Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 13, 2009). Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Oct. 13, 2008). Includes bibliographical references (p. 174-183).

Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2006. / Dr. Peter A. Lane, Committee Member ; Dr. Larry V. McIntire, Committee Member ; Dr. Ronald W. Rousseau, Committee Member ; Dr. James R. Eckman, Committee Member ; Dr. Timothy M. Wick, Committee Chair.

Orientador: Eduardo Alves de Almeida / Coorientador: Claudia Regina Bonini Domingos / Banca: Gustavo Orlando Bonilla Rodriguez / Banca: Dorotéia Rossi Silva Souza / Resumo: A anemia falciforme (AF) apresenta fisiopatologia que envolve múltiplas alterações nos eritrócitos falcêmicos, episódios vasoclusivos, hemólise, ativação de mediadores inflamatórios, disfunção das células endoteliais e estresse oxidativo. Estes eventos dificultam o tratamento e culminam no desenvolvimento de manifestações como anemia, crises de dor e insuficiência de múltiplos órgãos. Portanto, o presente estudo objetivou, em portadores da AF, avaliar marcadores do estresse oxidativo e da capacidade antioxidante, correlacionando-os ao tratamento com hidroxiureia (HU), aos haplótipos da β-globina e aos polimorfismos da glutationa S-transferase (GSTT1, GSTM1 e GSTP1), em comparação com os resultados do grupo controle (GC). Os grupos estudados se compuseram de 48 indivíduos sem hemoglobinopatias (GC), pacientes com AF tratados com HU [AF (+HU), n=13] e pacientes não tratados [AF (-HU); n=15], após consentimento informado. Para a composição dos grupos utilizamos métodos citológicos, eletroforéticos, cromatográficos, moleculares e informações de prontuários. A pesquisa dos polimorfismos de GSTM1 e GSTT1 foi realizada por meio de PCR-MULTIPLEX, enquanto o polimorfismo GSTP1 por PCR-RFLP. Os parâmetros bioquímicos foram avaliados por meio de métodos espectrofotométricos [TBARS, TEAC, atividade das enzimas catalase (CAT) e GST] e cromatográficos [glutationa (GSH)]. Os níveis de Hb Fetal (Hb F) verificados no grupo AF (+HU) (10,9%) confirmaram seu já bem descrito efeito farmacológico da HU, porém, o grupo AF (-HU) também apresentou níveis elevados de Hb F (6,1%) que podem ter sido influenciados por fatores genéticos não considerados neste estudo. Encontramos maior frequência do haplótipo Bantu (48,2%), seguido pelo Benin (32,1%) e, também, haplótipo Camarões... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sickle cell anemia (SCA) shows a pathophysiology that involves multiple changes in the sickle cell erythrocytes, vaso-occlusive episodes, hemolysis, activation of inflammatory mediators, endothelial cell dysfunction and oxidative stress. These events complicate the treatment and culminate in the manifestations development such as anemia, pain crises and multiorgan dysfunction. Therefore, the aim of this study was to evaluate, in SCA patients, oxidative stress and antioxidant capacity markers, correlating them to treatment with hydroxyurea (HU), the β-globin haplotypes and glutathione S-transferase polymorphisms (GSTT1, GSTM1 and GSTP1) in comparison to a control group (CG). The groups were composed of 48 individuals without hemoglobinopathies (CG), SCA patients treated with HU [AF (+ HU), n = 13] and untreated patients [AF (-HU), n = 15], after informed consent . For the groups composition we used cytological, electrophoretic, chromatographic and molecular methods and information from medical records. The GSTM1 and GSTT1 polymorphisms study was performed by multiplex PCR, while the GSTP1 polymorphism by PCR-RFLP. Biochemical parameters were measured using spectrophotometric methods [TBARS, TEAC and catalase (CAT) and GST activities] and chromatographic method [glutathione (GSH)]. The Fetal Hb (Hb F) levels observed in the SCA (+HU) group (10.9%) confirmed their already welldescribed pharmacological effect of HU, however, the SCA (-HU) group also had high Hb F levels (6.1%) that may have been influenced by genetic factors not targeted in this study. We found a higher frequency of Bantu haplotype (48.2%), followed by Benin (32.1%) and also Cameroon haplotype, rare in our population and 19.7% of atypical haplotypes. The Bantu haplotype presence was related to higher lipid peroxidation levels in patients, but also, it confered the differential response to HU treatment... (Complete abstract click electronic access below) / Mestre

Haemoglobinopathies, which include sickle-cell anaemia (SCA) and α- and β-thalassaemia, represent some of our few unequivocal examples of human evolution. The underlying genetic mutations reflect a recurring adaptation against one of the biggest infectious disease killers of humans, Plasmodium falciparum malaria. Inheritance of one copy of a sickle-cell or thalassaemic allele leads to protection against death from malaria, while two copies can result in a severe blood disorder. As a result, haemoglobinopathies have risen in frequency through balancing selection and pose a significant public health problem in parts of the world with a history of malaria transmission. Their study therefore lies at the interface between evolutionary biology and public health. In this thesis, I explore different aspects of the epidemiology and population genetics of haemoglobinopathies around the world. Using pre-existing epidemiological data, statistical and geostatistical methods and Geographic Information System tools, I develop detailed evidence-based maps of the α-thalassaemia allele frequency distribution and genetic diversity in Southeast Asia and sickle-cell allele frequency in India. Pairing these with birth data, I generate sub-national estimates of the number of newborns born with severe forms of α-thalassaemia and SCA in Thailand and India, respectively, together with uncertainty estimates. In addition, I use a flexible population genetic simulation model to explore evolutionary explanations for the contrasting spatial haplotype patterns observed for SCA and the severe form of β-thalassaemia (β0-thalassaemia) in sub-Saharan Africa and the Middle East, and resurrect a 20-year old question surrounding the genetic origin of sickle-cell. Understanding the fine-scale geographical heterogeneities in the distributions of malaria-protective haemoglobinopathies is critical for addressing basic science questions and applied public health queries. Working at the interface between evolutionary biology and public health has provided me with the opportunity to build a more complete overview of the neglected increasing public health burden that this group of human disorders represents.

This thesis explores communication with children affected by sickle cell disease about their condition from the perspectives of both children and parents. It includes three papers: A literature review, an empirical paper and a critical appraisal. Papers one and two have been prepared for submission to Social Science and Medicine and Qualitative Health Research, respectively. Paper one is a meta-synthesis of qualitative literature investigating experiences of communication from the perspective of children with sickle cell disease. A systematic literature search revealed nine relevant papers, which were synthesised by extracting findings related to communication about sickle cell disease. Children were found to receive inconsistent messages about their condition from different personal and professional groups. Communication about the prognosis of sickle cell disease and the social acceptability of the condition differed across the groups. The implications for children's understandings of their condition and their adjustment are discussed. Paper two presents an empirical study of parental communication experiences with children affected by sickle cell disease. Twelve interviews were conducted and subject to inductive thematic analysis which was applied within a contextualist epistemological framework. Parents described skills in 'coaching' their child to negotiate the various challenges associated with managing sickle cell disease. They also described ways in which they avoided challenging topics of communication such as inheritance, the risk of comorbid disease and the life-long nature of the condition. The findings suggest a need for healthcare professionals to support parents in overcoming barriers to talking about difficult topics. This may facilitate more consistent communication between parents and professionals, which has implications for improving child wellbeing and adjustment. Paper three is a reflective piece and is not intended for publication. It critically evaluates papers one and two and discusses the joint implications of the findings for research and clinical practice. Reflections on the experience of conducting a meta-synthesis and an empirical qualitative study are offered in the context of personal and professional development.

Thalassaemia and sickle cell disease (SCD) are the most widely distributed blood genetic disorders that occur at a high frequency in some populations including the Mediterranean region, parts of the Middle East, South East Asia and the Indian subcontinent. It is estimated that thalassaemia major affects 100,000 newborn every year world-wide. The high incidence of these chronic haemolytic diseases in developing countries poses a high load on the national economy because of the expensive treatment protocols and the considerably high morbidity rates of these patients. Repeated blood transfusion to keep haemoglobin above an acceptable level requires well-equipped blood banks with expensive facilities to screen, store and manipulate blood and blood products. Iron chelation therapy is an essential part of treatment to avoid or delay the deleterious effects of iron overload on different organs including the liver, heart, pancreas and endocrine glands. This inquires injecting deferoxamine subcutaneously for 12 hours daily with a special pump. Both deferoxamine and pumps are expensive and therefore not accessible for all patients. In developing countries, the majority of transfusion-dependent patients with chronic haemolytic anaemia (thalassaemia and SCD) suffer from the consequences of sub-optimal treatment. The mortality rate is still high and usually patients die before the age of 30 years. They also suffer from chronic multi-organ damage including cardiac failure, liver cirrhosis, insulin-dependent diabetes mellitus, growth and pubertal failure and many skeletal abnormalities and fractures. In developed countries the introduction of high transfusion regimes and efficient chelation therapy improved survival rates and prevented cardiac and hepatic damage. However, a majority of thalassaemic patients still have significant growth and pubertal abnormalities, bone disease and multiple endocrine disorders. In Egypt the incidence of thalassaemia major ranges between 0.1 - 0.2% which gives very high patient load on the medical services. In our University of Alexandria Children's Hospital, Alexandria, Egypt. The Haematology clinic has an average of 150 thalassaemic children registered. The same problem is encountered by me in the Royal Hospital, Muscat, Oman, with high prevalence of SCD and thalassaemia and suboptimal treatment. Because of the restricted economic resources, both hospitals adopt a low transfusion therapy (to keep haemoglobin above 9 g/dl) with IM chelation 3 times per week. With this form of sub-optimal treatment we observed that a large number of our thalassaemic children have severe growth and pubertal failure/delay, beside other hepatic, cardiac and skeletal abnormalities. In fact they constitute 40% of patients attending our Endocrinology clinic. This stimulated me to perform an extensive study to survey growth and pubertal development in theses patients (study-1) and investigate the different factors that might affect their growth and pubertal development (studies 4 through 10) a \veU as bone mass density (studies > 1,12). The frequent involvement of the liver in these patients led us to study some hepatic functions and the prevalence of transfusion-associated hepatitis B surface antigenaemia and hepatitis-C virus antibody scropositivity in relation to their linear growth (studies 2,3). We studied the nutritional intake of these patients, their intestinal absorption of D-Xylosc and 48-h stool fat content in relation to their body mass index, subcutaneous 'at thickness and mid-arm circumference (studies 4,5,9). Their defective linear growth urged us to investigate their growth hormone (GH) secretion (spontaneous nocturnal as well as after provocation) and insulin-like growth factor-I (IGF-I) and IGK-binding protein-3 (IGKBl'3) concentrations. Our findings demonstrated high prevalence of defective GH secretion in these children that necessitated imaging of their hypothalamic pituitary area. Imaging studies revealed original data about structural abnormalities in the anterior pituitary gland, different degrees of pituitary atrophy and empty sella and infiltration the gland as well as the mid-brain by hacniosidrin in thalassaemic children, the mechanism of these findings was explained (studies 4-6,10). Because of their slow growth, the presence of abnormal GH/IGF-I/BP3 axis, and structural abnormalities of the pituitary gland, the next step dealt with the response of IGF-I to exogenous GH and the clinical response of their linear growth to GH therapy for a year or more (studies 4,9). Based on the fact that these patients have high prevalence of bone pains and osteoporosis during late childhood and have high risk of spontaneous fracture thereafter, we measured their bone mass density to investigate the relation between the former and the degree of iron load, growth parameters, and different anabolic hormone concentrations in these patients (studies 11,12).

?rea de concentra??o: Interdisciplinar. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-03-20T21:11:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andre_luiz_ramos_leal.pdf: 1250496 bytes, checksum: 01bc3d4df307c586d60287c63f6ba303 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-29T14:09:21Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andre_luiz_ramos_leal.pdf: 1250496 bytes, checksum: 01bc3d4df307c586d60287c63f6ba303 (MD5) / Made available in DSpace on 2018-03-29T14:09:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andre_luiz_ramos_leal.pdf: 1250496 bytes, checksum: 01bc3d4df307c586d60287c63f6ba303 (MD5) Previous issue date: 2017 / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / Funda??o Diamantinense de Apoio ao Ensino, Pesquisa e Extens?o (FUNDAEPE) / A Anemia Falciforme tem relev?ncia clinica e epidemiol?gica por afetar uma expressiva parcela da popula??o. No Brasil ? um importante problema de sa?de p?blica. Este estudo teve como objetivo compreender a aten??o ? sa?de do usu?rio portador de Anemia Falciforme na percep??o dos profissionais da Estrat?gia Sa?de da Fam?lia de Diamantina (MG). Trata-se de um estudo explorat?rio, com abordagem qualitativa, o cen?rio foi a Estrat?gia Sa?de da Fam?lia da cidade de Diamantina, Minas Gerais (Brasil). Os participantes foram 15 profissionais, m?dicos e enfermeiros, atuantes em servi?os da Estrat?gia Sa?de da Fam?lia da zona urbana do munic?pio. Foram realizadas entrevistas semiestruturadas individuais, nas unidades de sa?de, em local reservado e em hor?rio previamente definido, entre maio e junho de 2017. Na organiza??o e an?lise dos dados, optou-se pela an?lise de conte?do, modalidade tem?tica. Os resultados evidenciaram oito categorias: 1- "O (des)conhecimento dos profissionais"; 2- "Detec??o precoce: Teste do Pezinho e eletroforese de hemoglobina"; 3- "Necessidade de capacita??o profissional"; 4- "Rede de Aten??o e Assist?ncia ? Sa?de do Usu?rio Portador de Anemia Falciforme"; 5- "Rede de cuidado"; 6- "Sistema de refer?nciamento e contrarrefer?ncia"; 7- "Agente Comunit?rio de Sa?de na aten??o a sa?de do usu?rio com Anemia Falciforme"; 8- "Orienta??o e acompanhamento familiar". Revelou-se um conhecimento limitado, restrito a um breve conceito e a alguns aspectos cl?nicos. Por se constituir em uma patologia cr?nica, ? fundamental que os profissionais de sa?de estejam devidamente capacitados para prestar assist?ncia adequada, com diagn?stico precoce e tratamento correto. Por?m, os profissionais revelaram uma situa??o inversa no presente estudo, uma vez que n?o ocorre um acompanhamento sistem?tico dos usu?rios e n?o h? integra??o no sistema de refer?ncia e contrarrefer?ncia. Tais profissionais atribuem a responsabilidade da aten??o ao usu?rio somente ao servi?o especializado. Revelou-se uma ?nfase no trabalho do agente comunit?rio de sa?de na aten??o ? sa?de do usu?rio afetado pela anemia falciforme. Todavia, a assist?ncia ?s pessoas com anemia falciforme deve privilegiar a a??o multiprofissional e multidisciplinar, e n?o ser atribu?da ou concentrada somente em um profissional. Face ? essa realidade, faz-se necess?rio que os profissionais de sa?de conhe?am o assunto e sejam habilitados para proporcionarem assist?ncia de qualidade, hol?stica e equ?nime. As defici?ncias no conhecimento dos profissionais da Estrat?gia Sa?de da Fam?lia sinalizam a necessidade de capacita??o e educa??o permanente em sa?de. ? necess?ria uma rede de assist?ncia bem organizada, estruturada, cujos servi?os sejam qualificados. Conclui-se que o atual estudo demonstrou que a assist?ncia aos usu?rios afetados pela anemia falciforme, no ?mbito da Estrat?gia Sa?de da Fam?lia, requer avan?os para que seja de melhor qualidade. Isso porque os profissionais possuem conhecimento insuficiente sobre a doen?a e a assist?ncia atribuem a responsabilidade pelo cuidado ao agente comunit?rio de sa?de e ao Hemominas, e n?o h? uma integra??o na rede de aten??o ? sa?de, entre o servi?o da Estrat?gia Sa?de da Fam?lia e o Hemominas. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Sa?de, Sociedade e Ambiente, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Sickle cell anemia is clinically and epidemiologically relevant because it affects a significant portion of the population. In Brazil it is an important public health problem. This study aimed to understand the health care of the user with Sickle Cell Anemia in the perception of the professionals of the Family Health Strategy of Diamantina (MG). It is an exploratory study, with a qualitative approach, the scenario was the Family Health Strategy of the city of Diamantina, Minas Gerais (Brazil). The participants were 15 professionals, doctors and nurses, who work in Family Health Strategy services in the urban area of the municipality. Individual semi-structured interviews were carried out in the health units, in a reserved place and at a predetermined time, between May and June 2017. In the organization and analysis of the data, we opted for content analysis, thematic modality. The results showed eight categories: 1- "The (dis) knowledge of the professionals"; 2- "Early detection: Pezinho test and hemoglobin electrophoresis"; 3- "Need for professional training"; 4- "Network of Attention and Health Care of the Patient with Sickle Cell Anemia"; 5- "Network of care"; 6- "System of reference and counter-reference"; 7- "Community Health Agent in the health care of the user with Sickle Cell Anemia"; 8- "Guidance and family accompaniment". A limited knowledge has been revealed, restricted to a brief concept and some clinical aspects. Because it is a chronic pathology, it is essential that health professionals are properly trained to provide adequate care, with early diagnosis and correct treatment. However, the professionals revealed an inverse situation in the present study, since there is no systematic monitoring of users and there is no integration in the reference and counter-referral system. Such professionals assign the responsibility of attention to the user only to the specialized service. An emphasis has been placed on the work of the community health agent in the care of the user affected by sickle cell anemia. However, care for people with sickle cell anemia should focus on multiprofessional and multidisciplinary action and should not be attributed or focused solely on a professional. Faced with this reality, it is necessary that healthcare professionals know the subject and are qualified to provide quality, holistic and equitable care. The deficiencies in the knowledge of the professionals of the Family Health Strategy indicate the need for training and permanent education in health. A well-organized, well-structured service network is needed whose services are qualified. It is concluded that the present study demonstrated that the assistance to users affected by sickle cell anemia, within the scope of the Family Health Strategy, requires advances to be of better quality. This is because professionals have insufficient knowledge about the disease and care assign responsibility for care to the community health agent and Hemominas, and there is no integration in the health care network between the Family Health Strategy service and Hemominas.

A anemia falciforme (AF) é causada por uma mutação (Glu6Val) no gene que codifica a b-globina gerando a hemoglobina S (HbS). A HbS tem a tendência a se polimerizar quando desoxigenada. Isto resulta em graves manifestações clínicas para o indivíduo homozigoto (HbSS). O traço falciforme (HbAS), geralmente assintomático, também pode apresentar dano orgânico decorrente da doença. Acredita-se que, os eritrócitos falcizados estejam sob constante estresse oxidativo e, assim, liberem produtos de degradação da HbS, que atacam a membrana eritrocitária e catalisam a destruição de hidroperóxidos lipídicos com a formação de radicais alcoxil e peroxil. O ácido alfa-lipóico (AL) um potente antioxidante via seqüestro de espécies reativas de oxigênio, interações redox com outros antioxidantes e inibição da lipoperoxidação. O objetivo deste trabalho é testar o uso do ácido lipóico como um agente antioxidante no tratamento da AF. Sessenta indivíduos foram selecionados sendo, 20 normais (HbAA), 20 traço falciformes (HbAS) e 20 falciformes (HbSS). Metade dos indivíduos foi tratada com 200mg/dia de AL e o restante com placebo. As amostras de sangue foram coletadas antes e após 3 meses de suplementação. Para padronizar a qualidade da alimentação entre os grupos durante a suplementação, cada paciente recebeu mensalmente uma cesta básica adequada às suas necessidades e à de seus familiares. As atividades de catalase, superóxido dismutase e glutationa peroxidase (CAT, SOD e GPx) foram analisadas como medida de defesa antioxidante enzimática. O dano oxidativo em proteínas e lipídios foi avaliado pelas técnicas de carbonil e malondialdeído (MDA), respectivamente. A capacidade antioxidante total foi avaliada em plasma como medida adicional de defesa antioxidante. Os resultados mostraram aumento significativo na atividade de CAT nos indivíduos AS após o tratamento com AL (p=0,007). Todos os grupos apresentaram redução significativa na atividade de GPx após o tratamento (p£ 0,05), e os resultados da SOD não foram significativos. Os níveis de MDA e de carbonil em plasma tiveram redução no grupo normal tratado com AL (p= 0,015 e 0,019, respectivamente). Este mesmo grupo mostrou também diminuição da capacidade antioxidante total (p= 0,005). Estes resultados indicam uma ação benéfica do AL nos indivíduos normais. Entretanto, a dose de AL utilizada neste estudo não mostrou ação sobre as defesas antioxidantes ou redução nos níveis de dano oxidativo na anemia falciforme. É possível que uma dose maior produzisse um efeito benéfico não só sobre parâmetros de estresse oxidativo, mas também sobre outros aspectos envolvidos na fisiopatologia desta doença. / Sickle cell disease (SCD) is caused by a mutation (Glu6Val) in the gene that encodes b-globin. The sickle hemoglobin molecule (HbS) has the tendency to polymerize when deoxygenated. This results in serious clinical manifestations for homozygous SCD patient. SCD trait (HbAS) patients usually do not exhibit any symptoms although organic damage related to the disease sometimes are present. Oxidative stress plays a significant role in the disorder's pathophysiology. Several characteristic symptoms can result from oxidative stress not only in erythrocytes but also in leucocytes and endothelial cells. Alpha–lipoic acid (ALA) is a potent antioxidant, free radicals scavenger and transition metal ions chelator. It can also recycle glutathione (GSH) and inhibit lipid peroxidation. ALA actuates in both hydrophilic phase and hydrophobic membrane portion. The objective of this study was to test ALA as an antioxidant in the SCD treatment. Sixty subjects were selected and divided in groups according to hemoglobin profile: AA (normal), AS (SC trait) and SS (SCD patient). Patients were randomized into a placebo-controlled trial and treated with either ALA (200mg) or vehicle. Blood samples were collected before the start of supplementation and after 3 months of treatment. Catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were evaluated in erythrocytes. To determinate lipid damage levels, malondialdehyde (MDA) was measured by HPLC in serum and the protein damage levels were quantified in plasma by carbonyl assay. Total antioxidant status (TAS) was evaluated as nonenzymatic antioxidant defense measurement in plasma. The results show a significative increase in CAT activity (p= 0,007) in the AS group with ALA treatment. GPx activity was decreased in all groups (p£ 0,05). SOD activity was not different in any group. After ALA treatment, AA group shows significant decrease in MDA and carbonyl levels (p= 0,015 e 0,019, respectively). Interestingly, TAS was decreased in this same group (p= 0,005). These findings demonstrate the ALA capacity to prevent membrane lipid damage in normal individuals. However, this dose was not effective to reduce damage in SCD patients or SC trait. It is possible that a higher dose could protect these patients. Thus, more studies are necessary to elucidate the ALA antioxidant effects in SCD.

142f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-05-24T13:11:05Z No. of bitstreams: 1 Elisangela Adorno.pdf: 3379043 bytes, checksum: 972521d9aae8561da326946dd4da678a (MD5) / Approved for entry into archive by Flávia Ferreira(flaviaccf@yahoo.com.br) on 2013-05-30T00:18:31Z (GMT) No. of bitstreams: 1 Elisangela Adorno.pdf: 3379043 bytes, checksum: 972521d9aae8561da326946dd4da678a (MD5) / Made available in DSpace on 2013-05-30T00:18:31Z (GMT). No. of bitstreams: 1 Elisangela Adorno.pdf: 3379043 bytes, checksum: 972521d9aae8561da326946dd4da678a (MD5) Previous issue date: 2005 / Introdução. A hemoglobina S (HbS) resulta da troca de nucleotídeo (GAG GTG) no sexto codon do gene da globina beta, levando à substituição do ácido glutâmico por valina na cadeia da globina beta. A anemia falciforme ou a homozigose para a HbS, freqüentemente apresenta manifestações clínicas heterogêneas, fortemente relacionadas aos níveis de hemoglobina fetal (HbF). Objetivo. O presente estudo investigou as características fenopíticas e os marcadores moleculares presentes em portadores da anemia falciforme de Salvador-BA, identificando seqüências gênicas potencialmente importantes para a expressão dos genes gama. Métodos. O perfil de hemoglobinas e o nível de HbF foram determinados por cromatografia líquida de alta performance (HPLC). Informações sobre o perfil clínico dos pacientes foram obtidas através da análise de prontuários. A talassemia α2 3.7Kb foi investigada pela reação em cadeia da polimerase (PCR) e os haplótipos ligados ao grupo de genes da globina berta S foram investigados por PCR e análise de sítios polimórficos utilizando endonucleases de restrição (RFLP). As regiões promotoras dos genes yG e γA e o HS2-LCR foram amplificados assimetricamente e seqüenciadas no ABI Prism 3100 prism DNA Sequencer. As análises estatísticas foram desenvolvidas no software EPI-INFO versão 6.04 e a significância foi estabelecida para p < 0.05. Resultados. Foram analisados 131 pacientes, dos quais 125 tiveram identificado o genótipo beta S, tendo sido encontrado 64 (51,2%) CAR/Ben; 36 (28,8%) Ben/Ben; 18 (14,4%) CAR/CAR; dois (1,6%) CAR/Aty;dois (1,6%) Ben/Cam; um (0,8%) CAR/Cam; um (0,8%) Car/Arabia-India e um (0,8%) Sen/Aty. A talassemia 2 3.7Kb foi estudada em 110 pacientes, onde 30 (27,3%) foram heterozigotos e dois (1,8%) homozigotos. O uso de transfusão sangüínea foi maior em pacientes com HbF menor que ou igual a 10,0% (p=0,009). Pacientes com genótipos α diferentes apresentaram diferenças para os valores de Hb (p=0,018); Ht (p=0,019); VCM (p=0,0004) e HCM (p=0,039). Os níveis de HbF foram maiores entre os pacientes Ben/Ben que entre os CAR/CAR (p=0,007) e CAR/Ben (p=0,013). A análise das seqüências do HS2-LCR de dez indivíduos demonstrou a substituição G A na posição ?10.677, presente apenas entre os portadores do haplótipo Ben com nível elevado de HbF, sugerindo uma possível associação entre este polimorfismo, a expressão dos genes γ e a síntese da HbF. A análise da região promotora do gene γG demonstrou a substituição T C na posição -157, que parece ser uma seqüência característica entre os pacientes estudados. Também foi encontrada a deleção de 4 pb na posição ?222 a ?225 no gene γG e relacionado ao haplótipo Cam. Conclusões. Os dados demonstraram um novo polimorfismo localizado no HS2-LCR e na região promotora do gene γG da globina, justificando a realização de estudos adicionais, associando os níveis de HbF, marcadores biológicos e mecanismos relacionados, visando esclarecer um possível papel no desenvolvimento do fenótipo da doença. / Salvador