Browsing by Subject "Viruses"
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Item Assessment and Identification of Areas for Improvement of a Local Health Department Food Safety Program(2008-05-01) Harris, Ann MarieHarris, Ann Marie. Assessment and Identification of Areas for Improvement of a Local Health Department Food Safety Program. Master of Public Health (Environmental Health), May 2008, 14 pp. 1 table, 1 figure, references, 14 titles. The Fort Worth Public Health Department (FWPHD) established a standardized assessment to compare compliance rates for risk factors contributing to foodborne illness. The FWPHD identified significantly higher compliance rates in four out of six risk factors. Risk factors posing the greatest risk for out of compliance observations included threats from contaminated equipment and chemical/other hazards. Fast food establishments had a significantly greater risk for contaminated equipment (OR=1.81; CI=1.27, 2.58). Chemical/other hazards was the only risk factor with a higher overall out of compliance rate than the FDA. The FWPHD can now accurately track the effectiveness of training and education programs for food handlers, consumer health specialists, and the overall inspection process.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 T-Helper Cell Responses in Lungs After Immunization and Chronic Respiratory Disease; And Their Association With Pulmonary Inflammation(2001-05-01) Jones, Harlan P.; Simecka, Jerry; Dimitrijevich, S. Dan; Goldfarb, Ronald H.The purpose of these studies was to characterize T helper cell responses in the lungs of mice after immunization and chronic respiratory infection. CD4+ T cells were the major population of T cells resident in the lung in comparison to CD8+ T cells. Polyclonal activation of resident CD4+T cells produced abundant levels of IL-4 in comparison to IFN-γ, indicating that Th2 cells were the major sub-population of CD4+ T cells. In contrast, resident CD8+ T cells were the sole producer of IFN-γ by naïve T lymphocytes. Furthermore, the distribution of T cells was similar between BALB/c, C3H/HeN, C57BL/6 and DBA/2N strains of mice. However differences in the distribution of CD8+T cells, as well as the levels of IL-4 and IFN-y production produced by resident T cells were found between C57 and the other strains of mice tested. These results demonstrate that host genetic factors may be involved in determining host susceptibility to respiratory disease. Differences in the intensity of antigenic stimulation provoke changes in the type of T cell response generated. Intranasal immunization with influenza (FLU) vaccine antigen alone initiated solely an antigen-specific Th2-like response. In contrast, the addition of the potent mucosal adjuvant cholera toxin (CT) in combination with FLU antigen induced not only resident Th2 responses, but also induced antigen-specific Th1-like responses. This change corresponded with a dramatic increase in the number of CD4+ T cells in the lung. Thus, intense immunization of respiratory T cells enhanced resident T helper cell responses, but also promoted the activation of Th1 responses. Chronic respiratory infection also elicited changes in the resident population of T cells consistent with pulmonary inflammatory immune responses. At early stages of infection, CD4+, but not CD8+ T cells increased in number within inductive respiratory lymphoid tissues (lower respiratory nodes [LRNs]). Between day 7 and 14 however, there was a dramatic increase in the number of CD4+ T cells in the lung. Interestingly, CD8+ T cells also increased in the lungs, suggesting their activation along mucosal sites during mycoplasma infection. Mycoplasma-specific IL-4 and IFN-γ production also increased in a tissue-specific/time-dependent manner. IL-4 production was initially observed in the LRNs, whereas significant levels of IL-4 and IFN-γ was produced in both tissues 14 days after infection. In comparison, IFN-γ was the predominate cytokine, produce at 14 days coinciding with pulmonary inflammation. Suggesting that intense activation promoted changes in the resident pulmonary Th2 environment, and possible is a major component of pulmonary inflammatory immune responses. Both CD4+ and CD8= T cells were shown to have a role in modulation of disease severity during mycoplasma disease. Observation of gross pulmonary lesions reveal that mycoplasma infected mice treated with anti-CD8 antibody showed increase clinical signs of disease and pronounced gross pulmonary lesions. Additionally the number of total mononuclear cells increased dramatically in the absence of CD8+ T cells. Thus, CD8+ T cells may have a regulatory role in controlling resident CD4+ T cells that increased 14 days after infection. Chemokine production is known to mediate the recruitment of lymphocytes to enhance the initiation of immunity as well as be responsible for modulating inflammatory responses. We find that mycoplasma increase the number of dendritic cells in the lung 14 days after infection, and stimulated the production of dendritic cell-derived ABCD-1 chemokine. Also, β-chemokine MIP-1α and MIB-1β production was observed during intense immunization as well as during mycoplasma infection. These results provide evidence for a potential mechanism through which changes in resident pulmonary T cell responses occur given the intensity of the immune response generated.Item The Avian Influenza Pandemic and Physicians' Perception of Preparedness(2008-05-01) Oberdorfer, Joseph R.; Cardarelli, Roberto; Felini, Martha; Licciardone, John C.Oberdorfer, Joseph R., The avian influenza pandemic and physicians’ perception of preparedness. Master of Science (Biomedical Sciences) May, 2008, 77 pp., 5 tables, 3 figures, bibliography 84 titles. Prepared physicians may reduce the mortality and morbidity in patients affected during an avian influenza pandemic. However, repeated surveys of preparedness is physicians indicate that physicians are not confident in the preparedness plans. A survey of 86 physicians was performed to test the perception of preparedness. Multivariable regression analysis indicated that predictors of male gender, OR=29.5, 95%CI=1.172-740.541, ability to access the internet, OR=0.4, 95%CI=1.172-740.541, ability to access the internet, OR=0.4, 95%CI=0.250-0.779, patient education efforts, OR=2.9, 95%CI=1.403-6.163, utilization of electronic records, OR=1.1, 95%CI=1.123-3.514, practicing physical manipulation, OR=1.6, 95%CI=1.022-2.432, and knowledge of government plans, OR=0.5, 95%CI=0.250-0.974, predict better physician preparedness, which was defined as an aggregate score of knowledge and capacity to avian influenza pandemic planning. These results suggest an understanding of the relationship of knowledge and capacity is important in developing a better understanding of physician perception of preparedness.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.