The John B. Graham Student Research Society
42nd Annual Student Research Day
January 27, 2010
Basic Science Oral Presentation (Harold C. Pillsbury Award):
Matt Skancke, Promoting Vasculogenesis
Public Health Oral Presentation (Harold C. Pillsbury Award):
Lauren M. Abbate, BMI and Waist Circumference and Incident Radiographic Knee Osteoarthritis in Women and Men: The Johnston County Osteoarthritis Project
Clinical Science Oral Presentations (2 winners) (Harold C. Pillsbury Award):
Matthew Gertsch, High Intraoperative Inspired Oxygen Does Not Reduce Postoperative Arterial Oxygen Saturation
Joshua Holt, Nitric Oxide Releasing Coatings Decrease Bacterial Colonization of External Fixation pins
Basic Science Poster Presentation (Harold C. Pillsbury Award):
Gitanjali Madan, Umbilical Cord Derived Mesenchymal Stem Cells Demonstrate Robust Osteoinduction and May Be An Ideal Source for Tissue-engineered Bone
Clinical Science Poster Presentation (Harold C. Pillsbury Award):
Elizabeth Hollin Calloway, 3-Dimensional Computed Tomography for Evaluation and Management of Children with Complex Chest Wall Anomalies: Useful Information or Just Pretty Pictures?
Public Health Poster Presentation (Kuno Award):
Bradley King, Nonmydriatic Digital Retina Camera Can Improve Diabetic Retinopathy Screening Rates in an Enhanced Care Clinic
List of Presented Abstracts
BASIC SCIENCE – Oral
Tacrolimus does not induce radiosensitization in vitro
Caster JM, Nepal D, Kettlsen D, DeMore N
UNC, Department of Surgery
Background: The clinical management of breast cancer recurrences varies by type and location but is in general poor. One type of recurrence, chest wall metastases following mastectomy, can be particularly difficult to manage clinically. Radiation and chemotherapeutic agents provide only modest benefit and there are often few surgical options. The utilization of radiosensitizers with radiotherapy may also provide a successful treatment option. Several novel compounds with modest antiangiogenic effects can induce radiosensitivity. We have shown that the FDA approved immunosuppressant Tacrolimus has modest antiangiogenic properties in vitro and in vivo.
Aim: To examine if Tacrolimus can increase the efficacy of ionizing radiation (IR) in killing cancer cells in vitro. Methods: Human breast (MCF-7, SUM185, SUM149), pancreatic (T3M4), and melanoma (SK178) lines were treated with 0, 1, or 10 uM Tacrolimus and irradiated 4 hrs later at 0, 2, 4, 6, or 8 grey. Drug was removed after 2 hrs and cells were incubated for 7-20 days until visible colonies formed. Colonies were then fixed, counterstained, and counted. Results: Neither dose of Tacrolimus increased the killing effects of IR in any of the cell lines. Discussion: The inhibition of calcineurin signaling by Tacrolimus is not sufficient to increase IR-mediated cell killing in vitro. However, it is possible that the modest antiangiogenic effect may increase tumor cell killing in vivo. Cancer cells are not dependent upon vascularization or the tumor/stroma microenvironment in these 2D assays. We are currently examining the effects of Tacrolimus on tumor cell killing by IR in spontaneous tumors in MMTV/Nu mice.
The heat shock protein and molecular chaperone alphaB-crystallin inhibits lysozyme amyloid formation
University of Cambridge
The formation of amyloid fibrils is associated with over 40 human disorders, including the fastest-growing illnesses in terms of affected populations and treatment-related cost. The ability to treat and prevent the diseases featuring amyloid is dependent on understanding the mechanism of amyloid deposition and how naturally-occurring cellular defenses prevent this process. We investigated the inhibitory effect of the small heat-shock protein (sHsp) alphaB-crystallin on in vitro lysozyme fibril formation, to allow for comparison of inhibition mechanisms of sHsps and the extracellular chaperones. Until recently, the elucidated protein quality control mechanisms existed primarily as intracellular processes. As much of aggregation and amyloid deposition occurs extracellularly, these intracellular chaperones would have little effect on secreted proteins that are vulnerable to fibrilization, and indeed, several extracellular chaperones have been found to impede this process. These extracellular chaperones appear to share behaviors with the sHsps, which stabilize but do not refold stressed proteins inside the cell. Biophysical studies of the extracellular chaperones and amyloidogenic lysozyme have shown inhibition of fibril formation to occur at substoicheometric ratios in a concentration dependent manner, involving binding and stabilization of an oligomeric or prefibrillar species. We used some of the same techniques, including H/D exchange mass spectrometry, ELISA analysis, and TEM, with the sHsp alphaB-crystallin to characterize its effect on lysozyme fibril formation and showed it to share a common mode of action with the known extracellular chaperones. It is hoped that elucidation of the common mechanisms used by cells to prevent amyloid deposition will enable the development of better therapeutics to treat diseases featuring amyloid fibrils.
William B. Hannah
Designing enhanced Factor IX for clinical trials in gene therapy
William B. Hannah, Tong Gui, Junjiang Sun, Jude Samulski, Tal Kafri, Paul Monahan
University of North Carolina
The major morbidity of congenitally deficient clotting factor IX (Hemophilia B) is arthropathy as a result of intraarticular hemorrhage. Gene therapy is a potentially powerful approach to treat arthropathy in these patients. Optimized gene expression cassettes and gain-of-function Factor IX (FIX) mutations can be employed in gene therapy to maximize FIX activity within the joint. Factor IX expression cassettes were engineered, incorporating a truncated cytomegalovirus (CMV) promoter, mvm intron, Bovine Growth Hormone polyadenylation region, and modified FIX variants: CMV FIXwt, CMV FIXopt, CMV FIXopt R338A, CMV FIXopt R338Q, and CMV FIXopt R338L (where wt represents wild-type FIX sequence and opt represents an optimized codon sequence). Human embryonic kidney cells (293 cells) were transfected with these constructs in vitro. Enzyme linked immunosorbent assays (ELISA) of the supernatant demonstrated that the optimized codon sequence may increase FIX expression. FIX activity assays suggest that each of the three single amino acid changes does in fact enhance FIX activity. CMV FIXopt R338L showed a dramatic increase in specific activity, 474 IU/mg, a value ten times the specific activity of the CMV FIXwt control (44 IU/mg). In addition, the latter two constructs have been incorporated into AAV vectors and the systemic expression of functional factor IX has been demonstrated after intravenous administration. These findings justify the generation of self-complementary adeno-associated virus serotype 5 (scAAV5) viral vectors incorporating each of these constructs, which will be individually injected into the hindlimb joints of mice. Histological staining and microCT imaging of joints will be utilized to assess the potential of these vectors to prevent bleeding-induced joint pathology in the mouse model.
Multi-Compartment Phantom for Modeling Normal Liver and Tumor Tissue
Patrick McNeillie, Andrew Kennedy, Andy Dezarn
Wake Radiology and Oncology Service, Raleigh NC & UNC Computer Science Department
To study the diagnostic tools and treatments used for hepatic cancer, researchers use in vitro models that mimic the human liver and tumor tissue, known as phantoms.
Endothelial and Cytokine stimulated differentiation of Hepatic Progenitor Cells
Malcolm Ross, David A Gerber, Lisa A Samuelson
UNC, Transplant Laboratory
Background: Our research team previously characterized an in vivo population of hepatocyte progenitor cells (HPCs) using Sca-1, a marker found on stem cells. Previous work shows that HPCs are bipotent, differentiating into mature hepatocytes and biliary cells. TGF- beta, transcription growth factor beta, has mito-inhibitory effects on hepatocytes in the uninjured liver. TNF-alpha, induces an increase in production of IL-6. Together these two cytokines produce important anti-apoptotic affects in the liver. Aims: Using an in vitro co-culture endothelial cell system we will investigate the ability of cytokines TGF-beta and TNF-alpha to selectively differentiate HPCs towards biliary cells or hepatocytes. The two cell lines used in co-culture with HPCs will be: C166, a mature endothelial cell line, and PY-4-1, a yolk-sac derived endothelial cell line. Results: Co-culture of HPC’s with a myocardial endothelial cell line, C166, and TGF- beta induces CK-19 and AFP expression. TNF-alpha at low concentrations induces CK-19 expression, which is lost at higher concentrations. Co-culture of HPC’s and PY-4-1 cells at all concentrations of TNF-alpha and TGF- beta induces a loss of the initial expression of CK-19 and AFP. Discussion: Varying concentrations of TGF- β can differentiate or de-differentiate HPCs co-cultured with c166, while treatment with TNF-alpha causes a loss of an initial biliary phenotype. With co-culture of HPC’s and PY-4-1 cells, TNF-alpha and TGF- beta at all concentrations induce a loss of the initial expression of biliary phenotype.
UNC, Plastic Surgery - Craniofacial / Maxillary Surgery
The biggest obstacle to tissue engineering is blood supply and if undetected, can lead to necrosis and loss of the tissue engineered skin. Vasculogenesis is the process of forming de novo blood vessels from endothelial progenitor cells (EPCs) and is necessary for the survival of tissue engineered skin. Blood vessel formation is guided by many physiological conditions including hypoxia and ischemia but primarily by increases in vascular endothelial cell growth factor (VEGF) signaling which facilitates the differentiation of EPCs into mature endothelial cells. The purpose of this study is to characterize the differentiation of EPCs into mature endothelial cells on different scaffolds when stimulated by exogenous concentrations of VEGF.
CD34+ cells extracted from umbilical cord blood (UCB) by magnetic bead filtering are excellent candidates as EPCs that can be induced via VEGF into an endothelial lineage. Filtered CD34+ cells were grown in a cytokine media and induced in a proprietary animal free endothelial maintenance media without VEGF or EGF on scaffolds. Endothelial colonies were noted after as little as seven days and continued to grow in size and number through day 21. Colony size and morphology was documented over 21 days via bright field microscopy and compared to data from established mature endothelial colonies. Results from four differentiation experiments indicate a positive relationship between CD34+ cells, exogenous VEGF and endothelial colony formation on synthetic scaffolds. Continued research is focused on patterning VEGF and other growth factors to orchestrate migration and differentiation of CD34+ cells.
Keratinogenesis from Human Umbilical Cord Mesenchymal Stem Cells Positive for SSEA4
Elizabeth C. Upton
UNC, Department of Plastic Surgery
Introduction: Human umbilical cord (hUC) mesenchymal stem cells (MSCs) have been differentiated into multiple mesodermal cell lines. In addition to mesodermal lineages, MSCs have been recently differentiated into ectodermal lineages such as neurons and glia using retinoic acid (RA) and bone morphogenetic protein-4 (BMP-4) stimulation. Stage-specific embyrogenic antigen 4 (SSEA4), an embryonic maker present on ectodermal cell lines, has also recently been demonstrated to be present on MSCs. We speculate that SSEA4+ hUCMSCs may represent a primitive cell population able to differentiate into keratinocytes. Our goal was to isolate SSEA4 positive hUCMSCs and develop a strategy to induce keratinogenesis. This finding has not been previously reported in the literature. Hypothesis: We hypothesized that SSEA4+ hUCMSCs can be induced to undergo keratinogenesis using a combination of RA and BMP-4 stimulation. Methods: HUC stroma was harvested using an explant technique, and cells were grown to confluence. SSEA4+ cells were then magnetically labeled, separated, and seeded into tissue culture wells at 5.0 x 103 cells/cm2. These cells were exposed to varying concentrations of RA in combination with BMP-4. After 14 days of culture, the cells were fixed with paraformaldehyde and immunostained for p63, K14, and Involucrin, markers of early, mid, and mature keratinogenesis, respectively. Results: Negative immunostaining for p63, K14, and Involucrin demonstrated no keratinocyte differentiation. Conclusions: In this study, SSEA4+ hUCMSCS were not induced to undergo keratinogenesis. However, we believe that part of this inability may have been secondary to an absence of proper environmental cues; we are currently repeating the experiments in organotypic culture (in the presence of fibroblasts, which provide a paracrine stimulatory effect on keratinocytes), which more nearly replicates the environment required for keratinocyte growth.
Kwun Wah Wen
Hsp90 & Hsp40 are required for the expression and anti-apoptotic function of KSHV K1
Kwun Wah Wen and Blossom Damania
UNC, Departments of Microbiology & Immunology
Kaposi sarcoma-associated herpesvirus (KSHV) is a member of the gammaherpesvirus family. It is the etiological agent of three different human cancers, Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). The far left-end of the KSHV genome encodes a unique transmembrane glycoprotein called K1. K1 possesses the ability to transform rodent fibroblasts and block apoptosis. K1 has also been shown to activate the PI3K/Akt/mTOR pathway in different cells.
Using tandem affinity purification (TAP), we identified heat shock protein 90beta (Hsp90beta) and endoplasmic reticulum (ER)-associated Hsp40 (Erdj3/DnaJB11), as cellular binding partners of K1. Interactions of K1 with Hsp90beta and Hsp40 were confirmed by co-immunoprecipitation in both directions. Furthermore, K1 also interacted with the Hsp90alpha isoform. We report that siRNAs directed against Hsp90beta and Hsp40, as well as pharmacological inhibitors of Hsp90 dramatically reduced K1 expression, suggesting that K1 is a client protein of these chaperones. Additionally, both Hsp90beta and Hsp40 were essential for K1’s anti-apoptotic function. Finally, we report that the Hsp90 inhibitors, 17-AAG and 17-DMAG, can suppress the proliferation of KSHV-positive PEL cell lines and exhibited IC50 values of 50nM and below.
In summary, our results suggest that K1 protein expression and anti-apoptotic function are dependent on the molecular chaperones, Hsp90 and Hsp40. We speculate that other oncogenic properties of K1 may also be regulated by these heat shock proteins. Our study also suggests that pharmacological inhibitors of Hsp90 (e.g. geldanamycin and its derivatives) may be efficacious for the treatment of KSHV-related malignancies.
CLINICAL SCIENCE – Oral
Preoperative General Pediatric Assessment for Children Requiring Dental Treatment Under General Anesthesia
Lauriane Auvergne BBA, Rocio Quinonez DMD, MS, MPH, Michael J. Steiner MD, J. Nicole Drawbridge BA, Michael Cowherd BS, and Michael W. Roberts DDS, MScD
UNC, Department of Pediatrics
Pediatric dentists treat patients under general anesthesia (GA) with complex restorative needs that preclude completion using in-office oral sedation. These children are initially referred to the General Pediatrics division (GP) for risk assessment prior to surgery. Our objective was to describe patients requiring GA for dental treatment and to determine the frequency and predictors of a change in preoperative or operative course due to the GP assessment. A retrospective case series design was used to evaluate all patients, ≤21 years of age, referred for dental preoperative evaluation between 7/1/05 and 6/30/08. Information extracted from medical records by three calibrated investigators included: demographics, medications, past medical history (PMH), past surgical history, family history, social history, physical examination, and American Society of Anesthesiology (ASA) class. A deflection was defined as a change in the recommendations for preoperative or operative care resulting from the GP assessment. Bivariate analysis and logistic regression were used to identify risk factors for deflection. The 955 identified subjects ranged from 9 months to 21 years of age (mean 5.6 years), and 70% had an abnormality on PMH, 47% had previous surgery, and 45% were currently taking medications. Fifteen percent were deflected; the most common reason was an antibiotic change or addition (32%), followed by additional diagnostic testing (26%). ASA classification >1 was the strongest predictor of deflection (p<000.1). In multivariate analysis, ASA=2 (OR 4.4, 95% CI 2.5-7.7) or ASA=3 (OR 15.3, 95% CI 8.2-28.3) increased deflection risk. In conclusion, pediatric referrals prior to GA identify problems that change preoperative course. Future recommendations for referrals should be based in part on predictors of deflection such as ASA classification.
Adam P. Campbell
Identification of Electrophysiological Markers of Damage in the Gerbil Cochlea during Electrode Implantation Using a Limited Stimulus Set and Direct Endoscopic Visualization
Adam P. Campbell, BA; Thomas A. Suberman, BA; Stefan Mlot, BA; John M. Pike, BS; Douglas C. Fitzpatrick, PhD; Oliver F. Adunka, MD
UNC, Department of Otolaryngology/Head and Neck Surgery
In cochlear implant candidates with residual hearing, the ipsilateral combination of electric and acoustic hearing (electric acoustic stimulation or EAS) has been shown to provide improved speech discrimination scores, especially in noise. However, retention of residual hearing is problematic, as it is often destroyed during electrode implantation. In previous animal experiments (see Suberman, Campbell et al.), intracochlear potentials (CM and CAP) were recorded using a wide range of stimuli as an electrode was advanced through the scala tympani. Small and reversible reductions in the potentials were identified as the electrode impinged on cochlear structures.
While these experiments were informative, time limitations during human cochlear implantation make use of a wide range of stimuli impractical. Consequently, we tested whether similar physiological effects could be obtained using a reduced stimulus set. To better understand the correlation between physiologic effects and electrode positioning, a micro-endoscope was utilized for direct visualization of the electrode during implantation.
Experiments were conducted in urethane-anesthetized, normal-hearing gerbils. Through an intact round window, a 0.3 mm diameter endoscope was used to visualize the electrode as it was advanced towards the basilar membrane via cochleostomy. At set intervals, intracochlear potentials were recorded at a single frequency and intensity. Once a decrease in response magnitude was observed, the electrode was withdrawn to determine if the effects were reversible. Cochlear damage was then identified histologically.
Electrophysiologic damage due to electrode impingement on intracochlear structures was readily detectable using a reduced stimulus set. In most cases, the damage was reversible upon electrode withdrawal. The site of electrode contact visualized with the endoscope correlated well with histological evidence of intracochlear damage.
These results indicate that a small stimulus set with potential intraoperative application can identify electrophysiologic markers of damage. The endoscopic imaging reinforces the idea that these markers are sensitive to impending intracochlear damage.
The Effect of Relaxation Therapy in Children with Functional Abdominal Pain in Quiescent Inflammatory Bowel Diseases (IBD)
Emilee Colella1,3, Miranda van Tilburg1, Sandy Kim2,3
- UNC Center for Functional GI and Motility Disorders, 2. UNC Department of Pediatrics, 3. UNC School of Medicine
Children and adolescents with quiescent inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) can experience abdominal pain similar to patients suffering from functional gastrointestinal disorders such as Irritable Bowel Syndrome (IBS). Functional abdominal pain can decrease quality of life, but effective treatment is neither widely available nor easily accessible. This project addresses designing and implementing a pilot study of home-based guided imagery versus placebo and will provide preliminary data to develop an in-depth investigation testing the effectiveness of guided imagery in reducing functional abdominal pain symptoms and increasing quality of life in pediatric IBD patients. Patients (age 9-17 years) diagnosed with IBD by a pediatric gastroenterologist and clinically determined to have abdominal pain consistent with IBS (not IBD exacerbation) were recruited from the UNC Pediatric IBD clinic. Patients were randomly selected to receive home-based guided imagery treatment (GIM) or placebo. Caregivers of patients completed questionnaires pre-treatment in clinic and post-treatment by phone interview regarding their child’s disease-related quality of life, functional disability, and abdominal pain. Expectation of treatment benefits and treatment adherence were assessed. 9 patients (mean: 14.2±2.7 yrs; 67% female) were recruited; six received GIM, three received placebo, and one child received both. Data analysis will be completed winter 2010 and will include patient demographics, credibility scores, and baseline measurement changes in quality of life, pain, and disability to post-treatment measurements, comparing subjects in the guided imagery versus placebo groups. Future studies will extend initial findings to ultimately decrease unnecessary treatment toxicity from medications utilized when abdominal pain is assumed to be due to disease exacerbation.
High Intraoperative Inspired Oxygen Does Not Reduce Postoperative Arterial Oxygen Saturation
Natalie Mackintosh, BS1, Matthew C. Gertsch, BS2, Harriet W. Hopf, MD3, Nathan L. Pace, MD, MStat, Julia White, RN
University of Utah, Department of Anesthesiology
INTRODUCTION: Use of high inspired oxygen (FiO2) intraoperatively has been shown to reduce surgical site infection (SSI) in colon surgery(1,2). Controversy remains regarding the side effects of high FiO2 particularly the degree of absorption atelectasis, which limits acceptance in lower risk patients(3). PEEP may abrogate absorption atelectasis. We therefore studied the effect of intraoperative FiO2 0.3 vs. >0.9 with and without PEEP on postoperative hypoxemia and need for supplemental oxygen in patients undergoing lower risk surgery.
METHODS: A double blind randomized 2x2 factorial design study was employed. After IRB approval and preoperative written informed consent, 100 subjects were randomized into 4 treatment groups (FiO2 >0.9 vs. 0.3, with and without PEEP). Except for FiO2 and PEEP, induction and maintenance of anesthesia were at the discretion of the anesthesia team. After 30 minutes in the PACU, supplemental oxygen was discontinued. Arterial oxygen saturation by pulse oximetry (SpO2) was then recorded after 15 min of breathing room air. If the subject’s SpO2 decreased to <90%, supplemental oxygen was added incrementally (starting with 0.5 Lpm) as needed to maintain SpO2>90%. The same procedure was followed 22-26 hours later.
RESULTS: All 100 subjects have completed the study. A non-parametric Exact Wilcoxon rank sum test demonstrated no statistically significant difference in postoperative supplemental oxygen use between groups (p>0.05).
DISCUSSION: The use of high inspired oxygen does not appear to lead to absorption atelectasis sufficient to increase postoperative hypoxemia. Therefore, it may be reasonable to employ high FiO2 even in lower risk surgery to reduce the risk of SSI.
1. Greif R, et al. NEJM 2000; 342: 161-7.
2. Belda F, et al. JAMA 2005; 294: 2035-42.
3. Duggan M. and Kavanaugh B. Anesthesiology 2005; 102:838-54
Nitric oxide releasing coatings decrease bacterial colonization of external fixation pins
Holt, J B; Hertzberg, B P; Weinhold, P S; Storm, W L; Schoenfisch, M H; Dahners, L E
UNC, Department of Orthopaedics
Bacterial infection of the pin tract represents the most common complication associated with external fixation. The use of xerogel films as a carrier device for anti-infectious agents represents a new paradigm in the design of antibacterial therapeutics. This study aimed to evaluate the antibacterial activity of NO releasing xerogel films applied to commercially pure titanium pins in a rat model.
This was accomplished through implantation of three different pins in three proximal tail vertebrae of each rat; one pin coated with NO releasing xerogel film, one pin coated with xerogel film only, and one control pin with no coating. Quantification of bacterial infection was performed 48 days post-operatively and the tissue-implant interface was inspected for clinical signs of infection at two discrete time periods.
All 15 rats survived until euthanization on postoperative day 48. There was no significant difference between weight at surgery (414.8±38.2g) and day 48 weight (429.4±51.7g).
Pin tract bacterial colony counts of the NO releasing group (170K±181K) were significantly lower than both the xerogel coated group (677K±675K) and the control group (1,181K±2,717K) 48 days postoperatively (p<0.05). No significant difference in colony counts were observed between the xerogel coated group and the control group. There were no NO releasing pin tracts that were given an infection score of >3 on postoperative day 28; the xerogel coated and control groups had 2 and 7 pins score >3 respectively. The number of NO releasing pins scoring greater than 3 was significantly lower than both the number of xerogel coated and control pins scoring > 3 even 28 days after surgery (p<0.05).
Our study results provide evidence that NO releasing xerogel coatings can reduce bacterial colonization of external fixation pins up to 48 days post-implantation, despite the fact that the xerogel coatings have likely released the majority of their NO during the initial five days. Additionally, qualitative evaluation of infection on postoperative day 28 revealed significantly reduced signs of infection associated with NO releasing pins when compared to controls. These results taken together suggest that NO releasing xerogel coatings can inhibit bacterial colonization of external fixation pins not only during the initial postsurgical period, but more importantly, seven weeks postoperatively.
Prophylactic nasal intermittent positive pressure ventilation (NIPPV) versus prophylactic nasal continuous positive airway pressure (NCPAP) for preterm infants with Respiratory Distress Syndrome
Kelly Salter, Matthew Laughon, Brigitte Lemyre, Carl Bose
UNC Department of Pediatrics, Division of Neonatology
BACKGROUND: Premature infants with respiratory distress syndrome (RDS) often need intubated ventilatory support, which is associated with bronchopulmonary dysplasia (BPD). Nasal continuous positive airway pressure (NCPAP) has been shown to be an effective and non-invasive mode of respiratory support, and nasal intermittent positive pressure ventilation (NIPPV) is being explored as a possible alternative primary treatment for RDS.
OBJECTIVE: To perform a systematic review of existing literature to examine the risks and benefits of prophylactic NIPPV versus prophylactic NCPAP alone for preterm infants.
METHODS: We searched MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, CINAHL, controlled-trials.com, clinicaltrials.gov, and abstracts from the Pediatric Academic Society 2000-2009 meetings . Two authors reviewed abstracts and full texts to identify eligible trials. We extracted data from eligible trials and entered it into Review Manager software (Version 5), and we calculated risk ratios or mean weighted differences for the outcomes of interest. Outcomes explored included mortality at 28 days, BPD, need for mechanical ventilation, pneumothorax, intraventricular hemorrhage, necrotizing enterocolitis, nasal septal injury, sepsis, and duration of hospital stay.
RESULTS: Three trials (n=248 infants) were identified and included. Meta-analysis of these studies showed a significantly reduced risk of BPD (RR 0.29; 95% CI 0.10 to 0.86) and need for intubation (RR 0.51; 95% CI 0.32 to 0.82) in infants treated with NIPPV. Mortality, NEC, pneumothorax, sepsis, nasal septal injury, IVH, and duration of hospital stay were reported infrequently or not at all, thus not allowing for meta-analysis of these outcomes.
CONCLUSIONS: Prophylactic NIPPV appears to have benefits over prophylactic NCPAP alone for the treatment of RDS in premature infants. NIPPV was shown to decrease the incidence of BPD and decrease failure of nasal respiratory support, therefore decreasing the need for mechanical ventilation. More studies are needed to confirm the benefit and to assess relatively uncommon risks such as pneumothorax and IVH.
Pediatric Renal Transplantation and the Cylex ImmuKnow: A Single Center Experience
Z. Smith, C. Wang, H. Stewart, R. Detwiler, L. Kearns, N. Bitner, L. McCoy, D. Gipson, K. Gibson, T. Kozlowski, B. Layton, W. Primack, M Ferris
UNC School of Medicine
Introduction: The Cylex ImmuKnow assesses cell-mediated immunity by measuring ATP generation in lectin (PHA)- stimulated CD4 cells. We present our experience with Cylex in pediatric renal transplant patients. Methods: All patients aged <19 years at time of transplant and now less than 25 years with Cylex levels measured between 11/2006 and 4/2009 were included. Patients with very low Cylex levels (<100 ng/ml ATP) or very high levels (>600 ng/ml ATP) were retrospectively evaluated for infection or rejection within the 3 months following the result respectively. We divided the cause of ESRD by glomerular versus not. Acute rejection was biopsy verified. Viral infection was defined as either a clinical syndrome or a positive PCR in blood or urine. Results: 366 Cylex tests were obtained in 50 patients with the following characteristics: 24(48%) males, 23(46%) White, 22(44%), Black and 5(10%) other race. 33(46%) had non-glomerular disease, current mean age of 14.2 8 4.9, and mean age at transplant 9.9+/-5.2. The mean Cylex level was 359.7+/-186.4. Of the 12 patients with low levels (<100ng/ml) 5 had viral infections (42%). None of the 8 patients with very high Cylex levels had acute rejection, but one developed parvovirus and another developed BK virus infections. In this cohort, 3 (6%) patients had acute rejections despite therapeutic Cylex levels within the previous two months. The total cost of the Cylex tests in this cohort was between USD109,068 and USD133,224 based upon a test cost of USD298 and test charge of USD364. Conclusions: Cylex levels in most of these patients were in therapeutic range. 40% of patients with very low levels developed viral infections as did 25% of patient with very high Cylex levels. Episodes of acute rejection were not associated with abnormal levels of this test. Cost-benefit analysis of this test is currently underway.
Thomas A. Suberman
Residual Hearing Preservation during Cochlear Implantation in Gerbils with Noise Induced, High-Frequency Hearing Loss
Thomas A. Suberman, BA; Adam P. Campbell, BA; Craig A. Buchman, MD; Oliver F. Adunka, MD; Douglas C. Fitzpatrick, PhD
UNC, Department of Otolaryngology/Head and Neck Surgery
Desired Result: To create an animal model that mimics human hearing loss such that established markers could be used to create a near real-time monitoring system for improved cochlear implant insertion in humans
Hypothesis: Damage to high-frequency portions of the cochlea that are initially accessed during an insertion of cochlear implant will be identifiable in the residual responses to low frequency sounds.
Background: Thus far we have shown that cochlear microphonics (CM) and cochlear action potentials (CAP) can be used as markers to identify damage to intracochlear structures. Now that we have established reliable markers, we turn our focus to the clinical relevant scenario of high-frequency noise loss.
Methods: Gerbils are exposed to high-pass noise sufficient to produce high-frequency hearing loss, while preserving low frequency hearing. After two weeks of rest, an electrode is placed at the round window and the CAP and CM are measured in response to free field tone bursts. The electrode is then advanced and measurements are taken and compared with those of the round window. When a change in potentials is noted, the electrode is withdrawn to determine if the damage is reversible. Finally, the cochlea is fixed and histology is used to identify the extent of damage caused by both the noise and the electrode.
Results: In response to noise exposure, animals show equivalent bilateral hearing loss, as evidenced by increase in thresholds of CAP and CM in recordings taken at the round window. Furthermore, changes in the CAP and CM are detectable even when damage due to electrode impact is in the high-frequency region of the cochlea.
Conclusion: CM and CAP remain reliable markers of intracochlear damage in gerbils with noise induced, high-frequency hearing loss.
The impact of hydroxyurea therapy on the progression of osteonecrosis of the femoral head in patients with sickle cell disease
Lindsay Veit, Rupa Redding-Lallinger
UNC, Department of Pediatrics (Sickle Cell Program)
Background: Hydroxyurea is a frequently used medication in sickle cell disease. To date, no data is available regarding the impact of hydroxyurea (HU) therapy on osteonecrosis of the femoral head (ONFH), which is both a common and potentially debilitating complication of sickle cell disease. This study seeks to determine if longer duration use of hydroxyurea before the diagnosis of ONFH is associated with delayed progression and less frequent need for total hip arthroplasty (THA) compared to shorter duration therapy in patients with sickle cell disease.
Methods: All patients of the UNC Comprehensive Sickle Cell Program seen from 1990 to 2009, currently over age 12 and prescribed hydroxyurea were initially reviewed for inclusion in this descriptive retrospective study. Electronic medical records were reviewed for HU prescriptions, NSAID and narcotic prescriptions, surgical interventions, and baseline lab values before and after HU therapy. All available hip radiographs were staged by a radiologist blinded to the patient’s HU status. The primary outcome measures are the progression of radiographic stage of ONFH to collapse (Steinberg stage IV) and need for THA. Secondary analysis will include development of ONFH in a previously normal hip, need for surgical intervention other than THA, and number of NSAID/narcotic prescriptions in the past year of follow-up.
Results: This study is currently in progress and results are not yet available.
Conclusion: The results of this preliminary, descriptive study will benefit the hematology and orthopedic communities who care for patients with osteonecrosis and sickle cell disease. If HU therapy is found to correlate with slower progression of ONFH this data will add to the many known benefits of HU in SCD. Additionally, whether negative or positive, these findings will add a new perspective on the pathophysiology of osteonecrosis in this population.
Ramsey M. Wehbe
Risk of Total Joint Arthroplasty in Patients with C282Y-Homozygous Hemochromatosis
Ramsey M. Wehbe, MS1; Yu Ying Yau, RN: Robert A. Wesley, PhD; Charles D. Bolan, MD; Susan F. Leitman, MD
Department of Transfusion Medicine at the National Institutes of Health
The single greatest factor affecting quality of life in patients with C282Y-homozygous HFE-hemochromatosis (HH) is arthritis, which may be progressive even after achievement of iron depletion by phlebotomy therapy. We retrospectively analyzed the incidence of total joint arthroplasty (TJA) as a surrogate endpoint for severe, debilitating arthritis in 349 iron overload subjects according to HFE genotype. Subjects were divided by HFE genotype into a C282Y-homozygous study group and a concurrent control group of all other combinations of C282Y, H63D, S65C or WT alleles. TJA was defined as either total hip (THA), knee (TKA), or ankle (TAA) arthroplasty. Twenty-two of 244 C282Y-homozygous (8%) and 2 of 105 control non-C282Y-homozygous (2.2%) subjects underwent a total of 39 TJA’s (29 THA, 5 TKA, and 5 TAA). The age-adjusted risk of TJA was significantly greater in C282Y-homozygotes than non-homozygotes (log-rank p=.0214), with 31% of C282Y-homozygotes predicted to experience at least one TJA by age 74. The only factors significantly associated with an increased risk for TJA were ferritin and transferrin saturation values at the time of diagnosis; of these, only the initial ferritin remained significant in multivariate analysis. Our results suggest that C282Y-homozygous hemochromatosis patients are at increased risk for TJA, and this risk is further associated with the degree of iron overload at diagnosis. Furthermore, our data support the premise that once present, degenerative joint disease in HH is progressive and does not improve with phlebotomy therapy, as the ferritin level prior to initiation of phlebotomy was the strongest risk factor for TJA. These results provide a rationale for early genetic screening programs in populations at risk for the HFE C282Y mutation. Initiation of phlebotomy therapy before an elevated ferritin develops may prevent the morbidity and expense of TJA and also significantly contribute to the allogeneic blood supply.
PUBLIC HEALTH – Oral
Lauren M. Abbate
BMI and Waist Circumference and Incident Radiographic Knee Osteoarthritis in Women and Men: The Johnston County Osteoarthritis Project
Lauren M. Abbate, MSPH June Stevens MS, PhD, Charles Poole, ScD, Todd A. Schwartz DrPH, Leigh F. Callahan PhD, Jordan B. Renner MD, Charles G. Helmick MD, and Joanne M. Jordan MD, MPH
University of North Carolina
Background: BMI is a well-established risk factor for incident radiographic knee osteoarthritis (rKOA), however few studies have examined the association between waist circumference (WC) and rKOA. The purpose of this study was to determine the relationships between BMI and WC and incident rKOA in women and men. Methods: Data for this analysis were from 542 men and 931 women enrolled in the Johnston County Osteoarthritis Project, a longitudinal study of Black and White individuals aged 45 years and older in Johnston County, NC. BMI and WC were categorized using sex-specific thirds of the sample distribution. Hazard ratios and 95% confidence intervals [HR (95% CI)] were estimated for the associations between BMI and WC using sex-specific Weibull models with adjustment for age and race. Results: At baseline, the mean (SD) age, BMI, WC, and follow-up times for women were 55.5 (9.5) years, 28.8 (6.0) kg/m2, 90.8 (13.8) cm, and 6.1 (1.3) years; for men they were 59.0 (9.3) years, 28.4 (4.6) kg/m2, 101.2 (11.6) cm, and 5.7 (1.3) years. For both women and men ~15.0% of the knees developed rKOA. Among women, increasing thirds of WC were associated with increased hazards of rKOA (lowest third=referent; middle third=1.68 (1.10, 2.58); upper third=3.20 (2.13, 4.80)); similar associations were found for BMI. Among men, increasing thirds of WC were associated with increased hazards of rKOA (lowest third=referent; middle third=1.75 (1.08, 2.84); upper third=1.83 (1.13, 2.95)). For BMI, men in the middle [1.47 (0.93, 2.35)] and upper [1.41 (0.80, 2.23)] thirds had elevated but similar hazards. Conclusion: Among men, the relationship between BMI and rKOA appears to be different than the relationship between WC and rKOA, while among women these two relationships appear to be similar, suggesting that measurement of WC may be warranted, especially in men.
Screening Mammography Performance in Women 65 and Older
Jennifer Dickerson, Louise Henderson, PhD, Bonnie C. Yankaskas, PhD
UNC, Department of Radiology
Background. Much controversy exists over breast cancer screening among women >65 years.
Objective. To describe screening mammography performance measures (recall rates, sensitivity, specificity, predictive values, cancer detection rates (CDR)) and tumor characteristics for women >65.
Methods. We included 1996-2006 Carolina Mammography Registry data for women >65 with a screening visit and no history of Breast Cancer. At each visit, women provide demographic and history information and radiologists provide assessment and follow-up recommendations. Mammograms are linked with NC Central Cancer Registry and pathology data for cancer diagnosis within 12 months of the screening mammogram. Performance measures were calculated for 5-year age groups from 65 to 84 and >85. Tumor characteristics are described by age group.
Results. Among 103,275 women, we identified 305,647 screening mammograms. The distribution of mammograms by age group is 35.2% ages 65-69, 29.3% ages 70-74, 21.0% ages 75-79, 10.4% ages 80-84 and 4.1% ages >85. The CDR/1,000 mammograms by age group is 6.9, 7.4, 7.7, 8.0 and 6.9. There was little difference in the distribution of race, breast density, history of breast procedures, positive family history and subsequent screens across age groups. Current hormone therapy use decreased from 30.0% in women 65-69 to 9.4% in women >85. For all women >65, recall rate is 5.7%, sensitivity 78.4%, specificity 94.8%, PPV 10.0% and CDR 5.7/1,000 mammograms. Recall rate decreased with increasing age. All other performance measures increased with increasing age except among women >85. Overall, DCIS accounted for 17.8% of cancers. Among invasive cancers, 92.0% were ductal. Generally, early stage disease increased with age.. Among invasive cancers, 74.6% were moderately or well differentiated, 15.2% had positive nodes, 14.9% were >2.0cm, and 82.4% were ER+.
Conclusions. Performance measures and CDR increase until age 85. Tumor characteristics point to increasing detection of breast cancer with good prognostic characteristics until age 80.
Differences in the Quantity of Information Available to Emergency Department Providers During the Evaluation of Nursing Home Patients Based on Nursing Home Revenue Source
Fortune Egbulefu, Tim Platts-Mills, Brenda McCall
UNC, Emergency Department
Objectives: Lack of access to medical information for nursing home patients (pts) is a common problem for Emergency Department (ED) providers. We sought to determine if there was a difference in the availability of information based on financial resources of the nursing home. Methods: This was a 6 month prospective observational study of skilled nursing facility (SNF) pts > 65 years evaluated at a single academic ED. For each pt, ED physicians documented the availability of 11 information items: visit reason, history of present illness, medications, allergies, baseline mental and ambulatory status, primary provider name, family or healthcare power of attorney name, advanced directives, and if known whether cardiopulmonary resuscitation should be attempted. SNFs were categorized as either accepting Medicaid or being privately funded. T-test or Fisher’s exact test was used to compare SNF type. Results: Information on 142 subjects was available for analysis, including 109 (77%) pts from 1 of 15 SNFs that accept Medicaid and 33 pts from 1 of 4 privately funded SNFs. Privately funded SNF pts were older (87 vs 79, p<.001) and more often white (97% vs. 66%, p=.007) than pts from SNFs accepting Medicaid. Privately funded SNFs pts had a higher number of information items than Medicaid funded SNF pts (9.9 vs 8.2, p=.001). Differences in available information between privately funded and Medicaid funded SNF pts included history of present illness (94% vs. 75%, p=.03) and advanced directives (94% vs. 62%, p<.001). Medicaid funded compared to privately-funded SNF pts were more often missing >4 information items (30% vs. 6%, p=.005). Conclusions: More information is available to ED providers for privately funded than Medicaid funded SNFs pts. Further study is needed to explain this information gap and develop interventions to improve information exchange during transitions for all elderly individuals.
Rotavirus Vaccination: Need and Challenges in Tasba Pri, RAAN, Nicaragua
Meredith Gilliam, Sheri Denslow, Jess Edwards, Douglas Morgan
UNC Gastroenterology - Division of Digestive Diseases and Nutrition
Background: Diarrheal illness is common in Nicaragua, particularly in the North Atlantic Autonomous Region (RAAN), where water sanitation measures are scarce. Rotavirus is the leading diarrheal pathogen in children worldwide. Nicaragua implemented a program to vaccinate infants with Rotateq® rotavirus vaccine in 2006. Aims: We determined the prevalence of diarrheal illness in the Tasba Pri area of RAAN, the coverage rate of Rotateq® and other childhood vaccines in children under 4, and attitudes about and access to vaccines. Methods: Communities in Tasba Pri were sampled using a 30x7 frame. After the selection of 30 clusters, 7 households were randomly selected per cluster. Mothers aged 15-49 having children under 4 were interviewed about diarrhea, vaccines, and health care access. Data from Ministry of Health-issued vaccine cards were recorded. Results: 59% (111) mothers had children under 4. Of 189 households, 41% reported at least one incidence of diarrhea in the past month, lasting an average of 5 days. Of the 82% of children under 4 presenting vaccine cards, only 24% were up-to-date on all required vaccines. Approximately 34-42% of children received at least one dose of Rotateq® vaccine, while other required vaccines were distributed to 58-90% of children. While 98% of mothers considered childhood vaccinations to be “very important” or “important,” the top two reasons cited for why children missed vaccines were lack of supply at the nearest clinic (42%) and distance to the clinic (29%). Discussion: The rotavirus immunization rate in Tasba Pri infants is consistent with initial expectations, at approximately half of the national immunization rate (78%). The greatest reason for this discrepancy is lack of supply of the vaccine to local clinics, followed by the distance between households and the nearest clinics. Diarrheal illness is a major health problem in this region, and interventions should focus on improved rotavirus vaccine supply as well as general improvements to health infrastructure.
Drug Store Accessibility and Usability Project for Older Adults: Interdisciplinary Certificate in Aging, Fall 2008
Leak A, Byars G, Hoyle J, Coppola S, Ivey Burkhart J, Zimmerman S.
UNC, Schools of Public Health and Pharmacy
Background: Community pharmacies should be interested in changing their business practices to accommodate people over the age of 65, as the purchasing power of this demographic is projected to increase.
Methods: Through four monthly seminars, an interdisciplinary team of students developed recommendations to improve older adult accessibility and usability. After a case study, the team visited local drug stores, developed recommendations and priorities for improving the stores, and provided the feedback to pharmacy managers.
Results and Conclusions: Based on their site visits, independent research, and educational backgrounds, the team identified six areas of potential improvement: accessibility, mobility, visibility, organization/layout, store environment, and information/assistance. Within each of these six areas, the team developed specific recommendations. Finally, the team presented a written product of their findings and discussed the feasibility, cost, and priority of their recommendations. Rebecca Chater, director of clinical services at Kerr Drug, Inc has since laid plans with the IOA to host future seminars and to implement the current recommendations at a new store.
BASIC SCIENCE – Poster
Anatomic variation of the sigmoid colon in the pathogenesis of sigmoid volvulus in Lilongwe, Malawi
Adesola Akinkuotu, Jonathan C. Samuel, Nelson Msiska, Chimwemwe Mvula, Anthony G. Charles
UNC Hospitals Department of Surgery & Kamuzu Central Hospital, Lilongwe, Malawi
Introduction: Sigmoid volvulus (SV) is a surgical emergency. It accounts for 20-50% of all cases of bowel obstruction in sub-Saharan Africa. Though the anatomy has been implicated in its pathogenesis, no studies have examined this objectively. We sought to evaluate the role of anatomic variation of the sigmoid colon in pathogenesis of SV.
Methods: This was a prospective case-control study. Cases were individuals >18yrs with an intra-operative diagnosis of sigmoid volvulus. Controls were those undergoing laparotomy for reasons excluding pathology of the descending or sigmoid colon, or rectum. Intraoperative measurements of the sigmoid colon were taken. These measurements were compared between groups using Kruskal-Wallis equality of populations rank test.
Results: 17 subjects were enrolled in the study (10 cases and 7 controls). The sigmoid colon mesenteric length was longer in cases (median 27cm, range 15-33cm) than controls (median 12cm, range 6-15cm) (P=0.0008). The ratio of the mesenteric root width to mesenteric length was less in cases (median 0.26, range 0.17-0.40) than controls (median 0.5, range 0.41-1.5) (P=0.0006). The mesenteric root width itself did not differ between cases (median 6.25cm, range 4.5-10cm) and controls (median 7cm, range 6-11.5cm) (P=0.33).
Conclusion: The anatomy of the sigmoid colon in individuals with sigmoid volvulus is significantly different from those with non-pathological sigmoid colon. It is a long sigmoid mesentery that predisposes individuals to developing SV, rather than a narrow mesenteric root. This is the first prospective study that both provides strong evidence for an anatomic predisposition to SV, and elucidates these specific anatomic features.
Epithelial Cell Wounding by Interfacial Stress
Briana Buckner, Randolph W. Stroetz, Richard A. Oeckler, Deborah L. Rasmussan and Rolf Hubmayr
Department of Pulmonary and Critical Care Medicine, Mayo Clinic Rochester MN
Alveolar epithelial cells (AEC) that line the blood gas barrier in the lung are frequently exposed to lytic stresses as a result of mechanical ventilation. For example, the interfacial tension created by an advancing air/liquid interface in a small airspace may create a pressure gradient that deforms, and potentially wounds, the lining AEC. Since cell wounding is an important driver of inflammation, interventions, which protect AEC from deformation injury and/or promote plasma membrane wound repair, could be of therapeutic benefit. Previous studies in our laboratory suggest that conditioning of lungs and lung cells with hypertonic media may be such an intervention.
The goal of this experiment is to develop a microfluidic model system to test the effects of medium tonicity on epithelial injury. The microfluidic model system contains two parallel slides divided by a separator wall of 1.7mm in height contained in a metal chamber. Through silicone tubing the air bubble is administered through one end of the chamber.
Human immortalized AECs (A549) were grown until confluent on 12cm2 glass slides, placed in a custom fabricated microfluidics chamber and perfused with a propidium iodide (PI) containing saline solution. Propidium iodide (PI) is used to differentiate normal cells from wounded cells. PI is impermeable to the cell membrane and becomes intercalated to the DNA or RNA of the cell once there has been injury to the cell membrane. The cells were then imaged utilizing a fluorescence microscope to quantify baseline PI fluorescence, a marker of cellular injury. An air bubble was then passed through the chamber at a fixed flow rate of 5.91ml/min comparable to the air flow through a re-opening collapsed airway. The cells were then re-imaged and the post-intervention PI fluorescence was expressed as percent of baseline injury.
The results show that the model does induce stress on the cells which results in injury of the cell membrane. The model system produces an average of 17 percent cell damage. In conclusion we have demonstrated that the interfacial forces that are generated in our model system are sufficient to damage epithelial cells, and are now in a position to test mechanistic hypotheses about the determinants of cell injury and the effects of interventions on them.
Pneumolysin Induces Activation of the NLRP3-Inflammasome
Ejiofor Ezekwe, Joseph Duncan
UNC Department of Medicine - Division of Infectious Disease
Streptococcus pneumoniae is a leading cause of multiple diseases including community-acquired pneumonia and meningitis. It is also a leading cause of infection related death in both the young and old (1). A critical factor related to the virulence of S. pneumoniae is pneumolysin. Pneumolysin is a cholesterol dependent pore-forming toxin that leads to lung damage and inflammation (3). Pneumolysin is known to mediate both cell death and activation of the inflammatory signaling protease, caspase-1 (2, 4). Our lab has recently shown that alpha-hemolysin, a critical virulence factor in Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA), which like pneumolysin is a pore-forming bacterial toxin, is a potent stimulators of a complex referred to as the NLRP3-inflammasome. The NLRP3-inflammasome is responsible for activation of caspase-1, which ultimately leads to the secretion of multiple pro-inflammatory cytokines such as IL-1beta and IL-18. The NLRP3 inflammasome also induces programmed necrotic cell death. In this study we sought to determine whether pneumolysin could also be a potential stimulator of the NLRP3-inflammasome. Using monocyte like cell lines that had both normally functioning inflammasome components as well as knockdown cell lines that lack expression of NLRP3 or other inflammasome components, we set out to probe this issue. In response to pneumolysin, control cell lines produced much greater levels of IL-1beta and also had increased cell death when compared to NLRP3-inflammasome knockdown cell lines. These findings suggest the NLRP3-inflammasome might be an important host factor in determining pneumolysin-mediated virulence of S. pneumoniae.
1. Lynch, J. P., 3rd, and G. G. Zhanel. 2009. Streptococcus pneumoniae: epidemiology, risk factors, and strategies for prevention. Semin Respir Crit Care Med 30:189-209.
2. Marriott, H. M., and D. H. Dockrell. 2006. Streptococcus pneumoniae: the role of apoptosis in host defense and pathogenesis. Int J Biochem Cell Biol 38:1848-54.
3. Marriott, H. M., T. J. Mitchell, and D. H. Dockrell. 2008. Pneumolysin: a double-edged sword during the host-pathogen interaction. Curr Mol Med 8:497-509.
4. Shoma, S., K. Tsuchiya, I. Kawamura, T. Nomura, H. Hara, R. Uchiyama, S. Daim, and M. Mitsuyama. 2008. Critical involvement of pneumolysin in production of interleukin-1alpha and caspase-1-dependent cytokines in infection with Streptococcus pneumoniae in vitro: a novel function of pneumolysin in caspase-1 activation. Infect Immun 76:1547-57.
Effects of Nitric Oxide-Delivering Sponge on Achilles' Tendon Healing
Jeffrey Spang, Lindsay Foley
UNC, Department of Orthopedics
Rotator cuff repair is a common orthopaedic procedure that requires tendon to bone healing. Multiple, large studies have reported a relatively high rate (up to 20 percent) of repair failure due to poor tendon healing. Prior basic science research has revealed that Nitric Oxide (NO) may have positive effects on tendon healing, noting increased tendon strength in a healing model using locally applied NO. We investigated the use of NO released from a locally implanted collagen sponge to stimulate tendon healing in a rat Achilles tendon injury model. Four groups of Sprague-Dawley rats had an index surgery consisting of complete Achilles tendon transection. Group 1 was a control while Group 2 had a blank collagen sponge implanted. Group 3 had an implantable sponge with a low concentration of NO (20 mM) while Group 4 had an implantable sponge loaded with a high concentration of NO (60 mM). Fourteen days after the index surgery, the rats were sacrificed. Biomechanical testing was carried out using an MTS servohydralic testing machine (load to failure, stress under loading, and maximum displacement at failure). Additionally, we measured tendon repair cross sectional area, length of the total tendon after repair, and histologic quantification of the repair collagen. Statistical analysis was carried out using the One Way Analysis of Variance to account for multiple groups. There were no significant differences in any of the measured outcomes. For each biomechanical measures, there were no differences observed between groups. The same is true with regards to collagen organization or collagen content. Our results fail to show that NO delivered through locally placed collagen sponges has an effect on healing properties in a rat Achilles tendon model.
Tilden Hagan, Briana Carstens, Adam Shields, Richard Superfine
University of North Carolina
PDMS (polydimethylsiloxane) microposts are being developed for use as a cellular substrate on which the mechanical forces of cellular movements can be measured. Posts are thin, tall, flexible structures made from a silicone elastomer PDMS (polydimethylsiloxane). An array of posts can be formed such that their tips create a flat surface on which cells can adhere. Current substrates are continuous solids which have certain limitations. A solid substrate is more difficult to analyze and compute forces due to the need to integrate all forces at any point on the substrate. A micropost allows a discreet location of interaction where a force will deflect the post. This deflection can be easily measured to then calculate the applied force. We created a mask to determine the ideal diameter and spacing of posts such that they are strong enough to not easily fall over, and spaced far enough apart to prevent them from collapsing onto each other. We found that at a height of approximately 10 micrometers the ideal diameter was 1.5 micrometers with a 5 micrometer spacing between centers.
The Dynamic Role of Thrombospondin-1 and Osteopontin on the Enhanced Proliferation of Vascular Smooth Muscle Cells in Hyperglycemic Conditions
Christopher Hanzaker, Lee B. Allen, Katherine Gollahon, David R Clemmons, Laura A Maile
UNC, Department of Medical Endocrinology
In this study we aimed to show the dynamic role the αvB3 integrins, osteopontin and thrombospondin-1 (TS-1), play in the stabilization of integrin associated protein (IAP) and how their expression is altered in high versus low glucose conditions. When SMC are maintained in hyperglycemic conditions they are more responsive to IGF-I than those in normo-glycemic conditions. The increase in IGF-I responsiveness is attributable to a hyperglycemia induced increase in intact integrin associated protein IAP or CD47 and thus an increase in its association with SHPS-16 which is required for SMC to respond to IGF-I.
TS-1 is a ligand for CD47/IAP 37 and enhances IGF-I signaling in SMC. Our previous studies determined that there was a significant increase in the amount of TS-1 associated with the ECM surrounding SMC grown in 25 mM glucose compared with those grown in 5 mM glucose.
In this study we determined that the increase in TS-1 plays an important role on the hyperglycemia induced increase in IGF-I responsiveness. Addition of a peptide homologous to the CD47/IAP binding site of TS-1 to SMC in normo-glycemic conditions was sufficient to enhance IGF-I responsiveness. Similarly, reducing TS-1 protein levels using RNA interference in SMC maintained in hyperglycemic conditions was sufficient to inhibit IGF-I signaling. Our studies also revealed that the difference in the amount of TS-1 in the two different glucose conditions was due, at least in part, to a difference in TS-1 degradation since the level of TS-1 in normo-glycemic conditions could be restored to that of hyperglycemia in the presence of two different types of lysosomal enzyme inhibitors. Interestingly while TS-1 levels were shown to be regulated by protein degradation, osteopontin (OPN) RNA increased almost 2 fold in SMC grown in high glucose compared to low glucose. While a probable CD47/IAP binding site on OPN was identified, in vivo studies did not definitively show that OPN stabilizes IAP/CD47.
An Evaluation of Carrier Agents for Desferoxamine, an Up-Regulator of Vascular Endothelial Growth Factor
Hertzberg, B P; Holt, J B; Graff, R D; Gilbert, S R; Dahners, L E
UNC, Department of Orthopaedics
Avascularity and hypoxia result in avascular necrosis and play a negative role in fracture healing. The FDA approved iron chelating agent, desferoxamine (DFO) has been shown to induce angiogenesis and improve fracture healing through upregulation of vascular endothelial growth factor (VEGF). We were concerned that local injection of DFO in a liquid form would either fail to adequately deliver sufficient drug to the desired site, or lead to undesired delivery to adjacent sites. Therefore, a sustained release delivery system was desirable to direct DFO to the intended site. Calcium sulfate pellets, collagen sponges, and demineralized cortical bone matrix were all evaluated as potential controlled release systems for desferoxamine using a fetal mouse metatarsal angiogenesis assay. Angiogenesis was analyzed using a vascularity grading scale, by measuring the mean vessel length of the 5 longest vessels, and by counting the mean number of vessels per metatarsal. Although there was some evidence of angiogenesis with all three carriers, DFO loaded CaSO4 pellets increased vascularity grading, the mean length of the 5 longest vessels, and the mean number of vessels, all by statistically significant margins versus the control. These results suggest that CaSO4 pellets could be used as a viable, nontoxic, controlled release system for desferoxamine in clinical situations where increased angiogenesis and bone growth are desirable.
Mechanisms of Transcriptional Deregulation in Ewing's Sarcoma
Michael Iglesia, Mukund Patel, Jeremy Simon, Andrew McFadden, Ian Davis
UNC Lineberger Comprehensive Cancer Center
Ewing’s sarcoma is a rare bone and soft tissue cancer primarily affecting patients between the ages of 15 and 20. It is characterized by a reciprocal chromosomal translocation, which in 85% of patients involves chromosomes 11 and 22 and fuses the genes EWS and Fli1. The transcribed protein, EWS-FLI1, contains the EWS activation domain of EWS and the Ets family DNA-binding domain of FLI1. EWS-FLI1 acts as an aberrant transcription factor, driving the Ewing’s phenotype. The overall goal of this work is to investigate why EWS-FLI1 and FLI1 bind the different regions of DNA they do throughout the genome, and what effect this difference in binding has on gene regulation. In this work, EWS-FLI1 and FLI1 are compared using a primary Ewing’s tumor cell line in which the endogenous EWS-FLI1 is knocked down and subsequently rescued with near-endogenous levels of tagged EWS-FLI1 or FLI1 using lentivirus. To investigate the effect of differential binding on gene expression in these settings, genome-wide DNA binding data (from ChIP-seq) are combined with gene expression data for both the EWS-FLI1 and FLI1 settings. Binding of EWS-FLI1 and FLI1 to GGAA microsatellites, regions previously identified as being important in binding EWS-FLI1 to up-regulate genes, is investigated through quantification of microsatellite sequences in binding regions. Additionally, known motif detection algorithms are used to identify cooperating transcription factors important in mediating the Ewing’s phenotype. EWS-FLI1 is shown to bind GGAA microsatellites to up-regulate nearby genes, while FLI1 does not significantly bind these regions. Finally, several DNA binding motifs, most notably the STAT motif, are identified as potential cooperating factors for EWS-FLI1.
Identification of Mutations in the Zinc Transporter Gene SLC39A13 in Ehlers-Danlos Syndrome Type VIB (EDS VIB)
Elizabeth Ju, Linda Walker, Heather Yeowell
Duke Medical Center- Dermatology Department
Collagen is the most abundant protein in connective tissue, and also the most copious protein in mammals. Problems with collagen biosynthesis, ultimately affecting connective tissue, can lead to fatal diseases that express a variety of clinical phenotypes. The Ehlers-Danlos syndrome (EDS) is a group of heritable connective tissue disorders that are clinically characterized by fragile and hyperextensible skin, and joint hypermobility. A recent study reports that six patients from two consanguineous families had phenotypes similar to those of EDS type VI, but also presented with skeletal dysplasia, short stature and osteopenia. Fibroblasts from these patients have reduced hydroxylysine content, suggesting LH deficiency. Cultured fibroblasts from the same patients were tested for their lysyl and prolyl 4-hydroxylase activities, and were found to be of normal levels. EDS VIB patients that have normal LH activity may also contain mutations in the SLC39A13 gene. We screened EDS VIB patients for possible mutations in the Zn2+ transporter, hoping to shed some light on the pathophysiology that leads to the clinical phenotypes seen in EDS VIB patients. Methods to uncover possible mutations included isolation of genomic DNA, gel electrophoresis of PCR products, and mutational analysis by sequencing. Screening of exon 2, 3, 4, 6, 7, 8, 9, and 10 revealed no mutations, although polymorphisms were identified. It is possible other mutations in the SLC39A13 gene are contained in the introns or in exon 1 of the gene, which were not screened in our study, and is the cause of the protein defect in the Zinc transporter. Identification of mutations in the SLC- gene will broaden the understanding of the pathophysiology of diseases related to connective tissue disorders.
Developing RGS Proteins as a Therapeutic Target
Klara R. Klein, Tom Zielinski, Adam J. Kimple, Mark D. Koeff, Robert G. Lowery, David P. Siderovski, and Stephanie Q. Hutsell
UNC, Department of Pharmacology
The G protein-coupled receptor (GPCR) superfamily has provided many valuable targets for drug discovery across a variety of clinical needs and diseases. Over ten years ago, the Siderovski lab and other groups independently discovered a large family of negative regulators of GPCR signal transduction, the “RGS proteins”, but their potential as drug discovery targets has yet to be tested owing to the present dearth of inhibitors or activators for this protein family. RGS proteins inhibit GPCR signaling by accelerating the intrinsic GTP hydrolysis rate of the Galpha subunit that is coupled to the receptor. Development of chemical probes and, ultimately, drugs that act at the level of the RGS protein and its Galpha•GTP substrate could improve therapy for multiple pathological conditions, such as hypertension, schizophrenia, and Parkinson’s disease, that are either caused or exacerbated by aberrant GPCR signaling. We recently developed an enzymatic assay for high-throughput screening of small molecule libraries for modulators of RGS protein action; this assay combines a mutant Galpha substrate (possessing enhanced spontaneous GDP release) with a fluorescence polarization immunoassay for GDP production. One of the actives identified in a pilot screen of the GenPlus library of 960 compounds, ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), was found to inhibit RGS4-accelerated GTPase activity by Galphai1. Ebselen also had inhibitory activity in a secondary, FRET-based assay that directly measures RGS domain binding to Galphai1. However, treatment of ebselen with reducing reagent (ie., DTT) quenched inhibitory activity, suggesting that ebselen may be reactive towards either the RGS protein or Galphai1. Our long-term goal is that, by high throughput screening, we can identify active (not reactive) RGS modulatory compounds for development into novel chemical probes and drugs that act at the level of the RGS protein to improve therapy of multiple diseases caused or affected by aberrant GPCR signal transduction.
Role of Neurogenin 2 in axon guidance during cortical development
Katharine Liang, Randal Hand, and Franck Polleux
UNC Neuroscience Center
Neurogenin2 is a proneural basic helix loop helix transcription factor expressed in cortical progenitors that give rise to glutamatergic pyramidal neurons. Pyramidal neurons have several defining characteristics including using glutamate as an excitatory neurotransmitter, undergoing radial migration, having a large unipolar dendrite and a long projecting axon. In addition to regulating neuronal differentiation, Ngn2 has previously been shown to regulate neurotransmitter expression, neuronal migration, and dendritic morphology during cortical development. Since Ngn2 regulates many aspects of pyramidal neuron differentiation, we hypothesized that Neurogenin2 also regulates the axonal projections of pyramidal neurons. To test this hypothesis, we employ an electroporation technique to investigate the role of Neurogenin2 in axon guidance. The ex vivo electroporatation technique allows for the genetic manipulation of specific neuronal progenitors. Progenitors electroporated at E15.5 give rise to superficial neurons (Layers II&III) that project medially, as opposed to deeper layers (Layers V&VI) that project laterally. Neurogenin knock-down resulted in axonal misprojections in superficial neurons that were visualized by confocal microscopy and quantified using the ImageJ Plugin AxonQuant. Electroporated neurons were confirmed to be of layer II&III identity using immunohistochemistry, suggesting that the axonal projection abnormalities were due to an axon guidance defect, rather than one of cell fate determination. Further studies will identify potential transcriptional targets responsible for these misprojection defects.
Umbilical cord derived mesenchymal stem cells demonstrate robust osteoinduction and may be an ideal source for tissue-engineered bone
Gitanjali Madan, BA MS, Montserrat Caballero, PhD, John A. van Aalst, MD
UNC Chapel Hill, Department of Surgery, Division of Plastic Surgery
Introduction: Adult abdominoplasty (AA) fat is an increasingly utilized source for mesenchymal stem cell (MSC) harvest, and may be considered a gold standard for clinical tissue regeneration: it is routinely discarded after surgery, abundant, easy to harvest, and has been demonstrated by multiple researchers to generate mesodermal tissue, including bone. Children however, do not have the same abundant quantities of fat as adults, nor are they likely to undergo a procedure during which fat is routinely discarded. For children with craniofacial bone defects, finding an alternate source for MSCs is a reasonable strategy. Two such sources of MSCs are the palate periosteum (PP) and the umbilical cord (UC). PP is a post-natal source of MSCs that has not been evaluated extensively. In children with cleft palate, PP is easily accessible, may be harvested at the time of palate repair, and poses minimal risk to the patient. Alternatively, the UC is an emerging, yet significantly under-utilized source of MSCs. The UC, like AA, is a discarded tissue, theoretically with an unlimited supply, which can be harvested in children with craniofacial bone abnormalities at birth, well in advance of reconstructive procedures for bone defects.
Objective: To characterize MSCs from three sources: Adult Abdominoplasty (AA), Palate Periosteum (PP), and Umbilical Cord (UC) by surface marker prevalence, and by osteoinductive capability.
Methods: IRB approval was obtained for harvest of AA, PP, and UC. The presence of MSCs was determined using immunostaining and flow cytometry for cell surfaces markers specific for mesenchymal cells, including CD 73, CD 90, CD 105 and SSEA-4. Osteogenesis was induced using media containing dexamethasone, b-glycerophosphate, and ascorbic acid. Osteoinduction was evaluated qualitatively using Alizarin Red S staining, and quantitatively using real-time fluorescent quantitative PCR (RT-PCR) with an ABI PRISM 7700 (Applied Biosystems). Analysis was performed using ribosomal 18S RNA as an internal standard and the 2−ΔΔCT quantification method. Osteogenic markers evaluated included bone morphogenetic protein-2 (BMP-2), Alkaline Phosphatase (ALP), and Osteocalcin (OST) at days 7, 14, and 21.
Results: MSCs from AA, PP, and UC all stained positive for the mesenchymal specific cell markers CD 73, 90, 105 and SSEA-4, although the three populations of cells had varying distributions in cell-surface marker expression. Following osteoinduction, MSCs from all sources stained positive for calcium deposition using Alizarin Red staining. RT-PCR for BMP-2 mRNA showed a 3.2-fold increase in AA, a 53.8-fold increase in PP, and a 685-fold increase in UC MSCs by day 21 of culture. Additionally, RT-PCR for ALP mRNA showed a 1.3-fold increase in AA, a 5.2-fold increase in PP, and a 49.9-fold increase in UC MSCs by day 21 of culture. OST mRNA was approximately equivalent.
Conclusions: Following osteoinduction, umbilical cord MSCs showed a significantly more robust increase in mRNA for BMP-2 and ALP than MSCs from either palate periosteum or adult abdominoplasty fat. Given these findings, the umbilical cord may be the ideal source of MSCs for tissue engineered bone in children.
The discovery of a heterotrimeric G-protein and its putative regulator in Entamoeba histolytica
Robin Muller, Adam Kimple, Francis Willard PhD, David Siderovski PhD
Department of Pharmacology, UNC
The intestinal parasite Entamoeba histolytica infects over 40 million people a year and kills 100,000 people annually. Its invasive behavior is mediated by small G-protein signal transduction, but the initiator of this signaling is unknown. We identified components of a novel signaling pathway within E. histolytica, including a set of heterotrimeric G-protein subunits: one canonical Gα subunit (EhGPA1), one Gβ subunit (EhGB1), and two Gγ subunits (EhGG1 and EhGG2). An additional component of heterotrimeric G-protein signaling in the E. histolytica genome was identified, regulator of G-protein signaling-1 (EhRGS1). This protein is predicted to encode an RGS-box domain known to accelerate the intrinsic GTP hydrolysis activity of Ga subunits. Additionally, EhRGS1 is predicted to encode guanine nucleotide exchange factor (RhoGEF) activity specific to small G-proteins of the Rho subfamily. This paper describes methods for the purification and in vitro functional analysis of EhGPA1, EhRGS1, including the development of constitutively active and dominant negative mutants of EhGPA1, a loss-of-function mutant of EhRGS1 and the isolation of its RhoGEF domain for biochemical characterization.
Restoration of B-cell Tolerance in Lupus Prone 2-12H/MRL/lpr Mice
Patrick Taus, Sang-Ryul Lee, Jennifer Ann Rutan, and Barbara Vilen
University of North Carolina
The effectiveness of the innate immune system is in large part due to its simplicity, but with this simplicity comes an inherent danger due to the existence of a population of potentially autoreactive B-cells. In healthy individuals this danger doesn’t come to fruition as B-cells that recognize self antigens are kept tolerant upon the binding of their toll-like receptors, while naïve B-cells are simultaneously allowed to differentiate into plasma cells. Previous studies have shown that this differential regulation is caused by the cytokines interleukin-6 (IL-6), soluble CD40 ligand (sCD40L), and Tumor Necrosis Factor alpha (TNF-alpha). However, in the disease state the same cytokines fail to repress antibody secretion in antigen experienced B-cells from lupus prone 2-12H/MRL/lpr mice.
Interestingly, it was also found that the basal phosphorylation levels of ERK, a MAP kinase, are significantly lower in B-cells from naïve C57BL/6, and 2-12H/MRL/lpr mice than those from antigen-experienced 2-12H/Vκ8 mice. Could the differences in basal phosphor-ERK levels explain the lack of IL-6, sCD40L, and TNF-alpha regulated tolerance in lupus-prone B-cells? In order to further investigate this question, B-cells from lupus prone 2-12H/MRL/lpr mice were retrovirally transfected with constitutively active MEK1, a MAP kinase kinase. ELISPOT data revealed that the presence of CA-MEK1 restored the ability of one of the cytokines, sCD40L, to regulated auto-reactive B-cells from 2-12H/MRL/lpr mice upon LPS stimulation. This result suggests the restoration of basal phosphorylated ERK levels could potentially serve as a therapy for Systemic Lupus Erythematosus.
Pulmonary delivery of siRNA for rhinovirus protection
Bennett Shum, Perry Tsai, Judy Lieberman
Immune Disease Institute, Harvard Medical School
SiRNAs cause degradation of their target mRNAs, thus shutting down translation of the corresponding protein. This powerful downregulation is potentially useful to prevent or cure infection in a number of diseases. Specifically, infectious lung diseases are attractive targets of siRNA-mediated therapy due to the accessibility of the lung to therapeutic agents through the nose and mouth, and the lethality and prevalence of diseases. One of the most frequent infectious agents is human rhinovirus, the causative agent of the common cold which infects via human ICAM-1. Through RT-PCR, we have demonstrated preventative and therapeutic properties of siRNAs directed against rhinovirus VP3 and POL and human ICAM-1, in HeLa cells infected with rhinovirus type 14 (major serotype). Through confocal microscopy, we have also demonstrated delivery of Cy3-labeled siRNAs into murine lungs via intratracheal delivery. While further experiments are necessary to demonstrate silencing and viral protection in vivo, these preliminary results are encouraging for siRNA therapeutics against infectious lung disease.
Inhibition of PC-3 Cancer Cell Migration and Invasion by 4-Phenyl-3-Butenoic Acid
Hannah Yin, Jeffrey Sunman, Steven Akiyama
National Institute of Environmental Health Sciences - Cell Adhesion Group, Laboratory of Molecular Carcinogenesis
Tumor cell metastasis is a multi-step process requiring migration of cells out of the primary tumor, invasion into the vascular or lymph system, adhesion to and invasion out of vessels, and ultimately migration into new tissue. Previous research has shown that stimulation of the gastrin releasing peptide (GRP) receptor is one pathway that can mediate the migration and invasion of prostate cancer cells. The major ligands for this receptor require C-terminal alpha-amidation to become biologically active. These active peptides then stimulate GRP-receptor in an autocrine fashion to promote the phosphorylation of focal adhesion kinase (FAK), a protein which plays a key role in cell migration and invasion. 4-Phenyl-3-butenoic acid (PBA) is an irreversible inhibitor of peptidylglycine alpha-monooxygenase (PAM), the rate-limiting enzyme in the alpha-amidation pathway. However, it has not been previously demonstrated whether PAM is a viable target for inhibiting cancer cell migration and invasion. In this study, we tested the hypothesis that inhibition of PAM by PBA will inhibit PC-3 prostate cancer cell migration and invasion through the inhibition of FAK phosphorylation.
Following pre-treatment with PBA, migration of PC-3 cells on collagen type IV substrates was inhibited in a time- and concentration-dependent manner, as quantitated by an in vitro assay designed to mimic cell migration out of a high density tumor. Furthermore, in another in vitro assay, treatment with PBA also inhibited the ability of PC-3 cells to invade through reconstituted basement membrane. In control experiments, the PBA treatment protocol used in these studies had no significant effect on cell viability or proliferation. Immunoblot analysis with an anti-phospho-tyrosine antibody demonstrated that treatment with PBA decreases phosphorylation of FAK in PC-3 cells adhering to collagen IV. In summary, these data suggest that inhibition of alpha-amidation with PBA can inhibit PC-3 cell migration and invasion through inhibition of FAK phosphorylation.
CLINICAL SCIENCE – Poster
James R. Bateman III
A Qualitative Analysis of Memory Test Data That May Help Predict Alzheimer’s Disease
James R. Bateman, Daniel I. Kaufer
UNC, Department of Neurology
Mild cognitive impairment (MCI) is a controversial transitional state between normal aging and Alzheimer’s disease characterized by isolated memory deficits. There is a 50% chance of progressing from MCI to Alzheimer’s disease over 5 years, but no reliable clinical predictor has been identified. The Hopkins Verbal Learning Task (HVLT) is a useful clinical measure of verbal episodic memory that allows for analysis of multiple component process variables. The HVLT contains 12 words from three semantic categories that are presented over three learning trials, followed by 20 minute delayed spontaneous recall and recognition recall, with the latter including the 12 original (target) words intermixed with 12 novel (foil) words. Among the 12 foils, half are semantically related to target words and half are not. Budson et al. (2003) demonstrated that patients with Alzheimer’s disease show a disproportionate number of false positive responses on semantically unrelated foils when compared to normal age-matched controls. However, this study did include not MCI patients or other dementia subtypes. We hypothesized that AD subjects would make more errors than MCI subjects on semantically unrelated foils, while there would be no difference on related foils. Data on 30 dementia subjects (13 AD, 8 MCI, 9 non-AD dementia) was utilized for analysis in this summer pilot project. Separate ANOVA were performed on related or unrelated foil errors with diagnosis as the grouping variable. The analysis for semantically unrelated foils showed a borderline significant difference [F(2,27) = 3.159, p = 0.06], whereas there was no difference between diagnostic groups for semantically related foils [F(2,27) = 0.091, p = 0.91]. Pairwise post-hoc comparisons between groups on the unrelated foil data showed a significant difference between AD and MCI subjects in the predicted direction (Fisher’s PLSD p < 0.04). These preliminary data support the study hypothesis and provide a foundation for a grant currently under review that will hopefully extend this work into a more robust study.
Alexander A. Berger
An Increase in Pelvic Bone Width Associated with Aging
Alexander A. Berger, Ryan May, Jordan Renner, Laurence E. Dahners
Department of Orthopaedics, UNC School of Medicine
Following an increase in length and width during childhood and adolescence, skeletal growth is assumed to stop during adulthood. In a previous study we observed that the width of the pelvis increased with age. In this study we more carefully investigated the influence of aging on the dimensions of the pelvis and L4 lumbar vertebra. The participants were 246 patients without significant bone abnormalities or orthopedic implants who received pelvic and abdominal CT-scans from the UNC Health Care System. The distances between the outermost edges of greater trochanters and iliac wings and the innermost edges of the pelvic inlet and inter-femoral head distances were measured. The height and width of the L4 vertebra was measured along with the diameter of the femoral head. Linear regression analysis was performed to examine the significance of relationships between age and width of the pelvis. There was a strong correlation between increasing patient age and increasing trochanteric width (0.0333 cm/year of age, p<0.0001) and increasing iliac wing width (0.0371 cm/year of age, p<0.0001). Furthermore there was a strong correlation between increasing patient age and increasing interfemoral head distance (0.0114 cm/year of age, p=0.0015), femoral head diameter (0.0055 cm/year of age, p=0.0005) and L4 width (0.0062 cm/year of age, p=0.0003). These correlations were seen across genders. Our results suggest that pelvic and vertebral dimensions enlarge in width after skeletal maturity and the cessation of longitudinal growth.
Elizabeth Hollin Calloway
3-Dimensional Computed Tomography (3-D CT) for Evaluation and Management of Children with Complex Chest Wall Anomalies: Useful Information or Just Pretty Pictures?
Calloway, E. Hollin, B.A.; Chhotani, Ali N., BS; Lee, Yueh Z., MD, PhD; Phillips, J. Duncan, MD
UNC -Chapel Hill, Department of Pediatric Surgery
Purpose: Shaded Surface Display (SSD) technology, with 3-D CT reconstruction, has been reported in a few small series of patients with congenital or acquired chest wall deformities. SSD images are visually attractive and educational, but many institutions are hesitant to utilize these secondary to cost and image data storage concerns. This study was designed to assess value of SSD in the evaluation and management of children with complex chest wall anomalies.
Methods: Following IRB approval, we performed a retrospective review of records of 82 patients with chest wall deformities, evaluated with SSD, from 2002 to 2009. SSD usefulness, when compared with routine 2-D CT, was graded on a strict numerical scale from 0 (added no value besides education) to 3 (critical for surgical planning and patient management).
Results: There were 56 males and 26 females. Median age was 15.3 years (range: 0.6-41.1). Deformities included 56 pectus excavatum, 19 pectus carinatum, and 8 other/mixed deformities. 6 patients also had acquired asphyxiating thoracic dystrophy (AATD), and 11 (13%) had previous chest wall reconstructive surgery. In 25 (30%) patients, SSD was useful or critical. Findings underappreciated on 2-D images included: sternal abnormalities (29), rib abnormalities (28), and heterotopic calcifications (7). SSD changed or influenced operation choice (4), clarified bone versus soft tissue (3), helped clarify AATD (3), and aided in rib graft evaluation (3). Point biserial correlation coefficient analysis displayed significance for SSD usefulness in patients with previous chest repair surgery (Rpb=0.48, p≤0.001), AATD (Rpb=0.34, p=0.001), pectus carinatum (Rpb=0.27, p=0.008), and females (Rpb=0.19, p=0.044).
Conclusions: Shaded Surface Display, when used to evaluate children and young adults with congenital or acquired chest wall deformities, provides useful or critical information for surgical planning and patient management in 1/3 of patients, especially those requiring a second operation, with acquired asphyxiating thoracic dystrophy, pectus carinatum, and females.
Matching Algorithms with Arabic Names
Beth Israel Deaconess, Division of Clinical Informatics - Boston, MA
Electronic medical records rely heavily upon name matching to identify individuals amongst large data sets. Master Patient Index software relies upon advance matching algorithms in order to resolve inconsistencies and match patients with their medical records. However, Arabic names have complexities that are not addressed in current matching algorithms. This poster will contain the market analysis of available software that addresses this problem.
Predicting Urine Culture Results in Afebrile Patients with Acute Renal Stone Disease
David C. Johnson, Angie B. Smith, Raj S. Pruthi, Culley C. Carson, Mathew E. Nielsen, Eric M. Wallen
Background and Objective: Patients with acute renal stone disease experiencing fever and unrelenting pain should undergo stent placement. It is less clear whether to offer medical management or place a stent in afebrile patients. We investigated laboratory results of afebrile patients with acute stone disease receiving stents to determine their utility in predicting a positive urine culture, thereby directing the decision to offer a trial of medical management. To our knowledge, no studies have examined laboratory cutoff points for stenting afebrile patients with acute stone disease.
Methods: Retrospective chart review of 645 patients was performed on afebrile patients with stone disease who underwent stent placement at UNC between January 2005 and January 2009. WBC and absolute neutrophil count (ANC) were recorded when available within 14 days before stent placement. Patients with missing WBC (n=241), ANC (n=392) or urine cultures (n=227) were excluded from the analysis. Receiver operating characteristic (ROC) analyses were performed using STATA v10.0. (College St, TX).
Results: 414 patients had documented urine culture results. A WBC count cutoff point of 15x109/L correctly classified 78.4% of cultures (sensitivity=23.4%, specificity=88.1%), and a cutoff of 19x109/L correctly classified 84.1% (sensitivity=12.8%, specificity=96.6%). An ANC cutoff point of 15x109/L correctly classified 80.1% (sensitivity=27.6%, specificity=89.2%) and a cutoff point of 19x109/L correctly classified 84.7% (sensitivity=10.3%, specificity=97.6%). Area of the ROC curve for WBC count and ANC was 0.61 and 0.68, respectively.
Conclusions: WBC count and ANC can be used to predict infection in afebrile patients with acute stone disease despite a poor diagnostic accuracy classification based on the ROC curves. High WBC count and ANC cutoffs (15x109/L or 19x109/L) predict a high percentage of positive cultures, and help identify patients that should not be offered medical management. Plans for a prospective study evaluating how other factors affect the accuracy of these tests are ongoing.
Application of Clinical Arterial Spin Labeling Cerebral Perfusion Imaging
Tyler B. Jones, Yueh Lee MD PhD, J. Keith Smith MD PhD
UNC, Department of Radiology
Millions of people are effected by chronic kidney disorder (CKD), a disease commonly comorbid with stroke and silent brain infarction (SBI). Renal insufficiency has also been indicated in nephrogenic systemic fibrosis (NSF), a severe disorder of connective tissue associated with the magnetic resonance (MR) imaging contrast agent gadolinium, which is frequently used for perfusion measures. Other populations, such as intensive care and pediatric patients, have contraindications for contrast enhanced MR imaging in addition to radiation based imaging techniques such as Positron Emissions Tomography (PET) and Computed Tomography (CT), all common modalities for quantifying cerebral perfusion. Thus, a problem exists in these patient populations when a need arises for cerebral perfusion measures due to comorbid vascular insults to the central nervous system. An alternative method is arterial spin labeling (ASL), an MR techniques that uses endogenous protons as tracers, eliminating the need for gadolinium. Though easily amenable to existing clinical MR imaging protocols, a major limitation to routine clinical application of ASL is the requirement of extensive data-processing and skilled analysts. To alleviate this limitation, we adapted our multimodal imaging software developed in conjunction with the UNC Department of Computer Science (Dr. Russell Taylor and David Feng), nDive (n-Dimensional Volume Evaluator), to simplify and streamline data processing of clinical ASL data. Several projects have developed as a result of this work, including evaluation of ASL in patients with multiple sclerosis and epilepsy, demonstrating groups of patients where ASL proves worthwhile and the consequent utility of this new imaging modality in clinical use.
Robin Lee Casey
Intranasal Oxytocin Treatment of Paranoia and Social Cognitive Deficits in Schizophrenia
Robin Lee Casey, Cort Pedersen
Central Regional Hospital Raleigh - Clinical Research Unit and UNC Hospital's CTRC
Social dysfunction is one of the most disabling symptoms of schizophrenia and has little to no response to treatment with antipsychotic medications. Aspects such as interpretation of social cues and interpreting and inferring others' emotions correctly can drastically limit the ability of an individual to participate in community activities or maintain meaningful relationships. Other symptoms of schizophrenia, such as paranoia and delusional thinking can be improved with antipsychotics, but are also often residual and interfere in normal social functioning. Oxytocin is a neuropeptide that is synthesized in the brain and released from the posterior pituitary. It has been shown that oxytocin receptors exist in numerous locations outside the brain, and that additionally this hormone has prosocial effects. It promotes mating behaviors, mate pair bond formation in monogamous species, increased social grooming in primates, decreased aggression and formation of social memory. Recent studies on normal human subjects indicate that oxytocin treatment increases interpersonal trust and the ability to interpret social cues and emotional expressions. Using a randomized, double-blind, placebo-controlled study we have shown that twice daily intranasal oxytocin over a two week period can significantly lower total PANSS (Positive and Negative Symptom Scale) scores and shows promising trends for decreasing both paranoia and social cognitive deficits.
Total Power Heart Rate Variability is Associated with Posttraumatic Stress Disorder in Patients Seen in the Emergency Department after Minor Motor Vehicle Collisions
Samuel McLean, Andrew McFarland
UNC, TRYUMPH Research Program
Previous studies have identified autonomic nervous system dysregulation in patients after minor trauma; such dysregulation may be involved in the generation or maintenance of posttraumatic stress disorder (PTSD). Total power heart rate variability is a measure of autonomic nervous system function, but no studies to date have examined the role it may play in the development of PTSD. The relationship between PTSD one month post-trauma and total power heart rate variability was examined in emergency department (ED) patients after minor motor vehicle collisions. Among participants (n=101), PTSD was associated with increased anxiety (r=0.403, p<0.001) and initial depressive symptoms (r=0.299, p=0.008). The presence of neck pain in the ED was also highly associated with PTSD (r=0.328, p=0.002). In multivariate analyses adjusting for age, gender, ED neck pain, and initial anger rating, the association between PTSD and total power heart rate variability (t=4.053, p<0.001) persisted. Chronic pain is associated with the development of PTSD, and the autonomic nervous system and the nociceptive axis closely interact. It is likely that total power heart rate variability can directly influence the development of PTSD, although no direct evidence currently exists. Further studies are needed to better understand the nature of the association between total power heart rate variability and the development of PTSD in patients after minor trauma.
Is there a learning curve for ablative therapy of Barrett's esophagus?
Brian Petullo, Ryan Madanick, Evan Dellon, Joseph Galanko, Nicholas Shaheen
UNC Department of Medicine, Division of Gastroenterology and Hepatology
Background: Barrett’s esophagus (BE) is a pre-malignant condition consisting of intestinal metaplasia of the lower esophageal epithelium. To prevent its progression to esophageal adenocarcinoma, several endoscopic ablative techniques have been employed to eliminate this pre-cancerous tissue, including radiofrequency ablation (RFA). Typically, multiple ablation sessions are required to fully eliminate metaplastic or dysplastic tissue.
Aim: To assess if there is learning curve for physicians performing RFA.
Methods: We performed a review of 110 patients with dysplastic BE who had undergone RFA for BE. Of these, 73 (66%) completed treatment and 69/73 (95%) had complete eradication of metaplastic and dysplastic tissue. Variables collected include percent BE resolution, pre-ablation histology, complications (chest pain, stricture, hospitalization, esophageal perforation), and sedation doses. To assess for the presence of a learning curve, the 69 subjects with complete eradication of their BE were divided into 7 groups based on the date of their first ablation session. The mean number of ablation sessions for each group was calculated.
Results: The mean age of the cohort was 67.3 years. 72% of the cohort was male. Over time, there was a significant reduction in the number of RFA sessions required to reach complete eradication of BE, from an average of 4.3 sessions in the earliest group of patients, to 2.4 sessions in the most recent group (p=0.0001 for trend). No differences in safety were noted in this time trend analysis.
Conclusions: There was a clinically and statistically significant learning curve associated with endoscopic ablation of BE, with initial subjects requiring approximately two additional treatment sessions for complete ablation. For optimal delivery, this procedure should be performed in high volume centers.
Impact of MRSA in tracheotomized children
Elizabeth Rabold and Marianne Muhlebach
UNC, Pediatric Pulmonary Medicine
Children with tracheotomies face special challenges in maintaining healthy airways. Though the procedure is often medically necessary, the presence of the foreign body in the trachea results in the loss of some of the body’s natural mechanisms to prevent colonization and infection from microorganisms such as Staphylococcus aureus. With the increasing prevalence of Methicillin-resistant Staphylococcus aureus (MRSA), we sought to identify potential risk factors for the colonization of MRSA in this population of patients. In a retrospective, cross-sectional, observational study conducted at NC Children’s Hospital, 92 children received tracheotomies between January 2008 and December 2009. We obtained tracheal aspirates from them at every subsequent routine and emergent visit to the hospital and conducted a chart review for all patients. Ages of the participants ranged from less than 1 year to 18 years. The primary indications for placement were neurologic (50%), upper airway obstruction (20%), and respiratory insufficiency (30%). All individuals were colonized with at least one organism, with oropharyngeal flora, Pseudomonas aeruginosa, and Staphylococcus aureus being the three most common. Twenty-four children (26%) had MRSA-positive aspirates during the study period, while 68 children (74%) remained MRSA-free. We compared a variety of potential risk factors between the two groups. Of note in the analysis, children with neurological disorders had a statistically higher incidence of colonization of MRSA (62.5%) than children with other indications for tracheotomy (37.5%). Though not statistically significant, duration of ICU stay at time of placement was associated with a higher incidence of colonization of MRSA (61 days compared to 47 days). Children with more severe conditions or who may have been sicker at the time of tracheotomy may have higher risks of future colonization with MRSA. Identifying risk factors for colonization with MRSA allows physicians to monitor closely those who are most vulnerable and take appropriate precautions.
Family Alert: Implementing Direct Family Activation of a Pediatric Rapid Response Team
Emily Miller Ray, M.P.H.; Rebecca Smith, M.D.; Sara Massie, M.P.H.; Jordan Erickson, B.S.; Cherissa Hanson, M.D.; Bradford Harris, M.D.; Tina Schade Willis, M.D.
NC Children's Hospital - Department of Anesthesia, Pediatric Critical Care
Background and Objectives: Recent studies show survival to discharge for in-hospital pediatric patients who suffer a cardiopulmonary arrest to be as low as 16%. Rapid response systems (RRSs) have been introduced in many hospitals to reduce cardiopulmonary arrests and mortality. A previous study at the authors’ hospital revealed that the establishment of a pediatric RRS increased the number of patient days between cardiac arrests and reduced the duration of clinical instability. At many hospitals, staff and family concerns are triggers for calling the rapid response team. By recognizing these concerns, emergency personnel can reach deteriorating patients earlier, thus preventing cardiac arrests. At our institution, we allow families to directly activate the RRS. In this presentation, by describing our own experience implementing a family-activated pediatric RRS, we identify issues that may arise during this process and share our strategies for overcoming these challenges.
Methods: A pediatric RRS was implemented at the North Carolina Children’s Hospital in August 2005. A review of first-year data revealed “family concern” as a reason for activation in 8% of calls. In response, we developed family activation in April 2007 to empower family members to seek help when serious concerns arise. We developed educational tools to increase awareness about appropriate use of the pediatric RRS and measured the level of awareness amongst families.
Results: Since the introduction of family activation, the mean number of RRT calls has increased significantly, from 16 to 24 calls per 1,000 discharges. On average, 27% of families understand when and how to activate the RRT. The median number of calendar days between cardiac arrests has increased from 34 days to 104 days since initial implementation of the RRS.
Conclusions: At our institution, family activation has created an environment where families feel empowered and are partners in reducing pediatric cardiac arrests and deaths.
Healthcare Professionals’ Perceptions of the North Carolina Medical Orders for Scope of Treatment (MOST) Form in Long-Term Care
Victoria Rollins, BS; Anthony Caprio, MD; Ellen Roberts, PhD, MPH
UNC School of Medicine, Division of Geriatrics
Background: The Medical Orders for Scope of Treatment (MOST) form is the North Carolina (NC) adaptation of the Physicians Orders for Life-Sustaining Treatment (POLST) paradigm. POLST was created to translate patient preferences regarding end-of-life care into medical orders that are honored across healthcare settings. The purpose of this pilot study is to describe the perspectives of healthcare professionals using the MOST form in two NC long-term care facilities within continuing care retirement communities (CCRCs).
Methods: Six physicians, two nurse practitioners, and two social workers from two skilled nursing facilities within CCRCs were surveyed and interviewed about their experiences and perceptions of the MOST form. Surveys were analyzed with descriptive statistics and interviews were analyzed using Atlas.ti 6.0 qualitative software.
Results: MOST was viewed as a useful clinical tool with applicability in the skilled nursing facility and in the broader CCRC. Nursing home admission and routine care planning meetings were identified as the most important times to complete this form. Social workers play an important role in introducing the form to patients/families. Nearly all (10/11) believe that the form improves communication between patients/families and providers. However, only 3/11 were aware of all review requirements. Interviewees gave varying descriptions of the scopes of treatment in section B of the form. Three-fourths viewed the Limited Additional Interventions scope of treatment as problematic. Time was the most commonly cited barrier to use of the form. Interviewees were concerned about MOST forms getting lost or not being honored outside of the long-term care setting.
Conclusion: This is the first study to describe the NC experience with the POLST paradigm from the perspective of interdisciplinary healthcare professionals. Although a few barriers were reported, overall, the MOST form was viewed as a useful tool for eliciting, documenting, and communicating treatment preferences across different settings of care.
High Fat Content and Low Lean Mass as predictors of Sub-clinical risk factors for atherosclerosis
Carlton Singleton, Francisco Lopez-Jimenez, M.D., Virend Somers, M.D., Ph.D., Ling Xu, M.D., Paulina Cruz, M.D.
Mayo Clinic in Rochester, MN
Do CT findings discriminate between histologic Type 1 and Type 2 papillary renal cell carcinoma?
Brian Munro, MD, Meredith Soles, MA, Susan Maygarden, MD, Julia Fielding, MD
UNC, Department of Radiology
Objective: To determine using CT scans whether size, relative enhancement or heterogeneity of enhancement can be used to separate histologic Type 1 from Type 2 papillary renal cell carcinoma.
Methods: This retrospective study was approved by our IRB and is HIPAA compliant. Using the electronic medical record 43 papillary tumors were confirmed at surgery (n=41) and biopsy (n=2). At pathology review, 21 (49%) were histologic Type 1 and 22 (51%) Type 2. All subjects underwent a standardized CT
protocol that included a pre-contrast and delayed (100 s) post-contrast exam to determine presence or absence of enhancement and stage of disease, with significant enhancement defined as 15HU. Tumor size was that reported at pathology. Contrast enhancement was normalized using a ratio of kidney to aortic density. The Pearson Chi square and Welch 2 sample t test were used to identify CT findings associated with histologic subtype.
Results: Tumor size ranged from 1.6cm to 12.5cm with a median of 4cm. The median size of Type 1 masses was 3.5cm and that for Type 2 was 4cm. On non-contrast enhanced images density ranged from 10-47 HU and on contrast enhanced images 18 to 90HU. 14 masses enhanced less than 15HU. When corrected for density of the aorta, the mean increase in mass enhancement for all tumors was 30%. The mean corrected heterogeneity of enhancement for all tumors was 23%. None of these findings was found to be reliable for identification of tumor histologic subtype.
Conclusion: CT findings cannot be used to differentiate histologic subtypes of papillary renal cell carcinoma. Even when measured enhancement of a renal mass is <15 HU, other factors prompt surgical
Anatomical Limitations for Endoscopic Endonasal Skull Base Surgery in Pediatric Patients
Jason R. Tatreau, BS; Mihir R. Patel, MD; Rupali N. Shah, MD; Kibwei A. McKinney, MD; Adam M. Zanation, MD
Department of Otolaryngology - Head and Neck Surgery at UNC Hospitals
Objectives/Hypothesis: Pediatric skull base surgery is limited by several boney sinonasal landmarks that must be overcome prior to tumor dissection. When approaching a sellar or parasellar tumor, the piriform aperture, sphenoid sinus pneumatization, and intercarotid distances are areas of potential limitation. Quantitative pediatric anatomical measurements relevant to skull base approaches are lacking. Our goal was to use radioanatomic analysis of computed tomography (CT) scans to determine anatomical limitations for trans-sphenoidal approaches in pediatric skull base procedures.
Study Design: A retrospective radioanatomic analysis.
Methods: Measurements included piriform aperture, sphenoid sinus pneumatization patterns, and intercarotid distances on axial scans and coronal and sagittal reconstructions. Fifty pediatric (<18 years of age) and 10 adult patients were equally subdivided into 7 age groups, and compared to determine temporal relationships among sphenoid sinus pneumatization, sphenoid bone thicknesses, and intercarotid distances.
Results: Piriform aperture width was 29% greater in adults than in patients under 2. Three-fourths of the planum and sellar face and half of the sellar floor were pneumatized by ages 6-7. Superior clival pneumatization was not evident until 12 years of age. Clival intercarotid distances were not different among groups. Drilling distances for trans-planar, trans-sellar, and trans-clival approaches are described.
Conclusions: Several potential anatomic limits must be considered in pediatric skull base surgery and these vary according to age. Piriform aperture is likely a limit only in the youngest patients (under 2 years). Sphenoid pneumatization to the planum and sella start at 3 years and complete by age 10. Clival intercarotid distances are not prohibitively narrow in any age group.
Fly on the wall: Do pediatricians meet parental expectations for beverage counseling during well-child visits?
Angela M. Vandegrift, BS, Joanne P. Finkle, RN, JD, Michael J. Steiner, MD, Eliana M. Perrin, MD, MPH.
UNC Department of Pediatrics
Background: The AAP recommends limiting sugar-sweetened beverages to help prevent childhood obesity. It is unclear what advice and strategies parents would like from pediatricians to help them make healthy beverage choices or whether pediatricians meet those expectations during well-child visits.
Objective: To determine what beverage counseling techniques parents consider helpful and whether those techniques are being used by pediatricians during well-child visits.
Methods: We used Atlas.ti software to code 24 interviews with parents of children 3-8 years old on the topic of obesity prevention counseling and identified the specific beverage counseling strategies parents consider helpful. We then audio-recorded 12 well-child visits of children 2-6 years old in an academic general pediatrics clinic to determine whether these strategies were being used by resident pediatricians. Residents being taped were only aware of the interest in their “verbal interaction” with parents. The portion of the recording focused on beverage counseling was transcribed verbatim.
Results: In interviews, parents reported confusion about which beverages and what amounts are considered healthy for young children. Several expressed a desire for pediatricians to provide more specific beverage advice during the well-child visit, including exact amount limits for various beverages. Additionally, parents asked for written handouts with recommendations to take home. A review of audio recordings revealed that pediatricians spent an average of 27 minutes per well-child visit, with an average 53 seconds devoted to beverage counseling. All 12 of the pediatricians did address beverages in some way, but counseling about specific beverage amounts was infrequent. Specific juice amount guidelines were given for four of 12 visits; specific sugar-sweetened beverage amount guidelines were given for two of 12 visits; and only one physician gave the parent a written reminder to take home.
Discussion: In this study there was a disconnect between the counseling parents identified as helpful (specific beverage quantity recommendations and take-home handouts) and the counseling provided in the exam room. Audio-recording counseling in the academic setting may be a useful teaching tool to evaluate whether delivery of health care matches expectations and recommendations.
The Interaction between the Ratio of the Width of the Greater Trochanter to the Width of the Iliac Wings and Development of Trochanteric Bursitis
Neal Viradia, Alexander Berger, Laurence Dahners
UNC School of Medicine, Department of Orthopedics
BACKGROUND: Trochanteric bursitis is a disorder which is characterized by inflammation of the bursa superficial to the greater trochanter of the femur leading to pain in the lateral hip. This bursitis most often occurs due to acute trauma or repetitive friction between the iliotibial band, greater trochanter, and the bursa. Increased prevalence of bursitis may be attributable to increased prominence of the trochanter in relation to the wings of the iliac crest.
METHODS: Participants were 202 patients from the UNC Health Care System, 101 without a known diagnosis of trochanteric bursitis and 101 with a clinical diagnosis of trochanteric bursitis. The distances between the outermost edges of greater trochanters and iliac wings were measured. T-tests for non-paired data were used to determine the significance of differences between the control and bursitis group.
RESULTS: Patients diagnosed with trochanteric bursitis had a significantly greater difference (P<0.00005) in the width of trochanters relative to the iliac wings (28± 20mm) as compared to the control group(17± 18mm). Furthermore the average ratio of trochanteric width to iliac wing width was significantly different (P<0.0005), in the bursitis group (1.09± .06) than the control group (1.05 ± .06).
CONCLUSIONS: Having a wider trochanteric width in relation to iliac wing width predisposes patients to the development of trochanteric bursitis. This lends support to the development of operations intended to narrow the trochanters in treatment of recalcitrant bursitis.
LEVEL OF EVIDENCE: This study investigates the anatomical relation of the greater trochanter and iliac wings and the development of trochanteric bursitis making this a Level III Case Control Study.
PUBLIC HEALTH – Poster
Disaster Responses in North Carolina Demonstrate the Need for Statewide Resource Allocation
Scott Cornella, Jane Brice MD, Greg Mears MD, Fran Shofer MD, Charles Cairns MD
UNC, Department of Emergency Medicine
Background: Though rare in occurrence, disasters are unique challenges for acute healthcare resources. In many states, hospitals operate at near-maximum capacity making surge capacity a concern for disaster planners. Yet data on local and statewide availability of hospital resources during actual disasters are limited. Objective: The purpose of this study was to assess the availability of hospital resources during three recent disasters in North Carolina (NC). Methods: In this observational study, information from the State Medical Asset Resource Tracking Tool (SMARTT) system was assessed during three recent disasters. SMARTT is a state-required web-based tool that tracks open and available beds and resources for all NC hospitals, health centers, and EMS systems on a daily basis. The included disasters were a series of tornadoes that struck mid-NC (Greensboro) on May 8, 2008, an explosion at a food processing plant in eastern NC (Garner) on June 6, 2009, and tropical storm Hanna which made landfall in coastal NC on September 6, 2008. Results: Within a 20 mile radius of the Greensboro tornadoes, available resources included 0 burn beds, 59 Emergency Department beds, 79 adult floor beds, 16 adult ICU beds, and 2 Operating Room beds. Within a 20 mile radius of the Garner explosion there were 0 burn beds, 96 Emergency Department beds, 139 adult floor beds, 5 adult ICU beds, and 27 Operating Room beds. Within a 20 mile radius of Tropical Storm Hanna’s landfall there were 0 burn beds, 0 Emergency Department beds, 0 adult floor beds, 0 adult ICU beds, and 0 Operating Room beds. Conclusion: NC hospitals across three distinct geographical areas appear to lack acute beds and facilities necessary to locally accommodate an influx of patients during these three disasters. These data support the need for statewide disaster planning to readily identify available hospital resources and acute care transport strategies.
Identifying Dietary Habits and Prevalence of Cardiovascular Risk Amongst Low Income Women in Rio de Janeiro, Brazil
UNC, Department of Family Medicine
Cardiovascular risk has adverse physical, social, and economic consequences that can negatively affect an individual’s quality of life. Low income has traditionally been the factor most often associated with the existence of poor nutrition habits that are correlated with high incidence of diabetes and cardiovascular disease. This study aimed to assess the cardiovascular risk and dietary habits of low income women in Rio de Janeiro, Brazil, in order to inform future interventional efforts. A reliable structured dietary recall and general health knowledge instrument was used to assess eating patterns, basic health knowledge, general health status, and cardiovascular risk as measured by anthropomorphic data. High consumption of red meat and artificially sweetened drinks combined with a low consumption of fruits and vegetables and a lack of cardiovascular exercise are contributory factors to the current obesity trend amongst low-income women in Rio de Janeiro, Brazil. Given that this population has poor access to ongoing medical care and difficulty affording medications, behavioral change may be the most viable option for improving health. Diet and exercise are two modifiable behaviors that can be targeted through future educational and intervention programs.
Personal Disaster Preparedness of Dialysis Clients
Mark Foster, Stephanie Principe, Maria Ferris, Darren DeWalt, Jane Brice
UNC, Department of Emergency Medicine
Chronic disease patients, especially those in need of periodic dialysis treatments, are one of the most susceptible subsets of patients to a lapse in treatment. The aim of this project was to interview dialysis patients in the UNC Health Care System regarding their knowledge about and preparation for a potential disaster and the resultant disruption in dialysis treatment. We completed a cross-sectional survey of persons who require dialysis care at six regional dialysis centers. Persons were approached as they received their dialysis care and were informed about the study. Interested persons were provided with a consent form and their questions answered. Consenting subjects were anonymously enrolled in the study and provided with a survey and healthy literacy test. We excluded persons who refused to participate or are mentally impaired. Enrolled subjects were evaluated in four central areas including demographic information and health literacy level, general disaster preparedness utilizing Department of Homeland Security recommended item lists, dialysis patient specific preparation for an individual to shelter in place, as well as preparatory steps for a forced evacuation. Out of 443 patients approached, 311 took the survey. 121 (39%) of respondents stored food, water, and 75% of the recommended items listed by the government. 57% claimed to have knowledge of a renal emergency diet in the event of a need to shelter in place and 42% had knowledge of another dialysis facility in the state. Our results indicate that irrespective of chosen demographic variables, the majority of subjects were largely unprepared for a potential emergency situation. Preparation by dialysis patients in North Carolina for the need to evacuate or shelter in place in the face of a disaster situation is inadequate and is independent of any demographic variable that we analyzed. Dialysis patients need to be educated regarding the risks of lack of preparation.
Nutritional Behavior of Rural Mexicans: Not what you may Believe!
Bryce Haac, Candace Mitchell, Will Rearick, Carolyn Zeimer, Christopher Nassef, Neeti Doshi, Evan Ashkin MD, Bron Skinner PhD and Philip Sloane MD
UNC School of Medicine
The growing Latino population in North Carolina experiences a high incidence of diabetes and cardiovascular disease. Studies suggest that acculturation to the typically unhealthy American diet may be partially responsible for increased obesity in this population, a risk factor for these diseases. To identify whether a return to traditional eating patterns from their home country would be a successful intervention strategy for Mexican immigrants in the US, medical student research assistants conducted structured dietary recall interviews with 364 Mexicans in 11 rural communities in Guanajuato state, Mexico. Participants reported low fruit and vegetable intake and high tortilla, salt, and soft-drink intake. In addition, participants reported eating more proteins high in saturated fat than lean proteins. These results indicate that Mexicans in Guanajuato, homeland to 11-12% of Mexican immigrants, do not practice healthy dietary habits. Contrary to popular belief, Mexicans who immigrated to the US do not come from communities where dietary habits are healthy. Instead, there is potential for large improvement in eating patterns on both sides of the border. Here in the US, interventions focusing on learning the elements of a healthy diet and integrating them into a traditional Mexican diet may be more effective than encouraging a return to traditional dietary habits.
Nonmydriatic Digital Retina Camera Can Improve Diabetic Retinopathy Screening Rates in an Enhanced Care Clinic
Bradley King, Rob Malone, PharmD and Seema Garg, MD, PhD
UNC, Department of Ophthalmology
Diabetic retinopathy (DR) is a leading cause of blindness among working age adults in the US despite availability of treatments that prevent progression of vision loss; however, < 50% of diabetics are adherent to screening guidelines. We examine DR screening rates 3 months after implementation of a population-based strategy delivered at an internal medicine clinic with remote interpretation of digital retinal images.
Results: In August through September 2009, retinal imaging was performed on 260 patients. Compliance with National Committee for Quality Assurance (NCQA) guidelines for DR screening improved to 70% compared to 65% for the 3 months prior to implementation. This observational study demonstrates that digital retinal imaging in conjunction with telemedicine can improve DR screening rates, and may help prevent vision loss among diabetics.
Disability and Hip Osteoarthritis: Associations with Education, Occupation, and Community Poverty Level
Joshua B. Knight, Leigh F. Callahan, Jack Shreffler, Jordan B. Renner, Joanne M. Jordan
Thurston Arthritis Research Center, University of North Carolina at Chapel Hill
Objective: To examine associations of education, occupation, and community poverty with disability in persons with hip radiographic OA (rOA) or symptomatic OA (sOA) in the Johnston County OA Project.
Methods: A cross-sectional analysis was conducted on participants from a pool of 4098 individuals. Participants with hip rOA, hip symptoms, or hip sOA were identified and included in corresponding subgroups. rOA was defined as Kellgren-Lawrence ≥ 2. Education (<high school (HS) or ³HS) and occupation (physically demanding or not) were individual socioeconomic status (SES) measures. Census block group poverty rate (<12%, 12-25%, >25%) was the community SES measure. Disability was measured by the Health Assessment Questionnaire (HAQ) and the Western Ontario and McMaster University (WOMAC) osteoarthritis index. Covariates were age, gender, race, BMI, and presence of knee symptoms. Race was not an effect modifier and was included as a covariate. Bivariate analyses were used with and without adjusting for covariates to find associations of disability with each of the SES effects separately. Multivariable analyses were conducted with all SES variables, adjusting for covariates and allowing for random intercepts based on block group. Separate models were run for each of the six subgroups.
Results: In unadjusted bivariate models, HAQ disability associated significantly with occupation in both subgroups, and with education and >25% poverty in hip rOA. Once adjusted for covariates, HAQ disability associated with occupation in both subgroups and with >25% poverty in hip rOA. In multivariable models, HAQ disability was associated significantly with occupation in both subgroups and with >25% poverty in hip rOA.
Conclusions: The findings underscore the importance of SES variables with disability outcomes in OA and indicate that in some cases community SES characteristics may have impact as well.
The Relationship between Knowledge and Risk for Heart Attack and Stroke
Cameron T. Lambert, Seth Vinson, Jane H. Brice MD/MPH, Frances S. Shofer PhD
UNC, Department of Emergency Medicine
Objective: Stroke and myocardial infarction (MI) represent two of the leading causes of death in the United States. Early recognition of these events allow for mitigation of disability or death. We sought to 1) compare subject’s knowledge of stroke and MI, 2) assess subject’s risk for cardiovascular disease, and 3) assess for an association between knowledge and risk. Methods: In this cross-sectional survey, adult, non-health care professionals able to understand the consenting process were presented a knowledge and risk assessment tool. Subjects were classified into three categories of cardiovascular risk (high, medium and low). Knowledge of disease epidemiology, anatomy, risk factors, symptoms, and treatment were assessed for stroke and MI separately. To determine if MI and stroke knowledge differed data were analyzed using paired t-test, McNemar’s test,ANOVA. Results: Of 500 subjects approached, 363 completed the survey. Subjects were 69% white, 28% African-American, and 49% female. Average knowledge test scores were 73.8% for stroke and 79.6% for MI (p<0.0001). Subjects were more likely to 1) recognize MI as a leading cause of death (OR 8.4, p<0.0001), 2) recognize hypertension as an important risk factor for stroke (OR 1.7, p<0.012), 3) recognize MI symptoms compared to stroke symptoms (OR 1.9, p<0.034), and 4) report the appropriate treatment window for MI (OR 6.6, 0.0001). MI and stroke knowledge test scores decreased as risk increased (p<0.001) and at every level of risk, MI knowledge was significantly higher than stroke knowledge (p<0.001). Conclusion: Knowledge about stroke and MI was modest. Subjects had better knowledge about MI than stroke overall and at every level of risk. Subjects at higher risk are less knowledgeable of the signs, symptoms, and risk factors associated with stroke when compared to MI. Potential reasons for lower stroke knowledge include the difficulty of identifying and educating individuals at high risk for stroke.
Perceptions of Diabetes in Rural Mexicans: A Frightful Reality
William Rearick, Carolyn Ziemer, Candace Mitchell, Christopher Nassef, Bryce Haac, Neeti Doshi, Bron Skinner PhD, Evan Ashkin MD, Philip Sloane MD
UNC, Department of Family Medicine
Given the increasing prevalence of Mexican migrants with pre-diabetes or diabetes, knowledge of Mexican customs and beliefs regarding diabetes may be important for public health efforts and primary care providers. Previous research in Mexican populations has documented that many Mexican believe diabetes to be caused by “susto,” referring to a “fright sickness” or “fallen spirit” resulting from a frightening or traumatic experience. To assess beliefs about the etiology of diabetes among residents of Mexican source communities for migrants to North Carolina, medical students and faculty from UNC-Chapel Hill conducted 367 interviews in 11 rural communities in Guanajuato, Mexico, a Mexican state one of the highest rates of immigration to North Carolina. Included in the interview was the item, “How would you describe diabetes?”. 34% of respondents stated that they believed diabetes to be the effect of a susto, 10% characterized diabetes as an uncontrollable disease, and another 35% responded that they did not know. Only 18% chose glucose intolerance. Chi square analysis was performed to test for an association of perception of diabetes with the following variables: age, sex, education, diabetes diagnosis, diabetes family history, annual doctor visits, and the poverty score of the participant’s community. Increased frequency of doctor visits was associated with increased likelihood of choosing the biological explanation of diabetes, but no change in prevalence of "susto" as a response. Other variables did not correlate with perception of diabetes in a statistically significant way. Several factors may contribute to the observed responses. Lack of understanding of the biological factors resulting in diabetes is one potential factor. However, the high prevalence of "susto" and "uncontrollable disease" as responses, even in those that regularly visit the doctor, suggests that many Mexicans feel that factors beyond their control are responsible for the illness. If this is the case, belief-based intervention may be more useful than educational ones that focus on biology and science.
Cancer Registry at Kamuzu Central Hospital in Lilongwe, Malawi
Cancer Registry at Kamuzu Central Hospital in Lilongwe, Malawi, Africa
No operational cancer registry currently exists in Malawi. The detection, identification, treatment and follow-up of cancer patient is suboptimal in Malawi and the establishment of a cancer registry is a crucial component in a strategy to improve the overall care of patients with cancer in this resource poor setting.
To design and implement a cancer registry in Lilongwe, Malawi at Kamuzu Central Hospital. This registry must incorporate the specific needs of each hospital department, record data compatible with the previously established Blantyre registry, record data using the World Health Organization’s (WHO) International Classification of Diseases for Oncology (ICD-O) codes, and be an electronic database accessible online.
Researchers were familiarized with cancer registries, cancer management in resource poor settings, database design and management, the Can Reg 4 software package, the ICD-O codes, and the Blantyre registry. A template from Chapel Hill was used and an electronic cancer database was designed. Upon completing the design of the electronic database, the data collection forms were constructed.
Six database pages were developed. The electronic database is currently under construction and will be operational and online by mid August. The data collection forms are currently being piloted.
Starting from nothing, a cancer registry has been designed and implemented at Kamuzu Central Hospital in Lilongwe, Malawi. Amongst other information, investigators and clinicians will have the capacity to determine the number of cancer patients seen at KCH, what type of cancer they have, and how those cancers are treated and the outcomes. This data will improve patient care and cancer management.
The Use of Nutritional and Water Hygiene Packages among HIV-Infected Mothers and Their Exposed Infants in Lilongwe, Malawi: An Evaluation of a Prevention of Mother-to-Child Transmission Postnatal Care
Jiayin Xue, Zenabu Mhango, Irving F Hoffman, Innocent Mofolo; Esmie Kamanga; James Campbell; Greg Allgood, Myron S. Cohen, Francis EA Martinson; Mina C. Hosseinipour
UNC Department of Infectious Diseases
Background: Most children with HIV are infected by vertical transmission from their mothers. Postnatal care of HIV-exposed infants in developing countries is challenging due to loss to follow-up in prevention of mother-to-child transmission (PMTCT) programs. The WHO recommends that breastfeeding, despite the risks of HIV transmission, is practiced until safe replacement feeding is available.
Methods: As an extension of PMTCT in Lilongwe, Malawi, free fortified porridge and water hygiene packages were offered to mothers currently weaning children to encourage frequent postnatal visits and to reduce diarrhea rates in infants after weaning. Patient retention and infant outcome were assessed.
Results: Most of the participants, 400 out of 475 (84.4%, 95% CI=80.8-87.5%), completed at least three monthly follow-up visits after their initial postnatal weaning visit. Nearly all of the women reported hygiene package use (99.5%), and only 74 (18.5%, 95% CI 14.8-22.7%) of the infants had diarrhea at least once over the three months period.
Conclusion: The incentives were well-received by the patients leading to high retention. Infant diarrhea rate was low compared to other studies, suggesting benefits of regular medical care with water hygiene package usage and reliable replacement feeding options. The program should be continued and expanded to improve the postnatal care of HIV-exposed infants in Malawi and perhaps in other resource constrained countries.