The Fluorescent Molecule Bodipy Fl C5 Ceramide, Rachael Sara Shevin

Electrical & Computer Engineering Theses & Dissertations

Nanosecond pulsed electric fields are able to manipulate internal cell organelles by taking advantage of the small but finite time required for charge to establish across a capacitive barrier. Pulsed electric fields also affect macromolecular structures such as enzymes and proteins. Application of a single nanosecond pulsed electric field decreases the fluorescence of a commercially available biological dye Bodipy FL C₅ Ceramide, used to observe the Golgi apparatus of living cells. The effect is seen when the fluorophore is exposed to an electric field both in vitro and when incorporated into the Golgi of a living Jurkat cell. Observation …

Extracellular Superoxide Dismutase Protects Cardiomyocytes During Hyperoxia, Mervat Elsayed Ali

Theses and Dissertations in Biomedical Sciences

Reactive oxygen species are implicated in tissue damage in many cardiovascular diseases. The current study was designed to test the hypothesis that exposure to high inspired oxygen concentrations (100%) damages cardiac mitochondria and that a biogenic response is needed for cell survival. The study was done in mice with a transgene (TG) for extracellular superoxide dismutase (EC-SOD) or with the EC-SOD gene knockout (KO). Adult EC-SOD mice and their wild type littermates and EC-SOD KO mice and their wild type littermates were exposed to 100% oxygen for 6 hours and for 72 hours, and the hearts were subsequently removed under …

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and/or …

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult. …

Modulation Of Tgfβ-Induced Pai -1 Expression By Changes In Actin Polymerization In Human Mesangial Cells, Keyur Patel

Theses and Dissertations in Biomedical Sciences

Chronic renal diseases show increased deposition of extracellular matrix (ECM) in the glomerulus (glomerulosclerosis). Glomerulosclerosis is associated with activation of normally quiescent glomerular mesangial cells into myofibroblast-like cells. The overall objective of this study is to delineate cellular mechanism/s of myofibroblast-differentiation in disease states. In cultured mesangial cells certain characteristics of myofibroblast differentiation (α-smooth muscle actin (α-SMA) and hypertrophy) are associated with an increase in polymeric actin microfilaments (stress fibers). It is likely that other genes are also regulated in an actin cytoskeleton-dependent manner during myofibroblast differentiation. In these studies, we therefore examined the hypothesis that changes in the actin …

The Use Of Proteomic Technologies To Identify Serum Glycoproteins For The Early Detection Of Liver And Prostate Cancers, Elizabeth Ellen Schwegler

Theses and Dissertations in Biomedical Sciences

The application of proteomic technologies to identify serum glycoproteins is an emerging technique to identify new biomarkers indicative of disease severity. Many of these newly evolving protein-profiling methodologies have evolved from previous global protein expression profiling studies such as those involving SELDI-TOF-MS technologies. Though the SELDI approach could distinguish disease from normal by utilizing protein patterns as shown herein with the HCC study of chapter II, it was unable to offer sequence information on the selected peaks, and did not have the ability to analyze the entire dynamic range of the serum/plasma proteome. To address these deficiencies, new strategies that …

Isolation And Functional Mapping Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein Dna-Damage Complexes, Sarah Saionz Durkin

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus which causes Adult T-cell Leukemia (ATL) and HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Cellular transformation can be caused by a single viral trans-activating protein, Tax. Tax may contribute to transformation through interaction with components of the DNA damage response pathway, promoting cellular genomic instability. We examined cellular Tax complexes in an effort to elucidate potential protein-protein interactions that can model the Tax-induced molecular events.

We also investigated the role of post-translational modification in regulating Tax function. We employed a direct physical analysis of Tax complexes isolated from mammalian …

Chromosomal Localization Of The Islet Neogenesis Associated Protein (Ingap) Gene In Syrian Hamster By Tyramide Signal Amplification-Fluorescence In Situ Hybridization (Tsa-Fish), Sallie A. Smith

Biological Sciences Theses & Dissertations

Diabetes mellitus is a group of conditions characterized by hyperglycemia due to an inability to produce or properly utilize insulin. The majority of cases fall into two categories, Type I and Type 2. Type I results from the autoimmune destruction of pancreatic β-cells of the islets. The beta cells are the exclusive source of insulin and the patient becomes entirely dependent on exogenous insulin to survive. Patients with Type 2 are distinguished by insulin resistance, a condition that develops due to the inability of the body to effectively use the insulin being produced. The β-cells gradually lose their ability to …

The Antitumor Agent, Arglabin-Dma, Preferentially Induces Apoptosis In Human Colon Tumor Cells, Sung Wook Kwon

Theses and Dissertations in Biomedical Sciences

Arglabin-DMA, an analog of farnesyl pyrophosphate (FPP), reportedly inhibits farnesyltransferase (FTase) directly by competitively blocking the binding of Ras protein and its posttranslational modification, as suggested in previous studies. But, the mechanisms by which Arglabin-DMA inhibits tumor growth in vivo and in vitro are still relatively poorly characterized. To determine the mechanism by which this drug inhibits tumor growth, the effects of Arglabin-DMA in two human colon tumor cell lines (mutant K-ras HCT 116 and wild-type ras HT-29) were explored on cell proliferation, apoptosis, and cell cycle kinetics in vitro. In cell viability studies, we showed that Arglabin-DMA …

Mechanisms Of Cell Death Initiated In Herpes Simplex Virus Thymidine Kinase Expressing Colon Tumor Cells Treated With Ganciclovir And Ucn-01, Christina Elizabeth Ahn

Theses and Dissertations in Biomedical Sciences

Metastatic colon carcinoma is the second leading cause of death from malignancy in the United States, and development of more effective treatments is essential. Heterologous expression of Herpes Simplex Virus Thymidine Kinase (HSVtk) in combination with the prodrug, ganciclovir (GCV), has shown great promise for the genetic therapy of many cancers, but most patients have had only a partial or minimal response to the therapy. After screening a panel of two drug combinations, our laboratory has shown that the combination of GCV and the protein kinase inhibitor UCN-01 (7-hydroxystaurosporine) enhances tumor cell death more effectively than either drug alone. However …

Regulation Of Sparc Gene Expression By The Activator Protein 1 Transcription Factor, Joseph William Briggs

Theses and Dissertations in Biomedical Sciences

Overexpression of the c-Jun proto-oncogene in MCF7 breast cancer cells results in a variety of phenotypic changes related to malignant progression including a shift to estrogen independent growth, increased cell motility and invasion. Concurrent with these phenotypic changes are alterations to cellular gene expression patterns. One gene that becomes highly upregulated is SPARC (secreted protein acidic and rich in cysteine). Increased SPARC expression is associated with malignant progression in a variety of different cancers, although little is known regarding the mechanisms of SPARC gene regulation. Therefore, the objectives of this study were: (1) to determine the mechanisms by which c-Jun …

Tumor Response Tcf-4/Β-Catenin Regulatory Elements For Enhancing Cancer Gene Therapies, Saurabh Kumar Gupta

Theses and Dissertations in Biomedical Sciences

Mutations in the adenomatous polyposis coli gene are frequently associated with progression of colon carcinoma and most other types of epithelial carcinomas. This usually results in stabilization of β-catenin protein levels, followed by transactivation of Tcf-4/β-catenin responsive genes. The effectiveness of a Tcf-4/β-catenin transcriptional enhancer element in combination with a c-fos or carcinoembryonic antigen promoter was tested for its ability to act as a tumor specific regulator of gene expression in a panel of human tumor and normal cell lines. Luciferase reporter assays indicated enhanced activity of the Tcf-4/β-catenin transcriptional element only in tumor cell lines, with minimal activities in …

Hyaluronate Lyase Gene Of Streptococcus Pyogenes: Molecular Characterization And Regulation, Sheryl Lynne Walton

Theses and Dissertations in Biomedical Sciences

Streptococcus pyogenes causes an assortment of diseases ranging from pharyngitis to necrotizing fasciitis. This bacterium has the ability to elaborate several extracellular products capable of causing tissue damage; one of which is a hyaluronate lyase. Little information is available regarding the regulation of streptococcal hyaluronidase. As such, the expression of hylA in the hyaluronate lyase-producing strain ATCC 10403 and in strains that do not produce detectable enzyme was analyzed by RT-PCR and quantitative PCR. Hyaluronate lyase transcript was detected throughout growth for all strains; however, expression of hylA in the enzymatically inactive strains, 71698 and SF370, was determined …

The Quantitative Assessment Of Osteoinductivity Of Human Demineralized Bone Matrix And Cdna Array Analysis Of Osteogenic Differentiation In Human Periosteal Cells, Sittisak Honsawek

Theses and Dissertations in Biomedical Sciences

Demineralized bone matrix (DBM) has been extensively utilized in orthopeadic, periodontal, and maxillofacial applications. DBM comprises bone morphogenetic proteins (BMPs) that are essential regulators for endochondral bone formation. The current study was undertaken to establish the quantitative in vitro assays for determining the osteoinductive potential of human DBM and the use of cDNA gene expression array technology for examining gene expression profiles during osteoblast differentiation in human periosteal cells.

BMP-4 is one of the most osteoinductive factors and has been investigated for clinical applications. For this reason, BMP-4 was designated as the osteoinductive protein for use in the quantitative in …