This thesis investigated the role of CBF assessment in the management of stroke in children with sickle cell disease (SCD). It is divided into two parts. In the first part, a systematic review of CBF assessment using different imaging modalities in SCD children was designed. The prevalence of CBF abnormalities was found to be equal to or higher than those of structural MRI and transcranial Doppler (TCD) in SCD children who have not experienced stroke. Studies reviewed suggested CBF assessment in SCD could aid in addressing brain abnormalities at the tissue level. In the second part, the arterial spin labeling (ASL) technique was used to depict CBF abnormalities in SCD children. ASL demonstrated perfusion abnormalities that seem to remain invisible in TCD measurements; CBF interhemispheric asymmetries were associated with clinically silent infarctions with no corresponding flow velocity interhemispheric asymmetries assessed with TCD.

This thesis investigated the role of CBF assessment in the management of stroke in children with sickle cell disease (SCD). It is divided into two parts. In the first part, a systematic review of CBF assessment using different imaging modalities in SCD children was designed. The prevalence of CBF abnormalities was found to be equal to or higher than those of structural MRI and transcranial Doppler (TCD) in SCD children who have not experienced stroke. Studies reviewed suggested CBF assessment in SCD could aid in addressing brain abnormalities at the tissue level. In the second part, the arterial spin labeling (ASL) technique was used to depict CBF abnormalities in SCD children. ASL demonstrated perfusion abnormalities that seem to remain invisible in TCD measurements; CBF interhemispheric asymmetries were associated with clinically silent infarctions with no corresponding flow velocity interhemispheric asymmetries assessed with TCD.

Benzylpenicillin is incubated with whole human blood. The degree of reactivity of 14C-benzylpenicillin to the components of this blood is determined via a Beckman LS-100C Liquid Scintillation Counter.The oxygen carrying capacities of penicillin treated adult normal and sickled hemoglobin are measured spectrophotometrically and compared to untreated adult normal and sickled hemoglobin.Ball State UniversityMuncie, IN 47306

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.

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.