Sickle cell disease (SCD) is a monogenic disorder with multi-organ involvement(1). Patients with SCD suffer from recurrent vaso-occlusive crisis (VOC) resulting from sickling of red blood cells, which is induced by polymerization of deoxy-sickle hemoglobin (HbS)(1,2). Fetal hemoglobin (HbF) can ameliorate symptoms of SCD by inhibiting deoxy-HbS polymerization(3). Hydroxyurea (HU) is approved by FDA for the treatment of SCD(4). It induces HbF synthesis through multifactorial and still not well understood mechanisms(4-7). However, approximately 5-15% of patients show no significant clinical improvement(8). Additionally, numerous patient and physician-related factors limit its utilization(9). Therefore, it is important to identify additional HbF-inducing therapeutic agents, particularly those that act by mechanisms different from HU to allow potential combination therapy in the future. Previously, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) was shown to activate γ-globin gene transcription(10). Forced overexpression of PGC-1α in erythroid progenitors obtained from Lin- cells from SCD transgenic mice induces γ-globin expression(10), suggesting that PGC-1α represents a new molecular target for potential therapeutic intervention in treating SCD. In the present study, the effect of PGC-1α upregulation in primary human CD34+ derived erythroid cells was explored; an increase in γ-globin mRNA and the percent of F-cells was observed. Through literature search, ZLN005 and SR-18292 were identified as potential PGC-1α agonists(11,12). Both compounds increase the percentage of F-cells in primary human CD34+ derived erythroid cell culture. Combined treatment with HU led to a significantly higher increase in F-cell % than the increase observed under treatment with either HU, ZLN005 or SR-18292 alone. Results from those studies add to the understanding of PGC-1α and its effects on primary human erythroid cell differentiation, maturation, and HbF induction. Additionally, the results show proof of principle for combination therapy to treat SCD patients to ameliorate their disease severity by up-regulating HbF expression. Together, the knowledge gained through these studies is novel and will potentiate the development of a new class of compounds to induce HbF synthesis in adults.

This study helps to fill a remaining knowledge gap surrounding the mechanisms and pathways that contribute to cardiomyopathies in SCD. A better understanding of the pathophysiological mechanisms could lead to more accurate therapeutic targets to improve quality of life as well as life expectancy. In this study I recapitulate cardiac dysfunction in vitro by exposing engineered mouse cardiac tissues to ANG II or the sickled microenvironment. Experimental results include gene expression profiles and oxidative stress generation. Gene expression profiles in the ANG II treated tissues indicated a pathological state with upregulation in biomarkers for inflammation, cell adhesion, wall stress and ECM related genes. Further research is being conducted using insights gained from this study which will lead to a broader understanding of the biological processes involved and potentially identify novel therapeutic targets that may ultimately improve patient outcomes.

INTRODUÇÃO: Pacientes com doenças falciformes (DF) e outras anemias hemolíticas têm prevalência aumentada de hipertensão pulmonar (HP), sendo este diagnóstico associado com maior mortalidade. O objetivo deste trabalho foi estimar a prevalência desta complicação, suas características clínicas e laboratoriais e determinar o padrão hemodinâmico ao cateterismo de artéria pulmonar. MÉTODOS: Neste estudo transversal 80 pacientes consecutivos com anemia falciforme e Sb0 talassemia foram submetidos à ecocardiografia por um único observador. Os pacientes foram avaliados clinicamente, para verificar a presença de complicações associadas à DF, realizaram um teste de caminhada e realizaram exames hematológicos e bioquímicos referentes a parâmetros de hemólise, inflamação, função hepática e renal. Foi indicada avaliação hemodinâmica, com cateterismo de artéria pulmonar (Swan-Ganz), para os pacientes com velocidade de fluxo retrógrado pela tricúspide (VRT) ³2,5m/s, detectada ao ecocardiograma. A HP foi caracterizada por pressão média da artéria pulmonar ³ 25 mmHg. Os pacientes com HP foram comparados, com relação aos mesmos parâmetros prévios, ao restante da população estudada. RESULTADOS: 40% dos pacientes (32/80) apresentaram VRT³2,5m/s, sendo indicado avaliação hemodinâmica. O grupo com VRT³2,5m/s apresentou maior média etária, maior prevalência de úlceras de perna, de proteinúria e de hepatite C, menores valores de hemoglobina e de albumina, maiores valores de uréia, de creatinina, de ácido úrico, de desidrogenase lática, de aspartato aminotransferase e de gglutamiltranspeptidase do que os do grupo VRT<2,5m/s. O grupo VRT³2,5m/s apresentou também menor distância percorrida no teste de caminhada e saturação de oxigênio mais baixa tanto em repouso quanto após a caminhada. Ao ecocardiograma, este grupo apresentou maior volume atrial direito e esquerdo. 78% dos pacientes (25/32) com indicação de cateterismo se submeteram ao procedimento e em 8 deles foi confirmada HP. Dos 8 pacientes com diagnóstico de HP, 3 apresentaram hipertensão pré-capilar e os demais apresentaram hipertensão capilar (pressão de oclusão da artéria pulmonar acima de 15 mmHg). A VRT medida pelo ecocardiograma apresentou boa correlação com a medida de pressão sistólica de artéria pulmonar aferida no cateterismo (r=0,77). Os pacientes com HP confirmada apresentaram média etária maior, menores concentrações de hemoglobina e de contagem plaquetária e maiores valores de desidrogenase lática, uréia, creatinina, ácido úrico, gglutamiltranspeptidase e ferro do que o grupo sem HP. Os indivíduos com HP tiveram pior desempenho no teste de caminhada do que o grupo sem HP. Pacientes com HP apresentaram dilatação de átrio direito e esquerdo e índice cardíaco mais elevado do que o grupo sem HP. CONCLUSÕES: Pacientes com DF têm prevalência aumentada de HP detectada pelo ecocardiograma e confirmada pelo cateterismo pulmonar. O ecocardiograma é um bom instrumento de triagem. As populações separadas de acordo com o nível de VRT ao ecocardiograma apresentam diferenças clínicas e laboratoriais, sugerindo maior taxa de hemólise nas com VRT³2,5m/s. Estas diferenças se mantêm, na maior parte das situações, quando o diagnóstico de HP é confirmado. Indivíduos com diagnóstico de HP podem ter padrões hemodinâmicos de hipertensão capilar ou pré-capilar, denotando diferentes etiologias que podem implicar em diferentes abordagens terapêuticas. / INTRODUCTION: Patients with sickle cell disease (SCD) and other haemolytic anaemia have increased prevalence of pulmonary hypertension (PH) that is related to higher mortality. The aim of this stdy was to determine the prevalence of PH and, its clinical, laboratorial and hemodynamic features. METHODS: In a crosssectional study, we evaluated 80 consecutive patients with sickle cell anemia and Sb0thalassemia who were submitted to a Doppler echocardioghraphy performed by a single observer. Clinical and laboratorial data were collected for all patients in order to verify the presence of SCD complications and to evaluate haemolysis rate, inflammation, liver and renal function. All patients performed a six-minute walk test. Patients who had peak velocity of regurgitant flow of tricuspid (Vrft) of at least 2.5 m/s were referred to pulmonary artery catheterization (Swan-Ganz). PH was defined as a mean pulmonary artery pressure ³ 25 mmHg. Clinical, laboratorial and hemodynamic data of patients with confirmed PH were compared to those data of patients without PH. RESULTS: Forty percent of patients (32/80) had Vrft ³ 2.5m/s and hemodynamic evaluation was recommended. The group of patients with Vrft³2.5 m/s had higher average age, higher prevalence of leg ulcers, proteinuria and hepatitis C, lower values of hemoglobin and albumin, higher values of urea, creatinine, uric acid, lactic dehydrogenase, aspartate aminotransferase and gglutamyltranspeptidase than the group with Vrft<2.5 m.s. The group with Vrft³2.5 m/s had poorer performance on the walk test and had lowest oxygen saturation at rest and post-exercise. On echocardiography, this group had greater right and left atrial volume. Only 78% of patients (25/32) underwent pulmonary artery catheterization and, in 8 patients PH was confirmed. Among the patients with PH, 3 had pre-capillary hypertension and 5 had post-capillary hypertension (pulmonary artery occlusion pressure above 15 mmHg). The Vrft measured by echocardiogram showed good correlation with the value of systolic pulmonary artery pressure, measured on Swan-Ganz(r=0,77). The patients with confirmed PH had higher mean age, lower levels of haemoglobin and platelet count and higher values of lactic dehydrogenase, urea, creatinine, uric acid, iron and gglutamyltranspeptidase than the group without PH. Individuals with PH had poorer performance on walk test than the group without PH. Patients with PH showed increased right and left atrium volume and higher cardiac index than the group without PH. CONCLUSIONS: Patients with SCD had increased prevalence of PH detected by Doppler echocardiography and confirmed by pulmonary catheterization. The echocardiogram was a good tool for screening. Patients who had Vrft ³ 2.5m/s exhibited clinical and laboratorial data consistent with a higher hemolysis rate than those with Vrft<2.5 m/s. Individuals diagnosed with PH may have post-capillary or pre-capillary hypertension, suggesting the existence of several etiologies and the need for different therapeutic approaches.

INTRODUÇÃO: Pacientes com doenças falciformes (DF) e outras anemias hemolíticas têm prevalência aumentada de hipertensão pulmonar (HP), sendo este diagnóstico associado com maior mortalidade. O objetivo deste trabalho foi estimar a prevalência desta complicação, suas características clínicas e laboratoriais e determinar o padrão hemodinâmico ao cateterismo de artéria pulmonar. MÉTODOS: Neste estudo transversal 80 pacientes consecutivos com anemia falciforme e Sb0 talassemia foram submetidos à ecocardiografia por um único observador. Os pacientes foram avaliados clinicamente, para verificar a presença de complicações associadas à DF, realizaram um teste de caminhada e realizaram exames hematológicos e bioquímicos referentes a parâmetros de hemólise, inflamação, função hepática e renal. Foi indicada avaliação hemodinâmica, com cateterismo de artéria pulmonar (Swan-Ganz), para os pacientes com velocidade de fluxo retrógrado pela tricúspide (VRT) ³2,5m/s, detectada ao ecocardiograma. A HP foi caracterizada por pressão média da artéria pulmonar ³ 25 mmHg. Os pacientes com HP foram comparados, com relação aos mesmos parâmetros prévios, ao restante da população estudada. RESULTADOS: 40% dos pacientes (32/80) apresentaram VRT³2,5m/s, sendo indicado avaliação hemodinâmica. O grupo com VRT³2,5m/s apresentou maior média etária, maior prevalência de úlceras de perna, de proteinúria e de hepatite C, menores valores de hemoglobina e de albumina, maiores valores de uréia, de creatinina, de ácido úrico, de desidrogenase lática, de aspartato aminotransferase e de gglutamiltranspeptidase do que os do grupo VRT<2,5m/s. O grupo VRT³2,5m/s apresentou também menor distância percorrida no teste de caminhada e saturação de oxigênio mais baixa tanto em repouso quanto após a caminhada. Ao ecocardiograma, este grupo apresentou maior volume atrial direito e esquerdo. 78% dos pacientes (25/32) com indicação de cateterismo se submeteram ao procedimento e em 8 deles foi confirmada HP. Dos 8 pacientes com diagnóstico de HP, 3 apresentaram hipertensão pré-capilar e os demais apresentaram hipertensão capilar (pressão de oclusão da artéria pulmonar acima de 15 mmHg). A VRT medida pelo ecocardiograma apresentou boa correlação com a medida de pressão sistólica de artéria pulmonar aferida no cateterismo (r=0,77). Os pacientes com HP confirmada apresentaram média etária maior, menores concentrações de hemoglobina e de contagem plaquetária e maiores valores de desidrogenase lática, uréia, creatinina, ácido úrico, gglutamiltranspeptidase e ferro do que o grupo sem HP. Os indivíduos com HP tiveram pior desempenho no teste de caminhada do que o grupo sem HP. Pacientes com HP apresentaram dilatação de átrio direito e esquerdo e índice cardíaco mais elevado do que o grupo sem HP. CONCLUSÕES: Pacientes com DF têm prevalência aumentada de HP detectada pelo ecocardiograma e confirmada pelo cateterismo pulmonar. O ecocardiograma é um bom instrumento de triagem. As populações separadas de acordo com o nível de VRT ao ecocardiograma apresentam diferenças clínicas e laboratoriais, sugerindo maior taxa de hemólise nas com VRT³2,5m/s. Estas diferenças se mantêm, na maior parte das situações, quando o diagnóstico de HP é confirmado. Indivíduos com diagnóstico de HP podem ter padrões hemodinâmicos de hipertensão capilar ou pré-capilar, denotando diferentes etiologias que podem implicar em diferentes abordagens terapêuticas. / INTRODUCTION: Patients with sickle cell disease (SCD) and other haemolytic anaemia have increased prevalence of pulmonary hypertension (PH) that is related to higher mortality. The aim of this stdy was to determine the prevalence of PH and, its clinical, laboratorial and hemodynamic features. METHODS: In a crosssectional study, we evaluated 80 consecutive patients with sickle cell anemia and Sb0thalassemia who were submitted to a Doppler echocardioghraphy performed by a single observer. Clinical and laboratorial data were collected for all patients in order to verify the presence of SCD complications and to evaluate haemolysis rate, inflammation, liver and renal function. All patients performed a six-minute walk test. Patients who had peak velocity of regurgitant flow of tricuspid (Vrft) of at least 2.5 m/s were referred to pulmonary artery catheterization (Swan-Ganz). PH was defined as a mean pulmonary artery pressure ³ 25 mmHg. Clinical, laboratorial and hemodynamic data of patients with confirmed PH were compared to those data of patients without PH. RESULTS: Forty percent of patients (32/80) had Vrft ³ 2.5m/s and hemodynamic evaluation was recommended. The group of patients with Vrft³2.5 m/s had higher average age, higher prevalence of leg ulcers, proteinuria and hepatitis C, lower values of hemoglobin and albumin, higher values of urea, creatinine, uric acid, lactic dehydrogenase, aspartate aminotransferase and gglutamyltranspeptidase than the group with Vrft<2.5 m.s. The group with Vrft³2.5 m/s had poorer performance on the walk test and had lowest oxygen saturation at rest and post-exercise. On echocardiography, this group had greater right and left atrial volume. Only 78% of patients (25/32) underwent pulmonary artery catheterization and, in 8 patients PH was confirmed. Among the patients with PH, 3 had pre-capillary hypertension and 5 had post-capillary hypertension (pulmonary artery occlusion pressure above 15 mmHg). The Vrft measured by echocardiogram showed good correlation with the value of systolic pulmonary artery pressure, measured on Swan-Ganz(r=0,77). The patients with confirmed PH had higher mean age, lower levels of haemoglobin and platelet count and higher values of lactic dehydrogenase, urea, creatinine, uric acid, iron and gglutamyltranspeptidase than the group without PH. Individuals with PH had poorer performance on walk test than the group without PH. Patients with PH showed increased right and left atrium volume and higher cardiac index than the group without PH. CONCLUSIONS: Patients with SCD had increased prevalence of PH detected by Doppler echocardiography and confirmed by pulmonary catheterization. The echocardiogram was a good tool for screening. Patients who had Vrft ³ 2.5m/s exhibited clinical and laboratorial data consistent with a higher hemolysis rate than those with Vrft<2.5 m/s. Individuals diagnosed with PH may have post-capillary or pre-capillary hypertension, suggesting the existence of several etiologies and the need for different therapeutic approaches.

An understanding of the human fetal to adult hemoglobin switch offers the potential to ameliorate β-type globin gene disorders such as sickle cell anemia and β-thalassemia through activation of the fetal γ-globin gene. Chromatin modifying complexes, including MBD2-NuRD and GATA-1/FOG-1/NuRD play a role in γ-globin gene silencing, and Mi2β (CHD4) is a critical component of NuRD complexes. In the studies presented in Chapter 2, we observed that the absence of MBD2 in a sickle cell mouse model leads to a decrease in the number of sickled cells observed in the peripheral blood, and significantly increases survival in these mice. Although further studies will be necessary to fully understand the effect of MBD2 knockout in sickle cell disease mice, absence of MBD2 appears to partially ameliorate the sickle cell anemia phenotype in vivo. In the studies presented in Chapter 3, we observed that knockdown of Mi2β relieves γ-globin gene silencing in β-YAC transgenic murine CID hematopoietic cells and in CD34+ progenitor derived human primary adult erythroid cells. We show that independent of MBD2-NuRD and GATA-1/FOG-1/NuRD, Mi2β binds directly to and positively regulates both the KLF1 and BCL11A genes, which encode transcription factors critical for γ-globin gene silencing during β-type globin gene switching. Remarkably, less than 50% knockdown of Mi2β is sufficient to significantly induce γ-globin gene expression without disrupting erythroid differentiation of primary human CD34+ progenitors. These results indicate that Mi2β is a potential target for therapeutic induction of fetal hemoglobin.

As células-tronco de pluripotência induzida (iPSC) são células geradas a partir da reprogramação de células somáticas e têm potencial para diferenciação em todos os tipos celulares do organismo adulto. A indução da diferenciação de iPSC pacienteespecífico em células hematopoéticas é uma forma de estudo da hematopoese em modelos de doenças, como a anemia falciforme, e também essencial para o desenvolvimento de terapias. O presente estudo propôs a geração de célulastronco/progenitoras hematopoéticas e progenitores eritroides in vitro a partir de iPSC derivadas de pacientes com anemia falciforme através da formação de corpos embrioides. Ao longo da diferenciação, os desenvolvimentos hematopoético e eritroide foram monitorados através de ensaios de formação de colônia e imunofenotipagem por citometria de fluxo. Neste estudo, demonstramos a presença de células com fenótipo de células endoteliais no início da diferenciação hematopoética por formação de corpos embrioides, possivelmente indicando que as células progenitoras hematopoéticas são provenientes de um endotélio hemogênico. Também verificamos a presença de células endoteliais sem potencial de endotélio hemogênico. Geramos células com características de células-tronco/progenitoras hematopoéticas, de fenótipos CD34+CD45+ e CD45+CD43+, progenitores eritroides (CD36+, CD71+ e CD235a+), bem como a formação de colônias hematopoéticas em cultura em meio semi-sólido. A linhagem de iPSC PBscd08 demonstrou maior potencial para diferenciação em células hematopoéticas e eritroide que as demais linhagens celulares avaliadas. A linhagem PBscd01, também gerada a partir de células mononucleares do sangue periférico (PBMC) de paciente com anemia falciforme, não demonstrou o mesmo potencial para a diferenciação hematopoética, gerando apenas células CD34+ e baixa porcentagem de células CD45+ e CD43+. A linhagem de iPSC PB12, gerada a partir de PBMC de indivíduo saudável, promoveu a geração de populações de células CD34+, CD45+ e CD43+, mas não duplo-positivas, e a geração de células com morfologia de células mieloides após a maturação. As linhagens celulares de iPSC demonstraram variabilidade quanto ao potencial de diferenciação hematopoética. Isto monstra a necessidade de estudos futuros para uma investigação mais detalhada. / Induced pluripotent stem cells (iPSC) are cells generated by reprogramming somatic cells, they have the potential for differentiation into all types of cells in the adult organism. The differentiation of patient-specific iPSC into hematopoietic cells is a way of studying hematopoiesis in disease models, such as sickle cell anemia, and is also essential for the development of therapies. The present study proposed the generation of hematopoietic stem/progenitor cells and erythroid progenitors from iPSC derived from patients with sickle cell anemia. Throughout the differentiation, hematopoietic and erythroid developments were monitored by colony forming cell assay and immunophenotypic analysis. In this study, we demonstrated the presence of cells with endothelial phenotype at the beginning of hematopoietic differentiation by formation of embryoid bodies, possibly showing that hematopoietic progenitor cells originate from a hemogenic endothelium. We generated cells with characteristics of hematopoietic stem/progenitor cells, of CD34+CD45+ and CD45+CD43+ phenotypes, erythroid progenitors (CD36+, CD71+ and CD235a+), as well as the formation of hematopoietic colonies in culture in semi-solid medium. The iPSC line PBscd08 demonstrated greater potential for differentiation into hematopoietic and erythroid cells than the other cell lines evaluated. The iPSC line PBscd01, also generated from peripheral blood mononuclear cells (PBMC) from patients with sickle cell anemia, did not demonstrate the same potential for hematopoietic differentiation, generating only CD34+ cells and a low percentage of CD45+ and CD43+ cells. The iPSC line PB12, generated from healthy individual PBMC, promoted the generation of CD34+, CD45+ and CD43+ cell populations, but not double-positives, and the generation of cells with myeloid cell morphology after maturation. The iPSC cell lines demonstrated variability in the potential for hematopoietic differentiation. This shows the need for future studies for a more detailed investigation.

As células-tronco de pluripotência induzida (iPSC) são células geradas a partir da reprogramação de células somáticas e têm potencial para diferenciação em todos os tipos celulares do organismo adulto. A indução da diferenciação de iPSC pacienteespecífico em células hematopoéticas é uma forma de estudo da hematopoese em modelos de doenças, como a anemia falciforme, e também essencial para o desenvolvimento de terapias. O presente estudo propôs a geração de célulastronco/progenitoras hematopoéticas e progenitores eritroides in vitro a partir de iPSC derivadas de pacientes com anemia falciforme através da formação de corpos embrioides. Ao longo da diferenciação, os desenvolvimentos hematopoético e eritroide foram monitorados através de ensaios de formação de colônia e imunofenotipagem por citometria de fluxo. Neste estudo, demonstramos a presença de células com fenótipo de células endoteliais no início da diferenciação hematopoética por formação de corpos embrioides, possivelmente indicando que as células progenitoras hematopoéticas são provenientes de um endotélio hemogênico. Também verificamos a presença de células endoteliais sem potencial de endotélio hemogênico. Geramos células com características de células-tronco/progenitoras hematopoéticas, de fenótipos CD34+CD45+ e CD45+CD43+, progenitores eritroides (CD36+, CD71+ e CD235a+), bem como a formação de colônias hematopoéticas em cultura em meio semi-sólido. A linhagem de iPSC PBscd08 demonstrou maior potencial para diferenciação em células hematopoéticas e eritroide que as demais linhagens celulares avaliadas. A linhagem PBscd01, também gerada a partir de células mononucleares do sangue periférico (PBMC) de paciente com anemia falciforme, não demonstrou o mesmo potencial para a diferenciação hematopoética, gerando apenas células CD34+ e baixa porcentagem de células CD45+ e CD43+. A linhagem de iPSC PB12, gerada a partir de PBMC de indivíduo saudável, promoveu a geração de populações de células CD34+, CD45+ e CD43+, mas não duplo-positivas, e a geração de células com morfologia de células mieloides após a maturação. As linhagens celulares de iPSC demonstraram variabilidade quanto ao potencial de diferenciação hematopoética. Isto monstra a necessidade de estudos futuros para uma investigação mais detalhada. / Induced pluripotent stem cells (iPSC) are cells generated by reprogramming somatic cells, they have the potential for differentiation into all types of cells in the adult organism. The differentiation of patient-specific iPSC into hematopoietic cells is a way of studying hematopoiesis in disease models, such as sickle cell anemia, and is also essential for the development of therapies. The present study proposed the generation of hematopoietic stem/progenitor cells and erythroid progenitors from iPSC derived from patients with sickle cell anemia. Throughout the differentiation, hematopoietic and erythroid developments were monitored by colony forming cell assay and immunophenotypic analysis. In this study, we demonstrated the presence of cells with endothelial phenotype at the beginning of hematopoietic differentiation by formation of embryoid bodies, possibly showing that hematopoietic progenitor cells originate from a hemogenic endothelium. We generated cells with characteristics of hematopoietic stem/progenitor cells, of CD34+CD45+ and CD45+CD43+ phenotypes, erythroid progenitors (CD36+, CD71+ and CD235a+), as well as the formation of hematopoietic colonies in culture in semi-solid medium. The iPSC line PBscd08 demonstrated greater potential for differentiation into hematopoietic and erythroid cells than the other cell lines evaluated. The iPSC line PBscd01, also generated from peripheral blood mononuclear cells (PBMC) from patients with sickle cell anemia, did not demonstrate the same potential for hematopoietic differentiation, generating only CD34+ cells and a low percentage of CD45+ and CD43+ cells. The iPSC line PB12, generated from healthy individual PBMC, promoted the generation of CD34+, CD45+ and CD43+ cell populations, but not double-positives, and the generation of cells with myeloid cell morphology after maturation. The iPSC cell lines demonstrated variability in the potential for hematopoietic differentiation. This shows the need for future studies for a more detailed investigation.

Resumo: Crianças com anemia falciforme são submetidas à terapia antibiótica profilática prolongada com penicilina. Pouco se sabe a respeito dos efeitos desta terapia sobre a microbiota bucal. O objetivo do estudo foi avaliar a microbiota cariogênica, fluxo e capacidade tampão salivar de pacientes pediátricos com anemia falciforme, determinando o risco de cárie. Além disso, avaliar a microbiota fúngica nestes pacientes em relação ao grupo controle. Foi coletada saliva estimulada de 25 crianças (4 a 11 anos) com anemia falciforme (genótipo SS), de ambos os gêneros. Um grupo controle pareado quanto à idade e gênero foi incluído. Foi realizado exame clínico para verificação do índice ceo-d/CPO-D; o fluxo salivar e a capacidade tampão salivar foram avaliados. Alíquotas de saliva e diluições foram semeadas em meios seletivos para estreptococos do grupo mutans, lactobacilos e leveduras. Após a incubação, o número de UFC/mL de saliva foi calculado. Amostras de leveduras foram isoladas, e identificadas pelo sistema API 20C AUX, além de PCR específico para C. dubliniensis. Os dados obtidos por meio do questionário, dados salivares e microbiológicos foram analisados pelo software Cariograma. Os resultados foram comparados pelo teste t de Student, teste Z e Mann-Whitney. Não foi observada diferença estatisticamente significativa para o fluxo (p = 0,097) e capacidade tampão salivar (p = 0,103) entre os grupos de estudo. A contagem de leveduras foi significativamente mais elevada no grupo de estudo (p = 0,017). As contagens de estreptococos do grupo mutans e lactobacilos não diferiram significativamente entre o grupo teste e o grupo controle (p = 0,741 e p = 0,423, respectivamente). Considerando estes resultados em conjunto com os demais parâmetros avaliados, concluiu-se que o risco de cárie entre os grupos não diferiu (p = 0,762). No grupo de estudo foram identificados:... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Children with sickle cell anemia are under long term prophylactic antibiotic treatment with penicillin. Little is known about the effects of this therapy on oral microbiota. The aim of the study was to evaluate the cariogenic microbiota, salivary flow rate and buffering capacity of pediatric patients with sickle cell anemia, to delineate a profile of caries risk. Also, the study aimed to evaluate the fungal microbiota in these patients in relation to control individuals. Sample of stimulated saliva from 25 children (aged 4 - 11) with sickle cell anemia (genotype SS) and both genders was collected. A matched control group was included. Intra-oral examination to determine dmft/DMFT index; salivary flow rate and buffering capacity evaluation were performed. Aliquots of saliva and its dilutions were plated onto selective media to mutans streptococci, lactobacilli and yeasts. After the incubation (37ºC, 48h, 5% CO2 to mutans streptococci), the value of cfu/ml of saliva was calculated. Strains of yeasts were isolated, and identified by API 20C AUX and C. dubliniensis by PCR. Data obtained by a questionnaire, salivary and microbiological data were analyzed by Cariogram program. The results were compared by Student's t test, Z test and Mann-Whitney. No significant difference were observed for the salivary flow (p = 0.097) and salivary buffering capacity (p = 0.103) of the studied groups. Counts of yeasts were significantly higher in the study group (p = 0.017). Counts of mutans streptococci and lactobacilli were not different between test and control groups (p = 0.741 e p = 0.423, respectively). Considering these results and the other parameters studied, it could be concluded that the caries risk between the groups was not different (p = 0. 762). In the study groups the following Candida species were identified: C. albicans, C. dubliniensis, C. famata, C. rugosa, C. sphaerica... (Complete abstract click electronic access below) / Orientador: Cristiane Yumi Koga Ito / Coorientador: Josefina Aparecida Pellegrini Braga / Banca: Maria Stella Figueiredo / Banca: Antonio Olavo Cardoso Jorge / Mestre

Sickle cell disease (SCD) is a genetic disorder that affects millions of people worldwide. According to the Centers for Disease Control and Prevention, over 100,000 Americans have SCD, and more than 2 million Americans have a sickle cell trait (SCT). People with SCD are more likely than others to suffer premature mortality. Genetic screening is an important step in improving quality of life and increasing longevity for those with SCD. Early detection may lead to effective management of the disease and reduction of complicating factors. The purpose of this quasi-experimental study was to determine whether health education about SCD would impact college students' knowledge, attitudes, perceived risk, and intention to seek genetic screening and counseling in relation to the disease. The theoretical foundation for this study was the health belief model (HBM). This study involved 80 college students selected from a North Texas college. These students completed pre and post versions of an SCD questionnaire. Independent samples t tests were used to determine if there were significant differences in pre- and posttest scores of participants in both groups, and a MANOVA was used to determine differences among the scores of participants in the experimental group when grouped by age, gender, race, religiosity, and socioeconomic status. The results of this study showed that SCD health education improved the knowledge of and attitudes towards participants. Future research could explore barriers to seeking SCD screening and genetic counseling. Results of this study may further social change by encouraging the development of college-based health education efforts to increase awareness about SCD.

Sickle cell disease (SCD) is a genetic disorder that affects millions of people worldwide. According to the Centers for Disease Control and Prevention, over 100,000 Americans have SCD, and more than 2 million Americans have a sickle cell trait (SCT). People with SCD are more likely than others to suffer premature mortality. Genetic screening is an important step in improving quality of life and increasing longevity for those with SCD. Early detection may lead to effective management of the disease and reduction of complicating factors. The purpose of this quasi-experimental study was to determine whether health education about SCD would impact college students' knowledge, attitudes, perceived risk, and intention to seek genetic screening and counseling in relation to the disease. The theoretical foundation for this study was the health belief model (HBM). This study involved 80 college students selected from a North Texas college. These students completed pre and post versions of an SCD questionnaire. Independent samples t tests were used to determine if there were significant differences in pre- and posttest scores of participants in both groups, and a MANOVA was used to determine differences among the scores of participants in the experimental group when grouped by age, gender, race, religiosity, and socioeconomic status. The results of this study showed that SCD health education improved the knowledge of and attitudes towards participants. Future research could explore barriers to seeking SCD screening and genetic counseling. Results of this study may further social change by encouraging the development of college-based health education efforts to increase awareness about SCD.