• 5' Flanking Sequence Mutations Associated With Low Expression of Fetal Y-Globin Genes

      Brinson, Eleanor Campbell; Department of Cell and Molecular Biology (1988-06)
    • 96 plays a role in the virulence of C. jejuni

      Rathbun, Kimberly M; Department of Medicine (2009-05)
      Campylobacter jejuni is a gastrointestinal pathogen of humans but part of the normal flora of poultry. C. jejuni therefore grows well at both 37°C and 42°C. Proteomic studies on temperature regulation in C. jejuni strain 81-176 revealed the upregulation at 37°C of CJ0596, a predicted periplasmic chaperone that is similar to proteins found to be involved in outer membrane protein (OMP) folding and virulence in other bacteria. The cj0596 gene was highly conserved in multiple strains and species of Campylobacter (24 in total), implying the importance of this gene. To study the role CJ0596 plays in Campylobacter pathogenesis, a mutant derivative of strain 81-176 was constructed in which the cj0596 gene was precisely deleted. This mutant was complemented by restoring the gene to its original chromosomal location. The mutant strain demonstrated a decreased growth rate and lower final growth yield, yet was more motile than wild-type. The cj0596 mutant also showed altered levels of several outer membrane proteins (OMPs), and changes in membrane-associated characteristics (antimicrobial sensitivity, autoagglutination, and biofilm formation). In either single or mixed infections, the mutant was less able to colonize mice than wild-type. Purified, recombinant CJ0596 had peptidyl-prolyl cistrans isomerase (PPIase) activitty, but did not functionally complement an E. coli surA mutant. These results suggest that C. jejuni CJ0596 is a PPIase and loss of CJ0596 alters phenotypes that have been shown to be related to the pathogenesis of the bacterium.
    • A HERMENEUTIC PHENOMENOLOGICAL APPROACH TO EXPLORING THE LIVED EXPERIENCES OF PARTICIPANTS IN GEORGIA’S P-20 COLLABORATIVES

      Maple, Carol Willyn; Gamble, Phyllis; McCoy, Felina; Department of Advanced Studies and Innovation (Augusta University, 2020-04)
      This research effort used a hermeneutic phenomenological approach to investigate 1) What are the lived experiences of participants in Georgia’s P-20 Collaboratives? and 2) How are regional P-20 Collaboratives using mutual resources and continuous professional development to meet the needs of all stakeholders? Data provided by representatives from school systems (P-12s), colleges and universities (IHEs), Regional Education Service Agencies (RESAs), and State Education Agencies (SEAs) via a qualitative questionnaire, online discussion boards, contextual documents, and convening observations were analyzed to explore the perceived benefits and challenges of participation in Georgia’s P-20 Collaboratives and to examine the effectiveness of the regional Collaboratives in meeting the mission statement. Three emergent themes derived from the data were: 1) Mutually beneficial outcomes are derived from networking and sharing resources, but are hindered by low and inconsistent attendance by participants, 2) Diverse perspectives needed for effective reciprocal learning are limited by issues with focus, commitment, regular communication, and consistent participation by the right stakeholders, and 3) The majority of the respondents (68%) perceived that the regional collaboratives were effective in meeting the mission. However (14%) suggested improvements and (14%) felt that the mission statement lacked clarity.
    • A HERMENEUTIC PHENOMENOLOGICAL APPROACH TO EXPLORING THE LIVED EXPERIENCES OF PARTICIPANTS IN GEORGIA’S P-20 COLLABORATIVES

      McCoy, Felina Rae; Department of Advanced Studies and Innovation (Augusta University, 2020-05)
      This research effort used a hermeneutic phenomenological approach to investigate 1) What are the lived experiences of participants in Georgia’s P-20 Collaboratives? and 2) How are regional P-20 Collaboratives using mutual resources and continuous professional development to meet the needs of all stakeholders? Data provided by representatives from school systems (P-12s), colleges and universities (IHEs), Regional Education Service Agencies (RESAs), and State Education Agencies (SEAs) via a qualitative questionnaire, online discussion boards, contextual documents, and convening observations were analyzed to explore the perceived benefits and challenges of participation in Georgia’s P-20 Collaboratives and to examine the effectiveness of the regional Collaboratives in meeting the mission statement. Three emergent themes derived from the data were: 1) Mutually beneficial outcomes are derived from networking and sharing resources, but are hindered by low and inconsistent attendance by participants, 2) Diverse perspectives needed for effective reciprocal learning are limited by issues with focus, commitment, regular communication, and consistent participation by the right stakeholders, and 3) The majority of the respondents (68%) perceived that the regional collaboratives were effective in meeting the mission. However (14%) suggested improvements and (14%) felt that the mission statement lacked clarity. Keywords: P-20 collaboratives, collaboration, hermeneutic phenomenology, teacher preparation, regional partnerships, professional development, teacher quality
    • A HERMENEUTIC PHENOMENOLOGICAL APPROACH TO EXPLORING THE LIVED EXPERIENCES OF PARTICIPANTS IN GEORGIA’S P-20 COLLABORATIVES

      Gamble, Phyllis J.; Department of Advanced Studies and Innovation (Augusta University, 2020-05)
      This research effort used a hermeneutic phenomenological approach to investigate 1) What are the lived experiences of participants in Georgia’s P-20 Collaboratives? and 2) How are regional P-20 Collaboratives using mutual resources and continuous professional development to meet the needs of all stakeholders? Data provided by representatives from school systems (P-12s), colleges and universities (IHEs), Regional Education Service Agencies (RESAs), and State Education Agencies (SEAs) via a qualitative questionnaire, online discussion boards, contextual documents, and convening observations were analyzed to explore the perceived benefits and challenges of participation in Georgia’s P-20 Collaboratives and to examine the effectiveness of the regional Collaboratives in meeting the mission statement. Three emergent themes derived from the data were: 1) Mutually beneficial outcomes are derived from networking and sharing resources, but are hindered by low and inconsistent attendance by participants, 2) Diverse perspectives needed for effective reciprocal learning are limited by issues with focus, commitment, regular communication, and consistent participation by the right stakeholders, and 3) The majority of the respondents (68%) perceived that the regional collaboratives were effective in meeting the mission. However (14%) suggested improvements and (14%) felt that the mission statement lacked clarity. Keywords: P-20 collaboratives, collaboration, hermeneutic phenomenology, teacher preparation, regional partnerships, professional development, teacher quality
    • A Mixed-Methods Study on the Experiences and Beliefs of Teachers in Professional Development for the Implementation of Visible Learning

      Cunningham, Benton Willis; Department of Advanced Studies and Innovation
      School improvement ultimately rests in the hands of teachers, and the balance of teaching and evaluation of learning is the method for sustained success. In his 2009 book, Visible Learning (VL), John Hattie acknowledges this statement and contends that the majority of teachers know what works due to reflexive teaching praxis. Many schools across the nation are implementing the VL framework through professional development (PD). This study will focus on the implementation of the VL framework through PD in the high-performing Southeastern school district of Suburban County. A mixed-methods inquiry was conducted to learn more about teachers’ perceptions of VL PD efficacy and preferences for future PD. Qualitative results showed teacher competency improved after VL PD but knowledge of VL remained incomplete. Quantitative results were not statistically significant but the use of the Teacher Mindframes Survey (Murphy, 2020) demonstrated internal reliability for this new instrument. Overall, findings suggested future VL PD should focus on generating greater teacher buy-in. One way to do this is by integrating VL PD with Adult Learning Theory (ALT) models and practices, as VL implementation can be enhanced through the addition of academic coaches and the incorporation of ALT practices. The researchers concluded additional studies are needed to determine best practices for implementing VL in schools. Keywords: Visible Learning, Adult Learning Theory, and professional development
    • A Molecular Basis of Chemoresistance in Bladder Cancer

      Lahorewala, Sarrah; Biochemistry and Cancer Biology (Augusta University, 2020-12)
      Background: In advanced bladder cancer (BC), development of resistance to the frontline chemotherapeutic drugs Gemcitabine and Cisplatin contributes to the poor prognosis of patients. Newly discovered chondroitinase, HYAL-4 V1 (V1), drives malignant transformation in BC. We evaluated V1’s role and the downstream molecules involved in the mechanistic regulation of chemoresistance in BC. Experimental Design: HYAL-4 expression was evaluated by RT-qPCR and IHC in metastatic muscle-invasive BC patients who received Gemcitabine plus Cisplatin chemotherapy. HYAL-4 wild-type and V1 were stably expressed or silenced in three BC and one normal urothelial cell line. Transfectants were analyzed for Gemcitabine and Cisplatin sensitivity, and for Gemcitabine influx and efflux to determine the mechanism of Gemcitabine resistance. The effect of cytidine deaminase (CDA) inhibition on Gemcitabine sensitivity was evaluated in vitro and in xenograft models. Results: HYAL-4 expression was an independent predictor of disease-specific mortality and treatment failure in our clinical cohort, and stratified patients into higher risk for both those outcomes. V1-expressing BC and normal urothelial cells were resistant to Gemcitabine due to the upregulation of cytidine deaminase (CDA) expression and activity, resulting in increased Gemcitabine metabolism and efflux; treating cells with tetrahydrouridine (THU), a CDA inhibitor, abrogated the chemotherapeutic resistance. Gemcitabine-resistant V1 cells demonstrated increased expression of V1’s substrate CD44 and phosphorylated STAT3. Si-RNA mediated CD44 knockdown and STAT3 inhibition both sensitized cells to Gemcitabine in vitro. In xenograft models, treatment with a combination of Gemcitabine and THU completely inhibited tumor growth. Conclusions: This project discovered V1 as a novel determinant of Gemcitabine resistance and potential predictor of treatment response in BC. V1 drives resistance to Gemcitabine through CD44-STAT3 mediated upregulation of CDA, and inhibiting this pathway sensitizes tumor cells to the therapy in preclinical models of BC.
    • A NOVEL NETWORK BASED LINEAR MODEL FOR ENRICHMENT OF SYNERGISTIC DRUG COMBINATIONS

      Li, Jiaqi; Department of Physiology (Augusta University, 2021-07)
      Drug combination therapies can improve drug efficacy, reduce drug dosage, and overcome drug resistance with respect to cancer treatments. Current research strategies to determine which drug combinations have a synergistic effect rely mainly on clinical or empirical experience and screening predefined pools of drugs. Given the number of possible drug combinations, the speed and scope to find new drug combinations are very limited using these methods. Due to the exponential growth in these combinatorials, it is difficult to test all possible outcomes in the lab. Several large-scale public genomic and phenotypic resources that provide data from single drug-treated cells as well as data from small molecules deliver a wealth of cellular response information. This data gives opportunity to overcome limitations of the current methods. The development of a new strategy for advanced data processing and analysis that includes a computational prediction algorithm is highly desirable. Because of this, a program was written that predicts synergistic drug combinations using gene regulatory network knowledge and an operational module unit (OMU) system generated from single drug genomic and phenotypic data. As a proof of principle, we applied the pipeline to a group of anticancer drugs and demonstrated how the algorithm could help researchers efficiently find possible synergistic drug combinations using single drug data to evaluate all possible drug pairs.
    • A Systematic Review & Meta-analysis: The Role of Cytokines in Adult Women 18 Years or Older with Fibromyalgia

      Casseus, Karis; Nursing (Augusta University, 2022-05)
      Background: Fibromyalgia (FM) is a chronic disease characterized by widespread pain of no confirmed etiology. Evidence supports an association between neuroinflammation and a FM diagnosis. The purpose of this study was to compare pro-inflammatory cytokines levels between having a diagnosis of FM in adult women 18 years or older and adult healthy females. Examining this difference may help identify an objective measure for FM diagnosis in adult females. Based on the law of pain theory, we hypothesize a dysregulation of inflammatory cytokines in FM adult females. Research methods: The 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines were followed. Six electronic databases, PubMed, CINAHAL, Cochrane, PsycINFO, Web of Science, and clinicaltrials.gov, were used to identify studies. The primarily studied variable is blood cytokines, including TNF-alpha, IL-1β, IL-6, IL-8. Non-interventional studies and interventional studies or secondary data analysis studies investigating blood cytokines and FM in adult females were included. Screening and data collection were done in multiple stages with two data abstractors and a third reviewer. Each study was appraised for quality using a scoring tool by Shiao and Yu (2016) and the risk for bias assessment tool by Cochrane was adapted for case-control studies. A meta-analysis was conducted to pool data and compare pro-inflammatory cytokines and adult FM females using the random-effects model. Result: Overall, the standardized mean difference (SMD) and confidence interval showed FM women had significantly higher blood cytokine levels for IL-6 and IL-8 compared to healthy controls (SMD = .34, CI = .08 to .60, p = .01). These results withstood multiple sensitivity analyses. In contrary to previous findings, being overweight was not a moderator of the association between blood cytokine levels and having FM in adult women. The quality of the included studies was moderate to high and evidence of publication bias was minimal. Four cytokines were studies in which IL-6 and IL-8 were the only two cytokines that maintained significance during the various sensitivity analyses. Conclusion: Findings from this study may be used as a basis for future research, explicitly investigating the incorporation of IL-6 and IL-8 in the diagnosis of FM in adult women. Keywords: fibromyalgia, fibrositis, fibromyositis, central nervous system centralization, cytokines, interleukins, tumor necrosis factor.
    • Acquiring Situation Awareness through Hand-Off in a Critical Care Environment

      Holden, Tina; Nursing (Augusta University, 2019-12)
      Hand-off communication is associated with 80% of hospital errors. Situation awareness (SA) has been targeted as a strategy to reduce errors and enhance patient safety when providing hand-off communication. Few studies have focused on the influence of SA in hand-off communication in the intensive care unit where the risk of errors is high. The purpose of this study was to develop a substantive theory of critical care nursing hand-off. The study was guided by Endsley’s SA framework. A qualitative study design using Straussian grounded theory methods was used to develop a substantive theory related to critical care nursing hand-off. Data collection strategies included observation of 20 critical care nursing hand-offs followed by 34 semi-structured interviews and took place from 2017 to 2019 in a medical and surgical ICU at two academic tertiary care facilities. Data analysis was conducted using constant comparative analysis and was guided by Endsley’s model of SA. Results revealed that hand-off is a basic social process with a core category of handing-off awareness. The process contained four phases: interactive, reflective, maintenance, and preparatory. The interactive phase was characterized by communication between the giver and receiver of hand-off. During that phase, the 10 critical elements of hand-off were passed on to the receiver. These critical elements included the code status, past medical history, story, systems assessment, trends, changes, rationale, level of organ support, and anticipation. Handing off these elements in a way that flows with logical order affects awareness. Nursing behaviors of the giver associated with handing off awareness are linked to the critical elements. For the receiver, these behaviors include arriving prepared, reporting the critical elements, controlling flow, and making connections between the critical elements. Behaviors for the receiver include being an active listener, validating information, and asking questions within the flow of information. In the reflective phase, the resilient nurse bridges gaps in awareness. The maintenance phase is characterized by nursing actions that support hand-off information recall. In the maintenance phase, SA is maintained through artifacts. Artifacts are tools used by nurses to aid in the cognitive function of hand-off. The preparatory phase is characterized by information synthesis and organization. The four phases of hand-off are re-occurring and are influenced by individual and organizational factors. Individual factors include a nurse’s personal process, experience, socialization, and emotional intelligence. Organizational factors include unit policies, unit artifacts, and safety culture. Theory and research implications include the need for future research to further expand the framework of SA in hand-off, the use of qualitative methods to provide insight into complex areas of healthcare, and the need for educational interventions on SA hand-off. Practice implications include evaluation of current hand-off practices in the ICU and evaluation of organizational influences on hand-off. The study concludes that the theory of handing-off awareness in the ICU is a continuous process that occurs over four phases in a repetitive cycle that starts again with each shift change. The critical elements, flow, nursing behaviors, time, and external factors influence the ability of the nurse to achieve optimal SA.
    • Activation of a molecular chaperone (sigma 1 receptor) in a murine model of autosomal dominant retinitis pigmentosa.

      Barwick, Shannon; Biomedical Sciences (Augusta University, 2022-05)
      Retinitis pigmentosa (RP) is a devastating group of inherited retinal diseases that leads to visual impairment and eventually complete blindness. Currently no cure or treatment exists for RP patients, thus research into prolonging the vision in these patients is imperative. Sigma 1 receptor (Sig1R) is a promising small molecule target that appears to have neuroprotective benefits in the retina of fast degenerating mouse models. However, it is not clear whether Sig1R activation can provide similar neuroprotective benefits in more slowly progressing RP models, which are more similar to human patients. In this study, we examined whether Sig1R activation can be neuroprotective (i.e. prolong vision) in a more slowly progressing mouse model of autosomal dominant retinitis pigmentosa, RhoP23H/+. Current studies in the field give a brief overview of the RhoP23H/+ degeneration, but do not give a complete characterization of disease progression. Aim 1 of this study sought to further characterize the degeneration of the RhoP23H/+ mouse using 3 in vivo methods, Optomotor Response (OMR), Electrophysiology (ERG), and Spectral Domain-Optical Coherence Tomography (SD-OCT). A slow retinal degeneration was observed in both male and female RhoP23H/+ mice when compared to WT. Visual acuity showed a gradual decline through 10 months. Interestingly, visual acuity was still detectible, albeit significantly reduced through 10 months in both male and female mutant mice. Females appeared to have significantly lower visual acuity than males. These RhoP23H/+ mice showed a gradual decline in scotopic and photopic responses. Aims 2 and 3 sought to investigate the neuroprotective benefits of Sig1R activation in the RhoP23H/+ mouse model. Mutant mice were treated with a high specificity Sig1R ligand (+)-pentazocine ((+)-PTZ) 3x/week and examined using OMR, ERG, SD-OCT. A significant retention of visual function was observed in both males and females at 10 months of age, with treated females retaining ~50% greater visual acuity than non-treated mutant females. Using ERG, significant retention of scotopic and photopic b-wave amplitudes were observed at 6 months in both male and female mice treated with (+)-PTZ. Further, in vivo analysis of ONL thickness revealed a significant retention in both male and female treated mice. Histological studies using retinal cryosections showed significant retention of IS/OS length (~50%), ONL thickness, and number of rows of PRC nuclei at 6 months in both male and female (+)-PTZ-treated mice. Interestingly, electron microscopy revealed preservation of OS discs in (+)-PTZ treated mutant mice. Taken collectively, the in vivo and in vitro data represent the first report of Sig1R activation rescuing visual function and structure in the RhoP23H/+ mouse model. These results are promising and lay the framework for future studies to investigate Sig1R as a potential therapeutic target in retinal degenerative disease.
    • Activation of Arginase and the Endothelin System in Models of Ischemic Retinopathy

      Patel, Chintan; Department of Biochemistry and Molecular Biology; Department of Biochemistry and Molecular Biology (2014-07)
      Ischemic retinopathies, such as diabetic retinopathy (DR) and retinopathy of prematurity (ROP) are characterized by microvascular degeneration, followed by an abnormal hypoxia-induced neovascularization (NV). Although the triggering insult varies among the diseases, they share a common end result of capillary loss due to increased oxidative stress, cellular inflammation and vascular injury and dysfunction. We have linked activation of the urea hydrolase enzyme arginase to the latter complications in models of DR. Both arginase and nitric-oxide synthase (NOS) enzymes utilize L-arginine as substrate. NOS dysfunction due to limitations in L-arginine availability has been implicated in the pathogenesis of diabetic complications. Our studies in streptozotocin-induced diabetic mice and high glucose treated retinal ECs have demonstrated signs of retinal vascular activation and injury. These were associated with increased arginase activity and expression, decreased bioavailable nitric oxide (NO), increased superoxide formation and increased leukostasis. Blockade of the arginase pathway prevented these alterations, suggesting a primary role of arginase in retinal vascular dysfunction and injury. Our studies have also shown that endothelium-dependent retinal vasorelaxation was impaired in diabetic mice, however, deletion of arginase improved retinal vessel function and improved blood flow. During ischemic retinopathies, disturbances in retinal blood flow can result in vasoconstriction, ischemia, tissue hypoxia and formation of neovascularization (NV). Such alterations have been linked to development of ROP, a blinding disease that adversely affects premature infants due to oxygen-induced damage of the immature retinal vasculature resulting in pathological NV. Our studies using a mouse model of ROP, the oxygen-induced retinopathy (OIR) model indicate that a potent vasoactive and angiogenic factor endothelin (EDN) is responsible for pathological NV. Our analysis revealed significant increases in EDN1, EDN2 and endothelin A receptor (EDNRA) mRNA and EDN2 protein expression during ischemia. EDN2 was localized to endothelial cells and retinal glia in OIR retinas. Treatment of OIR mice with EDNRA blocker, BQ-123, significantly increased vessel sprouting resulting in enhancement of physiological angiogenesis and decreased pathological NV. OIR triggered a significant increase in STAT3 activation and VEGFA production and increased mRNA expression of angiogenic and inflammatory mediators, which were all reduced by BQ-123 treatment. These studies suggest that EDNRA activation during OIR promotes vessel degeneration and pathological NV. Collectively, both arginase and endothelins are increased in models of ischemic retinopathies. These two pathways could be interrelated through an unknown cross-talk mechanism that needs to be elucidated.
    • Activation of arginase and the endothelin system in models of ischemic retinopathy

      Chintan, Patel; Medical College of Georgia (Augusta University, 2014-07)
    • Activities and Perceived Outcomes of Nurse Case Managers: Building a Case Management Model for Rural Hospitals

      Anderson-Loftin, Wanda; School of Nursing (Medical College of Georgia, 1996-12)
      The primary purpose of this study was to describe the activities and perceived outcomes of nurse case managers in a rural hospital setting and the relationship of nurse case managers' education, experience, and age to activities and perceived outcomes. Results of the study will be used to further develop and refine a portion of the investigator-developed model of Nursing Case Management for Rural Hospit~ls which served as the study framework. Nurse case managers in non-federal, rural hospitals listed in the American Hospital Association's (1995) guide to U. S. hospitals were surveyed using an investigatordeveloped instrument. Psychometric qualities of the instrument were determined as part of the study. The sample (N = 302) consisted primarily of white, middle-aged females. The majority were ADN or BSN nurses who averaged two to three years experience in case management and 16 years experience in nursing. Descriptive, correlational, and multivariate statistics were used to analyze the data. Results indicated that individual advocacy was the most frequent activity, and comments suggested that nurse case managers were becoming aware of the centrality of advocacy to their practice and job satisfaction. The second most frequent activity was teaching, with clinical practice third. The most frequent pattern of activities reflected assessment and coordination of community resources through an advocacy role for the client while performing managed care/quality assurance activities. The top ten perceived outcomes were: (a) increased patient satisfaction, (b) reduced fragmentation of care, (c) reduced length of stay, (d) increased job satisfaction, (e) increased job enjoyment, (f) increased quality of life, (g) increased functional health, (h) increased self-care, (i) increased autonomy, and (j) attainment of goals within the time-frame for reimbursement. Two-thirds of the nurse case managers thought their activities prevented delays in care and provided clients with a regular source of care, thus increasing access to care. Other significant (p ~ .05) findings indicated: (a) ADN, BSN, and MSN nurse case managers engaged in more teaching than nurse· case managers with diplomas, (b) system advocacy was higher for MSN than for diploma, ADN, or BSN case managers, and (c) experienced nurse case managers engaged in more clinical practice than inexperienced nurse case managers.
    • Activity-dependent regulation of the dopamine transporter is mediated by Cam Kinase II signaling

      Padmanabhan, Shalini; School of Graduate Studies (2009-01)
      Dopamine signaling in the brain governs a variety of functions such as locomotor activity, reward, attention and working memory. The dopamine transporter (DAT) plays a crucial role in the clearance of extracellular dopamine and thus helps terminate dopamine neurotransmission. DAT is also the target for psychostimulant drugs of abuse and therapeutic agents. Changes in DAT expression occur in neuropsychiatric disorders such as attention deficit hyperactivity disorder (ADHD) and chro_nic psychostimulant use, and variability in DAT abundance is associated with differences in working memory. However, mechanisms regulating DAT expression are poorly understood. We tested the hypothesis that neuronal activity is one of the non-genetic determinants of DAT abundance. Chronic perturbations in neuronal firing, caused by pharmacological agents, significantly altered DAT expression and function in primary cultures of mesencephalic neurons. Pharmacological experiments showed that calcium entry through L-type voltage-gated calcium channels and calcium/calmodulindependent protein kinase II (CaMKII) activity played a role in activity-dependent changes in DAT expression. In order to further evaluate the role of CaMKII in DAT regulation, the effect of sustained depolarization, a stimulus often used to study activity-dependent changes in gene expression, on DAT expression was tested. Surprisingly, chronic KCl-induced depolarization decreased DAT expression and function. Measurement of CaMKII activity in dopam·ine neurons showed that chronic depolarization led to a decrease in CaMKI I activity, even in the presence of elevated intracellular calcium, due to activation of the serine/threonine protein phosphatase 2A. Moreover, increasing CaMKII activity in dopamine neurons by introducing a constitutively active CaMKII mutant caused a significant increase in DAT abundance while inhibiting CaMKII activity in dopamine neurons using a dominant-negative CaMKII mutant decreased DAT abundance suggesting that CaMKII activity is both sufficient and required to cause changes in DAT expression in a cell autonomous fashion. Taken together, our data demonstrate that CaMKI I activity can govern DAT expression and may play an important role in dopamine neurotransmission in the brain.
    • AN ACTOR-NETWORK VIEW OF THE CYBER DOMAIN’S EFFECTS ON DEMOCRATIZATION THROUGH ELECTIONS

      Garrett, Eric; Department of Social Sciences (Augusta University, 2020-05)
      Cyberspace conceptualizations include combinations of Internet infrastructure, the devices used to access it, and applications used to encapsulate or communicate data. Other conceptualizations are more abstract. Whether it directly enables democracy as a public sphere, drives economics in the private sector, or securitizes as a domain for information operations, or cyber warfare. These conceptualizations obscure understanding cyberspace’s first order effects on events, and second order understanding related to intelligence and security studies. The research question, can actor-network theory supply a robust theoretical framework to understand and describe cyberspace’s core qualities as a democratizing medium, will be examined in Kenyan, Nigerian, and Zambian use of cyberspace related to elections. Examination of these data points through four elemental characteristics of cyberspace, proliferation, evolution, “spatial hereness,” and linkability, within an actor-network theory will lead to a determination if the totality of cyberspace is a democratizing medium. Lastly, this paper will make general recommendations that can lead to greater understanding of cyberspace that can influence policy and decision making as well as encourage democratic maturity in cyberspace by applying the considerations gained from an actor-network theory perspective.
    • Acute non-genomic effects of testosterone in mesenteric microvessels: Role of peroxynitrite and prostaglandin E2

      Puttabyatappa, Yashoda; Department of Pharmacology and Toxicology; School of Graduate Studies (Medical College of Georgia, 2010)
      Prescription use of testosterone (T2) has increased 500% over the past 10 years, but the effects of T2 on cardiovascular function remain highly controversial. Moreover, even less is understood regarding the effects of T2 on the resistance vasculature. The purpose of our study was to identify the cellular / molecular basis of non-genomic T2 effects on arterioles isolated from the rat mesentery. We found that T2 induced a 36.45 ± 6% maximum relaxation of (phenylephrine-contracted) microvessels at pharmacological concentrations (EC50 4.56 ± 4.4 µM). In contrast, pretreating vessels with either indomethacin (10µM) or celecoxib (10µM) to inhibit COX-2 activity increased the sensitivity of these vessels to T2 by approximately 30-fold (EC50: 7.06 ± 2.53 nM and (6.05 + 0.002) x 10-8M, respectively), thus bringing the response closer to a more physiological concentration. These studies suggest at least 2 competing/complementary mechanisms of T2 action. The response to T2 was reduced significantly by pretreatment with 10µM flutamide (androgen receptor antagonist, 16.3 ± 5.9 %), 300µM L-NAME (non-selective NOS inhibitor; 5.3 ± 1.6 %), 100µM L-NPA (nNOS-selective inhibitor; 9.28 ± 1.54%), 50nM wortmannin (PI3K inhibitor; 15.32 + 4.47 %), 1mM uric acid (peroxynitrite scavenger; 9.94 ± 3.52%), or 10μM FeTPPs (peroxynitrite scavenger; 15.81 ± 3.14%), indicating that T2-induced relaxation involves production of NO and peroxynitrite via androgen receptor-dependent activation of the PI3-Akt signaling pathway and NOS (primarily the nNOS isoform expressed in VSM). T2-induced production of reactive nitrogen and oxygen species was confirmed by both fluorescence and electron paramagnetic resonance measurements. In addition to this novel vasodilatory mechanism, our experiments indicate that these vessels stimulates production of a contractile COX-2 metabolite (PGE2), suggesting that T2-stimulated PGE2 production functions as a feedback mechanism to oppose T2-induced relaxation. In summary, we propose that mesenteric microvessels exhibit a “ying-yang” response to T2: vasodilation via peroxynitrite and contraction via PGE2, and that it is the integration between these two opposing mechanisms that determines how T2 modulates tone in the resistance vasculature.
    • ADAM17 AND AGING-RELATED VASCULAR DYSFUNCTION

      Dou, Huijuan; Department of Physiology (1/25/2018)
      A disintegrin and metalloproteinase ADAM17 (tumor necrosis factor–converting enzyme) regulates soluble TNF levels. We tested the hypothesis that aging-induced activation in adipose tissue (AT)-expressed ADAM17 contributes to the development of remote coronary microvascular dysfunction in obesity. We found that the increased activity of endothelial ADAM17 is mediated by a diminished inhibitory interaction with caveolin-1, due to age-related decline in caveolin-1 expression in obese patients and mice or to genetic deletion of caveolin-1. Coronary arterioles (CA) and AT were examined in patients who underwent heart surgery. Excess, ADAM17-shed TNF from AT arteries in older obese patients was sufficient to impair CA dilation in a bioassay in which the AT artery was serially connected to a CA. CA and AT were also studied in 6-month and 24-month lean and obese mice. We found that obesity elicited impaired endothelium-dependent CA dilations only in older patients and in aged obese mice. Transplantation of AT from aged obese, but not from young or aged, mice increased serum cytokine levels, including TNF, and impaired CA dilation in the young recipient mice. In patients and mice, obesity was accompanied by age-related activation of ADAM17, which was attributed to vascular endothelium–expressed ADAM17. Additionally, ADAM17 mediates shedding of JAM-A (junctional adhesion molecule-A). We hypothesized that ADAM17 activation, via increased JAM-A shedding impairs flow mechanosensing and induces abnormal artery remodeling in aging. We found a reduced lumen diameter and increased wall thickness in AT of aged patients. ECs using plasmid JAM-A were aligned to flow direction earlier than GFP treated control cells. Site-directed mutagenesis was employed to generate JAM-A cleavage resistant mutants, we detected soluble JAM-A in the supernatants from cells transfected with plasmid JAM-A, but not from cells expressing mutant JAM-A plasmids. Importantly, soluble JAM-A is significantly increased in the supernatant from cells with combined action of plasmid JAM-A and recombinant ADAM17, when compared to cells with plasmid JAM-A alone. Collectively, our data revealed that age-related reduction in Cav-1 expression and subsequently increased the activity of endothelial ADAM17 led to excess TNF production, which acts remotely to promote coronary arteriole dysfunction. Whereas activation of ADAM17 in vascular endothelium mediates increased JAM-A shedding and causes ECs misalignment. Our data suggest that the combined action of TNF and JAM-A lead to development of CMD and its related vascular remodeling in older obese patients.