Browsing by Subject "Virology"
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Item Factors Associated with Multi-Drug Resistance among Patients with Streptoccus pneumoniae Ear Infections(2004-05-01) Mendoza, Belinda A.; Francisco Soto Mas; Chiehwen Ed Hsu; Antonio ReneMendoza, Belinda A., Factors Associated with Multi-Drug Resistance among Patients with Streptoccus pneumoniae Ear Infections. Master of Public Health (Social and Behavioral Sciences), May 2004, 27 pp., 6 tables, 1 figure, references, 9 titles. Clinical trials play an important role in the development of new medical treatments. The purpose of this study is to describe patients participating in a clinical trial and at analyze the socio-demographic characteristics of patients with susceptible and multi-drug resistant Streptococcus pneumoniae ear infections. At the conclusion of this study, a socio-demographic description of clinical trial participants was obtained and the results were slightly younger than patients with susceptible S. pneumoniae ear infections and were more likely to attend day care.Item Interleukin-8: Baculovirus Expression and the Receptor Signal Transduction Pathway(1994-06-01) Kang, Xiaoqiang; Stephen R. Grant; Rafael Alvarez; Paula SumstomXiaoqiang, Kang., Interleukin-8: Baculovirus Expression and the Receptor Signal Transduction Pathway. Doctor of Philosophy (Biomedical Sciences), June, 1994, 150 pp., 4 tables, 36 illustrations, bibliography, 212 titles. The cDNA for human interleukin-8 (IL8) was subcloned from a bacterial source into the eukaryotic baculoviral vector expression system. Recombinant human IL-8 (rhIL-8) was synthesized and secreted from SF9 cells following infection of a recombinant virus harboring the full-length IL-8 structural gene. Recombinant human interleukin-8 was purified ([greater than] 600 fold) to homogeneity using preparative HPLC. The rhIL-8 preparation retained all of the physical, immunological, and biochemical properties of the natural product (monocyte-derived IL-8). Baculovirus vector expression coupled to preparative HPLC proved to be a very efficient method for large-scale recombinant interleukin production. Biochemical mechanisms that mediate IL-8 receptor-stimulated activities are poorly understood. In this study, I have explored the intracellular mechanism(s) induced by IL-8 in differentiated HL-60 cells. IL-8 induced a rapid and transient activation of phospholipase A2 in differentiated HL-60 cells. A consequence of phospholipase A2 activation was the release of arachidonic acid and the generation of lysophospholipids from membrane phospholipids. The IL-8 stimulated-arachidonic acid release was pertussis toxin and phospholipase A2 inhibitor sensitive, and protein kinase C independent. In contrast to another neutrophil chemotactic factor, fMLP, IL-8 did not stimulate the activation of phospholipase C and phospholipase D. When comparing the phosphorylation events induced by IL-8 and fMLP, I found that these two chemotactic factors triggered different protein phosphorylation profiles. Tyrosine phosphorylation of proteins was not detected following IL-8 stimulation in HL-60 cells. However, IL-8 stimulated the rapid autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaM kinase II). These results strongly suggest that the IL-8 receptor is closely coupled to the activation of PLA2 and that CaM kinase II is an integral component of IL-8 receptor signal pathway.Item Lethality of Staphylococcus in Murine Pneumonia is Due to Alpha-Toxin and Other Secreted Factors Regulated by AGR and SAR(2003-08-01) Overheim, Katie A.; Dan Dimitrijevich; Glenn Dillon; James CaffreyOverheim, Katie A., Lethality of Staphlococcus aureus in Murine Pneumonia is Due to Alpha-Toxin and Other Secreted Factors Regulated by agr and sar. Doctor of Philosophy (Biomedical Sciences), August, 2003, 91 pp, 6 Tables, 9 illustrations, bibliography, 106. The purpose of these studies was to determine if the S. aureus global regulators agr and sar play a role in staphylococcal pneumonia and if the virulence factors regulated by them contributed to the severity of staphylococcal pneumonia. To determine this, we established a pneumonia model in mice in order to identify if S. aureus global regulators agr and sar play a role in the pathogenesis of staphylococcal pneumonia. As well, we took steps to identify the extracellular factors responsible for the lethality in a murine model of staphylococcal pneumonia and determine if these factors involved in disease process could be used as targets for immune therapy. My work revealed that lethal pneumonia in a mouse model is dependent on the S. aureus global regulators agr and sar. This study also revealed that the lethality associated with our model is due to secreted factors, regulated by S. aureus global regulators agr and sar. Further investigation demonstrated the alpha-toxin is a major virulence factor involved in the lethality in our model. By generating an alpha-toxin deficient strain in S. aureus RN6390, we show a reduced virulence in our disease model. As well, antiserum to alpha-toxin, when administered with a lethal dose of S. aureus RN6390, we show a reduced virulence in our disease model. As well, antiserum to alpha-toxin, when administered a lethal dose of S. aureus RN6390, we show a reduced virulence in our disease model. As well, antiserum to alpha-toxin, when administered with a lethal dose of S. aureus RN6390 protected animals from death. By evaluating the role of alpha-toxin’s ability to contribute to lethality, we assessed numerous strains of S. aureus in our pneumonia model. We discovered that there was a correlation to alpha-toxin production levels and lethality in our pneumonia model. However, our study also demonstrated that alpha-toxin is not the only factor involved in the disease process.Item Morphological and Proliferative Changes that Occur in Rat Retinal Progenitor Cells Following Incubation with Retinoic Acid and RPE-Secreted Proteins(2006-08-01) Heath, Allison K.; Rustin E. ReevesHeath Allison K., Morphological and Proliferative Changes that Occur in Rat Retinal Progenitor Cells Following Incubation With Retinonoic Acid and RPE-Secreted Proteins. Master’s of Science (Cell Biology and Genetics), August 2006, 67 pp., 12 figures, bibliography. The principal objective of this research is to characterize virally-transformed rat retinal progenitor cells following stimulation by retinal pigment epithelial (RPE) cell secreted proteins and retinoic acid. Progenitor cells were isolated from explants of postnatal rat RPE cell in vitro. Isolated progenitor cells were cloned, analyzed by microscopy and proliferation bioassays, to determine if cell proliferation occurred. The isolated progenitor cells were analyzed for differentiation by Western blot analyses and immunocytochemistry. The rat progenitor cells cultured in RPE secreted proteins proliferated, but did not differentiate as shown by the presence of nestin and vimentin in these cells. Retinoic acid caused other progenitor cells to proliferate and differentiate, which is seen through the bioassays and Western blot analyses.Item The Population Abundance and Associated Geographic and Demographic Factors of the Dengue Vectors, Aedes Aegypti and Aedes Albopictus in Dallas County, TX, USA(2007-05-01) Stahl, Matthew S.; Sue Lurie; Joon-Hak LeeStahl, Matthew S., The Population Abundance and Associated Geographic and Demographic factors of the Dengue Vectors Aedes aegypti and Aedes albopictus in Dallas County, TX. Master of Public Health (Environmental Health), May 2007, 40 pp., 7 figures, 2 tables, bibliography, 72 titles. The risk for dengue outbreak was assessed in North Central Texas in 2006 in response to increased case numbers in Texas and Mexican states in 2005. Data were collected from 54 sites in Dallas County, TX using oviposition traps and estimates from U.S. Census and Sourcebook America databases. Higher vegetation and shade displayed more Aedes species; standing water also showed more Aedes albopictus. Lower home values and lower incomes corresponded to more Aedes aegypti; lower household density displayed more Aedes albopictus. Other socio-economic and demographic factors did not have significant association with abundance. The methodology of this study may serve as a model for assessment of dengue vector abundance in other regions.