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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

The synthesis and properties of some new mesogenic materials

Nicholas, B. M. January 1985 (has links)
No description available.
2

An Inheritance and Linkage Study of 19 Factor Pairs in Barley

LeBaron, Francis Cheney 01 May 1959 (has links)
Barley, during the past three decades, has been used considerably for the study of linkage groups and character inheritance. The commercial varieties are diploids, having seven pairs of chromosomes. Six linkage groups have been established. According to studies on interchange by Kramer et al. (1954), two linkage groups, formerly designated as III and VII, may be separate arms of the same chromosome. They are now generally considered as one linkage group.
3

Identificação de mutações associadas à Síndrome Aurículo-Condilar / Identification of mutated alleles associated with Auriculo-Condylar Syndrome

Tavares, Vanessa Luiza Romanelli 07 July 2011 (has links)
A síndrome aurículo-condilar (ACS) apresenta um modelo de herança autossômica dominante e é principalmente caracterizada por malformações auriculares, articulação temporomandibular anormal e hipoplasia do côndilo e da mandíbula. Devido às estruturas acometidas, é considerada uma patologia de primeiro e segundo arcos faríngeos. Com somente alguns casos clínicos descritos na literatura, o gene causador da ACS não é conhecido. Estudos recentes de nosso grupo mapearam o primeiro lócus associado à síndrome, 1p21.1-q23.3 (família ACS1), enquanto que na segunda família estudada por nós (ACS2), não houve evidência de ligação com os marcadores desta região, sugerindo heterogeneidade genética a esta doença. Nossos principais objetivos no presente trabalho foram: identificar o gene responsável por ACS1 e mapear o lócus associado à ACS2. Para o estudo de ACS1, dada a grande extensão da região candidata, com aproximadamente 1004 genes, utilizamos uma abordagem alternativa: análise de transcriptoma durante a diferenciação condrogênica a partir de células-tronco mesenquimais para seleção e subseqüente seqüenciamento de genes candidatos. Através do estudo de expressão gênica entre controle e paciente ACS1, selecionamos e realizamos o seqüenciamento de dois genes. Não detectamos nenhuma alteração patogênica nestes genes e, portanto, é pouco provável que um destes seja responsável pela ACS1. Já na família com ACS2, através de estudo de ligação com uso de microarrays de SNP e marcadores microssatélites, mapeamos o segundo lócus associado à ACS. Estudos complementares estão sendo realizados para a identificação dos alelos causadores de ACS1 e ACS2. Estes resultados, além de sua importância para o aconselhamento genético, poderão contribuir para a compreensão do desenvolvimento embrionário das estruturas acometidas nessa síndrome. / The auriculo-condylar syndrome is an autosomal dominant disease characterized by malformed ears, abnormal temporomandibular joint and condyle and mandible hypoplasia. It is considered a syndrome of the first and second pharyngeal arches. With only a few clinical cases reported in the literature, the gene that causes ACS is not known. Recent studies from our group mapped the first locus associated to the syndrome, 1p21.1-q23.3 (ACS1 family), while in the second family studied by us (ACS2), there was no evidence of linkage with this region, suggesting genetic heterogeneity of this disease. Our main objective in this study was to identify the gene responsible for ACS1 and map the locus associated to ACS2. In the study of ACS1, given the large extent of the candidate region, with approximately 1004 genes, we used an alternative approach: transcriptome analysis during chondrogenic differentiation of stem cells of a patient and a control for screening and subsequent sequencing of candidate genes. The two genes selected through this strategy were sequenced in ACS1 patients, however, not pathogenic mutation was identified. Therefore, it is very unlikely that mutations in these genes are causative of ACS1. In the family with ACS2, through linkage study using SNP microarray and microsatellite markers, we mapped the second locus associated to ACS. Additional studies are being conducted in order to identify the alleles causing ACS1 and ACS2. These results will not only contribute to a better genetic counseling for families with ACS but they will also contribute to the understanding of the embryonic development of the structures affected in this syndrome.
4

Investigação genética de duas diferentes famílias com formas dominantes de distrofia muscular do tipo cinturas / Genetic investigation of two different families with dominant forms of limb-girdle muscular dystrophy

Licinio, Luciana de Castro Paixão 02 August 2011 (has links)
As distrofias musculares tipo cinturas (DMC) incluem um grupo heterogêneo de doenças genéticas, caracterizadas por degeneração progressiva da musculatura esquelética pélvica e escapular, cuja herança pode ser autossômica dominante (DMC1) ou autossômica recessiva (DMC2). As formas dominantes são relativamente raras, compreendendo menos que 10% dos casos. Até o momento foram mapeados 8 locos para DMC1, (DMC1A-H), onde 3 genes já foram identificados (DMC1A-C) e 17 locos para DMC2 (DMC2A-Q), onde 16 genes já foram identificados. No presente estudo, identificamos uma família uruguaia (família 1) com 11 indivíduos afetados por DMC, distribuídos em 3 gerações, com um padrão de herança autossômico dominante. Os objetivos desse trabalho foram: mapear e refinar o loco gênico associado a uma manifestação familiar de DMC1, verificar se há co-localização da região mapeada com outras formas de DMC1 descritas na literatura e, apontar genes candidatos na região mapeada e triar mutações. Foi realizado estudo de ligação, no qual mapeou-se o loco para essa doença na região 4q13-q24 com Lod score de valor máximo 4.78 para o marcador D4S414. A região foi delimitada entre os marcadores D4S392 e D4S1572. A análise da região redefiniu o loco em 4q21.22-21.23, com uma redução de 33 Mb para 4Mb. Esse loco compreende a DMC1G (família 2), descrita anteriormente pelo nosso grupo. A triagem de mutação, realizada em amostras de afetados das duas famílias, nos permitiu encontrar uma alteração Thr141Iso no exon 5 do gene FAM175A apenas nos pacientes da família 2. Essa mesma alteração foi encontrada em 1 dos 500 controles testados, o que não nos permite excluir esse gene como um candidato para DMC1G já vez que essa frequência foi inferior a 1%. O fato dessa alteração não ter sido vista na família 1 também não nos permite excluí-lo, pois foi sequenciada apenas a região exônica e a metodologia utilizada também não nos permite verificar deleções nem duplicações. Estudos mais detalhados precisam ser realizados a fim de elucidar: (1) se a alteração desse gene é a causadora dessas DMCs ou, (2) se excluído esse gene, poderia ser o responsável. / Limb girdle muscular dystrophy (LGMD) include a heterogeneous group of genetic diseases characterized by progressive degeneration of skeletal muscles of the pelvic and scapular girdles, whose inheritance may be autosomal dominant (LGMD1) or autosomal recessive (LGMD2). The dominant forms are relatively rare, comprising less than 10% of cases. So far eight loci were mapped for LGMD1 (LGMD1A-H), where three genes have been identified (LGMD1A-C) and 17 loci for LGMD2 (LGMD2A-Q), with 16 identified genes. In this study, we analised a family from Uruguay (family 1) with 12 individuals affected by LGMD, with an autosomal dominant pattern distributed in three generations. The objectives of this study were: to map and refine the gene locus associated with a familial DMC1, check for co-location of the mapped region to other forms of DMC1 described in the literature and, to point candidate genes mapped in the region and to screen mutations. A linkage study was conducted, and we mapped the locus for this disease in the region 4q13-q24 with a maximum Lod score of 4.78 for marker D4S414. The region was defined between markers D4S392 and D4S1572. The analysis of the region has redefined the locus to 4q21.22-in 21:23, a reduction from 33 Mb to 4 Mb. This site includes LGMD1G (family 2), previously described by our group. Mutation screening, performed on samples of affected pacients from both families, allowed us to find a modification Thr141Iso in exon 5 on FAM175A gene only in patients of family 2. This same alteration was found in one of the 500 controls tested but does not allow us to exclude this gene as a candidate for LGMD1G since that frequency was less than 1%. The fact that this change was not seen in a family 1 does not allow us to exclude it either because only the exonic region was sequenced and the methodology used does not allow us to detect deletions or duplications. More detailed studies should be conducted to elucidate: (1) whether the alteration found in this gene is the cause of these DMCs, or (2) if not this gene, which could be the one responsible.
5

Investigação genética de duas diferentes famílias com formas dominantes de distrofia muscular do tipo cinturas / Genetic investigation of two different families with dominant forms of limb-girdle muscular dystrophy

Luciana de Castro Paixão Licinio 02 August 2011 (has links)
As distrofias musculares tipo cinturas (DMC) incluem um grupo heterogêneo de doenças genéticas, caracterizadas por degeneração progressiva da musculatura esquelética pélvica e escapular, cuja herança pode ser autossômica dominante (DMC1) ou autossômica recessiva (DMC2). As formas dominantes são relativamente raras, compreendendo menos que 10% dos casos. Até o momento foram mapeados 8 locos para DMC1, (DMC1A-H), onde 3 genes já foram identificados (DMC1A-C) e 17 locos para DMC2 (DMC2A-Q), onde 16 genes já foram identificados. No presente estudo, identificamos uma família uruguaia (família 1) com 11 indivíduos afetados por DMC, distribuídos em 3 gerações, com um padrão de herança autossômico dominante. Os objetivos desse trabalho foram: mapear e refinar o loco gênico associado a uma manifestação familiar de DMC1, verificar se há co-localização da região mapeada com outras formas de DMC1 descritas na literatura e, apontar genes candidatos na região mapeada e triar mutações. Foi realizado estudo de ligação, no qual mapeou-se o loco para essa doença na região 4q13-q24 com Lod score de valor máximo 4.78 para o marcador D4S414. A região foi delimitada entre os marcadores D4S392 e D4S1572. A análise da região redefiniu o loco em 4q21.22-21.23, com uma redução de 33 Mb para 4Mb. Esse loco compreende a DMC1G (família 2), descrita anteriormente pelo nosso grupo. A triagem de mutação, realizada em amostras de afetados das duas famílias, nos permitiu encontrar uma alteração Thr141Iso no exon 5 do gene FAM175A apenas nos pacientes da família 2. Essa mesma alteração foi encontrada em 1 dos 500 controles testados, o que não nos permite excluir esse gene como um candidato para DMC1G já vez que essa frequência foi inferior a 1%. O fato dessa alteração não ter sido vista na família 1 também não nos permite excluí-lo, pois foi sequenciada apenas a região exônica e a metodologia utilizada também não nos permite verificar deleções nem duplicações. Estudos mais detalhados precisam ser realizados a fim de elucidar: (1) se a alteração desse gene é a causadora dessas DMCs ou, (2) se excluído esse gene, poderia ser o responsável. / Limb girdle muscular dystrophy (LGMD) include a heterogeneous group of genetic diseases characterized by progressive degeneration of skeletal muscles of the pelvic and scapular girdles, whose inheritance may be autosomal dominant (LGMD1) or autosomal recessive (LGMD2). The dominant forms are relatively rare, comprising less than 10% of cases. So far eight loci were mapped for LGMD1 (LGMD1A-H), where three genes have been identified (LGMD1A-C) and 17 loci for LGMD2 (LGMD2A-Q), with 16 identified genes. In this study, we analised a family from Uruguay (family 1) with 12 individuals affected by LGMD, with an autosomal dominant pattern distributed in three generations. The objectives of this study were: to map and refine the gene locus associated with a familial DMC1, check for co-location of the mapped region to other forms of DMC1 described in the literature and, to point candidate genes mapped in the region and to screen mutations. A linkage study was conducted, and we mapped the locus for this disease in the region 4q13-q24 with a maximum Lod score of 4.78 for marker D4S414. The region was defined between markers D4S392 and D4S1572. The analysis of the region has redefined the locus to 4q21.22-in 21:23, a reduction from 33 Mb to 4 Mb. This site includes LGMD1G (family 2), previously described by our group. Mutation screening, performed on samples of affected pacients from both families, allowed us to find a modification Thr141Iso in exon 5 on FAM175A gene only in patients of family 2. This same alteration was found in one of the 500 controls tested but does not allow us to exclude this gene as a candidate for LGMD1G since that frequency was less than 1%. The fact that this change was not seen in a family 1 does not allow us to exclude it either because only the exonic region was sequenced and the methodology used does not allow us to detect deletions or duplications. More detailed studies should be conducted to elucidate: (1) whether the alteration found in this gene is the cause of these DMCs, or (2) if not this gene, which could be the one responsible.
6

Genética de ceratocone: Estudo genético e molecular de uma família brasileira / Genetics of keratoconus: Genetical and molecular study of a Brazilian family

Besborodco, Alan 29 October 2018 (has links)
O ceratocone é uma disfunção da córnea, que geralmente manifesta-se por meio de um astigmatismo irregular e de um alto grau de miopia. O estágio avançado da doença é a principal causa de indicação da cirurgia de transplante de córnea. Certamente, trata-se de uma condição complexa, com etiologia multifatorial: fatores genéticos e ambientais estão associados para a expressão fenotípica. A maioria dos casos vistos na prática clínica são não sindrômicos (cursam sem comorbidades) e isolados, mas há uma proporção considerável de casos familiares. Foi feito um levantamento bibliográfico das principais variantes associadas ou relacionadas à doença para auxiliar na investigação. O presente projeto teve por objetivo identificar uma possível variante causal, por meio de estudo de ligação de amplitude genômica (GWLS), de uma família brasileira com 15 afetados por ceratocone, após a extração de DNA e genotipagem das amostras por microarranjo de SNP. Também foi realizado o sequenciamento de exoma do probando, visando filtrar as variantes patogênicas candidatas a explicar a doença. Foram encontradas 123 variantes suspeitas no exoma do paciente avaliado por NGS. Adicionalmente, identificou-se 3 regiões com LOD Score >1 (1p35.2-p34.3; 2q32.3-q33.2; 3q23; 5q11.2-q13.2) e uma com LOD Score>2 (19p13.11-q12). A combinação das duas metodologias permitiu a identificação de três variantes, sendo uma delas provavelmente implicada na etiologia, ainda por validar. Duas outras variantes foram excluídas / Keratoconus is a dysfunction of the cornea, which usually manifests itself through irregular astigmatism and a high degree of myopia. The advanced stage of the disease is the leading cause of indication for corneal transplant surgery. Certainly, it is a complex condition with a multifactorial etiology: genetic and environmental factors acts together to the phenotypic expression. Most of the cases seen in clinical practice are non- syndromic (with no comorbidities) and isolated, but there is a considerable proportion of familial cases. A bibliographic survey of the main variants associated or related to the disease was made to suport the investigation. The present project aimed to identify a possible causal variant by genomic amplitude binding study (GWLS) of a Brazilian family with 15 affected by keratoconus, after DNA extraction and genotyping of the samples by SNP microarray. It was also performed one exome sequencing, aiming to filter out the pathogenic candidate variants from the proband to explain the disease. 123 suspected variants were found in the patient\'s exams evaluated by NGS. In addition, 3 regions with LOD Score> 1 (1p35.2-p34.3; 2q32.3-q33.2; 3q23; 5q11.2- q13.2) and one with LOD Score> 2 (19p13.11 -q12). The combination of the two methodologies allowed the identification of three variants, one of them probably implicated in the etiology, yet to be validated. Two other variants were excluded
7

Contribution à l'étude des facteurs génétiques et environnementaux de susceptibilité aux troubles bipolaires : études du trouble bipolaire à début précoce et des traumatismes affectifs de l’enfance / Contribution to the identification of genetic and environmental susceptibility factors to bipolar disorders : early-onset subtype and childhood traumatic events studies

Etain, Bruno 23 November 2009 (has links)
Les troubles bipolaires (TB) sont des maladies psychiatriques dont le déterminisme complexe fait intervenir des facteurs génétiques et environnementaux de susceptibilité. Les efforts d’identification des facteurs génétiques ont produit des résultats discordants et les facteurs environnementaux restent mal connus. Notre équipe a contribué à identifier une forme à début précoce des TB (TB-DP), son caractère fortement familial en faisant un candidat pour faciliter l’identification de gènes de susceptibilité. Ainsi, nous avons réalisé un criblage systématique du génome dans le TB-DP suggérant une liaison avec les régions chromosomiques 2p21, 2q14, 3p14, 5q33, 7q36, 10q23, 16q23 et 20p12. Nous avons montré des associations entre le TB-DP et le gène SNAP25 (rôle dans les mécanismes d’exocytose, région 20p12) et entre les TB et le gène codant l’ASMT (rôle dans la synthèse de la mélatonine). Enfin, une étude d’association pangénomique suggère une association entre le TB-DP et deux gènes de la voie du phosphatidyl-inositol (PLEKHA5 et PLCXD3). Concernant les facteurs environnementaux, les traumatismes affectifs subis dans l’enfance (principalement les abus émotionnels) sont associés aux TB, influencent deux dimensions constitutives des TB (labilité affective et intensité des affects) et interagissent avec le 5HTTLPR pour moduler l’âge de début des troubles. Ces travaux illustrent la pertinence de se focaliser sur le TB-DP pour identifier des gènes de susceptibilité, la nécessité d’explorer plus finement les facteurs environnementaux (notamment les stress précoces) et de considérer les interactions gène-environnement afin de mieux appréhender le déterminisme complexe des TB / Bipolar disorders (BD) are psychiatric diseases with a complex determinism in which genetic and environmental susceptibility factors are involved. Attempts to identify genetic factors have produced conflicting results and environmental factors remain unknown. Early-onset bipolar disorder (EO-BD) is a clinical entity that is characterized by a strong familial aggregation ; a specific focus on this subtype might facilitate the identification of susceptibility genes. A genome-wide scan in EO-BD has suggested eight regions of linkage (chromosomal regions 2p21, 2q14, 3p14, 5q33, 7q36, 10q23, 16q23 and 20p12). We have demonstrated an association between EO-BD and the SNAP25 gene (located at 20p12 and involved in exocytosis). We have demonstrated an association between BD and the ASMT gene (involved in the synthesis of melatonin). Finally, a genome-wide association study has suggested the involvement of two phosphatidyl-inositol pathway related genes in the susceptibility to EO-BD (PLEKHA5 et PLCXD3). Concerning environmental susceptibility factors, childhood affective traumatic events (mainly emotional abuse) are associated with BD, might influence two core dimensions of BD (affective lability and affect intensity) and might interact with the serotonin transporter genelinked polymorphic region to modulate the age of onset of the disorder. These studies illustrate the relevance of focusing on the early onset subgroup of the disease to identify susceptibility genes, the need to further explore early stressors as environmental factors associated with BD and to investigate the complex relationships between these two kinds of susceptibility factors
8

Genes Associated with Alcohol Withdrawal

Wang, Kesheng, Wang, Liang 01 January 2016 (has links)
Worldwide, alcohol is the third leading risk factor for disease burden, while its harmful use leads to 2.5 million deaths every year. Alcohol dependence (AD) is a complex disease, with devastating effects on individuals, families, and society. It is estimated that 76.3 million people worldwide have suffered from alcohol use disorders (AUD), including alcohol abuse and AD. Alcohol withdrawal or alcohol withdrawal symptom (AWS) refers to a cluster of symptoms that may occur when a heavy drinker suddenly stops or significantly reduces their alcohol intake. These symptoms can start as early as 2 h after the last drink, persist for weeks, and range from mild anxiety and shakiness to severe complications, such as seizures and delirium tremens. Family, twin, and adoption studies have indicated that genetic and environmental factors and their interactions contribute to the development of AD and related phenotypes, with a heritability coefficient of more than 0.5 for AD. Whole-genome linkage and candidate gene association studies have successfully identified several chromosome regions and genes that are related to AD and AWS. Furthermore, gene expression analysis, epigenetic studies, and genome-wide association studies (GWAS) have provided regions and loci for AWS. This chapter reviews the recent findings in genetic studies of AWS.

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