Thesis (Ph.D)--University of Tennessee Health Science Center, 2008. / Title from title page screen (viewed on January 6, 2009). Research advisor: Ann K. Cashion, Ph.D. Document formatted into pages (x, 102 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 81-88).

Thesis (M.S.)--University of Tennessee Health Sciences Center, 2005. / Spine title: Effects of sickle cell disease on growth of the craniofacial complexes. Appendices: leaves 162-414 Bibliography: leaves 145-161.

Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. Marcia L. Rosal, Florida State University, College of Visual Arts and Dance, Dept. of Art Education. Title and description from dissertation home page (viewed Jan. 31, 2005). Includes bibliographical references.

Thesis (PH.D.)--Michigan State University. Chemistry, 2008. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--Alliant International University, California School of Professional Psychology, San Francisco, 2005. / Includes bibliographical references (61-64) and abstract.

The HbS gene had a limited number of origins during history, and these can be defined by the haplotype (a set of DNA polymorphisms inherited together) of the associated β-globin gene. Five major haplotypes have been identified, and associated with different ethnic groups. These are the Arab Indian haplotype, the Benin haplotype, the Cameroonian haplotype, the Central African Republic (CAR) or Bantu haplotype, and the Senegal haplotype. The polymorphisms defining these haplotypes are associated with fetal hemoglobin, the major modifier of sickle cell disease phenotype and severity. The Arab Indian haplotype, in particular, is associated with unusually high HbF levels (20%), and a significantly less severe clinical presentation. We found a novel (C>T) SNP -68 bp 5' to HBD in this region, expressed in patients with the Arab Indian haplotype, but not sickle cell disease patients expressing other β-globin cluster haplotypes. There is evidence that this -68 (C>T) polymorphism may play a functional role in the hemoglobin expression of these patients, and its effect on globin levels and disease severity is the long-term interest of this study. A previous reporter assay in K562 cells determined that the -68 SNP was associated with decreased δ-globin gene expression. This study aims to clone the HBD region of a patient positive for this SNP into a lentiviral firefly luciferase reporter vector, for use in more physiologically accurate CD34+ erythropoietic progenitor cells. If the mutations in these β-globin gene haplotypes, such as the HBD mutation described in this study, are responsible for the protective effects seen in patients, perhaps some of these genetic locations can serve as targets for therapeutics in sickle cell disease or other blood disorders.

Sickle cell disease (SCD) is a severe hemoglobin disorder caused by co-inheritance of a single mutation in the β-globin gene of adult hemoglobin (HbA; α2β2). This alteration leads to the formation of sickle hemoglobin (HbS; α2βS2) and deformed, sickle-shaped red blood cells (RBCs). Sickle RBCs obstruct small blood vessels resulting in anemia, excruciating pain crises, organ damage, and stroke. For the millions of people affected by this disease, life expectancy is only 40-60 years of age. The only cure for SCD is hematopoietic stem cell (HSC, CD34+) transplantation, which requires a human leukocyte antigen (HLA)-matched donor. However, this option runs the risk of complications associated with graft versus host disease and infection. Before birth, individuals with SCD do well because their RBCs are filled with γ-globin containing fetal hemoglobin (HbF; α2γ2), which inhibits the formation of HbS. In fact, some SCD patients who co-inherit mutations that allow for high-level expression of HbF into adulthood are asymptomatic. This suggests that genetic modification of the patient’s own HSCs to permit HbF production would be a viable therapeutic alternative to HSC transplantation. Our work has focused on the use of lentiviral vectors to introduce an exogenous γ-globin gene or shRNA sequences designed to knockdown repressors of γ-globin, such as the zinc-finger transcription factor, BCL11A, to prevent silencing of the endogenous γ-globin genes allowing for persistent expression of HbF. Despite significant progress using both approaches, we have been unable to increase the level of HbF > 30%; a curative threshold for SCD patients who continue to produce HbF into adulthood. The goal of my project was to combine these approaches into a single lentiviral vector to achieve co-regulated, erythroid-specific expression and augmented levels of HbF. I successfully modified the insulated, erythroid-specific γ-globin vector (termed V5m3-400) to include microRNA (miR)-adapted shRNAs (or shmiRs) targeting BCL11A (based on miR-30 and miR-E architectures) in the first and second noncoding introns of the γ-globin genomic sequences. Inclusion of shmiRs had no appreciable effect on integrity of the integrated provirus or vector titer. Vector performance was initially tested using human K562 erythroleukemia cells expressing a flag-tagged version of BCL11A. In this cell line, BCL11A knockdown was significantly improved using miR-E-shRNAs due to a dramatic increase (up to 350-fold) in processing of mature shRNA sequences. The miR-E vectors also provided high-level expression of γ-globin. Erythroid-specific expression of the γ-globin transgene and BCL11A knockdown was confirmed in maturing erythroid cells derived from transduced CD34+ cells of a healthy donor resulting in a 50% increase in HbF levels compared with cells transduced with V5m3-400 as a control. While encouraging, I was unable to discriminate HbF derived from the vector-encoded versus endogenous γ-globin genes. To address this, I introduced a single base change in exon 2 of the γ-globin gene encoded by V5m3-400 such that threonine replaces isoleucine at amino acid 75 (I75T). This variant was successfully distinguished from endogenous γ-globin gene products by reverse phase high performance liquid chromatography (HPLC) in culture-differentiated erythroid cells. Based on these findings, I created compound γ-globin/shmiR-E vectors that include the I75T substitution (I75Tγ-globin/shmiR-E). Future studies will focus on testing this novel vector design in erythroid cells derived from transduced CD34+ cells of healthy donors and patients with SCD. I anticipate that this compound vector has the potential to maximize γ-globin expression and promote levels of HbF that are unlikely to be safely and effectively achieved by conventional globin gene addition or shRNA knockdown approaches alone.

Made available in DSpace on 2013-01-07T15:55:06Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 15.pdf: 2584815 bytes, checksum: 6349ee7c691ec4772382bd325a63ae85 (MD5) Previous issue date: 2007 / Analisa os estudos médicos brasileiros sobre a anemia falciforme publicados nas décadas de 1930 e 1940. Esta dissertação orienta-se pela compreensão da relação entre sangue, doença e raça no pensamento médico brasileiro dos anos de 1930 e 1940, quando a anemia falciforme era considerada uma enfermidade que se observava principalmente, pela presença de hemácias falciformes no sangue e por uma variedade de sintomas clínicos, sobretudo pela anemia. Como a freqüência desta doença era maior nos negros do que nos brancos, a anemia falciforme era qualificada geralmente como uma doença racial.

Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T19:53:58Z : No. of bitstreams: 1 torres_ls_me_sjrp.pdf: 665668 bytes, checksum: 4aaf2ab7e9956b74cfe43d4216ad0030 (MD5) / A anemia falciforme (AF) afeta milhões de pessoas em todo o mundo e está associada a altas taxas de morbidade e mortalidade. Apresenta uma série de manifestações fenotípicas, que são influenciadas por fatores genéticos e ambientais, resultando em fenótipos diversificados, e um tratamento bastante eficaz tem sido o uso de hidroxiureia (HU), que ameniza os sintomas e a necessidade de transfusão sanguínea e hospitalização. Estudos de associação de genomas já demonstraram que polimorfismos genéticos podem desempenhar influência no perfil clínico dos pacientes, assim como na resposta destes à medicação. Os polimofismos -308G/A no gene TNFA e -509C/T no gene TGFB aumentam a produção das suas respectivas citocinas que atuam principalmente em vias inflamatórias e são fortes candidatos a estarem envolvidos na ocorrência de episódios vaso-oclusivos característicos da doença. Dessa forma, o objetivo do trabalho foi verificar a frequência desses polimorfismos em portadores da AF, com e sem o uso de HU, e possível relação com a gravidade das manifestações clínicas da doença. Foram obtidas 588 amostras de sangue periférico de pacientes com doença falciforme em acompanhamento no HEMORIO. A partir destas, foram separados, aleatoriamente, 240 pacientes com AF, cujo genótipo foi confirmado por procedimentos laboratoriais clássicos e moleculares. Estes foram genotipados para os polimorfismos -308G/A (TNFA) e -509C/T (TGFB) por PCR-RFLP. Os dados hematológicos e clínicos parciais de 118, dos 240 pacientes, foram obtidos por questionário e consulta aos prontuários médicos e banco de dados. A frequência do polimorfismo -308G/A foi de 0,83 em homozigose e 17,92% em heterozigose. Para o polimorfismo -509C/T, foi de 6,25% e 48,33%, respectivamente. Não foi observada associação entre o polimorfismo -308G/A e as manifestações clínicas... (Resumo completo, clicar acesso eletrônico aba / Sickle cell anemia (SCA) affects millions of people worldwide and is associated with high morbidity and mortality. This affection shows various phenotypic manifestations, which are influenced by genetic and environmental factors, resulting in many phenotypes, and the most effective treatment has been the use of hydroxyurea (HU), which improves the symptoms and the requirement for blood transfusion and hospitalization. Genome association studies have shown that genetic polymorphisms may play role on the clinical profile of patients, as well as in response to these medications. The -308G/A and -509C/T polymorphisms, in TNFA and TGFB genes respectively, increase production of their cytokines, which act on inflammatory pathways and are strong candidates to be involved in the occurrence of vaso-occlusive episodes. The aim of this study was to determine the frequency of these polymorphisms in patients with AF, with and without HU utilization, and possible relationship with the severity of clinical manifestations of disease. We obtained 588 peripheral blood samples of patients with sickle cell disease at HEMORIO. From these, were separated at random 240 patients with AF, whose genotype was confirmed by classical and molecular laboratory procedures. They were genotyped for polymorphisms-308G/A (TNFA) and-509C/T (TGFB) by PCR-RFLP. The hematological and clinical data of 118 of the 240 patients, were obtained by questionnaire and medical records and database. The frequency of polymorphism -308G/A was 0.83% in homozygous and 17.92% in heterozygous. For the polymorphism -509C/T, was 6,25% and 48.33% respectively. No association between polymorphism -308G/A and clinical manifestations in patients was found. Concerning the polymorphism-509C/T, the mutant allele (T) proved to be a risk... (Complete abstract click electronic access below)

La drépanocytose est la première maladie génétique en France et notamment en Guadeloupe. Il s’agit d’une maladie du sang qui est due à une mutation ponctuelle au niveau du gène de la β-globine, laquelle entre dans la composition de l’hémoglobine. Ainsi les drépanocytaires ont une hémoglobine anormale appelée « HbS », contrairement à l’hémoglobine normale « HbA ». En condition de faible oxygénation, l’HbS polymérise et forme des fibres à l’intérieur des érythrocytes. Ces fibres rigidifient et fragilisent les globules rouges. Par conséquent ils peuvent bloquer la circulation à cause de leur faible déformabilité, et causer des crises vaso-occlusives douloureuses, complication caractéristique de la drépanocytose. Ce modèle physiopathologique classique a été complété par les résultats plus récents montrant l’importance du rôle des leucocytes dans l’établissement de ces obstructions. Par ailleurs, les globules rouges des drépanocytaires sont plus prompts à l’hémolyse en raison de leur fragilité. En raison de l’hémolyse exacerbée, l’hémoglobine se retrouve dans le plasma et diminue la biodisponibilité du principal vasodilatateur, le monoxyde d’azote. De plus, les globules rouges rigides et déformés entrainent activation de l’endothélium. Il en résulte dans la drépanocytose, un contexte pro-inflammatoire et pro-adhérent mais aussi pro-coagulant.Ce contexte est propice à l’activation des cellules sanguines et notamment à celle des plaquettes et des érythrocytes qui par bourgeonnement de leur membrane, émettent alors en grandes quantités, des vésicules sub-micrométriques appelées microparticules, ou MP. En l’absence de traitement curatif applicable à tous les patients drépanocytaires, nous avons décidé d’étudier le profil mais aussi le rôle des MP de patients drépanocytaires dans le but de mieux comprendre cette maladie et dans l’espoir de peut-être découvrir une nouvelle piste diagnostique ou thérapeutique.Nous avons donc montré que les patients SC ont des concentrations sanguines en MP plus importantes que les sujets AA, mais moindres que les patients SS. Etonnamment les MP SC, qu’elles soient d’origine érythrocytaire ou plaquettaire, ont aussi plus de phosphatidylsérine (PS) à leur surface que les MP SS. Ce phospholipide étant impliqué dans l’activation de la cascade de la coagulation, il serait intéressant d’évaluer l’intensité de cette activation par des MP SS ou SC. On pourrait aussi comparer ces intensités à celle induite par des MP de patients SS sous hydroxyurée. En effet nous avons aussi montré que 2 ans après avoir commencé ce traitement, les MP érythrocytaires des patients ont une taille plus importante et une exposition de la PS diminuée drastiquement.Les MP étant physiologiquement dans le sang, elles peuvent entrer en contact avec les cellules sanguines mais aussi avec l’endothélium vasculaire. Etant donné l’importance des changements que connaît cet endothélium chez les drépanocytaires (pro-adhérent, pro-inflammatoire et pro-coagulant), nous nous sommes ensuite focalisés sur l’impact des MP de drépanocytaires sur les cellules endothéliales. Ces dernières provenaient de la moelle osseuse humaine, territoire fréquemment affecté par les vaso-occlusions. Il ressort de ces travaux que les MP de patients SS et SC induisent, par rapport aux MP de sujets AA, une surexpression dose-dépendante de gènes impliqués dans l’adhérence (ICAM-1, VCAM-1, E-sélectine), dans l’inflammation (IL-6, IL-1β et CD40-I) et dans la coagulation (TF). Au niveau protéique, ICAM-1 est aussi surexprimé. En effet les MP SS induisent dès 4 heures d’incubation, une augmentation de la densité moyenne d’ICAM-1 membranaire, ainsi qu’une augmentation de la proportion de cellules exprimant cette protéine. ICAM-1 étant impliquée dans l’adhérence des leucocytes à l’endothélium (roulement, adhérence ferme et même transmigration). / Sicle cell disease (SCD) is the first genetic disease in France and more specifically in Guadeloupe. It is a blood disorder due to a point mutation in the β-globin gene. The corresponding peptide chain being a part of hemoglobin, SCD patients have an abnormal hemoglobin called “HbS”, contrary to the normal one, so called “HbA”. In hypoxic conditions, HbS forms polymers inside red blood cells (RBCs), thereby making them rigid but also fragile. Consequently, RBCs can stop blood flow due to their low deformability, and so cause a painful vaso-occlusive crisis, which is a complication characterizing SCD. This pathophysiological model has been modified by recent results showing the involvement of leukocytes in the establishing of these occlusions. Besides, sickle RBCs are more prone to hemolysis owing to their being fragile. Due to this exacerbated hemolysis, hemoglobin is released in the plasma and diminishes the bioavailability of the main vasodilator, nitrite monoxide. Moreover, rigid sickled RBCs entail endothelium activation, which results in a pro-inflammatory, a pro-adhesive and a pro-coagulant context. This latter favors blood cells activation, among which are platelets and erythrocytes that bud high quantities of submicrometric membrane vesicles called microparticles, or MPs. In the absence of curative treatment for all patients, we decided to study the profile but also the role of MPs from SCD patients to better understand this disease and hoping to find a new diagnostic or therapeutic pathway. We showed that SC patients have lower MP levels than SS patients, but higher MP levels than AA subjects. Surprisingly, we have observed that SC MPs, whether they derive from RBCs or platelets (PLTs), have higher densities of exposed phosphatidylserine (PS) than SS MPs. Since this phospholipid is involved in the activation of the coagulation cascade, it would be interesting to evaluate the intensity of this activation by SS or SC MPs. One could also compare these intensities to the one induced by MPs from SS patients under hydrocarbamide. Indeed we also showed that 2 years after the beginning of this treatment, erythrocyte-derived MP are larger and expose PS much less.As MPs are physiologically in the blood, they can interact with blood cells but also with the vascular endothelium. Given the known changes of this endothelium in SCD (pro-adhesive, pro-inflammatory and pro-coagluant), we then focused on the impact of SCD MPs on endothelial cells (ECs). These cells came from human bone marrow, a territory frequently affected by vaso-occlusions. These experiments showed that SS and SC MPs, induce, compared to AA MPs, a dose-dependent overexpression of genes involved in adherence (ICAM-1, VCAM-1, E-selectin), in inflammation (IL-6, IL-1β and CD40-I) and in coagulation (TF). At the protein level, ICAM-1 is also overexpressed. Indeed SS MPs induce within 4 hours of incubation, an increase of the mean membrane density of ICAM-1, but also an increased proportion of cells bearing this protein. As ICAM-1 is involved in leukocytes adherence to the endothelium (rolling, firm adhesion and even transmigration), SS MPs may, by triggering ICAM-1 overexpression at the endothelium surface, allow their adherence to the endothelium, thereby promoting RBC adherence and so the occlusion of the vessel and the occurring of a VOC. It would be interesting to determine which type of MP cause the overexpression of ICAM-1 and to evaluate if it is sufficient to increase in vitro adherence of leukocytes to ECs stimulated with MPs. This would allow to evaluate how important MPs are when considering the fight against sickle cell disease.