Browsing by Subject "Immunology and Infectious Disease"
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Item A Systematic Screen of the Saccharomyces Cerevisiae Deletion Mutant Collection for Novel Genes Required for DNA Damage-Induced Mutagenesis(2008-07-01) Gong, Jinjun; Siede, Wolfram; Sheedlo, Harold; Reeves, RustinA Systematic Screen of the Saccharomyces Cerevisiae Deletion Mutant Collection for Novel Genes required for DNA Damage-Induced Mutagenesis. Jinjun Gong Department of Cell Biology and Genetics, University of North Texas Health Science Center, Fort Worth, TX 76107. Summary. Deoxyribonucleic acid (DNA) damage is common in a cell’s lifetime. DNA can be damaged by endogenous factors such as reactive oxygen species (ROS) or exogenous agents such as ultraviolet (UV) or industrial chemicals. DNA damage will trigger cell responses including cell cycle arrest, transcription activation, DNA repair or apoptosis. In addition to various DNA repair mechanisms including damage reversal, base excision repair, nucleotide excision repair, mismatch repair, homologous recombination and non-homologous end joining, translesion DNA synthesis is an important DNA damage tolerance pathway that can bypass the lesion on template DNA to finish the replication for cell survival but at the risk of potential mutation in the daughter cells. Accumulation of mutation may lead to cancer occurrence. Translesion DNA synthesis components are highly conserved from yeast to humans. Important players in trans-lesion synthesis pathway such as Rev1, Rev3 and Rev7 were first discovered in budding yeast. Saccharomyces cerevisiae. Homologues were found later in human cells. I used the Saccharomyces cerevisiae deletion mutant collection to do a systematic screen to search for novel genes required for DNA damage induced mutagenesis in yeast. After CAN1 forward mutation assay for the systematic screen and reverse mutation assay for further confirmation, two candidate genes SWI6 and DOA4 were detected. Deletion of SWI6 and DOA4 decreases mutagenesis of cells. At the molecular level, Swi6, a transcription cofactor, is involved in mutagenesis by regulating expression of REV7 at the mRNA and protein levels. Rev7 is a regulatory subunit of DNA polymerase zeta, which is essential for DNA damage induced mutagenesis as well as spontaneous mutagenesis. Rev7 is not UV inducible or cell cycle regulated. The regulation of Rev7 at the transcriptional level by Swi6 is essential. Future experimental approaches are planned to address the mechanism by which DOA4 is involved in mutagenesis.Item An Economic Analysis of Texas' Measles Vaccination Program: 1990-1996(2000-08-01) MacDonald, Tammy O.; Claudia S. CogginIn order to get the most benefit out of limited resources, public health departments must examine the costs and benefits of their activities to determine the most cost-effective method to allocate these scarce resources. The use of economic analysis can inform and help clarify upon which decisions are to be made. (CDC, 1996). The resources used to produce most goods and services in society are efficiently allocated through markets. However, markets can fail to efficiently provide goods and services that largely benefit individuals other than the consumer. The types of goods and services that public health departments provide often fall into that category. Cost-benefit analysis is one type of economic decision-making tool used when market forces are not in control Cost-benefit analysis (CBA) places a dollar value on the costs and benefits of each outcome so they can be compared. This type of economic analysis can then be taken one step further. An incremental or marginal analysis can determine changes in the relative costs and benefits’ resulting from increase or decreases in the amount of resources used in a program. Such an analysis should be part of the decision making process, so that scarce resources can be used efficiently. This paper examines not only the costs and benefits of the measles immunization program in Texas but also, the expansion of the program in the 1990’s. The most significant changes in Texas’ immunization program took place in 1994 as a result of the measles outbreak of 1989-1990. The years 1992, 1993, 1994 and 1996 were chosen for this analysis because of the difference in immunization rates, incidence rates and the level of State funding. This time period represents the most dramatic changes to these three areas. Since the measles vaccination was put into use in 1963, the number of measles cases in the United States has decreased dramatically. An average of 450 measles-associated deaths was reported each year between 1953 and 1963. (TDH, unpublished). Widespread use of the vaccine has led to a 95% reduction in measles compared with the pre-vaccine era. (TDH, unpublished). However, during 1989-1990, the number of measles cases and deaths rose sharply. During 1989, more than 18,000 cases and 41 deaths were reported. The largest number of reported cases since 1978 and the largest number of deaths in two decades in the U.S. (National Vaccine Advisory Committee, 1991). The major cause of the epidemic of 1989 and 1990 was a low vaccination rate among preschool children. (TDH, unpublished). The Centers for Disease Control and Prevention (CDC) estimates national measles vaccine coverage for 2-year-olds in 1985 was 61%, compared with 82% in 1991 and 1992. (CDC, 1994). The CDC has set a goal of 90% of 2-year-olds to be immunized against measles, mumps and rubella. Texas reported 11% of all measles cases in the U.S. between 1989 and 1990, although it only accounted for 7% of the total U.S. population (Schulte et al. 1996). This is likely due to the fact that immunization rates were low throughout the state. In 1989, only 66% of the children in Dallas and 58% in Houston were estimated to be immunized against polio, diphtheria, pertussis, tetanus, measles, mumps, and rubella by the age of two. Nationally, immunization rates were estimated to be 70% at the same time (Schulte et al., 1996). This paper will proceed as follows. Two benefit/cost studies will be outlined in the background section. These studies compare the total benefits and costs of current vaccination programs to no vaccination program. Then a history of Texas’ measles vaccination program will be discussed. It will explain how the measles outbreak of 1989-1990 brought about organizational and financial changes to the immunization program within the Texas Department of Health (TDH). In the method section, the disease costs and costs associated with a vaccination program are used to calculate a benefit/cost ratio. The changes in immunization rates and the associated marginal costs and benefits are then compared. The results of the CBA and marginal analysis indicate that the benefit to cost (B/C) ratios range from 17 to 30:1. After reaching an immunization rate of about 81%, marginal benefits become smaller and smaller while the cost of increasing the immunization rate rises. Finally, the results will be discussed and conclusions made as to the efficiency of Texas’ measles vaccination program. There is some evidence that the CDC’s goal to immunize 90% of 2-year-old children for measles may not the most efficient goal for Texas.Item Astrocyte Elevated Gene-1, a Novel Modulator of Astrocyte Function: Implications for neuroAIDS, aging and glioblastoma(2013-12-01) Vartak, Neha; Ghorpade, AnujaVartak-Sharma, Neha N., Astrocyte elevated gene-1, a novel modulator of astrocyte function: Implications for NeuroAIDS, aging and glioblastoma. Doctor of Philosophy (Biomedical Sciences), Nov, 2013, 180 pp., 1 table, 40 illustrations, 336 bibliographies. Recent attempts to analyze human immunodeficiency virus (HIV)-1-induced gene expression changes in astrocyte identified a multifunctional oncogene, astrocyte elevated gene-1 (AEG-1), as an HIV-1 and tumor necrosis factor-inducible transcript. Subsequently, due to its homology to mouse breast cancer metastasis protein, metadherin, AEG-1 was largely implicated in carcinogenesis of diverse cancer types. However, the role of AEG-1 in astrocytes, the original cell type in which AEG-1 was first identified, still remains to be investigated. In the present study, we identified AEG-1 as a novel modulator of astrocyte function during reactive astrogliosis, neuroinflammation and neurodegeneration, and elucidated its implications in NeuroAIDS, aging and cancer. Our in vitro and in vivo studies recognized AEG-1 modulation of astrocyte migration and proliferation towards the wound site, thereby regulating astrocyte wound healing, a fundamental homeostatic function of astrocytes. Further, AEG-1 expression analyses in HIV-1+ and HIV-1 encephalitic human brain tissues provided the necessary physiological evidence for AEG-1 induction upon HIV-1 neuroinvasion. Herein, we identified AEG-1 as an inflammatory response gene and as an important upstream regulator of NF-κB signaling in astrocytes. Our results demonstrated AEG-1 cytoplasmic and nuclear interaction with NF-κB p65 subunit, which was crucial for NF-κB nuclear translocation, thereby regulating astrocyte neuroinflammation. In the same study, we also identified AEG-1 as a novel regulator of astrocyte glutamate clearance, an important determinant of neurocognitive CNS function, by modulating the expression of the key glutamate transporter, excitatory amino acid transporter 2. Analyses of AEG-1 expression in the cognitive centers of the brain of aging individuals demonstrated AEG-1 age-dependent expression in the human brain, which further proposed a role for AEG-1 in cellular oxidative stress responses. Herein, we identified a novel antioxidant cytoprotective role of AEG-1 in astrocytes and astrocytoma cells. Cellular localization studies by confocal microscopy revealed AEG-1 localization to the dense fibrillar components of the nucleolus in response to injury or oxidative stress, suggesting AEG-1 implication in ribosomal RNA processing. Our results demonstrated AEG-1 regulation of catalase activation and Nrf2 stabilization in response to oxidative stress and further elucidated AEG-1 modulation of Nrf2 nuclear translocation, the first step in antioxidant cellular defense mechanisms. The results presented in this thesis provide insight into the role of oncogene AEG-1 in human astrocytes and ameliorates our understanding of astrocyte-mediated processes in normal and disease-relevant pathologies, ranging from HIV-1-associated neurocognitive disorders and traumatic CNS injuries to primary neoplasms of the brain.Item Brain Derived Neurotrophic Factor Regulates Müller Cell Survival via MAPK and PI3K Pathways(2003-05-01) Taylor, Sara A.; Agarwal, Neeraj; Wordinger, Robert J.; Pang, Iok-HouTaylor, Sara A., Brain Derived Neurotrophic Factor Regulates Müller Cell Survival via MAPK and PI3K Pathways. Master of Science (Biomedical Sciences), January, 2003, 112 pp., 4 tables, 39 illustrations, bibliography, 68 titles. Purpose: Glutamate has been implicated in many pathologies affecting the Central Nervous System including those in the retina, but the exact nature of the role of glutamate in neuronal degeneration remains unclear. In the retina. Müller cells are resistant to glutamate insults that are normally toxic to other cells of the retina, however the molecular and biochemical mechanisms that control their death or survival are not well understood. We used a series of pharmacological inhibitors and molecular biology agents on cultured Müller cells to dissect two key signaling pathways normally involved in cell survival, the Mitogen Activated Protein Kinase – Extracellularly Regulated Kinase (MAPK(ERK) pathway and the Phosphatidylinositide 3 Kinase (PI3K) pathway. Since preliminary data in our laboratory showed that Müller cells upregulate their secretion of neurotrophins including Brain Derived Growth Factor (BDNF) in response to glutamate treatment, we also examined the effect of BDNF on the activation of these two signaling pathways. Methods: Early passaged Müller cells were treated with various concentrations (5 nM -50 μM) of inhibitions of the MAPK(ERK) pathway (GW5074, U0126, and PD98059) or with various concentrations (1-50 μM) of inhibitors of the PI3K pathway (LY294002 or Akt inhibitor) in the presence and absence of 50 ng/ml of BDNF for 24 hours. These experiments were repeated in Müller cells transfected with either NFκB or Bc12 DNA. Cell cultures were then analyzed for surviving cells with an MTS/PMS assay, a colorametric method for determining the number of viable cells in a proliferation assay. Results: The MAPK (ERK) inhibitors PD98059 and GW5074 both resulted in decrease in Müller cell survival. PD98059 did not decrease Müller cell survival until concentrations were high enough to suppress ERK2 phosphorylation. Müller cells transfected with NFκB or Bc12 DNA were able to resist treatment with concentrations of PD98059 that reduced cell number in untransfected cells. The PI3K inhibitor LY294002 also resulted in significant decreases in Müller cell survival in both untransfected cells and cells transfected with NFκB or Bc12 DNA. Treatment with an inhibitor farther down in the PI3K pathway, Akt inhibitor, did not significantly decrease Müller cell survival. Finally, BDNF was not able to increase cell survival in Müller cells treated with PD98059 or U0126, although it did increase the survival of cells treated wit GW5074. BDNF was also able to reverse the decrease in cell survival caused by LY294002 in both untransfected Müller cells or Müller cells transfected with NFκB or Bc12 DNA. Conclusions: Our data shows that Mitogen Activated Protein Kinase – Extracellularly Regulated Kinase (MAPK(ERK) and Phosphatidylinositide 3 Kinase (PI3K) are both essential for Müller cell survival. There is modulation between the pathways and they may interconnected far upstream at a protein previously associated with only the MAPK(ERK) pathway. These results are consistent with a role for both pathways in Müller cell survival.Item Cellular Mechanisms in the Ocular Actions of Endothelin(1996-12-01) White, Karen A.; Yorio, Thomas; Pang, Iok-Hou; Dobbs, RichardWhite, Karen A., Cellular Mechanisms in the Ocular Actions of Endothelin. Doctor of Philosophy (Biomedical Sciences/Pharmacology), December, 1996, 151 pp., 25 tables, 23 figures, references, 111 titles. Endothelins are a family of regulatory peptides which could have important implications in this regulation of aqueous humor outflow and intraocular pressure (IOP). The objectives of this dissertation were to investigate the cellular mechanism of endothelin (ET) receptor interactions in ocular tissues focusing on their effect on second messengers such as phospholipase C (PLC) and calcium, and their interactions with phospholipase A2 (PLA2) in ciliary muscle cells. The hypothesis was that in human ciliary muscle (HCM) cells, endothelin-1 (ET-1), via the ETA receptor and a pertussis toxin sensitive G-protein, activates PLC, which in turn stimulates calcium mobilization. Independent of this pathway, ET-1 also activates PLA2 and increases the release of prostaglandins. These two pathways provide a cellular second messenger balance that influences ciliary smooth muscle contraction. The current study demonstrated that ET-1 and endothelin-2 (ET-2) stimulate calcium mobilization in HCM cells via an ETA receptor subtype. It appears that the increase in intracellular calcium ([Ca2+]i) is the result of ET coupled to PLC via a pertussis toxin sensitive G-protein. A biphasic calcium response is elicited with ET stimulation consisting of a transient increase in [Ca2+]I which appears to be primarily due to release of intracellular stores, followed by a lower sustained phase which appears to be dependent on the influx of extracellular calcium. Endothelin-1 also appears to stimulate an increase in prostaglandin E2 (PGE2) formation through activation of PLA2. Furthermore, it appears that the effects of ET-1 on PLC and calcium are independent of the ET-1 effects on PGE2 production, such that the ET-1 induced increase in [Ca2+]I are coupled to the PLC signaling pathway, whereas increase in PGE2 production appears to be the result of an ETA receptor coupled PLA2. Whether there are different subtypes of ETA receptors or the receptor is coupled through different G-proteins is uncertain. Endothelin-1 and Big ET-1 immunoreactivity was also observed in both HCM and human nonpigmented ciliary epithelial (HNPE) cells. This is the first time that ET-1 and Big ET-1 immunoreactivity has been detected in the HCM cells, suggesting that these cells have the capability to synthesize both peptides. Furthermore, the increase in ET-1 and Big ET-1 immunoreactivity upon stimulation with TNF-α suggests that cytokines may be important regulators of ET synthesis and release. The findings of this research aid in the understanding of the mechanism of action whereby ETs regulate aqueous humor dynamics and IOP. Through a better understanding of the cellular actions of ET, insight is gained into the development of new ocular selective agents acting at the ET receptor.Item Characterization of a Novel Receptor CS1 in Human Lymphocytes; Studies in Natural Killer Cells and B-Lymphocytes(2005-06-01) Lee, Jae Kyung; Porunelloor Mathew; Ming-Chi Wu; Hriday DasThe purpose of this study was to investigate the roles of CS1 on human lymphocytes. The molecular and functional characterization of CS1 receptor in the natural killer (NK) cells and B lymphocytes was investigated. CS1 (CRACC, novel Ly9) is a novel member of the CD2 family receptor expressed on natural killer (NK), T cells, activated Bcells and dendritic cells. To examine the existence of isoform of CS1, library from NK cells was screened based on wild type of CS1 (CS1-L). A splice variant form of CS1 (CS1-S), which lacks immunoreceptor tyrosine-based switch motifs (ITSMs) in cytoplasmic domain, was identified. To demonstrate the function of CS1 on human NK cells, transfectants that stably express each isoform were generated. CS1-L was able to mediate redirect cytotoxicity of P815 target cells as well as intracellular calcium influx in the presence of monoclonal antibody against CS1 suggesting that CS1-L is an activating receptor. CS1-S showed no effect on the cytolytic function and calcium influx suggesting that CS1-L and CS1-S may differentially regulate human NK cell functions. Although CS1 was also cloned from cDNA library of human B-lymphocytes as well as of NK cells, very little is known regarding its biology on human B-lymphocytes. Here I investigated the expressions and functions of CS1 in human B cells. Human B cells expresses only CS1-L isoform and the levels of CS1 expression are upregulated after activation in vitro. Importantly, monoclonal antibody of CS1 (1G10 mAb) strongly enhances proliferation of both freshly isolated and activated B cells. The enhanced proliferation effects of CS1 were most prominent on B cells activated by anti-CD40 mAbs and/or IL-4. Human cytokine microarray results indicated CS1 enhanced mRNA transcripts of fms-line tyrosine kinase 3 ligand, lymphotoxin A, tumor necrosis factor, and IL-14 which are related with mostly growth promoting activity. These results suggest that autorine cytokines might be the mediators for the function of CS1 on B cell in which it can induce proliferation of activated B cells. This study suggests that CS1 plays important role in human NK cells and B-lymphocytes.Item Characterization of MRSA Infection at Childrens Medical Center, Dallas, January 2005-June 2005(2006-05-01) Okoro, Ngozi M.; Raghbir Sandhu; Claudia S. Coggin; Sejong BaeOkoro, Ngozi M., Characterization of MRSA infection at Childrens Medical Center, Dallas, January 2005-June 2005. Master of Public Health (Epidemiology), May 2006, 33p., 14 tables, 10 illustrations, bibliography, 13 titles. MRSA infection is increasingly emerging in patients without the established risk factors hence the term CAMRSA. This study is a descriptive secondary data analysis from an ongoing study at UTSM/CMCD and describes the CMCD patients with MRSA infection. Data analysis showed a consistent increase in the incidence rate of the infection with slight female preponderance. Race distribution showed that blacks were the majority. Most children were less than 2years, used Medicaid, had superficial infections and community-acquired infections. All (100%) isolates were susceptible to Vancomycin and Linezolid while many (92.2%) were resistant to Erythromycin. The increasing incidence in CAMRSA infection remains a challenge for public health professionals and the resistant pattern a potential problem to the pharmaceuticals.Item Chemokine CXCL8 Mediated Intercellular Interactions in HIV-1 associated Dementia(2013-12-01) Mamik, Manmeet K.; Ghorpade, AnujaThis dissertation explores the role of chemokine CXCL8 during human immune deficiency virus (HIV)-1 infection in the brain. Chemokine CXCL8 is an important neutrophil chemoattractant implicated in various neurodegenerative disorders. It is upregulated in the brains and cerebrospinal fluid of HIV-1 infected individuals suggesting its potential role in HIV-1 associated neuroinflammation. Astrocytes are known to be the major contributors to the CXCL8 pool. Interleukin (IL)-1β activated astrocytes exhibit significant upregulation of CXCL8. In order to determine the signaling pathways involved in CXCL8 regulation in astrocytes, we employed pharmacological inhibitors for non-receptor Src homology-2 domain-containing protein tyrosine phosphatase (SHP) 2 and mitogen-activated protein kinases (MAPK) pathway and observed reduced expression of CXCL8 following IL-1β stimulation. Thus, our findings suggest an important role for SHP2 in CXCL8 expression in astrocytes during inflammation, as SHP2, directly or indirectly, modulates p38 and extracellular signal regulated kinase (ERK) MAPK in the signaling cascade leading to CXCL8 production. In the post-antiretroviral therapy (ART) era, low level of productive replication of HIV-1 in brain is a critical component of neuropathogenesis regulation. HIV-1 replication is a complex mechanism involving both host and viral factors. The majority of viral replication in brain occurs in perivascular macrophages and/or 2 microglia. In this study, we investigated the effect of CXCL8 on productive infection of HIV-1 in human monocytes-derived macrophages (MDM) and primary human microglia. The results show that CXCL8 mediates productive infection of HIV-1 in MDM and microglia via receptors CXCR1 and CXCR2 and induces HIV-1 long terminal repeat (LTR) promoter activity. Detailed understanding of astrocyte signaling and HIV-1 replication, as presented in the thesis, will be relevant to glial-neuronal interactions, which are central to neuroinflammation in HIV-1 and many other neurodegenerative conditions. Also, modulation of levels of CXCL8 can be a therapeutic strategy for control of productive HIV-1 replication in the brain.Item Effects of Serine Protease-Like F (SPLF) on Alpha-Toxin Expression in Staphylococcus aureus(2003-05-01) Pulse, Mark E.; Mart Hart; Jerry Simecka; Ming-Chi WuPulse, Mark E., Effects of Serine protease-like F (Sp1F) on Alpha-Toxin Expression in Staphylococcus aureus. Master’s of Science (Microbiology). May 2003. Pages-67. Table-5. Figures-9. Transposon mutagenesis (Tn551) was used to generate agr-suppressor mutations in the agr-null Staphylococcus aureus strain RN6911 (Δagr;;tmn). Firty-four suppressor mutants displaying changes in hemolysin, protease, and lipase activities were isolated, and only twenty-six mutants contained Tn551 within their chromosomes. Transposon insertion sites for seven mutants were determined by sequencing amplicons generated by arbitrary-PCR. One of the insertion sites was within the serine protease-like F (spʅF) gene. Alpha-toxin message levels for the spʅF mutant were similar to RN6911. However, alpha-toxin activity in spent media isolated from the spʅF mutant were similar to RN6911. However, alpha-toxin activity in spent media isolated from the spʅF mutant was increased ten-fold as compared to RN6911. Transduction of the spʅf:Tn551 mutation back into the parental strain verified the link between the phenotype and the mutation. Whole cell lysates from Escherichia coli cells containing a plasmid copy of spʅF displayed protease activity on casein. These data suggest that SpʅF may be post-translationally modifying alpha-toxin through proteolysis.Item Efficacy of Alcohol-Impregnated Port Protectors on Central Line - Associated Blood Stream Infections in Intensive Care Units(2013-12-01) Omiwade, Oluwatoke; Shi, XiangrongOmiwade, Oluwatoke., Efficacy of Alcohol-Impregnated Port Protectors on Central Line- Associated Blood Stream Infections in Intensive Care Units. Master of Science (Clinical Research Management), May, 2014, 52pp, 8 tables and 23 references. This research project focused on assessing the effectiveness of alcohol-impregnated port protectors (A-IPP) in reducing infection rate among the patients having central venous catheters in selected intensive care units. Infection rate data was obtained from the department of Infection Control at Baylor All Saints Hospital at Fort Worth. A comparison was made between the infection rates before and after the use of A-IPP. Overall, the risk of infection is extremely low ([less than] 1%). The newly implemented alcohol impregnated protectors do not significantly affect observed infection rates in the units investigated.Item Epidemiologic Assessment of a Targeted Tuberulosis Screening and Treatment Program Based on Geographic and Molecular Clustering(2005-08-01) Moonan, Patrick KevinMoonan, Patrick K., Epidemiologic Assessment of a Targeted Tuberculosis Screening and Treatment Program Based on Geographic and Molecular Clustering. Doctor of Public Health (Disease Prevention and Control), August 2005, 93 pp., 12 tables, 7 illustrations, bibliography, 148 tables. One of the primary goals of the tuberculosis elimination strategy is to interrupt the transmission of mycobacterium tuberculosis (TB). The most effective way to accomplish this goal is to identify and treat individuals who have active tuberculosis. However, even in highly effected tuberculosis control programs, M. tuberculosis continues to be transmitted to others, largely because most transmission occurs before diagnosis and initiation of therapy. Under the current recommendations, testing should be targeted at specific high-risk populations. While a strategy of targeted testing and treatment of persons most likely to develop tuberculosis is attractive, it is uncertain how best to accomplish this goal. This is the first study to assess the use of geographic and molecular surveillance in guiding a targeted tuberculosis screening and treatment of active tuberculosis and latent tuberculosis infection that monitors potential transmission in a defined high risk geographic area. The results of this geographically targeted program demonstrate significant yield for discovering active cases, latent tuberculosis infection, and recent transmission (TST converters). In this setting, geographically targeted screening identified as many as 19.8 tuberculosis cases per 1,000 persons screened and as many as 292.4 latent tuberculosis infections per 1,000 persons screened. Additionally, successful treatment of these individuals reduced the number of both cases and latent infection identified. Over a three-year period the case detection rate, latent infection detection rate, and TST conversion rate was reduced by 335%, 171% and 285% respectively.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 For Better or for Worse: The Influence of NK Cells, IFN-y and IL-4 on the Development of Protective Adaptive Immunity in Mycoplasma Respiratory Disease(2008-08-01) Bodhankar, Sheetal; Porunelloor A. Mathew; Stephen R. Grant; Rance E. BergSheetal Bodhankar, For better or for worse: The influence of NK cells, IFN-y and IL-4 on the generation of protective adaptive immunity in mycoplasma respiratory disease, Doctor of Philosophy (Microbiology and Immunology) August 2008, 136 pp., 13 illustrations, 3 tables, bibliography, 176 titles. The purpose of these studies was to evaluate the contribution of NK cells and the polarizing cytokines, IFN-y and IL-4, in the generation of protective adaptive immunity against mycoplasma infection. Presence of NK cells during the generation of adaptive immunity resulted in detrimental immune responses. However, upon depletion of NK cells, prior to nasal-pulmonary immunizations, mice demonstrated better clearance of mycoplasma from the respiratory tracts. That the NK cells hindered with the beneficial development of adaptive immune responses via lymphoid cells was demonstrated, since no protection was demonstrated in SCID mice. Furthermore, purified pulmonary T and B lymphocytes primed in a NK cell depleted environment as opposed to one’s primed in a versus non-depleted environment could transfer protection to naïve mice. Interestingly, this is the first time that a favorable role of functional CD4 T cells in mediating protection in mycoplasma respiratory disease was demonstrated. The presence of NK cells at the time of nasal-pulmonary immunization also modulated mycoplasma-specific IFN-y and IL-4 responses in lungs and lower respiratory nodes. In evaluating the roles of IFN-y and IL-4, it was demonstrated that the absence of a single cytokine alters a vast array of chemokines and cytokines produced in response to mycoplasma infection. Corresponding to the higher numbers of mycoplasma and severity in disease due to the loss of IFN-y, altered cytokine and chemokine responses in the lungs to mycoplasma infection were demonstrated. Nasal-pulmonary immunization of IFN-y mice exacerbated, rather than reduced, mycoplasma disease and infection, whereas immunization of IL-4 mice significantly enhanced protection along the respiratory tract particularly in the lungs. Prominent Th-2 type immune responses in the lungs of IFN-y mice corresponded to the severe immunopathologic reactions developed after mycoplasma infection and immunization. These studies demonstrated diverse but crucial functions for NK cells, IFN-y and IL-4 vital towards the development of protective adaptive immune responses against mycoplasma respiratory infection that will have a significant impact on future studies on respiratory immunology.Item Geospatial and Molecular Clustering of Mycobacterium tuberculosis, Tarrant County, TX, 1993-2000(2002-05-01) Moonan, Patrick Kevin; Manuel Bayona; Teresa N. Quituga; Joseph OppongMolecularly clustered cases are assumed to be the result of recent transmission of those in the cluster. An intervention that targets clustered cases with recent transmission, such as identifying contacts of active cases, could be effective as a programmatic control measure. The purpose of this study is to identify areas of recent transmission, whereby determining the contribution of geospatial and molecular clustering to the local tuberculosis morbidity. Tuberculosis cases due to recent transmission have important implications for tuberculosis control programs. They suggest that current methods of case-finding, investigations of susceptible contacts, and the provision of preventive therapy are ineffective in interrupting some transmission. This study utilized molecular strain characteristics and GIS technology to uncover geographical links to on-going transmission, where tradition public health surveillance methods are failing. Risk behaviors such as illicit drug use, crack-cocaine use, jail experience, and sexual relations with a prostitute were strongly associated with on-going transmission. Place factors, specifically where patients reside, was also found to be significantly associated for certain zip codes in Tarrant County. Cases in urban zip codes 76102 [OR=3.954; 95% CI=1.803, 8.671] and 76105 [OR=3.135; CI=1.254, 7.835] were strongly associated to infection with a clustered strain when compared to the rest of the county. The use of Geographical Informational Systems (GIS) technology and molecular strain typing provides a proactive approach that may be used to initiate traditional surveillance investigations. As an application utility, this project will be used to develop more effective means of tuberculosis control within Tarrant County.Item Immediate Effects of Osteopathic Manipulative Treatments on Immune Function in a Healthy Population: A Pilot Study(2006-05-01) John, Janice Thomas; Scott Stoll; Jerry Simecka; Barbara AtkinsonJanice Thomas, D.O., M.S. Immediate Effects of Osteopathic Manipulative Treatments on Immune Function in a Healthy Population: A Pilot Study. Master of Science (Clinical Research and Education – OMM), May 2006, 75 pp, 3 tables, 5 figures, 66 references, 24 titles. Objectives: The purpose of this pilot study was to investigate the immediate effects of Osteopathic Manipulative Treatment (OMT) on immune function in a healthy population. Methods: This was a randomized, blinded and controlled clinical trial. 50 healthy individuals, ages 18 to 40, were recruited. Subjects were randomly assigned to one of two groups: OMT or Rest (control). Blood and saliva samples were collected pre and post-intervention (thirty minutes of OMT or Rest). Samples were analyzed for a CBC, salivary IgA, and various lymphocyte populations. Results: This study successfully demonstrated the feasibility of this protocol. No statistically significant differences in outcome measures were identified between the two groups, nor were any apparent trends identified. Conclusion: This study established a framework for future research investigating the effects OMT on acute and chronic infection, chronic pain, and immunocompromised populations in human and/or animal populations.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 "Is it as Simple as ABC?" -- Applying Uganda's ABC Approach Amongst the Dinka Ethnic Group of Southern Sudan(2007-12-01) Madut, Nyebol B.; Peter Hilsenrath; Karan Singh; Jim StimpsonMadut, Nyebol B., “Is it as simple as ABC? – Applying Uganda’s ABC approach amongst the Dinka ethnic group of Southern Sudan. Master of Public Health (Health Management and Policy), December 2007, 127 pp, 23 figures, 23 tables, bibliography, 157 titles. The purpose of this thesis is to explore those activities than can potentially result in a constructive balance of A, B and C activities, which could translate into an effective HIV prevention strategy for Southern Sudan’s largest ethnic group, the Dinka. In other words, the objective of this paper is to examine the local cultural context of southern Sudan’s largest ethnic group, as well as the state of the AIDS epidemic in areas populated by the Dinka; and then determine which public health and/or health management and policy strategies will prove to be the most effective in tailoring an appropriate mix of ABC activities.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 Molecular Basis for 2B4-CD48 Interactions(2001-08-01) Huynh, Van T.; Mathew, Porunelloor A.; Goldfarb, Ronald; Das, HridayHuynh, Van T., Molecular Basis for 2B4-CD48 Interactions. Master of Science, Molecular Biology and Immunology, August 2001, 93 pp., 3 tables, 19 illustrations, bibliography, 51 titles. Natural killer cells are lymphocytes that play a role against cancer and viral infections. 2B4 is a membrane glycoprotein expressed on natural killer cells. In the present study we characterized 2B4 from mice strains BALB/c, 129/svj and A.CA. Nucleotide and peptide analysis revealed that polymorphyic residues in 2B4 are located in the variable domain. My second project was to determine the amino acids involved in the binding between 2B4 and CD48. Twelve mutations were made in human 2B4 to disrupt their interaction. In the last part of the study, an attempt has been made to elucidate the role of tyrosine and threonine amino acids found in the novel tyrosine motifs (TxYxxI/V) that reside in the cytoplasmic domain.Item Molecular Basis of Cancer Cell Recognition and Killing by Human Natural Killer Cells(2001-05-01) Boles, Kent S.; Bennett, Michale; Leudtke, Robert; Goldfarb, RonaldNatural Killer (NK) cells are a population of lymphocytes vital for the innate immune response. These cells protect the host during the early phase of infection before the adaptive immune response is effective. NK cells are direct effectors via cytoxicity towards neoplastic and infected cells. Additionally, they modulate the immune response by the production of cytokines, most notably interferon y and tumor necrosis factor a. Furthermore, NK cell receptors do not undergo rearrangement. Repetoires of activating and inhibitory receptors regulate the function of NK cells via a balance of signaling. NK cell receptors can broadly be divided by their ligand specificity as well. Most of the known receptors recognize MHC class I molecules and transduce inhibitory signals. This is the basis for the missing self hypothesis espoused by Karre and colleagues. The LY49 molecules server this function in the mouse and are related to the C-type lectins. In primates, a family of killer inhibitory receptors (KIR) appear to play the same role and are in the immunoglobulin (Ig) superfamily of receptors. Whether humans expressed the Ly49 receptors was a fundamental question in NK cell biology. In my attempt to address this issue, I isolated two receptors related to the C-type lectin receptors and localized to the human NK gene complex on chromosome 12 in a region syntenic to where the murine Ly49 genes reside. Functional characterization of these receptors will facilitate our understanding of NK cell biology. Additional activating receptors include the members of the CD2 subset of the immunoglobulin superfamily molecules expressed on NK cells and other leukocytes, including murine 2B4. 2B4 is the high affinity ligand for CD48. Engagement of 2B4 on NK cell surfaces with specific antibodies or CD 48 can trigger cell mediated cytotoxicity, IFN-y secretion, phosphoinositol turnover and NK cell invasiveness. This work describes the isolation and characterization of the human homologue of the 2B4 receptor. The putative peptide has a type I structure with one transmembrane domain. The extracellular region is comprised of two immunoglobulin like domains with six putative N-linked glycosylation sites. The cytoplasmic domain of 2B4 contains unique tyrosine motifs (TxYxxV/I) that associate with src homology 2 domain containing protein (SH2DIA) or signaling lymphocyte activation molecule (SLAM)-associate protein (SAP), whose mutation is the underlying genetic defect in the X-linked lymphoproliferative disease (XLPD). Impaired signaling via 2B4 and SLAM is implicated in the immunopathogenesis of XLPD. CS1 is a novel member of the CD2 subset that contains two of the unique tyrosine motifs present in 2B4 and SLAM. Signaling through 2B4, CS1 and other members of the CD2 subset may play a major role in the regulation of NK cells and other leukocyte functions.