• P2Y receptors as regulators of lung endothelial barrier integrity

      Zemskov, Evgeny A.; Lucas, Rudolf; Verin, Alexander D.; Umapathy, Nagavedi S.; Vascular Biology Center; Department of Pulmonary and Critical Care (2011-01)
      Endothelial cells (ECs), forming a semi-permeable barrier between the interior space of blood vessels and underlying tissues, control such diverse processes as vascular tone, homeostasis, adhesion of platelets, and leukocytes to the vascular wall and permeability of vascular wall for cells and fluids. Mechanisms which govern the highly clinically relevant process of increased EC permeability are under intense investigation. It is well known that loss of this barrier (permeability increase) results in tissue inflammation, the hall mark of inflammatory diseases such as acute lung injury and its severe form, acute respiratory distress syndrome. Little is known about processes which determine the endothelial barrier enhancement or protection against permeability increase. It is now well accepted that extracellular purines and pyrimidines are promising and physiologically relevant barrier-protective agents and their effects are mediated by interaction with cell surface P2Y receptors which belong to the superfamily of G-protein-coupled receptors. The therapeutic potential of P2Y receptors is rapidly expanding field in pharmacology and some selective agonists became recently available. Here, we present an overview of recently identified P2Y receptor agonists that enhance the pulmonary endothelial barrier and inhibit and/or reverse endothelial barrier disruption.
    • Pancreatic cancer survival trends in the United States: 2001 - 2015 SEER 18 data

      Ansa, Benjamin; Institute of Public and Preventive Health (Augusta University, 2019-11-06)
    • ParaDIME: Genome-wide differential DNA methylation analyses using next generation sequencing

      Pabla, Sarabjot; Institute of Molecular Medicine and Genetics (12/27/2016)
      Epigenetic modifications are key players in the regulation of a plethora of cellular and physiological processes. DNA methylation is one of the most widely studied epigenetic modification. Genomic abnormalities in DNA methylation have been implicated in various complex diseases including cancer and autoimmunity. With advent of next generation sequencing, investigating DNA methylation patterns at genome-wide scale has become increasingly feasible. However, the pace of developing appropriate statistical methods to analyze large scale DNA methylation data has been slower. This can be attributed to both statistical and computational challenges faced by current methods. In order to overcome these statistical and computational shortcomings, we developed ParaDIME, a web application for differential DNA methylation analysis. ParaDIME tests CpG dinucleotide sites or pre-defined regions of CpG sites for differential DNA methylation using Rao-Scott chi squared test. ParaDIME not only uses a nonparametric test that accounts for differential sequencing coverage but also uses permutation testing to compute exact p values. In order to overcome computation challenges of large amount of permutations, we use parallel computing to share the workload and decrease execution time significantly. To test ParaDIME in-silico, we initially simulated bisulfitesequencing data and tested it against two most widely used methods: MethylSig and MethylKit. It performed equal or better at accurately detecting differentially methylated regions than both the methods. Especially, at important, low differences of percent methylation, ParaDIME performed better than existing tools. In order to test ParaDIME’s ability to detect biologically relevant differentially methylation regions (DMRs), it was then tested on publically available methylation data from chronic lymphocytic leukemia patients. Our method was able to detect previously known and experimentally verified DMR in CLL, especially DMRs located in Nfatc1 and FOXA2 genes. Additionally, it was able to detect other DMRs in genes present in caner related pathways. Due to ParaDIME’s ability to detect biologically relevant DMRs, we employed it in an integrative analysis study to identify epigenetically regulated genes in Sjogren’s syndrome mouse model, B6.NOD aec1/aec2. We performed reduced representation bisulfite sequencing and RNA sequencing on salivary glands of four and eighteen weeks old B6.NOD aec1/aec2 compared to age and gender matched C57BL/6 mice. After removing age and mouse model effect, we discovered 89 differentially expressed as well as differentially methylated genes. Spearman rank order correlation analysis found a significant correlation between DNA methylation and gene expression. Autoimmunity related genes Klf9 and Nfkbid showed significant negative correlation whereas, other genes like Fgf12 and Coll11a2 genes showed significant positive correlation. Subnetwork enrichment using MATISSE showed three jointly active connected subnetworks that were highly enriched in Immune system related pathways, especially, T cell and B cell activation along with cytokine signaling and endocrine system development. Evidence presented in this report presents a novel and a robust differential DNA methylation analysis method with high accuracy to detect disease-relevant DMRs. ParaDIME is a user-friendly and scalable web application with appropriate test statistic to analyze large-scale DNA methylation studies.
    • ParaKMeans: Implementation of a parallelized K-means algorithm suitable for general laboratory use.

      Kraj, Piotr; Sharma, Ashok; Garge, Nikhil; Podolsky, Robert H.; McIndoe, Richard A; Center for Biotechnology and Genomic Medicine (2008-04-28)
      BACKGROUND: During the last decade, the use of microarrays to assess the transcriptome of many biological systems has generated an enormous amount of data. A common technique used to organize and analyze microarray data is to perform cluster analysis. While many clustering algorithms have been developed, they all suffer a significant decrease in computational performance as the size of the dataset being analyzed becomes very large. For example, clustering 10000 genes from an experiment containing 200 microarrays can be quite time consuming and challenging on a desktop PC. One solution to the scalability problem of clustering algorithms is to distribute or parallelize the algorithm across multiple computers. RESULTS: The software described in this paper is a high performance multithreaded application that implements a parallelized version of the K-means Clustering algorithm. Most parallel processing applications are not accessible to the general public and require specialized software libraries (e.g. MPI) and specialized hardware configurations. The parallel nature of the application comes from the use of a web service to perform the distance calculations and cluster assignments. Here we show our parallel implementation provides significant performance gains over a wide range of datasets using as little as seven nodes. The software was written in C# and was designed in a modular fashion to provide both deployment flexibility as well as flexibility in the user interface. CONCLUSION: ParaKMeans was designed to provide the general scientific community with an easy and manageable client-server application that can be installed on a wide variety of Windows operating systems.
    • Parkinson's disease-related protein, alpha-synuclein, in malignant melanoma.

      Matsuo, Yasuhiro; Kamitani, Tetsu; Center for Molecular Chaperone/Radiobiology & Cancer Virology (2010-05-13)
      BACKGROUND: Melanoma is the major cause of skin cancer death worldwide. Parkinson's disease is a neurodegenerative disorder that is caused by mutation of alpha-synuclein or other genes. Importantly, epidemiological studies have reported co-occurrence of melanoma and Parkinson's disease, suggesting that these two diseases could share common genetic components. METHODOLOGY/PRINCIPAL FINDINGS: Recently, we found that human melanoma cell lines highly express alpha-synuclein, whereas the protein is undetectable in the non-melanoma cancer cell lines tested. To investigate the expression of alpha-synuclein in human melanoma tissues, we immunostained sections of melanoma, nevus, non-melanocytic cutaneous carcinoma, and normal skin. alpha-Synuclein was positively detected in 86% of the primary and 85% of the metastatic melanoma sections, as well as in 89% of nevus sections. However, alpha-synuclein was undetectable in non-melanocytic cutaneous carcinoma and normal skin. CONCLUSIONS/SIGNIFICANCE: The Parkinson's disease-related protein, alpha-synuclein, is expressed in both malignant and benign melanocytic lesions, such as melanomas and nevi. Although alpha-synuclein cannot be used to distinguish between malignant and benign melanocytic skin lesions, it might be a useful biomarker for the diagnosis of metastatic melanoma.
    • Participatory Process for Implementing a Colorectal Cancer Screening Intervention: An Action Plan for Local Intervention Sustainability

      Smith, Selina A.; Ansa, Benjamin E.; Sheats, Joyce Q.; Hamilton, Sandra J.; Whitehead, Mary S.; Augusta University (2015)
    • The Pathological Roles of Ganglioside Metabolism in Alzheimer's Disease: Effects of Gangliosides on Neurogenesis

      Ariga, Toshio; Wakade, Chandramohan; Yu, Robert K.; Institute of Molecular Medicine and Genetics; Institute of Neuroscience (2011-01-9)
      Conversion of the soluble, nontoxic amyloid β-protein (Aβ) into an aggregated, toxic form rich in β-sheets is a key step in the onset of Alzheimer’s disease (AD). It has been suggested that Aβ induces changes in neuronal membrane fluidity as a result of its interactions with membrane components such as cholesterol, phospholipids, and gangliosides. Gangliosides are known to bind Aβ. A complex of GM1 and Aβ, termed “GAβ”, has been identified in AD brains. Abnormal ganglioside metabolism also may occur in AD brains. We have reported an increase of Chol-1α antigens, GQ1bα and GT1aα, in the brain of transgenic mouse AD model. GQ1bα and GT1aα exhibit high affinities to Aβs. The presence of Chol-1α gangliosides represents evidence for genesis of cholinergic neurons in AD brains. We evaluated the effects of GM1 and Aβ1–40 on mouse neuroepithelial cells. Treatment of these cells simultaneously with GM1 and Aβ1–40 caused a significant reduction of cell number, suggesting that Aβ1–40 and GM1 cooperatively exert a cytotoxic effect on neuroepithelial cells. An understanding of the mechanism on the interaction of GM1 and Aβs in AD may contribute to the development of new neuroregenerative therapies for this disorder.
    • Perfluorooctanoic acid reduces viability and gene expression of peroxisome proliferator-activated receptor alpha and estrogen receptor alpha in MCF-7 cells

      Smith, April; College of Science and Mathematics (2015-10-09)
      Perfluorooctanoic acid (PFOA) is an endocrine disrupting compound found in food, water, clothes, and other consumer products. It is known to accumulate in the environment and can be taken up through ingestion, inhalation, or skin contact. It has a half-life of nearly four years in humans. PFOA has been shown to bind and activate peroxisome proliferator-activated receptors (PPARs), which are transcription factors found in mammalian cells. PPARs regulate numerous cellular activities, including proliferation and differentiation. Several studies have suggested crosstalk between PPARs and estrogen receptors (ERs). This study aimed to examine the effects of PFOA on cell viability and on PPAR and ER gene expression in MCF-7 breast cancer cells. The results showed a decline in cell viability after 48h of PFOA treatment. In addition, 24h of treatment with PFOA led to a significant decrease in PPARα and ERα, but not PPARβ, PPARγ, or ERβ. Begin Time: 28:30 End Time: 50:40
    • Physical interaction and functional coupling between ACDP4 and the intracellular ion chaperone COX11, an implication of the role of ACDP4 in essential metal ion transport and homeostasis.

      Guo, Dehuang; Ling, Jennifer X; Wang, Mong-Heng; She, Jin-Xiong; Gu, Jianguo; Wang, Cong-Yi; Center for Biotechnology and Genomic Medicine; Department of Physiology (2008-01-16)
      Divalent metal ions such as copper, manganese, and cobalt are essential for cell development, differentiation, function and survival. These essential metal ions are delivered into intracellular domains as cofactors for enzymes involved in neuropeptide and neurotransmitter synthesis, superoxide metabolism, and other biological functions in a target specific fashion. Altering the homeostasis of these essential metal ions is known to connect to a number of human diseases including Alzheimer disease, amyotrophic lateral sclerosis, and pain. It remains unclear how these essential metal ions are delivered to intracellular targets in mammalian cells. Here we report that rat spinal cord dorsal horn neurons express ACDP4, a member of Ancient Conserved Domain Protein family. By screening a pretransformed human fetal brain cDNA library in a yeast two-hybrid system, we have identified that ACDP4 specifically interacts with COX11, an intracellular metal ion chaperone. Ectopic expression of ACDP4 in HEK293 cells resulted in enhanced toxicity to metal ions including copper, manganese, and cobalt. The metal ion toxicity became more pronounced when ACDP4 and COX11 were co-expressed ectopically in HEK293 cells, suggesting a functional coupling between them. Our results indicate a role of ACDP4 in metal ion homeostasis and toxicity. This is the first report revealing a functional aspect of this ancient conserved domain protein family. We propose that ACDP is a family of transporter protein or chaperone proteins for delivering essential metal ions in different mammalian tissues. The expression of ACDP4 on spinal cord dorsal horn neurons may have implications in sensory neuron functions under physiological and pathological conditions.
    • Ploidy status and copy number aberrations in primary glioblastomas defined by integrated analysis of allelic ratios, signal ratios and loss of heterozygosity using 500K SNP Mapping Arrays.

      Gardina, Paul J; Lo, Ken C; Lee, Walter; Cowell, John K.; Turpaz, Yaron; GHSU Cancer Center (2008-10-30)
      BACKGROUND: Genomic hybridization platforms, including BAC-CGH and genotyping arrays, have been used to estimate chromosome copy number (CN) in tumor samples by detecting the relative strength of genomic signal. The methods rely on the assumption that the predominant chromosomal background of the samples is diploid, an assumption that is frequently incorrect for tumor samples. In addition to generally greater resolution, an advantage of genotyping arrays over CGH arrays is the ability to detect signals from individual alleles, allowing estimation of loss-of-heterozygosity (LOH) and allelic ratios to enhance the interpretation of copy number alterations. Copy number events associated with LOH potentially have the same genetic consequences as deletions. RESULTS: We have utilized allelic ratios to detect patterns that are indicative of higher ploidy levels. An integrated analysis using allelic ratios, total signal and LOH indicates that many or most of the chromosomes from 24 glioblastoma tumors are in fact aneuploid. Some putative whole-chromosome losses actually represent trisomy, and many apparent sub-chromosomal losses are in fact relative losses against a triploid or tetraploid background. CONCLUSION: These results suggest a re-interpretation of previous findings based only on total signal ratios. One interesting observation is that many single or multiple-copy deletions occur at common putative tumor suppressor sites subsequent to chromosomal duplication; these losses do not necessarily result in LOH, but nonetheless occur in conspicuous patterns. The 500 K Mapping array was also capable of detecting many sub-mega base losses and gains that were overlooked by CGH-BAC arrays, and was superior to CGH-BAC arrays in resolving regions of complex CN variation.
    • Positive Selection of Cd4+ T Cells Is Induced in Vivo by Agonist and Inhibited by Antagonist Peptides

      Kraj, Piotr; Pacholczyk, Rafal; Ignatowicz, Hanna; Kisielow, Pawel; Jensen, Peter; Ignatowicz, Leszek; Institute of Molecular Medicine and Genetics (2001-08-20)
      The nature of peptides that positively select T cells in the thymus remains poorly defined. Here we report an in vivo model to study the mechanisms of positive selection of CD4+ T cells. We have restored positive selection of TCR transgenic CD4+ thymocytes, arrested at the CD4+CD8+ stage, due to the lack of the endogenously selecting peptide(s), in mice deficient for H2-M and invariant chain. A single injection of soluble agonist peptide(s) initiated positive selection of CD4+ transgenic T cells that lasted for up to 14 days. Positively selected CD4+ T cells repopulated peripheral lymphoid organs and could respond to the antigenic peptide. Furthermore, coinjection of the antagonist peptide significantly inhibited agonist-driven positive selection. Hence, contrary to the prevailing view, positive selection of CD4+ thymocytes can be induced in vivo by agonist peptides and may be a result of accumulation of signals from TCR engaged by different peptides bound to major histocompatibility complex class II molecules. We have also identified a candidate natural agonist peptide that induces positive selection of CD4+ TCR transgenic thymocytes.
    • Post-translational regulation of NADPH Oxidase 5 (Nox5) mediated via Phosphorylation and SUMOylation

      Pandey, Deepesh; Vascular Biology Center (2011-03)
      Increased levels of reactive oxygen species (ROS) are a hallmark of cardiovascular disease and are most prominently observed in blood vessels from humans and animals with diabetes, atherosclerosis and hypertension [1]. The NADPH oxidase (Nox) family of enzymes is comprised of seven members, Nox 1-5 and Duox 1 and 2 [2] has been shown to be a major source of ROS including superoxide (O2") and hydrogen peroxide (H2O2) in vascular cells [3]. Nox5 was the most recent of the conventional Nox enzymes to be identified and because it has been lost from rodent genomes (mice and rats) which have become our primary models for experimentation, very little is known about the molecular regulation and functional significance of Nox5. Our first goal was to determine whether Nox5 and its splice variants a, P, 8, y andNox5 Short (e) are expressed in human blood vessels. We detected Nox5 mRNA and protein expression in human blood vessels, smooth muscle cells and endothelial cells, but not in fibroblasts. The primary splice variants of Nox5 detected were a and P whereas 5 and y were undetected. We also found that Nox5 a and p were active and produced extracellular superoxide and H2O2, while Nox5, 5, y and 8 did not produce measurable ROS. As much as we lack knowledge about functional significance of Nox5, we are not so far ahead in understanding its molecular regulation. The mechanisms controlling the activity of NADPH oxidase 5 (Nox5) are unique in that they appear to be independent of the protein: protein interactions that coordinate the activation of other Nox isoforms [4]. Instead, the primary driving force for Nox5 activity is calcium [5]. While calcium is absolutely required for Nox5 activity, discrepancies between the amount of calcium needed to initiate ROS production versus that measured inside cells has led to the discovery by our laboratory and others that the calcium sensitivity of Nox5 can be modified by the specific phosphorylation of serine/threonine residues in response to the protein kinase C (PKC)-agonist, PMA resulting in a sustained activation of Nox5 at resting levels of calcium [6, 7]. However, the specific kinase(s) mediating the phosphorylation and activation of Nox5 are not known and their identification was the goal of our study. Using pharmacological inhibitors, dominant negative mutants and knockdown of endogenous genes (MEK1, MEK2 and CAMKIIa) using siRNA approach, we demonstrated that MEK1/2-ERK1/2 and CAMKIIa signaling pathways can positively regulate Nox5 activity by inducing the specific phosphorylation of S498 and S475, respectively. While much attention has been given to the mechanisms that positively regulate Nox activity, little is known about mechanisms that suppress Nox function. Cellular stress arising from changes in osmotic pressure, heat, cold etc are potent stimuli for protein SUMOylation. Importantly, oxidative stress arising from increased ROS is one of the best recognized stimuli for regulating protein SUMOylation [8, 9]. Hence, we investigated whether SUMO could influence the activity of Nox and thus limit the damaging effects of these molecules. We found that SUMO-1 and the SUMO-specific conjugating enzyme, UBC-9 potently suppressed the activity of Nox5 as well as other Nox isoforms (Noxl, 2, 3 and 4). We also found that co-expression of SUMO-1 does not result in the SUMOylation of Nox5 and that mutation of predicted sites of SUMOylation and conserved lysines on Nox5 failed to prevent the SUMO-1 driven inhibition of ROS production. In summary, we have identified the expression of Nox5 and more specifically the and p splice variants in human blood vessels and tissues. Our data suggest that Nox5 a and p are the only variants capable of producing ROS in human blood vessels, but also that the inactive variants can function as dominant negatives. Additionally, we have shown that MAPK and CAMKIIa signaling pathways positively regulate Nox5 activity via changes in phosphorylation whereas SUMO-1 negatively regulates activity through a yet to be defined mechanism.
    • PPAR-c Regulates Carnitine Homeostasis and Mitochondrial Function in a Lamb Model of Increased Pulmonary Blood Flow

      Sharma, Shruti; Sun, Xutong; Rafikov, Ruslan; Kumar, Sanjiv; Hou, Yali; Oishi, Peter E.; Datar, Sanjeev A.; Raff, Gary; Fineman, Jeffrey R.; Black, Stephen M.; et al. (2012-09-4)
      Objective: Carnitine homeostasis is disrupted in lambs with endothelial dysfunction secondary to increased pulmonary blood flow (Shunt). Our recent studies have also indicated that the disruption in carnitine homeostasis correlates with a decrease in PPAR-c expression in Shunt lambs. Thus, this study was carried out to determine if there is a causal link between loss of PPAR-c signaling and carnitine dysfunction, and whether the PPAR-c agonist, rosiglitazone preserves carnitine homeostasis in Shunt lambs.
    • Predicting Impaired Extinction of Traumatic Memory and Elevated

      Nalloor, Rebecca Ipe; Bunting, Kristopher M.; Vazdarjanova, Almira; Brain & Behavior Discovery Institute; Department of Neurology (2011-05-18)
      Background: Emotionally traumatic experiences can lead to debilitating anxiety disorders,
    • Prenatal alcohol exposure triggers ceramide-induced apoptosis in neural crest-derived tissues concurrent with defective cranial development

      Wang, G; Bieberich, Erhard; Institute of Molecular Medicine and Genetics (2010-05-27)
      Fetal alcohol syndrome (FAS) is caused by maternal alcohol consumption during pregnancy. The reason why specific embryonic tissues are sensitive toward ethanol is not understood. We found that in neural crest-derived cell (NCC) cultures from the first branchial arch of E10 mouse embryos, incubation with ethanol increases the number of apoptotic cells by fivefold. Apoptotic cells stain intensely for ceramide, suggesting that ceramide-induced apoptosis mediates ethanol damage to NCCs. Apoptosis is reduced by incubation with CDP-choline (citicoline), a precursor for the conversion of ceramide to sphingomyelin. Consistent with NCC cultures, ethanol intubation of pregnant mice results in ceramide elevation and increased apoptosis of NCCs in vivo. Ethanol also increases the protein level of prostate apoptosis response 4 (PAR-4), a sensitizer to ceramide-induced apoptosis. Prenatal ethanol exposure is concurrent with malformation of parietal bones in 20% of embryos at day E18. Meninges, a tissue complex derived from NCCs, is disrupted and generates reduced levels of TGF-b1, a growth factor critical for bone and brain development. Ethanol-induced apoptosis of NCCs leading to defects in the meninges may explain the simultaneous presence of cranial bone malformation and cognitive retardation in FAS. In addition, our data suggest that treatment with CDP-choline may alleviate the tissue damage caused by alcohol.
    • Prevention and Treatment of Cardiovascular Disease in Adolescents and Adults through the Transcendental Meditation(®) Program: A Research Review Update.

      Barnes, Vernon A.; Orme-Johnson, David W; Georgia Prevention Institute (2012-08)
      The pathogenesis and progression of cardiovascular diseases are thought to be exacerbated by stress. Basic research indicates that the Transcendental Meditation(®) technique produces acute and longitudinal reductions in sympathetic tone and stress reactivity. In adolescents at risk for hypertension, the technique has been found to reduce resting and ambulatory blood pressure, left ventricular mass, cardiovascular reactivity, and to improve school behavior. Research on adults with mild or moderate essential hypertension has reported decreased blood pressure and reduced use of anti-hypertensive medication. The technique has also been reported to decrease symptoms of angina pectoris and carotid atherosclerosis, to reduce cardiovascular risk factors, including alcohol and tobacco use, to markedly reduce medical care utilization for cardiovascular diseases, and to significantly decrease cardiovascular and all-cause morbidity and mortality. These findings have important implications for inclusion of the Transcendental Meditation program in efforts to prevent and treat cardiovascular diseases and their clinical consequences.(®)Transcendental Meditation and TM are trademarks registered in the US. Patent and Trademark Office, licensed to Maharishi Vedic Education Development Corporation and are used with permission.
    • Problem Sets allow for multiple competency acquisition in first year neuroscience course

      Lameka, Megan; Department of Cellular Biology and Anatomy (2016-03)
      Self-directed learning (SDL) is an expected element of medical education programs. LCME standard 6.3 requires that students engage in all the following components of SDL as a unified sequence: identify, analyze, and synthesize information relevant to their learning needs, assess the credibility of information sources, share the information with their peers and supervisors, and receive feedback on their information-seeking skills. A classic tradeoff of problem-based learning (PBL) and lecture oriented pedagogies lies between life-long learning skills and content coverage. Problem sets were developed to ensure coverage of learning objectives while allowing students to engage in SDL as defined by the LCME. The neuroscience curriculum for first year medical students at the Medical College of Georgia was restructured to include problem sets in place of lectures related to special senses, somatosensory, motor systems and mental health. The purpose o f this study was to document whether problem sets provided students effective engagement in SDL, and to determine if medical knowledge competency suffered as a result of this shift in pedagogical strategy. Small groups of four students met to evaluate, solve, and discuss each problem set in a series of three meetings. Students were provided learning objectives, cases, and associated discussion and supporting questions. Students initiated a problem set by reviewing learning objectives and cases, identifying individual learning needs, and developing an individual inquiry strategy. During the subsequent meeting, students shared information learned and discussed responses to discussion questions. The final meeting involved a discussion of the problem sets between two groups with a faculty facilitator. Groups were randomly assigned discussion questions and students took turns presenting their findings. Over the course of four problem sets, each student presented findings for two discussion questions. Faculty facilitators used rubrics to assess student competency in all SDL domains. To document student engagement in SDL, data from student assessments were tabulated. To determine whet her medical knowledge was negatively affected by replacing lectures with SDL, student performance on 19 test items mapped to learning objectives covered in problem sets was compared with the same test items mapped to learning objectives covered in lecture in the previous year. Students scored 4.8 ±± 0.5 out of 5 on their ability to identify and analyze information relevant to learning needs, 4.6 ±± 0.6 out of 5 on their ability to use credible sources, and 4.7 ±± 0.6 out of 5 on their ability to effectively communicate information. A two-tailed t-test of percentage correct for all test items indicated no statistically significant differences in student performance on test items mapped to learning objectives (84.4±±10.4 % [lectures] vs. 85.7±±11.5[SDL], p=.71, d=.12). This study shows that students effectively engaged in SDL using problem sets without negatively impacting coverage of medical knowledge. More study is needed to determine if SDL skills improved as a result of problem sets. Future steps include assessment of long term retention of medical knowledge resulting from SDL vs. lecture. In conclusion, problem sets as a pedagogical approach achieved multiple competency-based objectives by providing students an opportunity to develop life-long learning skills and acquire medical knowledge.