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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.
661

Help-Seeking for Depression in Rural Women: A Community Portrait

Fisher, Vicky Mitchell 01 January 2005 (has links)
This study was conducted with fourteen participants who lived in a rural Virginia community. The focus of the study was exploration of the nature of the experience of depression and of help-seeking for depression in one rural woman and in her community social network. The need for exploration of the community social network was influenced by the DeFacto Services Model of Rural Mental Health, which emphasized the influence of community factors in making decisions to seek mental health care. Findings of the study included the following themes, which related to the nature of depression: 1) linkage of experiential depression to diagnostic criteria; 2) overcoming depression using willpower; 3) connection of depression to abuse and violence, and 4) masking the inner world of depression. The following themes related to the nature of help-seeking emerged from the data: 1) family role in help-seeking; 2) insider/outsider status impact on help-seeking; 3) role of family and work functioning in help-seeking, and 4) role of informal and formal networks in help-seeking. Tentative conclusions were reached based on the findings that suggest depression and help-seeking may be experienced in distinctive ways by rural dwelling women in this particular community. Further research was suggested as a way of understanding more about how rural women seek help for depression within the context of their own community social networks.
662

CREATION OF A MOUSE WITH A HUMANIZED fpgs GENE COMPATIBLE WITH NORMAL DEVELOPMENT

Xie, Linying 01 December 2008 (has links)
Abstract: Folylpoly-γ-glutamate synthetase (FPGS) catalyzes the formation of polyglutamate forms of the reduced folates and antifolates such as methotrexate (MTX) and pemetrexed; this allows the retention of folates and antifolate cancer drugs inside the cell. The enzyme activity of FPGS is essential for cell proliferation and survival. The mouse fpgs gene contains two promoters spaced 10 kb apart which are activated in a tissue-specific manner. The upstream promoter (P1) and exons A1a and A1b are used in some differentiated tissues, mainly liver and kidney, whereas the downstream promoter (P2) and exon 1 are used in rapidly dividing cells. In contrast, the human fpgs gene expresses virtually all transcripts from the downstream promoter. In order to more faithfully mimic human folate metabolism in the mouse, we have deleted the upstream promoter and the associated two small exons of fpgs in the mouse genome by homologous recombination. Homozygous deletion mice survive embryonic development, grow to adulthood, and reproduce through several generations, they appear to be normal. The results of Q-RT-PCR analysis on RNA from adult mouse liver of three different genotypes (A1aA1b +/+, +/-, -/-) indicated that deletion of P1 results in the release of promoter interference of P2, and activation of the downstream P2 promoter is increased by 3-5 fold. Interestingly, the total FPGS mRNA expression in KO mouse liver is 20-100 fold lower than in liver from wild-type mice. However when the FPGS activity was measured using an FPGS enzyme assay, the liver of knockout mice appeared to have only 2 fold lower enzyme activity than liver from wild-type mice. In conclusion, we have successfully generated a mouse which reflects human folate metabolism much closer than seen in wild type mice. The FPGS- humanized mouse liver model would be an appropriate in vivo tool for the study of the antifolate drug toxicity and inhibition.
663

FUNCTIONAL HEALTH LITERACY AND THE USE OF DENTAL SERVICES IN YOUNG CHILDREN

Fries, Melissa 28 April 2009 (has links)
Purpose: The purpose of this study is to examine parental Functional Health Literacy and their child’s subsequent utilization of dental services. Methods: This was a prospective cohort study of children (n=1175) enrolled in the Child Health Investment Partnership of Virginia (CHIP). Descriptive statistics and separate multivariate logistic regressions were used to determine the relationship between functional health literacy measures; 1) Health Care Literacy (HCL), 2) Personal Health Literacy (PHL), and 3) LSP 22 scale, with utilization as measured as number of dental visit/s. Results: Descriptive analysis of the cohort reveals: 45% black, 40% white, 10% Hispanic, 5% other, 41% of parents not having a high school diploma or GED, >75% were enrolled in CHIP by the age of one, 90% had Medicaid, 80% lived in Roanoke City, 87% had a normal birth weight, 86% were term pregnancies, and 91% did not have asthma. All literacy measures, PHL, HCL, LSP 22, and LSP 22 Target Range were positively associated with having dental utilization. Hispanic race had a less likely chance of having multiple dental visits even when within target range of LSP 22. Conclusion: Parents of children enrolled in CHIP with higher levels of functional health literacy as measured by the Life Skills Progression Instrument demonstrated an increased likelihood of dental utilization for their children.
664

Association Between Preconception Multivitamin Use and the Risk of Preeclampsia/High Blood Pressure in Pregnant Women

Allen, Krisandra 04 December 2009 (has links)
Gestational Hypertension and Preeclampsia are significant causes of morbidity and mortality among pregnant women and neonates. This study examined the relationship between multivitamin use and incidence of reported high blood pressure or preeclampsia using data from the 2007 Oregon State Pregnancy Risk Assessment Monitoring System (PRAMS). Overall there were n=1894 women included in the study. Women were asked two to four months after delivery to report their multivitamin or prenatal vitamin usage in the month prior to conception and were categorized as daily users, or less than daily users. The unadjusted prevalence of high blood pressure or preeclampsia was 13.4% among daily users and 11.9% among nonusers. The study showed that the association between multivitamin use and preeclampsia was modified by BMI. Upon adjustment for parity, diabetes, pregnancy intent, abuse, and maternal age, analysis stratified by maternal pre-pregnancy BMI revealed a borderline significant protective effect among daily multivitamin users with a BMI less than 30 (OR 0.48, 95% CI [0.22,1.04]), and a significant risk for women with a BMI greater than 30 (OR 2.74, 95% CI [1.02,7.40]). This study showed the potential impact of multivitamin on preeclampsia among obese and non-obese women. Additional investigations are needed to examine the association and potential biologic mechanisms for this association need to be explored.
665

Physiological and Molecular Characterization of Genetic Competence in Streptococcus sanguinis

Rodriguez, Alejandro 21 July 2008 (has links)
The ability of bacteria to assimilate free DNA from the environment is known as competence. Though many studies have focused on competence regulation in Streptococcus pneumoniae and Streptococcus gordonii, Streptococcus sanguinis has yet to be examined. Physiological characterization of competence in S. sanguinis strain SK36 and its comC mutant, JFP41, led to the genome-wide transcriptional analysis of cells induced to competence via addition of competence-stimulating peptide (CSP). A total of 128 genes were induced at least 2-fold, 74 of which were classified as either “early” or “late” based on their induction patterns. Expression patterns were verified using qRT-PCR. This study identified genes not up-regulated in S. pneumoniae or S. gordonii and lays the foundation for bioinformatic studies to identify conserved binding sites upstream from CSP-regulated genes. These results also shed light on the possible existence and identity of expected CSP exporters in S. sanguinis, which have so far eluded discovery.
666

COMPARATIVE ANALYSIS OF TORSIONAL STRENGTH BETWEEN PROFILE® GT® AND GT® SERIES X(TM) NICKEL TITANIUM ROTARY INSTRUMENTS

Reynolds, Jake 21 April 2009 (has links)
The purpose of this study was to compare the resistance to fracture by the twisting of two nickel titanium (NiTi) rotary file systems. The Profile® GT® (GT) and the GT® Series X(TM) (GTX) files were tested to analyze the maximum torsional strength and the maximum angular deflection at the time of separation of the files. For each system, ten new files were tested at each of the following eight taper/size designations for a total of 160 files: 20/0.04, 20/0.06, 30/0.04, 30/0.06, 30/0.08, 40/0.04, 40/0.06, and 40/0.08. The American National Standards Institute / American Dental Association Specification No. 28 was implemented to evaluate torsional limits for these intruments. Files were mounted in a Maillefer Torsiometre machine, which records maximum torsional strength and angular deflection at separation for each file. A two-way ANOVA revealed significant differences after comparing the size and type of file. The GT files required significantly more torque to separate than the GTX files in all groups tested except the GTX file size 20/0.06, which required significantly more maximum torque than the GT file, with no significant difference between the GT and GTX files for size 30/0.04. The GT files exhibited values for angular deflection at separation that were significantly higher than those for the GTX files at sizes 30/0.04 and 40/0.08 and the GTX files exhibited higher values at size 30/0.08 with no significant difference between the brands at the remaining five file sizes. In summary, the GT files required significantly more torque to fracture and exhibited values for angular deflection at separation that were significantly higher than the GTX files for in 6 of 8 and 2 of 8 file sizes, respectively.
667

Specific Levels of Therapeutic Ultrasound Stimulate the Release of Inflammatory and Angiogenic Mediators From Macrophages In Culture

Turner, Thomas 27 July 2009 (has links)
Therapeutic ultrasound (TUS) is a treatment modality that is used to accelerate tissue healing. TUS is thought to affect cellular processes of tissue healing, especially those that occur in the inflammatory and early proliferative phases. TUS can be applied using various parameter selections including intensity, wavelength, duty cycle and treatment duration and no clear consensus exists on optimal parameters for healing enhancement. Macrophages are important mediators of inflammation and their actions are critical to normal progression into the proliferative phase of healing. They complete many functions during these periods of tissue healing, among those being release of cytokines and growth factors. These paracrine factors affect other inflammatory cells, resident cells of the healing tissue, including fibroblasts and endothelial cells that are necessary for restoration of damaged tissue. The hypothesis of this investigation is that TUS enhances early healing, in part, through stimulation of macrophage release of paracrine factors involved in coordination of the cellular aspects of tissue healing and that specific levels of TUS are most stimulatory for macrophages. This study examined macrophage release of interleukin-1beta (IL-1Beta), vascular endothelial growth factor (VEGF), transforming growth factor-Beta 1 (TGF-B1) and fibroblast mitogens, in response to varied levels of TUS. Fibroblasts incubated up to 48-hours in media conditioned by TUS-stimulated macrophages were not induced to proliferate regardless of the parameters sets of TUS applied. TUS (1 MHz, 400mW/cm2 SATA, 20% duty cycle, 10-minute exposure) induced macrophage release of VEGF and IL-1Beta within 10-minutes post-TUS, without any additional release being stimulated at 1-hour post-insonation. No other combination of TUS parameters studied induced release of IL-1Beta and VEGF. TUS did not induce release of TGF-Beta 1 at either time point post-TUS. VEGF and IL-1Beta release occurred in conjunction with lactate dehydrogenase (LDH) release from treated macrophages, indicating non-specific cell membrane permeabilization was involved in the cellular response. For IL-1Beta, TUS-stimulated release was inhibited at lower exposure temperatures. Inhibition of TUS-induced release at lower temperatures indicates that a cellular metabolic process, most likely exocytosis, was also stimulated by TUS. Based on these results, it appears that TUS exposure at 1 MHz, 400mW/cm2 SATA, 20% duty cycle induces non-specific and cell-mediated release of secretory proteins. Thus, enhanced release of cytokines and growth factors from macrophages is a possible mechanism by which TUS enhances tissue healing.
668

Dendritic Spine Density Varies Between Unisensory and Multisensory Cortical Regions

Bajwa, Moazzum 07 May 2010 (has links)
In the brain, the dendritic spine is a point of information exchange that extends the neuronal surface on which synapses occur, as well as facilitates and stabilizes those contacts. Furthermore, dendritic spines dynamically change in shape and number in response to a variety of factors. Dendritic spine numbers are reduced in mental retardation, enhanced during development, sensory enrichment or physical exercise, or fluctuate during the reproductive cycle. Thus, for a given neuron type, it might be expected that dendritic spine number might achieve a dynamic optimum. Indeed, many studies of spine density of pyramidal neurons in sensory cortex indicate that an average of ~1.4 spines/micron occurs is present (Briner et al., 2010). Most such studies examined dendritic spines from primary sensory areas which are dominated by inputs from a single sensory modality. However, there are a large number of neural regions that receive inputs from more than one sensory modality and it is hypothesized that spine density should increase to accommodate these additional inputs. To test this hypothesis, the present experiments used Golgi-Cox stained layer 2-3 pyramidal neurons from ferret primary somatosensory (S1) and auditory (A1) cortical regions, as well as from the higher-level rostral posterior parietal (PPr) and lateral rostral suprasylvian (LRSS) multisensory areas. Spine densities in S1 (avg 1.309 ± 0.247 spines/micron) and A1 (avg 1.343 ± 0.273 spines/micron) were measured to be significantly greater (p<0.05, t-test) than those observed in multisensory regions PPr (avg 1.242 ± 0.205 spines/micron) or LRSS (avg 1.099 ± 0.217 spines/micron). These results also indicate that spine densities are greater in primary (S1, A1) than in higher-level (PPr, LRSS) sensory areas. The functional consequences of such unexpected findings are discussed in light of potential biophysical differences between unisensory and multisensory neurons.
669

Purification and Characterization of a Methyl-DNA Binding Protein Complex from Primary Erythroid Cells

Kransdorf, Evan Paul 01 January 2004 (has links)
The chicken embryonic β-type globin gene, ρ, is silenced on day five of embryogenesis. Concomitant with this silencing is methylation of cytosine residues in the promoter and proximal transcribed region of the gene, which is first detected on day seven and is complete in adult cells. Once methylated, expression of the gene cannot be induced unless the methylation is removed by treatment of cells with Sazacytidine. Therefore ρ-globin is a member of a small group of genes whose normal developmentally regulated expression is mediated at least in part by DNA methylation.A methyl-DNA binding complex, termed the MeCPC (Erythroid Methyl Cytosine-binding Protein Complex), has been found to bind to the methylated, but not unmethylated, ρ-globin promoter and proximal transcribed region in nuclear extracts from definitive erythrocytes. This complex has a stronger binding affinity for its cognate binding sequence, the methylated ρ-globin proximal transcribed region (M-ρ248), than for an artificial 5-methylcytosine-rich sequence (M-CG11).To define the components of the MeCPC, we developed two chromatographic procedures to purify the complex from adult chicken red blood cell nuclear extracts (Purification Strategies I and II). Mass spectrometry was performed on the MeCPC obtained by Purification Strategy I and proteins were identified by a novel application of peptide mass fingerprint data fitting. Four components of the previously-purified MeCPl transcriptional repression complex were identified in the sample: MBD2, RbAp48, HDAC2 and MTA1. Another identified protein, MENT, is a factor expressed only in chicken hematopoietic cells. These five proteins, as well as the MeCPl component Mi2, were found to tightly coelute by Western blotting of gel-filtration fractions from Purification Strategy II. Therefore, we conclude that these five proteins are components of the MeCPC.To confirm that MBD2 is associated with the ρ-globin gene in vivo, we perfomed the chromatin immunoprecipitation assay using anti-MBD2 antibodies. In adult erythrocytes, significant enrichment for MBD2 is seen at the transcriptionally inactive ρ-globin gene, but no enrichment is observed at the transcriptionally active βA globin gene. These experiments confirm that MBD2 binds to the methylated p-globin gene in adult chicken erythroid cells.
670

Immunological and Molecular Analyses of the Borrelia burgdorferi OspF Protein Family F

Tran, Emily 01 January 2006 (has links)
In North America, Borrelia burgdorferi is the primary causative agent of Lymedisease which is a growing health concern. The ability of B. burgdorferi to maintain chronic infection indicates that they are capable of immune evasion. A distinguishing characteristic of B. burgdorferi is the large number of sequences encoding predicted or known lipoproteins, including outer surface protein F (OspF). This study analyzes the specificity of the humoral immune response to B. burgdorferi B3 IMI OspF proteins during murine and human infection. Immunoblot analyses revealed a temporal expression of OspF proteins during infection and mapped the immunodominant epitopes which lie within the variable domains. To determine if OspF-related proteins are produced by other isolates, immunoblot analyses were performed using sera collected from mice and humans infected with diverse B. burgdorferi strains. Differences in the immunoreactivity profile to OspF proteins were seen among the infection sera tested. To identify the molecular basis of these differences, the ospF gene was isolated from several strains, sequenced and evolutionary analyses were conducted. These analyses revealed that OspF proteins show little diversity despite the separate geographic locations from which isolates originated. The high degree of OspF protein conservation seen in isolates from two distinct regions emphasizes the potential for OpsF proteins as vaccinogens or in serodiagnostic assays. Altogether, this study demonstrates the potential contribution of OspF proteins to immune evasion through its temporal expression during infection which may play specific roles at different stages of infection. Studies are underway to determine if inactivation of ospF genes through allelic exchange mutagenesis impacts on the pathogenicity of the Lyme disease spirochetes.

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