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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

GENE THERAPY OF SYSTEMIC LUPUS ERYTHEMATOSUS IN NZB/W F1 MICE

Ye, Xiaojing 23 March 2005 (has links)
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by polyclonal B-cell activation, autoantibody production and immune complex-mediated glomerulonephritis (GN). NZB/W F1 mice spontaneously develop SLE-like symptoms and have been widely used as an animal model for SLE. Even though the etiologic cause of autoimmunity in both human and murine lupus is not clearly understood, mounting evidence indicates the involvement of autoreactive B cells and T cells. Blockade of costimulatory pathways using CTLA4Ig fusion protein and anti-CD40 ligand monoclonal antibody (mAb) has been able to suppress autoantibody production and inhibit lupus nephritis in NZB/W F1 mice. In spite of these successes, protein- or mAb-based therapies are expensive, deliveries are problematic, and bolus injections result in transient and toxic levels of these reagents. In comparison, gene therapy offers an advantageous solution by achieving long-term, stable transgene expression and convenient gene delivery. Among the vectors used in gene therapy, recombinant adeno-associated virus (rAAV) has been proven to be a promising one because of its non-pathogenicity and non-immunogenicity. In this project, the hypothesis that rAAV serotype 8 (rAAV8)-mediated immunomodulator gene transfer was able to prevent and suppress lupus development in NZB/W F1 mice was tested. First, the transgene expression pattern following systemic delivery was studied. rAAV8-mediated gene delivery was able to achieve long-lasting and high-level transgene expression following a single intraperitoneal or intrasplenic injection. Second, rAAV8-mediated costimulatory blockade gene transfer prevented autoantibody production, delayed proteinuria onset, prolonged survival and protected kidneys from immune-complex induced tissue damage. Moreover, it successfully suppressed CD4+ T cell activation and also the transition from naïve to memory T cells. Among all early prevention strategies tested in newborn mice, the combination of murine CTLA4Ig (mCTLA4Ig) and murine CD40Ig (mCD40Ig) was more efficient than both single vectors, suggesting a synergistic effect between these two costimulatory blockades. Surprisingly, the late prevention in young lupus-prone mice achieved results similar to those observed in the early prevention. Furthermore, rAAV-mediated costimulatory blockade gene transfer did not suppress host humoral response to foreign antigens. Finally, in the treatment of lupus mice with high autoantibody titers, mCTLA4Ig alone, or in combination with mCD40Ig, was able to decrease autoantibody titers, delay proteinuria onset, and prolong survival. The therapeutic effects were evidenced to be dose-dependent. In general, this study indicates that rAAV8-mediated costimulatory blockade gene transfer is capable of preventing and suppressing lupus development, thereby suggesting the successful application of this autoimmune disease gene therapy both in research and in clinical settings to promote public health.
62

INVESTIGATION OF THE RELATIONSHIP OF CANDIDATE GENES ON CHROMOSOME 10 WITH THE RISK AND AGE-AT-ONSET OF ALZHEIMERS DISEASE

Ozturk, Ayla 09 June 2005 (has links)
Alzheimers disease (AD), a common debilitating neurodegenerative disease, is a major public health problem in the United States because it affects almost 50% of the people after age 85. Although AD has been described since 1907, no cure or universally accepted effective treatment has been devised. Studying factors that play a role in risk and pathogenesis of LOAD may lead to development of new therapies and give an insight to the etiology of disease. Both genetic and environmental factors have been implicated in the etiology of AD. Twin studies have shown heredity to be a major causal factor in the development of LOAD. Despite the evidence for substantial genetic effect in the etiology of LOAD, the APOE*4 allele in the APOE gene is the only established risk factor in the development of LOAD. However, as the APOE*4 allele is neither necessary nor sufficient for the development of AD, this emphasizes the involvement of other genetic and/or environmental factors, which alone or in combination with APOE*4 can modify the risk of AD. Recently, linkage studies in multiplex families with LOAD have provided evidence for the existence of additional putative genes for AD on several chromosomes, including chromosome 10. A broad linkage peak encompassing >50 cM region between chromosome 10q21 and 10q25 has been implicated that influence both AD risk and age-at-onset (AAO). There are more than 300 genes in this broad genomic region of chromosome 10 and thus task for identifying the chromosome 10 gene is daunting. One approach is to focus on the known candidate genes in the region. There are number of promising candidate genes in this region that are involved in either in the production, processing or clearance of beta amyloid peptide and include choline acetyltransferase (CHAT), plasminogen activator, urinary (PLAU), insulin-degrading enzyme (IDE), hematopoietically expressed homeobox (HHEX), glutathione S-transferase, omega-1 (GSTO1), glutathione S-transferase, omega-2 (GSTO2), and protease, serine, 11 (PRSS11). In this study, we have examined the role of these genes under the linkage peak on chromosome 10 to assess their role with AD risk and AAO. Association studies for 14 markers were performed in a large case-control cohort comprising 1012 white LOAD subjects and 771 white control subjects. No significant associations were observed with any of the polymorphism examined in the IDE, HHEX, GSTO1, GSTO2 and PRSS11 genes. Of the 3 CHAT SNPs examined, we detected both allelic and genotypic association of the intron 9 polymorphism with AD risk. The rare AA genotype appears to confer a modest risk for the development of AD in a recessive fashion (OR: 2.37; p=0.007). In addition, we observed APOE-dependent effect of the CHAT exon 5 polymorphism with AD risk (OR=0.76; p=0.046). Although these associations are modest, they suggest the presence of putative functional variants in the CHAT gene or nearby genes. In the PLAU gene, we examined 3 tagSNPs and found a modest protective effect with one SNP in the 3 UTR (OR=0.71; p=0.02), which was confined to APOE*4 carriers (OR=0.58; p=0.02). In our analysis of the association of the candidate genes with AAO, suggestive association were observed only with the PLAU 3 UTR (p=0.10) and intron 9 (p=0.04) polymorphisms. In summary, our data on a large number of AD cases and controls suggest that genetic variation in two positional candidate genes on chromosome 10 (PLAU and CHAT) may affect the risk and AAO of LOAD.
63

Mechanisms Leading to Chromosomal Instability in Oral Cancer Cells

Reshmi, Shalini C 05 July 2005 (has links)
In the United States, cancer is a leading cause of death, second only to heart disease (MOKDAD et al. 2004). Although it is estimated that in 2005, cancer of the oral cavity will account for only 2.1% of cancer cases and 1.3% of overall cancer deaths in the U. S. (JEMAL et al. 2005), high-risk behaviors such as smoking cigarettes, using smokeless tobacco, and consuming excessive alcohol have been shown to play a major role in OSCC development. Exposure to environmental agents, including tobacco products, alcoholic beverages, and/or viruses, such as human papillomavirus (FORASTIERE et al. 2001; HO and CALIFANO 2004; MORK et al. 2001) have a profound influence on cells within the oral cavity. These factors have been shown to induce genetic alterations including chromosomal alterations, DNA changes, and/or epigenetic alterations, such as changes in DNA methylation that affect genetic regulation. Genetic alterations in cells are useful biological markers that assist in early detection of cancer and response to therapy (SIDRANSKY 1995). Currently, however, there are no useful biomarkers to identify early changes involved in OSCC development. One genetic alteration observed in 45% of OSCC is amplification of chromosomal band, 11q13. This event has been shown to follow dysplastic cellular changes, but occur prior to development of carcinoma in situ (FORASTIERE et al. 2001). Therefore, 11q13 amplification may be a useful biomarker for detecting OSCC. In addition, understanding the molecular mechanisms that promote 11q13 gene amplification may provide valuable information for devising novel prevention measures and therapies. In the current study, we show that the primary mechanism promoting 11q13 gene amplification is BFB cycles. Furthermore, we suggest that breakage at the common fragile site, FRA11F, may be responsible for initiating 11q13 gene amplification. By determining the primary mechanism that leads to 11q13 amplification in OSCC, additional investigations focusing on the biological basis of this process may provide important information for developing successful measures and treatments that will increase the survival rate for individuals afflicted with oral cancer.
64

Telephone Education and Follow-up Improve Adherence to Comprehensive Care in Sickle Cell Disease

Patik, Meredith Suzann 14 June 2005 (has links)
Programs such as routine follow-up phone calls are an important part of public health. These programs are developed as a means to enhance the medical care offered by physicians. It brings many services to the public, making them more accessible for everyone. Integrating outreach programs in order to provide services to help meet the needs of a chronically ill population is of great importance to the field of public health. It is vital for patients with sickle cell disease to adhere to comprehensive care in order to decrease the morbidity and mortality of the disease. Patients who do not adhere to the recommended routine of care set forth by their physicians run the risk of developing serious complications or even death. The Comprehensive Sickle Cell Center at Childrens Hospital of Pittsburgh has established an outreach program that is aimed at increasing attendance to comprehensive care clinic, as well as educating patients and their families about sickle cell disease. All active patients were routinely contacted via phone in order to remind them to schedule an appointment in the clinic and to provide a range of services over the phone, such as prescription refills, answering questions about sickle cell disease, and psychosocial support. The patients were also asked questions about their home care routine so as to follow-up with them. This outreach program has been successful in increasing attendance to comprehensive clinic and in increasing the number of patients who are compliant with annual screenings.
65

Up regulation of caveolin-1 during H2O2 induced oxidative stress

Dasari, Arvind 08 July 2005 (has links)
Caveolae (little caves) are 50 -100 nm invaginations seen on the plasma membrane of most cells. Caveolin-1, the marker protein of caveolae in most tissues, is the structural and functional unit of caveolae. Previous studies have demonstrated the tumor suppressor capability of caveolin-1. Our lab has already shown that expression of caveolin-1 induces premature senescence in cells, possibly including those with malignant potential. We proposed that this might explain the tumor suppressor function of caveolin-1. We have further shown that oxidative stress induces premature senescence through up regulation of caveolin-1. To further elucidate the molecular mechanisms underlying this process, we used H2O2 as a model to generate stress induced premature senescence (SIPS) and examined the response of caveolin-1 promoter under these conditions. Constructs with serially truncated segments of the mouse caveolin-1 gene promoter linked to a luciferase reporter gene were made and luciferase assays were carried out. These experiments demonstrated that the critical regions lay in two segments: -222/-372 and -91/-150 of the promoter region. A consensus Sp1 binding sequence was identified within each deleted segment. Gel shift analysis of protein binding from nuclear extracts to these caveolin promoter DNA sequences confirmed that transcription factors were binding to the Sp1 consensus elements as part of the transcriptional response to H2O2 induced senescence. Further deletion mutagenesis of the individual Sp1 consensus sites confirmed the identity of the transcription factor to be Sp1. These findings suggest that Sp1 mediates oxidant induced up regulation of caveolin-1 expression. In subsequent experiments, we examined the effect of inhibitors of p38 Mitogen activated protein kinase pathway on the levels of caveolin-1 expression during SIPS by western blot and luciferase assay. We found that this pathway plays a direct role in the up regulation of caveolin-1 during SIPS, possibly through modification of Sp1 to increase its activity. Public Health Importance: Cancer is a leading public health concern. Cav-1 has been shown to be a tumor suppressor gene involved in a large number of human tumors. Induction of premature senescence in cells with malignant potential is thought to be a vital tumor suppressor function. Our study aims to define the tumor suppressor capacity of Cav-1 by elucidating the pathway by which it induces premature senescence.
66

The Effect of Diet/Supplement Intake and Competitive Swimming/Gymnastics upon Bone Mineral Density of Collegiate Females

Jones, Teresa Christine 19 November 2001 (has links)
The purpose of this pilot study was to determine if there was a relationship between dietary/supplemental intake and competitive activity (swimming and gymnastics), on the bone mineral density of 18-21 year old females. Five swimmers, 4 gymnasts, and 12 control subjects were recruited from the university student body. All subjects completed a 3-day diet/supplement record, 3-day activity record, past calcium intake form, and a medical history form. Bone mineral density (BMD) was measured for the whole body, L1-L4, the proximal femur and body composition by DEXA. Results indicated the control subjects reported a significantly greater percent of the RDA for energy, protein, and carbohydrate than the athletic groups. There were no differences found for bone building nutrients among the three groups. No correlations could be made between diet/supplement intake and BMD. Gymnasts initiated training at an earlier age than swimmers, and were found to be shorter and experience delayed menarche than other groups. Gymnasts had significantly greater whole body BMD than the control subjects, but not significantly greater than the swimmers. Gymnasts also had greater BMD at all sites measured, and significantly greater than the control subjects at the spine L1-L4, and femoral neck. Gymnasts had significantly greater BMD at the femoral neck and total hip than the swimmers. Though not significant, the swimmers had greater BMD at whole body, and spine L1-L4 than the control subjects. As in similar studies, the greater BMD found in the gymnasts can be attributed to their weight bearing exercise. Due to small sample size, conclusions concerning the benefit of swimming on BMD cannot be made from this study.
67

The Influences of Parenting Styles on Children's Classroom Motivation

Cramer, Kathryn Elizabeth 03 September 2002 (has links)
This study was part of a larger, longitudinal project investigating the relationships between family stress processes and children's development. The purpose of the current study was to examine the relationship between authoritarian, permissive, and authoritative parenting styles and children's classroom motivation as measured by child interviews and teacher perceptions. The population of this study included 281 first and third grade students and their parents in a mid-sized Southern city. Parenting styles data for this study were collected via mailed questionnaires consisting of the Primary Caregivers Practices Report (Robinson et al., 1995) and questions used to obtain demographic information. Motivation data were collected via child interviews using the Self-Report Scale of Intrinsic versus Extrinsic Motivation in the Classroom (Harter, 1981) and the Teacher-Report Scale of Intrinsic versus Extrinsic Motivation in the Classroom (Harter, 1981), which was given to teachers to complete. Correlation analyses were performed to determine which demographic characteristics should be used as control variables. Regression analyses were performed to examine the relationship between parenting styles and children's classroom motivation. In general, the results of the current study did not support the researcher's expectations that the authoritative parenting style would be positively related to children's intrinsic motivation, and authoritarian and permissive parenting styles would be negatively related to children's intrinsic motivation. The results were inconclusive. As expected by the researcher, mothers' authoritative parenting was found to be positively related to first graders' mastery motivation, fathers' authoritarian parenting was found to be negatively related to first graders' mastery motivation, and mothers' permissive parenting was negatively related to teachers' perceptions of children's classroom motivation. Contrary to the researcher's expectations, fathers' authoritarian parenting was found to be positively related to third graders' mastery motivation and teachers' perceptions of children's classroom motivation.
68

The Effect of Resource Cycling and Food Insecurity on Dietary Intake and Weight of Low-Income, Single Mothers Living in Rural Louisiana

Smith, Jennifer 26 April 2002 (has links)
Food security, nutritional adequacy, and anthropometrics were assessed in 30 low-income women living in rural Louisiana. For food stamp recipients, a 24-hour-diet recall was collected at the beginning (Day 1) and another at the end (Day 2) of their monthly resource cycle; for non-food stamp recipients, the first 24-hour diet recall was collected at a time that was specified by participants (Day 1) and the second was collected approximately 31/2 weeks later. Twenty-one of the 30 participants received food stamps. Ten of the 30 participants were food insecure. Of the 10 food insecure participants, seven received foods stamps. As a whole, participants were overweight. Irrespective of grouping, participants diets were similar and poor. Many participants did not consume at least 67% of the Recommended Daily Allowances (RDA) or Dietary Reference Intakes (DRI) for energy; calcium; iron; zinc; folate; and vitamins A, D, E, and C. Participants were more likely to meet at least 67% of the RDA or DRI for protein; vitamins B6 and B12; niacin; thiamin; and riboflavin. With the exception of the fats/sweets group, participants also failed in meeting the Food Guide Pyramid recommendations. Between 30% and 50% of the entire population exceeded the National Cholesterol Education Program recommendations for total fat, saturated fat, and cholesterol. The number of eating episodes and number of different foods consumed was also low. Food insecure participants had a significantly higher weight (p=0.0079), body mass index (p=0.0135), and percent body fat (p=0.0298) than food secure participants. A significant difference was found between Day 1 and Day 2 for mean differences in energy (p=0.0367), saturated fat (p=0.0178), and monounsaturated fat (p=0.0324) for food stamp recipients and non food stamp recipients. There was a significant difference between Day 1 and Day 2 in the mean number of servings of fats and sweets consumed for the entire population (p=0.0183). Participants were unable to define a balanced meal. Inadequate nutrient intake increases the risk of developing a nutrition-related disease. Nutrition education programs could benefit participants in making better food choices
69

Does Achieving Social Policy Goals Insure Positive Outcomes: From Welfare Reliance to Wage Work in Rural Louisiana

Blalock, Lydia Bentin 13 June 2002 (has links)
This research was Wave II of a longitudinal, qualitative study designed to describe the outcomes of welfare reform legislation on rural families in Louisiana as they tried to comply with provisions of the Personal Responsibility and Work Opportunity Reconciliation Act of 1996. This particular study looked at a subset of women (n=12) from Wave II and explored two questions: (a) Whether the decline in Louisiana welfare caseloads translated into rural women finding and keeping jobs; and (b) What is the likelihood that the women employed at the time of this study will be able to sustain their work efforts and realize self-sufficiency. Human ecology, rational choice, and behavioral change theories guided this research. Whether women adapt to changed societal expectations and successfully transition from welfare dependence to self-sufficiency is dependent upon the women's micro and macro-environments and whether they can make a second-order behavioral change regarding work. Sustained second-order change requires that the women's environments must also change. One-on-one interviews were conducted with the women in their homes using a semi-structured interview approach. The data were analyzed using predictor-outcome matrices. The simple answer to whether the women had found jobs was "no," as only two (17%) of the twelve women were employed for pay. The women not employed, however, represented three distinct sets: volunteers, students, and women not engaged in any work-related activities. The volunteers and students were engaged in activities that allowed them to maintain their benefits. The second research question addressed whether the employed women would be likely to maintain their work effort and achieve self-sufficiency. This research provided evidence that these women may be likely to sustain work, but will probably not attain self-sufficiency without either altering the definition of self-sufficiency, or fundamentally restructuring the supports available to them in the socio-cultural environment. Implications for future research, policy, and programming include additional longitudinal studies on child outcomes, and policy and programming that considers the environmental factors that may assist or hinder women's transition from welfare reliance to self-sufficiency.
70

A BIPHASIC ROLE FOR THE VOLTAGE-GATED SODIUM CHANNEL SCN5LAB IN CARDIAC DEVELOPMENT OF ZEBRAFISH

Bennett, Jeffrey Scott 17 June 2013 (has links)
A BIPHASIC ROLE FOR THE VOLTAGE-GATED SODIUM CHANNEL SCN5LAB IN CARDIAC DEVELOPMENT OF ZEBRAFISH JEFFREY S. BENNETT Dissertation under direction of Professor Dan M. Roden, M.D. Voltage-gated sodium channels (VGSCs) play an important role in generation and propagation of action potentials in nervous and cardiac tissues. Less is known of a possible role for them in development of the heart. Homozygous deletion of the voltage-gated sodium channel Scn5a results in embryonic lethality and developmental defects in the mouse heart. Morpholino knockdown of the two cardiac VGSC isoforms in zebrafish, scn5Laa and scn5Lab, results in small dysmorphic ventricles and death by four days post-fertilization. Here, I examine a role for scn5Lab in multiple phases of cardiac development. I find that loss of scn5Lab results in impaired specification of pre-cardiac mesoderm, with specific loss of the cardiac transcription nkx2.5. Differentiation of myocardium from the second heart field is determined to be intact, genetically and morphologically. Further I find that proliferation of differentiated cardiomyocytes is absent in morpholino-injected embryos, an effect that appears to be independent of impaired cardiac function. Electrophysiologic studies suggest voltage-gated sodium channels are present, but not required for action potentials at this time. I conclude that scn5Lab has a biphasic role in cardiac development of zebrafish, likely independent of its role in sodium ion permeation

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