Introduction: Sickle cell disease (SCD) affects predominately African Americans and is one of the most prevalent diseases in the United States (Schecter, 1999). Research has not sufficiently examined whether pain associated with SCD impacts quality of life or whether coping impacts this relation. The purpose of this study was to examine the relation between pain and quality of life in children with SCD and to determine whether coping moderates the relation. A secondary aim was to examine associations between age and pain, quality of life, and coping. A final exploratory aim was to examine the relation between racial identity and study variables. Method: 104 children (M = 12.93 years, SD = 3.17 years) with SCD and their parents participated during a regularly scheduled SCD-related medical visit. Parents completed a demographic form. Children completed the Pediatric Pain Questionnaire (PPQ), the Pain Coping Questionnaire (PCQ), the Pediatric Quality of Life Inventory (PedsQL), Sickle Cell Disease Quality of Life (SCD-QoL), and the Multidimensional Inventory of Black Identity (MIBI). Results: After controlling for site and gender, regression analyses revealed that pain (ƒÒ = -0.37) and emotion-focused avoidance coping (ƒÒ = -0.39) were significant predictors of overall generic quality of life (PedsQL Total Score), total R2 = 0.44, F (5, 93) = 13.88, p < 0.001. There was no significant pain x coping interactions found for overall generic quality of life. Child age was not associated with study variables. Exploratory analyses revealed the MIBI Centrality Scale was associated with PCQ Approach Coping, r (80) = -0.24, p < 0.05, and the MIBI Regard Scale was correlated with PCQ Problem-Focused Avoidance Coping, r (84) = 0.30, p < 0.01. Discussion: This study found that pain and emotion-focused avoidance coping were inversely associated with quality of life in children with SCD. Coping was not found to moderate the relation between pain and overall quality of life. The associations between racial identity and coping demonstrate the importance of further examining cultural factors in children with SCD. In addition, there continues to be a need for future research to focus on the psychosocial functioning of children with SCD.

Sickle Cell Disease (SCD) is a genetic disorder that affects approximately 1 out of every 600 African-American newborns (NHLBI, 2006). SCD and its associated symptoms can have widespread impact on both the psychological functioning of the individual diagnosed with the illness and their families. The purpose of this study was to apply the illness intrusiveness framework to better understand the relations among vaso-occlusive pain crises (VOC), child age, pediatric health related quality of life (QOL), and parental psychosocial adjustment. Participants included 103 parent-child dyads. Parents completed a background form, the Brief Symptom Inventory-18, and the Illness Intrusiveness Rating Scale. Children completed the Pediatric Quality of Life Inventory. Results revealed that experiencing a greater frequency of VOC’s was related to decrements in QOL across domains. However, this relation was not mediated by parental perceived illness intrusiveness. Further, results revealed that the effect of frequency of vaso-occlusive pain crises in children with SCD on parental psychosocial maladjustment is mediated by parental illness intrusiveness, which is contingent upon child age.

Sickle Cell Disease (SCD) is a genetic disorder that affects approximately 1 out of every 600 African-American newborns (NHLBI, 2006). Research suggests that caregivers of children with SCD are at risk for maladjustment. The purpose of this current study was to build upon previous research regarding stress and coping of parents of children with SCD. Additionally, novel information regarding the effects of racial identity was explored. Participants included 103 caregivers (M = 41.1 years old, SD = 8.04 years) of children with SCD. Parents completed a demographic form, the Brief Symptom Inventory-18, Pediatric Inventory for Parents, Coping Health Inventory for Parents, and the Multidimensional Inventory of Black Identity. Results revealed that increases in caregiver stress associated with parenting a chronically ill child were accompanied by increases in caregiver psychosocial maladjustment. Caregiver coping did not significantly predict functioning nor moderate the stress-adjustment relation. Exploratory analysis revealed significant associations between parents’ racial identity and parenting stress.

This dissertation thesis consists of a series of chapters that are interwoven by solving interesting biological problems, employing various computational methodologies. These techniques provide meaningful physical insights to promote the scientific fields of interest. Focus of chapter 1 concerns, the importance of computational tools like docking studies in advancing structure based drug design processes. This chapter also addresses the prime concerns like scoring functions, sampling algorithms and flexible docking studies that hamper the docking successes. Information about the different kinds of flexible dockings in terms of accuracy, time limitations and success studies are presented. Later the importance of Induced fit docking studies was explained in comparison to traditional MD simulations to predict the absolute binding modes. Chapter 2 and 3 focuses on understanding, how sickle cell disease progresses through the production of sickled hemoglobin and its effects on sickle cell patients. And how, hydroxyurea, the only FDA approved treatment of sickle cell disease acts to subside sickle cell effects. It is believed the primary mechanism of action is associated with the pharmacological elevation of nitric oxide in the blood, however, the exact details of this mechanism is still unclear. HU interacts with oxy and deoxyHb resulting in slow NO production rates. However, this did not correlate with the observed increase of NO concentrations in patients undergoing HU therapy. The discrepancy can be attributed to the interaction of HU competing with other heme based enzymes such as catalase and peroxidases. In these two chapters, we investigate the atomic level details of this process using a combination of flexible-ligand / flexible-receptor virtual screening (i.e. induced fit docking, IFD) coupled with energetic analysis that decomposes interaction energies at the atomic level. Using these tools we were able to elucidate the previously unknown substrate binding modes of a series of hydroxyurea analogs to human hemoglobin, catalase and the concomitant structural changes of the enzymes. Our results are consistent with kinetic and EPR measurements of hydroxyurea-hemoglobin reactions and a full mechanism is proposed that offers new insights into possibly improving substrate binding and/or reactivity. Finally in chapter 4, we have developed a 3D bioactive structure of O6-alkylguanine-DNA alkyltransferase (AGT), a DNA repair protein using Monte Carlo conformational search process. It is known that AGT prevents DNA damage, mutations and apoptosis arising from alkylated guanines. Various Benzyl guanine analouges of O6- methylguanine were tested for activity as potential inhibitors. The nature and position of the substitutions methyl and aminomethyl profoundly affected their activity. Molecular modeling of their interactions with alkyltransferase provided a molecular explanation for these results. The square of the correlation coefficient (R2 ) obtained between E-model scores (obtained from GLIDE XP/QPLD docking calculations) vs log(ED)values via a linear regression analysis was 0.96. The models indicate that the ortho-substitution causes a steric clash interfering with binding, whereas the meta-aminomethyl substitution allows an interaction of the amino group to generate an additional hydrogen bond with the protein. Using this model for virtually screening studies resulted in identification of seven lead compounds with novel scaffolds from National Cancer Institute Diversity Set2.

Cells often exist in heterogeneous mixtures. Density provides a property to separate several types of cells from the mixed sample in which they originate. Density-based separation methods provide a standard method to quickly separate or enrich specific populations of cells, such as lymphocytes from whole blood. This dissertation explores the use of aqueous multiphase systems (AMPS) as self-forming step-gradients in density for the separation of cells. AMPS were first discovered over a hundred years ago as aqueous two-phase systems. Density as a tool to separate cells is at least as old. Despite this long history, the work in this thesis is the first work to use AMPS to perform density-based separations on cells. This combination provides a powerful technique to separate cells and enable new testing at the point-of-care. Chapter 1 provides a short overview of aqueous multiphase systems and density-based separations of cells. Chapter 2 describes the process of taking technology, including AMPS, from a demonstration in a laboratory to a large scale evaluation in a field setting. In Chapter 3 and Appendix I, AMPS provide a means to enrich reticulocytes from whole blood as a means to grow malaria parasites. Chapter 4 and Appendix II describe the development and proof-of-prinicple of a density-based diagnostic test for sickle cell disease (SCD) using AMPS. Chapter 5 and Appendix III detail the results of a large scale field evaluation of a rapid test for SCD using AMPS in Zambia. Demonstrations of AMPS for density- and size-based separations are provided in Appendices IV and V. Appendix VI demonstrates the general usefulness of density to separate crystal polymorphs with another density-based separation method: magnetic levitation in a paramagnetic fluid. Beyond density, novel combinations of technology, such as electrochemistry and telecommunications provide opportunities for enabling global health (Appendix VII). / Engineering and Applied Sciences

Pregnancy in women with hemoglobinopathy has been associated with an increased risk of adverse pregnancy outcomes. We conducted a historical cohort study using Discharge Abstract Database for the fiscal year 1991-1992 through 2007-2008. We estimated the frequency of pregnant women with hemoglobinopathy and examined their associations with adverse pregnancy outcomes. Women with sickle cell disease are more likely to develop pre-eclampsia and preterm labor, and to undergo cesarean delivery than women with nutritional deficiency anemia, suggesting that there are other mechanisms beyond anemia that may be responsible for an increased risk of adverse pregnancy outcomes. The data suggested a synergistic effect of hemoglobinopathy and pre-eclampsia on preterm labor and cesarean delivery. Prediction models for pre-eclampsia, preterm labor and cesarean delivery were created and internally validated for women with hemoglobinopathy, with satisfactory discrimination and calibration.

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 &gt; 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).

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.

Made available in DSpace on 2015-07-22T20:50:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-24 / Objetivos. 1) Avaliar a qualidade de vida relacionada à saúde (QVRS) de crianças e adolescentes com doença falciforme assistidas em um Hemocentro de referência e 2) Mensurar a QVRS dos respectivos familiares. Métodos. Amostra de conveniência de 100 pacientes portadores de doença falciforme (64 do sexo feminino e 34 do sexo masculino), divididos em três subgrupos conforme a faixa etária: de 5 a 7 (n=18), de 8 a 12 (n=32) e de 13 a 18 (n=20) e respectivos pais. O grupo controle foi composto por 50 crianças e adolescentes aparentemente saudáveis de uma escola pública local, também divididos nos mesmos três subgrupos de idade e seus respectivos cuidadores. Foi aplicado o questionário genérico “Pediatric Quality of Life Inventory” (PedsQL) versão 4.0 às crianças e aos adolescentes de ambos os grupos; aos familiares foi aplicando o questionário genérico Medical Outcomes Study 36 – Item Short-Form Health Survey (SF-36). As respostas obtidas foram linearmente transformadas em um escore e comparadas. Resultados. Os escores dos pacientes foram significativamente mais baixos do que os escores do grupo controle (p < 0,0001) em todos os 4 aspectos estudados (capacidade física, emocional, social e atividade escolar). Com relação ao SF-36, aplicados aos pais, observamos que os escores foram mais baixos, sendo as perdas de qualidade de vida mais significativas (superiores a 50%) às relacionadas aos aspectos sócioemocionais, à saúde mental, limitação por aspectos físicos e ao estado geral de saúde. Conclusão. A doença falciforme compromete a qualidade de vida das crianças, dos adolescentes e das respectivas famílias. Os pacientes percebem restrições nos aspectos emocional, social/familiar e físico dentre outros. / Objective. 1) To evaluate the quality of life in children and adolescents with sickle cell disease attending the Blood Center reference. 2) To evaluate the quality of life of relatives of these patients. Method. We selected 100 patients (64 female, 34 male) with sickle cell disease that were divided into three subgroups with age: 5 to 7 (n = 18), 8-12 (n = 32) and 13 to 18 (n = 20), and their parents. The control group was 50 healthy children and adolescents from a public school local, also divided into the same three subgroups of age and their caregivers. The Questionnaire Pediatric Quality of life Inventory - PedsQL version 4.0 was applied in both groups - children and adolescents, in the family was applied the generic questionnaire Medical Outcomes Study 36 - Item Short-Form Health Survey (SF-36). The answers were linearly transformed into a score and compared. Results: The scores of patients were significantly lower than the scores of the control group (p <0.0001) in all four areas studied (physical, emotional, social and school activities). In the version for parents was the same in almost all respects, with the loss of quality of life more meaningful (more than 50%) were related to the socio-emotional, mental health, limited by the physical appearance and general state of health. Conclusion: Sickle cell disease affects the quality of life of children, adolescents and their families. Patients perceive restrictions in the emotional, social / family and physical and others. / TEDE / BV UNIFESP: Teses e dissertações