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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.
251

Towards the identification of environmental exposures and epigenetic marks related to the etiology of Autism

Miemczyk, Stefan January 2017 (has links)
Autism is a complex disorder with possible genetic, epigenetic and environmental components. As the etiology remains uncertain and an increase in incidence is suspected, the involvement of possible environmental risk factors has gained increasing attention. With this thesis, I aim to provide tools for assessing such risk factors. Firstly, I aim to construct a questionnaire for the analysis of an environmental component in the etiology of autism. Secondly, I aim to assess the importance of prenatal exposure to metals in certain diseases and thirdly I aim to construct a methodology enabling the analysis of the mitochondrial epigenome, which is especially interesting in relation to autism as mitochondrial diseases occur more frequently in an autistic population than in the general population. For the creation of the questionnaire the scientific literature was reviewed. The resulting questionnaire contains general, prenatal, neonatal and paternal risk factors. The metal analysis was conducted on the cord blood of patients who later developed autism, antinuclear antibodies positive rheumatoid arthritis or diabetes, which were then compared to healthy control subjects. My findings propose a link between elevated levels of cord blood cadmium or aluminum and rheumatic arthritis. In addition, elevated aluminum levels might be associated with autism. In regards to the analysis of the mitochondrial epigenome, to my knowledge, no standard protocol exists with frozen human whole blood as a source. In this thesis, I succeeded in creating the basis for such a protocol, however still needing several small modifications for an increased overall yield.
252

The effects of Autistic Spectrum Disorders (ASD) on attachment : experiences of mothers from diverse South African socio-economic groups.

Wortmann, Lorin 02 April 2013 (has links)
Attachment theory is concerned with the relational ‘tie’ that exists between a mother and her child, which is said to play an imperative role in a child’s mental development and future attachment relationships. Although there is extensive research on attachment theory on an international scale, there is a paucity of information with regard to this in the South African context. The object of this study is to investigate mothers’ experiences of attachment with their child who has an Autistic Spectrum Disorder (ASD). In addition this research aims to investigate whether this attachment relationship between a mother and her ASD child differs, or is the same across diverse socio-economic groups in the South African context. This research was qualitative in nature, which elicited rich, descriptive and personal accounts of mothers’ experiences of attachment with their ASD child across diverse socio-economic groups. Twelve participants from advantaged and disadvantaged communities from Johannesburg and the greater Johannesburg area were invited to participate in this study. Data was gathered through semi-structured interviews and analysed using thematic content analysis. Seven themes emerged from this study which explored mothers’ experiences of attachment with their ASD child. In addition, similarities and differences were found in mothers experiences of attachment across the diverse socio-economic groups.
253

Effects of the relationship enhancement® program on social skills, empathy and social support for adults with autism spectrum disorders

Unknown Date (has links)
An important area of research is emerging for adults diagnosed with autism spectrum disorders (ASD) with respect to the challenges they face in their social relationships. Social relationships include those that are romantic in nature such as dating, cohabitation and marriage. Researchers suggest that engaging in a healthy and happy romantic relationship has many physical and mental health benefits that contribute to improved quality of life. This study used a quasi-experimental group design to explore the effects of psychoeducation for adults with ASD. Study participants were assigned to one of two group conditions. One group received the Relationship Enhancement®(RE) program and the other received RE with supplements targeting specific social skills. Social skills, empathy and social support were measured pre and post intervention for participants both within and between groups. Significant differences were found in the assessment of all participants, in both groups, as measured by t-tests and effect sizes in the variables of social skills (t(37)=- 2.28-2.72, p=.028-.029, η2=.122) and empathy (t(37)=-2.31, p=.027, η2=.123). These differences indicate that all participants, in both groups improved in social skills and empathy from pre to post treatment. No significant differences were found among all group participants for the variable of social support. There were no significant differences between groups for the three variables measured (p>0.05). Overall, these results provide support for the use of RE and the targeted supplements to increase social skills and empathy among adults with ASD who are interested in engaging in romantic relationships. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
254

Estudo de genes candidatos aos Transtornos do Espectro Autista / Study of candidate genes to Autism Spectrum Disorders

Ribeiro, Cintia Marques 07 June 2013 (has links)
Os transtornos do espectro autista (TEA) são condições neuropsiquiátricas caracterizadas por padrões comportamentais estereotipados, ausência ou limitação de comunicação verbal e de interação social recíproca. Diversos estudos têm mostrado que esses transtornos possuem etiologia genética complexa e heterogênea, o que dificulta a identificação dos fatores causais. Estima-se que cerca de 70% dos casos de TEA são idiopáticos. Portanto, com o objetivo de identificar mecanismos etiológicos associados aos TEA, utilizamos as seguintes estratégias: customização de uma lâmina de microarray CGH que possibilite a detecção não só de grandes CNVs, mas também de alterações menores do que 10 kbp, em exons e regiões UTR de genes potencialmente candidatos; a comparação entre os tipos de rearranjos detectados em pacientes sindrômicos e em não sindrômicos e, ainda, a investigação mais detalhada de uma família com indivíduos portadores de transtorno autista e síndrome de Asperger. Foram avaliados 103 portadores de TEA não sindrômicos e 18 sindrômicos, sendo as taxas de detecção de alterações potencialmente patogênicas, respectivamente, de 11,6% e 38,9%. Dentre as alterações detectadas 44,4% são menores do que 10 Kbp. Portanto, a estratégia de usar uma lâmina customizada, com alta densidade de sondas complementares aos exons e regiões não codificantes de genes potencialmente envolvidos na etiologia dos TEA, capaz de detectar tanto alterações grandes quanto pequenas, parece ser relevante na tentativa de elucidar o maior número de casos possíveis e melhor compreender esses transtornos. Além disso, essa lâmina também pode ser utilizada como uma ferramenta para auxiliar o diagnóstico clínico e o aconselhamento genético com um custo mais acessível em comparação a outras comerciais ou ao sequenciamento de última geração. Cerca de 33,3% das CNVs observadas afetam região UTR, sugerindo que mutações nessas regiões podem explicar uma proporção significativa dos casos nos quais não são detectadas alterações através de outros testes genômicos, visto que a maioria desses ainda não exploram adequadamente regiões não codificantes. Entre os pacientes autistas não sindrômicos verificou-se que a maioria dos genes afetados por CNVs estão envolvidos em duas principais funções biológicas - sinapses glutamatérgicas e orientação axonal, sugerindo que TEA não sindrômico pode ser causado por disfunção em genes diferentes envolvidos em processos fisiológicos comuns. Diferente do que observamos entre pacientes não sindrômicos, detectamos mais de uma alteração em um mesmo indivíduo ou alterações que englobam mais de um gene entre os pacientes sindrômicos, reforçando o modelo oligogênico para alguns casos de TEA. Por fim, os dados obtidos no estudo da família com portadores de síndrome de Asperger e transtorno autista sugere que a gravidade do quadro clínico possa estar relacionada ao número de mutações e possivelmente por duas mutações diferentes em ambos os alelos de um mesmo gene. Nossos resultados, além de apoiar o envolvimento dos genes MDGA2, FHIT, HTR2A, SHANK2, GRIA3, ZNF778, PRKCα, CDH15, DIAPH3, GCH1, GRM5, MARK1, SLC17A6, IMMP2L, BZRAP1, SYNGAP1, ANK3, MAP1A, GABRR2 e LAMC3 nos TEA também sugere novos genes candidatos: LRRC7, LRRIQ3, CADPS1, NUFIP, SEMA3A, SNAP29, MBD2, GAD2, DGKH e PARD3 / The autism spectrum disorders (ASD) are neuropsychiatric conditions typically characterized by social deficits, communication difficulties, stereotyped or repetitive behaviors and interests. Several studies have shown that these disorders have a complex and heterogeneous genetic etiology, which makes difficult to identify the causal factors. Approximately 70% of cases are idiopathic. In order to identify etiological mechanisms associated with ASD, we have used the following strategies: customized a microarray CGH platform that allows detection not only of large CNVs, but also alterations smaller than 10 kbp in exons and UTR regions of potential candidate genes, the comparison between the types of rearrangements detected in syndromic and non-syndromic patients and further, more detailed investigation of a family segregating both autistic disorder and Asperger syndrome. We evaluated 103 nonsyndromic and 18 syndromic patients by the custom-designed array and the detection rate of possibly pathogenic alterations were, respectively, 11.6% and 38.9%. Among these CNVs, 44.4% are smaller than 10 kbp. Therefore, the strategy of using a custom-designed array, enriched with probes targeted to genes potentially involved in the ASD etiology and able to detect both large and small CNVs, seems to be relevant in an attempt to elucidate the largest number of cases and to better understand these disorders. Furthermore, this platform can also be used as a tool to support the clinical diagnosis and genetic counseling with a more affordable cost compared to conventional other or next-generation sequencing. Approximately 33.3% of the observed CNVs affect UTR region, suggesting that mutations in non-coding regions might explain a significant proportion of ASD cases negative for most genomic screenings, which still do not explore adequately these regions. Among nonsyndromic autistic patients we found that most of the genes affected by CNVs are involved in two main biological functions - glutamatergic synapses and axonal guidance, suggesting that nonsyndromic ASD can be caused by dysfunction in different genes of a few common physiological processes. In contrast to our findings in nonsyndromic patients, we detected more than one alteration in a single individual or alterations that involve more than one gene among the syndromic patients, reinforcing the oligogenic model for some cases of ASD. Finally, the data obtained in the study of the family segregating both Asperger syndrome and autistic disorder suggests that the severity of ASD seems to be modulated by the number of hits and possibly by hits in both alleles of the same gene. Our results support the involvement of genes MDGA2, FHIT, HTR2A, SHANK2, GRIA3, ZNF778, PRKCα, CDH15, DIAPH3, GCH1, GRM5, MARK1, SLC17A6, IMMP2L, BZRAP1, SYNGAP1, ANK3, MAP1A, GABRR2 and LAMC3 in ASD etiology and also suggests new candidates: LRRC7, LRRIQ3, CADPS1, NUFIP, SEMA3A, SNAP29, MBD2, GAD2, DGKH and PARD3
255

Evaluation of Mismatch Negativity as a Biomarker for Autism Spectrum Disorder

Green, Heather Lee January 2016 (has links)
Finding an early and objective way to identify language impairment in autism spectrum disorder (ASD) has the potential to lead to earlier speech and language intervention for affected children. Previous magnetoencephalography studies utilizing the mismatch field component (MMF) component have shown that increased MMF latency is a predictor of language impairment in children with ASD. We attempted to replicate these results using the mismatch negativity (MMN), the electroencephalography (EEG) equivalent of MMF. EEG was recorded in children ages 5 to 10 with ASD plus language impairment (ASD +LI), ASD minus language impairment (ASD –LI), and typically developing controls (TD) during a passive auditory oddball experiment presenting speech and nonspeech sounds. Contrary to previous MMF findings, individuals with ASD +LI demonstrated decreased MMN latency in the left hemisphere in response to novel vowel sounds compared to individuals with ASD –LI and TD controls. A positive correlation between left hemisphere MMN latency and language scores on the Clinical Evaluation of Language Fundamentals was found when combining both ASD groups. Our results lend support to the theory that some children with ASD +LI have increased connectivity in primary sensory cortices at the expense of computational connectivity between association areas of the brain. This may account for faster speech sound processing despite low language scores in these children. Further research needs to be done in order to determine if grouping children by hyper– versus hyposensitivity to auditory stimuli could explain conflicting results between studies and elucidate a neurophysiological biomarker of language impairment in subgroups of children with ASD.
256

Altered immune function associated with neurophysiologic abnormalities and executive function deficits in children with autism spectrum disorders. / CUHK electronic theses & dissertations collection

January 2010 (has links)
In study one, the executive functioning of 19 high-functioning (HFA) and 19 low-functioning (LFA) children with ASD were compared to 28 children with normal development using a battery of neuropsychological tests. Results not only confirmed previous knowledge that children with ASD had significant executive dysfunctions compared with children with normal development, but also extended it to show that LFA children were significantly more impaired than HFA children. Study two built on this knowledge and examined whether immunological abnormalities are associated with the differential executive dysfunctions in 18 HFA and 19 LFA children. Results indicated that LFA children showed greater executive dysfunctions as well as higher levels of total lymphocyte, T lymphocyte and suppressor/cytotoxic T lymphocyte levels than HFA children. In addition, executive dysfunctions were significantly associated with the three lymphocyte levels, lending support to the notion that immunological factors may play a role in the cognitive dysfunctions in individuals with ASD. Study three further examined whether the differential executive dysfunctions and immunologic levels in LFA and HFA children are associated with their neural connectivity. Results on 17 HFA and 14 LFA children showed that LFA children had significantly elevated theta coherence in the anterior network, as well as at the left intra-hemispheric and right-to-left inter-hemisphere connections than HFA children. LFA children also had significantly elevated immunologic level specifically in suppressor/cytotoxic T lymphocytes. Furthermore, the executive dysfunctions, disordered neural connectivity, and abnormal immunologic levels were found to be associated. / Recent evidence suggests that deficient executive functions are fundamental to the cognitive deficits in Autism spectrum disorders (ASD). It has been suggested that individuals with ASD have disrupted neural connectivity including that in the frontal lobes that mediate executive functions. With reports of immunologic abnormalities in children with ASD, it is plausible that such abnormalities disrupt the neural connectivity in the brains of individuals with ASD. There is, however, relatively little empirical evidence to support the notion. This dissertation reports on three studies to examine whether the executive dysfunction in children with ASD is associated with their immunologic abnormalities and disordered neural connectivity. / These findings have provided some initial evidence to support the notion that immunologic factors may play a role in causing neuronal damage in the anterior region of the brains of children with ASD, which is manifested in their disordered neural connectivity of that region, and their executive dysfunctions mediated by that same region. / Han, Yvonne Ming Yee. / Adviser: Agnes Chan. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 103-132). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
257

Inkluze žáků s poruchou autistického spektra v základní škole / Inclusion of pupils with autistic spectrum disorder at elementary school

Vít, Zbyšek January 2019 (has links)
The thesis Inclusion of Pupils with Autistic Spectrum Disorder at Primary School focuses on the inclusion of pupils with autism spectrum disorders and on how to work with them at primary school. The first chapter of the theoretical part describes the inclusion and its legislative framework. This chapter shows an overview of the support and counselling system in school education. The following chapters are devoted to the description of autism, its types and diagnostics of pupils with autistic spectrum disorders. The final theoretical part pays attention to devoted to educational methods and strategies for pupils with autistic spectrum disorders. It describes how to communicate with such pupils and what didactic systems can be used when working with them. The empirical part of the thesis describes the development of application for pupils with autistic spectrum disorder and its verification for the android mobile platform. The author of this thesis has developed the application mentioned above. This chapter describes both the design and the technical development of the application. The application is validated by using the research method of a controlled interview with parents and pupils where the application was tested for two months and these interviews are subsequently evaluated. The end of the...
258

Etude fonctionnelle et structurale de variants rares des contactines et vulnérabilité à l’autisme / Structural and functional analysis of contactin rare variants and susceptibility to autism

Mercati, Oriane 25 October 2013 (has links)
Les troubles du spectre autistique (TSA) affectent un individu sur 100 et sont caractérisés par des déficits de la communication et des interactions sociales, et par des comportements restreints et répétitifs. Les TSA présentent une forte composante génétique ; les premiers gènes impliqués ont été identifiés au laboratoire et codent des protéines d’adhérence ou d’échafaudage localisées à la synapse : les neuroligines (NLGN) et SHANK. Nous nous sommes intéressés à l’implication dans les TSA des contactines (CNTN), un groupe de six molécules d’adhérence neurales de la superfamille des immunoglobulines. Ces protéines sont ancrées à la membrane plasmique par un groupement glycosyl phosphatidylinositol (GPI) et peuvent être sécrétées par clivage du GPI. Elles interviennent dans des processus variés du développement neuronal comme la croissance neuritique, le guidage et la fasciculation des axones ou la myélinisation. Des études génétiques ont suggéré l’implication des contactines 4 à 6 dans les TSA, mais aucune étude fonctionnelle n’a confirmé cette hypothèse. Ce travail de thèse associe une analyse génétique, une analyse fonctionnelle sur des cultures de neurones primaires de rat et une analyse structurale par modélisation moléculaire. Nous avons identifié plusieurs "Copy-Number Variants" (CNV) dans les gènes CNTN (essentiellement des délétions affectant CNTN5 et CNTN6) et observé une tendance à l’enrichissement chez les patients par rapport aux individus témoins. Le séquençage des exons codants de CNTN5 et CNTN6 chez plus de 200 patients et 200 témoins nous a ensuite permis d’identifier des variants ponctuels non synonymes. Les variants privés (présents chez un seul individu ou dans une seule famille) sont plus fréquents chez les patients que chez les témoins. Les CNV et les variants ponctuels sont hérités, de parents pour la plupart non atteints, ce qui suggère que les altérations des contactines constituent des facteurs de vulnérabilité aux TSA plutôt que des facteurs causaux. Afin de déterminer l’effet fonctionnel des variants ponctuels rares, nous avons comparé l’effet sur la neuritogenèse des CNTN mutées à celui des CNTN sauvages. Nous avons ainsi analysé, sur plusieurs centaines de neurones par condition, la longueur et la ramification des neurites dans un système de co-culture avec des cellules HEK surexprimant la CNTN. La plupart des protéines CNTN5 et CNTN6 mutées présentent des effets différents de ceux des protéines sauvages (inhibition ou augmentation des effets positifs de celles-ci). Le dernier objectif de cette étude consistait à évaluer l’influence de certains de ces variants sur l’interaction des CNTN, via les domaines immunoglobuline (Ig) 2 et 3, avec l’un de leurs ligands, le récepteur à activité tyrosine phosphatase PTPRG. Par homologie avec la structure cristallographique déjà résolue pour les quatre premiers domaines Ig de CNTN4 de souris, nous avons modélisé cette région pour les CNTN5 et 6 humaines, sauvages et mutées. Nous avons ainsi pu prédire que certains variants étaient susceptibles de modifier les liaisons ioniques ou l’encombrement stérique dans cette région d’interaction. L’ensemble de nos résultats démontre l’existence d’effets fonctionnels délétères de plusieurs variants rares des contactines retrouvés chez les patients atteints de TSA. La présence de ces variants rares chez des apparentés non atteints indique que les altérations des CNTN s’inscrivent dans un modèle de "multiple hit", qui propose que l’autisme puisse résulter de la combinaison de plusieurs atteintes génétiques, chacune représentant un facteur de risque à effet modéré et n’entraînant pas, à elle seule, le développement du trouble. Le séquençage d’exomes et de génomes entiers, en cours au laboratoire, permettra une meilleure compréhension de ces atteintes génétiques multiples. / Autism Spectrum Disorders (ASDs) affect one individual out of 100 and are characterised by deficits in communication and social interactions, and by restricted and repetitive behaviours. ASDs display a strong genetic component ; the first genes involved were identified in our laboratory and encode for cell-adhesion or scaffolding proteins localised at the synapse : neuroligins (NLGNs) and SHANKs. We were interested in the implication, in the ASDs, of contactins (CNTNs), a group of six neural cell-adhesion molecules of the immunoglobulin superfamily. These proteins are anchored to the plasma membrane by a glycosyl phosphatidylinositol (GPI) and can be secreted by cleavage of this anchor. They participate in various processes of neuronal development such as neurite outgrowth, axon guidance and fasciculation, and myelination. Genetic studies have suggested the involvement of contactins 4, 5 and 6 in the ASDs, but no functional study has confirmed this hypothesis. The present work combines a genetic analysis, a functional analysis on cultured primary rat cortical neurons and a structural analysis by molecular modelling. We identified several "Copy-Number Variants" (CNVs) in CNTN genes (mainly deletions affecting CNTN5 and CNTN6) and observed a trend of enrichment in patients compared to control individuals. Subsequent sequencing of CNTN5 and CNTN6 coding exons in more than 200 patients and 200 controls allowed us to identify non synonymous single-nucleotide variants (SNVs). Private variants (present only in one individual or one family) are enriched in patients compared to controls. CNVs and SNVs are inherited, mainly from unaffected parents, which suggests that impairments in contactins represent susceptibility factors for ASDs, rather than causal factors. In order to determine the functional effects of rare SNVs, we compared the effect on neuritogenesis of mutant CNTNs to that of WT CNTNs. We therefore analysed, on several hundreds of neurons per condition, the length and branching of neurites in a co-culture system with HEK cells overexpressing a CNTN protein. Most of CNTN5 and CNTN6 mutant proteins either inhibited or increased the positive effects of WT proteins. The last aim of the present study consisted in evaluating the influence of some of these variants on the interaction of CNTNs, via their immunoglobulin (Ig) domains 2 and 3, with one of their ligands, the protein tyrosine phosphatase receptor PTPRG. Using homology with the crystal structure that had already been solved for the first four Ig domains Ig of mouse CNTN4, we modelled this region for human CNTN5 and CNTN6, WT and mutated. We have thus been able to predict that some variants were likely to alter ionic bonds or steric constraints in this interaction module. Taken as a whole, our results demonstrate that several rare CNTN variants found in patients with ASD have deleterious functional effects. The presence of these rare variants in unaffected relatives indicates that CNTN impairments fit into a "multiple hit" model, according to which autism may result from the combination of several genetic defects, each being a risk factor with moderate effect but not triggering, in itself, the development of the disorder. Sequencing of exomes and whole genomes, ongoing in the laboratory, will allow better understanding of those multiple genetic impairments.
259

Methods for Teaching Students with Autism Spectrum Disorders: Evidence-Based Practices

Wheeler, John J., Mayton, Michael R., Carter, Stacy L. 13 April 2014 (has links)
Methods for Teaching Students with Autism Spectrum Disorders is the most comprehensive text available, aimed at helping pre-service and in-service teachers and related service professionals understand the importance of evidence-based practices in the education of learners with Autism Spectrum Disorders (ASD) from a family and longitudinal learning perspective. With its emphasis on the theme of family and professional partnerships and collaboration and consultation, the book includes learning aids such as suggested print and web-based resources, graphic organizers, and points for reflection; child and family vignettes, “Consider This” features, and examples of exemplary programs and practices; and the most up-to-date information and latest trends in the field. / https://dc.etsu.edu/etsu_books/1122/thumbnail.jpg
260

Video Modeling: Building Language and Social Skills in Individuals with Autism Spectrum Disorders

Johnson, Marie A.F. 14 March 2015 (has links)
No description available.

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