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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

Candidate Gene Analysis of Migraine Susceptibility Regions on Chromosome 1q and 19p

Curtain, Robert, n/a January 2006 (has links)
Migraine is a common, debilitating neurovascular disease charactensed by severe recurrent headache, nausea and vomiting, photophobia and phonophobia. It is clinically diagnosed based on criteria specified by the International Headache Society (IHS), defining two major classes of migraine: migraine with aura (MA) and migraine without aura (MO) MA sufferers experience neurovascular disturbances that precede the headache phase of an attack. Although migraine is partly influenced by environmental determinants, there is a significant genetic component, with disease heritability estimated to be up to 60% and mode of transmission multifactorial. The disorder is common with a large Dutch study reporting lifetime prevalence estimates of 33% in women and 13.3% in men, with an earlier study estimating 24% of women and 12% of men in the overall population. Mutations in various ion channel genes are responsible for neuromuscular and other neurological disorders. Inherited ion channel mutations or 'channelopathies' are increasingly found to be the cause of various neurological disorders in humans. In familial hemiplegic migraine (FHM), a rare subtype of migraine with aura, mutations in the CACNA1A gene (localised at C19p13) have been fbund (FHM1). This gene codes for the alphalA subunit of the neuronal voltage-dependent P/Q-type calcium channel. Recently a second gene, ATP1A2 (FHM2) (localised at C1q23), was implicated in some EHM families. The ATP1A2 ion channel gene, codes for the alpha2 subunit of the Na+, K+ ion ATPase pump. These findings of mutations in these genes have focused attention on central nervous system ionic channels and helped to better understand EHM pathophysiology, where the best genetic evidence providing molecular insight into migraine still comes flom the mutations detected in the rare form of migraine with aura; FHM. Migraine family studies, at the Genomic Research Centre (GRC), have utilised linkage analysis methods in providing results that have indicated suggestive linkage to the FHM1-CACNA1A region on l9p13, in a large multigenerational family (Migraine Family 1; MEl) affected with typical migraine. Also linkage studies conducted within the GRC have implicated an additional susceptibility region on chromosome 1q31, but still not ruling out a second susceptibility region on C1q23, with the possibility of there being two distinct loci, on the chromosome lq region. The focus of research in this thesis is on two main chromosomal regions, which were tested for migraine susceptibility on chromosome 1 and chromosome 19. The research involved a cross-disciplinary approach utilising association, linkage and mutation screening approaches. Allelic candidate gene studies can provide a suitable method for locating genes of small effect that contribute to complex genetic disorders, such as migraine. Family linkage studies are useful for detection of chromosomal susceptibility regions and association studies are powerful when a plausible candidate gene and a sequence variant with potential functional relevance is examined. Mutation screening studies can indicate a direct cause of disorders such as migraine, where possible sequence variants may alter the translation of proteins in genes, causing the disease. The first gene exanted on chromosome 19 was that of the Low Density Lipoprotein Receptor (LDLR) gene. The LDLR gene is a cell surface receptor that plays an important role in cholesterol homeostasis. We investigated the (TA)n polymorphism in exon 18 of the LDLR gene on chromosome l9pl3.2 performing an association analysis in 244 typical migraine affected patients, 151 suffering from migraine with aura, 96 with migraine without aura and 244 unaffected controls. The populations consisted of Caucasians only and controls were age and sex matched. The results showed no significant difference between groups for allele frequency distributions of the (TA)n polymorphism even after separation of the migraine affected individuals into subgroups of MA and MO affected patients. This is in contradiction to Mochi et al, 2003 who found a positive association of this variant with MO. Our study discusses possible differences between the two studies and extends this research by investigating circulating cholesterol levels in a migraine affected genetically-isolated population. Another gene examined on chromosome l9pl3 was the insulin receptor gene (1NSR). The aim of this study was to investigate through direct sequencing the INSR gene in DNA samples from a migraine affected family previously showing linkage to chromosome l9pl3 in an attempt to detect disease associated mutations. The insulin receptor gene (INSR) on chromosome 19pl3.3-13.2 is a gene of interest since a number of SNPs located within the gene have been implicated in migraine with (MA) and without aura (MO). Six DNA samples obtained from non-founding migraine affected members of migraine family one (MF 1) were used in this study. Genomic DNA was sequenced for the 1NSR gene in exons 1-22 and the promoter region. In the six migraine family member samples, previously reported single nucleotide polymorphisms (SNP5) were detected within two exonic DNA coding regions of the INSR gene. These SNPs, in exon 13 and 17, do not alter the normal INSR polypeptide sequence. In addition, intron 7 also revealed a DNA base sequence variation. For the 5' untranslated promoter region of the gene, no mutations were detected. In conclusion, this study detected no INSR mutations in affected members of a chromosome 19 linked migraine pedigree. Hence, migraine linkage to this chromosomal region may involve other candidate genes. The NOTCH3 gene on C19p13.2-p13.l has previously been shown to be a gene involved in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and may also be implicated in migraine as there are some symptom similarities between the two disorders. The TNFSF7 gene localised on Cl9pl3 is homologous to the ligands of the TNF receptor family, including TNF-alpha and TNF-beta, genes that have both been previously associated with migraine. This study investigated the migraine susceptibility locus at Cl9p13 studying two genes that may be involved in the disorder. The NOTCH3 gene was analysed by sequencing all exons with known CADASIL mutations in a family (MF1) that has previously been shown to be linked to Cl9pl3. The sequencing results for affected members of this pedigree proved to be negative for all known sequence variants giving rise to mutation causing amino acid changes for CADASIL. The direct sequencing results displayed that of a normal coding sequence for the NOTCH3 gene F or the TNFSF7 gene, this was investigated through SNP association analysis using a matched case-control migraine diagnosed population. Chi-square results showed non-significant P values across all populations tested against controls except for the MO subgroup which displayed a weak association with the TNFSF7 SNP (genotype, allele analysis P = 0.036, P = 0 017 respectively). Our results suggest that common migraine is not caused by any known CADASIL mutations in the NOTCH3 gene of interest however, the TNFSF7 gene displayed signs of involvement in a MO affected population, but, further studies are needed to confirm these results and to further explore a TNF receptor - migraine potential interaction. A final examination on chromosome 19 involved a case report of an extremely rare and severe form of migraine. As stated earlier Familial Hemiplegic Migraine (FHM) is a severe rare sub-type of migraine and gene mutations on chromosome 19 have been identified in the calcium channel gene CACNA1A (Cl9pl3) fOr FHM. Recently a gene mutation (S218L) for a dramatic syndrome originating from FHM, commonly named 'migraine coma', has implicated exon 5 of the CACNA1A gene. The occurrence of trivial head trauma, in FHM patients, may also be complicated by severe, sometimes even fatal, cerebral edema and coma occurring after a lucid interval. Hemiplegic migraine has also been found to be sporadic in which both forms share a similar spectrum of clinical presentations and genetic heterogeneity. The case report presented in this study enhances the involvement of the S218L CACNA1A mutation in the extremely rare disorder of minor head trauma induced migraine coma. It not only proves to be a powerful diagnostic tool in detecting cases of FHM head trauma induced coma but also for sporadic hemiplegic migraine (SHM) coma subjects. We conclude from this case study that the S218L mutation, in the CACNA1A calcium channel subunit gene, is involved in sporadic hemiplegic migraine (SHM), delayed cerebral edema and coma after minor head trauma. This thesis also involved analysis of chromosome 1 for migraine susceptibility, where FHM studies provided a foundation fOr common migraine research on chromosome 1. Studies have suggested that mutations in the CACNA1A gene on chromosome l9p cause FHM in only approximately 50% of affected pedigrees. The CACNAIA gene has previously been tested, within the Genomics Research Centre, in the common forms of migraine; however no new mutations or the FHM mutations were detected in these MA/MO affected samples. A second FHM susceptibility locus maps to chromosome 1q23 and mutations in the ATP1A2 gene have recently been implicated in two Cl-linked FHM pedigrees. As FHM is considered a rare and severe form of MA, it is possible that the chromosome 1q23 locus, and the ATP1A2 gene, may be involved in the common forms of migraine with (MA) and possibly without aura (MO). Also, we have previously reported evidence of linkage to microsatellite markers on chromosome 1q31 in a large pedigree affected predominately with MA, which suggests the possibility that there are two distinct loci for migraine susceptibility on chromosome 1. The objectives of this study were to extend our linkage analysis of chromosome lq microsatellite markers in predominantly migraine with aura pedigrees. Also, our aim was to test the novel FHM-2 ATP1A2 gene for involvement in these migraine affected pedigrees and a previous pedigree (Migraine Family 14; MF 14) showing evidence of linkage of markers to Clq31. This was performed by a chromosome 1 scan (31 markers) in 21 multiplex pedigrees affected mainly with MA. Also, the known FHM-2 ATP1A2 gene mutations were tested, by sequencing, fOr involvement in MA and MO in these pedigrees. Mutation screening by direct sequencing was also performed throughout the coding areas of the ATP1A2 gene in 3 MA individuals fiom MF14. The results of this study detected evidence for linkage in our migraine pedigrees at chromosome 1q23, to microsatellite markers spanning the ATP1A2 (FHM-2) gene. However testing of the known ATP1A2 gene mutations (for FHM) in migraine probands of pedigrees showing excess allele sharing was negative, with no mutations detected in these migraineurs. Sequencing of the entire coding areas of the gene through 3 MA affecteds from MF14, a pedigree showing significant linkage to this region, was also negative for mutations. In conclusion, this study reported that microsatellite markers on chromosome 1q23 show evidence of excess allele sharing in MA and some MO pedigrees, suggesting linkage to the common forms of migraine and the presence of a susceptibility gene in this region. The new FHM-2 (ATPIA2 gene) mutations reported by Fusco et al, 2003 do not cause migraine in probands of affected pedigrees showing excess allele sharing to markers in this genomic region. Also no mutations were detected in all exons of the ATP1A2 gene in 3 MA affected individuals from a large pedigree (MF14) showing linkage to this region. Investigation in this thesis continued on chromosome 1, with other genes being examined on C1q23, as well as the C1q31 region for a migraine susceptibility locus or gene. Previously in our laboratory, evidence for linkage was shown to migraine at C1q31 in one family predominantly affected with MA, with microsatellite markers in this region. The initial Cl study (above; ATP1A2 gene) has also provided evidence for linkage to the chromosome 1 locus 1q23, with evidence for excess allele sharing of markers in predominantly MA affected pedigrees. To further investigate both chromosome I loci, an investigation with six candidate genes that lie within the C1q23 and 1q31 regions through association analysis was undertaken. The results from this study reported non-significant chi-square results, showing P values greater than 0.05 across all SNPs (and a CA rpt) tested. An exception was the rs704326 SNP from exon 43 of the CACNA1E gene on C1q31. P values significantly less than 0.001 were obtained in the total migraine population and the MA subgroup, with similar frequency comparisons ascertained in both genotype and allele analysis. Examination through contingency table analysis of the CACNA1E flequency data indicated that the risk allele (A) was over-represented in the migraine group compared to the control group. Further comparison of the genotype data indicated a difference in frequency distributions (P less than 0 0001). Stratified analyses of migraine subtypes indicated that this association was specifically attributed to the MA subtype group. Odds ratios produced an OR of 4.14 with a 95% CI of 2.36 - 7.26 (P less than 0.0001). The positive association results obtained within the CACNA1E gene are interesting in the fact that FHM is considered to be a rare and severe form of migraine with aura (MA) and FHM-1 is caused by mutations contained within the calcium channel gene CACNA1A (localized at Cl9p13). The idea that FHM and specifically an FHM gene in the C1q31 genomic region may also contribute to susceptibility to the more common forms of migraine i e. migraine with aura, strongly supports and reinforces the idea that a common defective gene may be influencing both FHM and typical migraine. In conclusion, this thesis undertook a cross-disciplinary approach to genetic research of a complex disorder. The research involved linkage, association and mutation analysis strategies of migraine. This research implicated a specific variant on chromosome 1 and further supported the heterogeneic nature of migraine. Future directions into migraine research should involve further investigation of this specific variant and this genomic region. Such studies may aid in the development of more precise diagnosis and treatment methods for this complex disorder.
12

Examining the Link Between Emotional Childhood Abuse and Social Relationships in Midlife: The Moderating Role of the Oxytocin Receptor Gene

January 2018 (has links)
abstract: The current study examined the unique influence of emotional childhood abuse on positive and negative aspects of different types of social relationships (e.g., family, spouse/partner, and friends) in midlife and whether genetic variations of the oxytocin receptor gene (OXTR) moderated these associations. Genetic variations in OXTR are measured by single-nucleotide polymorphisms (SNPs), which have been the most substantially studied prospects for explaining individual differences in socio-behavioral phenotypes. Specifically, an SNP, rs53576, involving a guanine (G) to adenine (A) substitution located in the third intron of the OXTR has been associated with fundamental aspects of social processes and behaviors. Compared to A carriers, individuals homozygous for the G allele have enhanced social competencies and tend to elicit more positive responses from social partners, consequently increasing the overall quality of social relationships across the lifespan. However, the G allele of the OXTR has also been associated with greater social sensitivity. In the current study, conducted among a sample of 614 adults in midlife, it was shown that emotional childhood abuse was significantly associated with having less supportive and more strained relationships in midlife. Regarding supportive family relationships, the effect of emotional childhood abuse was moderated by the OXTR rs53576 polymorphism. Specifically, under conditions of more emotional abuse in childhood, individuals homozygous for the G allele had more supportive family relationships in midlife compared to A carriers. Overall, the findings suggest that genetic variations of OXTR rs53576 may be an important candidate in understanding the development of social relationship functioning within the context of negative early life experiences. / Dissertation/Thesis / Masters Thesis Psychology 2018
13

Elucidating the mechanisms of the human [alphabeta] vs. [gammadelta] lineage decision and the details of [gammadelta] thymocyte development

Chain, Jennifer Lee. January 2005 (has links) (PDF)
Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 182-199.
14

Vitamin D Receptor Gene Polymorphisms Knowledge And Breast Cancer In Texas

Egwuekwe, Ejike Roland 01 January 2019 (has links)
Breast cancer is a world health problem and is a leading cause of cancer-related death among women in the United States. However, breast cancer risks were reported to be reduced through exposure to Vitamin D through its Receptors identified as the p53 target gene. The purpose of this study was to assess the associations between VDR gene polymorphisms knowledge/awareness and decisions to reduce breast cancer risks and likelihood of mammogram screening among women in Texas. Data from survey were used. Roy adaptation model was the theoretical framework that guided this quasi- experimental, quantitative research. The dependent variables were decisions to reduce breast cancer risks and likelihood of mammogram screening. The independent variables were knowledge about VDR gene polymorphisms and exposure to vitamin D. The covariates were level of education, awareness, lifestyle, breast self-exams, mammograms, age, early menarche, late menopause, and family history of breast cancer. The chi-square test and regression analysis were used to test the stated research hypotheses and to answer the research questions. Knowledge of VDR gene polymorphisms and exposure to vitamin D were not significantly associated with breast cancer risk, ï?£2 (3, N= 250) =3.84, p > 0.05. Also, awareness of the risk factors for breast cancer was not significantly associated with decisions to go for mammogram screenings or to enroll in breast cancer risk-reduction programs, ï?£2 (3, N= 250) =1.58, p > 0.05. To advocate for the promotion of awareness of the importance of pharmacogenetic testing for VDR gene polymorphisms for early detection of breast cancer, which would help to undertake appropriate therapeutic measures in a timely manner to prevent cancer metastasis, further research is warranted.
15

Estudos dos polimorfismos dos genes da apolipoproteína E (ApoE) e do receptor de LDL (RLDL - A370T) em indivíduos jovens pertencentes ao estudo do Rio de Janeiro em seguimento de 28 Anos / Studies of gene polymorphisms of apolipoprotein E (ApoE) and LDL receptor (RLDL - A370T) in young individuals belonging to the study of Rio de Janeiro in follow-up of 28 Years

Rossana Ghessa Andrade de Freitas 23 August 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Estudos demonstram a associação de alterações da apolipoproteína E (ApoE) e do receptor do LDL (RLDL) com a ocorrência de doenças cardiovasculares e dislipidemia. O objetivo principal deste trabalho foi investigar a associação entre genótipos diferenciais da ApoE e do RLDL com a persistência de alterações de variáveis lipídicas em indivíduos jovens acompanhados há 28 anos no Estudo do Rio de Janeiro (ERJ). Através de um estudo longitudinal, tipo coorte, investigou-se 56 indivíduos (35M) em três avaliações. Em A1 (13.301.53 anos), A2 (22.091.91 anos) e A3 (31.231.99). Nas três ocasiões foi realizada avaliação clínica. Em A2 e A3 foram dosados colesterol total, HDL, LDL e triglicerídeos. Em A3 acrescentou-se o estudo dos polimorfismos genéticos da ApoE e do RLDL. Os fragmentos de interesse neste estudo foram amplificados por PCR (polymerase chain reaction) e os genótipos foram identificados através de reações de restrição. As frequências genotípicas de ApoE foram ε3/ε3 (62,5%), ε3/ε4 (25%), ε2/ε3 (5,4%) ,ε2/ε4 (5,4%) e ε4/ε4 (1,8%) e para os genótipos de RLDL foram AA (85,7%), AT (12,5%) e TT (1,8%). O genótipo ε2/ε2 não foi observado. A análise da distribuição dos genótipos de ApoE segundo a permanência de dislipidemia mostrou que todos os indivíduos com genótipo de ApoE dos tipos ε2/ε4 e ε4/ε4 mantiveram pelo menos um lípide alterado em A2 e A3 entretanto, todos os indivíduos com genótipo de ApoE do tipo ε2/ε3 não apresentaram lípides alterados em A2 e A3. Para o genótipo do RLDL não houve diferença significativa. Quando analisadas isoladamente, não foi identificado nenhum resultado significativo em A2 e/ou A3 associado a estes genótipos. O polimorfismo do gene da ApoE esteve associado à permanência de dislipidemia em indivíduos jovens acompanhados em estudo de seguimento longitudinal / Studies have shown the association of changes in the apolipoprotein E (ApoE) and LDL receptor (LDLR) with the occurrence of cardiovascular diseases and dyslipidemia. The objective of this study was to investigate the association between different ApoE genotypes and LDLR with the persistence of changes in lipid variables in young individuals followed-up 28 years in the study of Rio de Janeiro (ERJ). Through a longitudinal study cohort, 56 subjects (35M) in A1(13.30 1.53 years), A2(22.09 1.91 years) and A3(31.23 1.99) were investigated. On all three occasions clinical evaluation was conducted. In A2 and A3: total cholesterol, HDL, LDL and triglycerides. In A3 was added to the study of genetic polymorphisms of the ApoE and LDLR. The fragments of interest in this study were amplified by PCR (polymerase chain reaction) and the genotypes were identified by reaction with the restriction enzyme HhaI and HaeIII for ApoE and LDLR polymorphisms, respectively. ApoE genotypes were identified as ε3/ε3 (62.5%), ε3/ε4 (25%), ε2/ε3 (5.4%), ε2/ε4 (5.4%) and ε4/ε4 (1.8%) and the LDLR genotypes identified as AA (85.7%), AT (12.5%) and TT (1.8%). ε2/ε2 genotype was not observed. The analysis of the distribution of ApoE and LDLR genotypes according to the permanence of the dyslipidemia in the study sample showed that all individuals with the ApoE genotype ε2/ε4 and ε4/ε4 kept at least one lipid changes in A2 and A3 and all individuals ApoE genotype ε2/ε3 had not altered lipids in A2 and A3, while for RLDL genotype no difference was found. When analyzed individually, no lipid variable altered in A2 and/or A3, associated with these genotypes, were found. The ApoE gene polymorphism was associated with the permanence of dyslipidemia in young individuals in a longitudinal follow-up study
16

Freqüência de alterações na densidade mineral ósseas em pacientes com falência ovariana prematura : análise de associação com variáveis hormonais e polimorfismos do gene do receptor do FSH

Amarante, Fernanda do January 2008 (has links)
A Osteoporose é uma doença esquelética caracterizada pelo comprometimento da resistência óssea predispondo a um risco aumentado de fraturas em mulheres na pósmenopáusa e na população idosa. O processo de remodelamento ósseo é mediado pela atividade dos osteoblastos na formação e a atividade dos osteoclastos na reabsorção da matriz óssea. Entre os vários fatores que modulam o processo de ressorção óssea estão os hormônios esteróides sexuais. Desta forma, a diminuição dos estrogênios circulantes, como ocorre na menopausa e na Falência Ovariana Prematura (FOP) resulta em uma maior perda da massa óssea. A FOP é uma condição definida como a falência da função ovariana antes dos 40 anos de idade, causando amenorréia, hipogonadismo e níveis elevados de gonadotrofinas. Vários estudos têm sugerido que esta falência gonadal possa ser uma doença genética, sendo o gene do receptor do FSH (FSHR), considerado um dos principais genes candidatos. Entretanto faltam estudos consistentes capazes de avaliar a influência destas variantes genéticas sobre a densidade mineral óssea assim como o risco de osteoporose. Assim, estudou-se uma coorte de 32 mulheres com FOP acompanhadas na Unidade de Endocrinologia Ginecológica, Serviço de Endocrinologia do Hospital de Clínicas de Porto Alegre, com os objetivos de determinar a freqüência de alterações na DMO e analisar uma possível associação entre variáveis hormonais e densidade mineral óssea comparando-as com um grupo de referência composto por 80 mulheres, sendo 25 mulheres na pré-menopausa (PRE-M) e 55 mulheres na pós-menopausa (POS-M). Também foi pesquisado se a presença de polimorfismos do gene do receptor do FSH estava associada com alterações na densidade mineral óssea no grupo FOP. Variáveis clínicas e hormonais foram obtidas, assim como a densitometria óssea foi realizada em todas as pacientes de ambos grupos, porém a análise da freqüência das variantes Ala307Thr e Ser680Asn do exon 10 do gene do FSHR foi realizada somente das pacientes do grupo FOP. A densitometria óssea de cada paciente foi classificada como massa óssea normal ou baixa massa óssea (osteopenia ou osteoporose) pelos critérios da OMS. O IMC apresentou correlação positiva com a DMO do fêmur total (p<0.05). A freqüência de baixa massa óssea foi significativamente maior no grupo FOP do que no grupo POS-M (p=0,042). Entretanto, quando a análise foi controlada pelo uso ou não de terapia hormonal, os grupos não apresentaram diferença significativa. Identificou-se maior freqüência de baixa massa óssea em L1-L4 no grupo FOP (p<0,001) enquanto o grupo de referência POS-M apresentou maior freqüência de baixa massa óssea no fêmur total (p<0,001). Não houve associação entre as variantes Ala307Thr e Ser680Asn do gene do FSH e a densidade mineral óssea (DMO em g/cm2) em coluna ou fêmur total. Concluindo, o grupo de pacientes com FOP apresentou maior frequência de alteraçoes na DMO, em especial em coluna, quando comparado com o grupo de referência na pós-menopausa. Embora os polimorfismos estudados no exon 10 do gene do FSHR possam modificar a ação do FSH, estas variantes genéticas parecem não ter influência sobre a DMO das pacientes com FOP. Entretanto, estudos longitudinais são necessários para confirmar os resultados do presente estudo. / Osteoporosis is a skeletal disease characterized by impairment of bone strength predisposing to an increased risk of fractures in postmenopausal women and in the elderly population. The process of bone remodeling is mediated by the activity of osteoblasts in the formation and activity of osteoclasts in the resorption of bone matrix. One of the factors modulating bone resorption is sex steroid hormones. Thus, the decline of circulating estrogens, as occurs in menopause and in premature ovarian failure (POF) results in greater loss of bone mass, POF is a condition defined as the failure of ovarian function before the age of 40 years, causing amenorrhea, hypogonadism and high levels of gonadotropins. Several studies have suggested that this gonadal failure can be a genetic disease, and the gene of the FSH receptor (FSHR), is considered as one of the leading candidate genes. Nonetheless, there is lacking studies that could consistently assess the influence of these genetic variants on the bone mineral density and the risk of osteoporosis. Therefore, a cohort of 32 women presenting POF and being followed at the Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clinicas de Porto Alegre, was studied, with the objectives of determining the frequency of changes on BMD and analyze a possible association between hormonal variables and BMD, compared to a reference group composed of 80 women, with 25 in pre-menopausal (PRE-M) and 55 women in post-menopausal (POS-M). There was also searched if the presence of FSH receptor polymorphisms was associated with changes in the in bone mineral density in the group of POF. Clinical and hormonal variables were obtained as well as bone densitometry was performed in all patients in both groups; however, the analysis of the frequency of Ala307Thr and Ser680Asn variants of exon 10 of the gene of FSHR was performed only in the group of POF. Bone densitometry of each patient was classified as normal bone mass or low bone mass (osteopenia or osteoporosis) by the WHO criteria. BMI showed a positive correlation with BMD of the total femur (p <0.05). The frequency of low bone mass was significantly higher in the group of POF patients than in the POS-M group (p = 0042). However, when the analysis was controlled by the use of hormonal therapy, the no statistical difference was observed. A higher frequency of low bone mass in L1-L4 was identified in the POF group (p <0001) while the reference group of POS-M showed higher frequency of low bone mass in the total femur (p <0001). There was no association between the Ala307Thr and Ser680Asn variants of the FSHR gene and bone mineral density (BMD in g/cm2) in L1-L4 or in femur total. In conclusion, POF group presented a higher frequency of changes on BMD, mainly in lumbar spine, when compared to the reference POS-M group. While the studied polymorphisms in the exon 10 of the FSHR gene may modify the FSH actions, these genetic variants appear to have no influence on BMD of these patients. However, longitudinal studies are needed to confirm the results of this study.
17

Estudos dos polimorfismos dos genes da apolipoproteína E (ApoE) e do receptor de LDL (RLDL - A370T) em indivíduos jovens pertencentes ao estudo do Rio de Janeiro em seguimento de 28 Anos / Studies of gene polymorphisms of apolipoprotein E (ApoE) and LDL receptor (RLDL - A370T) in young individuals belonging to the study of Rio de Janeiro in follow-up of 28 Years

Rossana Ghessa Andrade de Freitas 23 August 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Estudos demonstram a associação de alterações da apolipoproteína E (ApoE) e do receptor do LDL (RLDL) com a ocorrência de doenças cardiovasculares e dislipidemia. O objetivo principal deste trabalho foi investigar a associação entre genótipos diferenciais da ApoE e do RLDL com a persistência de alterações de variáveis lipídicas em indivíduos jovens acompanhados há 28 anos no Estudo do Rio de Janeiro (ERJ). Através de um estudo longitudinal, tipo coorte, investigou-se 56 indivíduos (35M) em três avaliações. Em A1 (13.301.53 anos), A2 (22.091.91 anos) e A3 (31.231.99). Nas três ocasiões foi realizada avaliação clínica. Em A2 e A3 foram dosados colesterol total, HDL, LDL e triglicerídeos. Em A3 acrescentou-se o estudo dos polimorfismos genéticos da ApoE e do RLDL. Os fragmentos de interesse neste estudo foram amplificados por PCR (polymerase chain reaction) e os genótipos foram identificados através de reações de restrição. As frequências genotípicas de ApoE foram &#949;3/&#949;3 (62,5%), &#949;3/&#949;4 (25%), &#949;2/&#949;3 (5,4%) ,&#949;2/&#949;4 (5,4%) e &#949;4/&#949;4 (1,8%) e para os genótipos de RLDL foram AA (85,7%), AT (12,5%) e TT (1,8%). O genótipo &#949;2/&#949;2 não foi observado. A análise da distribuição dos genótipos de ApoE segundo a permanência de dislipidemia mostrou que todos os indivíduos com genótipo de ApoE dos tipos &#949;2/&#949;4 e &#949;4/&#949;4 mantiveram pelo menos um lípide alterado em A2 e A3 entretanto, todos os indivíduos com genótipo de ApoE do tipo &#949;2/&#949;3 não apresentaram lípides alterados em A2 e A3. Para o genótipo do RLDL não houve diferença significativa. Quando analisadas isoladamente, não foi identificado nenhum resultado significativo em A2 e/ou A3 associado a estes genótipos. O polimorfismo do gene da ApoE esteve associado à permanência de dislipidemia em indivíduos jovens acompanhados em estudo de seguimento longitudinal / Studies have shown the association of changes in the apolipoprotein E (ApoE) and LDL receptor (LDLR) with the occurrence of cardiovascular diseases and dyslipidemia. The objective of this study was to investigate the association between different ApoE genotypes and LDLR with the persistence of changes in lipid variables in young individuals followed-up 28 years in the study of Rio de Janeiro (ERJ). Through a longitudinal study cohort, 56 subjects (35M) in A1(13.30 1.53 years), A2(22.09 1.91 years) and A3(31.23 1.99) were investigated. On all three occasions clinical evaluation was conducted. In A2 and A3: total cholesterol, HDL, LDL and triglycerides. In A3 was added to the study of genetic polymorphisms of the ApoE and LDLR. The fragments of interest in this study were amplified by PCR (polymerase chain reaction) and the genotypes were identified by reaction with the restriction enzyme HhaI and HaeIII for ApoE and LDLR polymorphisms, respectively. ApoE genotypes were identified as &#949;3/&#949;3 (62.5%), &#949;3/&#949;4 (25%), &#949;2/&#949;3 (5.4%), &#949;2/&#949;4 (5.4%) and &#949;4/&#949;4 (1.8%) and the LDLR genotypes identified as AA (85.7%), AT (12.5%) and TT (1.8%). &#949;2/&#949;2 genotype was not observed. The analysis of the distribution of ApoE and LDLR genotypes according to the permanence of the dyslipidemia in the study sample showed that all individuals with the ApoE genotype &#949;2/&#949;4 and &#949;4/&#949;4 kept at least one lipid changes in A2 and A3 and all individuals ApoE genotype &#949;2/&#949;3 had not altered lipids in A2 and A3, while for RLDL genotype no difference was found. When analyzed individually, no lipid variable altered in A2 and/or A3, associated with these genotypes, were found. The ApoE gene polymorphism was associated with the permanence of dyslipidemia in young individuals in a longitudinal follow-up study
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Estudo do polimorfismo Ser49Gly do gene do receptor beta adrenérgico 1 (&#946;-adr 1) na população do estado do Rio de Janeiro, Brasil estratificada por cor da pele e ancestralidade genômica / Study of Ser49Gly polimorphism of beta-1 adrenergic receptor gene in a population sample on Rio de Janeiro state, Brazil, stratified by color of skin and genetic ancestry

Kelly Teixeira dos Santos 11 December 2012 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / As doenças cardiovasculares possuem a maior taxa de óbitos no mundo, e notavelmente nos últimos anos as pesquisas genéticas sobre as mesmas estão baseadas em estudos de associação, no qual o gene suspeito que esteja em maior frequência entre os pacientes passa a ser considerado um possível fator causal. Os polimorfismos genéticos que ocorrem no receptor beta-adrenérgico podem resultar em mudanças significativas na função do receptor, podendo acarretar fisiopatologias. Neste trabalho, o objetivo foi estimar a diversidade e a frequência do polimorfismo Ser49Gly do gene do receptor beta-adrenérgico 1 a partir de uma amostra de 188 indivíduos da população do Estado do Rio de Janeiro. As frequências também foram analisadas a partir da estratificação da amostra por critério fenotípico em função do padrão de cor da pele em (negros e não negros) ou ancestralidade genética em (afrodescendente e não afrodescendente), definida através da informação dos marcadores de ancestralidade Indels e SNP de cromossomo Y, para avaliar se os padrões de ancestralidade ou cor da pele são fundamentais para a diferenciação e distanciamento genético. Fragmentos de interesse foram amplificados por PCR (reação de cadeia de polimerase) com primers específicos para o marcador Ser49Gly e as reações de genotipagem foram realizadas com enzimas de restrição Eco0109I. Os valores da heterozigosidade variaram entre 0,25-0,50 e 0,20-0,41 nos grupos estratificados por ancestralidade e cor da pele, respectivamente. No que diz respeito à análise do equilíbrio de Hardy-Weinberg, não houve um desvio significativo na distribuição do marcador nas amostras gerais do Estado do Rio de Janeiro, ou mesmo nas amostras estratificadas. A distribuição dos alelos na amostra dos 188 indivíduos da população geral do Rio de Janeiro (AC_RJ) mostrou uma frequência de 80,30% e 19,70% para o alelo selvagem e mutado Ser49Gly, respectivamente. A comparação das análises sobre a distribuição das frequências alélicas para este marcador mostrou a ocorrência de diferenças significativas na distribuição das frequências alélicas entre negros e não negros e afrodescendentes e não afrodescendentes. A diferença significativa observada entre os negros e afrodescendentes, foi em menor grau de distanciamento. A informação obtida em relação à ancestralidade foi crucial para a obtenção dos dados sobre o aumento da variável mutada do polimorfismo Ser49Gly nas populações negras e afrodescendentes do Estado Rio de Janeiro. Tal evidência, em combinação com estudos clínicos podem contribuir para uma análise pormenorizada do padrão de susceptibilidade à doença em questão, em falhas do mecanismo deste receptor. / Cardiovascular diseases have the highest death rate in the world, and notably in recent years genetic research about them are based on association studies, in which the gene suspected to be at a higher frequency among patients is now considered a possible causal factor. Genetic polymorphisms that occur in the beta adrenergic receptor can result in significant changes in the receptor function that may trigger physiopathologies. The main aim of this study was to estimate the diversity and the frequency of Ser49Gly polymorphism of &#914;eta adrenergic 1 receptor gene in a sample of 188 individuals of the population of Rio de Janeiro. The frequencies were also analyzed from the sample stratification by phenotypic criteria due to skin color pattern (blacks and non-blacks) or by genetic ancestry (African descent and non-African descent), defined by ancestry information SNP and Indels markers from Y chromosome, to evaluate whether the ancestry criteria and/or skin color are crucial to the pattern of differentiation and genetic distance. Fragments of interest were amplified by PCR (polymerase chain reaction) with specific primers for the marker Ser49Gly and genotyping reactions performed by restriction with the enzyme Eco0109I. The values of heterozygosity ranged from 0.25 to 0.50 and 0.20 to 0.41 in the groups stratified by ancestry and skin color, respectively. Regarding the analysis of EHW, there was no significant deviation from this marker genotype distribution in Rio de Janeiro sample or even the stratified sample. The distribution of alleles in the sample of 188 individuals from the general population of Rio de Janeiro (AC_RJ) shows a frequency of 80.30% and 19.70% for the wild-type allele mutated Ser49 and Gly49, respectively. The comparison analysis showed the occurrence of significant differences in the distribution of allele frequencies of this marker between blacks and non-blacks and African descent and non-African descent. A significant difference was also observed between blacks and African descent, with a lesser degree of detachment. The information obtained in relation to ancestry was crucial for obtaining data on the increase in variable mutated polymorphism Ser49Gly in the black populations and African descent in Rio de Janeiro State. Such evidence, in combination with clinical studies may contribute to a detailed analysis of the pattern of susceptibility to disease involved in mechanism crashes of this receptor.
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Freqüência de alterações na densidade mineral ósseas em pacientes com falência ovariana prematura : análise de associação com variáveis hormonais e polimorfismos do gene do receptor do FSH

Amarante, Fernanda do January 2008 (has links)
A Osteoporose é uma doença esquelética caracterizada pelo comprometimento da resistência óssea predispondo a um risco aumentado de fraturas em mulheres na pósmenopáusa e na população idosa. O processo de remodelamento ósseo é mediado pela atividade dos osteoblastos na formação e a atividade dos osteoclastos na reabsorção da matriz óssea. Entre os vários fatores que modulam o processo de ressorção óssea estão os hormônios esteróides sexuais. Desta forma, a diminuição dos estrogênios circulantes, como ocorre na menopausa e na Falência Ovariana Prematura (FOP) resulta em uma maior perda da massa óssea. A FOP é uma condição definida como a falência da função ovariana antes dos 40 anos de idade, causando amenorréia, hipogonadismo e níveis elevados de gonadotrofinas. Vários estudos têm sugerido que esta falência gonadal possa ser uma doença genética, sendo o gene do receptor do FSH (FSHR), considerado um dos principais genes candidatos. Entretanto faltam estudos consistentes capazes de avaliar a influência destas variantes genéticas sobre a densidade mineral óssea assim como o risco de osteoporose. Assim, estudou-se uma coorte de 32 mulheres com FOP acompanhadas na Unidade de Endocrinologia Ginecológica, Serviço de Endocrinologia do Hospital de Clínicas de Porto Alegre, com os objetivos de determinar a freqüência de alterações na DMO e analisar uma possível associação entre variáveis hormonais e densidade mineral óssea comparando-as com um grupo de referência composto por 80 mulheres, sendo 25 mulheres na pré-menopausa (PRE-M) e 55 mulheres na pós-menopausa (POS-M). Também foi pesquisado se a presença de polimorfismos do gene do receptor do FSH estava associada com alterações na densidade mineral óssea no grupo FOP. Variáveis clínicas e hormonais foram obtidas, assim como a densitometria óssea foi realizada em todas as pacientes de ambos grupos, porém a análise da freqüência das variantes Ala307Thr e Ser680Asn do exon 10 do gene do FSHR foi realizada somente das pacientes do grupo FOP. A densitometria óssea de cada paciente foi classificada como massa óssea normal ou baixa massa óssea (osteopenia ou osteoporose) pelos critérios da OMS. O IMC apresentou correlação positiva com a DMO do fêmur total (p<0.05). A freqüência de baixa massa óssea foi significativamente maior no grupo FOP do que no grupo POS-M (p=0,042). Entretanto, quando a análise foi controlada pelo uso ou não de terapia hormonal, os grupos não apresentaram diferença significativa. Identificou-se maior freqüência de baixa massa óssea em L1-L4 no grupo FOP (p<0,001) enquanto o grupo de referência POS-M apresentou maior freqüência de baixa massa óssea no fêmur total (p<0,001). Não houve associação entre as variantes Ala307Thr e Ser680Asn do gene do FSH e a densidade mineral óssea (DMO em g/cm2) em coluna ou fêmur total. Concluindo, o grupo de pacientes com FOP apresentou maior frequência de alteraçoes na DMO, em especial em coluna, quando comparado com o grupo de referência na pós-menopausa. Embora os polimorfismos estudados no exon 10 do gene do FSHR possam modificar a ação do FSH, estas variantes genéticas parecem não ter influência sobre a DMO das pacientes com FOP. Entretanto, estudos longitudinais são necessários para confirmar os resultados do presente estudo. / Osteoporosis is a skeletal disease characterized by impairment of bone strength predisposing to an increased risk of fractures in postmenopausal women and in the elderly population. The process of bone remodeling is mediated by the activity of osteoblasts in the formation and activity of osteoclasts in the resorption of bone matrix. One of the factors modulating bone resorption is sex steroid hormones. Thus, the decline of circulating estrogens, as occurs in menopause and in premature ovarian failure (POF) results in greater loss of bone mass, POF is a condition defined as the failure of ovarian function before the age of 40 years, causing amenorrhea, hypogonadism and high levels of gonadotropins. Several studies have suggested that this gonadal failure can be a genetic disease, and the gene of the FSH receptor (FSHR), is considered as one of the leading candidate genes. Nonetheless, there is lacking studies that could consistently assess the influence of these genetic variants on the bone mineral density and the risk of osteoporosis. Therefore, a cohort of 32 women presenting POF and being followed at the Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clinicas de Porto Alegre, was studied, with the objectives of determining the frequency of changes on BMD and analyze a possible association between hormonal variables and BMD, compared to a reference group composed of 80 women, with 25 in pre-menopausal (PRE-M) and 55 women in post-menopausal (POS-M). There was also searched if the presence of FSH receptor polymorphisms was associated with changes in the in bone mineral density in the group of POF. Clinical and hormonal variables were obtained as well as bone densitometry was performed in all patients in both groups; however, the analysis of the frequency of Ala307Thr and Ser680Asn variants of exon 10 of the gene of FSHR was performed only in the group of POF. Bone densitometry of each patient was classified as normal bone mass or low bone mass (osteopenia or osteoporosis) by the WHO criteria. BMI showed a positive correlation with BMD of the total femur (p <0.05). The frequency of low bone mass was significantly higher in the group of POF patients than in the POS-M group (p = 0042). However, when the analysis was controlled by the use of hormonal therapy, the no statistical difference was observed. A higher frequency of low bone mass in L1-L4 was identified in the POF group (p <0001) while the reference group of POS-M showed higher frequency of low bone mass in the total femur (p <0001). There was no association between the Ala307Thr and Ser680Asn variants of the FSHR gene and bone mineral density (BMD in g/cm2) in L1-L4 or in femur total. In conclusion, POF group presented a higher frequency of changes on BMD, mainly in lumbar spine, when compared to the reference POS-M group. While the studied polymorphisms in the exon 10 of the FSHR gene may modify the FSH actions, these genetic variants appear to have no influence on BMD of these patients. However, longitudinal studies are needed to confirm the results of this study.
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Estudo do polimorfismo Ser49Gly do gene do receptor beta adrenérgico 1 (&#946;-adr 1) na população do estado do Rio de Janeiro, Brasil estratificada por cor da pele e ancestralidade genômica / Study of Ser49Gly polimorphism of beta-1 adrenergic receptor gene in a population sample on Rio de Janeiro state, Brazil, stratified by color of skin and genetic ancestry

Kelly Teixeira dos Santos 11 December 2012 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / As doenças cardiovasculares possuem a maior taxa de óbitos no mundo, e notavelmente nos últimos anos as pesquisas genéticas sobre as mesmas estão baseadas em estudos de associação, no qual o gene suspeito que esteja em maior frequência entre os pacientes passa a ser considerado um possível fator causal. Os polimorfismos genéticos que ocorrem no receptor beta-adrenérgico podem resultar em mudanças significativas na função do receptor, podendo acarretar fisiopatologias. Neste trabalho, o objetivo foi estimar a diversidade e a frequência do polimorfismo Ser49Gly do gene do receptor beta-adrenérgico 1 a partir de uma amostra de 188 indivíduos da população do Estado do Rio de Janeiro. As frequências também foram analisadas a partir da estratificação da amostra por critério fenotípico em função do padrão de cor da pele em (negros e não negros) ou ancestralidade genética em (afrodescendente e não afrodescendente), definida através da informação dos marcadores de ancestralidade Indels e SNP de cromossomo Y, para avaliar se os padrões de ancestralidade ou cor da pele são fundamentais para a diferenciação e distanciamento genético. Fragmentos de interesse foram amplificados por PCR (reação de cadeia de polimerase) com primers específicos para o marcador Ser49Gly e as reações de genotipagem foram realizadas com enzimas de restrição Eco0109I. Os valores da heterozigosidade variaram entre 0,25-0,50 e 0,20-0,41 nos grupos estratificados por ancestralidade e cor da pele, respectivamente. No que diz respeito à análise do equilíbrio de Hardy-Weinberg, não houve um desvio significativo na distribuição do marcador nas amostras gerais do Estado do Rio de Janeiro, ou mesmo nas amostras estratificadas. A distribuição dos alelos na amostra dos 188 indivíduos da população geral do Rio de Janeiro (AC_RJ) mostrou uma frequência de 80,30% e 19,70% para o alelo selvagem e mutado Ser49Gly, respectivamente. A comparação das análises sobre a distribuição das frequências alélicas para este marcador mostrou a ocorrência de diferenças significativas na distribuição das frequências alélicas entre negros e não negros e afrodescendentes e não afrodescendentes. A diferença significativa observada entre os negros e afrodescendentes, foi em menor grau de distanciamento. A informação obtida em relação à ancestralidade foi crucial para a obtenção dos dados sobre o aumento da variável mutada do polimorfismo Ser49Gly nas populações negras e afrodescendentes do Estado Rio de Janeiro. Tal evidência, em combinação com estudos clínicos podem contribuir para uma análise pormenorizada do padrão de susceptibilidade à doença em questão, em falhas do mecanismo deste receptor. / Cardiovascular diseases have the highest death rate in the world, and notably in recent years genetic research about them are based on association studies, in which the gene suspected to be at a higher frequency among patients is now considered a possible causal factor. Genetic polymorphisms that occur in the beta adrenergic receptor can result in significant changes in the receptor function that may trigger physiopathologies. The main aim of this study was to estimate the diversity and the frequency of Ser49Gly polymorphism of &#914;eta adrenergic 1 receptor gene in a sample of 188 individuals of the population of Rio de Janeiro. The frequencies were also analyzed from the sample stratification by phenotypic criteria due to skin color pattern (blacks and non-blacks) or by genetic ancestry (African descent and non-African descent), defined by ancestry information SNP and Indels markers from Y chromosome, to evaluate whether the ancestry criteria and/or skin color are crucial to the pattern of differentiation and genetic distance. Fragments of interest were amplified by PCR (polymerase chain reaction) with specific primers for the marker Ser49Gly and genotyping reactions performed by restriction with the enzyme Eco0109I. The values of heterozygosity ranged from 0.25 to 0.50 and 0.20 to 0.41 in the groups stratified by ancestry and skin color, respectively. Regarding the analysis of EHW, there was no significant deviation from this marker genotype distribution in Rio de Janeiro sample or even the stratified sample. The distribution of alleles in the sample of 188 individuals from the general population of Rio de Janeiro (AC_RJ) shows a frequency of 80.30% and 19.70% for the wild-type allele mutated Ser49 and Gly49, respectively. The comparison analysis showed the occurrence of significant differences in the distribution of allele frequencies of this marker between blacks and non-blacks and African descent and non-African descent. A significant difference was also observed between blacks and African descent, with a lesser degree of detachment. The information obtained in relation to ancestry was crucial for obtaining data on the increase in variable mutated polymorphism Ser49Gly in the black populations and African descent in Rio de Janeiro State. Such evidence, in combination with clinical studies may contribute to a detailed analysis of the pattern of susceptibility to disease involved in mechanism crashes of this receptor.

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