Introdução: a doença falciforme (DF) é uma condição crônica e de caráter hereditário que, devido a sua importância clínica e epidemiológica, constitui-se em um grave problema de saúde pública. As famílias de crianças com esta condição alteram suas rotinas e manejam os cuidados buscando adaptarem-se às frequentes crises e hospitalizações. Objetivos: este estudo visou conhecer a experiência de manejo familiar da criança com doença falciforme e, especificamente, procurou identificar como as famílias definem a situação, buscando compreender os comportamentos de manejo adquiridos na experiência do cuidado, além de conhecer as consequências percebidas pela família e geradas pela doença falciforme da criança. Método: trata-se de uma pesquisa qualitativa que utilizou o Family Management Style Framework como referencial teórico e, como método, o estudo de caso sendo os dados analisados segundo o modelo híbrido de análise temática. A amostra foi composta por oito famílias de crianças com DF que fazem os acompanhamentos em um Hemonúcleo da Fundação Centro de Hematologia e Hemoterapia de Minas Gerais, as quais participaram de três entrevistas em profundidade, avaliadas por meio da composição de hemograma, ecomapa, linha do tempo da doença e análise de documentos, como exames, receituários e sumários de alta hospitalar. Resultados: as famílias definiram a situação da doença falciforme como um evento Assustador e de difícil Entendimento; a identidade das crianças oscilou entres as características de Vulnerável a Normal entendido como qualquer outra criança. Os comportamentos de manejo incidem sobre a responsabilidade que as famílias sentem em manterem a criança por perto, sendo vigilantes no controle da doença e buscando a manutenção da vida e do bem-estar desta criança. Assim, as famílias procuram adaptar-se às novas situações impostas pela doença. As consequências percebidas refletem que o foco destas famílias está na criança doente e no estímulo para que as crianças gerenciem os seus próprios cuidados preparando-as para a fase adulta. As expectativas familiares sobre o futuro estão na possibilidade de cura e de uma vida dentro da normalidade, embora relatem o medo da morte diante do curso incerto da doença. Considerações finais: a compreensão do manejo familiar das crianças com doença falciforme subsidiou propostas de intervenções, para estas famílias, com o intuito de orientá-las e apoiá-las na experiência do manejo; além de encorajar os profissionais de saúde que atuam com estas famílias a utilizarem este modelo de avaliação teórica para a execução de suas intervenções em todos os níveis de assistência à saúde. / Introduction: Sickle cell disease (SCD) is a chronic and hereditary condition that, due to its clinical and epidemiological importance, is a serious public health problem. The families of children with this condition alter their routines and manage the care seeking to adapt to frequent crises and hospitalizations. Objectives: This study aimed to know the experience of family management of the child with sickle cell disease and, specifically, sought to identify how families define the seeking to understand the management behaviors acquired in the care experience, as well as to understand the consequences perceived by the family and generated by the sickle cell disease of the child. Method: this is a qualitative research that used the Family Management Style Framework as a theoretical reference and, as a method, the case study - being the data analyzed according to the hybrid model of thematic analysis. The sample consisted of eight families of children with SCD who follow the follow-up in a Hemodynamic and Haemotherapy Center Foundation Hemodynamic of Minas Gerais, who participated in three in-depth interviews, evaluated through the composition of genogram, ecomapa, line time of disease and document analysis, such as exams, prescriptions and hospital discharge summaries. Results: Families defined sickle cell disease as a \"scary\" event and difficult to understand. Children\'s identities ranged from \"Vulnerable\" to \"Normal\" - understood as \"any other child\". Management behaviors focus on the responsibility that families feel in keeping the child close, being vigilant in controlling the disease and seeking to maintain the life and well-being of this child. Thus, families seek to adapt to the new situations imposed by the disease. The perceived consequences reflect that the focus of these families is on the sick child and the encouragement for children to manage their own care - preparing them for adulthood. Family expectations about the future lie in the possibility of healing and living within normality, even though they report the fear of death in the face of the uncertain course of illness. Final considerations: understanding the family management of children with sickle-cell disease subsidized intervention proposals for these families, with the aim of guiding them and supporting them in the management experience; in addition to encouraging health professionals working with these families to use this theoretical evaluation model for the execution of their interventions at all levels of health care.

Orientador: Fernando Ferreira Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T14:17:07Z (GMT). No. of bitstreams: 1 Bezerra_MarcosAndreCavalcanti_D.pdf: 919225 bytes, checksum: 5524005c5d425fe7e16e9c36cfd7275b (MD5) Previous issue date: 2009 / Resumo: O estado inflamatório crônico que ocorre na doença falciforme (DF) é decorrente de diversos fatores que se interligam e se retroalimentam, formando um ciclo inflamatório permanente. Estudos prévios sobre as propriedades adesivas e funcionais das células são restritos à forma homozigota do gene da HbS (SS). No entanto, trabalhos que avaliem essas características celulares, que possam contribuir para o esclarecimento da heterogeneidade clínica em outros grupos de DF e talassemia intermediária (TI), são escassos na literatura. O objetivo desse trabalho foi avaliar a capacidade adesiva de células vermelhas, neutrófilos e plaquetas, quimiotaxia dos neutrófilos, os níveis plasmáticos das citocinas inflamatórias e o stress oxidativo na DF e ß-TI. Dessa maneira foram selecionados pacientes com DF: SS (n=20), SC (n=20), 3 grupos com S/ß talassemia - S/ß-IVS-I-6 (T->C) (n=17), S/ß-IVS-I-5 (G->C) (n=16), S/ß-Códon39 (C??T) (n=12) - e TI homozigotos para a mutação IVS-I-6 (T->C) (n=20), acompanhados na Fundação HEMOPE. As técnicas utilizadas no desenvolvimento desse estudo foram: ensaio de quimiotaxia (ChemoTx) para avaliação da capacidade migratória dos neutrófilos, adesão estática para determinação da adesão basal das células, citometria de fluxo para avaliar a produção de ROS e a expressão de moléculas de adesão, e ELISA para determinar a atividade da superóxido dismutase (SOD) e a dosagem das citocinas. Para avaliação de nossos resultados, todos os grupos de pacientes foram comparados ao grupo controle AA: a adesão de neutrófilos e plaquetas mostrou-se significativamente aumentada em todos dos grupos de DF; somente os grupos SS e SC apresentaram capacidade quimiotática significativamente aumentada, assim como a adesão de células vermelhas e a expressão das moléculas de adesão CD36 e CD49d. Os níveis plasmáticos das citocinas IL1-ß, IL-6, IL-8 e TNF-a mostraram-se significativamente aumentados no grupo SS, e nos demais grupos de DF apresentaram uma distribuição heterogênea. Observamos um aumento significativo na produção de ROS em células vermelhas, mononucleares e neutrófilos de todos os grupos de DF, exceto para os grupos S/ß nas células vermelhas. Além disso, a atividade plasmática da SOD mostrou-se reduzida nos grupos SS, SC e S/ß-Cd39. A adesão dos neutrófilos, células vermelhas e plaquetas foi significativamente maior nos pacientes com TI, assim como a expressão das moléculas CD36 e CD49d nas células vermelhas e a capacidade quimiotática dos neutrófilos. Nesses pacientes, a produção de ROS e os níveis plasmáticos das citocinas foram significativamente aumentados, enquanto que a atividade enzimática da SOD foi significativamente reduzida. Apesar da doença SC possuir uma clínica mais branda, nossos dados sugerem que neutrófilos, glóbulos vermelhos e plaquetas desses pacientes possuem características adesivas e quimiotáticas semelhantes às encontradas nas células de pacientes com AF. Além disso, nossos resultados sugerem que quanto maiores os níveis de HbA na S/ß talassemia, menor a adesão de neutrófilos, células vermelhas e plaquetas, podendo explicar as diferenças clínicas encontradas nesses pacientes em função do genótipo. É possível que o aumento da aderência, da capacidade quimiotática, da produção de ROS, das citocinas e diminuição do mecanismo antioxidante, observados neste estudo, contribuam nas complicações clínicas encontradas na ß-TI, tais como hipertensão pulmonar e úlceras de perna. Estudos adicionais podem contribuir para o entendimento das diferenças na apresentação clínica desses pacientes. / Abstract: The chronic inflammatory state that occurs in sickle cell disease (SCD) is due to several factors that are interlinked and feeds back to a permanent inflammatory cycle. Previous studies about the adhesive properties and functional cells are restricted to the homozygous form of the HbS gene (SS). However, studies that assess the cellular characteristics that may contribute to the clarification of clinical heterogeneity in other groups of SCD and thalassemia intermedia (TI), are scarce in the literature. The aim of this study was to evaluate the adhesive properties of red blood cells (RBC), platelets and neutrophils (NS), NS chemotaxis, inflammatory cytokine plasma levels and oxidative stress in SCD and ß-TI patients. Thus, we selected patients with different SCD genotypes: SS (n=20), SC (n=20), three groups of HbS/ß thalassemia - HbS/ß39 (C->T) (n=12), HbS/IVSI- 5 (G->C) (n=16), and HbS/IVS-I-6 (T->C) (n=17) - and patients with homozygous thalassemia intermedia IVS-I-6 (T->C) - followed regularly at the Fundação HEMOPE - Brazil. The techniques used in the development of this study were: chemotaxis assay (ChemoTx) to evaluate the migratory ability of neutrophils, basal adhesion was compared using static adhesion assays, flow cytometry to assess the production of ROS and expression of adhesion molecules, and ELISA to determine the superoxide dismutase (SOD) activity and cytokine plasma levels. For evaluation of our results, all groups of patients were compared with the AA control group: the neutrophil and platelet adhesions were significantly increased in all groups of SCD, only the SS and SC groups showed significant increase in the chemotactic ability, as well as the RBC adhesion and the expression of adhesion molecules CD36 and CD49d. All the SCD groups investigated showed an increase in IL-6 plasma levels. IL1-ß levels were significantly higher in the S/ß-IVS-I-5 (G??C), S/ß-Cd39 and SS groups. Plasma levels of IL-8 were increased only in the SS and SC groups, however TNF-a levels were significantly higher in SS and the three groups with HbS-ß thalassemia. NS and mononuclear cell ROS production was significantly increased in all SCD groups, however red blood ROS production was higher only in the SS and SC groups. Moreover, the SOD plasma activity was shown to be reduced in groups SS, SC and S/ß-Cd39. The NS, RBC and platelets adhesion was significantly higher in TI patients, as well as the expression of molecules CD36 and CD49d in RBC and chemotactic ability of NS. In these patients, the ROS production and cytokines plasma levels were significantly increased, while SOD plasma activity was significantly reduced. Although SC disease has a milder clinical manifestations, our data suggest that NS, RBC and platelets of these patients have chemotactic and adhesive characteristics similar to those found in cells of patients with SS. Moreover, our results suggest that the higher levels of HbA in S/ß thalassemia reduce the NS, RBC and platelets adhesion and may explain the clinical differences found in these patients, according to genotype. It is possible that the increase in the cell adherence, chemotactic capacity, ROS production, of cytokines levels and the reduction in antioxidant mechanism, observed in this study, contribute to several clinical complications of ß-TI, such as pulmonary hypertension and leg ulcers. Further studies may contribute to our understanding of the differences in the clinical presentation of these patients. / Doutorado / Medicina Experimental / Doutor em Fisiopatologia Medica

The purpose of this study is to survey self-reported health symptoms and knowledge of Sickle Cell Trait in young adults with an African heritage. The aim is to expand a comprehensive assessment system to measure factors associated with carrying the Sickle Cell Trait. Historically being a Sickle Cell Trait carrier was thought to be asymptomatic. However, current research has suggested this may not be true. While young adults may have greater knowledge of Sickle Cell Disease, little is known about their awareness of Sickle Cell Trait. Furthermore, no research on these topics have been conducted in young adults with African heritage (Latino/Hispanic, Caribbean, Multi-Racial, etc.). Measures of Sickle Cell Trait Carrier Awareness, Sickle Cell Trait Knowledge, and Physical Health Symptoms are presented from 54 young adults with African Heritage. The Hispanic and Multi-Racial participants reported lower awareness of their Sickle Cell Trait Carrier status compared to the African American participants. Hispanic and Multi-Racial participants reported lower Sickle Cell Trait Knowledge compared to the African American participants. All subjects demonstrated lower levels of Sickle Cell Trait Knowledge than would be expected given the potential health consequences.

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.

Sickle cell disease is a genetic disorder that affects 100,000 Americans and millions more worldwide. Although the sickle mutation affects one protein, which is only expressed in a single cell type, it has profound detrimental effects on nearly every organ system in the body. Young children with sickle cell disease have an 11\% chance of suffering a major stroke event by the age of 16, and a 35\% chance of developing ÒsilentÓ strokes that often result in significant learning and mental disabilities. Clinical investigations suggest that stroke development in people with sickle cell disease results from luminal narrowing of the carotid and cerebral arteries due to excess matrix deposition and fragmentation of the elastic lamina; however, the underlying cellular mechanisms that initiate arterial remodeling in sickle cell disease remain relatively unknown. Cathepsins K and V are members of the cysteine family of proteases and represent two of the most potent elastases yet identified in humans. Furthermore, the role of Cathepsins has been well established in other cardiovascular remodeling diseases, such as atherosclerosis. Due to the compelling histological similarities between vasculopathy in sickle cell disease and atherosclerosis, we tested the hypothesis that the unique inflammatory milieu, in conjunction with the biomechanical vascular environment of sickle cell disease upregulates cathepsin K and V activity in large artery endothelial cells, ultimately leading to arterial remodeling and stroke. Currently, there are few therapeutic options for the prevention of stroke in sickle cell disease; those that do exist carry significant health risks and side effects. Together, this body of work has generated a more mechanistic understanding of how the sickle milieu stimulates the endothelium to initiate arterial remodeling, which has enabled us to identify important pathways (JNK, NF$\kappa$B) downstream of inflammatory and biomechanical stimuli and validate new therapeutic targets within the JNK pathway to establish preclinical proof of efficacy for the prevention of arterial remodeling in sickle cell disease.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The high sickle cell gene frequency has been hypothesised to be related to the protective advantage against malaria disease among heterozygous individuals. In this thesis, we study the interaction between the dynamics of malaria and sickle cell gene. The main aim is to investigate the impact of malaria treatment on the frequency of sickle cell gene. For this, we develop a mathematical model that describes the interactions between malaria and sickle cell gene under malaria treatment. The model includes both homozygous for the normal gene (AA) and heterozygous for sickle cell gene (AS) and assumes that AS individuals are not treated since they do not show clinical symptoms. We first analyse the model without malaria treatment, using singular perturbation techniques, basing on the fact that epidemiological and demographical dynamics occur on two different time scales (fast and slow dynamics). Our analysis on the fast time scale shows that high sickle cell gene frequency leads to high endemic levels for longer duration of parasitemia among heterozygous individuals. However, if the duration of parasitemia is reduced then high sickle cell gene frequency is associated with low endemic levels. We also note that on the slow time scale, the invasion ability of sickle cell gene is dependent on the malaria epidemiological parameters. The invasion coefficient given as the difference in the weighted death rates of AA and AS individuals is used as a measure to determine the establishment of sickle cell gene in the population. Results show that, the gene may establish itself if the weighted death rate of AA individuals is greater than that of AS individuals otherwise it fails. We note that, high mortality of AA individuals leads to establishment of sickle cell gene in the population. Then we analysed the model with treatment, our results indicate that the frequency of sickle cell gene decreases with an increase in the recovery rate of AA individuals. We thus conclude that eradication of malaria disease will lead to a reduction in sickle cell gene frequency. / AFRIKAANSE OPSOMMING: Daar word veronderstel dat die hoë sekelsel geenfrekwensie onder heterosigotiese individue verwant is aan die beskermende voordeel teen malaria siekte. In hierdie verhandeling ondersoek ons die wisselwerking tussen die dinamika van malaria en die sekelsel geen. Die hoofdoel is om die invloed van malaria behandeling op die frekwensie van die sekelsel geen te ondersoek. Hiervoor het ons ‘n wiskundige model ontwikkel, wat die wisselwerking tussen die dinamika van malaria en die sekelsel geen met malaria behandeling, beskryf. Die model sluit beide homosigotiese vir die normale geen (AA) en heterosigotiese vir die sekelsel geen (AS) in, en neem aan dat AS individue nie behandel is nie omdat hulle nie die eerste kliniese simptome getoon het nie. Ons ontleed eers die model sonder malaria behandeling, deur gebruik te maak van enkelvoudige pertubasie tegnieke, wat gegrond is op die feit dat epidemiologiese en demografiese dinamika plaasvind op twee verskillende tydskale (vinnige en stadige dinamika). Ons ontleding op die vinnige tydskaal dui dat hoë sekelsel geenfrekwensie onder heterosigotiese individue lei tot hoë endemiese vlakke vir ‘n langer duur van parasitemie. Nietemin, as die duur van parasitemie afneem, dan word hoë sekelsel geenfrekwensie verbind met lae endemiese vlakke. Ons neem ook waar dat op die stadige skaal die indringingsvermoë van die sekelsel afhanklik is van malaria se epidemiologiese parameters. Die indringingskoëffisiënt wat bereken word as die verskil van die geweegde sterftekoerse van AA en AS individue, word gebruik as ‘n maatstaf om die vestiging van die sekelsel geen in die bevolking te bepaal. Resultate toon dat die geen homself kan vestig as die geweegde sterftekoers van AA individue groter is as di e van die AS individue, andersins misluk dit. Ons let op dat hoë mortaliteit van AA individue lei tot die vestiging van die sekelsel geen in die bevolking. Daarna het ons die model wat behandeling insluit ge-analiseer en ons resultate toon dat die frekwensie van die sekelsel geen afneem met ‘n toename in die herstelkoers van AA individue. Ons kom dus tot die gevolgtrekking dat die uitwissing van malaria siekte sal lei tot die afname in sekelsel geenfrekwensie.

No description available.

<p>Malaria, caused by the apicomplexan parasite Plasmodium, is a disease which affects up to 500 million people each year. Historically, malaria infection has been combated both through the control of its vector, the Anopheles mosquito, and use of a variety of drugs, such as quinine (1800s) and chloroquine (1900s). However, with the evolution of resistance to the majority of available anti-malarial drugs, current approaches have settled upon combinatorial therapies. The most effective of these currently are ACTs (Artemisinin Combination Therapies - Artemisinin derivatives combined with a number of other drugs). However reports of Artemisinin resistance are continuing to emerge, suggesting that new approaches and increased understanding of the Plasmodium parasite is required.</p><p> Beginning with the complete sequencing of Plasmodium falciparum genome and continuing with comprehensive profiling of both the parasite's proteome and transcriptome, various genomic approaches applied in the study of malaria have led to significant new insights into the underlying biology of this parasite. While these new findings have greatly increased our understanding of genetic regulation within the malaria parasite, they largely have not yet translated into new therapeutic approaches. For this reason, considerable attention has been paid to the study of human genetic disorders which convey resistance to malaria, in the hopes that elucidating the mechanisms behind these resistances might lead to increased understanding of the parasite's biology and thus novel therapeutic approaches.</p><p> Sickle cell (HbS) erythrocytes are well known to resist malaria infection. However, the molecular basis of this resistance, long been recognized as multifactorial, contains elements which remain poorly understood. Here we show that the dysregulated erythrocytic microRNA composition, present in both HbAS and HbSS erythrocytes, is a significant determinant of resistance against the malaria parasite Plasmodium falciparum. During the intraerythrocytic lifecycle of P. falciparum, a subset of erythrocyte microRNAs translocate into the parasite. Two microRNAs, miR-451 and let-7i, were highly enriched in HbAS and HbSS erythrocytes and these miRNAs, along with miR-223, negatively regulated parasite growth. Surprisingly, we found that miR-451 and let-7i integrated into essential parasite mRNAs and, via impaired ribosomal loading, resulted in translational inhibition of the target mRNA. Hence, sickle cell erythrocytes exhibit cell-intrinsic resistance to malaria in part through an atypical microRNA activity which may present a novel host defense strategy against complex eukaryotic pathogens. In addition, the formation of these chimeric transcripts even in normal host erythrocytes illustrates a unique parasitic post-transcriptional adaptation to the host-cell environment.</p> / Dissertation

The enormous mortality burden exerted by P. falciparum malaria has evolutionarily selected for red blood cell (RBC) polymorphisms which confer protection against the severe manifestations of this disease. Although the epidemiological protection by these polymorphisms has been well-established for the past half-century, the mechanisms underlying this protection are still being uncovered. Recent studies implicate impaired cytoadherence to microvascular endothelial cells (MVECs) due to reduced surface levels and altered display of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) as a mechanism of protection against severe malaria by sickle hemoglobin (Hb) S and HbC. Consequently, in this thesis, I have described three separate, but related investigations into whether hemoglobins S and C influence a parasite’s cytoadherence binding phenotype (Chapter 3), the PfEMP1 variants that parasites express in vivo (Chapter 4), and the IgG recognition of PfEMP1 domains in Malian children (Chapter 5). We found that parasites from HbAS children show statistically insignificant increased binding to MVECs and that parasites did not express a restricted subset of var genes in HbAS and HbAC children. Compared to HbAA and HbAC children, HbAS children demonstrated a slower rate of acquisition of IgG responses to a repertoire of PfEMP1 domains. These findings suggest that, although hemoglobin type influences the binding phenotype of P. falciparum isolates and the acquisition of PfEMP1-specific IgG responses, other factors more likely determine the expressed var gene repertoire within parasites than hemoglobin type.

Sickle cell disease (SCD) is one of the most common genetic diseases worldwide. HbS polymerisation causes altered red blood cell (RBC) rheology and fragility, increase in blood viscosity with blockage of small blood vessels, and RBC membrane permeability changes. Excessive levels of cell-free Hb, high autoxidation of Hb, contribute to the production of reactive oxygen species (ROS) in SCD patients. In this work, oxidants showed direct and indirect effects on the main cation permeability pathways involved in dehydration of HbS/S RBCs - Psickle, the Gardos channel and the KCl cotransporter (KCC) - and thus on RBC volume causing polymersation. Psickle and Gardos channel activities showed significant correlation, consistent with the hypothesis that Ca2+ entry via Psickle causes activation of the Ca2+-dependent K+ channel. Treatment of SCD remains inadequate relying on the blood transfusion and supportive therapy depending on the organ affected. In the present study antioxidants and aromatic aldehydes showed some promising results towards future alternative treatments for SCD. Antioxidants showed inhibitory effects on the cation permeability pathways leading to inhibition of polymerisation and haemolysis and thus maintained RBC volume. Aromatic aldehydes interact with HbS and are usually given to increase oxygen affinity, thereby reducing its tendency to polymerise. GBT1118 had a marked inhibitory effect on all three cation permeability pathways. It reduced sickling, Psickle and Gardos activity. It inhibited KCC by affecting the regulatory protein phosphorylation cascade. It maintained RBC hydration, and stabilised RBCs. Historically Oman was the principal trading port of the Persian Gulf region, resulting in the complex mix of social and ethnic backgrounds. In 1989 a second mutation in the β chain of Hb, at position β121 was found in an Omani patient in addition to the usual HbS mutation at the β6 position, and termed HbS-Oman. At low percentage of HbS-Oman patients show severe SCD symptoms. Despite RBCs containing at most 25% HbS-Oman, there was high sickling percentage and K+ permeability showed many features similar to those seen in homozygous HbS/S patients. The presence of α thalassaemia was protective and represents an obvious potential prognostic marker for this rare SCD genotype. Overall, the present work contributes to elucidation of the pathogenesis of SCD, suggests approaches to the development of novel therapies and increases our understanding of a rare SCD genotype, HbS-Oman.