Life Sciences Commons^™

Association Of Childhood Blood Lead Levels With Firearm Violence Perpetration And Victimization, Lindsay Rae Emer

Theses and Dissertations

Over 10,000 Americans are killed in firearm homicides each year, and an additional 40,000 are injured in nonfatal shootings. There is a significant public health need to identify risk factors that can be modified to prevent firearm violence. Environmental lead exposure is a demonstrated neurotoxicant which causes behavior changes that are known to be criminogenic. More recent research has demonstrated that homicides and nonfatal shootings differ by the circumstances that lead to the shootings (i.e. gang, domestic violence, arguments) and aggregating them could lead to biased results. Although studies have found a relationship between childhood lead exposure and criminal behaviors, …

Desert Within A City: Exploring The Relationship Between Food Security, Diet, And Body Mass Index, Jamey Ann Baietto

Theses and Dissertations

Background: Food deserts are areas of decreased access to nutritious and affordable foods. Residing within a defined food desert is thought to decrease consumption of produce, dairy, and whole grains and increase consumption of energy-dense foods as well as body mass index (BMI).

Objective: The purpose of this study was to determine the effects of the level of food security on consumption of fruits, vegetables, dairy, whole grains, high-sugar foods, high-fat foods, and BMI.

Design: A one-time, self-administered data collection packet was sent to residents of a food desert. The Dietary Screener Questionnaire was utilized to determine the average daily …

Influence Of Expectations Of Aging On Older Women’S Use Of Dietary Supplements Using The Health Promotion Theory, Barbara Emily Hekel

Theses and Dissertations

The use of vitamins, minerals and herbal supplements by older adults is increasing and changing. There are concerns about supplement quality, safety, and vitamin D overuse. Little is known about supplement use by nursing home residents and about factors that influence older women to use supplements. The current study describes the supplement use of 247 nursing home residents and 110 independent living women 65 years or older in the Midwestern United States. A secondary analysis of 247 medication administration records describes the prevalence of vitamin, mineral, and herbal supplement use of nursing home residents. Using the health promotion theory, the …

The Impact Of Stand-Biased Desks On After-School Physical Activity Behaviors In Children, Nathan Tokarek

Theses and Dissertations

The purpose of this study was to assess changes in after-school time spent performing sedentary behavior (SB), light intensity physical activity (LPA), and moderate to vigorous-intensity physical activity (MVPA) among elementary school children in response to the introduction of stand-biased desks in the classroom. Thirty-one 6th grade participants randomly assigned by their teacher to a traditional (CON) or stand-biased (INT) desk provided complete accelerometer data. After-school PA and SB were measured on four consecutive weekdays at baseline and 10-weeks. Wilcoxon Rank Sum Tests were used to detect significant differences (p<0.10) in changes in the proportion of after-school wear time performing SB and PA between groups. Results suggested no significant differences in changes in after-school time performing SB (p=0.770), LPA (p=0.740), or MVPA (p=0.470). Significant differences in the change in moderate PA (INT: -1.4%; CON: -0.2%, p=0.093) were detected. Stand-biased desks were not detrimental to children’s after-school PA and SB.

Establishing Sustainable Community Garden Interventions With Aid From Health Promotion Organizations, Rachel Joann Buenemann

Theses and Dissertations

Community garden interventions provide policy, system and environmental change at the community level to establish health behaviors, which act in contest to obesity risk factors. Limited research examines factors, which influence the sustainability of community garden interventions. Therefore, in this study, a sample of 10 Midwestern community gardens associated through funding from a health promotion organization in 2013, collected data through the interviewing and surveying of 10 garden administrators and surveying of 12 garden volunteers. The study identified garden benefits perceived by garden administrators and volunteers to include contributions to social justice, continued education, enhanced social cohesion, increased access to …

Investigation On Genetic Modifiers Of Age At Onset Of Major Depressive Disorder, Huseyin Gedik

Theses and Dissertations

Major Depressive Disorder (MDD) is a complex multifactorial disorder, which would lead to disability. Environmental and genetic factors are involved in MDD etiology. The aim of this project was to identify loci modifying age at onset (AAO) of MDD using survival models after adjusting for Childhood Sexual Abuse (CSA). To achieve this aim, a dataset was made available by the China Oxford and VCU Experimental Research on Genetic Epidemiology (CONVERGE) consortium. The study population had 5,220 controls and 5,282 cases with MDD. We performed two univariate association analyses using Cox Proportional Hazard (Cox PH) models. These two are Full Sample …

Nitrosative Stress Sensing In Porphyromonas Gingivalis: Structure And Function Of The Heme Binding Transcriptional Regulator Hcpr, Benjamin R. Belvin

Theses and Dissertations

Porphyromonas gingivalis, a Gram negative anaerobe implicated in the progression of periodontal disease, is capable of surviving and causing infection despite high levels of reactive nitrogen species found in the oral cavity due to its efficient nitrosative stress response. HcpR is an important sensor-regulator that plays a vital step in the initiation of the nitrosative stress response in many Gram negative anaerobic bacteria. We employ a combination of X-ray crystallography, SAXS, resonance Raman spectroscopy, UV-Vis spectroscopy, and molecular biology techniques to better understand this key regulator. Knockout of the hcpR gene in W83 P. gingivalis results in the inability of …

Orientia Tsutsugamushi Secretes Two Ankyrin Repeat-Containing Effectors Via A Type 1 Secretion System To Inhibit Host Nf-Κb Function, Sean M. Evans

Theses and Dissertations

Scrub typhus is a potentially fatal infection that threatens one billion persons in the Asia-Pacific region and is caused by the obligate intracellular bacterium, Orientia tsutsugamushi. How this organism facilitates its intracellular survival and pathogenesis is poorly understood. Intracellular bacterial pathogens utilize the Type 1 (T1SS) or Type 4 secretion system (T4SS) to translocate ankyrin repeat-containing proteins (Anks) into the host cell to modulate host cell processes. The O. tsutsugamushi genome encodes one of the largest known bacterial Ank libraries as well as Type 1 and Type 4 secretion systems (T1SS and T4SS), which are expressed during infection. In …

Amixicile Inhibits Anaerobic Bacteria Within An Oral Microbiome Derived From Patients With Chronic Periodontitis, Kane Ramsey

Theses and Dissertations

Periodontitis is a chronic inflammatory disease caused by pathogenic bacteria residing in a complex biofilm within a susceptible host. Amixicile is a non-toxic, readily bioavailable novel antimicrobial that targets strict anaerobes through inhibition of the activity of Pyruvate Ferredoxin Oxidoreductase (PFOR), a major enzyme mediating oxidative decarboxylation of pyruvate. Our study aimed to evaluate the efficacy of amixicile, when compared to metronidazole, in inhibiting the growth of bacteria present in a microbiome harvested from patients with chronic periodontitis.

Plaque samples were harvested from patients with severe chronic periodontitis and cultured under anaerobic conditions. The microbiomes were grown in the presence …

Study Of Molecular Interactions Of Glycosaminoglycans And Glycosaminoglycan Mimetics With Their Protein Targets, Daniel K. Afosah

Theses and Dissertations

Glycosaminoglycans (GAGs) are complex linear chain carbohydrate molecules found on virtually all animal cell surfaces. Owing to their negatively charged nature, GAGs interact with a number of different proteins. Thus, although they have great potential as therapeutic agents, their apparent promiscuous interactions increase their side effect risk. GAG mimetics, including GAG oligosaccharides and non-saccharide GAG mimetics (NSGMs) are viable approaches to address this. This work discusses sulfated benzofuran thrombin inhibitors with submaximal protease inhibition, sulfated diflavonoid inhibitors of plasmin and GAG oligosaccharides with selectivity for human neutrophil elastase (HNE).

Anticoagulants are very important for the treatment of thrombotic diseases. The …

A Systems Biology Approach For Predicting Essential Genes And Deciphering Their Dynamics Under Stress In Streptococcus Sanguinis, Fadi El-Rami

Theses and Dissertations

Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities.

Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in …

Drinking Motives Underlying Internalizing And Externalizing Pathways To Alcohol Misuse In College Students, Jeanne Savage

Theses and Dissertations

Alcohol misuse, including heavy episodic use and negative consequences, is a major public health concern and a particular problem among college students. The etiology of alcohol misuse is not well resolved, with multiple and often contradictory factors implicated in its development. Genetic factors influence alcohol misuse but few specific genes have been identified. A potential reason for these challenges is that alcohol misuse is phenotypically and genetically heterogeneous; that is, there are multiple causal pathways underlying its development. Previous typologies have suggested that distinct internalizing and externalizing pathways are involved, with corresponding differences in profiles of personality, temperament, and comorbid …

Contribution Of A Class Ii Ribonucleotide Reductase To The Manganese Dependence Of Streptococcus Sanguinis, John L. Smith

Theses and Dissertations

Manganese-deficient Streptococcus sanguinis mutants exhibit a dramatic decrease in virulence for infective endocarditis and in aerobic growth in manganese-limited media. Loss of activity of a manganese-dependent, oxygen-dependent ribonucleotide reductase (RNR) could explain the decrease in virulence. When the genes encoding this RNR are deleted, there is no growth of the mutant in aerobic broth culture or in an animal model. Testing the contribution of the aerobic RNR to the phenotype of a manganese transporter mutant, a heterologous class II RNR from Lactobacillus leichmannii called NrdJ that requires B₁₂ rather than manganese as a cofactor was previously introduced into an …

The Role Of Human Msc Derived Exosomes In The Treatment Of Periodontal Diseases, Sonia S. Talegaonkar

Theses and Dissertations

Periodontal disease affects 47% of Americans over 30. Characterized by microbial dysbiosis and unregulated inflammation, severe periodontitis causes degradation of bone and soft tissue around teeth. Current treatments have limited regenerative outcomes and frequent reinfection by harmful bacteria. Human mesenchymal stem cells (hMSCs) have been shown to promote wound healing and tissue regeneration. Many therapeutic benefits of hMSCs are due to their secretome products, like exosomes. Our long-term goal is to develop periodontal therapies with hMSC exosomes. The objectives of this study were to determine the effect of hMSC-derived exosomes on cellular activity of hMSCs and investigate whether hMSC exosome …

Po2 Dependence Of Oxygen Consumption In Skeletal Muscle Of Hypertensive And Normotensive Rats, Habiba Shah

Theses and Dissertations

Human essential hypertension affects over 75 million people in the United States, and can lead to death due to its several serious health complications such as hypertension-related cardiovascular disease. The purpose of this research was to understand how hypertension could cause physiological changes to the microcirculation, specifically the PO₂ dependence of oxygen consumption (VO₂) in skeletal muscle of normotensive and hypertensive rats. The Spontaneously Hypertensive Rat (SHR) strain was used as the diseased model, and Wistar-Kyoto (WKY) rats were used as controls to conduct this study. The SHR strain develops hypertension between 5-6 weeks after birth with …

Epigenetic Editing To Validate Findings From Methylome-Wide Association Studies Of Neuropsychiatric Disorders, Robin F. Chan

Theses and Dissertations

DNA methylation is necessary for learning, memory consolidation and has been implicated in a number of neuropsychiatric disorders. Obtaining high quality and comprehensive data for the three common forms of methylation in brain is challenging for methylome-wide association studies (MWAS). To address this we optimized a panel of enrichment methods for screening the brain methylome. Results show that these enrichment techniques approach the coverage and fidelity of the current gold standard bisulfite based techniques. Our MBD-based method can also be used with low amounts of genomic material from limited human biomaterials. Psychiatric disorders have high prevalence and are often chronic …

Type 2 Immune Responses In The Context Of Helminth Infection, Asthma, Dendritic Cells, And Myeloid Derived Suppressor Cell Function, Sheela Ruby Damle

Theses and Dissertations

Type 2 (T_H2) immune responses evolved to respond to helminth parasite infections by the production of T_H2 cytokines, which stimulate anti-helminth immunity. Macrophage migration inhibitor factor (MIF) is a pleiotropic cytokine, which is produced by many cell types. We demonstrate that mice deficient in MIF have enhanced clearance of a helminth parasite. MIF deficiency in CD4⁺ T cells was found to be the most important for mediating parasite clearance. We mimicked MIF deficiency by administering an inhibitor of the MIF tautomerase activity, sulforaphane, and this also increased parasite clearance (Section I).

T_H2 immune …

The Influence Of Genetic And Environmental Factors On Quit Attempt In Adolescent And Young Adult Twins, Gladys Langi

Theses and Dissertations

The purpose of this study was to examine the genetic and environmental influences on lifetime quit attempt in three US adolescent and young adult twin samples (N total = 6,322). The study utilized a common-contingent-causal (CCC) model to estimate these factors for lifetime quit attempts, after accounting for the factors for lifetime cigarette use and cigarettes per day. The study also examined age and sex differences, as well as the degree of relationship between these smoking phenotypes. The results demonstrated significant genetic influences for lifetime quit attempts in adolescents and young adults. No sex differences were observed for the contributions …

Mast Cell Activation By Diverse Stimuli Can Be Suppressed By Steroid Therapy And Targeting The Fyn-Stat5b Cascade, Anuya Paranjape

Theses and Dissertations

Mast cells are critical effectors of allergic disease that can be activated by numerous stimuli. We have examined mast cell control by the inflammatory cytokine, IL-33, as well as IgG. In the first study reported here, we found that the synthetic glucocorticoid, dexamethasone, potently and rapidly suppressed IL-33-induced cytokine production from murine bone marrow–derived and peritoneal mast cells, as well as human mast cells. Dexamethasone also antagonized IL-33-mediated enhancement of IgE-induced cytokine production and migration. Although dexamethasone had no effect on IL-33-induced phosphorylation of MAP kinases or NFκB p65 subunit, it antagonized AP-1 and NFκB-mediated transcriptional activity. Finally, intraperitoneal administration …

Tissue Factor Expression, Regulation, And Signaling In Human Airway Cells, Michael D. Davis

Theses and Dissertations

Rationale: Tissue Factor (TF) is a transmembrane glycoprotein that canonically functions as the initiator of the coagulation cascade. Increased levels of TF have been associated with inflammatory airway diseases. Since lipopolysaccharide (LPS) is known to elicit and inflammatory response in airway epithelium, we hypothesized that airway epithelial cells release TF when exposed to LPS. Since TF aids in local wound healing, we also hypothesized that inhibition of TF would decrease NHBE growth. The specific aim of this work was to evaluate the effects of LPS exposure on TF production and release from airway epithelia and determine the signaling pathways involved. …

Identification Of Expression And Function Of The Glucagon-Like Peptide-1 Receptor In Gastrointestinal Smooth Muscle, Alexander T. May

Theses and Dissertations

In response to ingestion of nutrients, enteroendocrine L cells secrete the incretin hormone, glucagon-like peptide-1 (GLP-1), to enhance glucose-dependent insulin release. Therapies related to GLP-1 are approved for type 2 diabetes. The GLP-1 receptor (GLP-1R) is expressed in cells of the gastrointestinal tract and elsewhere. In pancreatic beta cells, GLP-1R are coupled to the Gs/cAMP/PKA pathway. The expression and function of GLP-1R in gastrointestinal smooth muscle are not known. Aim. To test the hypothesis that GLP-1 regulates smooth muscle function by acting on GLP-1R expressed on smooth muscle. Methods. Smooth muscle cells (SMC) were isolated and cultured. Expression of GLP-1R …

Deletion Of Cardiac Mir-17-92 Cluster Increases Ischemia/ Reperfusion Injury Via Pten Upregulation, Meeta B. Prakash

Theses and Dissertations

The miR-17- 92 cluster is necessary for cell proliferation and development of the cardiovascular system. Deletion of this cluster leads to death in neonatal mice. The role of this cluster still needs to be defined following ischemia and reperfusion. Methods and Results: Adult male mice were injected with Tamoxifen- was to induce inducible cardiac-specific miR-17- 92-deficient (miR-17- 92-def: MCM:TG:miR-17- 92 flox/flox ) and wild type (WT: MCM:NTG:miR-17-92 flox/flox ) mice were subjected to 30 minutes of myocardial ischemia via left anterior descending coronary artery ligation followed by reperfusion for 24 hours. Post I/R survival (48%) and ejection fraction were reduced, …

Characterization Of Staphylococcal Nuclease And Tudor Domain Containing Protein 1 (Snd1) As A Molecular Target In Hepatocellular Carcinoma And Non-Alcoholic Steatohepatitis, Nidhi H. Jariwala

Theses and Dissertations

CHARACTERIZATION OF STAPHYLOCOCCAL NUCLEASE AND TUDOR DOMAIN CONTAINING PROTEIN 1 (SND1) AS A MOLECULAR TARGET IN HEPATOCELLULAR CARCINOMA AND NON-ALCOHOLIC STEATOHEPATITIS

Nidhi Jariwala, PhD

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Integrative Life Sciences

Virginia Commonwealth University, 2017

Devanand Sarkar, M.B.B.S., PhD.

Associate Professor, Department of Human and Molecular Genetics

Virginia Commonwealth University

Richmond, Virginia

SND1, a subunit of the miRNA regulatory complex RISC, has been implicated as an oncogene in hepatocellular carcinoma (HCC). Oncoprotein SND1 regulates gene expression at a post-transcriptional level in multiple cancers including hepatocellular carcinoma (HCC). …

Hydrogen Sulfide Regulation Of Kir Channels, Junghoon Ha

Theses and Dissertations

Inwardly rectifying potassium (Kir) channels establish and regulate the resting membrane potential of excitable cells in the heart, brain and other peripheral tissues. Phosphatidylinositol- 4,5-bisphosphate (PIP2) is a key direct activator of ion channels, including Kir channels. Gasotransmitters, such as carbon monoxide (CO), have been reported to regulate the activity of Kir channels by altering channel-PIP2 interactions. We tested, in a model system, the effects and mechanism of action of another important gasotransmitter, hydrogen sulfide (H2S) thought to play a key role in cellular responses under ischemic conditions. Direct administration of sodium hydrogen sulfide (NaHS), as an exogenous H2S source, …