• A Data-Mining Strategy That Identifies Drugs and Genes Associated With Anti-Cancer Drug Sensitivity

      Schleifer, Robert John; Department of Pharmacology and Toxicology (2017)
      The success of cancer therapy for patients often hinges on the responsiveness of the cancer cells to therapeutics. Drug resistance to anti-cancer therapeutics, both intrinsic and acquired, has important clinical and scientific significance. Identification of drug resistance genes using traditional methodologies and translation of those findings to the clinic has proven challenging. We developed a predictive data mining-based bioinformatic framework using public patient data and high-throughput cancer cell drug screening data. This information was used for genome-wide rankings of putative drug resistance genes. Prominent drug resistance genes (e.g. ABCB1, EGFR, and AXL) were successfully identified by the pipeline, additional genes hypothesized to be novel drug resistance genes were then investigated. Experimental confirmation of the novel genes using knockdown technologies indicated a propensity for of decreased proliferation/viability of cancer cells and increased sensitivity for anticancer compounds after knockdown much like known drug resistance genes. We then assessed the potential of each gene as an anti-cancer therapeutic target by exploring how gene knockdown behaved with clinical anticancer compounds. A second arm of the data-mining pharmaco-genomic strategy involved identification of candidate compounds that decrease expression of drug resistance genes. Using the drug resistance gene AXL as a proof-of-concept, three compounds were identified that decreased AXL expression at sub-micromolar concentrations. These compounds were characterized using microarray and cell signaling studies and found to decrease cell cycle signaling as well as activity of the Akt, mTOR, and ERK pathways. This study illustrates a novel approach for rapid and efficient identification of drug sensitivity genes or gene expression altering compounds utilizing bioinformatic data-mining.
    • Deciphering mechanisms of DNA methylation regulation by depletion of the DNA methyltransferases and SETD2

      Tiedemann, Rochelle Lee; Department of Biochemistry and Molecular Biology / Cancer Center (2015)
      DNA methylation (5mC) is a stabile epigenetic mark that confers differential function for gene expression and chromatin accessibility dependent on the context and locality of the mark. Promoter regions populated by CpG islands (CGIs) are highly unmethylated while the remaining ∼80% of CpGs are methylated and distributed across gene bodies, repetitive and transposable elements, and intergenic regions of the genome. The presence and/or absence of particular histone modifications also dictate the patterning of 5mC genome-wide. In cancer, a reversal of 5mC patterns occur in which hypermethylation of tumor suppressor gene CGIs confers gene silencing, and hypomethylation of repetitive and transposable elements contribute to genomic instability. The mechanisms by which 5mC becomes aberrantly regulated in cancer remain unknown. In this study, direct and indirect mechanisms of 5mC regulation were investigated. To understand the direct regulation of 5mC genome-wide, we depleted cell line models of the DNA methyltransferases (DNMTs) that are responsible for establishing (DNMT3A, DNMT3B, DNMT3L) and maintaining (DNMT1) 5mC patterns. Profiling of 5mC patterns on the Illumina HumanMethylation450 BeadChip revealed a unique antithetical relationship between DNMT1 and DNMT3B for the regulation of both 5mC and DNA hydroxymethylation (5hmC) across gene bodies. DNMT3B mediated nonCpG methylation, while DNMT3L influenced the activity of DNMT3B toward nonCG versus CpG site methylation. DNMT3B depletion induced 5mC patterns that closely resemble those observed during cellular differentiation and occurred across gene bodies of highly expressed, H3K36me3-marked genes. SETD2, the histone methyltransferase responsible for H3K36me3 establishment across active gene bodies, was determined to influence the guidance of DNA methylation genome-wide through an indirect mechanism. SETD2 knockout induced widespread loss of H3K36me3 that did not coincide with changes in 5mC. However, paradoxical gains in H3K36me3 significantly induced hypermethylation and upregulation of underlying genes. Genes marked exclusively by the poised enhancer mark, H3K4me1, were commonly targeted for this epigenetic phenotype. DNA methylome profiling of loss-of-function SETD2 mutated clear cell renal cell carcinoma, papillary renal cell carcinoma, and lung adenocarcinoma tumors confirmed the predominance of the hypermethylation phenotype upon loss of SETD2. Collectively, these studies provide novel insight to understanding the regulatory mechanisms by which 5mC patterns are conferred.
    • DEFINING THE ROLE OF TROPOMYOSIN-1C IN CARGO TRANSPORT IN DROSOPHILA

      Boggupalli, Shankarappa Devi Prasad; Department of Cellular Biology and Anatomy (Augusta University, 2020-05)
      Cell polarity is the asymmetric organization of different organelles in a cell, including the plasma membrane and cytoskeleton. Such organization results from asymmetric sorting of proteins, either post-translationally or pre-translationally by messenger RNA localization. In Drosophila oocytes, posterior localization of oskar mRNA is required for germplasm assembly and establishing antero-posterior polarity. oskar mRNA is transported by Kinesin, however the adaptor that links Kinesin to oskar mRNA was not known. In Aim 1 of this thesis, we demonstrate that a novel isoform of Tropomyosin, namely Tm1C, binds directly to kinesin and functions as the adaptor in linking kinesin to oskar mRNA. Oskar expression is limited to female germline, however Tm1C is also expressed in male flies. This suggests that there might be additional cargoes for Tm1C. We attempted to identify novel cargoes of Tm1C by performing a proteomic assay in Drosophila S2 cells. Apart from Khc, we identified Supernumerary limbs (Slmb) as the main interacting partner. Our further investigation of Slmb suggests that it might not be a cargo. Instead, Slmb which is a component of E3 ubiquitin ligase, might regulate the expression of Tm1C. In Aim 2 of the thesis, we show that Slmb regulates the levels of Tm1C by ubiquitinating it and facilitating its degradation by the Proteasome.
    • A descriptive study of hospital nurses' valuation of quality assurance

      Showman, Lonnie; School of Nursing (1984-05)
      The purpose of this study was to describe hospital nurses' valuation of quality ~ssurance. It replicateq Edwardson and Anderson's (1983) study through use of their questionnaire. One nursing department located in a southern community was studied. A total of 78 nursing employees supplied data regarding valuation of quality assurance. Three distinct groups supplied the data: staff nurses who worked Monday through Friday; management nurses; and nurses who worked a special staffing option, the Baylor Plan, on weekends. The Metropolitan Nurses for Quality Assurance Nursing Survey Questionnaire, developed by members of the Metropolitan Nurses in Quality Assurance of Greater Minneapolis and St. Paul, was used to measure valuation of quality assurance. Data were analyzed descriptively~ The study hypotheses proposed by Edwardson and Anderson did not appear. to be supported. Nurses who had participated in formal quality assurance activities within the last year were not more likeiy to want to write care standards for their specialty area or engage in peer review.
    • A Descriptive Study of Student Attrition Patterns in Georgia Nursing Programs

      Brandon, Marsha Ann; Department of Physiological and Technical Nursing (1975-05)
    • Design, Synthesis, and Initial Evaluation of D-Glyceraldehyde Crosslinked Gelatin-Hydroxyapatite as a Potential Bone Graft Substitute Material

      Florschutz, Anthony V; Institute of Molecular Medicine and Genetics (2012-07)
      Utilization of bone grafts for the treatment of skeletal pathology is a common practice in orthopaedic, craniomaxillofacial, dental, and plastic surgery. Autogenous bone graft is the established archetype but has disadvantages including donor site morbidity, limited supply, and prolonging operative time. In order to avoid these and other issues, bone graft substitute materials are becoming increasingly prevalent among surgeons for reconstructing skeletal defects and arthrodesis applications. Bone graft substitutes are biomaterials, biologies, and guided tissue/bone regenerative devices that can be used alone or in combinations as supplements or alternatives to autogenous bone graft. There is a growing interest and trend to specialize graft substitutes for specific indications and although there is good rationale for this indication-specific approach, the development and utility of a more universal bone graft substitute may provide a better answer for patients and surgeons. The aim of the present research focuses on the design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite composites for potential use as a bone graft substitutes. After initial establishment of rational material design, gelatinhydroxyapatite scaffolds were fabricated with different gelatin:hydroxyapatite ratios and crosslinking concentrations. The synthesized scaffolds were subsequently evaluated on the basis of their swelling behavior, porosity, density, percent composition, mechanical properties, and morphology and further assessed with respect to cell-biomaterial interaction and biomineralization in vitro. Although none of the materials achieved mechanical properties suitable for structural graft applications, a reproducible material design and synthesis was achieved with properties recognized to facilitate bone formation. Select scaffold formulations as well as a subset of scaffolds loaded with recombinant human bone morphogenetic protein-2 were implanted ectopically in a rodent animal model and histologically evaluated for biocompatibility, degradation, and bone formation in vivo. The gelatin-hydroxyapatite scaffolds retained dimensional structure over 28 days and did not elicit any undesirable systemic or local effects. Distinct areas of mineralization and osteoid/bone were noted in all the implanted scaffolds and quantitative differences were primarily dependent on the presence of hydroxyapatite.
    • Detection of Single Base Substitutions in DNA

      Hallowes, William Cannon; Department of Cell and Molecular Biology (1987-12)
    • Determinants of Participant and Health Promotion Activities in Rural Caregivers

      Easom, Leisa R.; Department of Physiological and Technological Nursing (2003-05)
      Rural elderly caregivers, a rapidly growing segment of our population, are particularly at risk for adverse health outcomes. Caregiving is difficult work and can be exhausting physically, mentally, and spiritually for the caregiver. The purpose of this study was to examine the potential relationships between perceived self-efficacy, perceived barriers and personal factors (functional/physical health, emotional health, folk home remedy behavior, and spirituality) and engagement in health promotion practices in rural, elderly caregivers. The probability sample consisted of 80 rural, elderly caregivers (71 female; 9 male) ranging in age from 65 to 84 years. Each was interviewed via telephone using a self-report questionnaire. A model of health promotion for rural, elderly caregivers based on Pender’s Health Promotion model was tested with multiple regression analyses. The proposed model accounted for 19% of the explained variance of health promotion activities. An interesting finding was the high level of frequency of engagement in health promotion activities except for exercise. Surprisingly, folk home remedy behavior did not impact engagement in health promotion activities in these rural elderly caregivers. While 99% of the caregivers in this sample reported using at least one folk home remedy in the last year, these data suggest that the caregivers utilized these remedies in addition to the reported health promotion activities. Emotional health was a significant positive correlate of engagement in health promotion activities suggesting that emotional health is an important factor for a healthy lifestyle in the rural, elderly caregiver. Future research should include the examination of specific health promotion domains in rural elderly caregivers. Additionally intervention studies with longitudinal designs are needed for this population. Implications for theory development and community-based interventions are presented.
    • Determinants of participation in health promotion activities in rural elderly caregivers.

      Easom, Leisa R.; Medical College of Georgia (Augusta University, 2003-05)
      Rural elderly caregivers, a rapidly growing segment of our population, are particularly at risk for adverse health outcomes. Caregiving is difficult work and can be exhausting physically, mentally, and spiritually for the caregiver. The purpose of this study was to examine the potential relationships between perceived self-efficacy, perceived barriers and personal factors (functional/physical health, emotional health, folk home remedy behavior, and spirituality) and engagement in health promotion practices in rural, elderly caregivers. The probability sample consisted of 80 rural, elderly caregivers (71 female; 9 male) ranging in age from 65 to 84 years. Each was interviewed via telephone· using a self-report questionnaire. A model of health promotion for rural, elderly caregiyers based on Pender's Health Promotion model was tested with multiple regression analyses. The proposed model accounted for 19% of the explained variance of health promotion activities. An interesting finding was the high level of frequency of engagement in health promotion activities except for exercise·. Surprisingly, folk home remedy behavior did not impact engagement in health promotion activities in these rural elderly caregivers. While 99% of the caregivers in this sample reported using at least one folk home remedy in the last year, these data suggest that the caregivers utilized these remedies in addition to the reported health promotion· activities. Emotional health was a significant positive correlate of engagement in health promotion activities suggesting that emotional health is an important factor for a healthy lifestyle in the rural, elderly caregiver. Future research should include the examination of specific health promotion domains in rural elderly caregivers. Additionally intervention s~udies with longitudinal designs are needed for - this population. Implications for theory development and community-based interventions are presented.
    • Determinants of quality of the caregiving relationship

      Sauter, Maranah A.; Determinants of quality of the caregiving relationship (1996-10)
    • DETERMINING THE MECHANISM OF EGALITARIAN-MEDIATED MRNA TRANSPORT IN DROSOPHILA

      Goldman, Chandler; Biomedical Sciences
      The establishment of cell polarity is critical for performing complex functions including division and migration. As such, the loss of polarity is implicated in many diseases including cancers. To establish polarity, many cell types rely on the asymmetric sorting of messenger RNAs or mRNAs. These mRNAs are held in a translationally-repressed state until reaching their destinations. Upon arrival, translation is allowed to commence, giving rise to spatially restricted proteins. Often, mRNAs are transported to their destinations along microtubules via linkage to one of the sub families of microtubule motors, Dynein or Kinesins. The mechanism by which mRNAs are linked to these motors is unknown for the vast majority of localizing mRNAs. Drosophila oocytes and embryos display a great number of mRNAs that are localized to specific regions. The protein Egalitarian (Egl) has been shown to directly bind several mRNAs and participates in their microtubule-based transport by promoting linkage to cytoplasmic Dynein. In Aim 1 of this thesis, we aim to determine the mechanism by which Egl and its interacting partners, Dynein light chain (Dlc/LC8), and Bicaudal D (BicD), tether mRNAs to the Dyenin motor for transport. Dlc is required for Egl homodimerization, which promotes binding to mRNAs. BicD then preferentially associates with mRNA-bound Egl and links the complex to the Dynein motor. In Aim 2, we further investigate Egl’s role in mRNA transport by determining the critical amino acid residues within its RNA binding domain required for mRNA association.
    • Determining the Molecular Basis for Depressed Ventricular Contractile Function in Cardiac Neural Creat-Ablated Chick Embryos

      Hatcher, Cathy J; Department of Biochemistry and Molecular Biology (1998-01)
      Ablation of the cardiac neural crest (CNC A) in embryonic chicks at Hamburger- Hamilton stages 8-10 results in a high incidence of persistent truncus arteriosus, a congenital heart defect characterized by a single arterial trunk leaving the heart. Decreased ventricular contractility, which could be due to defects at the level of the contractile apparatus or in the excitation-contraction coupling (ECC) process, has been documented in this model. The first hypothesis that the decrease in isometric force produced per cross-bridge by Triton-skinned ventricular muscle preparations was due to inhibition of the contractile apparatus caused by excessive microtubules was not supported by the data: (1) The total microtubule content and the maximum calcium-activated forc generated by ventricular muscle strips of hearts from embryonic day (ED) 15 CNC A and sham-operated control embryos was not significantly different. (2) Destabilization of microtubules in ventricular muscle strips did not improve the force-producing capability of the contractile apparatus in CNCA embryos. Therefore, microtubules do not appear to be the cause for decreased isometric force production. The second hypothesis that the decrease in ventricular contractility was due to an improperly functioning FKBP1 2 .6 , a ryanodine receptor (RyR) modulatory protein which plays a role in ECC, was supported by the data: (1) FKBP1 2 .6 was present in comparable amounts in hearts from ED 15 CNCA and sham-operated embryos, (2) Dissociation of FKBP1 2 .6 from the RyR had significant effects on intact twitch force and calcium-induced calcium release from the sarcoplasmic reticulum in ED IS sham-operated, but not CNCA embryos. Therefore, FKBP1 2 .6 is present, but not functional in hearts from CNCA embryos, and, thereby, plays a major role in the impaired ECC in these hearts.
    • Development and Characterization of a Closed-Head Mild Traumatic Brain Injury Model

      Alverson, Katelyn; Clinical Laboratory Sciences (Augusta University, 2020-12)
      Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and places an enormous economic burden on both families and health care systems that provide support for survivors. The majority of TBI cases are deemed mild (mTBI) and go undetected due to the less discernable signs and symptoms. However, there is increasing evidence that mTBI can lead to detrimental chronic consequences. Unfortunately, the mTBI research field is still in its infancy. We set out to develop a model of closed-head mTBI that recapitulated mTBI in the clinic. Using a murine controlled cortical impact model, we show no structural damage, increased edema, behavioral deficits, cell death and decreased synapses in the acute time after the mTBI. We also evaluated the chronic behavioral changes from two weeks to three months post TBI. All in all, our mTBI model showed significant cellular changes, but did not give robust chronic behavioral results. A secondary outcome of our study was the evaluation of a potential therapeutic: remote ischemic conditioning (RIC). Acutely, RIC improved edema, behavioral outcomes, cell death, and synapse loss. Overall, our study does identify key areas that should be recapitulated in further development of the model: no structural damage, little to no edema, cell death and decreased synapses, and behavioral changes. This model also requires further investigation into the chronic consequences of mTBI as well as the use of RIC.
    • THE DEVELOPMENT AND TESTING OF AN OBSERVATION RATING SCALE TO MEASURE BEHAVIORAL DEVELOPMENT OF PREMATURE, VENTILATOR DEPENDENT INFANTS

      Burch, Sharon; School of Nursing (1987-12)
      The purpese of this study was to develop and test an observational a~sessment Seal~ that could be used to measure the behavioral development of premature, ventilator dependent infants. The major goal of this study was to establish interrater reliability and content and criterion-related validity for this.scale. Two research questions guided the development of this instrument: 1) Can certain behaviors reflecting developmental stability of a premature. infant be observed and measured? and 2) Are certain clusters of behaviors indicative of the degree of physiological instability of premature infants? The sample consisted of 20 premature infants: Group I (n=lO) infants of 26-29 weeks of gestation and ventilator dependent, and Group II (n=lO) infants of 32-34 weeks of gestation and not ventilator dependent. These infants were observed prior to a nursing intervention and after a nursing int~rvention. Interrater reliability, content validity and criterion-related validity were obtained. The results indicated that the behaviors characteristic of premature infants of 26-29 weeks of gestation and ventilator dependent can be identified, observed and reliably measured.
    • Development of a model for evaluation of the wear and cutting efficiency of nickel-titanium engine-driven files

      Foster, Jan Marie; Medical College of Georgia (Augusta University, 2006-12)
      Diabetic patients often develop hypertension as a result of enhanced renal sodium reabsorption and altered sodium balance. Because nitric oxide (NO) is a critical mediator of sodium han.dling, our goal was to elucidate the diabetes-induced alterations in the NO system. The medullary thick ascending limb (mT AL) of Henle's loop expresses all three isoforms of NO synthase (NOS1, NOS2, and NOS3). Under physiological conditions, NO inhibits sodium reabsorption in the mTAL, while superoxide (02•) promotes it. The balance between NO and 0 2- is critical for controlling sodium reabsorption in the TAL, which is responsible for reabsorbing twenty to thirty percent of filtered sodium. Therefore, the objectives of this study were to examine the regulation ofNOS enzyme expression, NOS enzyme activity, NO production, and NO bioavailability as well·as the influence of NO on sodium reabsorption in the mT AL under diabetic conditions. Diabetes is a state of increased 0 2- production. 0 2- scavenging reduces NO bioavailability. We hypothesized that NO production would be enhanced in the mTAL during diabetes. We found that although NO production was enhanced in the mTAL during diabetes, NO bioavailablity was blunted due to increased 0 2- production. NOS 1 and NOS3 activities are regulated by changes in phosphorylation status. Immunohistochemical analysis suggests that protein phosphatase 2 B (PP2B; calcineurin) is upregulated in the mTAL in diabetes. We hypothesized that NOS activity and NO production was upregulated in a PP2B-dependent manner in the mTAL during diabetes. We found that NOS 1 and NOS2-dependent NO production were increased in a PP2Bdependent manner. Additionally, we examined the role ofNO in the regulation of sodium reabsorption in the mTAL during diabetes. We hypothesized that NO production would blunt sodium reabsorption. NOS 1 and NOS2-derived NO production blunted sodium reabsorption in the mT AL under diabetic conditions, but only in the presence of a 02- inhibitor to prevent scavenging of NO. In conclusion, we have revealed important mechanisms that are critical to the regulation ofNO production in the mTAL during diabetes.. These studies also enhanced our understanding of the regulation of sodium transport by NO in the mTAL, specifically under diabetic conditions.
    • Development of a model for evaluation of the wear and cutting efficiency of nickel-titanium engine-driven files

      Ford, Michael W.; Department of Oral Biology & Microbiology (Augusta University, 1995-05)
    • Development of a radioimmunoassay for serum testosterone

      LaPointe, John G.; Department of Endocrinology (1970-11)
    • Development of an Instrument for Assessment of Auditory Hallucinations in Schizophrenia

      Frederick, Jane A; Department of Physiological and Technological Nursing (2000-03)
      The purpose of this study was to develop and assess the psychometrics of an instrument for the assessment of auditory hallucinations in schizophrenia and other psychiatric disorders. Development of the Auditory Hallucination Assessment Scale (AHAS) was guided by Albert Ellis’ reformulated model of Rational Emotive Behavior Therapy, the ABCD model. Applied to auditory hallucinations, the ABCD model asserts that distress and maladaptive coping behaviors are consequences not of the hallucination itself, but of the individual’s beliefs about the hallucination. An initial draft of the AHAS was submitted to an expert panel for assessment of content validity. The revised version of the AHAS is a 32 item self-report. Likert scale items describe characteristics, beliefs and attitudes about hallucinations and consequences of hallucinations. The psychometric properties of the AHAS were studied in a convenience sample of 151 clients in psychosocial rehabilitation outpatient day programs in two Georgia counties. Participants also completed two other hallucination scales, and one depression scale. Exploratory factor analysis was used to determine the underlying factor structure of the items and to assess the construct validity of the AHAS. The factor analysis resulted in a three-factor model which delineated three differing clinical symptom patterns of auditory hallucinations. The factors were labeled Troublesome Voices, Dangerous Voices, and Nurturing Voices. Rather than dividing the hallucinatory experience into three cognitive components as in the theoretical model, the factors reflected connections between the characteristics, beliefs, and consequences of auditory hallucinations. Thus, each of the constructs of the theoretical model operates within each of the resulting factors. The Troublesome Voices Factor consists of items indicating distressing auditory hallucinations and attempts to cope with them. The items on this factor indicate self-awareness and reflect behavioral or emotional reactions to the voices. The items on the Dangerous Voices Factor reflect beliefs that the voices are bad, hostile and powerful. The Nurturing Voices Factor items indicate that the individual experiences soothing and comforting voices. Finally, it is clinically significant that all participants in the sample, ninety-one percent of whom had schizophrenia or schizoaffective disorder, were able to complete the AHAS without difficulty.
    • Development of an instrument for assessment of auditory hallucinations in schizophrenia

      Frederick, Jane A.; Medical College of Georgia (Augusta University, 2000-04)
      The purpose of this study was to develop and assess the psychometrics of an instrument for the assessment of au~itory hallucinations in schizophrenia and other psychiatric disorders. Development of the Auditory Hallucination Assessment Scale (AHAS) was guided by Albert Ellis' reformulated model ofRational Emotive Behavior Therapy, the ABCD model. Applied to auditory hallucinations, the ABCD model asserts that distress and maladaptive coping behaviors are consequences not of the hallucination itself, but of the individual's beliefs ~bout the hallucination. An initial draft of the AHAS was submitted to an expert panel for assessment of content validity. The revised version of the AHAS is a 32 item self-report. Likert scale items describe characteristics, beliefs and attitudes about hallucinations and consequences of hallucinations. The psychometric properties of the AHAS were studied in a convenience sample of 151 clients in psychosocial rehabilitation outpatient day programs in two Georgia counties. Participants also completed two other hallucination scales, and one depression scale. Exploratory factor analysis was used to determine the underlying factor structure of the items and to assess the construct validity of the AHAS. The factor analysis resulted in a three-factor model which delineated three differing clinical symptom patterns of auditory hallucinations. The factors were labeled Troublesome Voices, Dangerous Voices, and Nurturing Voices. Rather than dividing the hallucinatory experience into three cognitive components as in the theoretical