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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.
1

Efeitos do polimorfismo MAOA-uVNTR nos escores de QI de adultos com Transtorno de Deficit de Atenção/Hiperatividade (TDAH)

Constantin, Pâmela Camini 19 December 2016 (has links)
Submitted by FERNANDA DA SILVA VON PORSTER (fdsvporster@univates.br) on 2017-06-29T17:28:09Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016PamelaCaminiConstantin.pdf: 801061 bytes, checksum: 752334ce003a6fefe60bbc6d19852f6e (MD5) / Approved for entry into archive by Ana Paula Lisboa Monteiro (monteiro@univates.br) on 2017-07-04T15:58:23Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016PamelaCaminiConstantin.pdf: 801061 bytes, checksum: 752334ce003a6fefe60bbc6d19852f6e (MD5) / Made available in DSpace on 2017-07-04T15:58:23Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016PamelaCaminiConstantin.pdf: 801061 bytes, checksum: 752334ce003a6fefe60bbc6d19852f6e (MD5) Previous issue date: 2017-06 / CAPES / Introdução: O transtorno de deficit de atenção e hiperatividade (TDAH) é uma desordem comportamental comum em crianças e que pode persistir na idade adulta. Ele caracteriza-se por sintomas persistentes de desatenção, hiperatividade e impulsividade. Embora as estimativas de prevalência relatadas em estudos variam, a prevalência de TDAH em crianças e adolescentes oscila de 5,9-7,1%, e resultados semelhantes são encontrados para adultos: 2,5-5,0%. Além disso, uma proporção significativa dos pacientes com TDAH também apresenta outras comorbidades associadas. Diversos estudos moleculares têm sido realizados na busca pelos genes envolvidos com o TDAH e, alguns deles, sugerem o envolvimento de variações no gene codificador da enzima monoamino oxidase A (MAOA), a qual desempenha um papel importante na regulação de componentes dos sistemas dopaminérgico e serotoninérgico. Estudos moleculares sugerem que o gene possui um papel importante em características relacionadas à impulsividade, agressividade e comportamentos aditivos. Objetivo: O objetivo principal deste estudo é avaliar a associação entre o polimorfismo MAOA-uVNTR, localizado na região promotora do gene MAOA, e o TDAH em adultos. Metodologia: As amostras foram compostas por 562 indivíduos com TDAH, diagnosticados de acordo com os critérios do DSM-4, e 638 indivíduos controles, de ambos os sexos. O polimorfismo MAOA-uVNTR foi amplificado pela técnica de reação em cadeia da polimerase (PCR) e genotipado por eletroforese em gel de poliacrilamida 6%. Resultados: Não foi detectada uma associação significativa entre o polimorfismo investigado e o TDAH. Observou-se, no entanto, um efeito do polimorfismo nos escores de quociente de inteligência (QI) estimado em homens com TDAH. Portadores do alelo de baixa atividade do polimorfismo (3 repetições) apresentaram escores de QI verbal (p= <0,0001) e QI total (p= 0,001) significativamente mais baixos, quando comparados aos indivíduos portadores dos alelos de alta atividade (3.5 e 4 repetições). Conclusão: Nossos resultados indicam que o polimorfismo MAOA-uVNTR não está associado diretamente ao TDAH. No entanto, sugerem que o mesmo possa estar envolvido com a variabilidade observada nos escores de QI de pacientes com TDAH, mais especificamente em indivíduos do sexo masculino. / Introduction: Attention deficit hyperactivity disorder (ADHD) is a common behavioral disorder in children that can persist into adulthood. ADHD is characterized by persistent symptoms of inattention and hyperactivity/impulsivity. Although the estimates of prevalence vary in some studies, the prevalence of this disorder in children and adolescents ranges from 5.9-7.1%, and similar results are found for adults: 2.5-5.0%. In addition, a significant proportion of ADHD patients present other comorbidities. Several molecular studies have been employed in the search for the genes involved in ADHD susceptibility and some of them suggest the involvement of the gene that codes for the monoamine oxidase A enzyme (MAOA), which plays an important role in the regulation of components of the dopaminergic and serotoninergic systems. Molecular studies have suggest an important for the MAOA gene in characteristics related to impulsivity, aggressiveness and additive behaviors. Objective: The main objective of this study is to evaluate the association between the MAOA-uVNTR polymorphism, located in the promoter region of the MAOA gene, and ADHD in adults. Methods: The samples were composed by 535 individuals with ADHD, diagnosed according to DSM-IV criteria, and 639 control subjects, of both genders. The MAOA-uVNTR polymorphism was amplified by the polymerase chain reaction (PCR) and genotyped by 6% polyacrylamide gel electrophoresis. Results: There was no significant association between the investigated polymorphism and ADHD. However, it was observed an effect of the polymorphism on estimated intelligence quotient (IQ) scores in men with ADHD. Carriers of the low activity allele (3 repeats) presented significantly lower verbal IQ (p < 0.001) and total IQ scores (p = 0.001) when compared to individuals with high activity alleles (3.5 and 4 repeats). Conclusion: Our results indicate that the MAOA-uVNTR polymorphism is not directly associated with ADHD. However, they suggest that MAOA may be involved in the observed variability of IQ scores of patients with ADHD, more specifically in males.
2

Family-Based Association Analysis of Alcohol Dependence in the COGA Sample and Replication in the Australian Twin-Family Study

Wang, Ke Sheng, Liu, Xuefeng, Aragam, Nagesh, Jian, Xueqiu, Mullersman, Jerald E., Liu, Yali, Pan, Yue 01 September 2011 (has links)
Family, twin, and adoption studies have indicated that genetic and environmental factors contribute to the development of alcohol dependence (AD). We conducted a low-density genome-wide association analysis to identify genetic variants influencing AD. We used 11,120 SNPs from the Affymetrix 10K Genechips genotyped in 116 Caucasian pedigrees (272 nuclear families) from Genetic Analysis Workshop 14, a subset from the Collaborative Study on the Genetics of Alcoholism (COGA). Family-based association analyses for AD were performed by the PBAT program for autosomal SNPs and by the FBAT program for X-chromosome SNPs. We identified 37 SNPs associated with AD (P < 10 -3), thirteen of which were located in known genes. The most significant association with AD was observed with SNP rs1986644 (P = 8.51 × 10 -6) at 13q22 near EDNRB gene. The next best signal was at 1q41 in USH2A (rs532342, P = 1.07 × 10 -5) and the third region was at 3q25.31 in TIPARP (rs1367311, P = 2.31 × 10 -5). Furthermore, we found support for association of MAOA gene (P = 4.14 × 10 -4 for rs979606). Six of the 37 AD associated SNPs were confirmed to be associated with AD in Australian twin-family study sample (P < 0.05). Interestingly, four SNPs in DSCAML1 at 11q23 reached the genome-wide significance (the top SNP is rs10892169 with P = 5.31 × 10 -9), while rs637547 in NKAIN2 at 6q21 showed strong association with AD (P = 5.11 × 10 -7) in the replication sample. These findings offer the potential for new insights into the pathogenesis of AD and will serve as a resource for replication in other populations to elucidate the potential role of these genetic variants in AD.
3

Foundations of variation in male aggressiveness and tolerance between chacma baboons (Papio ursinus) in Botswana and Guinea baboons (P. papio) in Senegal / Foundations of variation in male aggressiveness and tolerance between chacma baboons (Papio ursinus) in Botswana and Guinea baboons (P. papio) in Senegal

Kalbitzer, Urs 16 July 2014 (has links)
Die Fitness-limitierende Ressource für die meisten männlichen Primaten ist die unteilbare Befruchtung von Weibchen. Daher herrscht in der Regel ein aggressives Konkurrenzverhalten unter Männchen, um sich den Zugang zu fertilen Weibchen zu sichern. Jedoch zeigen Männchen unterschiedlicher Arten eine erhebliche Variation in ihrer Aggressivität. In manchen Arten kann sogar ein kooperatives Verhalten zwischen Männchen beobachten werden, das meist mit weniger angespannten und toleranteren Sozialbeziehungen verbunden ist. Die proximaten und ultimaten Ursachen für diese interspezifische Variation werden durch verschiedene Aspekte des Sozialsystems einer Art bedingt, jedoch sind die zugrundeliegenden Ursachen noch nicht vollständig geklärt. Paviane (Papio spp.) stellen ein gut geeignetes Modell dar, um die Grundlage von männlicher Aggressivität und Toleranz zu untersuchen, da die unterschiedlichen Arten dieser Gattung eine erhebliche Variation in männlichem Konkurrenzverhalten und in anderen Aspekten ihrer Sozialsysteme zeigen. Männliche Bärenpaviane (P. ursinus) im südlichen und männliche Guineapaviane (P. papio) im westlichen Afrika scheinen dabei entgegengesetzte Extrema von Aggressivität und Toleranz darzustellen. Das Ziel meiner Promotion war daher, verschiedene Aspekte der männlichen Dominanzbeziehungen in den beiden Arten zu untersuchen und zu vergleichen. Bärenpaviane leben in stabilen Gruppen mit mehreren Männchen und mehreren Weibchen, in denen geschlechtsreife Männchen in benachbarte Gruppen abwandern. Dort versuchen sie mit Hilfe von aggressivem Verhalten einen hohen Rang zu erlangen, da ihnen dieser ein Vorrecht („Priority of access“) auf fertile Weibchen verschafft und über den reproduktiven Erfolg eines Männchens bestimmt. Im Gegensatz dazu leben Guineapaviane in einer mehrschichtigen (“multi-level“) Gesellschaft, in der nahverwandte Männchen häufig in der gleichen Gruppe verbleiben. Die Sozialbeziehungen zwischen Männchen scheinen dabei vor allem durch eine niedrige Frequenz agonistischer Interaktionen und eine hohe räumliche Toleranz sowie Kooperation gekennzeichnet zu sein. Daher stellen Aggressionen in dieser Art scheinbar nicht das primäre Mittel in der Konkurrenz um den Zugang zu Weibchen dar. Bisher gab es noch keine vergleichbaren Daten, um diese Vermutung über Verhaltensunterschiede zwischen den beiden Arten zu überprüfen. Daher war ein Ziel meiner Dissertation die Aggressivität und räumliche Toleranz zwischen männlichen Bärenpavianen im Moremi Game Reserve, Botsuana, und männlichen Guineapavianen im Parc National de Niokolo Koba, Senegal, zu vergleichen. Unterschiede in männlicher Konkurrenz spiegeln sich auch in unterschiedlichen altersabhängigen Verläufen des Reproduktionserfolgs wider. Bei Primaten ist dieser Verlauf wiederum mit Variation im Testosteronspiegel verbunden. Neben diesen Langzeitverläufen wurde gezeigt, dass zusätzliche, kurzfristige Anstiege in Testosteronspiegeln ein aggressives Verhalten während der Konkurrenz um Paarungspartner fördern (‚Challenge hypothesis‘). Das zweite Ziel meiner Dissertation war daher, den Zusammenhang zwischen Testosteron und dominanzbezogener Aggression zu untersuchen, indem ich die Variation in Testosteronspiegeln in Bezug auf Alter, Aggression, und Dominanzbeziehungen analysiert habe. Die Art und Weise, wie Individuen konkurrieren, beeinflusst auch, wie physiologische Kosten (oder ‚allostatic load‘) zwischen Individuen unterschiedlichen Dominanzstatus verteilt sind. Diese Kosten spiegeln sich in inter-individuellen Differenzen in Glucocorticoidspiegeln wider. Das dritte Ziel meiner Arbeit war daher die Effekte von männlichen Sozialbeziehungen auf physiologische Kosten zu untersuchen, indem ich die Variation in Glucocorticoidspiegeln in Relation zu Dominanzstatus zwischen Bären- und Guineapavianen analysiert habe. Inter-individuelle Unterschiede in Aggressivität sind stark erblich bedingt. Daher ist zu vermuten, dass auch Unterschiede zwischen Arten eine genetische Grundlage haben. Die beiden Längenpolymorphismen 5-HTTLPR - im Gen des Serotonintransporters - und MAOALPR - im Gen der monoaminen Oxidase A - beeinflussen die Aktivität des serotonergen Neurotransmittersystems und wurden mit Variation von Aggressivität in Verbindung gebracht. Verschiedene Allele dieser beiden Loci könnten daher auch mit Artunterschieden bei Pavianen gekoppelt sein. Das vierte Ziel meiner Dissertation war daher, Allele dieser beiden Loci zwischen fünf Pavianarten zu vergleichen. Durch die Erhebung der ersten unmittelbar vergleichbaren Verhaltensdaten für männliche Bären- und Guineapaviane konnte ich zeigen, dass männliche Bärenpaviane häufiger in agonistische Interaktionen verwickelt sind als Guineapaviane. Im Gegensatz dazu zeigen Guineapaviane eine höhere räumliche Toleranz gegenüber anderen Männchen und tauschen manchmal sogar affiliatives Verhalten aus. Des Weiteren zeigten männliche Bärenpaviane konsistente Dominanzbeziehungen und eine lineare Hierarchie, während die Linearität der Hierarchien von Guineapavianen allgemein niedriger war. Diese Beobachtungen stimmen mit vorherigen Beobachtungen über männliche Sozialbeziehungen in beiden Arten überein. Dies bedeutet, dass die beiden Arten sich tatsächlich in der Intensität von männlicher Wettbewerbskonkurrenz („contest competition“) unterscheiden. In keiner der beiden Arten konnte ein Zusammenhang zwischen Testosteronspiegel und Alter oder Dominanzrang gefunden werden. Es gab jedoch einen statistischen Trend, dass in Bärenpavianen der Testosteronspiegel mit Aggressivität korreliert. Dies wurde zuvor nur in Perioden beobachtet, in denen Männchen hoher Dominanzränge von anderen Männchen herausgefordert wurden (d.h. „unstabile Perioden“). Dies war in der vorliegenden Studie nicht der Fall. Jedoch könnten eine kurz zuvor beobachtete Teilung der Gruppe und darauf folgende regelmäßige Begegnungen der beiden neu entstandenen Gruppen eine ähnliche Situation verursacht haben. In Guineapavianen waren Testosteronspiegel nicht mit der Häufigkeit von agonistischen Verhalten korreliert. Dies könnte daran liegen, dass solche Verhalten in dieser Art keine bedeutende Rolle in der Konkurrenz um Paarungsmöglichkeiten spielen. Hochrangige männliche Bärenpaviane zeigten höhere Glucocorticoidspiegel als niedrigrangigere Männchen. Auch dies wurde bei Bärenpavianen bisher nur während „unstabiler Perioden“ beobachtet und weist wieder darauf hin, dass die unübliche Teilung der Gruppe eine ähnliche Situation hervorgerufen haben kann. In Guineapavianen korrelierten Glucocorticoidspiegel nicht mit Dominanzpositionen, was die Vermutung unterstütz, dass Dominanzränge in dieser Art wenig oder keine Bedeutung haben. Ein Vergleich von 5-HTTLPR und MAOALPR Allelen zwischen fünf Arten von Pavianen lässt vermuten, dass der 5-HTTLPR-Genotyp nicht mit interspezifischer Variation im Verhalten in Verbindung steht; dieser Locus war in fast allen Arten monomorph. Ein erweiterter Vergleich zwischen mehreren Arten von Pavianartigen (Papionini) deutete aber an, dass dieser Locus während der historischen Ausbreitung von Makaken nach Asien sehr wahrscheinlich unter Selektionsdrücken stand. Die Bedeutung dieser Variation muss noch untersucht werden, könnte aber eventuell mit Unterschieden in der Umwelt der jeweiligen Arten zusammenhängen. Im Gegensatz dazu war der Locus MAOALPR polymorph und das Muster verschiedener Allele passte überwiegend mit den vermuteten Verhaltensunterschieden zwischen Pavianarten zusammen. Die beobachtete Variation in diesem Locus bietet daher eine gute Möglichkeit, um genetisch bedingte Verhaltensunterschiede zwischen verschiedenen Pavianen genauer zu untersuchen und dadurch die genetischen Grundlagen der Variation in Aggressivität bei Primaten besser zu verstehen. Zusammengefasst hat meine Dissertation grundlegende Einblicke in die proximaten Ursachen und Kosten der Unterschiede in männlicher Dominanzbeziehungen zwischen Pavianarten geliefert. Erste Daten weisen darauf hin, dass Verhaltensunterschiede in Bezug auf Aggressivität zwischen Pavianen mit dem MAOALPR-Genotyp verbunden sind. Eine Untersuchung dieses Locus im Zusammenhang mit Neurotransmitter-Aktivität und Verhalten könnte daher weitere Aufschlüsse über die proximaten Mechanismen geben, die unterschiedlichen Aggressivitätsmustern in Primaten unterliegen. Verhaltensbeobachtungen und Glucocorticoid-Messungen lassen vermuten, dass die reproduktive Strategie von männlichen Guineapavianen mit weniger „offensichtlichen“ Kosten verbunden ist. Daher könnten eine Untersuchung der Mechanismen, die den Zugang zu Weibchen bei Guineapavianen regeln, und ein Vergleich des reproduktiven Erfolgs zwischen unterschiedlichen Männchen weitere Einblicke in die Evolution von reproduktiven Strategien und damit von Aggressivitäts- und Toleranzunterschiede zwischen männlichen Primaten liefern.
4

Mechanisms Driving Human Adipose Tissue Thermogenesis in vivo and its Clinical Applications in Metabolic Health

Solivan-Rivera, Javier 22 March 2022 (has links)
For many years, adipose tissue (AT) was thought to be a tissue primarily responsible for cushioning and insulating organs. However, significant advances in knowledge have shown that AT is necessary for maintaining an optimal metabolic balance through paracrine and endocrine mechanisms. Because AT dysfunction is related with illnesses such as obesity and diabetes, it is vital to understand the mechanisms behind these pathologies to restore metabolic health. Beige AT is a unique form of fat that generates heat through uncoupling protein 1 (UCP1), has a dense neurovascular network, and is associated with enhanced metabolic health. Hence, particular emphasis has been made on unraveling the processes behind thermogenic activation and maintenance, as increasing thermogenic activity offers considerable potential for treating metabolic disorders. Activation of beige AT is dependent on norepinephrine release from sympathetic neurons upon physiological cues such as cold exposure. Studies have revealed a major role of monoamine oxidase a (MAOA)-mediated norepinephrine clearance in the maintenance of thermogenic AT. However, major limitations are still present with regards to the mechanisms of neurotransmitter clearance and their role in thermogenic regulation. The initial objective of this thesis is to evaluate the effect of human white and thermogenic adipocytes on the formation of a neurovascular network in order to maintain thermogenesis and whether MAOA plays a direct role in thermogenic control. We demonstrate that implanted human thermogenic adipocytes generate a more vascularized and innervated AT than non-thermogenic adipocytes. Additional findings revealed that MAOA is expressed in human adipocytes and that inhibiting MAOA promotes thermogenesis. The second objective of this thesis is to determine if hAdipoGel (hAG) - a decellularized AT matrix – enhances mesenchymal stem cell (MSC) proliferation and differentiation, as well as human adipocyte engraftment in vivo. We show that MSC can proliferate in hAG and differentiate effectively into white and thermogenic adipocytes. Additionally, when white adipocytes are implanted with hAG, they differentiate into a fully functioning fat graft capable of integrating with the host. Understanding the thermogenic processes of human AT, in combination with the use of a suitable decellularized matrix, can aid in the development of therapeutic treatments that boost thermogenic activity and hence metabolic health.
5

The Intersection of Genes, the Environment, and Crime and Delinquency: A Longitudinal Study of Offending

Beaver, Kevin M. January 2006 (has links)
No description available.
6

The role of genes and abuse in the etiology of offending

Vaske, Jamie 17 August 2009 (has links)
No description available.
7

Addressing Issues in the Detection of Gene-Environment Interaction Through the Study of Conduct Disorder

Prom, Elizabeth Chin 01 January 2007 (has links)
This work addresses issues in the study of gene-environment interaction (GxE) through research of conduct disorder (CD) among adolescents and extends the recent report of significant GxE and subsequent replication studies. A sub-sample of 1,299 individual participants/649 twin pairs and their parents from the Virginia Twin Study of Adolescent and Behavioral Development was used for whom Monoamine Oxidase A (MAOA) genotype, diagnosis of CD, maternal antisocial personality symptoms, and household neglect were obtained. This dissertation (1) tested for GxE by gender using MAOA and childhood adversity using multiple approaches to CD measurement and model assessment, (2) determined whether other mechanisms would explain differences in GxE by gender and (3) identified and assessed other genes and environments related to the interaction MAOA and childhood adversity. Using a multiple regression approach, a main effect of the low/low MAOA genotype remained after controlling other risk factors in females. However, the effects of GxE were modest and were removed by transforming the environmental measures. In contrast, there was no significant effect of the low activity MAOA allele in males although significant GxE was detected and remained after transformation. The sign of the interaction for males was opposite from females, indicating genetic sensitivity to childhood adversity may differ by gender. Upon further investigation, gender differences in GxE were due to genotype-sex interaction and may involve MAOA. A Markov Chain Monte Carlo approach including a genetic Item Response Theory modeled CD as a trait with continuous liability, since false detection of GxE may result from measurement. In males and females, the inclusion of GxE while controlling for the other covariates was appropriate, but was little improvement in model fit and effect sizes of GxE were small. Other candidate genes functioning in the serotonin and dopamine neurotransmitter systems were tested for interaction with MAOA to affect risk for CD. Main genetic effects of dopamine transporter genotype and MAOA in the presence of comorbidity were detected. No epistatic effects were detected. The use of random forests systematically assessed the environment and produced several interesting environments that will require more thoughtful consideration before incorporation into a model testing GxE.
8

Genetic Variation and Shared Biological Susceptibility Underlying Comorbidity in Neuropsychiatry

Palomo, Tomas, Kostrzewa, Richard M., Beninger, Richard J., Archer, Trevor 01 December 2007 (has links)
Genetic factors underlying alcoholism, substance abuse, antisocial and violent behaviour, psychosis, schizophrenia and psychopathy are emerging to implicate dopaminergic and cannabinoid, but also monoaminergic and glutamatergic systems through the maze of promoter genes and polymorphisms. Candidate gene association studies suggest the involvement of a range of genes in different disorders of CNS structure and function. Indices of comorbidity both complicate the array of gene-involvement and provide a substrate of hazardous interactivity. The putative role of the serotonin transporter gene in affective-dissociative spectrum disorders presents both plausible genetic variation and complication of comorbidity. The position of genetic variation is further complicated through ethnic, contextual and social factors that provide geometric progressions in the comordity already underlying diagnostic obstacles. The concept of shared biological susceptibilty to two or more disorder conditions of comorbidity seems a recurring observation, e.g., bipolar disorder with alcoholism or schizophrenia with alcohol/substance abuse or diabetes with schizopsychotic disorder. Several lines of evidence seem to suggest that the factors influencing variation in one set of symptoms and those affecting one or more disorders are observed to a marked extent which ought to facilitate the search for susceptibility genes in comorbid brain disorders. Identification of regional genetic factors is awaited for a more compelling outline that ought eventually to lead to greater efficacy of symptom-disorder arrangements and an augmentation of current pharmacological treatment therapies.

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