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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.
11

THE CULTURAL POLITICS OF FETAL ALCOHOL SPECTRUM DISORDERS AND THE DIAGNOSIS OF DIFFERENCE

Hedwig, Travis H. 01 January 2013 (has links)
This dissertation is based on an ethnographic study of Fetal Alcohol Spectrum Disorders (FASD) and the racial, cultural and political considerations that shape the meaning of diagnosis for Alaska Native individuals and families in Anchorage, Alaska. During the period from August 6, 2010 to through August 5, 2011, I worked with foster families and extended natural families living with and supporting individuals diagnosed with FASD. Documenting the experiences of families in their interactions with clinical, state, tribal and non-profit institutions, I sought to understand how a diagnosis of FASD structures opportunities, outcomes and everyday life experiences across several critical life domains, including health, education, employment, kinship and identity. Family narratives and experiences are highlighted to illustrate the ways in which difference is reproduced in everyday public understanding and clinical practice.
12

Perceived behavioral control among non-pregnant women: a study of two behaviors related to fetal alcohol spectrum disorders

Hanson, Jessica Danielle 01 May 2012 (has links)
Maternal alcohol consumption during pregnancy is a public health concern due to the possible lifelong physical and cognitive effects in offspring. Prevention of alcohol-exposed pregnancies (AEP) should begin preconceptionally, either by preventing unintended pregnancies or by discouraging alcohol consumption in women who are at-risk for pregnancy. The purpose of this dissertation is to utilize the Theory of Planned Behavior's construct of perceived behavioral control (PBC)--including perceived power and control beliefs--to guide the measurement and understanding of two behaviors related to AEP among non-pregnant women: birth control use and binge drinking. For the first specific aim--to estimate the prevalence of alcohol-exposed pregnancies--a secondary data analysis was conducted using surveillance data from North Dakota and South Dakota women who have had a child with FAS. The FAS prevalence estimates (per 1,000 live births) in both states (ND=0.8/1,000; SD=0.9/1,000) were found to be higher than that calculated from national averages (0.7/1,000) using a comparable surveillance methodology. The goal of Specific Aim 2 was to determine risk for AEP among a random group of women, while Specific Aim 3 determined the control beliefs and perceived power to using birth control and decreasing binge drinking levels, and Specific Aim 4 focused on relating PBC of these two behaviors to behavioral intentions. Data for aims 2-4 were derived from a mailed, cross-sectional survey of 190 non-pregnant women randomly chosen from an electronic health records system in the upper Midwest. Of the 190 women included in the analyses, eight (6.6%) were binge drinking while being at-risk for pregnancy (i.e., being sexually active but not always using an effective form of birth control) (Specific Aim 2). This is lower than national estimates. For Specific Aim 3, there were high direct PBC scores for both birth control and binge drinking, and there was a positive correlation between birth control direct and indirect scores (although a negative correlation between binge drinking direct and indirect scores). Finally, Specific Aim 4 uncovered high intentions to both use birth control and to not binge drink. Also, the direct birth control PBC measure was significantly associated with birth control intention when controlling for other variables, although neither PBC nor intention appeared to be associated with actual birth control behavior. For binge drinking, the intention score and the direct measure of PBC were significantly associated with one another; as well, the direct measure of PBC and intention were both significantly associated with actual binge drinking behavior. Therefore, the relationship between PBC and intention was validated for both behaviors, and the association between PBC, intention, and actual behavior was indicated for binge drinking. Overall, the study both supported and disagreed with previous research, indicating that additional research with this theory and topic matter is necessary.
13

Social Cognition: Theory and Neuroscience in Fetal Alcohol Spectrum Disorders

Stevens, Sara 31 August 2012 (has links)
Children with fetal alcohol spectrum disorders (FASD) have deficits across many cognitive, behaviour and social domains. However, despite social difficulty being proposed as a main deficit following prenatal alcohol exposure, the nature of their deficient social behaviour is largely unknown. One process that may underlie difficulties in social functioning is poor social cognition, which refers to one’s understanding of the self, others and social world. The primary goal of this dissertation was to determine whether social cognitive deficits represent a core disability underlying the socio-behavioural problems of FASD using a bottom-up approach. The first level of this approach is represented by face processing. Global and independent face feature processing was compared between FASD and normal controls (NC) using experimental and clinical measures. Eye gaze processing was investigated next using experimental and clinical tasks. At the highest level of the bottom-up approach, social perspective taking, including theory of mind and empathy were examined, along with how these abilities related to parent-rated behaviour. Finally, the lowest level consisted of specific aspects of the social neural network. White matter in three limbic pathways was investigated using diffusion tensor imaging (DTI). Results generally supported the bottom-up approach of social cognition in FASD. These children showed impaired processing of face features, when matching mouth shapes and partially occluded identity, compared with NC. The FASD group was slower to process gaze and arrow cues, suggesting impaired attention shifting. Children with FASD also showed impairments in social perspective taking, including understanding false beliefs and empathy, and these impairments were related to parent-rated attention and social problems, and autistic-like traits. Deficits in theory of mind got worse with age in FASD and empathy showed distinct sex-related differences. Although no group differences were observed on DTI indices, groups did show different age-related changes in white matter. In conclusion, deficits at each level of the current bottom-up approach may underlie the social impairments in FASD and may contribute to their broader social behavioural phenotype. The results from this dissertation have potential to inform clinical practice and lead to more effective diagnostic and treatment approaches in FASD.
14

Long Term Effects of Early Embryonic Ethanol Exposure, on Behavioural Performance and Learning in Zebrafish, Danio rerio

Fernandes, Yohaan 31 December 2010 (has links)
Background: Fetal alcohol syndrome (FAS) is a devastating disorder whose mechanisms may be best investigated using animal models. Here we present a novel zebrafish FAS model to investigate the effects of low to moderate alcohol exposure during early development on learning. Methods: At 24-hours postfertilization zebrafish embryos were exposed to low doses of ethanol (external concentrations = 0.00, 0.25, 0.50, 0.75 and 1.00% vol/vol) for a very short duration (2 hours). Upon adulthood associative learning in the zebrafish was tested in a plus maze. Results: This exposure led to no gross anatomical abnormalities or increased morbidity or mortality. Overall activity was not significantly affected by embryonic ethanol exposure. A trend towards a dose-dependent decrease in learning and memory performance was observed. Conclusions: We suggest that zebrafish will be an appropriate model with which one can analyze the behavioural effects of embryonic alcohol exposure and the mechanisms of the ensuing abnormalities.
15

Long Term Effects of Early Embryonic Ethanol Exposure, on Behavioural Performance and Learning in Zebrafish, Danio rerio

Fernandes, Yohaan 31 December 2010 (has links)
Background: Fetal alcohol syndrome (FAS) is a devastating disorder whose mechanisms may be best investigated using animal models. Here we present a novel zebrafish FAS model to investigate the effects of low to moderate alcohol exposure during early development on learning. Methods: At 24-hours postfertilization zebrafish embryos were exposed to low doses of ethanol (external concentrations = 0.00, 0.25, 0.50, 0.75 and 1.00% vol/vol) for a very short duration (2 hours). Upon adulthood associative learning in the zebrafish was tested in a plus maze. Results: This exposure led to no gross anatomical abnormalities or increased morbidity or mortality. Overall activity was not significantly affected by embryonic ethanol exposure. A trend towards a dose-dependent decrease in learning and memory performance was observed. Conclusions: We suggest that zebrafish will be an appropriate model with which one can analyze the behavioural effects of embryonic alcohol exposure and the mechanisms of the ensuing abnormalities.
16

Social Cognition: Theory and Neuroscience in Fetal Alcohol Spectrum Disorders

Stevens, Sara 31 August 2012 (has links)
Children with fetal alcohol spectrum disorders (FASD) have deficits across many cognitive, behaviour and social domains. However, despite social difficulty being proposed as a main deficit following prenatal alcohol exposure, the nature of their deficient social behaviour is largely unknown. One process that may underlie difficulties in social functioning is poor social cognition, which refers to one’s understanding of the self, others and social world. The primary goal of this dissertation was to determine whether social cognitive deficits represent a core disability underlying the socio-behavioural problems of FASD using a bottom-up approach. The first level of this approach is represented by face processing. Global and independent face feature processing was compared between FASD and normal controls (NC) using experimental and clinical measures. Eye gaze processing was investigated next using experimental and clinical tasks. At the highest level of the bottom-up approach, social perspective taking, including theory of mind and empathy were examined, along with how these abilities related to parent-rated behaviour. Finally, the lowest level consisted of specific aspects of the social neural network. White matter in three limbic pathways was investigated using diffusion tensor imaging (DTI). Results generally supported the bottom-up approach of social cognition in FASD. These children showed impaired processing of face features, when matching mouth shapes and partially occluded identity, compared with NC. The FASD group was slower to process gaze and arrow cues, suggesting impaired attention shifting. Children with FASD also showed impairments in social perspective taking, including understanding false beliefs and empathy, and these impairments were related to parent-rated attention and social problems, and autistic-like traits. Deficits in theory of mind got worse with age in FASD and empathy showed distinct sex-related differences. Although no group differences were observed on DTI indices, groups did show different age-related changes in white matter. In conclusion, deficits at each level of the current bottom-up approach may underlie the social impairments in FASD and may contribute to their broader social behavioural phenotype. The results from this dissertation have potential to inform clinical practice and lead to more effective diagnostic and treatment approaches in FASD.
17

Microglial responses to ethanol exposure in a mouse model of fetal alcohol syndrome

Ahlers, Katelin Eloyce 01 December 2014 (has links)
Fetal alcohol exposure is the most common known cause of preventable mental retardation, yet we know little about how microglia respond to, or are affected by, alcohol in vivo. Using an acute (single day) model of moderate (3 g/kg) to severe (5 g/kg) alcohol exposure in postnatal day (P) 7 or P8 mice we have found that alcohol-induced cortical neuroapoptosis is closely correlated in space and time with the appearance of activated microglia near dead cells. Microglia found in close proximity to dying neurons selectively engulfed those that were in later stages of apoptosis. Remarkably, most dead cells were cleared and microglia began to deactivate within 1-2 days of the initial insult. Coincident with microglial activation and deactivation, in the 5 g/kg alcohol model, there was a transient but substantial increase in pro-inflammatory factor (PIFs) expression. Work in BAX-null mice demonstrated that microglial activation and PIF expression were linked to BAX-dependent neuroapoptosis. As such, the level of microglial activation scaled with alcohol-induced cell death. Therefore, acute alcohol exposure in the developing cortex causes transient microglial activation and mobilization, promoting clearance of dead cells and tissue recovery. Moreover, cortical microglia show a remarkable capacity to rapidly deactivate following even severe neurodegenerative insults in the developing brain. Given that alcohol exposure on either P7 or P8 induced comparable levels of neuroapoptosis and microglial activation, we hypothesized that alcohol exposure on two sequential days (P7 and P8) would exacerbate neuroapoptosis and extend microglial activation. Instead, we found that the period of neuroapoptosis and microglial activation was similar after one day of alcohol exposure on P7 or after two days of exposure on P7 and P8. This was true for both the moderate and severe alcohol paradigms. Potentially, the low levels of cell death produced by the second day of injection may be due to neuroprotective mechanisms elicited by the first day of alcohol injection. In support of this idea, a preliminary microarray analysis of cortical gene expression 12 and 24 h after 5 g/kg alcohol exposure shows a decrease in expression of several pro-apoptotic factors and an increase in the expression of pro-survival factors, including neurotrophins. Of particular interest, BDNF, which has previously been shown to inhibit alcohol-induced neuroapoptosis, showed an eight-fold increase in expression at 24 h following 5 g/kg alcohol exposure and in situ hybridization showed strong BDNF expression near cortical regions with high levels of cell death. Future studies will be needed to extend the analysis of microglial activation states in this two-day injection model and to further explore the possibility that BDNF expression by microglia enacts neuroprotective mechanisms against a second insult. Finally, work in cell culture has suggested that chronic alcohol exposure may potentiate or inhibit microglial phagocytosis of dead cells. These studies raise the possibility that alcohol may directly affect microglial mobility which is important for their surveillance and synaptic remodeling functions. Therefore, we measured the effect of increasing doses of alcohol (0, 0.25, 0.5 and 1%) on microglial migration, branch motility, and morphology in dissociated BV-2 cell cultures and in acutely isolated neonatal (P5-6) brain slices. The results indicate that alcohol dose-dependently inhibits microglial migration and ruffling in cell culture, but in brain slices even high alcohol concentrations (0.5%) only reduce microglial branch motility by ~2%. When combined with our evidence for efficient microglial phagocytic clearance of dead cells in the neonatal cortex, these data suggest that while there is a measurable effect of acute alcohol exposure on microglial mobility, it does not impede microglia from performing their surveillance and phagocytic functions in vivo.
18

Is Prematurity a Part of Fetal Alcohol Spectrum Disorder?

Bailey, Beth, Sokol, Robert J. 01 March 2008 (has links)
Since fetal alcohol syndrome was first reported, studies have demonstrated a range of perinatal/developmental abnormalities that fall under the umbrella term fetal alcohol spectrum disorders. Of these, low birth weight in exposed children is among the most commonly observed and widely accepted. However, in the past, assertion of an association between prenatal alcohol exposure and preterm birth was controversial. Methodological difficulties may have contributed to failure to consistently detect such a relationship. However, new evidence suggests that pregnancy drinking may be a major contributor to extreme, but not mild prematurity. Extreme prematurity is a major cause of severe perinatal morbidity and mortality. If recent findings are confirmed, it suggests that extreme prematurity might be reduced by eliminating prenatal alcohol exposure.
19

Whole Genome Bisulfuite Sequencing Methylation Analysis of Wnt7a In Embryonic Mouse Hearts Following Maternal Ethanol Binge

Shao, Richard 01 January 2023 (has links) (PDF)
Maternal binge alcohol consumption has been linked to congenital birth defects in the fetus. Said defects include abnormalities in heart development, a category of disease referred to as Congenital Heart Disease. Given the prevalence of Congenital Heart Disease, with a study showing around 49.9% of women having at least participated in binge alcohol consumption at least once during the early stages of their pregnancy and Congenital Heart Disease being linked to various complications in adulthood, this is a topic relevant to the clinical setting. Alcohol consumption has been linked to decreases in DNA methylation, which generally increases transcriptional expression of nearby genes. This thesis will focus on how alcohol affects the genomic-wide epigenetics of the embryonic heart with the aim of identifying specific genes and sites within those genes that are affected by alcohol exposure in utero. We hypothesize that embryonic mouse hearts exposed to ethanol will show a differential methylation pattern characteristic of hypomethylation versus control hearts not exposed to ethanol. To test this hypothesis, we used oral gavage to administer ethanol to pregnant mice at embryonic age E9.5 (a time associated with heart chamber formation). Maternal mice were sacrificed at E11.5, embryonic hearts were removed, and DNA was extracted for further experimentation with whole genome bisulfite sequencing. Analysis of whole genome bisulfite sequencing data showed a slight trend towards hypomethylation but suggested no significant changes in the overall methylation pattern in embryonic mouse hearts at the genomic level, but we have independently identified several genes whose expression is depressed in the embryonic mouse following a single maternal binge ethanol dose at E9.5, and thus we are investigating potential alcohol-induced DNA methylation alterations in specific target genes of interest. Future investigations into gene and site-specific DNA methylation profiles as well as other epigenetic modifications should prove useful in our quest to learn how maternal alcohol consumption causes cardiac malformations leading to congenital heart disease.
20

Overexpression of Serum Response Factor in Astrocytes Improves Neuronal Plasticity in a Model of Fetal Alcohol Spectrum Disorders

Paul, Arco P. 04 April 2012 (has links)
Neuronal plasticity deficits underlie many of the neurobehavioral problems seen in Fetal Alcohol Spectrum Disorders (FASD). Recently, we showed that third trimester alcohol exposure lead to a persistent disruption in ocular dominance (OD) plasticity. For instance, few days of monocular deprivation results in a robust reduction of cortical regions responsive to the deprived eye in normal animals, but not in ferrets exposed early to alcohol. This plasticity deficit can be reversed if alcohol-exposed animals are treated with a phosphodiesterase type 1 (PDE1) inhibitor during the period of monocular deprivation. PDE1 inhibition can increase cAMP and cGMP levels, activating transcription factors such as the cAMP response element binding protein (CREB) and the Serum response factor (SRF). SRF is important for many plasticity processes such as LTP, LTD, spine motility and axonal pathfinding. Here we attempt to rescue OD plasticity in alcohol-treated ferrets using a Sindbis viral vector to express a constitutively active form of SRF during the period of monocular deprivation. Using optical imaging of intrinsic signals and single unit recordings we observed that overexpression of a constitutively active form of SRF (Sindbis SRF+), but neither its dominant negative (SRF-) nor GFP, restored OD plasticity in alcohol-treated animals. Surprisingly, this restoration was observed throughout the extent of the primary visual cortex and most cells infected by the virus were positive for GFAP rather than NeuN. Hence, we further tested whether overexpression of SRF exclusively in astrocytes is sufficient to restore OD plasticity in alcohol-exposed ferrets. To accomplish that, first we exposed cultured astrocytes to the SRF+, SRF- or control GFP viruses. After 24h, these astrocytes were implanted in the visual cortex of alcohol-exposed animals or saline controls one day before MD. Optical imaging of intrinsic signals showed that alcohol-exposed animals that were implanted with astrocytes expressing SRF, but not SRF- or GFP, showed robust restoration of OD plasticity in all visual cortex. These findings suggest that overexpression of SRF exclusively in astrocytes can improve neuronal plasticity in FASD.

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