• EDTA Could Prevent Bisphosphonates-Related Osreonecrosis of Jaw after Traumatic Injury

      Awad, Mohamed; Department of Oral Biology (2016-03)
      The pathophysiological mechanism underlying Bisphosphonates related osteonecrosis of Jaw (BRONJ) remains poorly understood. Bisphosphonates localize to sites of osteoclast activity as Bisphosphonates bind Ca+2 in Tridentate manner. The aims of this study is to 1) prove the feasibility of in-vivo targeted removal of bisphosphonates from bone using chelating agents, and 2) use the targeted chelation to prevent BRONJ in rats. First, we tested whether local application of EDTA will reduce the bisphosphonate content in alveolar bone. Then, we tested the effect of EDTA in preventing BRONJ in eight Sprague Dawley rats that were treated intravenously for 12 weeks by Zoledronate [80 mg/kg; once per week]. Immediately after the last dose, the mandibular first and second molars were extracted on both sides, followed by application to the extraction site of EDTA on one side and saline on the other side in each animal for 10 minutes. Four weeks later, animals were sacrificed, and mandibles harvested for micro CT analysis and Extraction sites analysis. Exposure and necrosis of alveolar bone were evident on the PBS-treated extraction sites. Contralateral extraction sites treated with EDTA showed significantly improved mucosal covering and the signs of bone necrosis were significantly diminished both clinically and with micro-CT. We concluded that application of local chelating agents after tooth extraction maybe a new way for improving bone healing and preventing BRONJ.
    • Molecular Mechanisms Underlying ATP- And Adenosine Induced Microvascular Endothelial Barrier Preservation

      Batori, Robert; Vascular Biology Center (2016-03)
      Endothelial barrier integrity has critical importance in vascular homeostasis. Disruption of the endothelial cell (EC) barrier results in increased vascular permeability. Extracellular purines, ATP and adenosine (Ado) can restore the barrier function, involving the activation of myosin light chain phosphatase (MLCP). Both ATP and Ado increase protein kinase-A (PKA) activity, however a direct link between purine-induced EC barrier enhancement, MLCP and PKA was not described. Here we show that Ado and a stable analog of ATP, ATPγS, induced human lung microvascular EC (HLMVEC) barrier enhancement and PKA activation leads to decrease in MLC and MYPT1T696 phosphorylation. Surprisingly, PKA catalytic subunit (PKAc) depletion attenuates ATPγS, but not Ado-induced increase in transendothelial electrical resistance (TER), indicating that PKA activation is involved in ATP-induced EC barrier enhancement. Depletion of PKAc leads to increase in MLC and MYPTT696 phosphorylation in ATPγS challenged EC supporting the role of PKA in MLCP activation. To elucidate the role of PKA signaling in ATP-induced EC barrier enhancement we depleted several PKA-anchoring proteins (AKAPs). AKAP2 depletion attenuates ATPγS, but not Ado-induced TER increase. Furthermore, AKAP2 co-immunoprecipitates with MYPT1. This interaction was also confirmed by PLA. In conclusion ATP- and Ado-induced barrier enhancement requires different signaling with PKA promoting ATP-, but not Ado-induced EC barrier strengthening.
    • Neurovascular Injury After Retinal Ischemia Reperfusion Insult: Contrasting Roles Of Arginase Enzyme Isoforms

      Shosha, Esraa; Vascular Biology Center (2016-03-08)
      Purpose: We have previously shown the involvement of arginase enzyme in retinal neurovascular injury. The present study was undertaken to determine the distinct roles of arginase 1 (A1) and arginase 2 (A2) in neurovascular damage following ischemia/reperfusion (I/R) injury. Methods: We used wild type (WT) mice, A2 knock out mice (A2-/-) and mice lacking one copy of A1 (A1+/-). Western blotting, RT-PCR, vascular digests, immunofluorescence, Propidium Iodide (PI) labeling and electroretinography (ERG) were used to evaluate retinal injury and function. Results: I/R injury caused significant increases in A2 expression along with thinning of the neural retina, decreases in NeuN+ GCL neurons and formation of acellular capillaries. Increases in PI labeling and RIP-3 expression showed that cell death occurred by necroptosis. Neurovascular injury was accompanied by microglial activation along with increased expression of GFAP and impairment of the ERG. Neuronal cell loss, capillary degeneration, necroptosis, gliosis and ERG impairment were all significantly reduced by deletion of A2. On the other hand, A1 deletion exacerbated I/R-induced neuronal and vascular injury and further increased necroptosis and gliosis as compared with WT retinas. Conclusions: This study shows for the first time the different roles of arginase isoforms after I/R insult. I/R-induced necrotic cell death and gliosis are mediated by A2, whereas upregulation of A1 may play a role in limiting the pathology.
    • Perceptions of Nurses Regarding a Nurse Residency Program

      Shaver, Chelsey; Department of Physiological and Technological Nursing (2016-03)
      Background: The turnover rate among newly licensed registered nurses (NLRNs) is a healthcare issue with reported rates as high as 61% within the first year of practicing. Job satisfaction and organizational factors impact retention rates per recent studies. Purpose: The purpose of this study was to evaluate the perceptions of a nurse residency program (NRP) among newly licensed registered nurses (NLRNs) related to job satisfaction and retention. Methods: The Casey-Fink Graduate Nurse Experience survey was used to evaluate satisfaction of a NRP among NLRNs. This survey was distributed to 72 of the 88 nurse residents after they completed the nurse residency program on the NRU. Forty-three surveys were returned and 38 were included in the study. Results: The turnover rate of the 88 NLRNs who started the NRP was 8% after 20 months. Respondents reported overall satisfaction with the NRP in areas of skill level, job stress, work relationships and the organization. Areas noted for improvement included increased preparation for workload management and increased skill practice in code responses, IV insertion, and tracheostomy management. Conclusion/Recommendations for Practice: By improving job satisfaction, this NRP assisted the facility in maintaining turnover rates lower than those reported by evidence-based research. Participants reported more time on their home units would improve acclamation to workload management, though a tiered, increased patient load with increased acuity.
    • Reducing Tobacco Dependence: Evaluation of Tobacco Cessation Education on a Stroke Unit

      Cook-McKnight, Crystal; Department of Physiological and Technological Nursing (2016-03)
      Background: Tobacco use is the number one preventable cause of morbidity and mortality in the United States.It is a leading cause of cerebrovascular disease, and tobacco users are three times more likely to have a stroke compared to non-tobacco users. Georgia is among the highest rates of tobacco use and stroke in the U.S. Evidence based tobacco cessation interventions are available; however, they are are underutilized by clinicians. Purpose: The purpose of this project was to evaluate if a brief educational intervention related to tobacco cesssation interventions compared to the current practice impacted the attitudes, beliefs, intentions and knowledge of tobacco cessation counseling of healthcare professionals on a stroke unit.Methods: A 45 minute presentation based on a guideline with the most current recommendations was provided to clinicians on a stroke unit. A pre-post survey evaluated the knowledge, attitudes, beliefs and intentions of 29 nurses and a respiratory therapist related to tobacco cessation interventions in a tertiary care hospital in Georgia.Results:Tobacco counseling and treatment knowledge increased significantly from pre- to post-training. Average correct answers post survey was 76% versus the pre survey of 24%. Attitudes, beliefs and intentions were moderately correlated to improved self confidence. Conclusion: Overall, healthcare professionals exhibited improved tobacco cessation knowledge. Attitudes, beliefs and intentions were moderately impacted.
    • Salubrinal Mediated Fetal Hemoglobin Induction Through The PERK-eIF2α-ATF4 Signaling Pathway

      Lopez, Nicole; Department of Cellular Biology and Anatomy (2016-03)
      Sickle cell disease (SCD) is an inherited disorder caused by a point mutation in the β-globin gene affecting ~100,000 people in the United States. These individuals suffer from hemolytic anemia, pain, and progressive organ damage. The best therapeutic intervention in SCD is fetal hemoglobin (HbF) induction by pharmacologic agents, however, Hydroxyurea is the only FDA-approved drug with proven efficacy. The goal of this project is to discover drugs that induce HbF by novel mechanisms for SCD treatment. Salubrinal (SAL), a selective inhibitor of eukaryotic initiation factor 2α (eIF2α), was shown to increase HbF levels by enhancing γ-globin mRNA translation. These findings lead us to test the hypothesis that SAL activates the PERK-eIF2α-ATF4 stress response, as a mechanism of HbF induction in erythroid progenitors. Studies were conducted in K562 and erythroid progenitor generated from CD34+ stem cells treated with SAL (5, 12, and 18µM) for 48hr. RT-qPCR and western blot were used to measure γ-globin mRNA and HbF protein levels respectively. Preliminary data revealed a dose-dependent increase for HbF levels in K562 and erythroid progenitors treated with SAL. Flow cytometry showed an increase in the number of cells producing HbF (%F-cells). Furthermore, eIF2α and ATF4 levels were increased by SAL in K562 cells. These findings suggest SAL mediates HbF induction through eIF2α/ATF-4 signaling; future studies using the preclinical sickle cell mouse model will be investigated.
    • Understanding and Promoting Breastfeeding among African American Woman of the Rural South

      Stewart, Jessica Lynn; Department of Clinical and Digital Health Sciences (2016-03)
      African American women (AAW) have lower rates of breastfeeding (BF) than whites and other U.S. minority groups. Along with its many maternal and child health benefits, research indicates BF can reduce the risk of developing triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer with higher mortalities and incidence in AAW. Thus, increasing BF can be an important strategy for addressing breast cancer health disparities.This research seeks to ultimately determine whether increased awareness that BF reduces breast cancer and TNBC risk will positively alter AAW’s BF decision-making. A survey and an in-depth interview based on the Theory of Planned Behavior framework are used to examine AAW’s perceptions of breast cancer risk and prevention as well as their beliefs, attitudes and motivations that underlie BF decision-making. Preliminary analysis of 10 interviews to date showed that all of the participants had an intention and desire to BF, but many (n=6) lacked a realistic plan to manage BF and address expected barriers. When asked about breast cancer, most (n=8) demonstrated fear and avoidance of the topic. There was a general lack of knowledge, but excitement about the benefits of BF on TNBC prevention. Dissemination of this new evidence may be useful in guiding BF promotions among AAW. Also, there was a clear disconnect in BF intention versus action in this population. Further analysis will identify intervening factors that bridge the gap.